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Plenary Lectures

PL 01

PL 02

SLEEP-WAKE REGULATION BY PROSTAGLANDINS D2 AND E2 O. Hayaishi Although we spend almost one third of our lifetime sleeping in bed or somewhere else, the molecular m e c h a n i s m of sleep-wake regulation has thus far been very little understood. During the last several decades, an intensive search for endogenous sleep-regulating substances has been carried out in a number of laboratories throughout the world. In this presentation, I wish to briefly review current knowledge about the sleep-regulating activity of prostaglandins and to discuss (i) Prostaglandins and their receptors in the brain (2) Sleep-inducing effect of PGD2 (3) Awaking effect of PGE2 (4) Other sleep-regulating substances and their relation to PGD2 and PGE2 (5) Tentative conclusions and hypothesis. Finally I would like to propose the working hypothesis that prostaglandins PGD2 and E2 induce sleep and wakefulness, respectively, and that the balance of these two substances in t.heir respective center is, at least in part, responsible for the sleep-wake cycle. Director, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita Osaka 565, Japan

ESS~I~TIAL DRUGS FOR ALL IN THE YEAR 2000 REALITY OR FICTION ? I. Darmansj ah Drugs are an essential part of health service and therefore they should be available and accessible sufficiently in terms of variety, quantity, as well as quality, where they are needed. Unfortunately this has not always been able to attain in many countries where sources of funds are restricted and priority has been given to othe~ pressing country problems. But apart from the last mentioned, even affluent countries have difficulties in coping with the global trend of increased drug consunption. Since its first conception of the WHO mediated Essential 9 Drugs Policy,which is a c(mponent of a National Drug Policy, in 1977, it became evident that a limited n%~aber of drugs (the real number is not important, hut the principle is) is satisfactory to cope with 90% of real health needs. Inplementing an Essential Drugs Policy however may mean two possibilities; for affluent countries this would mean depriving one from a wider choice of drugs, hut for many developing countries the availability of essential drugs would mean an even larger budget for drug procur~nent. Rich as well as poor countries however, will face their own problems as regards to drug use an ~he ~ a r 2000. In the wealthy countries the increased demand for drugs and escalating drug prices will result in higher drug expenditure which is nowadays illustrated by the Japanese situation with an annual per capita drug censtmlotion of over $ 200. In developing countries drug expenditure is in the range of a few dollars per capita with a very skewed distribution, and here the problem is one of nonaffordance for sizable percentages of populations. While it was anticipated in the 70-s that the proportion of drug cons~nption of developing countries would increase in relation to the industrialized countries, the WHO Report on the "World Drug Situation" (1988) reveals a proportional decline of pharmaceutical consumption in the third world fram 24 % in 1976 to 2 1 % in 1985, while its population have increased from a proportion of 73 to 75 % of the whole world. Although many factors do obscure this -

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PL 04

Cont. PL 02 picture, surveys showed that in more than I00 developing countries a large part of the population do not get access to drugs. It is clear that adequate drug use in developing countries is hampered by poverty, while both in developed countries and the upper segment in developing countries an overuse is likely to continue. A delicate balance ought to be struck between satisfying economic needs for drug * develolxnent and real health needs. With only ii years ahead it seems improbable that the availability of essential drugs in the year 2000 will be reality for all of us, unless the econcmic situation changes for the bettezment of developing countries. Now, there is even more reason to limit the use of inessential drugs and for goverr~aents to reappraise their National Health and Drug Policies and reformulate their political will. These should result in smoothening conflicts of interests which are so numerous in the field of drugs, The participation of clinicians to accept and impl~ment the Essential Drugs Concept and Polic,y is still far frc~ reality; more needs to be done to inform and convert prescribers on the still widespread misconceptions related to Essential Drugs. _Meanwhile, Rational Drug Use as part of the WHO Drug Action Programme must be canloaigned in each (developing) country to form the strong basis for therapy, which is the ultimate goal of the Essential Drugs Concept. But, ...... who should hell the cat ? Department of Pharmacology, University of Indonesia, 6 Salemba, Jakarta 10430, Indonesia.

S. Gershon Decrements of cognitive function occur most commonly and to a major extent in the pathological disorders associated with aging. SDAT (Senile Dementia Alzheimers' Type) and MID ( M u l t i - l n f a r c t Dementia) are the key c l i n i c a l disorders in which cognitive d e f i c i t s present serious c l i n i c a l and public health problems. A broader scope of such dysfunctions also occur in neurological disorders such as stroke, c l i n i c a l head i n j u r y , attention d e f i c i t disorders and drug induced d e f i c i t s . Recently, age associated memory impairment (AAMI) has been described as an issue of c l i n i c a l and academic i n t e r e s t as well as a p o t e n t i a l t a r g e t population f o r evaluation of new cognition enhancing agents. Treatment s t r a t e g i e s have concentrated on SDAT and MID where postulated e t i o l o g i e s have presented ent i ci ng treatment approaches. As a r e s u l t , e a r l y attempts to ameliorate memory d e f i c i t s focused on increasing blood flow or the supply of oxygen to the brain. In recent years, research has been directed mainly at the chol i ner gi c nervous system because a number of s i g n i f i cant changes occur within the c h o l i n e r g i c system in brains of SDAT subjects and because agents that i n t e r f e r e with normal c h o l i n e r g i c function d i s r u p t learning and memory. However, the c h o l i n e r g i c system is not the only neurotransmitter system to be af f ec te d by SDAT. I t is also not the only neurotransmitter system suspected of playing a role in learning and memory. Attempts have been made at correcting c h o l i n e r g i c d e f i c i t s as well as manipulation of the other brain neurotransmitter systems. Other modalities have included psychostimulants, metabolic enhancers, neuropeptides and nootropics. The presentation w i l l c r i t i c a l l y assess the data from such c l i n i c a l t r i a l s and w i l l present information on some new classes of agents c u r r e n t l y under i n v e s t i g a tion. Samuel Gershon, M.D.; U n i v e r s i t y of Pittsburgh; Western Psychiatric I n s t i t u t e & C l i n i c ; 38110'Hara Street; Room E-1019; Pittsburgh, PA 15213

PL 03 COMPUTER MODELING AND PHARMACEUTICAL RESEARCH

THERAPEUTIC APPROACHES TO THE TREATMENT OF COGNITIVE IMPAIRMENT

STRUCTURAL

DATABASES

IN

K. Mueller, H.J. Ammann, D.M. Doran, P.R. Gerber, K. Gubernator, G. Schrepfer FaCilities for quick manipulation, examination, and comparison of complex three-dimensional molecular structures are essential prerequisites in modern structure-oriented chemical research. They are provided by our Computer Modeling systems RIMG (Roche Interactive Molecular Graphics) and MOLOC (MOdeling on LOw-Cost terminals), which have been developed at Hoffmann-LaRoche, Basel. These modeling systems are highly functional expert systems. They are built around powerful generally applicable united-atom force field methods. They are equipped with novel algorithms for structural superposition, macrocyclic conformation analysis, and structural screen facilities. They are linked to the two database systems ROCSD (Roche Cambridge Structural Database) for X-ray structures of small molecules (original data from the Cambridge Structural Datafiles) and ROPDB (Roche Protein Structural Database) for protein X-ray structures (original data from the Brookhaven Protein Datafiles). Both databases have been specially designed to allow us quick search and retrieval of substructural information. It is the effective combination of powerful modeling, structural screening, and data compacting tools with a quick access to a wealth of three-dimensional structure information, which makes our expert systems to very potent research instruments. Their use is illustrated by examples taken from recent research projects. F. Hoffmann-La Roche & Co. AG, Central Research Units, CH-4002 Basel, Switzerland.

AS

PL 05 ATHEROSCLEROSIS G V R Born

- WHAT

CHANCES

FOR

DRUGS?

The cautious answer is - better all the time, as increased understanding of the pathogenesis is opening new intervention possibilities. The importance of this understanding can be gauged by the enormous effort and expense invested in anti-platelet and thrombolytic drugs: although vital, these drugs chase horses after the stable door is closed. The need for concentrating on drugs against the dangerous, ultimate consequences of atherosclerosis is, of course, imposed by its tendency to progress without clinical manifestations. This has also restricted possibilities for determining therapeutic effectiveness in the earlier stages of the disease. Angiographic techniques under development are beginning to overcome these limitations, with respect to reversibility as well as to prevention. The strong and causal relation established between the risk of coronary heart disease and elevated serum cholesterol levels constitutes the basis for treatment of hyperlipidaemias, by diet alone or with lipid-lowering drugs. Their different modes of action now include promising HMG-CoA reductase inhibitors. Other conceivable drug interventions through diminishing lesion development are by inhibiting uptake and modification of low density lipoprotein; by antagonising cellular proliferation; by reducing calcium deposition; and by preventing plaque fissure. Some of these possibilities are under investigation.

sodium nitroprusside and phenylephrine were infused to vary the degree of baroreceptor activity. The alpha?-adrenoceptor antagonists yohimbine and rauwoYscine shifted the plasma noradrenaline versus sympathetic nerve activity function curve in such a way that, for a given rate of sympathetic firing, the noradrenaline concentration was higher than in the absence of the antagonists, indicating the physiological operation of presynaptic alpha2-adrenergic autoinhibition at postganglionic sympathetic neurones. Activation by the endogenous agonist makes presynaptic autoreceptors interesting from the physiological point of view, but at the same time hinders their exact pharmacological characterization because the endogenous transmitter often is present in the receptor biophase at unknown concentrations. Single pulse stimulation of brain slices is a recently developed possibility to evoke an easily measurable radiolabelled transmitter release free from autoinhibition and, hence, to determine "true" agenist potencies and antagonist affinities at presynaptic autoreceptors. One result is that, in contrast to what was believed, phentolamine blocks presynaptic serotonin autoreceptors in rat and rabbit brain. The increase, by phentolamine, of the release of serotonin is not due to removal of a presumed alpha?-noradrenergic heteroinhibition but to b~ockade of the 5-HT I receptor-mediated presynaptic autoinhibition. Institut fHr Pharmakologie und Hermann-Herder-Strasse 5, D-7800 Br., Germany

Toxikologie, Freiburg i.

Department of Pharmacology, King's Colleqe, Strand, London WC2R 2LS England.

PL 06

PL 07

PHYSIOLOGY AND PHARMACOLOGY OF PRESYNAPTIC AUTORECEPTORS K. Starke, N. Limberger and B. Szabo

GENE TECHNOLOGY AS A SOURCE OF NEW DRUGS H. G. Gassen Rarely a method in biology has influenced neighbouring disciplines such as medicine and biotechnology comparable to gene technology. In 1972 Cohen and Boyer discovered that foreign DNA when brought into a bacterial cell in form of a plasmid is duely propagated..The new genetic information is needless of its origin - transcribed into RNA which may be translated in a protein. By this basic experiment biology turned into an information handling science. The discovery of the mosaic structure of eukaryotic genes, the mechanism of antibody diversity or mobile genetic elements was due to the application of DNA recombination technics. Gene technology proved to be a valuable method for the production of new drugs, especially h u m a n therapeutic proteins. Initially well known drugs such as insulin or growth hormones could be produced in unlimited quantities and higher purities by recombinant microorganisms. Next, new compounds turned up such as interleukines and growth factors which could only be isolated and identified by recombinant DNA techniques. In the years to come the battery of techniques available will be used to optimize the synthesis of low molecular weight nonprotein therapeutics. In the long run, however, pharmacology will turn back to chemistry, but on a better biological background. The practical aspects of tho lecture will concentrate on the interaction of proteinases and their inhibitors and on the

Many neurones express autoreceptors, i.e., receptors for their own transmitter. The effect mediated by autoreceptors located in the somadendritic region often is inhibition of action potential generation, whereas the effect mediated by autoreceptors at the terminals presynaptic autoreceptors - often is inhibition of action potential-evoked transmitter release. Neurones express many receptors which normally remain silent because the respective endogenous agonist never reaches them at sufficient concentrations; such receptors can be activated only pharmacologically by administration of exogenous agonists. For several presynaptic autoreceptors, however, activation by the endogenous agonist has been demonstrated, as shown by the following three examples. First, in slices of rabbit brain, the release of noradrenaline, dopamine, serotonin and acetylcholine elicited by the first pulse of a train of 4 or 8 pulses is much higher than the release elicited by the folldwing pulses. Appropriate autoreceptor antagonists greatly attenuate this decrease in per pulse release, indicating that the decrease is due to endogenous, autoreceptor-mediated inhibition. Second, local application of the appropriate autoreceptor antagonists into dialysis tubes implanted into the brain increases the local release of noradrenaline and depamine in freely moving rats, indicating presynaptic autoinhibition in the central nervous system in vivo (Dennis et al., J. Pharmacol. exp. Ther. 241, 642, 1987; Imperato and Di Chiara, Eur. J. Pharmacol. 156, 385, 1988). Third, we recently studied blood pressure, postganglionic renal sympathetic nerve activity and the plasma noradrenaline level in anaesthetized rabbits;

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Cont. PL 07 morphology of the blood-brain barrier. Proteinase inhibitors are excellent model components to study the specificity of protein-protein interaction. Furthermore, they represent valuable drugs for the treatment of inflammation. Chemical gene synthesis as well as site-directed mutagenesis are the major tools to optimize the inhibitory action of these proteins in the sense of protein design. Subtractive cloning may be used to characterize the proteins of the brain capillary endothelium which represent the basic principle of the blood-brain barrier. The genes for proteins such as the ~' -glutamyltranspeptidase, the glucose transporter or the apolipoprotei n A1 serve as genetic markers to investigate the influence of the cell environment - for example interactions with astrocytes - on the function and morphology of the brain-specific endothelium cells. A better understanding of the structure of this barrier may help to clarify the transport problems involved in metabolite exchange between the blood and the brain. Institut ffir Biochemie der Technischen Hochschule Darmstadt, Petersenstr. 22, D-6100 Darmstadt

PL 08 ENDOGENOUS' OPIATE ALKALOIDS S. Spector Endogenous codeine and morphine were identified in rat brain by immunological determination following HPLC. To demonstrate occurrence of a biosynthetic pathway to morphine in mammals similar to that used by the poppy plant (+) salutaridine, ( - ) , thebaine and (-) codeine were administered to rats intravenously. These compounds which are intermediates in the synthesis of morphine in Papaver Somniferum, caused a marked increase in the codeine and morphine levels in rat tissues. The concentrations of these two opiate alkaloids seems to be distributed uniformly in the cortex, midbrain, pons/medulla and cerebellum. The spinal cord and the adrenal gland have high levels of morphine and codeine and the adrenal has more codeine than morphine. The levels of morphine in the spinal cord and the urinary excretion of morphine are elevated in the a r t h r i t i c rat model. Extracted alkaloid samples from the a r t h r i t i c rats spinal cord were analyzed by GC-mass spectrometry and found molecular ions identical with morphine and codeine. The possible physiological roles of endogenous morphine and codeine w i l l be discussed. Roche Institute of Molecular Biology, Department of Neurosciences: Nutley, New Jersey 07110, U.S.A.

PL 09 THE DILEMMA OF DRUGDEVELOPMENTFOR TROPICAL DEVELOPING COUNTRIES S. Bergstr~m Improving the health status in developing countries is often a complex and d i f f i c u l t problem related to education and development. The proper use and distribution of the most common "essential" drugs is in many areas s t i l l not possible. Another problem has been the r e l a t i v e l y small research and development e f f o r t s - both in academies and industry - on some of the widespread diseases and problems of tropical countries lacking effective therapeutic or preventive methods. Other problem has to be solved with innovative approaches when research products are to be brought to effective use in the health services in developing countries. Some of these problems will be reviewed. Karolinska I n s t i t u t e t , Box 60250, S-IO4 Ol Stockholm

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Symposia

S 01.01 G E N E T I C POLYMORPHISMS OF DRUG M E T A B O L I Z I N G ENZYMES: MOLECULAR MECHANISMS Urs A. Meyer, D. M. Grant and M. Blum For m a n y of the known d r u g m e t a b o l i z i n g enzymes genetic p o l y m o r p h i s m s have been d e m o n s t r a t e d or are suspected. These p o l y m o r p h i s m s give rise to distinct subgroups in the population which differ in their ability to p e r f o r m a c e r t a i n drug b i o t r a n s f o r m a t i o n reaction. The molecular M e c h a n i s m s of three common p o l y m o r p h i s m s have been studied in this laboratory. The d e b r i s o q u i n e / s p a r t e i n e - t v p e p o l v m o r p h i s m of drug oxidation affects the m e t a b o l i s m by cytochrome P450IIDI of over 25 clinically used drugs including ~ - a d r e n e r g i c blocking agents, antiarrhythmics, antidepressants, opioids and others. A P450IIDI cDNA has been prepared and the locus of the IIDI gene (CYP2D) on chromosome 22 has been characterized. Several m u t a tions have been identified in the DNA derived from p r e m R N A of livers of poor m e t a b o l i z e r s (PM) of debrisoquine, all leading to deficient synthesis or unstable P450IIDI (i, 2). In leucocyte DNA of families of subjects phenotyped in vivo as poor m e t a b o l i z e r s of d e b r i s o quine, two different restriction fragment length polymorphisms (RFLPs) associated with the PM phenotype were detected with the P450IIDI cDNA. At least one mutated allele of the IIDI gene can be d e m o n s t r a t e d in DNA of 75 % of poor m e t a b o l i z e r s of d e b r i s o q u i n e (2). The m e D h e n y t o i n - t y p e p o l v m o r D h i s m affects the m e t a b o l i s m of mephenytoin, nirvanol, m e p h o b a r bital, hexobarbital, propranolol and d i a z e p a m and is caused by a deficiency of a P450 (P450meph, P450MP) of the IIC family. However, w h i c h

one of the m u l t i p l e genes of this family is affected has not yet been determined (3,4). The p o l y m o r p h i s m of N - a c e t v l t r a n s f e r a s e (NAT) affects the m e t a b o l i s m of a wide v a r i e t y of arylamine and hydrazine drugs. It was first studied by purifying and c h a r a c t e r i z i n g NAT. Two forms of NAT could be separated by ionexchange c h r o m a t o g r a p h y of human liver cytosols. In livers of slow acetylators a 31 kDa protein recognized by anti-NAT antibodies was d r a s t i c a l l y reduced or absent (5). We have isolated from genomic libraries of a p o s i t i v e l y identified heterozygous rapid acetylator a gene (hnatb) w h i c h on expression produces a p r o t e i n with the same activity and Mr as p o l y m o r p h i c NAT. Probes derived from this gene are presently used to characterize the mutation(s) causing absent NAT in slow acetylators. 1 Gonzalez, F.J., Skoda, R.C., Kimura, S., Umeno, M., Zanger, U.M., Nebert, D.W., Gelboin, H.V., Hardwick, J.P. & Meyer, U.A. Nature 331, 442-446 (1988). 2 Skoda, R.C., Gonzalez, F.J., Demierre, A. and Meyer, U.A. Proc. Natl.Acad. Sci.UEA 85, 5240-5243, 1988. 3 Meier, U.T. and Meyer, U.A; B i o c h e m i s t r y 26, 8466-8474, 1987. 4 Ged, C., Umbenauer, D.R., Bellwe, T.M., B o r k R.W., Shrivastava, P.K., Shinriki, N., Lloyd, R.S. and Guengerich, F.P. B i o c h e m i s t r y 27, 6929-6940, 1988. 5 Grant, D.M., Lottspeich, F., and Meyer, U.A. FEBS Letters 244, 203-207, 1989 Department of Pharmacology, Biocenter, Univ e r s i t y of Basel, CH-4056 Basel, Switzerland

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S 01.02

S 01.03

POLYMORPHIC DRUGOXIDATION: THERAPEUTICIMPLICATIONS Raymond L~ wPg__sle_~Y_,Heyo K. Kroemer and Lyle Siddoway Because of the usually r e l i a b l e rela{ionship between 'plasma concentration and drug action, one often assumes that patients with the d e f i c i e n t metabolism phenotype (PM) w i l l have greater drug effect than those with the extensive metabolism (EM) phenotype who eliminate the drug more r a p i d l y . Recent experience with three new and potent antiarrhythmic agents (~-encainide, ~-flecainide and~-propafenone) indicates that one cannot generalize about the consequences of polymorphic oxidation and that complete evaluation of the c l i n i c a l pharmacology of an agent is necessary for such predictions. These agents exemplify three d i f f e r e n t variations in which parent drug and metabolites can contribute to drug effects: i ) an active parent compound with inactive metabolites (flecainide), 2) metabolites with a c t i v i t y greater than parent (encainide), 3) parent and metabolites with similar antiarrhythmic potency (propafenone). I t follows that the consequences of polymorphic metabolism w i l l be d i f f e r e n t for each of these agents. Plasma level monitoring of encainide and propafenone concentrations w i l l be of limited value because of the variable presence of active metabolites. There should be a reasonably good r e l a t i o n ship between pharmacologic effects and plasma concentration of flecainide and monitoring should be of value, especially in patients with renal insufficiency. Also, the consequences of drug interactions due to i n h i b i t i o n of metabolism by agents such as quinidine should be d i f ferent for each agent and only manifest in the Er~ phenotype. Beta receptor antagonism is another p o t e n t i a l l y antiarrhythmic action of the (+)-S-isomer of propafenone. Stereo-selective clearance and polymorphic metabolism are factors which possibly contribute to the higher level of beta blockade observed in the PM phenotype after administ r a t i o n of propafenone. Consideration of the role of active metabolites, chiral factors influencing drug action and elimination, drug interactions and alterations in renal clearance may lead to better understanding of the dose-effect relationships for these and possibly many other drugs which are eliminated by polymorphically d i s t r i b u t e d metabolism. Department of Pharmacology, Georgetown University Medical Center, Washington, DC 20007, U.S.A.

Idiopathic diseases metabolising enzymes

and the polymorphic

drug -

R o b e r t L. S m i t h , D e p a r t m e n t of P h a r m a c o l o g y & Toxicology, St. Mary's Hospital Medical School, London, W2 1PG, UK. Despite the major advances t h a t have been made over the past forty years in the diagnosis and t r e a t m e n t of many of the so called idiopathic or 'spontaneous' diseases there has occurred little if any commensurate advance in our understanding of the origins of these conditions. However, the development of four concepts over the past two decades or so, w h e n considered together, perhaps reduce the seemingly intractable n a t u r e of the problem. These conceptual developments are as follows: (1) The recognition t h a t m a n y h u m a n idiopathic diseases are characterised by a high heritability component i.e. discrete genetic factors m a y be major predisposing factors. (2) The recognition in r e c e n t years of the highly polymorphic n a t u r e of the genes regulating the enzymes of xenobiotic biotransformation and in particular those concerned with the oxidative metabolic pathways. These enzymes are known to be of crucial importance in the m a i n t e n a n c e of safe homeostasis with the myriads of organic xenobiotic s u b s t a n c e s e n c o u n t e r e d i n t h e chemical e n v i r o n m e n t . Allelic modifications of t h e s e genes can be predisposing factors for morbidity a n d mortality in individuals carrying t h e m and when exposed to drugs and environmental chemicals. (3) The t h i r d factor is the now well-known observation t h a t various types of spontaneous disease cohorts display m a r k e d e n r i c h m e n t w i t h respect to the frequency of occurrence of a particular drug-metabolising phenotype. (4) Changes in the n a t u r e and incidence of idiopathic diseases a m o n g m i g r a n t peoples who move from one environment to another. These considerations arouse in a forceful m a n n e r the hypothesis t h a t m a n y idiopathic diseases arise from the interplay of genetic and environmental factors. While there has been considerable success in identifying some of the discrete genetic predisposing factors in recent years e.g. in schizophrenia, rheumatoid a r t h r i t i s there h a s been little progress with respect to identifying the possible role of e n v i r o n m e n t a l factors particularly, specific chemical agents. Posed simply, do some idiopathic diseases arise from a genetically determined inability to m e t a b o l i s e a n d h a n d l e e n v i r o n m e n t a l chemicals on a chronic basis? Identification of a n aetiological chemical agent might lead to its elimination from the e n v i r o n m e n t or alternatively to reducing or p r e v e n t i n g t h e exposure of genetically susceptible individuals to the toxic agent. Some examples of how genetic deficiencies of the drugmetabolising enzymes a n d the consequent failure to metabolise specific environmental chemicals can result in "spontaneous" disease will be discussed. These emphasize the importance of the concept t h a t m a n y such conditions reflect the outcome of the interplay of genes a n d e n v i r o n m e n t a l chemicals a n d t h a t t h i s r e a l i s a t i o n s h o u l d g a l v a n i s e a s e a r c h for s u c h substances in our environment.

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S 02.01 PREDICTIVE V A L U E OF A N I M A L E X P E R I M E N T S FOR HUMAN TERATOGENICITY. F r a n k M. S u l l i v a n All d r u g R e g u l a t o r y Authorities have requirements for r e p r o d u c t i v e toxicity testing. T h e r e is e v i d e n c e that the predictive v a l u e of a n i m a l t e s t s for e f f e c t s an f e r t i l i t y is g o o d but t h e r e is s t i l l d o u b t a b o u t t h e i r v a l u e for teratogenicity. Furthermore interest in teratogenicity is w i d e n i n g from just structural malformations s u c h as w a s s e e n w i t h t h a l i d o m i d e to i n c l u d e effects on p o s t n a t a l mental and physical development and behaviour, a n d t h i s is introducing new problems. The m e t h o d o l o g y for animal testing for t e r a t o g e n s is w e l l e s t a b l i s h e d and m o s t g u i d e l i n e s are broadly similar in p r i n c i p l e . The m a i n problem is in t h e e x t r a p o l a t i o n of the r e s u l t s between species a n d to m a n . S o m e of the important factors w h i c h h a v e to be t a k e n i n t o account in e x t r a p o l a t i n g f r o m a n i m a l s t u d i e s to m a n a r e n o w k n o w n a n d t h e s e will. be d i s c u s s e d . C h o i c e of s p e c i e s : Comparison of r e s u l t s in different species using suspect human teratogens and non-teratogens have shown that there is no o n e s p e c i e s w h i c h is c l e a r l y superior to t h e o t h e r s for a n i m a l t e s t i n g . In a r e v i e w by t h e U S A F D A for e x a m p l e it h a s b e e n s h o w n t h a t the m o u s e a n d rat s h o w the h i g h e s t incidence of positive results with known teratogens (~80%) but a l s o h a v e t h e h i g h e s t incidence of f a l s e positives with nan-teratogens. Primates on the other hand only detected a b o u t o n e t h i r d of human teratogens but p r o d u c e d very few false positives. The rabbit provided a good compromise. Mechanisms of a c t i o n : Teratology studies can provide information on t h e m e c h a n i s m s by w h i c h malformations m a y be i n d u c e d in a n i m a l s . A l t h o u g h a d i r e c t e f f e c t on t h e f e t u s is p r o b a b l y the most common, malformations may also result from actions on t h e o t h e r p a r t s of the f e t o - p l a c e n t a l unit, utero-placental b l o o d f l a w or on t h e maternal endocrine system. Knowledge of the differences between animal and human reproductive[ endocrinology a n d the p h a r m a c o d y n a m i c actions of t h e d r u g m a y i n d i c a t e whether a h a z a r d f o r h u m a n s w o u l d be e x p e c t e d or n o t . Dose effect response: Most teratologists believe that a threshold exists for teratogens b e l o w w h i c h no e f f e c t w i l l be s e e n . Thus teratogenic effects observed in a n i m a l s at h i g h d o s e s do n o t i n d i c a t e t h a t e f f e c t s w i l l a l s o be observed at l o w d o s e s . Numerous workers have t r i e d to d e v i s e f o r m u l a e for l o w d o s e r i s k assessment. M o s t of t h e s e r e l a t e t h e t e r a t o g e n i c or o t h e r r e p r o d u c t i v e t o x i c d o s e to t h e dose producing o t h e r s i g n s of t o x i c i t y is the dams. The g e n e r a l f e e l i g is t h a t the m o s t hazardous chemicals are those which produce reproductive toxic effects at d o s e s m u c h l o w e r than those producing other toxic effects. R o l e of k i n e t i c s : An i m p o r t a n t new concept in teratology is t h a t s o m e t e r a t o g e n s may act only when certain threshold l e v e l s in the m a t e r n a l b l o o d or f e t u s a r e r e a c h e d and o t h e r t e r a t o g e n s m a y be m o r e d e p e n d e n t in t h e " a r e a u n d e r the curve". Teratogenic as o p p o s e d to e m b r y o l e t h a l e f f e c t s m a y a l s o be d e p e n d e n t on t h e s e p a r a meters. W o r k on v a l p r o a t e a n d on c a f f e i n e h a v e s h o ~ n t h a t t h e s e d e p e n d on c r i t i c a l plasma l e v e l s for t h e i r t e r a t o g e n i e effects whereas cyclaphophamide m a y be a t e r a t o g e n of t h e other type. Confirmation and extension of s u c h studies w i l l be a c r i t i c a l t o o l in e x t r a polation to m a n . Department of P h a r m a c o l o g y & Toxicology, UMDS (Guy's Campus), University of L o n d o n , London, S E I 9RT.

S 02.02 A CASE-CONTROL SURVEILLANCE SYSTEM POR THE RISK ASSESSMENT OF CONGENITAL ANOMALIES A. C z e i z e l The data-set of the populatlon-based Hungarian Case-Control Surveillance of Congenital Abnormalities is described. The occurrence and distribution of drug in the so-called negative control pregnant women delivering unmalformed babies show a surprlsi~ly high intake during pregnancy. There is no big difference between the total study and negative control materials. The occurrences of true human teratogenic drugs /e.g., hydantoin/ are relatively low. Data imdicate no teratogenic effect in some suspected teratogenic drugs /e.g., all~lestrenol/. The attributable risk of drug intake during pregnancy is low, however, their teratoge~io effect is exaggerated in the clinical practice. Department of Human Genetics and Teratology . WHO Collaborating Centre for the Community Control of Hereditary Diseases, National l~stitute of H~giene, H-1966 Budapest, Gygli ut 2-6.

S 02.03 CLINICAL PHARMACOLOGY IN PREGNANCY: WHAT THE DOCTOR SHOULD DO P. C. Rubln The practising physician faces several problems in dealing with the use of drugs in pregnancy. Some drugs are known to be teratogenlc (eg phenytoin, lithium and warfarin). However, even these drugs cause fetal abnormalities in only a minority of exposures indicating that the mechanism underlying teratogenealty is complex and not simply related to the drug. There may be manyother drugs which cause fetal abnormalities in only a small percentage of exposures. Unfortunately, low grade teratogenecity in the human is very difficult to identify. In addition, considerable species variation means that teratogeneclty is also difficult to predict. The time of greatest teratogenic potential is also the time when many women do not realise they are pregnant. Organogenesis in the human is largely complete by about 56 days following conception. It is during this period that drugs can cause structural abnormalities. Even if there were a comprehensive llst of drugs which are teratogenlc in the human it would still be difficult to avoid unplanned exposure. When a woman is receiving longterm drug therapy, prepregnancy counselling is very important in order to minimlse the risks of drug induced abnormality while maximising the quality of disease control. Later in the pregnancy some drugs can cause problems (eg indomethacin and premature closure of ductus arteriosls; and the use of regular aspirin doses near the end of pregnancy causing hoemostatic problems in the neonate). I t should be remembered that pregnancy can e f f e c t drugs, as well as vice versa. Several factors can lead to decreased plasma drug concentrations. Pregnancy is associated with considerable fluid retention as well as a decrease in albumin concentration. In addition, renal plasma flow increases by about 100% towards the end of pregnancy and some metabolic pathways are probably induced. Commonly used drugs for which therapeutic drug monitoring is normally employed (eg phenytoln, aarbamazepine or theophylllne) should be monitored during pregnancy with drug doses adjusted accordingly.

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S 03.01 NONINVASIVE METHODS TO MEASURE CARDIOVASCULAR DRUG ACTIONS G.G. B e l z , K. B r e i t h a u p t , K. E r b r V. S c h r o e t e r Methods in c a r d i o v a s c u l a r clinical pharmacology Should allow: (i) t o d e t e c t d r u g e f f e c t s q u a l i tatively and to establish their haemodynamic profile, (ii) t o q u a n t i t a t e drug effects and to establish their dose-(concentration-)effect relationship, a n d (iii) t o e v a l u a t e t h e t i m e c o u r se of t h e d r u g e f f e c t s . D r u g s c a n a f f e c t v a r i o u s parameters of t h e c a r d i o v a s c u l a r system: blood pressure, cardiac output, total peripheral resis t a n c e ( w h i c h is to b e c a l c u l a t e d ) , stroke volume, heart rate, contractility, pre- and afterload, and others. We have found a spectrum of methods u s e f u l in a s s e s s i n g t h e s e haemodynamic determinants noninvasively and repetitively: the detection of f a s t a r t e r i a l w a l l m o v e m e n t s (Inf r a t o n T e n s i o m a t R) o r t h e s e r v o p l e t h y s m o m a n o m e -~ ter ( F i n a p r e s R) g i v e r e a d i n g s w e l l representative of intraarterial blood pressure. Doppler blood flow and aortic diameter can be recorded simultaneously providing a useful estimate of cardiac output (QuantascopeR). The electrical impedance cardiography ( K a r d i o - D y n a g r a p h ~) is a useful and easy to handle alternative, preferably for d e t e c t i o n o f c h a n g e s of c a r d i a c output within a -24h period. Systolic time intervals from ecg, phonocg and carotid pulse curve detect global left ventricular performance (PEP and PEP/LVET); QS=c provides valid information about contractility. M-mode echocardiography allows to estimate drug effects on preload and afterload. The available tools allow characterization of the pharmacodynamic p r o f i l e of o l d a n d n e w d r u g s in h u m a n s .

and maintaining levels of performance suitable for subsequent testing. Further, such assessments could indicate the effects of drugs on specific systems. These approaches may become more valuable in the future as information is gathered on the basic physiology of the measurements to allow appropriate interpretation of the data. Electroencephalography (EEG) has been used widely in the study of drug action in man, and much effort continues to he devoted to the understanding of the data. Prediction of therapeutic effect from the EEG remains problematical, s it is a sensitive indicator of the presence of central activity and, in this way, is complementary to behavioural measures. Indeed, the EEG can indicate the persistence of drug action in man, and can be interpreted in terms of changes in the level of arousal. Modulation of the electrical activity of the brain may one day be related to altered behaviour, but this may prove to be difficult in the absence of any corroborative evidence. However, studies on event-related potentials may provide information on more system-specific effects, particularly as far as memory and attention are concerned. The Sleep Electroencephalogram records the cyclicity of REM sleep and the continuity of non-REM sleep. Increasing knowledge of the pharmacological control of sleep will, therefore, provide insight into the central effects of drugs. Advances in understanding the control of REM sleep and the subtleties of the pharmacological modulation of nocturnal wakefulness could be used to determine the activity, and possibly indicate mode of action, of drugs acting on the central nervous system.

ZeKaPha, Zentrum fHr Kardiovaskul~re Pharmakologie GmbH, Alwinenstr. 16, 6 2 0 0 W i e s b a d e n , F.R.G.

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S 03.03

MEASUREMENT OF THE CENTRAL EFFECTS OF DRUGS IN MAN

J.R. Malagelada Abstract not received by April 30, 1989

A. N. Nicholson, Peta A. Pascoe and Nicola A. Wright Royal Air Force Institute of Aviation Medicine, Farnberough, Hampshire, United Kingdom The central effects of drugs are measured in many ways, and in this paper we consider various approaches under five headings, i.e. subjective assessments, measurement of performance, tests which detect changes in a neurological function, recordings of the electrical activity of the brain, and sleep electroencephalography. Subjective assessments are used widely in the study of d r u g action in man and they can provide useful information on changes in the level of arousal, alterations in mood and changes in performance. In some circumstances this approach may be a sensitive indicator, though in general it is wise to support such information with objective studies as the ability of an individual to assess change may itself be modified either by immediate effects or by residual sequelae. Measurement of performance has become an indispensable part of the assessment of drugs with central action. This relates to the potentially adverse effects of drugs such as hypnotics, antihistamines and antihypertensives used by the healthy and near-healthy. Many such individuals are involved in skilled work, and this is relevant to the world of transport and industry. However, though many techniques are available, it is increasingly appreciated that skills such as memory, decision making and the quality of interpersonal relationships are difficult to measure. Nevertheless, they are likely to be of significance, perhaps more so than tests of psychomotor activity. In this context, a reappraisal of our approach to the assessment of performance may be timely. Nicholson et al (continued) Tests which measure neurological functions such as tremor, eye-tracking, body sway and tendency to fall asleep during the day can be useful in those, such as the elderly, who may have difficulty in reaching

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S 04.01 B I O M E D I C A L BASIS OF S T E R E O S E L E C T I V I T Y A.H. B e c k e t t It is t w e n t y years ago since I w r o t e the article "Stereochemical Factors in Biological Activity". Until r e l a t i v e l y recently, the i m p o r t a n c e of three d i m e n s i o n s in p h a r m a c o logical actions and drug t h e r a p y has been u n d e r - e m p h a s i s e d and under-utilized. In drug m e t a b o l i s m c o n s i d e r a t i o n of t h r e e d i m e n s i o n s have p l a y e d some role but, in m y opinion, still an insufficient role. In the last few years, it seems to have been r e a l i s e d by regulatory bodies that w h e n a drug c o n t a i n s one or more chiral centres, then we are d e a l i n g with a m i x t u r e of c o m p o n e n t s w h i c h may have different biological p r o p e r t i e s and be d i s t r i b u t e d in the body and e l i m i n a t e d from the b o d y at d i f f e r e n t rates. N a t u r e operates on a t h r e e dimensional p l a n and we have ignored this aspect to our cost. The d e v e l o p m e n t of e n a n t i o s p e c i f i c bioanalysis, e s p e c i a l l y in the past decade, has facilitated probing into the kinetic aspects of the p h a r m a c o k i n e t i c s of drugs and m e t a b o l i t e s in a n i m a l s and man. The r e g u l a t o r y bodies are n o w giving active c o n s i d e r a t i o n to drugs w i t h chiral centres. However, c a u t i o n must be e x e r c i s e d to prevent u n n e c e s s a r y w o r k for the a p p r o v a l of one o s the c o m p o n e n t s of a drug w i t h a chiral centre or c e n t r e s w h e n a m i x t u r e has been g i v e n to m a n for decades. To i l l u s t r a t e the above, e x a m p l e s w i t h chiral centres w i l l be used.

of

drugs

King's C o l l e g e London, C h e l s e a Campus, M a n r e s a Road, L o n d o n SW3 6LX, England.

There are numerous examples of stereoselective hepatic biotransformafion of drugs. Whether or not stereoselective biotransformation produces alterations in the clearance of a drug may depend upon the magnitude of hepatic extraction. For a drug that is highly extracted, clearance may be rate-limited by liver blood flow. In this case, one would not expect stereoselective differences in clearance. An interesting example of a highly extracted compound is propranolol. When administered as the racemate, both enantiomers exhibit similar clearances. However, when administered separately, the S(-)enantiomer has a lower clearance. Apparently, the hemodynamic effect of the S(-)- enantiomer on hepatic blood flow reduces its clearance. For a low extraction ratio compound, differences between the enantiomers in either the plasma protein binding or the intrinsic biotransformation clearance may result in stereoselective clearance. There has been considerable interest in the stereoselective elimination of the nonsteroidal anti-infiammatory drug, ibuprofen. R(-)-ibuprofen, the inactive enantiomer, undergoes enzymatic racemization. The pharmacologic ramification of this inversion is that potency studies in vivo suggest that R(-)-ibuprofen is almost as potent as the S(+)-enantiomer whereas potency studies in vitro indicate that the S(+)-enantiomer is 100 to 200 times more potent. Stereoselective metabolism may be genetically influenced. For example, S(+)-4-hydroxydebrisoquin is produced preferentially in extensive, but not poor, metabolizers of debrisoquin. Recent studies have suggested that stereoselective renal excretion of drugs may occur. The enantiomers of the beta adrenoceptor blocking agent, pindolol, and the diastereomers, quinine and quinidine, are stereoselectively excreted. Stereoselective renal excretion may be due to stereoselectivity in either the metabolism or transport in the kidney. Stereoselective disposition has important ramifications in drug-drug interactions. First, an enantiomer may alter the disposition of the other enantiomer. Secondly, other drugs may interact with racemic compounds. Studies with warfarin have provided considerable insight into the complexities of such interactions. In conclusion, there are examples of stereoselectivity in drug absorption, distribution, metabolism and excretion. Such stereoselectivity has ramifications for rational drug therapy with racemic mixtures. To gain an appreciation of their pharmacokinetics and dynamics, racemic drug products should be treated as combination drugs, not as single entities. School of Pharmacy, University of California, San Francisco, CA,USA

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STEREOSELECTIVE DRUG DISPOSITION K.M. Giacomini Significant progress has been made in understanding the importance of stereoselectivity ha the pharmacokinetics and pharmacodynamics of racemic compounds. In this presentation specific examples of stereoselective drug absorption, distribution, metabolism and excretion will be discussed along with the relevant mechanisms responsible for the stereoselective processes. Where possible, the ramifications of stereoselectivity in drug therapy will be presented. Absorption, defined as the process by which the unchanged drug proceeds from the site of administration to the general circulation, may show stereoselectivity particularly when one considers drugs which are subject to first-pass metabolism or to facilitated transport. Notable examples are verapamil and propranolol, compounds which are highly extracted in the liver and consequently undergo pronounced first-pass metabolism. Important therapeutic consequences of this stereoselective pre-systemic metabolism on the pharmacodynamics of vempamil have been observed. Concentration-response curves are substantially different after oral and intravenous administration when response is related to plasma concentrations of racemic, but not (-)- verapamih Examples of drugs that are stereoselectively transported across the gastrointestinal membranes by facilitated systems are L-dopa and methotrexate. Distribution, which is a function of tissue binding as well as binding to plasma proteins, may be stereoselecfive. The binding of disopyramide to plasma proteins provides an interesting example of stereoselecfive plasma protein binding and its pharmacokinetic consequences. Both enantiomers of disopyramide exhibit saturable binding to plasma proteins in the therapeutic plasma concentration range. The S(+)enanfiomer binds to cq-acid giycoprotein with a higher affinity than the R(-)- enantiomer. The enanfiomers bind to the same site and therefore may displace one another. This interaction between enanfiomers has important consequences on both the volume of distribution and clearance of disopyramide. In comparison to the R(+)-enantiomer, S(-)propranolol, the more pharmacologically active enanfiomer, binds stereoselecfively to al-acid glycoprotein whereas the R(+)-enantiomer binds selectively to albumin. The binding of fimolol to specific binding sites in myocardium is stereoselecfive. The stereoselective tissue binding of fimolol may result in a longer half-life of the (-)-enanfiomer.

STEREOCHEMICAL ASPECTS OF DRUG DISPOSITION AND ACTION. THERAPEUTIC AND REGULATORY IMPLICATIONS. K. M. Williams Frequently there are both pharmacokinetic and pharmacodynamic differences between enantiomers, a reflection of the asymmetric environment of the biochemical milieu. It can only be concluded that the ideal is to administer enantiomerically pure drugs. It has been cost effective and therapeutically advantageous to do so in some cases (eg. penicillamine, dopa, levamisole) and there are data to suggest that the therapeutic index of other racemic drugs (eg. ketamine) might be significantly increased if the eutomer were employed. Choice of which enantiomer should be used is not necessarily obvious and development of the less appropriate enantiomer has occurred (eg. Stimolol for glaucoma). The rationale for the resolution of other racemates (eg. thalidomide, practolol, warfarin, ibuprofen) remains speculative and may not be cost effective. A limitation of the possibility of separating efficacy from toxicity by use of pure enantiomers is that toxicity is frequently an extension of the desired therapeutic effect of the drug. The rationale to develop an enantiomer over the racemate has not always been based on clear toxicological considerations (eg. naproxen), but even then a satisfactory cost-benefit ratio has been maintained. In exceptional instances (eg. dobutamine), the pharmacological spectrum of activity may be clinically superior for the racemate. A further therapeutic implication of enanfioselective drug disposition is that in order to understand dose or concentration-response relationships, not only should a drug and its active rnetabolites be monitored, but the active enanfiomers must also be measured for meaningful conclusions to be made. Regulatory agencies have not yet clearly formulated their attitudes to ehiral drugs. Future development will see early screening to decide which enantiomer should be developed. It may be advantageous to resolve some existing racemates especially if regulatory agencies do not require extensive preclinical studies on the enanfiomerie form. Development of achiral drugs is one approach to avoid these issues. However, the fact that chirality is integrally and inseparably an aspect of molecular geometry, means that absence of asymmetry cannot necessarily be achieved without a change in activity. Department of Clinical Pharmacology and Toxicology, St. Vincent's Hospital, Sydney, 2010, Australia.

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S 05.02

ESTIMATION ON BENEFIT E i g i l l F. Hvidberg

ESTIMATIONOF RISKSOF DRUGS:CLINICALVS PUBLICHEALTHINDICATORSFOR DECISION MAKING. L. Abenbaim. Inserm, Part% and McGill University, Montreal Four different questions are currently asked when faced with an adverse event experienced by a treated patient or a series of patients. The physician will asked: i) ~what is the chance that this event wil! occur again if I use this drug?'. The clinical epidemiologist will be interested rather in: it) 'what proportion of those events in treated patients are in fact attributable to the drug?'. A public health officer would in turn wonder: iii} "how many of such events will be avoided each year in this country if this drug is withdrawn from the market?'. All of them, and the pharmacologist and pharmaco-mpidemiologist as well, will be interested in the following: iv) 'is the adverse event actually caused by the drug?'. Question i) pertains to risk; question ill to etiologic fraction of risk in treated cases; 4uestion iii) to etiologic fraction of risk in the general population;, and question iv) to the actual relative risk, its magnitude and its biological plausibility. This questions can be answered by a subjective, qua!itativm or semiquantitative approach based on expert opinion on the one hand, or by a allquantitative methodology using epidemiological data on the other. The keyparameter is the etiologic fraction in treated cases. Not exactly in one treated case, but rather in the population of treated cases. A!gorithws have been developed toqualitativeIy assess this probability when confronted with a limited

Correctly performed, s u f f i c i e n t and c l i n i c a l l y meaningful estimation of the efficacy - starting early in the evaluation of a new drug - is a fundamental prerequisite f o r a useful assessment of the balance between benefits and risks f o r a given drug therapy. Measurements of efficacy, both in absolute terms and in p a r t i c u l a r r e l a t i v e to other therapies of the same disorder, must be carried out within the context of controlled c l i n i c a l t r i a l s . However, the estimation of the o v e r - a l l benefit of a drug goes beyond efficacy studies in the limited sense by including much wider aspects. These are related to the various consequences evoked by both the investigations themselves and by a l a t e r widespread use. The methodologies involved may, therefore, also include epidemiological studies, non-blinded multicentre investigations, and eventually meta-analyses and even retrospective case reviews. Different designs may be u t i l i z e d such as quest i o n a i r e s , q u a l i t y of l i f e studies and longitudinal observations of single or few patients. The investigational cornerstone must, however, s t i l i be the randomized c l i n i cal t r i a l , as many of the above mentioned approaches may, in f a c t , produce data of questionable r e l i a b i l i t y and q u a l i t y . The concept of Good Clinical (Research) Practice (GCP) now being widely introduced by the pharmaceutical industry as well as by national and supra-national drug regulatory authorities should, therefore, also be applied to the evaluation of benefits of drug therapies, although GCP requirements are predominantly directed towards the use in new drug applications. The problems of how to estimate the benefit of a particular drug treatment must be viewed from d i f f e r e n t angles related to who may benefit. The patient actually treated must c e r t a i n l y be the f i r s t to be evaluated, but as a l l studies of a new drug contain an inherited advantage f o r the future patients, t h i s must also be considered as a part of the t o t a l estimation. Furthermore, i t should be evaluated which implications a new drug therapy may have f o r the society at large. These could be economic or an influence on the d i s t r i b u t i o n of resources. Other consequences could be a not immediately foreseeable impact on the e n t i r e health care system (e.g. l i p i d lowering drugs) or the influence on the ecology/environment (e.g. antimicrobial drugs). Finally, i t should not be ignored that new drug investigations are s c i e n t i f i c achievements. The benefits in terms of progress in science and methodologies as well as improvement of knowledge are, therefore, important factors f o r the medical community. The estimation of benefits during drug development and in drug therapy is based on several concepts. By combining data and experience from d i f f e r e n t sources and approaches i t should be possible - f o r a given drug therapy - to establish a basis f o r a relevant, r e a l i s t i c and broadly based estimation of the b e n e f i t / r i s k balance. In turn this may lead to a more appropriate medical care policy f o r the f i e l d in question. Rigshospitalet, Clinical Pharmacology, 9 Blegdamsvej, 2100 Copenhagen, Denmark

numberof adverseevents. The bayesian approach is aimed at quantifyingthis probability within the same framework of thinking. What epideeio!ogy can do is to

provide with either the baselinerisk of a givenpathology in the contemplated populatien and the excess risk attributable to the drug (real cohort studies) or

only an approximationof the relative risk in treatedpatients via the oddsratio (case-control studies). With the baseline risk on the one hand and the relative risk or the odds ratio on the other, onecan cuepote al! the risk indicators listed above fit)to iv)]. Data from epideeio!ogical studies can of course be used for a bayesian assessment. On the other hand~ the probabilities derived from a

subjective appraisal can be of valuefor 'roughand ready' answersto questions il to iv) in a context of emergencyor crisis. It will be shown that~ whatever the magnitude of the relative risk, two parametersare only necessary for most decisions to be taken in mothcontexts: the base!inerisk of the problemand the estimation of the proportionof casesactually treated by the drug. Many questions still have to be answered by pharmacologists, epidemiologists, biostatisticiansand public health scientists, such am: I) how

should the risk be expressed?per personstreated? per year?per treatment?per inhabitants? per defineddaily doses? 2) How does the hazard function look like? ~) what 'windown of exposureshouldweconsiderfor risk assessment?

S 05.03 BALANCING BENEFITS AND RISKS: A SCIENTIFIC APPROACH TO THE ISSUES W.O. Spitzer Classically, the measurement of benefits and risks follows the following pattern: in t h e pre-marketing p h a s e of d r u g d e v e l o p m e n t the emphasis is o n m e a s u r i n g benefit, t h a t is efficacy and effectiveness with phase III randomized controlled clinical trials. Once a d r u g is m a r k e t e d , the emphasis shifts to almost an exclusive focus on risk or harm of drugs occurring after a new pharmaceutical is approved by regulatory authorities and released to the markets. This paper concentrates on scientifically admissible attempts to balance distortions in the comparison of b e n e f i t s and r i s k s of d r u g s . In t h e p r e - m a r k e t i n g phase it is n e c e s s a r y to concentrate much more on quali t y of s u r v i v a l than on length of s u r v i v a l (or surrogates of m o r t a l i t y ) by creating and validating measures of q u a l i t y of life which are rigorous and acceptable to clinicians and to the public. In t h e p o s t - m a r k e t i n g phase i t is necessary to move away from heavy dependence on evidence about harm or risk of post-marketi n g d r u g s as t h e o n l y c r i t e r i o n for retaining or banning a drug or for modifying the terms of r e f e r e n c e of i t s a p p r o v e d use in drastic ways. The newly-created Quality of L i f e (QL Index) will be presented as a reliable means of m e a s u r i n g this new dimension both in clinical trials a n d in p o s t - m a r k e t i n g surveillance. Other measures of b e n e f i t will be discussed briefly in a c o n t e x t u a l sense. A research agenda for the future will be outlined. McGill University, Department of E p i d e m i o l o g y and Biostatistics, Purvis Hall, 1020 Pine Ave. West, Montreal (Quebec) H3A IA2

A 11

S 06.01

S 06.02

CLINICAL STUDIES ON DICHROINE-B, Q I N G H A O S U AND ITS D E R I V A T I V E S Guo-Qiao Li A c c o r d i n g to the records of traditional chinese m e d i c i n e d o c u m e n t s , m o r e than 30 herbal remedies were used in t r e a t i n g m a l a r i a but m o d e r n scientific studies have proved that o n l y d l c h r o a and a r t e m i s i a are r e a l l y effective schizontocides. D i c h r o i n e - A , B and C were extracted from d i c h r o a febrifuga. Of the t h r e e , d i c h r o i n e - B is the more potent one. On t r e a t m e n t a total dose of 1 2 mg was given orally over 3 days and was sufficient to control the symptoms and clear the parasites. In terms of side-effects, v o m i t i n g was the only serious complication. In the treatment of chloroquine resistant falciparum m a l a r i a i n C h l n a , q l n g h a o s u and its d e r i v a t i v e s have been u s e d since 1979. ~olerance trials and dose findings of q i n g h a o s u suppository, artesunate and a r t e m e t h e r showed that the good t o l e r a n c e and good therapeutic dose of q i n g h a o s u suppository, artesunate and artemether were 112 mg and 56 mg/kg/5 days, 15 mg and 4.8 mg/kg/Sd, 12 mg and 9.6 m g / k g / 5 d respectively. Qinghaosu suppository in a dosage of 56 m g / k g given over 3 days in divided doses cured 555 of 358 patients with falciparum m a l a r i a and 105 patients w i t h v i v a x malaria. Two falclparum patients developed diarrhoea and changed to a l t e r n a t i v e treatment. Patients with f a l c l p a r u m m a l a r i a became afebrile in 14.9-38.9 hours and cleared parasitaemia in 35.5-52.8 h. ~he r e l a p s e rate was 45.8% in 83 patients followed for 4 weeks. In 42 severe falcipsrum malaria patients, 24 w i t h cerebral malaria, 40 patients w e r e cured and 2 died. Sodium a r t e s u n a t e given i.v. as 4.8 m g / k g in d i v i d e d doses over 3 days cured 258 and 55 falciparum and v i v a x m a l a r i a patients respectively, for f a l c i p a r u m m a l a r i a the patients became afebrile in 14.6-25.3 h and p a r a s i t a e m i a cleared in 34.1-56.4 h. Recrudescence occurred in 49.4% of 89 patients followed up. In 40 patients with cerebral malaria. 95.0% were cured with 2 deaths. Artemether given i.m. as 9.6 m g / k g in divided doses over 5 days cured all 307 f a l c i p a r u m m a l a r i a patients. T e m p e r a t u r e became normal in 21.1-29.7 h and parasites cleared in 31.9-76.2 h. Of 253 patients followed up, 6.7% relapsed. Of 27 cerebral m a l a r i a patients, 96.3% were cured and there was I death. Special studies to m e a s u r e 95% clearance time showed that this was achieved in 16 hours with artesunate, 20 h with artemether, 24 hours with q i n g h a o s u suppository, and 28 hours with i.v. quinine. S i d e - e f f e c t s of the s u p p o s i t o r y were transient and self-limlting and consisted of tenesmus (5.9%), abdominal pain (3.1%), and d i a r r h o e a (0.8%). With artemether, 8 of 76 patients (10.5%) had a l o w r e t i c u l o c y t e count on days 3-6 of treatment which returned to normal by days 7-14. No adverse r e a c t i o n s were observed in patients t r e a t e d w i t h artesunate. During the above studies, 11 patients with a h i s t o r y o f previous h a e m o l y s i s and 19 pregnant patients were treated and no adverse effects were observed.

OINSEN6 H.M. Chang T h i s r e v i e w i s based on h u n d r e d s of s c i e n t i f i c p a p e r s on g i n s e n g p u b l i s h e d w o r l d w i d e in t h e l a s t 20 y e a r s . As t h e k i n g of O r t e n t a l h e r b a l drugs since antiquity, ginseng is reputed to r e p l e n i s h v i t a l energy in biphaslc a c t i o n s to r e s t o r e normal m e t a b o l i c f u n c t i o n s and n a t u r a l b a l a n c e s , p a r t i c u l a r l y In t h e aged and d u r i n g c o n v a l e s c e n c e . BOTANY. T h e r e e r e 3 main s p e c i e s of Panax of c o m m e r c i a l

value: the root of P. glnseng is the official ginseng; P_:_. qu!nquefoilum is American ginseng; and P. notoginseng is sanql. Their chemical compositions and usages are related but different. Wild ginseng is expensive and commercial ginseng products are mainly cultivated. CHEMISTRY. Ginseng is characterized by their saponlns (glnsenosides), generally considered as the active components. From the roots and arlal parts of ginseng & congeners, at least 31 glnsenosides have been isolated and their structures identified. Thelr aglycones f a l l into 3 types: (I) protopanaxadiol, (II) protopanaxatrlol and (III) oleanollc acid. ,zl

~21

"" OOR2

The sugar moiety conslsts of glucose, arablnose, xylose & rhamnose. Ginseng may also contain giucosldes of sitosterols & stlgmasterols, polysaccharldes, polypeptldes, Zn, Cu, & Co enzymes, vitamins, volatile oils and organic acids. PHARMACOLOGY. P. ginseng is an "adaptogen" as it manifests both inhlbltory and excitatory actions on endocrine secretion and metabolism; e.g. reducing blood sugar In hyperglycemia but increasing it in hypoglycemia; enhancing pyruvate klnase activity In liver of normal rats but decreasing it in rats fed a high carbohydrate diet. The biphaslc actions may be caused by the opposite effects of individual glnsenosldes. Ginseng can activate the pltuitary-adrena] system and Increase adrenal steroids production possibly via ACTH release. Ginseng itself is not a sex hormone but it can stimulate the release of sex hormones. On the immune system, ginseng enhanced phagocytosis and nonepeclflc immunity. It promoted the natural killer cell activity and induced production of interferon and interleukln-2. Inhibitory effect of ginseng components on lipid peroxldatJon and scavenger action on free radicals may account for its anti-aging effects. Ginseng can promote both mental and physical activities and relieve fatigue; e.g.,prolong the swimming period of mice and improve the learning process of rats. IV injection of glnsenosides exhibited blphasic but predominantly hypotenslve actlon on blood pressure. The vascular effects of dlfferent glnsenosides in different animals were polymorphlc and complicated. Glnsenosides were also shown to have antl-arrhythmlc effects in rats & rabbits. Recently, ginsenosides were demonstrated to protect the heart against myocardial ischemla, infarction and reperfusion injuries in rats, rabbits and dogs. CLINICAL STUDY. Strictly controlled clinical tests on ginseng are few and most cllnleal data are derived from observations on a large population over many years. Good therapeutic results were reported in lOG cases of hypercholesterolemi a. Ginseng could reduce the dose of insulin and prolong the hypoglycemlc effect. Used In combination wlth cancer therapy, ginseng improved the quality of life of most patients. Ginseng is welltolerated when taken orally. Its acute toxicity is low but varies with individual glnsenosldes. HOwever, longterm administration and high doses may produce "Ginseng Abuse Syndrome", such as restless, insomnia, hypertension, skin eruption and morning diarrhea. CONCLUSION. Contemporary scientific studies indicate that the actions of ginseng are not simply placebo effect. More strictly controlled clinical as well as pharmacoklnetlc studies are needed. Chinese Mediclnal Material Research Centre, The Chinese University of ~ong Kong~ Shatin, Hong Kong,

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S 06.03 GUGGULIPID - THE PROMISING HYPOLIPIDEMIC AGENT FROM GUM GUGGUL (COMMIPHORA MUKUL) G.V. Satyavati

Gum guggul, renowned in the ancient Indian (Ayurvedic) System of Medicine for its use in arthritic disorders was shown to have promising hypolipidemic property (in addition to lowering the body weight), in 1966. This discovery was based on experimental and clinical studies inspired by a Sanskrit reference in Sushruta Samhita (600 BC), a well known Ayurvedic text. This was followed by nearly 40 experimental studies and clinical trials (open, controlled as also double blind) undertaken by different scientists in various laboratories and hospitals in India, over a period of two decades. The most recent clinical trial (published in 1988) reported the efficacy of gum guggul in lowering the atherogenic lipid fractions with significant rise in the HDL cholesterol in patients of hyperlipidemia. Phytochemically, several pure ketonic steroid compounds have been isolated from gum guggul. Of these, Z-guggulsterone and E-guggulsterone are mainly responsible for the hypolipidemic activity. Limited studies on the mechanism of action of the drug have reported a stimulant action of Z-guggulsterone on the thyroid. In most clinical trials, however, a standardized ethylacetate extract of the plant (containing a mixture of Z and E guggulsterones), known as guggulipid, were employed, because of a more potent action of this extract. Based on consistent work carried out at the Central Drug Research Institute, Lucknow, in 1988, a leading pharmaceutical company of India marketted the drug under the name "Guglip", each tablet containing guggulipid equivalent to 25 mg. of guggulsterones. The drug is claimed to lower serum cholesterol (by 27% ) and triglycerides (by 31% ).

given by i,v. infusion lasting I - 4 h depending on the dose, I,m, and s.c. injection cf CQ can also produoe_1 toxic plasma levels when given in doses above 5 mg kg , Lower doses are therefore given at 8 or 12 hourly intervals to achieve the some total daily dosage as with oral administration. Combinations of antimalarial drugs with different mechanisms of action are extensively used far treatment and prophylaxis. Sulphonamides and tet~ahydrofolate reductase inhibitors potentiate each other's antimalarial effect and fixed dasekge formulations of the two are widely available, T e t r a c y c l i n e or S-P i s g i v e n w i t h QN t o ensure complete p a r a s i t a l o g i c a l clearance when t h e r e i s doubt about full sensitivity to QN, It,s also generally believed that combination of one antimalarial e.g. S-P with another s.g. mefloquine could retard the development of resistance to the latter but this is still subject to proof in man. Therapeutic doses of the commonly used antimalarial drubs are usually well tolerated, Severe toxic effects like hypersensitivity skin raations~ leucapenia and ocular damage after 8--P~ amodiaquine [AQ] and CQ respectively w are associated only with long-term use. Because of this~ it is no longer advisable to prescribe S-P and AQ for prophylaXis, OQ can, but if it is taken for longer than 2 y e a r % then the patient should be monitored carefully f o r r e t i n a l changes and t h e drub withdrawn as soon as any such changes appear, Department o f Pharmacology and T h e r a p e u t i c s , University of I b a d a % Z b a d a % Nigeria.

The problems encountered in clinical trials and standardization of herbal products like gum guggul are discussed.

Indian Council of Medical R~earch, Ansari Nagar, New Delhi-110029. INDIA

S 07.01 RATIONAL USE OF ~NTIMAL.ABIAL DRUBS. L.A. Salako The rational use of drugs requires that the right drugs are used for the right indications I in the right doseLg% by the right route, for the right duration. A small variety of drugs are presently available for use in malaria. The choice of drugs in any given situation is determined by factors related to the parasit% to the drug and to the patient. The most important parasite factor is its drug sensitivity. Prominent among the drug factors are availability of apprapriate dosage form~ dosage convenient% speed of a c t i o % tolerability, safety I cast and the drug's pharmacokinatics. The important patient factors ere a g % malaria immunity status, pregnancy~ severity of the infection and presence of complications ~hat could affect the action or disposition of the drug. T h e greatest obstacle to the success of the strategy of malaria control through chemotherapy is resistance of the parasite to the currently available drugs. Resistance of P. faleipsrum (P.f.) to ohloroquine (CQ] and sulphadoxinspyrimethamine (~-P] is widespread and resistance to quinine (QN) is also increasing necessitating the use of varieties of drug combinations in many countries. Because the different plasmodial species differ in their sensitivity to drugs, the choice of drugs is determined by the causative species. In the case of P.f. the severity ef the infection is also important in the choice of drugs, Most antimalarial drugs are available in oral dosage forms and are rapidly and almost completely absorbed from the gut. The oral route is therefore prefarred~ except in the unconscious patient or in the patient who cannot tolerate the drug by this route. Paranteral at~ninistrstion cannot be justified in patients with uncomplicated malaria who can tolerate oral dosing. Recent pharmacokinetie studies on OQ and ON, the two antimalarial drugs commonly given parenterally, have made it possible to rationalise their parenteral use with respect to dose size and frequency. Both drugs are very dangerous by bolus i.v. injection and should only be

S 07.02 DRUG RESISTANCE Hagal glnsburK In spite of many years of extensive use and intensive investigations, the antimalarial mode of action of 4amlnoqufnoline containing drugs is not well understood, let alone the reasons for drug resistance. It is now generally accepted that these drugs accumulate by virtue of their weak base properties i~slde the acid food vacuole of the intraerythrocytlc malarial parasite, the organelle by means of which the parasite digests the cytosol of its host cell. Chloroquine (CQ)-susceptible parasites accumulate more drug than their drug-reslstant congeners and have a v a c u o l a r pH that is more acid than that of drug resistant parasites. Since the pH of the food vacuole is determined by an ATP-drlven proton pump acting in parallel w i t h e proton back-flttx, drug resistance could result either from reduced pump activity or/and increased ~+-efflux. Preliminary results indicate that the latter is one order of magnitude slower in CQ-sensltlve strains of Plasmodium falclparum. Unlike the lysosomotroplc effect of CQ in mammalian cells which results in the alkallnization of the intraeellular acid compartment, antimalarial drugs do not alkalinize the parasite's food vacuole at therapeutic concentrations, suggesting that they interfere with the enzymatic steps of the feeding process. Preliminary results show indeed that parasite acid phosphollpases are inhibited by the expected vacuolar concentrations of CO, quinine and mefloquine. The antimalarial action of CQ is time-dependent and becomes maximal and irreversible after 4 hrs of exposure, eoncomittant with a fraction of cellular CQ whlch cannot be removed. The llgand and affected target(s) have not been identified yet. Recent results suggest that drug resistance can be reversed by a wide spectrum of pharmacologically unrelated compounds, which are also known to reverse drug resistance in cancer cells and a similar mechanism of action has been inferred. The precise mode of action and the efficacy of drug combination in vivo remains to be established, but there is no doubt that the phenomenologlcal observations constitute a basis for a true revolution in the

A13

chemotherapy of malaria. In recent years, other chemotheraeutic approaches have been advanced, based on a deeper understanding of the physiology and biochemistry of the parasite and its interaction with the host erythrocyte. Thus, new targets such as the biosynthetic pathways of polyamines and pyrlmldlnes or hlomolecules susceptible to oxidative stress, have been identified and their inhibition by selective and relatively specific inhlbltors has been demonstrated. Nevertheless, even such novel targets are prone to become drug resistant. One possible way to circumvent s~ch evolution could be the choice of host cell targets rather than parasite ones. Such selection is based on the reasoning that variant erythroeytes, such as sickle or G6PD-defielent cells, are refractory to parasites. Generally, the blochemlstry and physiology of these red cells are widely and significantly different from those of normal cells and the probability that the parasite will evolve to adapt to the "hostile" environment provided by these cells, is close to nil. Nence, use of antimetabolltes which would mlmick the biochemical alterations found in variant red cells, should inhibit parasite development" without the eventual appearance of drug resistance. The targeting of new antimalarials into infected cells can be achieved using the recently acquired knowledge on the new permeability pathways which the parasite induces in the membrane of its host erythrocyte. These pathways are indispensable for the adequate supply of metabolites to the parasite and for the discharge of its waste products, and their blockage by bioflavonoids demonstrably leads to parasite death. Since the selectivity properties of these pathways are not matched by those of any other type of sommatlc cell, they can be used to deliver drugs specifically into malaria-infected cells, as has been shown for example for the Case of metal chelators. This approach can be further improved by the identification of parasite enzymes which could activate otherwise non-toxlc precursors of targeted drugs. Department of Biological Chemistry, Institute of Life Sciences. The Hebrew University. Jerusalem 91904, ISRAEL.

At present) %he most es regimen for treatment of m u ] t i r e s i s t a n t m a l a r i a is Q7T7. A m o r e c o n v e n i e n t r e g i m e n w o u l d be 2 tablets of 2 5 0 m g M or M S P at 6 h o u r s i n t e r v a l a n o t h e r 2 tab. at 6 h o u r s i n t e r v a l t h e n 1 tab. for p a t i e n t w i t h b o d y w e i g h t o v e r 55 or 2 t a b for o v e r 65 kg.

S 07.03

S 07.04

DRUG COMBINATIONS FOR TREATMENT AND PROPHYLAXIS OF MULTIRESISTANT MALARIA

CLINICAL EVALUATION OF MALARIA VACCINES D. St0rch.le,r Targets of P. f@,lcibarum vaccine development are preerythrocycic forms (sporozoites, liver schizonts), asexual blood forms (free merozo tes, b ood schizonts) and sexual forms (gametes, zygote). Phase I clinical evaluation is the same for the three groups of vaccine candidates, with safety and immunogenicity as the principal objectives. In the absence of surrogate measurements of protectivity, efficacy of sporozoite vaccines is determined in phase II by experimental P.~. falciparu~ infection of non-immune volunteers carried by laboratory reared Anopheles mosquitoes fed on gametocytes in culture. In this way, recombinant and synthetic sporozoite vaccines derived from the repeat portion of the circumsporozoite protein have been tested; protectivity by the two types of vaccine was 1/6 (17%, WR Ballou et al Lancet i, 1277, 1987) and 1/3 (33%, DA Herrington et al Nature 328_, 257, 1987), respectively. The procedure is safe provided that participants are reliable and knowledgeable, low levels of parasitemia are readily recognized, and a drug sensitive P. falciparum strain is used.

D. B u n n a g

and T . H a r i n a s u t a

The m o n i t o r i n g of t h e e f f i c a c y of a n t i m a l a r i a l d r u g s on f a l c i p a r u m m a l a r i a and c h e m o t h e r a p e u tic t r i a l s h a v e b e e n c a r r i e d out since 1975 at the Bangkok H o s p i t a l for T r o p i c a l Diseases. Chloroquine(C), Sulfadoxine-Pyrimethamine (SP) and quinine(Q) have cure rates which dropped f r o m 15 to 0 % in 1979 & 81, 35 to 6 % in 1979 & 80,and 94 to 73 % in 1979 & 87 respectively(l). Mefloquine (M) and the combination of Mefloquine-SulfadoxinePyrimethamine (MSP) w h i c h has an e f f i c a c y of i00 & 9 8 % in 1980 & 83 r a p i d l y d r o p p e d to 86 a n d 8 1 % in 1 9 8 5 ( 2 , 3 ) .

When t e t r a c y c l i n e l g d a i l y in 4 d i v i d e d doses for 7 d a y s was u s e d in c o m b i n a t i o n with C l.bg, SP 3 t a b l e t s a n d q u i n i n e s u l f a t e 500 mg base e v e r y 8 h o u r s for 5-7 days (Q5TT,QTTT) much h i g h e r cure r a t e s of 75 & 8 6 % in 1982 & 84, 75 & 8 6 % in 1982 & 84, 88 & 1 0 0 % in 1987 & B8 were obtained respectively (1,3). Cinchonism was frequent in the groups r e c e i v i n g Q 5 T 7 and Q T T 7 but t h e y w e r e m i l d and transient. The a d v e r s e e f f e c t s of M and M S P were also m i l d and transient and included n a u s e a and v o m i t i n g (20%) , w e a k n e s s ~ isomnia, pruritus and skin rashes, neuropsychiatric reaction (1%) and asymptomatic sinus bradycardia (30%) n o n e of w h i c h r e q u i r e d no specific treatment. Either M o r - M S P is e f f e c t i v e for prophylaxis of m a l a r i a w h e n M 1 2 5 mg weekly .~a&.~iven w i t h l o a d i n g d o s e s of 2 5 0 m g for the f i r s t 4 w e e k s . The side e f f e c t s in 2 B - d S ~ of s u b j e c t s wel-e mild and twa~sient &~d Rot significanthy d i f f e r e n t f r o m those of the p l a c e b o gYoup.

~eferences i. Bunnag,D., & Harinasuta,T. (1987). J. P a r a s i t o l 169-180. 2. H a r i n a s u t a , T . , & Bunnag,D. (1987). WHO 363-367. 3. Internal Reports 1987&1988.

Int. Bull.

Department of C l i n i c a l T r o p i c a l M e d i c i n e and B a n g k o k H o s p i t a l for T r o p i c a l D i s e a s e s , F a c u l t y of T r o p i c a l M e d i c i n e , Mahidol University,Bangkok 10400,Thailand.

S u p p o r t e d in p a r t s b y UNDP, W o r l d Bank, WHOTDR Programme and F.Hoffmann-La Roche, Switzerland.

Testing of asexual blood stage vaccines is more difficult. Intravenous challenge with infected red blood cells was performed in 13 volunteer soldiers of the Colombian military forces. In order to determine efficacy, parasitemias were allowed to build up to levels >0.5% and to persist untreated for severat days (ME Patarroyo et al Nature 332, 158, 1988). This procedure, used in the past for treatment of neurosyphilis, is not universally accepted. In the absence of WHO guidelines, alternatives for efficacy

A 14 Cont. S 07.04 testing of blood stage vaccines include: mosquito borne challenge infection in vaccinees receiwng the blood sta~e vaccine candidate plus a sporozoite vaccine e~ther in combination or in concurrent administration, or natural infection in well-defined field studies. Safety and immunogenicity, but not efficacy is required to demonstrate for vaccines against sexual forms of P. falciDarum. Sexual stage vaccines raise an ethical probleminsofar as the vaccinee does not draw immediate benefit from immunization. Hoffmann - La Roche PKFfTI, Postfach, 4002 Basel, Switzerland.

Tx it app@ars p o s s i b l e i n 60-75 % of c a s e s to achieve ~$n~le drug (SIM) maintenance therapy after 6 months. To any such schedule belongs careful monitoring of blood levels using the Sandimmun-Kit containing specific Mabs to measure unchanged drug. Using whole blood one avoids the problem of time and temperature dependency which affects plasma/serum measurements. At the same time one must remain aware of interactions which can cause increase/decrease in CS concs. In renal Tx SIM has improved graft survival by some 15-20 % in comparison with conventional therapy so that 5-year actuarial graft survival is now about 60 %. Liver and heart Tx have become routine with actuarial 5-year survival of about 60 % and 80 %, respectively, whereas heart-lung Tx still lags behind with a 2-year actuarial survival of about 60 %. Side effects are similar in all ~ndications and, apart from the general risks of I/S therapy (infection & malignancy), include reversible impairment of renal function, nephrotoxicity (with histological changes), paraesthesia, hypertrichosis, GI symptoms, gingival hyperplasia, hypertension and tremor. SIM has become established in Tx and offers great promise in a number of autoim/nune diseases where the risk/benefit ratio r e q u i r e s m o r e careful consideration. Overall, the steroid-sparing effect of SIM is probably one of its main attractions in both Tx and autoimmune diseases. Combination therapy, already used successfully in TX, may lead to still further benefits in autoimmune diseases but one has still to decide on which combination, when to use it, in what doses and for how long. SIM has achieved such widespread usage by being the prototype of a new class of I/S agents. R = Registered Trade Mark Clinical Research, Sandoz Ltd., CH-4002 Basle, Switzerland

S 08.01

S 08.02

THERAPEUTIC USE OF IMMUNOMODULATORS: SANDIMMUNR (SIM), cyclosporin) - THE FIRST iO YEARS T. Beveridge Cyclosporin (CS) is a cyclic polypeptide of mol. wt. 1203, containing ii amino acids and derived from the fungus Tolypocladium inflatum Gams. It is a potent immunosuppressive (I/S) a g e n t w h i c h , unlike traditional I/S agents, acts specifically and reversibly on lymphocytes. CS is neither cytotoxic nor myelosuppressive and has no effect on the function of phagocytic cells, ~hus preserving the host's d e f e n c e a g a i n s t infection. Whilst the exact mode of action of CS is not known its I/S effect is thought to relate to its ability to inhibit the production of interleukin-2 (IL-2) and other lymphokines (e.g. y-interferon) by actfvated T-lymphocytes (mainly T-helper cells). The inhibition of lymphokine synthesis by CS is the result of its action at the nuclear level where it prevents the transcription of mRNA for IL-2. As a result of these effects, CS is effective in both the experimental animal and man in preventing the immune response to ailoantigen following organ transplantation (Tx), and in diminishing the response to autologous antigens in autoi/amunity. In man, SIM has been used successfully in kidney, liver, heart, heart-lung, lung, pancreas, cornea, small bowel, skin and bone marrow TX. In autoin~nune diseases many clinical studies have shown that SIM is effective, so it s~ems certain that it will be used increasingly as an alternative to other I/S agents in severe cases of endogenous uveitis, rheumatoid arthritis (RA), some forms of nephrotic syndrome, severe generalised psoriasis, systemic lupus erythematosus (SLE), Crohn's disease and various other autoimmune diseases. Although it is now more than iO years since SIM was first used in clinical Tx there is still no consensus about its optimal use. The general aim is always to profit from the efficacy of SIM while using it in a way that will minimise its side effects. Thus, SIM can be given alone, along with steroids or as part of a triple or quadruple drug regimen. In renal

ihe Interferon Systom: KIRCHNER, H. Institute of Immunology and Transfusion Medicine, University of LUbeck, Med. School The interferon system is an integral part of the defense system of the body mediating a large variety of biologic effects. Presently, three groups of interferons (IFN) are kno~q: IFN ~ , IFNB and IFNaV'. IFN~ and IFNB show homolo&v on the nucleotide level of about 40-50~/~, and both IFNs bind to a COnTnonreceptor. IFN ~ and IFNB are produced after induction by leucocytes and fibroblasts. IFN ~,~ is, by definition, not only an interferon but also a lymphokine,- since i t is a product exclusively of lymphooytes. There is no homoloc~von the nucleotide level between IFN~ and IFN ~/B. Furthermere, the receptor of IFNa~ is different from tee receptor of IF-N~C/B. IFNs age defined by their antiviral activity against a large nun/oer of different viruses. The target of IFN is the cell rather than the virus itself. Through binding at the cell surface and subsequent activation of specific genes IFNs induce an antiviral state which makes cells less permissive for virus replication. The antiviral state consists of various antiviral mechanisms. /~mong the non-antiviral effects of IFNs are effects on cellular components of the immune system. Thus, one has postulated a role for interferons as inmunoregulatory molecules. Interferons augment the expression of NHC-genes of which IFN /B only affect the molecules of class I, whereas IFN affects both the molecules of class I and class II. Moreover, all IFNs increase the activity of macrophages and NK cells. Possibly, the activation of conloonentsof the inTnune system is in part responsible for the antitumer effects of interferon. In a few instances interferon is active in cancer therapy. Promissing reports have appeared on the use of IFN in hairy cell leukE~nia, Kaposi's sarcoma, non-Hodgkin's ljanphoma, and melanoma. Until now, IFN-therapy has failed to be successful for the treatment of cancers such as bronchial carcinoma, breast or colon cancer. In clinical trials, IFN therapy was useful in diseases caused by different viruses, i.e., papilloma viruses (laryngeal papillomas), herpes viruses (herpes keratitis), and hepatitis B virus.

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S 09.02

M. A. S. Moore Abstract not received by April 30, 1989

CUTANEOUS SIDE EFFECTS OF SYSTEMIC DRUGS AND THEIR MECHANISM OF ACTION J. A. A. Hunter i. Epidemiology of drug eruptions. 2. Drugs which commonly cause cutaneous reactions (include penicillins, su/phonamides, cephalosporins he_nzodiazepines, thiazide diuretics and allopurinol). 3. Drugs which very rarely cause cutaneous reactions (include digoxin, potassium and iron preparations and vitamins). 4. Classification, mechanisms and some examples of

drug eruptions: Non-immunological a)

b)

reactions (more than 80% of drug eruptions) Direct toxic reactions Overdosage: blisters~barbiturates Predictable side effect: alopec_ia/cytotoxic drugs Idiosyncratic (qualitatively abnormal respons~ variegate porphyria/oestrogens Intolerance (exaggerated normal response): haemorrhage/methotrexate Phototoxicity: exaggerated sunburn reaction/ thiazidediuretics Accumulation: pigmentation/chlorpromazine Tumour induction: arsenic/skin malignancies

Indirect toxic reactions Release of inflammatory mediators: aspirin/ urticaria Exacerbation of skin disease: psoriasis/ B-blockers Drug interactions: haemorrhage/methotrexateaspirin Ecological imbalance: dermatophyte infections/ steroids Tumour induction: azathioprine/HPV-squamous cell

carcinoma

S 09.01 QUANTIFICATION IN DERMATOPHARMACOLC~ H. I. Maibach In recent decades many advances in dermatopharmacology evolved as "spin-offs" of development in general pharmacology with structural or delivery system modifications for Skin (e.g., corticoids, antifungals, 5FU, antibacterials and pesticides). At least one resulted from an individual scientist's conceptual curiosity (isotretinoin). The skin presents a variegated, puzzling, complex yet fascinating opportunity to perform quantitative bioassays that might yield new pharmacologic agents. This presentation will describe the mentation and technology involved. Examples will include: corticoid perturbations in protein formation, retinoid alterations in hyaluranate accumulation, skin blood flow related to hair growth and delivery of drugs into skin rather than through skin.

Immunolc~ical reactions (the great minority) ~ype I: Anaphylactic type - igE mediated: urticaria/ penicillin Type III: Arthus type - circulating immune complexes: vasculitis/thiazide diuretics Type IV: Delayed type hypersensitivity lymphocyte mediated: eczematous rashes/ penicillins 5. Some characteristic (but not specific) eruptions Pemphigus-like: D-penicillamine Psoriasiform: Practolol Lichenoid: Gold Photosensitive-bullous: Nal• Acid Multiple skin tumours: Arsenic Erythema multiforme: Sulphonamides Fixed drug eruption: Phenolphthalein Anqioedema: AsPirin Maculopapular rash: Ampieillin/infectious mononucleosis Skin necrosis: Warfarin Lupus erythematous-like: Bydralazine Toxic epidermal necrolysis: Phenylbutazone Mypertrichosis: Minoxidil 6. Diagnosis a) History: Temporal relationship b~ Discontinuation of drug: Flaws and drawbacks c) Provocation with drug: Ethical considerations d) Skin tests: Patch and prick testing e) In vitro tests: RAST: Basophil d~ranulation test. Lymphocyte transformation test 7. Useful References Bork K: Cutaneous side effects of drugs. W.B. Saunders Company, Philadelphia 1988. Bruinsma W: A guide to drug eruptions. 4th Edition 1987. University Department of Dcrmato/c~qy, qhe Royal infirmary, Edinburgh EH3 9YW Scot/and.

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S 10.01

S 09.03 DRUGS AND THEIR A C I I O N

ON THE EYE

O. Hockwin~ U. M ~ l l e r - B r e i t e n k a m p and A. Wegener The eye is an highly s p e c i a l i z e d , very s e n s i t i v e and well o r g a n i z e d organ of sense~ r e a c t i n g immed i a t e l y to s t r u c t u r a l and f u n c t i o n a l d i s t u r b a n ces, r e a l i z e d by the p a t i e n t as s u b j e c t i v e visual i m p a i r m e n t . The eye r e p r e s e n t s a c o m b i n a t i o n of nearly all kinds of tissue s t r u c t u r e s like s t r i a t e d and smooth muscles, sinews, s e c r e t i o n organs, p e r m e a b l e and s e m i - p e r m e a b E e m e m b r a n e s as well as p r o n o u n c e d p i g m e n t layers. B e s i d e s tissues with a high blood supply like retina and c h o r o i d e a it c o n t a i n s c o m p a r t m e n t s w i t h o u t direct c o n n e c t i o n to b l o o d (and nerve) s y s t e m where e x c h a n g e of matter is c o n t r o l l e d by blood b a r r i e r functions. As the only organ of the body it has in order to fulfill its main ruction - tissues and fluids with t r a n s m i s s i o n of the v i s b i l e light. The m a i n t e n a n c e of the t r a n s p a r e n c y is based on normal m e t a b o l i c c o n d i t i o n s . A n a t o m y and function of the entire eye allow direct e x a m i n a t i o n by n o n - i n v a s i v e m e t h o d s and d e s c r i p t i o n / d o c u m e n t a t i o n of p a t h o l o g i c changes in m o r p h o l o g y . Last not least, the p a i r w i s e a r r a n g e m e n t of the eyes allow direct c o m p a r i s o n ( b i o l o g i c a l twins) of t r e a t e d with u n t r e a t e d control eye in p h a r m a c o k i n e t i c a l and t o x i c o l o gical s t u d i e s i n - v i t r o as well as in-vivo. In a n a l y s i n g the m a n i f e s t a t i o n of d r u g - i n d u c e d c h a n g e s or d i s e a s e s of the eye we have to d i f f e r e n t i a t e b e t w e e n i. local side e f f e c t s after topical a p p l i c a t i o n of o p h t h a l m i c drugs, 2. local side e f f e c t s after s y s t e m i c a p p l i c a t i o n of drugs (mostly n o n - o p h t h a l m i c s ) as well as 3. s y s t e m i c side effects after topical a p p l i c a t i o n of o p h t h a l m i c drugs. Based on c l i n i c a l o b s e r v a t i o n s and e x p e r i m e n t a l results, d e t a i l e d l i t e r a t u r e reviews and m o n o g r a p h i e s c o v e r i n g a great number of d r u g - i n d u c e d ocular c h a n g e s are now available. E x a m i n a t i o n s of ocular t o x i c o l o g y in c h r o n i c drug t o x i c i t y s t u d i e s have not yet r e a c h e d the s t a n d a r d w h i c h is in a c c o r d a n c e with the present k n o w l e d g e of o p h t h a l m i c science. Main p r o b l e m s arise by the use of n o n - p i g m e n t e d (albino) animals. E v a l u a t i o n s with respect to the (pigmented) human eye are almost i m p o s s i b l e . There is still nearly a c o m p l e t e lack of ocular p h a r m a c o k i n e t i c m e a s u r e m e n t s . Such d i s t r i b u t i o n studies have to be i n t r o d u c e d at least for all drugs of i n t e n d e d longer t h e r a p e u t i c a l a p p l i c a tion. For d o c u m e n t a t i o n i n s t r u m e n t s with i n t e g r a t e d photo e q u i p m e n t (photo s l i t - l a m p , fundus camera, S c h e i m p f l u g photo system) should be used. For s p e c i a l p r o b l e m s a v a r i e t y of m e t h o d s may be applied. - A t t e n t i o n must be payed to m u l t i f a c t o r i a l origin of lens o p a c i f i c a t i o n in human of old age. A c o i n c i d e n c e of several factors - among them d r u g s - which need not be d i r e c t l y c a t a r a c t o g e n i c , but may act as s u b l i m i n a l (or p r o m o t i n g ) factors, r e q u e s t a special test p r o c e d u r e . Animal models to test the c o c a t a r a c t o g e n i c p o t e n t i a l of drugs are now available. The h i a t o p a t h o l o g y of the lens does not c o n t r i b u t e at all to e l a b o r a t e the s u b l i m i n a l d a m a g i n g m e c h a n i s m , it is almost o b s o l e t e as an i n d i c a t o r and should not longer be r e q u e s t e d by g o v e r n m e n t a l drug offices. It should be replaced, w h e r e n e c e s s a r y , with p o s t - m o r t e m a n a l y s e s of b i o c h e m i c a l lens p a f a m e t e r s being a more s e n s i t i v e i n d i c a t o r even for s u b l i m i n a l e f f e c t s which did not yet affect the lens t r a n s p a r e n c y . M e t h o d s and e x p e r i e n c e s are today a v a i l a b l e that the eye needs no longer to be among the n e g l e c t e d o r g a n s of drug r e s e a r c h and their c l i n i c a l a p p l i c a t i o n . A b t e i l u n g f~r e x p e r i m e n t e l l e O p h t h a l m o l o g i e der U n i v e r s i t ~ t Bonn, S i g m u n d - F r e u d - S t r . 25, D-5300 BONN 1

THERAPEUTIC STRATEGIES A N D GOALS R. Gugler Healing of acute gastric and duodenal ulceration is achieved with a variety of different drugs representing three major mechanisms of action: acid neutralization, inhibition of acid secretion, mucosal protection. Most drugs heal 70 to 90 % of ulcers within four weeks with some variation in the 2 week healing rates. Symptom relief is seen within one week in the majority of patients. Of all factors "which might influence individual ulcer healing only smoking has been uniformly identified to be associated with the incidence of duodenal ulcer and a delay in ulcer healing, while age, ulcer history or socio-economic factors play a role only in some studies.Antacid therapy is found to be effective even in small dosis of 200 mmol neutralization capacity per day suggesting that effects other than acid neutralization are present such as mucosal procetion. H2-receptor antagonists to date dominate the peptic ulcer treatment, whereas the clinical significance of longer and more effective acid inhibition by H / K - A T P a s e inhibitors remains to be established. The prostaglandins might find their place in the treatment and prophylaxis of lesions caused by nonsteroidal antiinflammatory drugs rather than in common ulcer therapy. As 25 % of duodenal ulcer patients have 2 or more ulcers per year, definition of strategies to treat the chronic ulcer is the primary challenge today. Prevention of ulcer relapse and of ulcer complication are the goals in chronic treatment. Intermittent treatment is designed to give the patient a full course of therapy for any new ulcer. With this strategy the incidence of complications (perforation, bleeding, stenosis) is not reduced as shown by a constant rate of ulcer surgery. Long term prophylaxis by H2-receptor antagonists effectively reduces ulcer relapse rates, but does not chance the natural history of the disease as seen by high relapse rates after stopping maintenance treatment. Ulcer surgery is performed less frequently today in the presence of potent drugs which have a minimum of side effects. Even after highly selective vagotomy ulcer relapse rates of up to 2o % over 5 years show that the disease is not cured by the operation. For the duodenal ulcer patient with a high relapse rate in a given time maintenance treatment is the recommended strategy, but surgery is necessary in treatment failure, in the case of complications or if the patient is noncompliant to the medical treatment.

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S 10.02 USE OF INHIBITORS OF ACID SECRETION IN ULCER THERAPY A.L. Blum S e c r e t o r y inhibitors are used both in gastric ulcer and in duodenal ulcer, in the former in spite of normal or low acid secretion and, in the latter, in spite of an important pathophysiological role of C a m p y l o b a c t e r pylori. Thus, the basic idea of secretory inhibition is not to normalize e l e v a t e d acid secretion but to shift the balance of multipte pathophysiological factors in favor of repair of the present ulcer and protection from the next attack. The clinical effectiveness of acid inhibitors is proportional to their reduction of acid secretion; nocturnal inhibition appears to be more important than inhibition during the day. The strongest presently known secretory inhibitor, omeprazole, yields the best healing rates. At present, two differing views are expressed: t r a d i t i o n a l i s t s s e t t l e for the inferior healing r a t e of histamine H2 antagonists to avoid h y p e r g a s t r i n e m i a and its consequences at all costs; in contrast, maximalists think that the drug which yiehls the _fastest healing rates is the best, Histamine H2 antagonists are given once a day; a theoretical advantage o[ giving them w i t h dinner, instead of late in the evening, is not c l i n i c a l l y relevant. In order to assess to optimal length of t r e a t m e n t , we performed a prospective study in 2109 patients w i t h duodenal ulcer t r e a t e d with ranitidine. Healing was delayed in patients with smoking, large ulcers, m u l t i p l e ulcers, a history of slow healing and complications and in those who were unemployed. When more than two of these risk factors are present, t r e a t m e n t should last for more than # weeks. Maintenance t r e a t m e n t with secretory inhibitors markedly decreases the recurrence rate. Risk factors indicating t h a t recurrences may occur in spite of maintenance t r e a t m e n t are heavy physical work, psychological stress, smoking, duodenitis, persisting pain a f t e r healing, m u l t i p l e ulcers, a long ulcer history and certain geographical factors such as a habitat in the northern part of Germany. Gastroenterologie, CHUV, C H 1 0 l l Lausanne

Some antiulcer drugs, which are believed to act primarily by neutralization of gastric acid (antacids) or by coating the mucosa (Sucralfate, Oe-Nol), have been reported to exhibit gastroprotective properties both in animals and humans against various irritants (aspirin-like drugs, bile acids, ethanol or stress) partly due to the stimulation of mucosal production of PG. Although there is little doubt that PG, especially their stable methylated analogs and drugs such sucralfate or Oe-Nol exhibit remarkable gastroprotective properties, it is not clear whether such protection could offer any clinical benefit in the therapy of peptic ulcer and whether gastro-protective drugs are superior to ulcer healing properties of "classic" antiulcer gastric inhibitory agents such as H2-receptor antagonists or anticholinergics. Recent clinical trials with various methylated PGE analogs revealed that these agents are capable to enhance ulcer healing but only when used in gastric inhibitory doses. In contrast, cytoprotective doses did not affect significantly the healing rate suggesting that cytoprotective properties, which are so dramatic in prevention of acute mucosal damage play little role in ulcer healing. This indicates that the inhibition of acid secretion rather than strengthening of mucosal defence mechanisms plays an important role in promotion of ulcer healing. Positive effects in ulcer healing obtained with sucralfate or De-No] (which do not affect gastric acid secretion) could probably be attributed to the formation by these drugs of physical barrier over ulcerated mucosa to prevent acid-pepsin aggression and to the accumulation in the ulcer area of epidermal growth factor (EGF) which may promote the process of ulcer healing. Institute of Physiology, Medical Academy, ul. Grzegorzecka 16, 31-531 Krakow, Poland.

S 10.03

S 11,01

CYTOPROTECTI~4 S.J. Konturek Gastric mucosa is constantly exposed to various irritants but it usually maintains its integrity due to several lines of defence including mucus-alkaline secretion~ mucosal hyrophobicity, rich mucosal blood flow, stabilization of tissue lysosomes, maintenance of mucosal sulfhydryls and rapid proliferation and renewal of mucosal cells. Prostaglandins (PG) prevent acute gastric mucosal damage and ulcerations induced by a wide variety of agents, hence PG have been originally proposed to contribute to the overall protective process ("direct" cytoprotection) by activation of various mucosal defence lines, particularly, bY prevention of vasocongestion, ischemia and deep hemorrhagic necrosis. The relation between t i s s u e PG g e n e r a t i o n and mucosal p r o t e c t i o n does not appear to be c l o s e l y r e l a t e d and p r o b a b l y only minute amounts of PG are required to maintain mucosal integrity. In contrast to PG, other products of arachidonate metabolism such as TxA2, LTC4 or LTD4 and the related lipid, platelet activating factor (PAF), appear to mediate mucosal damage mainly by the disturbance in mucosal microcircu]ation and tissue ischemia. Gastroprctection can be achieved by stimulation of mucosa] biosynthesis of protective PG or by the inhibition of the release or action of the proulcerogenic arachidonate metabolites. Certain natural substances such as sulfhydryls, epidermal growth factor or po]yamines protect the mucosa via PG-independent mechanism probably by enhancing the tissue repair processes. The resistance of mucosa to injury can be also increased by challenging with mild irritants ("adaptive cytoprotection") and this has been attributed to the stimulation of mucosal PG biosYnthesie but certain role may also be played by physical barrier formed from the alkaline mucoid debris ("mucoid cap") which mitigates the effects of subsequent exposure to the necrotizing agents and allows for rapid epithelial repair and reconstitution.

PRENATAL DRUG TREATMENT. P. VERT

The rapid progress in antenatal diagnosis of an increasing number of diseases and the understanding of some principles of drug transfer across the placenta led to more or less successful attempts of prenatal treatment which remain partly empirical. The bidirectional kinetics through the placenta, volume of distribution, free fractions, metabolism, Te ~ in the fetal compartment are still poorly documented, with increased risks of either inefficacy or toxic effects. The maternofetal ratio of a drug plasma level at a given time (ie birth) does'nt allow extensive conclusions~ Glueocorticoids particularly betamethasone have been widely used to enhance lung maturation and surfactant production by the alveolar type II cells, between 28 and 32 weeks of gestation with controversial results in male infants, Dexamethasone has been successfully prescribed for the prevention of virilization of female fetuses at risk of adrenogenital syndrome due. to 21hydroxylase deficiency. Sustained supraventricular tachycardia, often associated with hydrops fetalis, both diagnosed by sonograph~ has been converted by different drugs : Digoxin, Betablowers (Propanolol), Proeainamide, Calcium channels blockers (Verapamil). Amiodarone containing substantial amounts of iodine may induce a fetal hypothyroidism. Congenital toxoplasmosis can be diagnosed by fetal cord blood sampling. Prenatal treatment with spiramycine is largely used with good beneficial evidences. The sdjunction of Pyrimethamine and Sulfadiazine has recently been proposed. Prenatal treatment has to be considered in the context of fetal development and viability and in a pluridisciplinary approach. Waiting for more knowledge in antenatal pharmacology, the evaluation of benefits and risks must challenge audacity in desperate diseases. Maternit~ R@gionale Universitaire et INSERM U 2?2 54042 Nancy France.

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S 11.02 ANALGESICS IN NEWBORNS? L.O. Bor6us Pain is subjective and our knowledge about it is related to our own experience and interpretation of the stories that others have told. In the newborn infant, a verbal or Other type of symbolic language for the description of the type and intensity of pain cannot be obtained. This does not mean that a cognitive part of the pain in the infant must be missing. But in order to assess pain the observer must resort to interpretation of behavioural or biochemical events following what we believe to be painful stimuli. Motor responses such as facial expression, crying or special leg/ann movements have been interpreted as manifestations of pain in the newborn and scales for quantitative assessment of these reactions have been presented. Alternatively, metabolic, hormonal, or neurophysiological changes that follow nociceptive stimulation have been determined. The basic methodological difficulty is that even if the most sophisticated technique is used in these measurements, the investigator will lack the final proof of the existence of cognitive pain which is the selfreport from the patient. Recent studies in the area suggest that proper analgesia is of advantage to the newborn. Adequate anaesthesia during surgical interventions lightens the stress load on the infant and improves the postoperative course. Thus, pain itself may be harmful and treatment with analgesics may be a more important factor for the results of neonatal care than earlier realized. Remarkably few studies have been made on the usefulnes of analgesics in the newborn. It appears that the methodological difficulties to measure pain and pain relief in this age period is not the only reason. Lack of interest in the problem is also evident. Many procedures that would be inconceivable in the adult without pain alleviation are still often routine in the newborn. Recent reviews have shown that many paediawic anaesthetists have long been reluctant to prescribe analgesics to newborns. The conception that the newborn cannot feel pain is impossible to prove or disprove, Both nociceptive and anti-nociceptive systems are working in the central nervous system and neurological immaturity itself does not necessarily imply that pain cannot be suffered. The negative biochemical and behavioural consequences of nociceptive stimulation are the only signals from the patient for improved pain relief and should be reasons enough to provide the newborn infant with analgesia. Several routine procedures in neonatology are associated with iatrogenic nociceptive stimulation: injections, sampling of body fluids, application of catheters, etc. Birth traumata and postnatal surgery are also causing pain. These situations must be identified and as much as possible avoided. In some cases old routines may even be entirely abolished. One example is the application in the eye of silver nitrate in the prophylaxis of neonatal ophthalmia. Both paracetamol (acetaminophen) and opiates may be useful as analgesics in the newborn. The deficient neonatal glucuronidation of paracetamol is no problem and is compensated by efficient sulphate conjugation. The reluctance to use opiates in more severe pain may be questioned, Data on the pharrnacokinetics and effects of opiates in the perinatal age are scarse but can be obtained from studies where these drugs are given as analgesics to the mother during labor. The routine use of opiates such as pethidine (meperidine) for labor pain may give rise to analgesia also in the fetus and newborn. If this represents a risk or a benefit to the child after birth remains to be assessed. Department of Clinical Pharmacology, Karolinska Hospital, S-10401 Stockholm, Sweden

S 11.03 BENEFIT-RISK EVALUATION OF TOCOLYTIC TREATMENT Marc J.N.C. Keirse Surveys among obstetricians in several countries indicate that there is much uncertainty about the effects tocolytic drug treatment for the prevention and treatment of preterm labour. Enthusiasm for tocolytic treatment~ has paled because of improved neonatal care, maternal complications of the drugs, and realization that their widespread use has not reduced the overall incidence of preterm birth. Yet, prevention of preterm birth as leading cause of perinatal mortality, morbidity, and long-term handicap, remains a high priority. Uncertainty about the effects of tocolysis relates to the nature of preterm labour and of preterm birth, to confusion between substantive and surrogate outcomes of treatment, and to the paucity of adequately controlled data to judge these effects. Successful inhibition of labour depends on early diagnosis, but early diagnosis is so inaccurate as to lead to success rates that are unrealistically high. Many agents have never been evaluated in any other manner. Those that have been evaluated have been assessed more in terms of arrest of contractions and delay of delivery than in terms of whether mother and baby are any better with than without the treatment. To address these uncertainties formal overviews (meta-analyses) were conducted of all controlled trials of any agent used to either prevent or inhibit preterm labour. Agents on which evidence was sought have included progestational agents, magnesium sulphate, relaxin, ethanol, betamimetic agents, prostaglandin synthesis inhibitors, calcium antagonists, erythromycin, diazoxide and oxytocin analogues. Only 3 categories of agents have been evaluated to any significant extent for tocolysis in active preterm labour: ethanol, betamimetics and prostaglandin synthesis inhibitors. The data on ethanol derived from 2 placebo-controlled trials, 5 randomized comparisons with betamimetic agents, and other studies indicate that ethanol should be entirely abandoned for preterm labour. Only 3 of the many betamimetic agents have been evaluated against placebo or no treatment (ritodrine, terbutaline and isoxsuprine). Results from these studies (n=12) indicate that betamimetics can arrest labour, delay delivery, prolong gestation, and reduce the incidence of preterm birth. These effects have so far not been matched by a statistically significant decrease in mortality or severe morbidity of the infant. Trials on the prophylactic administration outside active labour have shown no influence on the incidence of preterm birth, although maintenance treatment (after acute preterm labour) appears to reduce the incidence of recurrence of preterm labour. Few controlled evaluations of prostaglandin synthesis inhibitors have been conducted; all dealt with indomethacin and none were truly placebo-controlled. The data indicate arrest of contractions, delay of delivery, and a reduced frequency of preterm birth and low birthweight. No benefits were detected in infant mortality or morbidity. Wide differences among agents that inhibit prostaglandin synthesis do not justify extrapolation of effects from one agent to another. Departments of Obstetrics of the Universities of Leiden, The Netherlands, and Leuven, Belgium. PO Box 9600, 2300 RC Leiden, The Netherlands.

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S 1,2.02

PHARMACOLOGIC STRATEGIES FOR THE TREATMENT OF ALCOHOL ABUSE AND DEPENDENCE E.M. Sellers The development of new pharmacologic treatments depends on our understanding of the neurobiologic regulation of ethanol intake. The acquisition, maintenance and cessation of alcohol drinking are regulated in different ways. Currently, attention has focussed on the roles of serotonin and dopamine. Drugs could decrease alcohol consumption by modifying the positive or negative reinforcing actions of ethanol; produce a direct or conditioned aversive reaction; decrease the desire to drink; modify mood states or fuctuation that led to drinking; suppress target symptoms, e.g. anxiety, depression, that may prompt or sustain drinking; enhance the learning of behavioural self-management techniques; produce side effects which make drinking less attractive, e.g. nausea, Clinical features of alcohol abuse and dependence suggest a variety of drug strategies are needed or may be effective. Screening of compounds for effects on alcohol consumption is uncommon. A sensitive (< 0.1 ml) high resolution (< t rain) real time confnuous volumetric monitoring system offers new possibilities for pre-clinical detection of effects on micro4:lrinking patterns and importantly in low dependence drinking. Drug effects with serotonin uptake inhibitors can be demonstrated at doses 20- to 50-fold lower than before. At low doses these drugs decrease bout initiation and bout number, but not the size of ethanol drinking bout. GR38032F, a 5-HT 3 antagonist, decreases alcohol consumption in rats at doses of only 0.01-O.1 ~g/kg in this system. Important evolving clinical methodologic issues include: specification of outcome with respect to alcohol (e.g. reduction to safe levels or abstinence) or other measures (e.g. psychosocial consequences); accurate identification of the treatment population; valid and reliable measurement of alcohol consumption; pharmacokinetic appropriateness; incorporation of compliance measures; stratification with respect to severity of problem; characterization of mood states; lifetime and current mental disorders; concurrent other drug use; specification and control of the form and extent of concurrent non.rug therapy; and duration of drug therapy. Regulatory guidelines in this area could help_ Separation among drug treatments for acute detoxication (withdrawal); initiation of reduced alcohol use and maintenance of a lowered alcohol use is of conceptual, strategic and practical importance. Acute withdrawal is readily treated by diazepam loading or equivalent. With respect to initiation of a decrease in use, serotonin uptake inhibitors consistently decrease alcohol consumption and preference in rat drinking models, e.g. citalopram, viqualine, zimelidine, fluvoxamine, sertraline, indalpine and fluoxetine. Four separate randomized double-blind clinical trials (3 cross-over, 1 parallel design) of treatment initiation in heavy social drinkers not seeking treatment (average daily ethanol consumption 95 g) have reported decreases in drinking (mean %): zimelidine 200 mg 9.3% (p < 0.05); citalopram 40 mg 9.1% (p < 0.05); viqualine 200 mg 17.1% (p < 0.05) and fluoxetine 60 mg 16.6% (p < 0.01) with 2 4 weeks of drug treatment. On average the magnitude of response is relatively modest, but the drugs were not given in conjunction with other psychosocial interventions which could maximize the effect. These drugs also decrease body weight (range 0.8 to 2.2 kg over 4 weeks) but do not affect smoking. There are several problems with the agents currently used to maintain nonproblem levels of alcohol intake (e.g. disulfiram). For example, the long-term effects of disulfiram are small, appropriate only to an abstinence goal, and are based on non-pharmacologic actions (vis. expectancy). Lithium significantly reduces relapse among depressed alcoholics; can decrease the need for hospitalization and among compliant non-depressed male alcoholics with serum lithium (> 0.4 mEq/I) significantly improved abstinence at one year (67% vs 44%). No drug has been shown to importantly maintain non-problematic levels of alcohol use on a pharmacologic basis for long periods of time. A variety of other CNS active compounds are active in animal models of ethanol drinking or in decreasing appetitive behaviours, e.g. angiotensin converting enzyme inhibitors; benzodiazepine inverse agonists; calcium channel antagonists; 5-HT1A agonists; opiate antagonists; monoamine oxidase inhibitors; 5-HT$ antagonists; eholecystokinin; and dopamine antagonists. All are potential leads for clinical studies. The high relapse rate of alcohol dependence disorders suggest that initiation of a treatment response (a decrease of alcohol use) and its maintenance are both important. Strategies to achieve a sustained drug effect will likely require combination with behavioural self-management techniques, e.g. selfmonitoring; goal selection; functional analysis of drinking; cognitive restructuring; development of coping strategies. Combining innovative pharmacological and behavioural interventions show considerable promise in the initiation and Iong-terrn treatment of alcohol abuse and dependence. Clinical Psychopharmacology Program, Addiction Research Foundation and Departments of Pharmacology and Medicine, University of Toronto, 33 Russell Street, Toronto, Ontario M5S 2S1, Canada.

TREAT~2~ OF NICOTINE DEPENDENCE M.A.H.Russell Smoking is a drug-taking activity. Most smokers absorb sufficient nicotine to obtain pharmacological effects and to develop dependence. Nicotine can act as a primary reinforcer in animals. It influences mood and performance in humans, induces tolerance, and physical as well as psychological changes occur on withdrawal. Chronic exposure to nicotine induces an increase in the number of nicotinic cholinergic receptors in many parts of the brain indicating the presence of structural as well as function -al changes in the central nervous system which may play some part in the difficulties of giving up smoking. One way to ease these difficulties is to provide nicotine from an alternative and less harmful source. Nicotine polacrilex gum used as an aid to smoking cessation has been shown to alleviate withdrawal symptoms and approximately double the success rates achieved by placebo gum or behavioural methods alone. Its limitations and the potential of other forms of nicotine replacement will be discussed, including a nicotine nasal spray, nicotine skin patches and a cigares plastic device which delivers smoke-free nicotine vapour. The rationale and potential of other pharmacological aids such as clonidine, naltre• and nicotinic blockade with mecamylamine will be briefly discussed.

S 12.03 TREATMENT OF OPIOID DEPENDENCE C.P. O'Brien Pharmacological strategies are useful at each phase of treatment; diagnosis, detoxification, maintenance and relapse-prevention. Diagnosis of physical dependence can be assisted by the use of the short acting opioid antagonist, naIoxone. For detoxifieation, a long acting agonist such as methadone can be used in gradually decreasing dose to ease the symptoms of withdrawal. An alternative is clonidine, a centrally acting alpha 2nonadrenergie agonist which decreases presynaptic noradrenalln. Clonidine diminishes the autonomic aspects of the opioid withdrawal syndrome although some discomfort remains. Repeated failures at remain;ng abstinent can justify the use of methadone as a maintenance treatment. The patient's craving for opioids is relieved and the methadone produces cross tolerance to other opioids thus diminishing their ability to produce pleasure. Methadone has been successful with large popu]ations in the US. The specific opioid antagonist, naltrexone, can be used to prevent relapse in drug-free former opioid addicts. Naltrexone is active at opiate receptors as a competitive inhibitor for up to three days. Abstinent patients who receive naltrexone are thus prevented from impulsively resuming opioid use. In practice, antagonist treatment works best with well-motivated intelligent patients. The partial agonist-antagonlst burprenorphine holds promise because its agonist properties make it more rewarding than naltrexone, and thus more popular with prospective patients. U of Pennsylvania/VA Med Ctr, 3910 Chestnut St./6178 Philadelphia, PA 19104 USA

A 20

S 13.01 SELECTIVITY

OF CALCIUM-ANTAgONISTS

M. Spedding The selectivity their clinical

of calcium-antagonists spectra

the calcium channels sites.

available

may be classed

The calcium-antagonists

dihydropyridines vasodilators; verapamil

into several

for L channels protonateable

and diltiazem

allosterically

for L channels

effects.

As the sodium channel calcium

affinity

class

channel

is inaccessible

selectivity effects

which

resembling

such effects

the

III drugs have equivalent channel

and

in heart and smooth muscle activator

Bay K 8644 Selective

are

indicating

or that they trap

may have clinical

In this respect,

accumulate

during

those of Bay K 8644;

may explain

it in

antagonism

utility

if

acyl carnitines

ischaemia

selective

dependent

Thus,

the clinical

are

and have

antagonism

some of the anti-lschaemic

certain calcium-antagonists. drugs will be highly

homology

oral or interperitoneal treatment with nimodipine in rats bearing a lesion in the sciatic nerve. Age-related deficits in the walking pattern of freely moving rats could be suppressed or delayed by subchronic treatment with nimodipine. In addition, such nimodipine treated rats showed better conduction velocities in the various peripheral nerves tested and a higher fibre density in cross sections of their sciatic nerves. In addition nim~dipine blocks the age-related changes in Ca 2fluxes in rat hippocampal neurons. Besides its antiischemic activity and its beneficial effects on functional deficits that relate to neuronal plasticity, nimodipine was shown to have anticonvulsant activity in mice, rats and rabbits. Nimodipine was considerably more potent than phenytoin in the treatment of electreconvulsive seizures in rabbits. Thus, the therapeutic usefulness of nimodipine in diseases of the nervous system appears not to be limited to cerebral ischemia, but may also include age-related degenerative diseases and epilepsy. Rudolf Magnus Instituut, Vondellaan 6, 3521 GD Utrecht, The Netherlands.

exist and this may allow additional

of antagonists.

lipid metabolites

structural

to Bay K 8644.

activators

activators

which have of clinical

some of these drugs,

either that they do not act on the channel of calcium.channel

etc)

as for the calcium

of these agents

not reversed by the calcium

endogenous

(class III,

and a wide spectrum

between

on the site of action;

a form which

site and which have

prenylamine,

has a strong

for the sodium channel effects

nicardipine, drugs such as

there will be overlap between

for the two channels

inhibitory

are

as

compared with the myocardlum;

fendiline,

withthe depending

(e.g.

cells);

and diphenylbutylpiperidines

channel

which

(cl~ss II) which bind to sites which are

lidoflazine,

little selectivity

affinities

ischaemic

for blood vessels

diphenylalkylamines flunarizine,

dihydropyridines

linked to the dihydropyridine

less selectivity

uncharged

nitrendipine)

but which act predominantly

in acidic,

in

for other

which are currently

groups:

(class I, e.g. nifedipine,

which may accumulate

role in

and will depend on their site of action

(T, N and L) and on affinity

unrelated

very selective

plays a crucial

effects

effects

on their site of action

of of

of these

in the

channel. Syntex Research Scotland,

Centre,

Research

Park,

Riccarton,

Edinburgh,

EHI4 4AP.

S 13.02 CNS-EFFECTS OF NIMODIPINE W.H. Gispen Evidence is accumulating which suggests that Ca ~- entry blockers of the dihydropyridine type have profound neuro- and psychopharmacological effects in animals and man. The mechanism by which such effects are brought about is still u n k n o w n . It may be that the known vascular effects are responsible for the observed neural activity, whereas an alternative mechanism involves the activation of the dihydropyridine receptors present i~ neural tissue. It is evident that neural Ca 2 homeostasis is a key factor in the control of neuronal plasticity. In the developing nervous system it has been shown that a precize regulation of Ca 2 levels plays a key factor in growth cone motility and thus in network formation. Nimodipine was shown to facilitate maturation of primary cultured rat cerebral neurons in vitro. Furthermore, changes in synaptic plasticity as brought about by long-term potentiation in rat hippocampal syn~pses involve Ca 2 entry and activation of Ca2-sensitive processes. Moreover in the aged nervous system, where in general there is a loss of neuronal plasticity, a severe dysregulation o f neural Ca 2 homeostasis exists. In fact, there are indications that age-, lesion-, or disease-related neuronal cell loss in the brain may in part be attributed to a cytotoxic increase in intracellular Ca 2 . It may be that the antiischemic activity of dihydropyridine relates to the amelioration of cytotoxic effects of high calcium levels. Recent studies have suggested that nimodipine may improve learning and memory processes in brain-damaged or old rats and accelerate acquisition of associative learning in aging rabbits. Post-lesion repair was enhanced by

S 13.03 CALCIUM ANTAGONISTS IN MYOCARDIAL ISCHAEMIA AND REPERFUSION Michael J Curtis*, Michael JA Walker, David J Hearse* (i) Introduction- Ca2+ antagonists have negative inotropic and coronary vasodilatory activity, reduce afterload, inhibit vasospasm, and inhibit isi. It is therefore perhaps surprising that in myocardial ischaemia and reperfusion their clinical utility remains controversial (apart from their established value in angina). Consideration of the determinants and consequences of their tissue-selectivity may help to explain this, and furthermore to facilitate development of more disease-specific drugs. (iil Ischaemia-induced arrh7thmias: In animal experiments, in which high doses may be given, Ca2+ antagonists possess antiarrhythmic activity during regional myocardiaI ischaemia. Minimum effective doses of i.v. (+_)-verapamil are -4).79 mg/kg in anaesthetized dogs 1 and --2 mg/kg in conscious rats2. Antiarrhythmic dose-response curves for a series of Ca2+ antagonists have been examined in the conscious rat with regional ischaemia, atSd antiarrhythmic ED50 values have been compared with ventricular isi-blocking EC5o values. The antiarrhythmic potency order ~ was: (-)-verapamil > nifediplne > (+)-verapamil ;, DHM9:~,4. In isolated rat hems, the -lOgl0 EC50 for inhibition of left ventricular developed pressure (an index ofisi-blocking potency) was different: nifedipine > (-)verapamil > (+)-verapamil > DHM9. However, when the concentration + of K in the perfusion fluid was +increased from 3 meq/1 to 10 meq/1 to mimic changes in extracellular K seen in early ischaemia i~;-blockin~ potency order became identical with anlaarrhythmlc potency o r d e r34" ,. Thus, ischaemia-indiiced increases in extracellular K + appear to confer o n Ca2+ antagonists an isi-blocking site-selectivity for the ischaemic versus non-ischaemic ventricle which correlates with antiarrhythmic activity. Low pH (seen in ischaemia) also potentiates Ca2+ antagonist potency in ventricles5. In man. vasodilatation-induced hypotension makes the use of high doses of Ca2+ antagonists unacceptable. However, animal experiments define an antiarrhythmic mechanism which might be harnessed in man if new Ca2+ antagonists were designed specifically for selectivity for ventricular (versus vascular) tissue, and ischaemic versus non-ischaemic tissue. This site-selectivity can theoretically be achieved by targeting for acidic or partially depolarized myocardium. (iii) Reoerfusiorr-induced arrhvthmias: It is possible that repeffusioninduced arrhythmias play a r o l e in sudden death, particularly in association with Prinzmetal's angina. The calcium-dependence of reperfusion-indnced arrhythmias6 suggests the possibility that reduction of calcium entry during reperfusion might be antiarrhythmic. Reperfusion-

A 21

induced arrhythmias in the isolated perfused heart are indeed inhibited by Ca2+ antagonists but the effect appears to be indirect (mediated by bradycardia leading to slowing of rate of development of ischaemic pathophysiology)v rather than direct (via inhibition of ventricular isi). (iv) Infarct size limitation." Intracellular Ca2+ concentrations are known to rise viith prolonged ischaerrda, and an involvement of Ca2+ in the infarct process has been proposed8. Infarct size limitation has been reported with Ca2+ antagonists. However, sustained benefit usually requires reperfusion, and generally only occurs in species with well-developed collaterals9. In rats (few collaterals) with 24h permanent occlusion, pretreated with phenethylalkylamines (verapamil, anipamil and ronipamil) or 1,4-dihydropyridines (nifedipine, felodipine, DHM9) it has not been possible to demonstrate a dose-dependent reduction in infarct sizeTM. Thus, the ability (if any) of C~/z+ antagonists to achieve a lasting reduction in infarct size probably results from indirect actions such as improvement of collateral blood flow. (v) CardioDleeia: In hearts reperfused after surgery, recovery of function is improved-by cold cardioplegic arrest before and during surgery. Clinically, Ca2+ antagonists have been reported to improve outcome in severely ill patients. However, in animal experiments, although Ca2+ antagonists confer additional protection when added to cardioplegic solutions used at nomaothermia, this protection is lost under hypothermic conditionsl0; this indicates that Ca2+ antagonists and cold cardioplegia may share a common mechanism of action. Conclusion: If therapeutic advantage is to be taken of the myocardial protective effects of Caz+ antagonists, particularly their antiarrhythmic actions, drug development needs to focus upon specific targeting for the ischemic myocardium by making use of such properties as vohage- and pH-dependence. 1. Kaumann AJ, Aramendia P. J Pharm Exp Ther 164:326, 1968 2. Curtis M3 et al. Br J Phammc 83:373, ~1984 3. Curtis MJ, Walker MJA. Br J Pharmac 89:137, 1986 4. Curtis MJ, Walker MJA. Br J Pharmac 94:1275, 1988 5. Briscoe MG, Smith HJ. Card Res 16:173, 1982 6. Tosaki A, Hearse DL Am J Physiol 253:1-/225, 1987 7. Tosaki Aet al. JMol Cell Cardiol 19:441, 1987 8. Riemer KA, Jennings RB. Am J Cardio155:107B, 1985 9. Kingroa JG Jr. et al. Circulation 75(Suppl V):V25, 1987 10. Fukunami M, Hearse DJ. Card Res 19:95, 1984 *Ravne Institute. St. Thomas' Hosuital. London. UK. & Dept. Pharmaeol., University of B.C., Vancouver, Canad~

closely with their ability to block Ca 2+ fluxes through L-type Ca 2+ channels in GH 3 pituitary cells. A linear correlation is observed between inhibition of binding and inhibition of flux for ~-8, 8-~, a-~ and 8-B conformational classes of alkaloids, suggesting that they all bind at the benzothiazepine receptor. This has been confirmed by investigating their effects on the kinetics of diltiazem dissociation. These findings demonstrate that molecules which are structurally distinct from diltiazem will bind competitively at the benzothiazepine receptor. Substituted diphenylbutylpiperidines (DPBP's) such as fluspirilene and pimozide also effect Ca 2+ entry blocker bindinE in cardiac membranes, but equilibrium and kinetic studies indicate that these agents do not interact competitively at any of the known sites in the receptor complex. Direct binding studies with [3H]fluspirilene demonstrate that members of this structural class bind with very high affinity to a distinct site which is coupled by unique allosteric interactions to the other receptors in the complex. Given the uniNue effect of metal ions on fluspirilene binding, (channel substrates inhibit, while channel blockers stimulate ligand binding), the site for substituted DPBP's may be located close to the pore structure of the channel. Even though fluspirilene blocks L-type Ca 2+ channel activity in GH 3 cells, it does not display traditional Ca2+ entry blocker pharmacology in cardiac preparations. These results suggest that it is possible to find modulators of L-type Ca 2+ channels which interact at new sites on the channel, and which possess novel pharmacological properties. Department of Membrane Biochemistry and Biophysics, Merck Institute for Therapeutic Research, P.O. Box 2000, Rahway, New Jersey 07065 U.S.A.

S 14.01

S 14.02

DRUG DISCOVERIES THROUGH RECEPTOR STUDIES G.J. Kaczorowski, V.F. King, J.L. Shevell, J.P. Felix, R.S. Slaughter, and M.L. Garcia Ion channels are multiple drug receptors. In many cases high affinity binding sites for agents that modulate channel activity are coupled by either positive or negative heterotropie interactions. By monitoring well characterized ligand binding reactions, it is possible to discover either structurally unique compounds that interact competitively at known sites, or agents that bind at previously uncharacterized drug receptors on channel proteins. Such an approach has been used to identify novel modulators of the L-type Ca 2+ channel in heart. By studying interactions of [3H]nitrendipine, [3H]D-600 and [3H]diltiazem (representing three different structural classes of organic Ca 2+ entry blockers) in purified cardiac sarcolemmal membrane vesicles, it has been shown that each of these compounds binds to.a unique receptor and that these sites are all coupled allosterieally in a receptor complex which is functionally associated with the L-type Ca 2+ channel. A series of bis-benzylisoquinoline alkaloids (benzylisoquinoline dimers linked in a headto-head, tail-to-tail fashion) have been identified for their ability to modulate Ca 2+ entry blocker binding. Tetrandrine, a component of a Chinese medicinal herb used for treating angina, is a member of this structural class. Tetrandrine possesses a diltiazem-like profile as it modulates ligand binding - it stimulates nitrendipine, but inhibits D-600 and diltiazem binding. Equilibrium and kinetic analyses of the three binding reactions demonstrate that tetrandrine interacts competitively at the benzothiazepine receptor. Interestingly, other members of this structural class which differ in their stereochemistry about the chiral isoquinoline carbon modulate nitrendipineVs interaction in a varied fashion - some stimulate, some have no effect, and some inhibit dihydropyridine binding. Yet these agents block diltiaaem binding with a defined rank order of potency'and this relationship correlates

DO R E C E P T O R B I N D I N G A N D F U N C T I O N S T U D I E S PREDICT CLINICAL RESPONSE? D.G. Grahame-Smith R e c e p t o r b i n d i n g a n d f u n c t i o n s t u d i e s can be u s e d in two ways: a) In d r u g d e v e l o p m e n t as a "screen" to p r e d i c t p h a r m a c o l o g i c a l a c t i v i t y and t h e r e f o r e c l i n i c a l effect. b) D u r i n g d r u g t h e r a p y of i n d i v i d u a l p a t i e n t s to p r e d i c t l i k e l y r e s p o n s e or to m o n i t o r the t h e r a p e u t i c a c t i o n of drugs. In d r u g d e v e l o p m e n t the u s e f u l n e s s d e p e n d s u p o n the e x t e n t of k n o w l e d g e a b o u t the c o r r e l a t i o n s b e t w e e n r e c e p t o r b i n d i n g data, their function, pharmacological effect and therapeutic response. Receptor binding d y n a m i c s c a n a l s o be u s e f u l for p r e d i c t i n g c l i n i c a l e f f e c t s : i.e. s p e e d s of a s s o c i a t i o n and dissociation. Examples where receptor studies have helped to p r e d i c t s o m e a s p e c t s of c l i n i c a l u s e f u l n e s s are: B e n z o d i a z e p i n e s , Dopamine a n t a g o n i s t n e u r o l e p t i c s , p e r i p h e r a l MI anticholinergics. However there are serious d r a w b a c k s in p l a c i n g too m u c h r e l i a n c e in d r u g d e v e l o p m e n t on r e c e p t o r s t u d i e s in the p r e s e n t s t a t e of our k n o w l e d g e . T h e y can but f o r m a small but e s s e n t i a l p a r t ~ of the t o t a l i t y of the s t u d i e s needed. During both drug therapy and drug development the u s e f u l n e s s of r e c e p t o r s t u d i e s d e p e n d s on t h e n a t u r e of the r e c e p t o r b i n d i n g of the drug, the t y p e of p h a r m a c o l o g i c a l r e s p o n s e a n d the links b e t w e e n t h a t a n d the therapeutic response. I. B i n d i n g a n d e f f e c t : " O N - O F F " . R e c e p t o r binding studies with Propranolol predict the acute b l o c k a d e of e x e r c i s e and i s o p r e n a l i n e - i n d u c e d t a c h y c a r d i a ' a n d its t r a n s i e n t nature. O t h e r a c u t e g o o d c o r r e l a t i o n s c o u l d be p r e d i c t e d for

A 22 Cont. S 24.02 anticholinesterases in m y a s t h e n i a g~avis, n a l o x o n e a n t a g o n i s m of m o r p h i n e i n t o x i c a t i o n , a n d f l u m a z e n i l r e v e r s a l of b e n z o d i a z e p i n e coma. 2. D r u ~ R e c e p t o r i n t e r a c t i o n n o t e a s i l y r e v e r s i b l e . T h e b i n d i n g of d i g o x i n , s e v e r a l of the o l d e r M A O i n h i b i t o r s , a n d a s p i r i n (for p l a t e l e t s ) to t h e i r r e c e p t o r s is n o t r a p i d l y r e v e r s i b l e . T h i s leads to r e l a t i v e l y l o n g d u r a t i o n s of a c t i o n a n d s i t u a t i o n s w h e r e p l a s m a d r u g c o n c e n t r a t i o n s do n o t s h o w a g o o d correlation with therapeutic response. Such a c o r r e l a t i o n c a n be r e v e a l e d by r e c e p t o r b i n d i n g a n d f u n c t i o n studies. 3. D r u q - r e c e p t o r c o m p l e x r e v e r s i b l e b u t e f f e c t p r o l o n q e d . E x a m p l e s of t h i s are c o r t i c o s t e r i o d therapy and immunisation. Snap-shot receptor binding and function studies will not predict t h e r a p e u t i c r e s p o n s e in s u c h c a s e s as the c a s c a d e of e v e n t s is too complex. 4. A d a p t i v e R e s p o n s e s A d a p t i v e r e s p o n s e s o c c u r in r e s p o n s e to repeated drug administration. T h e s e m a y lead to i n e f f i c a c y of t h e r a p y , d r u g t o l e r a n c e , or on o c c a s i o n s to t h e t h e r a p e u t i c e f f e c t Adaptive r e s p o n s e s to D i g o x i n , A n t i d e p r e s s a n t s , and Neuroleptics are examples. 5. R e c e p t o r s t u d i e s as a q u i d e to t h e r a p y . R e c e p t o r s t u d i e s c a n a l s o be u s e d as a g u i d e to t r e a t m e n t as in the t r e a t m e n t of c a r c i n o m a of the b r e a s t w i t h a n t i - o e s t r o g e n t h e r a p y . M R C C l i n i c a l P h a r m a c o l o g y Unit, U n i v e r s i t y D e p a r t m e n t of C l i n i c a l P h a r m a c o l o g y , R a d c l i f f e I n f i r m a r y , W o o d s t o c k Road, Oxford, OX2 6HE, UK.

w h i c h is o f t e n a c c o m p a n i e d by an i n c r e a s e in r e c e p t o r number. One e x a m p l e of s u c h a B - a d r e n o c e p t o r r e g u l a t i o n is the e f f e c t of c h r o n i c a d m i n i s t r a t i o n of B - a d r e n o c e p t o r a n t a g o n i s t s . L o n g - t e r m t r e a t m e n t of p a t i e n t s w i t h d i f f e r e n t B - a d r e n o c e p t o r a n t a g o n i s t s leads to an i n c r e a s e in cardiac, v a s c u l a r a n d l y m p h o c y t e B - a d r e n o c e p t o r number, but in a s u b t y p e - s e l e c t i v e fashion: n o n - s e l e c t i v e B - a d r e n o c e p t o r anta g o n i s t s like p r o p r a n o l o l or s o t a l o l i n c r e a s e b o t h c a r d i a c B I - as w e l l as c a r d i a c , v a s c u l a r and lymphocyte S2-adrenoceptors , while B 1 s e l e c t i v e a n t a g o n i s t s like m e t o p r o l o l , a t e n o l o l or b i s o p r o l o l i n c r e a s e o n l y c a r d i a c ~ 1 - a d r e n o c e p t o r s but do not a f f e c t c a r d i a c , v a s c u l a r or lymphocyte S2-adrenoceptors. Again, such c h a n g e s in B - a d r e n o c e p t o r n u m b e r are a c c o m p a n i e d by s i m i l a r c h a n g e s in ~ - a d r e n o c e p t o r responsiveness. Finally, not o n l y d r u g s a c t i n g at B - a d r e n o c e p t o r s but a l s o h o r m o n e s can m o d i f y r e c e p t o r n u m b e r and r e s p o n s i v e n e s s . One t y p i c a l e x a m p l e is the e f f e c t of g l u c o c o r t i c o i d s on Ba d r e n o c e p t o r f u n c t i o n : t h e y can i m p r o v e c o u p l i n g of the r e c e p t o r to the a d e n y l a t e c y c l a s e / c y c l i c AMP s y s t e m thus e n h a n c i n g responsiveness without affecting adrenoceptor number. In a d d i t i o n , t h e y are c a p a b l e of rapidly restoring a decreased receptor density, w h i c h m a y be one of the r e a s o n s for t h e i r c l i n i c a l e f f i c a c y in t r e a t m e n t of asthma.

S 14.03

S 15.01

FACTORS MODIFYING RECEPTOR BINDING AND RESPONSE O.-E. B r o d d e R a d i o l i g a n d b i n d i n g s t u d i e s h a v e g r e a t l y adv a n c e d our k n o w l e d g e on the p h a r m a c o l o g y of - and S - a d r e n o c e p t o r s . W i t h t h i s t e c h n i q u e it was for the first time p o s s i b l e to d e t e r m i n e q u a n t i t a t i v e l y the c o n c e n t r a t i o n of ~ - a n d ~a d r e n o c e p t o r s and, hence, the t i s s u e r e s p o n s i v e n e s s to a d r e n e r g i c s t i m u l a t i o n . It r a p i d l y b e c a m e a p p a r e n t that 5 - a n d S - a d r e n o c e p t o r s r a t h e r than b e i n g s t a t i c e n t i t i e s are d y n a m i c a l l y r e g u l a t e d by a w i d e v a r i e t y of drugs, hormones, pharmacologica ! and physiological c o n d i t i o n s . One i m p o r t a n t e x a m p l e of a c l i n i c a l l y r e l e v a n t c o n s e q u e n c e of r e c e p t o r r e g u l a t i o n is the p h e n o m e n o n of " d e s e n s i t i z a t i o n " , i.e. the fact that f o l l o w i n g l o n g - t i m e e x p o s u r e of ~ - a n d B - a d r e n o c e p t e r s to a g o n i s t s the c e l l u l a r r e s p o n s e is b l u n t e d . In a v a r i e t y of t i s s u e s it has b e e n s h o w n t h a t this a t t e n u a t e d r e s p o n s e is due to a d e c r e a s e in r e c e p t o r number. Such d e s e n s i t i z a t i o n p h e n o m e n a a l s o o c c u r in d i f f e r e n t kinds of d i s e a s e s . For example, in c h r o n i c h e a r t f a i l u r e c a r d i a c ~a d r e n o c e p t o r s are c h r o n i c a l l y e x p o s e d to h i g h c o n c e n t r a t i o n s of e n d o g e n o u s c a t e c h o l a m i n e 8 due to an ( c o m p e n s a t o r y ) i n c r e a s e in the s y m p a t h e t i c a c t i v i t y . AS a c o n s e q u e n c e t h e y m a y be d e s e n s i t i z e d . In fact, s e v e r a l g r o u p s h a v e shown that in p a t i e n t s w i t h c h r o n i c h e a r t f a i l u r e c a r d i a c B - a d r e n o c e p t o r n u m b e r is dec r e a s e d and the m a g n i t u d e of this d e c r e a s e is s t r o n g l y r e l a t e d to the d e g r e e of h e a r t failure. C o n c o m i t a n t l y w i t h the d e c r e a s e in r e c e p t o r n u m b e r c o n t r a c t i l e r e s p o n s e s to 6a d r e n o c e p t o r a g o n i s t s are reduced.

RECEPTOR MEDIATED DRUG INTERNALIZATION

C o n v e r s e l y to d e s e n s i t i z a t i o n , a reduced e x p o s u r e of O~- or B - a d r e n o c e p t o r s to a g o n i s t s leads to the p h e n o m e n o n of " h y p e r s e n s i t i v i t y " ,

Biochem. F o r s c h u n g s l a b o r , Med. K l i n i k and P o l i k l i n i k , U n i v e r s i t y Of Essen, D - 4 3 0 0 Essen, Fed. Rep. G e r m a n y .

Andr~ TROUET : MEDGENIX, Brussels and University Cstholique de Louvain, BELGIUM Receptor specific ligands are increasingly studied as carriers for a more selective drug delivery. The practical design of such receptor mediated delivery systems requires a clear understanding and integration of the various cell biological aspects of receptor localisation, metabolism and turnover. Three modalities of receptor mediated drug internalization will be discussed as well as some applications. 1~ Cytoplasmic receptor mediated drug internalization. Ligands of cytoplasmic receptors such as steroid receptors have already been tested as drug carriers. In this case, the drug itself should be able to cross the cell membrane and two different delivery systems should be considered depending on the nature of the drug to carrier linkage. In the first one, the pharmacological activity of the drug is maintained as a carrier conjugate and the selectivity obtained will not depend on an activation process in the target cell but upon an intracellular concentration gradient, function of the affinity of the ligand for its receptor. In the second case, the drug is inactivated by its linkage and it requires to be activated inside the cytoplasm of the target cell after interaction of the carrier with its receptor. 2 ~ Cell surface receptors mediated drug internalization. The ligand carrier is in this case unable to cross cell membranes and two different areas of intracellular drug action have to be considered : exoplasmic space : this space includes -

A 23

S 15.03 mainly the lysosomes, endosomes and other compartment in indirect contact with the extraeellnlar medium. The drugs do not need to permeate through cell membranes and their intracellular activity does not need to be dependent on a reversal of their linking to the carrier. Possible examples are intralysosomal delivery of anti infectious agents or of enzymes. -Cytoplasmic and nuclear spaces Here the drugs have to permeate through cell membranes and their activity rely on a release of the drug from its llgand. These modes of receptor mediated drug internalization will be illustrated by the targeting and negative targeting of antimalarial and anticancer drugs through linking to lactosaminated albumin interacting specifically with hepatocytic receptors.

S 15.02 J. N. Weinstein Abstract not received by April 30, 1989

TRANSEPITHELIAL AND TRANSENDOTHELiAL PASSAGE OF PROTEIN DRUGS E. Tomlinson Proteins have immense structural variety and variability, hence their consideration and use as therapeutic agents. A host of new peptide and protein drugs are expected to be used. clinically in the coming decades. Polypeptides and proteins proposed for therapy usually have regulatory or homeostatis functions. They include both endogeneous polypeptides and proteins and their (heterologous) derivatives. This latter class of molecules may be produced by, inter alia, site-directed mutagenesis, proteolysis, ligated gene fusion, protein aggregation and/ or conjugation with (other) biologically active effector functions. For a few proteins there is little relation between applied dose and effect, but for most it is highly critical, particularly as non-linear doseeffect relationships are often found, (e.g. with parathyroid hormone, substance P and &-sleep inducing peptide). The administration pattern of a therapeutic polypeptide or protein is often a strong determinant of its resultant pharmacokinetic and pharmaeodynamic behaviour. Endocrine-like or autocfine/paracrine-like peptidergic mediators have very different pharmacodynamic and pharmacokinetic properties than low molecular weight drugs, with each type requiring completely different approaches in their clinical application. This is largely due to their varying ability to move through epi- and/or endothelial barriers, their chemical and/or metabolic instabilities in the central and extravascular compartments, and their chronopharmacological properties. The experimental and clinical literature gives that many putative therapeutic polypeptides and proteins are administered in ways which either do not mimic physiologic delivery patterns, and/or are inappropriate for the biological process(es)which they are intended to modify. Selective drug delivery and targeting seeks to achieve the optimal arrival of drug at its site of action in a manner that is appropriate for the disease and the drug, and which leads to a significant reduction in the possibility for drug side effects. Advances in molecular and cell biology are enabling the production of hybrid fusion protein drugs, and the definition and exploitation of lhe transport routes used by both normal exogeneous materials (e.g. vitamins) and pathogens (e.g. viruses) Transendothelial movement of macromolecular proteins may be through a passive and/or an active mechanism, both of which are often altered by the presence of disease. For example, the size selectivity for the passive extravasation of macromolecules through normal continuous endothelium is for an Einstein-Stokes radius of 8rim, which rises t O perhaps 1000 nm when extravascular inflammation occurs. Transepithelial transport of proteins may also be via a passive and/or an active mechanism. Passive transport occurs to a significant degree in neonates. Evidence for adults is that this occurs to a very small extent. Some proteins and enzymes have been reported to be absorbed through the intestinal tract membrane of numerous species, including chymotrypsin, insulin, horseradish peroxidase, pancreatic lipase, and Serratia protease, etc.; immunoglobulins, intrinsic factor and various hormones are known to be absorbed via a receptormediated endocytosis process allowing specific and rapid uptake of a significant fraction of applied dose. Some groups are attempting to utilise natural transport processes for the effective transepithelial passage of polypeptides and proteins (e.g. the cobalamin/intrinsic factor complex). Although only small, the amounts of protein that can traverse the tract membrane are often described as being significant in terms of pharmacological response. For example, the oral administration of urokinase in adult humans induces a plasma flbrinolytic staging, suggesting the transport of urokinase across the intestinal tract membrane in amounts sufficient to at least stimulate the synthesis and/or release of endogeneous urokinase-type proteins. The process of epithelial transport is often saturable, (as described for numerous proteins including Serratia protease, serum albumin, lipase and [odinated elastase). This present contribution examines how the control of the biological disposition of proteins may be achieved using both protein remodelling and synthetic adduction as well as by various modes of administration. Advanced Drug Delivery Research, Ciba-Geigy Pharmaceuticals, Horsham. West Sussex, RH14 OUT, United Kingdom

A 24

S 16.01 CANCER CHEMOTHERAPY: DOSE INTENSITY AND DOSE RESPONSE W.M. Hryniuk In humans, attempts to define optimum treatment have resulted in many schedules and combinations, and many schemes to reduce doses and delay treatments. However, these schemes and schedules have obscured dose-response relationships. Dose-response relationships can be rediscovered and studied by reducing all to how much drug is given per unit time, as mg/M2/wk. This is dose intensity. Dose intensity may be calculated from intended drug doses ("projected dose intensity") or from dose received after reductions and delays for toxicity ("received dose intensity"). To calculate received dose intensity, treatment delays, and dose reductions and are accorded equal weight arithmetically. For regimens containing only one drug, dose intensity may be calculated simply by disregarding the protocol schedule and expressing the treatment in the standard form: mg/M2/wk. For regimens containing more than one drug, dose intensity can be calculated by arbitrarily choosing one regimen as the standard and expressing all other regimens relative to the standard. Dose intensity Correlates very well with outcome of single and combination agent regimens in various malignant diseases. In animal model systems, dose intensity and total dose (dose intensity x duration of treatment) are independent determinants of antitumor effect. There are insufficient data from human studies to allow the same deduction to be made. Ontario Cancer Foundation, Hamilton Regional Cancer Centre and McMaster University, 711 Concession Street, Hamilton, Ontario, Canada LSV IC3

tumor cells prior to exerting their biological activity. Despite these limitations, there ere areas where TDM could prove of benefit in cancer chemotherapy. Recent studies of oral 6-mercaptopurine (6-MP) in maintenance therapy of ALL of childhood using specific assays have shown that the bioavailability is only 10-20% with large inter- and intraindividual variations. This treatment is usually given for 2-3 years. Yet about I/3 of patients in complete remission relapse. We have repeatedly (median 7 times) determined plasma concentrations of 6-MP in 22 consecutive childran with ALL. 5 patients with low plasma concentrations relapsed. 4 children with much higher concentrations developed severe myelotoxicity necessitating a temporary cessation of the therapy. The results indicate that the plasma concentrations of 6-MP are of significance for the outcome of the treatment although the drug is to be considered a prodrug since 6-MP like nk~ny other antimetabolites is extensively metabolized intracellularly to nucleotide triphosphates which are believed to exert the cytotoxicity. This problem is illustrated by the lack of correlation between the ara-C level in plasma and the ara-CTP-level in leukemic cells isolated from patients receiving high-dose ara-C as single drug therapy. Intracellular ara-CTP but not plasma ara-C correlated to t h e remission rate in relapsed acute leukemia patients. In spite of the growing awareness of the pronounced interindividual variability in the pharmacokinetics of antineoplastic drugs, cancer chemotherapy is most often given in standardized regimens. There are situations where the therapy can be individualized based on drug determinations in plasma or target cells or tissues. Department of Clinical Pharmacology, Karolinska Hospital, RO Box 60500, S-I04 01 Stockholm, Sweden.

S 16.02

S 16.03

CAN D R U G C O N ~ T I O N MONITORING IN ONCOLOGY IMPROVE THERAPY? C. Peterson, J. Liliemark, and P. Lafolie Progress in drug assay methodology during recent years has led to increased knowledge of the pharmacokinetics of antineoplastic drugs. Fof many other drugs, it has bean shown that the plasma concentration provides a better correlation with effect than does the dose. However, the routine use of therapeutic drug monitoring (TDM) in ontology is at present limited to measurement of plasma methotrexate after high-dose therapy where a correlation to toxicity but not to antineoplastic effect has been shown. Plasma concentration monitoring is also used for pharmacokinetically guided dose escalation in phase I trials based on the assumption of a correlation between plasma concentration and toxicity. A typical empirical approach in cancer chemotherapy is to deliver the standard dose of drug or drugs to the patient and then adjust doses on the next cycle, based on clinical observations of toxicity. However, data are accumulating for a dose-response relationship for anticancer drugs not only in predictive test systems in clonogenic cells but also in clinical trials where the dose intensity has been found to correlate to remission rates and patient survival. There are certain factors that make a correlation between plasma concantration and response to anticancer agants mere likely than between dose and response. Pronounced interindividusl variation in the pharmacokinetics has been found for many antineoplastic drugs. Certain drugs show dose-dependent pharmacokinetics. Cancer patients often exhibit changes in drug disposition due to disturbances in liver or renal functions. Other factors make the value of TOM in oncology questionable. Thus certain anticancer drugs exert irreversible binding to DNA and under such circu/r~tances, the time course of effects can hardly be reflected by the ti/ne course of drug concentration in plasma. There are several other problems. Drugs are often used in combination in intermittant courses (eg once every 3-4 weeks), the tumor cell populations are heteroganous, and antimetabolites need to be biotransformed within the

M E C H A N I S M S OF M U L T I D R U G R E S I S T A N C E AND I M P L I C A T I O N S FOR T H E R A P Y T a k a s h i Tsuruo One of the m a j o r p r o b l e m s in c a n c e r c h e m o t h e r a p y is the d e v e l o p m e n t of d r u g r e s i s t a n c e during treatment. The n a t u r e of drug r e s i s t a n c e in cancer patinets is c o m p l e x . One r e a s o n for the c l i n i c a l r e s i s t a n c e is the m e t a b o l i c inactivation, or e x c r e t i o n of a n t i t u m o r a g e n t s by the liver, k i d n e y and other o r g a n s . In addition, it has b e e n f o u n d that t u m o r c e l l s can a c q u i r e r e s i s t a n c e to a n t i c a n c e r drugs. It is g e n e r a l l y a c c e p t e d now that drug r e s i s t a n c e at the c e l l u l a r level ( c e l l u l a r r e s i s t a n c e ) is also an i m p o r t a n t m e c h a n i s m of drug r e s i s t a n c e in patients. T h e r e are two t y p e s of c e l l u l a r r e s i s t a n c e . One is the i n n a t e (natural, de novo) r e s i s t a n c e , and the o t h e r is the a c q u i r e d r e s i s t a n c e to a n t i t u m o r agents. Colon cancer, renal cancer, g a s t r i c cancer and o t h e r solid t u m o r s are known to r e s p o n d only m a r g i n a l l y to a n t i t u m o r agents. This type of c e l l u l a r r e s i s t a n c e is c l a s s i f e d as i n n a t e (natural) drug r e s i s t a n c e . D u r i n g the t r e a t m e n t of t u m o r s w i t h a n t i t u m o r agents, tumor c e l l s can a c q u i r e r e s i s t a n c e to the drugs. This type of r e s i s t a n c e is c l a s s i f i e d as a c q u i r e d drug r e s i s tance. Innate and a c q u i r e d drug r e s i s t a n c e s are major f a c t o r s l i m i t i n g the c l i n i c a l use of ant i t u m o r agents. When tumor c e l l s a c q u i r e r e s i s t a n c e to n a t u r a l l y occurring antitumor agents such as vinca a l k a l o i d s or a n t h r a c y c l i n e s , they g e n e r a l l y show cross r e s i s t a n c e to other a n t i t u m o r a g e n t s h a v i n g d i f f e r e n t s t r u c t u r e s and d i f f e r e n t m o d e s of action. T h i s type of r e s i s t a n c e has been w i d e l y and g e n e r a l l y o b s e r v e d in v a r i o u s e x p e r i m e n t a l t u m o r s , and is c a l l e d " m u l t i d r a g resistance." R e c e n t p r o g r e s s in b i o c h e m i c a l s t u d i e s of m u l t i drug r e s i s t a n c e has r e v e a l e d a g l y c o p r o t e i n as a k e y m o l e c u l e in the m e c h a n i s m s of r e s i s t n a c e .

A 25

S 17.02 This glycoprotein, termed P-glycoprotein, is ass u m e d to be a p u m p i n g molecule of v a r i o u s antitumor agents outside tumor cells. As t h i s protein possesses a key function in m u l t i d r u g r e s i s t a n t tumor cells, t h e r a p e u t i c a p p r o a c h targeting P-glycoprotein would p r o v i d e a lot of int e r e s t and a d v a n t a g e s in t r e a t m e n t of m u l t i d r u g resistance. We f o u n d that P - g l y e o p r o t e i n is a k i n d Of A T P a s e . The inhibitors of the A T P a s e activity of Pglycoprotein can theoretically overcome the resistance. Calcium channel blockers, which were f o u n d in 1981 to be e f f e c t i v e in r e v e r s i n g the drug r e s i s t a n c e , now are p r o v e n to be r e a c t i v e to P - g l y c o p r o t e i a . The a g e n t s , s i m i l a r to calc i u m c h a n n e l b l o c k e r s , w h i c h can i n t e r a c t w i t h Pg l y c o p r o t e i n can a l s o t h e o r e t i c a l l y o v e r c o m e the multidrug resistance. I w i l l d i s c u s s our r e c e n t p r o g r e s s on the d e v e l o p m e n t of n e w a g e n t s e f f e c tive for o v e r c o m i n g of drug r e s i s t a n c e . Finally, monoclonal antibodies raised against Pg l y c o p r o t e i n w o u l d also be e f f e c t i v e for t h e r a p y of drug r e s i s t a n c e as wel.l as for the d i a g n o s i s of d r u g resistance. We h a v e developed two monoclonal antibodies MRKI6 and MRKI7. These monoclonal antibodies can potentiate antitumor effect of the d r u g s a n d a l s o can i n h i b i t the g r o w t h of tumor cells. The a n t i b o d i e s a g a i n s t Pg l y c o p r o t e i n s h o w e d t h e r a p e u t i c e f f e c t in m u l t i drug r e s i s t a n t tumor b e a r i n g mice. In a d d i t i o n to P - g l y c o p r o t e i n , multidrug resistant tumor cells also p o s s e s s other m e c h a n i s m s of r e s i s t a n c e , the m a j o r i t y of them still r e m a i n unclear. T h e o r e t i c a l a p p r o a c h e s by t a r g e t i n g t h e s e m e c h a n i s m s of r e s i s t a n c e may e v e n t u a l l y solve the p r o b l e m s of m u l t i d r u g r e s i s t a n c e w h i c h is c r u c i a l in the t r e a t m e n t of c a n c e r p a t i e n t s . Cancer Chemotherapy Center, Japanese Foundation for C a n c e r R e s e a r c h , Kami-lkebukuro, Toshima-kn, T o k y o ]70, Japan.

S 17.01 M. Califf Abstract not received by April 30, 1989.

ALTERNATIVES TO THE RANDOMIZED TRIAL: THE ROLE OF CASE-CONTROL STUDIES IN PHARMACOEPIDEMIOLOGY M.S. Kramer The case-control design is a potent tool for analytic (cause-and-effect) epidemiologie research that is particularly suited for studying rare or delayed outcomes. In pharmacoepidemiology, case-control studies have been used to study both intended (therapeutic) and unintended (adverse) drug effects. When therapeutic benefits are modest, small clinical trials may lead to inconclusive results. In these cases, case-control studies have been used to improve statistical efficiency. The validity of the casecontrol method can be enhanced by adapting methodologic features of the randomized trial: strict inclusion and exclusion criteria, standardized interview or data abstraction procedures to reduce random and systematic measurement error, and definitions of "exposure" that ensure that the drug under study was taken at an appropriate time and in an appropriate dose to produce the intended effect. But the potential for confounding by the clinical indication for drug treatment is far more difficult to control, unless the reason for treatment or nontreatment is straightforward and can be measured with validity and precision. Thus, for investigating intended drug effects of modest magnitude, a large clinical trial, or a meta-analysis of smaller ones, is usually preferable. Many adverse effects, however, are so rare and/or delayed that even large clinical trials cannot detect them. The casecontrol study is then probably the best available epidemiologic tool. Pharmacoepidemiologic studies should strive, whenever possible, to provide information that can influence the decisions made by clinicians, drug regulators, pharmaceutical manufacturers, and public health policy makers. This information should therefore bear on the relative benefits and risks of a given drug with respect to treatment for the same condition in similar groups of patients. Studies should pose three questions concerning these risks and benefits: (i) To whom do they accrue? (2) For what period of time? and (3) Compared with what? First, drug effects risk should be measured in clinically and sociodemographically relevant subgroups of patients with particular clinical indications. Second, these effects should be evaluated as a function of the time since onset of therapy, since effects (particularly adverse effects) may not be the same after six months of chronic therapy as in the first or second week. Many previous case-control studies of adverse effects have failed on this point, since the only timing issue they addressed was the time of exposure to the drug prior to onset of the adverse event, with no consideration of timing with respect to the onset of treatment. Third, as in clinical trials, it is important to compare the benefits and risks of a drug with those of some other real therapeutic option for patients with the same clinical indication. Most case-control studies of adverse effects have considered drug exposure much as cigar/tte smoking, i.e., presence or absence. In determining the adverse effects of cigarette smoking, it may well be appropriate to compare smokers and nonsmokers. But in therapeutic situations involving patients with clinical conditions that require treatment, the appropriate comparison is usually not drug vs no drug, but among alternative treatments for the same condition. This conceptual framework of evaluating drug effects in the context of risks and benefits and available treatment alternatives leads to several suggestions for future case-control studies in pharmacoepidemiology. Consideration of these issues in future case-control studies may help provide information that is of practical use to clinicians, manufacturers, regulators, and the public health community. Department of Epidemiology and Biostatistics, McGill University, 1020 Pine Avenue West, Montr4al, Quebec, Canada H3A IA2

A 26

S 17.03 NON-RANDOMIZED CLINICAL TRIALS IN CANCERCHEMOTHERAPY

debrisoquina autosomal

Edmund A. Gehan

hydroxylation

controlled with

was

recessive heredity.

Neither sex nor

smoking habits affected.

~uan%itative, comparative c l i n i c a l t r i a l s in cancer chemotherapy can sometimes be accomplished without randomizing patients %o a control group. In experimentation other than c l i n i c a l t r i a l s , the advantages of randomization are unquestioned, but ethical issues in c l i n i c a l %rials suggest the p o s s i b i l i t y of using h i s t o r i c a l control groups in certain circumstances. Factors %o consider in planning a comparative c l i n i c a l t r i a l are: the expected difference between treatments, the knowledge of prognostic factorsj the number of pat i e n t s a v a i l a b l e per year and the s t a t i s t i c a l power and significance level of the t r i a l . Advantages of conduc%ing non-randomlzed control studies w i l l be given and %hose features favoring the nonrandomized t r i a l summarized. Arguments for conducting non-randomized %rials in cancer chemotherapy are: the record of accomplishment in the discovery of new therapies, %he f a c t that a l l knowledge is based on historical e v i dence, smaller sample size and shorter length of study, ethical considerations, recruitment of patients, resolution of controversial questions, s i m p l i c i t y of design and execution, and c r e d i b i l i t y through confirmatory studies. Examples will be given of non-randomized %rials leading %o new knowledge in cancer chemotherapy.

The frequency

distribution

of debrisoquine

meta-

bolic ratio in chinese subjects has been shifted to right.

It probably

of the drug oxidative

showed that metabolism

lower than that in Caucasians. of the reasons

of

the

lower

the capacity in Orientals

is

May be it is one

dosage of drugs used

in chinese clinic. Some pharma~okinetic after a single

oral

parameters dose of 10mg

of debrisoquine of debrisoquine

were evaluated in 11 chinese healthy t 89 of debrisoquine

volunteers:

and 4-OH~debrisoquime

were

2.78~0.44 h and 2.73~0.78 h; K were 0.2552~0.041 7 and 0.2783~0.1047 cant

difference

debrisoquine

h -1.

There was no signifi-

in t89 of debrisoquine

between

but a significant

our and Sloan's

variation

and 4-OHresults,

existed in compari-

son with the data from Silas.

University of Texas M.D. Anderson Cancer Cen%er, Department of Biomathematics, 1515 Holcombe Blvd., Hous%on, Texas 77030, U.S.A.

Preparation

of the human

liver microsomes

(chi~

nese) and its activity have been investigated. Department

of Pharmacology

university,

Beijing,

of Beijing

Medical

P.R. of China

S 18.01

S 18.02

DIFFERENCES IN OXIDATIVE DRUG METABOLISM BETWEEN

DIFFERENCES IN DRUG ACETYLATION BETWEEN ORIENTALS AND CAUCASIANS - - IMPLICATIONS FOR THE INCIDENCE OF ADVERSE DRUG REACTIONSAND ASSOCIATED IDIOPATHIC DISEASES T. Ishizaki and Y. Horai During the last two decades, valuable informations have been accumulated on N-acetylation pharmacogenetics and its clinical implications including the relationships between variations in individual metaboli.c capacity of relevant drugs and their toxic effects and the suscept i b i l i t y of d i f f e r e n t phenotypes to certain idiopathic diseases. Acetylatien polymorphism refers to a genetically determined difference in the N-acetylation capacity of many c l i n i c a l l y useful drugs such as isoniazid (INH), procainamide, hydralazine, dapsone (DDS), and sulfasalazine, as well as some putative carcinogenic arylamines (e.g., be,~zidine). Individuals are classified bimodally as either slow (SA) or rapid acetylater (RA): SAs are autosomal homozygous recessive, while RAs are either heterozygous or homozygous dominants. There are pronounced interethnic differences in the frequency distribution of SAs and RAs between Orientals and Caucasians(Table). I t is interesting Frequency of SAs in Orientals and Caucasians Orientals % Caucasians Ainu 13 British 53-62 Japanese 7-12 Canadians 59-70 Korean ii Czechoslovakians 60 Mainland Chinese 13 Finns 61-64 Ryukyuan 15 French 59 Singapore Chinese 22 German 57 Taiwan Chinese 22 Norwegians 56 Thais 18 Swedes 51-68 Thailand Chinese 34 USA Whites 52-57 to see that the incidence of SAs tends to increase among Orientals residing from the northern to southern geographical regions (Table). This tremendous racial d i f f e r ence between Orientals and Caucasians may be c l i n i c a l l y s i g n i f i c a n t in terms of not only therapeutic response to but also incidence o f adverse e f f e c t s of N-acetylateddrugs i f t h e i r dose is prescribed on the basis of the so-called

ORIENRALS AND CAUCASIANS - ARE THEY IMPORTANT FOR THE CLINICAL USE OF THE DRUGS AFFECTED Y.C. LOU Polymorphic

oxidation of debrisoquine,

codein

and mephenytoin has been investigated and two phenotypes o c c u r

in the chinese

population,

extensive and poor metabolizers. lower

frequency

ne hydroxylation methylatien Caucasian

distribution (I%)

population

a much higher

of poor

S/R enantiometric investigation

in chinese

between t h e

ratio and the mephenytein

drug metabolic

catalyzed by different

of poor

volunteers

ratio which confirms

that

separated genetic

there is

of distribution

(14.7%). We found me correlation metabolic

O-de-

with the data from

(5-9~). However,

frequency

mephenytoin hydroxylation debrisoquine

debrisoqui

and of poor codeine

in comparison

i.e.

There is a

enzymes

control.

previous

reactions

are

which are under

The very similar

results have been found in studies

on debriso-

quine and mephenytoin hydroxylation

phenotypes

in Japanese population.

It showed considerable

interethnic

variations

in Orientals and Cauca-

sians. The results

of chinese

family study

quine hydroxylation

supported

on debrise-

the view

that

A 27

"usual" dose concept. However, clinical significance of acetylator phenotype in relation to therapeutic response to acetylated drugs remains obscure and not uniyersally accepted. For instance, on a theoretical ground, RAs with pulmonary tuberculosis who receive a once-a-week, but not twice-a-week or daily regimen, might become therapeutic failures. Although this has been recommended, i t seems unproven whether acetylator phenotype produces a c l i n i c a l l y significant difference in the outcome of currently used INH regimens. In contrast, there has been an evidence indicating that SAs are more prone to develop INH- and hydralazine-induced peripheral neuropathy, procainamide- and hydralazine-induced lupuslike syndrome, occupational arylamine-induced bladder cancer, and sulfasalazine-induced side-effects. However, whether the above-mentionedadverse reactions would less occur in Orientals than in Caucasians remains unknown. Among idiopathic diseases that have been related to E~cetylation pharmacogenetics,systemic lupus erythematosus and non-occupational bladder cancer seem to be the most controversial ones. Although these two disorders have been reported to occur more frequently in Caucasian SAs, we have not observed any predominance of SAs in the Japanese patients with either of the above-mentioned diseases as compared with the respective controls where RAs predominate very much. Finally, i t is unfortunate to state that clinical implications derived frominterethnic differences in N-acetylation pharmacogenetics between Orientals and Caucasians remain very l i t t l e known. In this context, an interglobal pharmacogenetic study would help settle many aspects of the unresolved interethnic differences in clinical pharmacoepidemiology. Clinical Research Institute, National Medical Center, Toyama 1-21-2, Shinjuku-ku, Tokyo 162, Japan

The m e c h a n i s m s of t h e s e i n t e r e t h n i c d i f f e r e n c e s are n o t yet clear, a l t h o u g h it m a y be s p e c u l a t e d t h a t g e n e t i c o r e n v i r o n m e n t a l f a c t o r s are r e s p o n s i b l e for t h i s p h e n o m e n o n . W h i l e the C h i n e s e w h o p a r t i c i p a t e d in t h i s s t u d y h a d b e e n l i v i n g in S w e d e n for some time (a few w e e k s to less t h a n 8 y e a r s ) , a l m o s t all of t h e m ate C h i n e s e f o o d and k e p t C h i n e s e h a b i t s . It is p o s s i b l e t h a t C h i n e s e f o o d lacks c o n s t i t u e n t s w h i c h i n d u c e g l u c u r o n i d a t i o n , or c o n t a i n s s u b s t a n c e s t h a t i n h i b i t the g l u c u r o n i d a t i o n of c o d e i n e . A d d i t i o n a l l y , the e x i s t e n c e of u n k n o w n m e t a b o l i c p a t h w a y s in the C h i n e s e p o p u l a t i o n can not be e x c l u d e d . H o w e v e r , g e n e t i c and environmental (nutritional, dietetic and even climatic) f a c t o r s s h o u l d be i n v e s t i g a t e d systematically. In s u m m a r y , l a r g e i n t e r e t h n i c d i f f e r e n c e s between Caucasians and Chinese have been shown to e x i s t .in the g l u c u r o n i d a t i o n of c o d e i n e . D i f f e r e n c e s in d r u g m e t a b o l i s m m a y lead to d i f f e r e n c e s in s t e a d y - s t a t e c o n c e n t r a t i o n s , a n d h e n c e in the e f f e c t s of drugs. T h e r e f o r e d o s e s of t h o s e d r u g s w h i c h u n d e r g o e x t e n s i v e c o n j u g a t i o n w i t h g l u c u r o n i c a c i d w h i c h are s u i t a b l e for one e t h n i c p o p u l a t i o n m a y not be a p p r o p r i a t e for a n o t h e r p o p u l a t i o n . IDept of C l i n i c a l P h a r m a c o l o g y , H u d d i n g e U n i v e r s i t y H o s p i t a l , S-141 86 H u d d i n g e , S w e d e n ; 2 D e p t of P h a r m a c o l o g y , C h i n a M e d i c a l ' U n i v e r s i t y , Shenyang, China

S 18.03

S 18.04

I N T E R E T H N I C D I F F E R E N C E S IN G L U C U R O N I D A T I O N OF DRUGS - POSSIBLE MECHANISMS AND CLINICAL IMPLICaTiONS, Q. Yue , J.O. S v e n s s o n 9, J. S~we I T h e o c c u r e n c e of i n t e r i n d i v i d u a l a n d i n t e r e t h n i c d i f f e r e n c e s in d r u g m e t a b o l i s m h a s been well d o c u m e n t e d for d r u g s w h i c h are a c e t y l a t e d or o x i d i z e d in a p o l y m o r p h i c f a s h i o n , but m u c h less is k n o w n in t h i s r e g a r d for d r u g s w h i c h are eliminated by glucuronidation. C o n j u g a t i o n w i t h g l u c u r o n i c a c i d is a m a j o r m e t a b o l i c p a t h w a y for m a n y drugs. It is b i o c h e m i c a l l y c o m p l e x a n d t h e r e b y l i k e l y to be s u b j e c t to b i o l o g i c a l v a r i a t i o n due to b o t h g e n e t i c and e n v i r o n m e n t a l factors. M o r e o v e r , the e x i s t e n c e of m u l t i p l e f o r m s of U D P - g l u c u r o n o s y l t r a n s f e r a s e has b e e n s u g g e s t e d . An i d e a l d r u g for s t u d y i n g g l u c u r o n i d a t i o n s h o u l d be m e t a b o l i z e d m a i n l y by this r o u t e a n d be safe e n o u g h to b e g i v e n to a large n u m b e r of v o l u n t e e r s . C o d e i n e f u l f i l l s t h e s e c r i t e r i a and was u s e d in a s t u d y c o m p a r i n g the m e t a b o l i c p a t t e r n b e t w e e n two e t h n i c g r o u p s , C a u c a s i a n s and C h i n e s e . A s i n g l e oral dose of c o d e i n e (25 mg) w a s g i v e n u n d e r s t a n d a r d i z e d c o n d i t i o n s to 149 u n r e l a t e d h e a l t h y C a u c a s i a n s a n d 133 u n r e l a t e d h e a l t h y C h i n e s e l i v i n g temporarily in Sweden. C o d e i n e a n d its m e t a b o l i t e s in 8 - h o u r u r i n e c o l l e c t i o n s w e r e d e t e r m i n e d by HPLC. The results revealed large interethnic differences, in t h a t the t o t a l u r i n a r y r e c o v e r y of C o d e i n e a n d its m e t a b o l i t e s was 74• in C a u c a s i a n s a n d 60• (meaniSD) in C h i n e s e (p< 0.001). C o d e i n e - 6 - g l u c u r o n i d e a c c o u n t e d for 62% of the d o s e in C a u c a s i a n s , c o m p a r e d to 44% in C h i n e s e (p < 0.001). In c o n t r a s t , u n c h a n g e d c o d e i n e was e x c r e t e d to a m u c h l o w e r e x t e n t in C a u c a s i a n s c o m p a r e d to C h i n e s e (4.3% a n d 7.3% of the dose, respectively; p<0.001).

INTERINDIVIDUAL AND INTERETHNIC DIFFERENCES IN THE METABOLIC ACTIVATION OF THE BIGUANIDE ANTIMALARIALS *+S.A. WARD, *+N.A. Helsby, ** W.M. Watkins, *+G. Edwards, *+ R.E. Howalis & *A.M. Breckenridge. Proguanil (PG) is an arylbiguanide which is used extensively as an antimalarial agent. The drug is relatively inactive per se requiring cytochrome-P450 mediated activation to its principal metabolite cycloguanil (CG). large inter-subject variability in circulating CG concentrations have been observed following oral administration of PG to man (Watkins et. al. 1987 J. Pharm. Pharmacol. 39, 261-265). This variability is due to differences in the ability of individuals to convert PG to 03. k~ have shown that the ratio of PG to CG in either a 0-8 hour urine sample or in a spot urine sample taken from individuals at steady state with respect to PG, is a measure of an individual's ability to form CG (Ward et. al. 1989 Br. J. clin. Pharmacol. in press). We have used this PG/CG ratio to investigate interindividual variability in three separate population studies. Population (i) comprised 135 male British Troops on tour duty in Kenya. All subjects were at steady state with respect to PG and provided a spot urine sample approximately 8 hours after a 200rag dose of PO (po.) The frequency distribution profile of urinary PG/CG was non-normal with ratios ranging from 0.5 to 39. However, 90% of the population formed a discrete distribution with PG/CG ratios between 0.5 and 9.0, with the remaining 10% having ratios between 13 and 39. In a second population study (healthy Europeans, n=80, population study (ii) the frequency distribution profile of PG/CG was similar to the profile obtained from population (i), although only 2 (3%) exhibited a ratio ~ I0. The third population, studied (iii) comprised 75 Kenyan subjects. The frequency distribution profile for PG/CG in this group differed from that obtained from the predominantly European populations (i) and (ii). PG/CG ratios ranged from 0.5 to 69 and although the distribution was again skewed, a discrete distribution between 0.5 to I0 was not apparent, although 90% of the population exhibited ratios between 0.5 and 17. If we compare this distribution with the major mode of the distribution observed in populations (i) and (ii) (PG/CG 0.5-10) 26% of the

A 28 Cont. S 18.04 Kenyan population fall outside this mode. We have shown that this data is not subject to intra-individual variation as subjects (n=30) have had PG/CG ratios determined on two separate occasions at least one month apart without any change i n this ratio. The observation that the frequency distribution profiles for PG/CG differ between European and African populations coupled with the fact that all 26 Gurkha troops studied as part of population (i) exhibited ratios between 0.5 and 3 suggests a genetic basis for the observed variability. We have tested the hypothesis that the metabolism of PG may be controlled either by the debrisoquine or the mephenytoin hydroxylase enzymes and therefore cosegregate with one of the known genetic polymorphisms of oxidative drug metabolism. We have shown that mephenytoin but not sparteine can competitively inhibit the formation of CG by human liver microsomes. We w i l l present data which demonstrate the pharmacokinetic consequences of this variability. We suggest that the metabolism of PG to CG is under the control of the mephenytoin hydroxylase enzyme exhibits a genetic polymorphism in the population, explaining the earlier reports of variability in CG concentrations. The observation that the Kenyan population exhibited generally larger PG/CG ratios than the European populations may indicate a greater incidence of the poor metaboliser phenotype in East Africans and highlights the importance of inter-ethnic differences in drug metabolism. As PG is an extensively used pro-drug the consequences of this polymorphism mey play an important role in both the therapeutic failures seen w~th PG and the development of drug resistance by parasites exposed to subcurative CG concentrations in individuals with the deficiency. *+Dept. of Parasitology, Liverpool School of Tropical Medicine, *Dept. of Pharmacology &Therapeutics, University of Liverpool, U.K., **We]Icome Trust Research Labs. Nairobi, Kenya.

the specific mer~rane receptors for LDL are activated in order to accelerate assimilation of the lipoprotein. Conversely, when the intracellular sterol pool is replete, the receptor mechanism is downregulated in order to protect the cell from the toxic effects of cholesterol acctm~ulation. Defective operation of the receptor, the hallmark of familial hypercholesterolasmia, results in severe and premature coronary atherosclerosis. Here t h e burden of cholesterol elimination falls upon less well understood, receptorindependent mechanisms. These apparently lead to accumulation of cholesteryl esters in the scavenger cells of the monocyte-macrophage system.

S 19.01

S 19.02

PATHOPHYSIOLOGY OF HYPERLIPIDAEMIA

A. Chait Abstract not received by April 30, 1989

The hyperlipoproteinaemias are among the most commonly encountered metabolic derangements seen in clinical practice, and are important because of their frequent association with atherosclerot ic vascular disease. Although their underlying biochemical defects are not yet completely elucidated, sufficient comprehension of normal lipoprotein metabolism has now been acquired to permit us to ascribe mechanisms to these clinical conditions as we know them. Each day we ingest about 120 g of dietary fat containing 500 mg of cholesterol. These lipids are transported in the form of triglyceride-rich chylomicron particles to the bloodstream via the thoracic duct. There they are bydrolysed by the enzyme lipoprotein lipase on the luminal surface of adipose tissues and skeletal muscle capillary beds. More than 95% of chylomicron triglyceride is hydrolysed in this way, leaving behind a relatively cholesterol-rich secondary ("remnant" ) particle. The latter is rapidly cleared from the eirculation by the liver. In the fasting state, the balance of lipoprotein metabolism shifts from the intestine to the liver. The latter is responsible for the synthesis of triglyceriderich very low density lipoproteins (VLDL) which are substantially smaller and denser than chylomicrons. Their initial catabolism also depends on lipoprotein lipase which converts them to cholesterol-enriched low density lipoproteins (LDL) which persist in the plasma for 3-4 days. LDL plays a key role in transporting cholesterol from the liver to peripheral tissues where the lipoprotein is subject to catabolism by at least two mechanisms. The better understood of these depends on the operation of cell membrane receptors and is responsible for the regulated delivery of cholesterol to tissues in response to their structural and metabolic needs. When demands are high,

Cholesterol transport between the liver and peripheral tissues is bidirectional since the sterol cannot be degraded in vivo but must be excreted intact in the bile. The role of reverse cholesterol transport from periphery to liver appears to be performed by another lipoprotein fraction, high density lipoprotein (HDL). In contrast to LDL, HDL seems to protect against atherosclerosis thanks to the activities of apolipoprotein AI, its major protein cormponent. The latter, representing 70% of the total FDL protein, is co-factor for the plasma enzyme lecithin:cholesterol acyltrans ferase (LCAT) which, by esterifying free cholesterol on the surface of the particle, increases its hydrophobicity and promotes its transfer to the lipid-filled core. The vacated sites on the lipoprotein surface are thereby free to accept more cholesterol from the tissues in the enviro~ent. The operation of this sterol acceptor mechaniem is limited by the lipoprotein's capacity for esterified cholesterol. In man this can be expanded many fold due to the existence in his plasma of a protein (cholesteryl ester transfer protein) which is able to shuttle esterified sterol from HDL into VLDL and LDL. Pathological Biochemistry, Royal Infirmary, Glasgow G4

A 29

S 19.03

S 20.01

THERAPEUTIC VALUE OF REDUCTION OF SERUM LIPIDS V. Manninen The medical t r e a t m e n t o f d y s l i p i d e m i a has proved i t s e f f i cacy, and v e r i f i e d b e n e f i t s are now e s t a b l i s e d f o r r e s i n s , f i b r a t e s and n i c o t i n i c acid. Three recent landmark s t u d i e s have overshadowed t h e r e s u l t s o f t h e WHO primary prevent i o n t r i a l and t h e Coronary Drug P r o j e c t (CDP). The p o s i t i v e r e s u l t s o f t h e WHO c l o f i b r a t e (25% f a l l in CHD i n c i dence were n u l l i f i e d by the excess m o r t a l i t y from non-coronary causes in t h e c l o f i b r a t e group. The CDP (secondary p r e v e n t i o n ) , on t h e o t h e r hand, revealed the dangers o f t r e a t m e n t w i t h estrogens and t h y r o i d hormones. Chalestyramine - i s a r e s i n well-known f o r i t s e f f i c a c y in lowering c h o l e s t e r o l . I t was used in the LRC-CPPT (1984), conducted by t h e NIH, USA, on h y p e r c h o l e s t e r a l e m i c pat i e n t s . 3806 men were randomised i n t o t r e a t m e n t and placebo groups. A l l men f o l l o w e d t h e same d i e t a r y regime. In t h e cholestyramine group, t h e f a l l in LDL-C was 20.3% and i n t o t a l - C 13.4%. A f t e r seven years f o l l o w - u p CHD m o r t a l i t y was down by 24% and n o n - f a t a l cardiac events had f a l l e n by 19% i n t h e t r e a t m e n t group. The H e l s i n k i Heart Study (HHS)(1987) compared g e m f i b r o z i l w i t h a placebo i n 4081 middle-aged men w i t h primary hypsrc h o l e s t e r o l e m i a but otherwise h e a l t h y . A mean f a l l i n LDLC o f 10%, T6 -35% whereas and a r i s e i n HDL-C o f 11% were seen a f t e r 5 years f o l l o w - u p i n t h e t r e a t m e n t group, which experienced an o v e r a l l 34% (p
CLINICAL P H A R M A C O L O G Y OF ACYCLOVIR: LESSONS FOR A N T I V I R A L DRUG D E V E L O P M E N T P. S. L i e t m a n The d e v e l o p m e n t of acyclovir as an antiherpes drug serves as a m o d e l of antiviral drug development and provides several lessons w o r t h considering as the general area grows. I. It is possible to create a drug that has remarkable "selective toxicity" towards the virus as contrasted to the host. 2. The selective toxicity of acyclovir is critically dependent on the intracellular activation of acyclovir to acyclovir m o n o p h o s p h a t e by a viral enzyme. 3. The intracellular p h a r m a c o k i n e t i c s of acyclovir as a p r o d r u g as well as the active m e t a b o l i t e s of acyclovir are important. 4. The conventional e x t r a c e l l u l a r p h a r m a c o k i n e t i c s of acyclovir are also important, e s p e c i a l l y with respect to oral absorption, renal elimination, and overall pharmacokinetics. 5. Rational dosing of acyclovir may include d o s i n g at more frequent intervals in order to reduce the cost of the drug. 6. Rigorous clinical trial m e t h o d o l o g y has allowed the e f f i c i e n t regulatory approval of the drug as well as a c c e p t a n c e by clinicians. It w o u l d seem reasonable to apply these lessons to the a c c e l e r a t e d search for new drugs for AIDS and other viral diseases. Division of Clinical Pharmacology, The Johns Hopkins U n i v e r s i t y School of Medicine, 600 N. Wolfe St., Baltimore, M a r y l a n d 21205, USA.

S 20.02 PROGRESS IN ANTIVIP~L TREATMENT OF RESPIRATORY INFECTIONS G.G. Jackson Much developmental knowledge and clinical experience ~ith potential and p r a c t i c a l aspects o f a n t i v i r a l therapy have c o m e from the treatment os v i r a l respiratory infections. Three f a c t o r s are i m p o r t a n t , ( 1 ) r a p i d d i a g n o s i s o f the s p e c i F i c viral etiology, (2) antivira] activity of the drugs and ( 3 ) t i m e l y pharmacologic d e l i v e r y o f a c t i v e compounds t o the s i t e os i n f e c t e d c e l l s . Interferon was f i r s t recognized in t h e p r e v e n t i o n o f experimental influenza. It's broad spectrum and host r a t h e r than v i r a l specificity gave hope o f a v o i d i n g etiologic diagnosis. But i n t e r f e r o n and i n t e r f e r o n inducers e l i c i t e d pharmacologic, l o g i s t i c and b i o l o g i c problems in t h e r a p y . Amantadlne Has among the f i r s t safe, e f f e c t i v e a n t i v ] r a l drugs f o r systemic use. I t and t h e analogue r i m a n t a d i n e remain major means f o r dru9 p r e v e n t i o n and t r e a t m e n t o f I n f l u e n z a A. Absorbed from the i n t e s t i n a l tract, the action is specific for Influenza A and mediated by i n h i b i t i o n of virus uncoatin9. The pharmacokinetics and t o x i c i t y are compound, t i s s u e and age r e l a t e d . The s y n t h e t i c nucleoside~ r i b a v i r i n , inhibits viral s y n t h e s i s and has been c l i n i c a l l y effective in t h e t r e a t m e n t o f both I n f l u e n z a A and B. Administration by small p a r t i c l e aerosol is useful in RSV and i n f l u e n z a ] pneumonia. R h i n o v i r u s common colds can be a l t e r e d using several classes o f compounds. Most promising are molecules t h a t e n t e r " t h e canyon" o f r h i n o v i r u s s t r u c t u r e and p r e v e n t necessary conformational changes in t h e v i r u s . Therapy of viral respiratory infections illustrates ne~ly recognized and d i v e r s e a n t i v i r a ] mechamisms and a range of pharmacologTc requfrements in T h e i r a p p l i c a t i o n . Medical M i c r o b f o l o g y ( V i r o l o g y ) The London Hospital Medical Colles Turner ST. London El 2AD England

A 30

S 20.03

,. Coo,ey

Abstract not received by April 30, 1989

S 21.01 IN V1VO HUMAN PET NEURORECEPTOR IMAGING D.F. Wone. L.T. Young. G. Pearlson. L. Tun~, D. Yogng, H. Sit]get. R.F. Dannals. C. Ross. A.A. Wilson. H.T. Ravert. ,l. Links. H.N. Wagner, Jr., A. Gjedde The development of radioligand receptor binding techniques over the last two decades has had a major impact on the study of neuropsychiatric disorders. Such techniques have resulted in a large number of pharmacological tools to investigate neurotransmitter receptor mechanisms. Positron emission tomography (PET) has allowed the development of techniques to image neuroreceptors in vivo in human brain through modifications of these radioligand techn-iques. Neuroreceptors which have been examined with PET include: D 1 and D2 d o p a m i n e r g i c , 5HT-2 s e r o t o n i n e r g i c , opioid, adrenergic, nicotinic and muscarinic receptor systems. , Novel neurotransmitter and receptor systems such as s i g m a and glutamate (NMDA) systems among others, are beixig Currently investigated in several PET centers. We present here some of our work e x a m i n i n g D 2 dopamine receptors in ''~ several neuropsychiatric disorders to i l l u s t r a t e this important p h a r m a c o l o g i c a l technique. We have continued to study D2 dopamine receptor density (Bmax) in manic depressive illness (MDI), Tourette's Syndrome (TS), and schizophrenia (SCZ) with improved PET methods u s i n g [C-11] 3 - N - m e t h y l s p i p e r o n e (NMSP). A multiple regression model of B m a x vs linear and quadratic terms of age was fitted to combined normal and patient data. Comparing MDI and normals, mean Bma x in psychotic MDI (28.7+12.4 pmol/g, N=8; mean age 44.1+15.9) was significantly higher than in both nonpsychotic MDI patients (18.9+_10.0, N=7; mean age 48.8+20.2) and normals (15.1• N=19; mean age 37.3+_21.0). The regression could not distinguish between nonpsychotic MDI and normals (p<0.01). However, SCZ and psychotic MDI revealed elevated B m a x compared with normals. Although mean SCZ (34.2• pmol/g, N=19; mean age 41.9-+21.8) and psychotic MDI data were not significantly different, the shape of the data curve for SCZ supported both linear and quadratic terms of B m a x falling with age. The psychotic MDI had a different intercept frown nonna.ls but B m a x did not fall with age. There was a significant positive c o r r e l a t i o n between Bmax and the degree of psychosis (Present State Exam). All 5 TS patients had elevated Bm a x values (27, 33, 36, >100 and 31 pmoles/g). Elevated D2 dopamine receptor densities occur in several neuropsychiatric disorders and may be related to complex factors t h a t - m a y include the presence of psychosis. It has been suggested that methodological issues may have contributed to reported B m a x differences in SCZ (Science 234: 1558, 1986) which include: [ C - H ] labelled metabolite corrections, plasma protein binding, serum haloperidol (HAL) measures, and brain HAL partition coefficients. Experiments were performed to address such issues: (1) Plasma l l c - N M S P metabolites measured by HPLC were compared with input function corrections in our model. Multiple regression using a fitted curve (activity vs a power function of time) showed no s i g n i f i c a n t differences between HPLC and modelled corrections (N=10 subjects). (2) There were. no differences in plasma protein binding of l l C _ N M S P in 21 patients (95.7• and 11 controls (95.6• (3) Serum HAL measures with a more sensitive (20 fold) assay correlated closely (r-0.8) with previous HAL concentrations. Bm a x estimates i n previously studied patients were still elevated when computed with these more sensitive HAL measurements. (4) HAL partition coefficients in guinea pig brain correlated closely with assumptions used in our PET studies. Our improved PET techniques continue to demonstrate elevated mean D2 B m a x in drug naive SCZ patients as demonstrated in our earlier work. In addition to these c l i n i c a l findings, v a l i d a t i o n s of assumptions and improvements in our PET methods, other models to examine neuroreceptors with PET will be presented. These include approaches using reversible ligands such as 11C-Sch23340 which binds to D1 dopamine receptors and l l c NMSP which binds to cortical 5HT-2 receptors. Our findings demonstrate the complexity of these techniques and suggest potential future applications of PET. Nuclear Medicine Tower Basement, Johns Hopkins Hospital, Baltimore, MD 21205

S 21.02 APPLICATION OF NMR TO DRUG METABOLISM IN THE BRAIN A.L. Benabid, C. Remy,M'. Decorps. S. Lotito. A. Francois. J.F. Le Bas, H. Reutenaner. Nuclear Magnetic Resonance Spectroscopy (NIvIRS) has the unique advantage of probing, atraumatically and repeatedly, the chemical composition of living organisms. A variety of nuclei as well as technical improvements provide the neuropharmacologist with a powerful tool. NMRS in vivo is able to study in vivo the effects of drugs on metabolism and also to foIIow the fate of these drugs in the organism when they are labetled by nuclear markers such as 19F or 13C. Recently, image guided spectroscopy has provided an additional possibility to localize the effects and/or the fate of the drugs in the various parts of the brain. In vivo situations actually include ceils in culture, isolated perfused organs and organs in situ. NMRS of ceils in culture is not easy to perform. Although this reduetionist approach has its intrinsic limitations, it provides a convenient modeI for the precise investigation of pharmacological effects on cell metabolism. In situ NMRS studies of the brain provide the closest conditions to physiology and allow investigations of models of nervous diseases as well as the effects of drags on the brain.The non invasive nature of NMRS makes it possible to repeat the measures without destroying the sample or even interfering with its metabolism. Some atoms have a noclea~ magnetic momentum called spin and are widely used in Biology due to tlieir metabolic importance or to their presence in drags. Each of these nuclei have a very characteristic resonance frequency in a given magnetic field. The chemical shift of this resonance frequencyhas been extensively used by the chemists to decipher the structure of molecules and is used in biological spectroscopy to recognize and observe variouschemicai species in a given sample. 31P brings informations about cellular energetic metabolism and intracellular pH. IH is very sensitive and provides important complementary metabolic data, such as lactate. 13 C gives access to the Krebs cycle and enables the tracing of metabolic pathways using 13 C-labelled molecules but is very expensive. 19 F is 'almost absent from the organism but is present in many drugs ~ d therefore used as a tracer for in vivo kinetic studies. NMRS is one of the few.techniques which "allowthe non invasive biochemical study of living tissues in their almost normal situation inside the organism, through several procedures. Chronic implantation of surface coils on the skull is particularly adapted to the study of the brain in non anesthetized animals. Another way leads to the recent and fast developing field of the spatially localized and eventually image guided spoctroscopy which make possible precise biochemical measurements in perfectly localized areas of animal and human brains. Specific appmacbes such as superfused slices and cell cultures are obviously adapted to neurophar-macologv at the cellular and/or molecular NMRS allowed the in vivo simultaneous follow-up of several metabolites. The survey of biochemical effects on organs such as the brain by potassium cyanide provides a perfect example of this use of NMRS. The metabolic changes follow a typical pattern of cellular anoxia. The time courses of pHi and lactate are decoupled under the effect of anesthetics, suggesting a partial antidotal effect which depends on the nature of the anesthetics used. Enzymatic fluxes determinations by saturation transfer are difficult experiments to perform but they open a window on the study of the drag modulated enzyme regulation in vivo. NMRS is also useful to study the effect of drugs or of therapeutic procedures on the metabolic patterns of pathological conditions such as brain ischemia. Hyperglycemia worsens the situation, as does bifemerane. Naloxone improves acidosis while metEnkephalin has no effect. Calcium antagonists prevent or correct these ischemia induced changes. Moreover, it is now possible to study the intracellular Calcium concentration by 19F NMRS. NMR spectra of the human brain have been obtained in newbom infants and in adults. The availability of 1.5 and up to 4 Tesla imaging systems allows to perform 1H brain images and to select areas from which 31P and 1H spectra are obtained using spatial localization techniques. This procedure is well suited to the follow-up of brain tumor radiation therapy or chemotherapy. The most interesting contribution of NMRS to pharmacology is to detect in vivo and on time the metabolites which are produced by the cellular processing of drugs. When the drug is labelled, with 13C or more often with 19F, the detection covers all the generated products, regardless of whether they were expected or not. Fluphenazine has been observed in vivo in the rat brain by 19F-NMRS, 7Li-NMRS has permitted to observe Lithium in the rat and human brains. Recent technical improvements should open to NMRS the highly interesting field of in vivo psychopharmaeology. The fates of Halothane and of 5FU have been investigated by 19F-NMRS During the last decade in vivo NMRS has proven to be a very powerful and performing tool in physiology and pharmacology. The limitationsare still severe in some situations and call for more technical improvements. The even more recent human applications, almost routinely performed on adequate equipments, tell us without ambiguity that these neuropharmacological studies will soon be possible in patients, for whom therapy will be more conveniently monitored and adapted. LMCEC, INS ERM U. 318, Department of Biophysics, Medical School, Joseph Fourier University of Grenoble, 38700, La Troncbe, FRANCE.

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S 21.03 REGIONAL 3-DIMENSIONAL CORRELATION OF POSITRON EMISSION TOMOGRAPIIIC AND MAGNETIC RESONANCE STUDIES OF BRAIN METABOLISM AND PHARMACOLOGY. A C Evans Quantitative interpretation of functional images (PET or SPECT) is limited by poor spatial resolution and low counting statistics. For many tracers, contrast between different brain structures is low and anatomical differentiation is difficult. Finally, normal tracer distributions can be severely distorted by such gross pathologies as stroke, tumor and dementia. Hence, the complementary anatomical information provided by CT or MRI is essential for accurate and reproducible analysis of functional images. The incorporation of anatomical information into the regional quantification of functional data can be considered as two separate problems: registration of anatomical/functional images and anatomical segmentation of the functional image. Numerous methods have been proposed for the registration of PET and MRI data. In the past these have been designed so that the same anatomical plane is scanned in both systems. Such approaches involve careful re-positioning and have encountered difficulties with uncooperative or demented subjects. Latterly, three-dimensional (3D) imaging hardware has allowed the development of volumetric acquisition and processing of data. Image registration can now be performed by postprocessing and arbitrary planes through registered image volumes generated as required. Image volume registration can be performed interactively, by matching of external head contours as observed from each modality or by direct superposition of equivalent points (fiducial or anatomical) identified within each volume. Problems of differential slice thicknesses still contribute to inconsistent partial volume effects and sampling artifacts. This is particularly of concern for small structures adjacent to CSF such as the caudate nucleus, a structure which plays a central role in PET studies of motor and psychiatric disorders. Once matched MRI/PET datasets are obtained, the specific zones from which functional measurements will be taken have to be identified, preferably according to a standardized classification of neuroanatomical regions. Methods for matching computerized regiomof-interest (ROI) atlases to the anatomical data have been explored by a number of eentres. Approaches range from computer-controlled deformation of a normal atlas to fit the image, using some objective matching criteria, to more interactive procedures which sacrifice some objectivity to allow detailed local modification and inclusion of lesion structures. At the MNI, work has been continuing on the 3D correlative imaging and analysis of MRI, PET, CT and digital subtraction angiography (DSA). Using a 1.5 Tesla MRI scanner and a 15-plane high-resolution PET scanner, we register MRI and PET volumes with a point-to-point mapping algorithm which minimizes the mean square distance between paired points. Examples of combined anatomical/functional images will be shown for various diseases, including stroke, tumor and degenerative conditions, and for various systems, including glucose metabolism, blood flow and dopamine neurotransmission. To segment the PET data, we have previously developed a computerized brain atlas which is modified interactively to fit each subject's brain, based on the MRI image. Comparison of this approach with direct interpretation of the PET images demonstrated a mean reduction in inter-observer variability by a factor of 2-3 for both localization and functional measurement across a set of 25 brain structures. This 2D approach required careful planning to obtain matched planes from MRI, PET and the brain atlas. We have now developed the means to display and modify a 3D version of this methodology, such that MRI, PET and VOI structures can be matched in three dimensions. McConnell Brain Imaging Unit, Montrgal Neurological Institute, Montreal, Qudbee.

S 22.01 TREATMENT OF MYOCARDIAL INFARCTION WITH RT-PA M . L . L . Simoons. MD, FESC~ F A C C Thrombolytic therapy has now been established to restore bloodflow to t h e ischemic myocardium in the majority of patients, which limits infarct size, and preserves cardiac function. In comparison with placebo, thrombolytic therapy improves early and longterm survival after myocardial infarction. The most widely tested thrombolytic drugs are streptokinase (SK) and rtPA, and both have been shown to be effective. In comparative studies rt-PA appeared more effective than SK to achieve coronary reperfusion (62 vs 31% of patients) and coronary patency (70 vs 55% of patients). The most widely used dose of rt-PA is iO0 mg administered over 3 hrs (i0 mg bolus, 50 mg/hr, 40 mg/2 hrs). Other regimens presently under evaluation may yield higher patency rates. Reocclusion can occur after thrombolytic therapy, and has been reported in 718%. Concomittant treatment with heparin and aspirin is recommanded to prevent reocclusion. Bleeding complications are common at the sites of vascular access. However, intracrananial hemorrage is infrequent (0.5-1.0% of patients). I n large placebo controlled trials stroke was not more prominent after SK or rt-PA than after placebo. Infarct mortality has been reduced dramatically due to the introduction of thrombolytic therapy. The lowest mortality rates have been reported in studies with rt-PA, ranging from 3% to 7% at 2 to 4 weeks ! A series of studies have demonstrated that systematic immediate or' early angiography and additional revascularisation are not mandatory in patients treated with rt-PA. Such additional invasive therapy is only indicated in 5 to 20% patients who develop recurrent myocardial ischemia.

S 22.02 RECOMBINANT PRO-UROKINASE: MOLECULAR PROPERTIES AND THERAPEUTIC PROFILE L. Floh~ Saruplase, i.e. the non-glykosylated full-length urokinase-type plasminogen activator, is obtained from genetically transformed Escherichia coli (L. Floh~, Eur. Heart J. 6, 905, 1985). In some respects saruplase behaves like an inactive zymogen, but it physiologically activates plasminogen in the presence of fibrin (H.J. Lijnen et al., J. Biol. Chem. 261, 1253, 1986). Correspondingly effective fibrinolysis without induction of a lyric state can he achieved in animal models of thrombosis or embolism. As evident from a multi-center double-blind streptokinase-controlled study in 401 patients (communicated by J. Meyer on behalf of the PRIMI study group at 61st Scientific Sessions of the American Heart Association, Washington, D.C., November 14-17, 1988) saruplase is clinically effective in the treatment of evolving myocardial infarction: Application of 80 mg saruplase induces rapid recanalization of infarct-related arteries, results in high patency rates (72 % at 60 min after onset of treatment) and is associated with a low incidence of reocclusions (i or 5 % depending on definition of subgroup), bleeding complications requiring transfusions(4 %) and in-hospital mortality (3.5 %). It is concluded that saruplase compares favourably with the fibrinolyric drugs available so far. Grfinenthal GmbH, Forschungszentrum, Zieglerstra~e 6, D-5100 Aachen

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S 22.03 Abstract not received by April 30, 1989

be f i t t e d ~o t h e n a t u r a l course of the disease. To r e d u c e i n s u l i n r e s i s t a n c e the t h e r a p e u t i c s t e p s r e q u i r e d s t a r t w i t h n o r m a l i z a t i o n of body w e i g h t , reduced i n t a k e of saturate~d f a t and p h y s i c a l e x e r c i s e , i f a p p l i c a b l e . Only thereafter pharmacologic intervention by betacytotropic s u l f o n y l u r e a may be i n i t i a t e d , p r e f e r a b l y in t h e n o n - o b e s e , h y p o i n s u l i n e m i c patient. In c o n t r a s t , b i g u a n i d e s , which may improve g l u c o s e uptake by muscule t i s s u e , are r e s e r v e d f o r obese NIDDMs, w h i l e a l p h a glucosidase inhibitors are r e s t r i c t e d to improve postprandial glycemia after polysaccharide ingestion. Insulin treatment, however, should o n l y oe i n i t i a t e d once b l o o d glucose values consistently remain above the t a r g e t range d e s p i t e the p a t i e n t ' s strict adherence t o a p p r o p r i a t e t r e a t m e n t . I.Medizinische Universit~tsklinik, L a z a r e t t g a s s e 14, A-I090 Wien A u s t r i a .

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RATIONAL TREATMENT O'F NON-INSULi~ D~ENDENT (TYPE 2) DIABETES: DOES IT EXIST? W.Waldh~usl A v a i l a b l e forms of t r e a t m e n t of n o n - i n s u l i n d e p e n d e n t d i a b e t e s (NIDDM) r e l y on n o r m a l i z a t l o n of oouy w e i g h t in t h e obese, on administration of u r a l a n t i d i a b e t i c agents including sulfonylureas, b i g u a n i d e s and possibly inhibitors of i n t e s t i n a l p o l y s a c c h a r i d e a b s o r p t i o n as w e l l as on i n s u l i n i f any o t h e r form of t r e a t m e n t f a i l s to r e a s o n a b l y improve c a r b o h y d r a t e m e t a b o l i s m . Such approach p e r m i t s good m e t a b o l i c c o n t r o l o n l y in about 25% of a l l NIDDMs. To improve such u n s a t i s f a c t o r y therapeutic outcome one has to u n d e r s t a n d the h e t e r o g e n o u s causes of i n s u l i n i n d e p e n d e n t h y p e r g l y c e m i a , commonly r e f e r r e d to as NIDDM. I t is c h a r a c t e r i z e d by f a s t i n g h y p e r g l y c e m i a due to i m p a i r e d g l u c o s e c l e a r a n c e and i n c r e a s e d h e p a t i c g l u c o s e p r o d u c t i o n , which i s attributed to e x c e s s i v e p r o v i s i o n of g l u c o n e o g e n i c p r e c u r s o r s from p e r i p h e r a l t i s s u e s , p r e d o m i n a n t l y muscle. A s s o c i a t e d i n s u l i n r e s i s t a n c e may be p o t e n t i a t e d by dietary habits causing a disproportionate rise in plasma s a t u r a t e d f a t t y a c i d c o n c e n t r a t i o n . In a d d i t i o n , NIDDM d i s p l a y s a l o s s of t h e c e p h a l i c phase of i n s u l i n r e l e a s e as w e l l as n y p e r - and h y p o i n s u l i n e m i c h y p e r g l y c e m i a . In c r o s s - s e c t i o n a l s t u d i e s , more marked n y p o i n s u l i n e m i a was seen w i t ~ more s e v e r e h y p e r g l y c e m i a . Such i m p a i r e d i n s u l i n s e c r e t i o n is o n l y o b s e r v e d in r e s p o n s e to g l u c o s e , but not to a r g i n i n e and may be due t o a genuine d e f e c t of t h e B - c e l l g l u c o r e c e p t o r . A g a i n s t t h i s background r a t i o n a l t r e a t m e n t of NIDDM has to be a d i f f i c u l t task~ which has to

Antiarrhythmic agents. T. Meinertz, MD Allg. Krankenhaus St. Georg, Lohmuehlenstr.l ,2000Hamburg I Long-term antiarrhythmic therapy is mandatory in patients with lethal or malignant ventricular arrhythmias, i.e. ventricular arrhythmia~ that produce a hemodynamic consequence (severe presyncope, syncope or cardiac arrest). Most often the underlying arrhythmia is sustained ventricular tachycardia or ventricular fibriletion. These patients should always be evaluated and treated in the hospital by continuous electrocardiographic monitoring and by invasive electrophysiologic t~sting. Potentially lethal ventricular arrhythmias, i.e. frequent ventricular premature complexes, ventricular pairs aud nonsustained ventricular tachycardia, although not producing hemodynamic consequences, occur in the presence of structural cardiac disease. Patients with this combination of factors have a moderately increased risk of sudden cardiac death. AIthough it is hoped that antiarrhythmic drug therapy will prevent sudden cardiac death by reducing ventricular premature complexes and nonsustained ventricular taehycardia also in this group of patients, the final proof of this hypothesis is still lacking and currently undergoing evaluation in several controlled clinical trials. Whereas patients in this category with less overt degrees of ventricular dysfunction can safely be treated as outpatients, patients with severe ventricular dysfunction should be evaluated and managed in the hospital. In patients with potentially lethal ventricular arrhythmias long-term antiarrhythmic therapy isguided by Holter monitoring. Patients with benign ventricular arrhythmias have the most favorable prognosis: Minimal to no risk of sudden cardiac death. Patients with this type of arrhythmia are characterized as having no important structural cardiac disease and no arrhythmia related hemodynamic consequences. Elimination of symptoms should he the therapeutic goal if present to a degree that interferes with the patients lifestyle. In general these patients can be appropriately managed in the out.-patient setting usin~ noninvasive Hol-

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S 24.01 t e r monitoring. Whenever possible long-term antiarrhythmic therapy should be avoided. Ideally the etiology of a ventricular arrhythmia and its provoking stimulus should be identified, and the arrhythmia treated specificially. In most cases, however, the etiology and the provoking stimuli of an arrhythmia cannot be identified, and treatment becomes empiric. The characteristics of a ventricular arrhythmia are recognized as inaccurate predictors for a particular patient's response to antiarrhythmic therapy: "Every attempt at treatment is an uncontrolled experiment". There are, however, certain clinical indications that I drug may be preferable to others, if only because of reduced likelihood of adverse effects. The effectiveness of the conventional or first -generation antiarrhythmic agents is unpredictable and many patients faile to respond to treatment. The adverse effects of these drugs alsolimit their use especially during longterm treatment. Data from recently published controlled clinical trials suggest that newer antiarrhythmic agents such as mexiletin or class l-C-agents (flecainid, propafenon, encainid)or sotalo] are more predictably effective with a lower incidence of adverse effects. Treatment with a combination ofan~arrhythmic agents should be considered if several single agents were proven to be ineffective or if additional protection is required for patients with a life-threatening arrhythmia. A combination of agents allows lower dosages to be used, thus minimizing adverse systemic and noncardiac affects, while allowing additive electrophysiologic effects. Long-term tolerance is also improved by a reduction in dose-related adverse effects. Up to now very few data are available concerning the use of combination treatment during long-term therapy.

S 23.03 LONG TERM MEASUREMENT OF ANTI-RHEUMATIC DRUG EFFECTS IN RHEUMATOID ARTHRITIS J, R. Kirw~n Rheumatoid arthritis (RA) affects 2% of the population. Half of these seek medical attention and may suffer severely. The onset and pattern of RA are very variable. For many patients the disease is slowly or rapidly progressive. Bouts of inflammatory activity add to an increasing burden of structural joint damage. In the past, efforts to assess drug effects have avoided the difficulties such variation and progression add to therapeutic assessment by concentrating on measuring the biochemical and clinical evidence of disease processes. This has distracted investigators from the need to assess disease outcome and has resulted in relatively short term evaluations of efficacy. In practice, RA is a long-term disease and therapeutic trials should take this into account. Long term trials must address the need to maintain treatment over long periods and the ethics of placebo control. They must measure many aspects of the patients' quality of life-disability, discomfort, social and economic costs - and must be sufficiently powerful to detect clinically meaningful benefits. Studies of sufficient size and length are possible and are currently being conducted. Their design and rationale will be reviewed. Rheumatologists are facing the problem of long-term outcome assessment and have been developing and using new assessment procedures. Rheumatology Unit, University Department of Medicine, Bristol Royal Infirmary, Bristol BS2 8HW, U.K.

PHANMACODYNAMIC MODELLING N.H.G. Holford Si~ole models of drug action are w~ll established in theory and are widely used to describe in vitro pharmacological phenomena. These models, based on the Law of Mass Action, provide a quantitative basis for the interaction of drugs with binding sites and the subsequent transduction to an observable pharr~cological response. They have come to be used to describe in vivo actions of drugs although the assumptions on which they rest are not usually verifiable. More sophisticated models describing the time course of drug action in vitro were developed many years ago at the time the "biophase" concept was introduced. The application of models incorporating time dependence has been most prominent in descriptions of drug effects in vivo with some striking insights into the relationship between structure, function and pharmacology. Models of drug interaction can easily become conlolex. However, the application of simple models for simple competitive antagonism can help understand the extent and time course of commonly used medicines e.g. beta adrenocept or antagonists and angiotensin converting enzyme inhibitors. Some drug actions are best described as quantal, the action is either present or absent e.g. anti-arrhyt~nic effects. Although a quantal model may be needed to describe the observable drug action an underlying continuous action may best ezqolain the mechanism e.g. altered cardiac conduction or repolarization. An important application of pharmacodynanic models is the prediction of drug effects in vivo which are not directly observable. For exa~01e, the cumulative drug effect may be predicted from the integral with respect to time of a readily observed phenc~nenon. The desired therapeutic effect may be more closely related to some integral of the effect rather than the instantaneous effect itself. This concept has been applied to understanding the effects of glucocorticoids. Holford NHG. Drug effect prediction ~n u~uo. in Systems & Control ~ncyclopedia. pp. 1244-1249 Edited by MG Singh. Perg~non Press, Oxford. 1988. Department of Pharmacology and Clinical Pharmacology, University of Auckland School of Medicine, Private Bag, Auckland, New Zealand

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POPULATION PHARMACOKINETICS

NEW APPROACHES TO EVALUATING THE ABSORPTION PROPERTIES OF THE GASTRO-INTESTINAL T R A C T D. Brockmeier Drug therapy is predominated by oral formulations, since the oral route is the most convenient and popular way o f applying a drug. However, the fate of the drug molecules in the gastro-intestinal tract and during absorption can significantly influence the safety and efficacy of drug therapy. Particularly with extended release formulations or drugs with slow dissolution rates (low solubility) it is important to know whether the drug is absorbed throughout the gastro-intestinal tract with the same rate constant or whether the rate constant differs markedly from site to site. The following large-scale invasive techniques have been used to study the site-dependent absorption of drugs and nutrients: I. intubation with multi-luminal catheters (with and without occlusion) and endoscopy, II. HF-capsules with an extracorporal trigger for drug release, IIl. scintigraphic techniques in combination with the deconvolution method. The intubation technique and the HF-capsules have demonstrated for a small number of drugs that the rate and amount of absorption may be different for the various segments of the gastro-intestinal tract. Both higher and lower rate constants of absorption have been observed for the lower part as compared to the upper part of the gastrointestinal tract; with some drugs, e.g. furosemide, the rate of absorption falls almost to zero in the lower part. Markedly smaller rates of absorption in the lower part explain the variable bioavailability observed. The smaller the rate constant of absorption in the lower part, the greater the variability in bioavailability. Recently a new, less invasive approach has been elaborated to study the absorption properties of the gastro-intestinal tract. It compares the in vitro results of drug dissolution with the hypothetical in vivo profile of dissolution in a detailed point by point manner (continuous in vitro/in vivo correlation). It is essenti~il for this approach that the in vitro dissolution profiles of the extended release formulation are isomorphic or at least homomorphic under reasonable variation of the dissolution conditions and/or apparatus. In this context, homomorphism basically means that the dissolution profiles obtained under different test conditions can be superimposed by linear transformation of the time axis. In the Clinical part of the new approach, such formulations have to be studied in a crossover design with an oral solution in order to estimate the hypothetical in vivo dissolution profile by deconvolution. With some drugs, i.v. application may he used instead of an oral solution. The homomorphism of in vitro dissolution profiles can be determined by comparing those times required by the various dissolution test methods until the same fractions are dissolved; times but not amounts have to be compared in this method. With homomorphic profiles, the correlation of times related to identical fractions dissolved will result in a straight line. The in vitro and the hypothetical in vivo dissolution are compared in the same way (continuous in vitro/in vivo correlation). This correlation will result in a straight line provided I. the true in vivo dissolution profile is homomorphie with the various in vitro dissolution p r o files and II. the absorption properties do not change while the f o r mulation is moving down the gastro-intestinal tract. The former prerequisite is most likely to be met if the formulation shows homomorphic in vitro dissolution profiles. Homomorphism of in vitro and in vivo dissolution profiles has been confirmed for some formulations by scintigraphy. Deviations from the straight line relationship therefore indicate changing absorption conditions along the gastro-intestinal tract. The method has been applied to data from different drugs for which the extended release formulation studied has shown homomorphie properties in the in vitro test. The data were collected from internal company studies as well as from the literature. The evaluation e m ployed only the data of drugs for which the absorption from different segments of the gastro-intestinal tract has also been studied using one of the above mentioned techniques. The comparison with these results shows that the new method is as sensitive as the more invasive techniques. It is concluded that a carefully designed pharmaceutical formulation can be used as a test probe to screen the absorption properties of the gastro-intestinal tract for the drug considered. The new approach o f fers a wide field of applications, e.g. since the clinical part requires only blood sampling, the method can be used in patients and even the influence of a gastro-intestinal disease on absorption may be considered. Hoeehst AG, Klinische Forschung, Postfaeh 800320, D-6230 Frankfurt/M-80, FRG

S. Vozeh and K. Fattinger Population pharmacekinetics are being applied by an increasing number of investigators. This is primarly due to the fact that since several years a generally available software (NONMEM) exists to perform this complex data analysis. The important advantages of the population pharmacokinetics, compared to "individual" approaches, are the use of large patient samples from a representative population and the estimation of the variability of the pharmacokinetic parameters. Both characteristics are essential if the results are to be used for designing optimum dosing regimens. For reliable a priori dosing regimens that should result in a large proportion of patients within a desired concentration range, it is important that the data have been obtained in patients actually treated with the drug and that interindividual pharmacokinetic variability had been taken into account. A population average value within the "therapeutic" range by no means precludes the possibility that a large proportion of patients will have either toxic or subtherapeutic concentrations. Quantitative estimates of the interindividual variability based on a representative patient sample are also needed for an efficient individual dose adjustment if therapeutic drug monitoring is used with Bayesian feedback. Population pharmacokinetics represent also a powerful tool for an exploratory analysis to investigate factors that may influence the pharmacokinetics of a drug. These advantages have, however, their costs: assumptions about the pharmacokinetic and statistical model, complex data analysis requiring high level of expertise and experience, and the possibility of bias inherent to every exploratory data analysis. Both violation of the model assumptions and the presence of bias can often remain undetected during the analysis. For this reason, it is very difficult, if not impossible, for the data analyst (or a reviewer) to be sure that the analysis has been performed "correctly" and that no important bias is present. It has been therefore suggested that the results of a population data analysis be validated on a data set that was not included in the analysis. Ideally this should be done on a separate patient sample. The different possible approaches for validation of the results will be discussed with the help of concrete examples. Although the presentation will concentrate on only one method used in population pharmacokinetic analysis (the first order method implemented in NONMEM) it should be pointed out that other approaches have been proposed (e.g. the non parametric maximum likelihood method) that may significantly influence the further development in this field. To our knowledge, NONMEM is presently the only method for which software is available. Division of Clinical Pharmacology, University of Basel and Intercantonal Office for the Control of Medicaments, Erlachstrasse 8, CH-3012 Bern / Switzerland

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S 25.01 IMMUNOPATHOGENIC MECHANISMS OF HIV INFECTION P. Biberfeld. Recent c l i n i c a l as well as experimental findings seem to indicate a broader eel1 tropism of HIV than f i r s t recognized. Thus antigen presenting c e l l s of the dendrit i c c e l l system~ monocytes-macrophages, bone marrow stam celZs, gut-mucosal c e l l s of the nervous system in addition to T-helper c e l l s may become targets and mediate pathogenic e f f e c t s in various tissues during HIV i n f e c t i o n . The rate of i n f e c t i o n seems to depend on HIV-CD4 i n t e r a c t i o n but alternate/complimentary mechanisms off i n f e c t i o n may be of importance in vivo. Apart from d i r e c t e f f e c t s of HIV, other pathogenic mechanisms based on humoral and c e l l mediated reactions to HIV a n t i gens in vivo may be implicated in HIV associated disease. In addition the immunodeficieney of HIV i n f e c t i o n s allows the manifestation of pathogenic agents and mechanisms leading to opportunistic i n f e c t i o n s and tumors. Thus the therapeutic requirements for treatment o f HIV i n f e c t i o n s are by necessity disparate and complex. Immunepathology Lab., Department of Pathology, Karolinska I n s t i t u t e & Hospital, S-I04 Oi STOCKHOLM, Sweden.

cases may double or triple. The urgency of the HIV/AIDS epidemic prompted the establishment of the WHO Global Programme on AIDS (GPA), with the objectives of preventing HIV transmission, reducing the morbidity and mortality associated with HIV infection, and unifying national and international efforts against AIDS. Biomedical Research Unit, Global Prograrmme on AIDS, World Health Organization, Avenue Appia, 1211 Geneva 27, Switzerland

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WORLDWIDE EPIDEMIOLOGY OF HIV-INFECTION J. Esparza, J. Chin and J. Mann As of April, 1989, more than 140,000 cases of AIDS have been officially reported to the World Health Organization (WHO) from 145 countries. However, WHO estimates that about 450,000 cases may have already occurred globally. Large numbers of cases have been reported from North America, Latin America, Oceania, western Europe and areas of central, eastern and southern Africa. Available serological evidence indicate that, at the present time, there are between five million and ten million people infected with the human immunodeficiency virus (HIV), worldwide. From the analysis of the seroprevalence data and the number of reported cases, three broad epidemiological patterns of HIV/AIDS can be distinguished. In areas with Pattern I (North America, western Europe, Oceania, and parts of Latin America), HIV began to spread extensively in the late 1970's and most cases occur among homosexual or bisexual males and urban intravenous drug users, with an overall prevalence of less than I% but of over 50% in some groups of persons practising high-risk behaviours. In Pattern II areas (some Sub-Saharan African countries and, increasingly, in some parts of Latin America and the Caribbean), the virus also began to spread in the 1970's; most cases occur among heterosexuals with an overall seroprevalence of more than I% and up to 30% of males and females in the sexually active groups of some large urban areas. The male to female ratio is approximately 1:1, and as a result, mother-to-infant transmission is common. In Pattern III areas (eastern Europe, North Africa, Middle East, Asia and most of the Pacific), HIV was introduced in the early to mid-1980's, with only small numbers of cases reported, the majority in persons who had travelled to Pattern I or Ilareas, who had received contaminated imported blood products, and increasingly among intravenous drug users. Over one million cumulative cases of AIDS are projected by the end of 1991 and by the mid-1990's, the toll of AIDS

C L I N I C A L P H A R M A C O L O G Y : A N E S S E N T I A L S T E P IN ANTI-HIV DRUG DEVELOPMENT D.M. K o r n h a u s e r The e p i d e m i c of H I V i n f e c t i o n has s t i m u l a t e d a w o r l d - w i d e s e a r c h for e f f e c t i v e d r u g t h e r a p y . In v i t r o s y s t e m s c a p a b l e of t e s t i n g large n u m b e r s of c o m p o u n d s for a n t i - H I ~ a c t i v i t y have been developed; many compounds with anti-HIV activity have been identified. However, the development of therapeuticagents from active compounds has been difficult. A n i m a l m o d e l s of H I V d i s e a s e in w h i c h c o m p o u n d s c a n be t e s t e d for in v i v a t h e r a p e u t i c e f f i c a c y are l i m i t e d . Consequently, compounds with anti-HIVactivity ,have b e e n a d m i n i s t e r e d to m a n e a r l y in the drug development process and these p h a r m a c o l o g i c s t u d i e s h a v e s e r v e d to i d e n t i f y the t o x i c i t i e s and a c t i v i t y of the c o m p o u n d s in viva. The d e s i g n of t r i a l s has b e e n c o m p l i c a t e d by the v a r i o u s s t a g e s o f H I V i n f e c t i o n , the u n p r e d i c t a b l e p r o g r e s s i o n of the d i s e a s e in i n d i v i d u a l s u b j e c t s , t h e s e r i o u s n a t u r e of the illness, a n d the d i f f i c u l t y in i d e n t i f y i n g s u i t a b l e e n d p o i n t s for e v a l u a t i n g e f f i c a c y a s i d e f r o m d e a t h or the d e v e l o p m e n t o f opportunistic infections. Fundamental principles ofclinical pharmacology r a n d o m i z a t i o n of s u b j e c t s , b l i n d i n g of o b s e r v e r s a n d i n c l u s i o n of p l a c e b o c o n t r o l s h a v e b e e n i m p o r t a n t f a c t o r s in the d e s i g n of successful studies. When these principles have been neglected, study results have been a m b i g u o u s or u n i n t e r p r e t a b l e . S t u d i e s in H I V - i n f e c t e d s u b j e c t s e m p l o y i n g m a n y d i f f e r e n t d r u g s h a v e d e m o n s t r a t e d t h a t i__nn v i t r o a s s a y s of a n t i - H I V a c t i v i t y a n d e x p e r i m e n t s in a n i m a l m o d e l s c a n n o t

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Cont. S 25.03 s u b s t i t u t e for w e l l c o n d u c t e d c l i n i c a l studies. F a i l u r e to d e m o n s t r a t e in v i v o e f f i c a c y (HPA 23), u n a c c e p t a b l e t o x i c i t y (suramin) a n d a p r e v i o u s l y u n r e c o g n i z e d toxicity (dideoxycytidine) of the c o m p o u n d , and s p e c i e s s p e c i f i c m e t a b o l i s m (zidovudine) h a v e a l l b e e n i d e n t i f i e d in t r i a l s of a n t i - H I V a g e n t s in i n f e c t e d s u b j e c t s . These examples u n d e r s c o r e the r e q u i r e m e n t for t h o r o u g h i n v e s t i g a t i o n s of a n t i - H I V c o m p o u n d s in infected subjects. Careful clinical p h a r m a c o l o g y p e r f o r m e d e a r l y in d e v e l o p m e n t and a p p l i e d to t r i a l s of a c t i v i t y a n d t h e r a p e u t i c e f f i c a c y w i l l s p e e d the a v a i l a b i l i t y of n e w t h e r a p e u t i c a g e n t s w h i l e the lack of r i g o r in h u m a n s t u d i e s w i l l l e a d to u n c e r t a i n t y a b o u t the b e n f i t s of s p e c i f i c a g e n t s a n d d e l a y the a p p e a r a n c e of n e w d r u g s . Division of Clinical Pharmacology, Johns H o p k i n s U n i v e r s i t y S c h o o l of M e d i c i n e , O s l e r 525, 600 N. W o l f e St., B a l t i m o r e , MD U S A 21205.

In our progress towards the development of an effective chemotherapy for AIDS, we observed the following: I. Among the anionic substances, ATA has a specific affinity for the CD4 receptor, thus preventing the attachment of EIV to the CD4 cells. That ATA selectively interacts with CD4 could be ascertained by using specific monoclonal antibody to cell surface markers: only the binding of 0KT4A (leu3A) was prevented by ATA. II. Various ddN analogues exhibit a selectivity against HIV that is comparable to that of azidothymidine (AZT), and some of these ddNs (i.e. D4T, FddCiUrd) are markedly less toxic than AZT for bone marrow cells. Unlike AZT which piles up in the cells as AZT 5'-monophosphate because the latter blocks thymidylate kinase that is needed for its further conversion to the 5'-di- and 5'-triphosphate, D4T and FddCiUrd do not show an accumulation of their 5'-monophosphate forms. III. PMEA has greater anti-retrovirus activity than AZT in murine retrovirus models in rive, end its therapeutic potential as an anti-AIDS drug is now being explored in cats and monkeys (against feline AIDS and simian AIDS, respectively). IV. Unlike AZT and other ddN analogues, sulfated polysaccharides (and sulfated polymers in general) are able to block syncytium formation between HIV-infected and uninfected cells. We have recently demonstrated that this syncytium formation is accompanied by a selective destruction of the uninfected (target) cells by the HIVinfected (agressor) cells. In this respect, one chroniwipe out hundreds if net cally HlV-infected cell ma thousands of uninfected CD4 cells. This phenomenon may play an important role in the pathogenesis of AIDS, in that it may explain the dramatic depletion of 0D4 + T-iymphocytes in AIDS patients. Thus, effective means that block this phenomenon, such as the sulfated polymers, may be therapeutically advantageous over those compounds (i.e. AZT) that do not affect syncytium formation. Rega Institute for Medical Research, K.U.Leuven, i0 Minderbroedersstraat, B-3000 Leuven, Belgium.

S 25.04

S 26.01

FUNDAMENTAL ASPECTS OF ANTI-AIDS CHEMOTHERAPY Erik De Clereq In our approaches to the chemotherapy of AIDS, we have established the following classes of compounds as potent and selective inhibitors of HIV replication : Class I. Anionic substances such as suramin, Evans Blue, aurintricarbo~ylic acid (ATA), fuchsin acid, glycyrrhizinic acid and bile acid derivatives. Class II. DideoxTnucleoside (ddN) analogues such as 2',3'-didehydro-2',3'-dideoxycytidine (D4C). 2',3'-didehydro-2',B'-dideoxythymidine (D4T), 3'-azido-2',3'-dideoxy-2,6-diaminopurineriboside (AzddDAPR) and 3'-fluoro2',B'-dideoxy-S-chlorouridine (FddCIUrd). Class III. AcTclic nucleotide analogues such as the phosphonylmethoxyethylpurine derivatives 9-(2-phosphonylmethoxyethyl)adenine (PMEA) and 9-(2-phosphonylmethoxyethyl)-2,6-diaminopurine (PMEDAP). Glass IV. Sulfated polysaccharides such as dextran sulfate, pentosan polysulfate, %-carrageenan, mannan sulfate, heparin and various non-anticoagulant derivatives thereof, and synthetic polymer sulfates such as polyvinylalcehol sulfate and copolymers thereof with acrylic acid. Whereas class I compounds may be inhibitory to both virus adsorption and reverse transcription (or yet other processes), class II and class III compounds are assumed to he specifically targeted at the reverse transcriptase. To this end, class II and class III compounds must be phosphorylated intracellulerly to their 5'-triphosphate or diphosphorylphosphonate derivatives, respectively. Sulfated polyacoharides and sulfated polymers in general (class IV) would owe their anti-HIV activity mainly to inhibition of virus adsorption to the cells. Those compounds that block virus binding to the cells, and thus interfere with the interaction between the viral envelope glycoprotein gpl20 and the cellular CD4 receptor, may also be expected to block giant cell (syncytium) formation between HIV-infected cells (expressing gpl20 at their surface) and uninfected cells (bearing the CD4 receptor).

CHANGING STRATEGIES IN WHOLE ANIMAL LONG-TERM CARCINOGENICITY TESTING R. Kroes Several decades have emerged since Dr. Arnold Lehman led actions to provide better information on drug safety. Carcinegenicity testing has been one of the requirements in most, if not all, national regulations. A number of drugs, primarily used as anticancer agents, hut also used as therapeutic agents (incl.hormonal) otherwise, have been found to be human carcinogens, whereas others are considered to be suggestive for such an effect. These findings have had great influence on todays caroinogenicity testing for chemicals and for drugs in particular. Todays testing should include a careful consideration of the carcinogenic mechanisms involved, in order to provide the necessary and indispensable basis for evaluation and regulatory decisions with scientific merit. Short term tests, especially those aiming at detecting genotoxieity are of great help in the prephase of carcinogenicity testing, but certainly cannot be considered conclusive by themselves. Their results may give however, guidance for the sequence and design of in vivo carcinogenicity testing. Carcinogenicity testing, its past, current status and development will be discussed. National Institute of Public Health and Environmental Protection, Antonie van Leeuwenhoeklaan 9, P.O.Box ], 3720 BA Bilthoven, The Netherlands.

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S 26.02

S 26.03

PREDICTIVE VALUE OF SHORT-TERM TESTS : AN OVERVIEW. M.Roberfroid

APPROACHES OF A HEALTH AUTHORITY TO RISK ASSESSMENT OF NEW AND OLD DRUGS R. Bass The results of risk assessment by health authorities are often seen only as risk-benefit decision on the marketing authorization/status of a drug, i.e. under well defined conditions and on a ease by case basis. Such decisions should ensure that patients are provided with efficacious drugs and are prevented from using unsafe ones. This scientific balancing of risk and benefit has approx, the same legal background world-wide: health authorities are expected to presume that a drug is of poor quality, unefficacious and unsafe - unless proven otherwise. For new drugs the data base to be made available to prove absence of unacceptable potential risks for man stems mainly from pre-clinical routine animal studies. As soon as unacceptable risk potentials occur, they need to be verified/falsified. Whereas the necessary routine studies can be derived from guidelines, the type and extent of testing for trouble-shooting is often unpredictable. For major risk areas to be assessed by toxicological studies (tumorigenicity, mutagenicity, embryotoxicity, other irreversible toxic effects) the human counterpart will not be available for risk assessment, at least not for new drugs. Correlation between animal and man then depends on (quantitative) comparison, e.g. through pharmacokinetics. Risk assessment will yield a decision, independent on the availability of the amount and usefulness of data at a pre-set point in time and independent on the data which may be obtained in the future. Since reasoned courage barely exists, the possible error from planning, performing, evaluation and risk assessment is always placed on the safe side thus overruling case by case scientific expectation. Institut ftir Arzneimittel des Bundesgesundheitsamtes, Seestr. 10, D - 1000 Berlin 65

To evaluate the t o x i c i t y o f a drug is a very complex and r i s k y task. I t is the o b j e c t i v e of modern t o x i c o l o g y to challenge that p r e d i c t i o n by e x t r a p o l a t i n g r i s k f o r humans from data obtained using in V i t r o or in Vivo animal models. Carcinogenicity is one of the major r i s k which need to be e v a l u a t ~ w i t h great caution. One o f the o b l i g a t i o n o f t o x i c o l o g y today is to become more s c i e n t i fic. Indeed most of the protocols and most practices f o r t o x i c i t y t e s t i n g (including l i f e - l o n g c a r c i n o g e n i c i t y ) have no or only a very weak s c i e n t i f i c basis. They have been used f o r long and repeated practices have validated t h e i r use. To become more s c i e n t i f i c , t o x i c o l o g y has to develop and to use tests based on precise knowledge of the mechanisms of the e f f e c t s which cause that p a r t i c u l a r toxicity. During the l a s t 15 years, short-term t e s t s , usually based upon mutagenicity or some other response to DNA damage, have been developped with the view to detect possible carcinogens. Yet besides a l l the progress that has been made the s i t u a t i o n concerning the deployment o f the tests to predict the carcinogenic potential o f drugs in a r e g u l a t o r y context is s t i l l confused. In p a r t i c u l a r theim use in p r e d i c t i n g wether or not a substance has the a b i l i t y to cause cancer in humans is questionned mostly because that p r e d i c t i o n appears not to be as accurate as i t was expected in e a r l y days. Indeed from 90% at that time, the accuracy f i g u r e s have declined and the most recent study indicated that in the Ames Salmonella assay t h e ' p r e d i c t i v i t y of a mutagenic response f o r carcinogenic i t y was 75% and of a non-mutagenic response f o r non-car c i n o g e n i c i t y 48%. With an expert l i k e B.A. Bridges, one may argue that most o f the problems started to a r i s e whenthese studies became routine tests conducted under defined protocols rather than as experiments designed to t e s t s p e c i f i c hypotheses. The s c i e n t i f i c dimension these tests had brought to t o x i c o l o g y appeared to be l o s t due to the development o f a check l i s t approach. This trend must be reversed i f the proper place o f shortterm tests is to be r e a l i s e d . I t is now abundantly cl ear t h a t an evaluation o f p o t e n t i a l c a r c i n o g e n i c i t y f o r an agent requires an integrated assessement o f a l l a v a i l a b l e informations. In a r e g u l a t o r y context, the choice o f short-term t e s t must be founded on basic s c i e n t i f c p r i n c i ples and may not necessarily be the same f o r each agent. Some f a c t o r s w i l l be considered that must be taken into consideration i f short-term tests have to become part o f a more s c i e n t i f i c toxicology. Universit~ Catholique de Louvain, Department o f Pharmaceut i c a l Sciences, Unit o f Toxicological and Cancerological Biochemistry, UCL 73 69, Avenue Mounier 73, B1200 Brussels Belgium.

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Oral Presentations

OP 01.01

OP 01.02

C L I N I C A L E V A L U A T I O N OF C A R D I A C O U T P U T M E A S U R E M E N T BY T H O R A C I C E L E C T R I C A L BIOIMPEDANCE G. Castor. J. Motsch. P. Altmaver, J. Helms, G. Molter, I. N i e d e r m a r k Thoracic electrical bioimpedance (TEB) is a noninvasive method for continuous determination of left ventricular stroke volume and cardiac output (CO). It is generally accepted as a precise trend monitoring, but the accuracy of the measured absolute values is still a matter of debate. Therefore, the accuracy and reproducibility of TEB CO-measurement by a computerized system ( N C C O M 3 - R 7 Cardiovascular monitor, Bomed, Ltd, Irvine, CA) was compared with standard thermodilution (TD) C O - m e a s u r e m e n t (Cardiac output computer 9520A C O - E d w a r d s , Santa Ana, CA) under various conditions. In total the determined data of 1966 CO-measurements were compared and statistically analysed using Pearman-correlation Test. The overall correlation was r = 0,9474 (n = 1966) with a slope of 0,89 and'an intercept of 0,33 l/rain. PEEP during low f r e quency ventilation resulted in high intrathoracic pressure with a c o n c o m i t a n t higher intrathoracic air volume and a reduced blood volume, which did not influence determir~_tion of CO (r = 0,912, n = 155 vs r = 0,926, n = 155 during Z E E P ventilation). Measurement of CO in apnoe did not correlate (r = 0,77,n = 265) as good as measurement during the first third of inspiration cycle under mechanical positive pressure ventilation (r = 0,836, n = 260). Only a poor correlation was found (r = 0,56, n = 142) in hyperdynamic septic state patients ventilated with PEEP, whereas a correlation of r = 0,70 (n = 257) was calculated in septic patients ventilated with ZEEP. This might be due to an overestimation in hyperdynamic state by TD. The results demonstrate that TEB is a reliable noninvasive method for measuring absolute levels of b e a t - t o beat stroke volumes and CO in humans. It might become a valuable tool for investigation of pharmacodynamic effects of cardiac active drugs and for evaluation of cardiovascular-side effects of new pharmaceutics. Department of Anaesthasiology, University of Saarland, D-6650 Homburg-Saar, F R G

A MICROCOMPUTERIZED SYSTEM FOR EVALUATING THE COGNITIVE ACTIONS OF DRUGS IN THE YOUNG, ELDERLY AND DEMENTED. K.A. Wesnes, P.M. Simpson & L.C. Christmas Traditional techniques for assessing the eognitive effects of drugs have not been able to meet the demands placed upon them by recent drug development. This Is strikingly evident in the development of cognitive enhaneers to treat age-associated cognitive impairment. In Phase I work, there has been not only an absence of human models to evaluate these compounds, but also few tests sensitive enough to detect improvements in cognitive performance. In patient studies, tests designed to identify the presence of dementia have frequently been used to detect changes in cognitive efficiency produced by these compounds. However, as these tests were not designed for repeated use, their sensitivity for this purpose is extremely limited. The Cognitive Drug Research Computerized Assessment System has been developed to remedy these various shortcomings. The tests incorporated in the System have all previously proven sensitive to drug improvements as well as impairments. In young people this System is used with a scopolamine model of dementia to assess the ability of novel compounds to antagonize this cholinergically-based impairment in cognition. Parallel versions of these tests have been specifically developed for use in trials to assess the ability of compounds to improve cognition in Age-Associated Memory Impaired patients, and either to arrest or reduce the decline in cognition of demented patients. This paper will describe (a) the use of this System in a scopolamine model and its sensitivity to cognitive enhancers, (b) a parallel version of the System for use with elderly non-demented patients and its drug sensitivity, and (c) the validity and test-retest reliability of a version for demented patients and its ongoing use in English and European Multi-Centre trials. Cognitive Drug Research, 13 The Grove, Reading RGI4RB UK

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OP 01.03

OP 01.05

T ~ 30 MI~DTE UREAm3C BROTH TESt IS NONINVASIVE, RAPID A ~ E C G N ~ CAL FOR TH~APEUTIC MC~rfrOPdNG OF ~ c r ~ P?L~Y (CP) INFECTIC~S R.H. Eqqers, F.E. L6dtke, R. Teqeler, G. Lepsien, and F.E. Bauer. Cp, an urease ~esitive hecteri~, is related to gastrednodenal lesions and to high relapae rates of duodenal ulcers in man. In a preliminary study Graham et al. (Lancet 1987 I, 1174) propesed a 3 hours breath test using 350 mg tSC-ures. In the present study this test was further developed. Methods: Fifty four patients with different endescopically dco~mented gastrednodenal lesions received 200 ml 0.i N citric acid and 75 ,g tsC-urea p.o. Ten of the participants were tested several times with different doses (350, 150, 75 rag). Three Cp positive patients with a four weeks treatment with colloidal bismuth subsalicylate (CBS) 1.8 g/day combined with amoxycillin 2.25 g/day starting at day 15 were monitored 3 times/week by the urea breath test. Breath samples were collected before and after applicatien of urea at I0 rain intervals for 60 rain and measured by stable isotope ratio mass spectrometry. Resttlts: IsC02 exhalation was expressed as _%dose per mmol _CC= produced per kg _body weight (%D/CBW). Citric acid used as test meal had no effect en *sC0z/t20~ ratios. The results were independent of the dose of teen, 75 m~ being optimal. Forty Patients (74%) were Cp positive as measured by culture, microscopy, end teeese test. Within 30 rain these Cp pemitive patients developed tsCfh exhalation rates of 0.44-5.63 %D/CBW in contrast to Cp negative Patients with <0.044 %D/CBW (p<0.00001). The sensitivity of the IsC0z urea breath test was 98%, specificity 93%. Mcmitoring of CBS monotherapy revealed a fall of %D/CBW of approx. 60~ within day 1-3 with no further reduction. Ccabinati~ of CBS pies amc0~cillin further reduced %D/CBW to values obtained in Cp negative subjects within day 16-19. Conclusion: The optimised *3C-urea breath test using the 30 ,tine ~ a t i o n rate is not only highly sensitive, specific, and less expensive than endoscopy, but also noninvesive. It appears to be ideally suited as endpoint in therapeutic trials. Preliminary results show an immediate therapeutic efficiency of CBS and a oonversion to Op negative values after combination with amoxycillin. Dept. of Clinical Pharmacology, Genrg-August-University, Robert-KochStr. 40, D3400 Goettingen, FRG.

AUTOMATED QUANTITATION OF PSORIATIC LESIONS THROUGH TRUE COLOR IMAGE PROCESSING M. Herbin, A. Venot, L. Dubertret, J.Y. Devaux, G. Strauch, and G. Feutren During clinical trials the severity of psoriatic lesions is usually quantified by the PASI score (Psoriasis Area and Severity Index). This score takes into account the erythema, scaling and infiltration severity and the surface of the lesion. These parameters are subjectively evaluated by Dermatologists using rough grading scales. We proved that the PASI coefficient of variation could be greater than 50~ so that we attempted to develop an automated score (AS) which is presented and evaluated in this work. During the clinical trial of ciclosporin in severe psoriatic forms 128 color digitized images (ROB system) were acquired from patient color slides taken in standardized conditions. These images were registered using an automated procedure based on a complex registration model (translation, rotation, magnification, and linear transformation of pixel values). An automated segmentation was carried out on each image in order to separate the healthy skin from the erythema and sealing regions. 52 image couples were first selected for building a new score based on erythema (redness quantitated from ROB pixel values), sealing (whiteness derived from saturation evaluation) and lesion surface. This score was validated using a second independent sample of 48 "image couples. AS and PASI respectively agreed in 7 1 % and 65 of cases with expert advices given in simple terms of improvement and aggravation.

OP 01.04

OP 02.01

PHARMACODYNAMIC EFFECT OF SHORT-ACTING NITROGLYCERIN: NON-INVASIVE EVALUATION BY A NEW SELF-MONITORING DEVICE

ANTIPYRINE AND INDOCYANINGREENCLEARANCE IN PATIENTS BEFORE AND AFTER LIVER RESECTION H. Heidemann, K. Hoffmann, R. Engemann* I . Medizinische und C h i r u r g . * - K l i n i k , C h r i s t i a n - A l b r e c h t s U n i v e r s i t ~ t K i e l , FRG

E. A. Sotaniemi and J. T. Lahtela Oral nitroglycerin (N) has been used as anti-anginal agent for more than 100 years. The onset of action of N is rapid (1-2 min) and dependent on the absorption of the parent drug into the circulation. The anti-anginal potency of N compounds varies greatly and correlates poorly with the drug/metabolite plasma concentrations

(CPT 42: 273-277, 1987). There are methodological difficulties to measure th e response t o N t a b l e t s due to rapid onset o f a c t i o n . We evaluated the problem by measuring n o n - i n v a s i v e l y the pharmacodynamic e f f e c t o f two N t a b l e t s ( N i t r o R~ Orion, Finland and Nitromax R, Dumex, Danmark) by using a new self-monitoring~ computeruized device (Sport Tester PE 3000, Polar Electro, Kempele, Finland). Heart rate after sublinqual placebo~ Nitro and Nitromax was recorded in 10 healthy subjects and 10 patients with ischemie heart disease. The onset of action began after I min and reached its maximum within 3 min (volunteers) and 3.5 min (patients). Maximal increase was higher after Nitromax than Nitro. Subjects on betablockers has a smaller increase in heart rate than other patients or volunteers. In both groups placebo had no significant effect on heart rate. In vitro disintergartion time was more rapid with Nitromax (<14.1+2.2 s) as compared to Nitro (79.1+26.7 s, p < 0.002). The hardness of the tablets was equal. The onset and potency of action of N compounds seems to be related to the dissolving properties of the tablets. The microcomputer technology offers a reliable and non-invasive method to record

d i f f e r e n c e s between the onset o f a c t i o n o f s h o r t - a c t i n g N compounds. C l i n i c a l Research Unit. Department o f I n t e r n a l Medicine, U n i v e r s i t y o f Oulu and Deaconess H o s p i t a l , SF-90220 Oulu Finland

These results lead us to propose image processing as a new tool which permits to derive objective quantitative parameters during clinical trials in dermatology. IRT-ECLIMED, H6pital Cochin, 27 rue Fg St Jacques, 75674 PARIS Cedex 14, Inserm U312, Cr@teil and Laboratoires Sandoz, FRANCE.

Expanded lobectomies of the l i v e r are possible in cases of malignant tumors or s o l i t a r y metastases. I t was the purpose of t h i s study t o i n v e s t i g a t e regeneration phenomena of the l i v e r before and up to 6 month a f t e r the surgical i n t e r v e n t i o n . We measured the a n t i p y r i n e clearance (AP) as a parameter o f the cytochrom P450 system and the indocyaningreen clearance (ICG) as a parameter o f an a c t i v e b i l i a r y t r a n s p o r t system. A t o t a l of 9 p a t i e n t s (6 females, 3 males; median age 58 years) was studied. AP was measured by HPLC, ICG by photometer.

Anti pyri ne Cl(ml/min) Before After: 1 week 4 weeks 12 weeks 24 weeks

t I/2(h)

Indocyaningreen VD(1) Cl(ml/min) tl/2[min)

VD(I)

55.1-+24.8 10.3+- 4.3

41+-10 561+162

3.9+_I.2

3.1+-0.7

27.2t-I0.6" 26.~II.5 30.~13.2 29.~I0.6

4~ 3~ 3~ 3~

3.1+1.5 5.~I.9 3.5+--0.6 2.~0.6

2.4+_0.9 2.6+_0.6 3.0+I .6 2.0-+0.6

19.4+ 7.5 19.3-+13.3 14.7+-4.0 15.~ 4.1

8 488+-204 6 9519~187 8 462+ 81 6 458~_130

Conclusion: The a n t i p y r i n e clearance however not the indocyaningreen clearance is a useful parameter to judge l i v e r f u n c t i o n a f t e r surgical r e s e c t i o n . Regeneration phenomena do not take place over time. A dose reduction seems necessary f o r drugs t h a t are metabolized by the cytochrom P450 system of the l i v e r .

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OP 02.02

OP 02.04

EFFECT OF C Y S T A T H I O N I N E , A PHYSIOLOGICAL PRODRUG OF CYSTEINE, ON A C E T A M I N O P H E N INDUCED LIVER INJURY. T. Itoh, Y. Kitamura and Y. Kamisaki Department of Clinical Pharmacology, Tottori University School of Medicine, Yonago 683, Japan The h e p a t o p r o t e c t i v e e f f e c t of c y s t a t h i o n i n e as a physiological precursor of c y s t e i n e was examined in rodents. Liver injury was induced by the intraperitoneal (i.p.) injection of acetaminophen (5.0 mmol/kg). The mortality rates, serum alanine and aspartate aminotransferase activities and the histological analysis of the livers, which were obtained from alive mice, were adopted as markers of liver damages. Two administrations of cystathionine (5.0 mmol/kg, i.p.), one at 20 min before and one after the injection of acetaminophen, completely protected the liver against the acetaminophen-induced injury. Cystathionine prevented the acetaminophen-induced liver injury, restoring the glutathione level in the liver. Co-administration of taurine (5.0 mmol/kg) increased the hepatoprotective activities of cystathionine even at lower doses of cystathionine (0.18 and 0.55 mmol/kg). Propargylglycine, an inhibitor of cystathionase, abolished the hepatoprotective effects of cystathionine, although it could not interrupt the effect of cysteine. When cystathionine with or without taurine was administered i.p, into rats, the elimination kinetics of cystathionine from rat serum showed good fit to a one compartment model. Subsequent to the decrease of serum cystathionine, the concentration of c y s t e i n e was i n c r e a s e d , Coadministration of taurine did not change the half-life of cystathionine, but significantly increased the half-life of cysteine. This effect of taurine was also observed when cysteine was administered i.p. into rats. In conclusion, cystathionine had a hepatoprotective e f f e c t against acetaminophen-induced liver injury as a physiological prodrug of cysteine, and taurine potentiated the hepatoprotective effect of cystathionine,

GAGTROPROTECTIVE EFFECTS OF MILK PHOSPHOLIPID$, TOTAL L I PIDS AND BUTTER SERUM ON ETHANOL-INDUCED ULCER IN THE RAT A. P a r v i a i n e n , S. Salminen, D. Homer, H. Vapaatalo, Department o f Biomedical Sciences, U n i v e r s i t y o f Tampere, 83520 Tampere, V a l i o F i n n i s h C o - o p e r a t i v e D a i r i e ~ Assoc i a t i o n R. & D. Centre, 00180 H e l s i n k i , F i n l a n d .

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AIRINIST~TION QF ~ C ACID (ImCA) IN PAT]~RTS ~ BILTARY ~ (PBC) D(ES ~ ~ ~AIDCEJhtL%R F[RCTI(N E. Lotterer z , A. Stiehl2 , U. Foelsch 3 and J. Bircher I High ooncebtration.s of endogenous bile acids (HA) within hepatocytes in experimental cholestasis may disturb cellular function and thereby be toxic. In such situations administration of UDCA was found to be protective to hepatocytes (Kitani et el, Life Sci 30, 515, 1982). Consequently, euric/ment of the BA pool with UDCA may be therapeutically useful in PBC (Poupen et al., Lancet i, 834, 1987). In this disease, however, the consegnences of treatment With UDCA for hepatocyte function are as yet insufficiently known. Methods: Nine patients With PBC were treated with UDCA 15 mg/kg/day. Diagnoses were based on typical elinical and laboratory findings and on compatible histology. The gnlactose elimination capacity (GEC; Tygstrup, Scand J Clin Lab Invest 18, 118, 1966) and the aminopyrine breath test (ABT; Miotti, Digestion 39, 241, 1988) were applied as measures of the metabolic capacity of hepatocytes before and after 6 months of UDCA. Total bile acids were determined enzymatically, and individual bile acids by GLC. Results: Pruritus improved in all affected patients and no adverse drug reactions were recorded. Alkaline phes-phatase fell from 458 + SD: 157 to 260 + 100 U/1, r-glutamyl transferase from 223 • 173 to 77 • 74 U/I andG~T from 39-+ 17 to 24 • ii U/I (all p < 0.01). The GEC (4.7 + 1.4 versus 4.6 + 1.7 mg/min/kg, n.s.) and the ABT (0.60 + 0.33 versus 0.65 • 0.34 %, n.s.) remained unchanged after the 6 month period. Depending on the stage of the disease total plasma BA cononntration~s increased significantly, whereas endogenous BA (= total minus UDCA) were decreased in stages I -III and unchanged in stage IV. Coaclusions: The results confirm beneficial effects of UDCA on pruritus and biochemical abnormalities, whereas cellular function as expressed by GEC and ABT regained unchanged. The decrease of endogenous BA may be therapeutically useful, whereas increases in total BA-concentration in stage IV suggests caution as it may potentially be deleteri(xts. Divisions of Clinical Pharmacology I , and Gastroenterology and ~docrinology a , University of Gonttingen, Robert-Koch-Str. 40, D-3400 Goettingen and Division of Gastroenterology 2 , University of Heidelberg, Bergheimer Str. 58, D-6900 Heidelberg

SIMULTANEOUSBUFFERANDACIDCAPACITYDETERMINATIONSIN GASTRICJUICEWITH NILEPROST, A CYTOPROTECTIVEPROSTAGLANDIH Fuhrmei~ter. A. and Seifert. W. Up to now, plausible physiological medels for the concept of "cytoprotection" in pharmacology and pathophysiologyof the gastrointestinal tract have not been available. One concept of protecting the gastric mucosa is the increased buffer capacity (BC) of the surface epithelium. The current clinico-pharmacological methods are usually limited to confirming parameters classified by acidity or by buffer. This is why a method for the simultaneousdetermination of gastric acid and gastric buffer secretion has been developed. Under the exclusion of CO 2, the spontaneously outflowing gastric fluid was automaticallyset to pB 11 with HaOB.The influence of alkaline saliva was minimized by contieous aspiration. The subsequent extragastral backtitration with 1/10 n NCl leads to a titration curve with two turning points representing the equivalence points of the buffer components. The buffer concentration is found with the following fomula:

G a s t r i c u l c e r induced by a b s o l u t e ethanol was used t o examine the a b i l i t y o f m i l k p h o s p h o l i p i d s , b u t t e r serum and b u t t e r serum l i p i d s t o prevent u l c e r f o r m a t i o n . T h e i r o r a l doses ranged from 10 t o 4400 ~g P/kg c a l c u l a t e d as i n o r g a n i c phophorus. PGE2 (10-100 ~g/kg) and c i m e t i d i n e (50 mg/kg) were used as r e f e r e n c e compounds and 0.9% NaCl served as c o n t r o l . F o r t y - f i v e min a f t e r the a d m i n i s t r a t i o n o f the p r e p a r a t i ~ ons or the drugs the r a t s were given a b s o l u t e ethanol and were k i l l e d 60 min a f t e r t h a t . The stomachs were removed and the i n j u r i e s were analysed using a computerized p l a n i m e t r i c system c a l c u l a t i n g the r a t i o s between the l e s i o n areas and t o t a l stomach a r e a . The p h o s p h o l i p i d s and t o t a l l i p i d s in doses o f 1600 pg P/kg and 4400 ~g P/kg and PGE2 in a dose o f 100 ~g/kg were c l e a r l y g a s t r o p r o t e c t i v e a g a i n s t e t h a n o l - i n d u c e d u l c e r (p
BC[mmol] =

(mlHCl2,~q~i,al:-rnlHCll,F~a~~176 mIs.apl,

The validation of the methodwith weighed quantities of NaHC03between0.I and 1.0 mml showed a coefficient of correlation of 0.99 (p:
COR~I~kTION BICARBONATE ~COV]~RY

12

o,.,

11. 1.0, 9 , 8 , ,7 . ,6 , ,6 , 4 . ,6 , 2 1 ) } [

t/

......

~1.4 l.a

~ .... I

If,

1

O.91 0.8

I I

'

I

.S 0.7

b u l f e r capacity: 1~ 20.49 mraoL/l 2:18.08 mmoUI m~oVI

= 0.6

0.5 0.4

9

~o.a ~0.2 B 0,1

I

O.2

0,4

0.6

O.e

1

1.2

1.4

1.6

I I

HCl n/lO (m])

introduced Bic~bonBte (retool)

Fla. 1 , Correlation between introduced Fla. 2. Titration curve of 1 ml of HCOU-and recovered buffer capacity; aIEalizedgastric juice by UCI n/1D conn=67. taining variable amountsof buffer. Dep. Humanpharmekologie I, Schering AG, MiUlerstr. 171, D-IO00Berlin 65

A 41

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INFLUENCE OF A NEW PGE2-DERIVATIVEON THE PEPTONEAND FOOD-STIMULATEDGASTRINSECRETIONOF THE

DIFFERENTIAL SENSITIVITY OF P450dbI SUBSTRATES TO INHIBITION BY Q U I N I D I N E IN MAN. J. Turgeon. C. Funck-Brentano, H. Pavlou, R.L. Woosley and D.M. Roden. Encainide (E) is O-dealkylated to O-desmethyl encainide (ODE) which is further metabolized to 3-methoxy O-desmethyl encainide (MODE). Both these steps cosegregate with the geneticallydetermined polymorphic metabolism of debrisoquine. Since quinidine (Q) has been shown to be a potent and selective inhibitor of cytochrome P450dbl, the isozyme responsible for this polymorphism, we have evaluated the pharmacokinetic consequences of combining E+Q. Seven extensive metabolizers (EMs) and 4 poor metabolizers (PMs) received E (60mg orally + 4.5mg 14C-E i.v. simultaneously) alone and again during low dose Q (50mg q6h x 2d) in random order. Q did not alter E disposition in PMs. In EMs, Q significantly (p<0.05) decreased E systemic clearance from 935+541 (+SD) ml/min to 190• ml/min, a value not significantly different of that in PMs (126• ml/min). However, the partial metabolic clearance to ODE+MODE (635+489 ml/min) was decreased >10-fold (48• ml/min; p<0.05) by Q in EMs but was still ~10 times higher than that in PMs (6.4• ml/min; p<0.05). Low doses of Q (60mg q8h x 4d) were also administered to 3 EMs receiving chronic E therapy (50-75 mg/d). During E+Q in these patients, the areas under the plasma concentration-time curves for E and ODE were increased ~10- and ~2-fold respectively. As in the single dose study, no MODE was detectable in plasma. These data indicate that the O-dealkylation of E was partially inhibited by low dose Q while the metabolism of ODE to MODE was virtually completely inhibited. These results suggest differential sensitivity of P4500b1 substrates to inhibition by quinidine. The clinical consequences of this interaction requires further evaluation in patients. Departments of Medicine and Pharmacology, Vanderbilt University, Nashville, TN; and Department of Pharmacology, Georgetown University, Washington, DC, USA.

STOMACH

M. Mshler. W. Seifert and A. Fuhrmeister E2-type prostaglandinsinfluence gastric hormonesand acid secretion. The secretory stimulationby a protein meal is largely due to the antral gastrin release. NOCLOPROST ( N C L ) - a new PGE2-derivative - was investigatedin three studies for ant• effectsand espeeiallywith regard to a possibleinhibition of the stimulated gastrin release. 1st study: NCL as clathrate lyopkilisate was administeredto 80 healthymale volunteers in ascendingdose stages (n=4) in a dose range from 0.1lagto 500 ~g intragastral. Gastrin was stimulated after i h by peptone (200 ml of a 20% peptone solution) and after a further 3 h by a standard meal and determined for 9 h withgastrin-RIA.Results: NCL inhibits the peptone-stimulatedgastrin secretion already from 10 lag,but not the gastrin secretion after a standard meal. 2nd study: 6 voluteersreceived 250 lag NCL and 250 lag NCL clathrate solution. Gastrinwas stimulated as in stndy1 and determined at hourly intervals. In addition, the pH-valueswere measuredby intragastral glasselectrode. Results: the release of gastrin was reduced by NCL by max. 70%; the intragastral acid concentrationfell by 90% in comparisonto the pretreatment value. The two galenical formswere equivalent. 3rd study: 24 volunteersin 4 groups (n =6) received 50pgor 250 ~tgor 200 lag MISOPROSTOL 3 x dally for a period of 14 days. Gastrin was determined on 3 days (day 0, 5,12) in the 22-h profile.The intragastral pH-valueswere measuredat the same time. Results:The effect of NCL consistsprincipallyin the inhibitionof the peptone-stimuiatedgastrin release (4 h p. appl.). The effect is already clearly apparent after 50lagNCL and cannot be increased much further by raisingthe dosage.In contrast, after misoprostol,there is a sfightrise in the gastrinrelease. NCL reduced the number of pH-value < 2.5 measuredin the 12h period after peptone. A similar pH-reduction occurred under MISOPROSTOL. Conclusions:The ant• effect of NOCLOPROST is predominantly based on an inhibitionof the peptone-stimulatedgastrinrelease and on the acid secretion dependent on it, this already occurringat a dose of lqag/man. There is but tittle influenceon the release of gastrin throughthe regular ingestion of food. NOCLOPROSTthereforeprovidesrefiable protectionfrom inadequate acid stimulus. HumanpharmakologleI, ScheringAG, Miillerstr. 171, D-1000Berlin 65

OP 03.01 PRENYLAMINE ENANTIOMERCONCENTRATIONSAFTER SINGLE AND MULTIPLE DOSAGEIN MAN H. Spahn, Y. Gietl, H. Knauf(1) and E. Mutschler The two enantiomers of prenylamine (PA), a c h i r a l WHO-class V calcium antagonist, are known to have d i f f e r e n t pharmacological e f f e c t s with S-(+)-PA being a p o s i t i v e i n o t r o p i c and R-(-)-PA a negative i n o t r o p i c agent. Using reversed-phase HPLC (ODS, methanol/disodiumhydrogen phosphate s o l u t i o n ) a f t e r formation of the d i a s t e reomeric d e r i v a t i v e s with S-(+)-naphthylethyl isocyahate as c h i r a l d e r i v a t i z i n g agent, the pharmacokinetics of S- and R-PA was studied in eight healthy volunteers. They received a single 200 mg p.o. dose of racemic drug on day I, I00 mg b . i . d , f o r 9 days and another 200 mg dose on day I I . D i s t i n c t differences were found between the enantiomers. Plasma h a l f - l i v e s of S-PA were generally higher than those of R-PA. Average maximum plasma concentrations as well as AUC values of the R-enantiomer exceeded those of the S-form 5 times [Cmax(day I ) , 9.2 + 4.2 f o r S-PA and 50.7 + 20.6 ng/ml f o r R-P~; AUC(day- l ) , 164 + 71 f o r S-PA and 701 + 225 ng ml- h f o r R-PAl. UnboUnd f r a c t i o n s in plasma~as determined by u l t r a c e n t r i f u g a t i o n , were higher f o r S-PA. Only traces o f unchanged PA were excreted i n t o urine: 0.012 % S-PA and 0.014 % R-PA a f t e r a single 200 mg p.o. dose. The average renal clearance was 3 times higher f o r S- (4.0 + 5.2 ml/min a f t e r single dose) than f o r R-PA (1.3 + 1.4 ml/min). Upon acid-hydrolysis of urine samples -more S-prenylamine was formed, i n d i c a t i n g a s t e r e o s e l e c t i v e conjugation. Pharmakologisches I n s t i t u t f u r Naturwissenschaftler, Johann Wolfgang Goethe-Universit~t, Theodor-Stern-Kai 7, Geb. 75 A, D-600O Frankfurt/M. 70 and (1) St.-Bernward-Krankenhaus, TreibestraBe 9, D-3200 Hildesheim, F.R.G.

OP 03.03 STEREOSELECTIVE STUDIES ON P-450 HUMAN-2 (MEPHENYTOIN HYDROXYLASE) EXPRESSED IN YEAST CELLS A N D H U M A N LIVER. R. Kato, T. Yasumori and Y. Yamazoe Previously we have purified P-450 human-2 (mephenytoin hydroxylase) from human liver, isolated a cDNA clone and determined the cDNA sequence (J. Biochem., 102, 1075-1082, 1987). Moreover, we have demonstrated the expression of P-450 human-2 in yeast cells using a galactose-inducible expression system (Mol. Pharmacol., in press). The expressed P-450 human-2 in yeast cells showed high affinity for benzo(a)pyrene hydroxylation and S-mephenytoin 4-hydroxylation as that purified from human liver and showed 56K band by immunoblot analysis on SDS-PAGE. Both activities are strongly blocked by anti-P-450 human-2 IgG. The content of immunochemically determined P-450 human-2 content in human livers was correlated with the activity of Smephenytoin 4-hydroxylase, but not with S-mephenytoin N-demethylase. According to R/S ratio in mephenytoin 4hydroxylase in 19 human liver samples, the number of extensive metabolizer was 14 and poo r metabolizer was 5. The R/S ratio of the liver sample, from which P450 human-2 was isolated, was 0.193 (extensive metabolizer) and that of the expressed P-450 human-2 in yeast cells was about 0.2. These results indicates that P-450 human-2 is constitutively expressed as a major cytochrome P-450 for S-mephenytoin 4-hydroxylase and the P-450 expressed in yeast cells is real P-450 human-2 which is isolated from the extensive metabolizer. Department of Pharmacology, School of Medicine Keio University, Shinjuku, Shinanomachi 35 Tokyo, 160 Japan

A 42

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DOES RESTRICTION OF CAFFEINE INTAKE AFFECT MIXED FUNCTION OXIDASE ACTIVITY AND CAFFEINE METABOLISM M. Levy~ Y. Caraco and E. Z y l b e r - K a t z C a f f e i n e e l i m i n a t i o n k i n e t i c s were s t u d i e d in 11 h e a l t h y s u b j e c t s b e f o r e and f o l l o w i n g a r e s t r i c t i o n o f c a f f e i n e c o n t a i n i n g p r o d u c t s f o r a mean p e r i o d o f 25 d a y s . In 7 s u b j e c t s d e c r e a s e d c a f f e i n e m e t a b o l i s m was n o t e d . Alt o g e t h e r t h e mean d e c r e a s e o f t h e e l i m i n a t i o n c o n s t a n t ( k e l ) was 17% (0.0243) (p = 0 . 0 5 ) . This c h a n g e was more pronounced i n s u b j e c t s who i n i t i a l l y exhibited rapid caffeine clearance. At t h e same t i m e no c o n s i s t e n t e f f e c t could be o b s e r v e d on t h e h e p a t i c mined f u n c t i o n o x i d a s e (MFO) system activity as reflected by the 6~)-hydroxycortisol/17 hydroxycorticosteroid ratio or gamma-GTP blood levels. Ten of the subjects reported a decreased caffeine consumption following the restriction period. There was no concordance between ~ kel and the change in 6 (O)-OHF/17OHCS ratio or the change in habitual caffeine consumption. The individual variation in the effects of caffeine on the MFO and possibly on other target organs awaits further elucidation. Clinical Pharmacology Unit, Department of Medicine A Hadassah University Hospital, Jerusalem 91-120 Israel

PATHWAY-SELECTIVE SEX DIFFERENCES IN THE METABOLIC CLEARANCE OF PROPRANOLOL IN MAN. T. Walle, T.D. Cowart, U.K. Walle and E.C. Conradi. In a retrospective population study (Clin. Pharmacol. Ther. 38:509-518, 1985) i t was suggested that the clearance of propranolol was higher in men than in women, an observation that was novel for B-blocking drugs. In the present prospective study we examined this question in more d e t a i l , determining the clearance of propranolol through each of i t s three primary metabolic pathways in 9 young women and 15 age-matched men. No participants in the study were smokers or taking other drugs. Their diets were identical and the study was performed in a c l i n i c a l research f a c i l i ty. The propranolol doses consisted of a single 80 mg oral dose given simultaneously with a 0.I mg/kg i . v . dose of hexadeuterium-labeled drug. Plasma concentrations of the two propranolol forms were determined by GC/MS and the urinary excretion of metabolites by HPLC and GC/MS. The oral clearance of propranolol was s i g n i f i c a n t l y higher (67%, p
OP 03.05

OP 04.01

PHENPRoCOUMONKINETICS AND OXIDATIVE LIVER METABOLISM WITH AND WITHOUT PROBENECID A. Bammel, H. Mbnig, K.H.Zurborn, E.E.Ohnhaus, W. Kirch In a previous study i t could be demonstrated that the elimination of phenprocoumon (PPC) is accelerated by simultaneous administration of probenecid. The present study was therefore carried out in order to determine whether the observed shortening of elimination h a l f - l i f e might be due to an induction of the microsomal drug-metabol i z i n g enzyme system and/or to a diminished enterohepatic c i r c u l a t i o n of phenprocoumon. Probenecid-induced changes in the pharmacokinetics of phenprocoumon f o l lowing a single oral or intravenous dose (0.22 mg/kg b.w.) were investigated in 14 healthy volunteers. The urinary elimination of phenprocoumon and i t s glucuronide was reduced by more than 70 % (p<0.05). In contrast, the terminal h a l f - l i f e decreased by about 35 % (p<0.05). Peak concentrations after oral and intravenous administration were not diminished after coadministration of probenecid. As there were no s t a t i s t i c a l l y s i g n i f i c a n t differences between oral and intravenous administration, an impaired absorption and subsequently diminished enterohepatic c i r c u l a t i o n of PPC could be excluded. On the other hand after 7 days of probenecid-therapy there were s i g n i f i c a n t increases in antipyrine clearance of about 30 % (p<0.05) and in urinary excretion of 6Bhydroxycortisol by about 40 % (p
MODEL-INDEPENDENT KINETIC PARAMETERSOF METHYLPREDNISOLONE IN CHILDREN RECEIVING HIGH DOSE PULSE THERAPY S.Ito , H.Yoshioka ~ T.Oka and Y.Kusunoki The short-term parenteral use of methylprednisolone (MP) in high doses (MP pulse therapy) has been recommended for a v a r i e t y of diseases in children. However, associated l i v e r dysfunction and/or hypoalbuminemia may a l t e r the disposition of MP, and necessitate dose adjustment. In the present study, we chracterized kinetics of MP at high doses in children with either nephrotic syndrome (group A,n=6) or various non-renal diseases,which may p o t e n t i a l l y involve l i v e r (group B,n=9). The average values of model-independent parameters were s i m i l a r in the two groups(Table). Three patients exhibited apparent nonl i n e a r kinetics:one in the group A, two in the group B. The two patients had abnormal l i v e r function test values. These children showed two to three times greater dosenormalized AUCs than those with linear kinetics. Our results suggest that hypoalbuminemia per se does not a l t e r MP disposition at high-doses, and that more attention should be given to elucidate non-linear kinetics in terms of therapeutic and untoward effects of MP pulse therapy especially in children with diseases involving liver.

I. Medizinische K l i n i k , Christian-Albrechts-Universit~t, SchittenhelmstraBe 12, 2300 Kiel I, FRG

Table. Patients' data and model-independent parameters Group N Age (yr) A 6 9.3• B 9 8.4•

Weight (kg) 3113• 26.8•

Dose (mg/kg) 26.3• 26.2•

Albumin,serum (g/dl) 2.8• 3.5•

C1 Cl-u MRT Vdss AUC/Dose (llkg/h) (ml/kg/h) (hr) (I/kg) (kg.h/l) A 0.63• 37.1• 3.4• 2.0• 2.06• B 0.44• 27.4• 3.0• 1.3• 2.61• Mean• clearance;MRT,mean residence time; Vdss,velume of d i s t r i b u t i o n at steady state Department of Pediatrics, Asahikawa Medical College, Nishikagura 4-5-3-11, Asahikawa 078, JAPAN

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PHARMACOKINETICS OF CYCLOSPORIN IN VERY YOUNG CHILDREN STUDIED IN PREPARATION FOR RENAL TRANSPLANTATION. K.Hoppu, O.Koskimies, C.Holmberg and E.L.Hirvisalo.

PHARM~COKINETICS OF VIGABATRIN (GVG) IN CHILDREN WITH MEASUREMENT OF R(-) AND S(+) ENRNTIOMERS. G. OLIVE (I), E. REY (i), G. PONS (i), M.O.RICHI%RD (i), F.VAUZELLE (i), O.DULAC (2), P.d'RTHIS (i). (1)Dept.Clin.Pharmacol. (2)Neuropediatrie-Hop.St Vincent de Paul-Paris-France. G V G a specific irreversible inhibitor of GABA transaminase,is a new antlepileptic drug (phase III clinical study). Two groups of 6 epileptic children (I:lmonth-2y.o.;II:2-15y.o.) with u n c o n t r o l l e d seizures received a single 50 mg/kg oral dose. Blood samples (500ul) were collected at 0.5,1,2,3,6,9,12 and 24h after administration. The enantiomers R(-) and S(+) were determined by GC-MS. Cmax(mg/l) Cl(i/h/kg) Vd(i/kg) tl/2(h) I II I II I II I II R(-) 20.6 34.7 0.498 0.355 2.01 2.77 2.87 5.69 SD 5.7 12.1 0.110 0.083 0.68 1.19 1.03 2.86 S(+) 13.8 19.4 0.591 0.446 4.63 3.48 5.65 5.47 SD 4.5 6.9 0.165 0.103 1.12 1.23 1.52 1.93 Significant differences were observed b e t w e e n enantlomers on Cmax (S(+)R(-); p<0.01) in both groups and on tl/2 (S(+)>R(-); p<0.01) and Vd (S(+)>R(-); p<0.001) in group I. The R(-) tl/2 was linearly correlated to age (r=0.82; p<0.01). Significant differences were observed between groups : R(-) %1/2 was shorter and apparent plasma clearance larger in group I than in group II. The absence of significant difference in the GVG kinetic parameters between the two groups for the b i o l o g i c a l l y active enantiomer S(+) implies a similar dose regimen recommendation in 1 month to 15y.o.children.

Rapid elimination of cyclosporin has been previously described in children following renal transplantation, but the age groups studied have not been adequately defined. We studied 7 children (mean age: 2.07yrs; range 1.592.53) with congenital nephrosis of the Finnish type before renal transplantation to determine the appropriate individual dose. Cyclosporin (Sandimmun ~) was given as a single oral dose (10mg/kg) or as a 4-hour iv infusion (3mg/kg). Cyclosporin concentration was determined from whole blood samples taken at 0,1,2,3,4,6,9,12,16 and 24 h after the oral dose and before, in the middle of (2 h) and at the end of the iv infusion (4 h) and 0.5,1,2,3,6,9,12,16 and 24 h after it. Cyclosporin was determined with both specific and non-specific monoclonal radioimmunoassay ('Sandimmun Kit'). After the iv infusion the mean terminal tl~2 for cyclosporin was 5.1 h (range 2.8-8.8), CLo 11.6 ml/min/kg (7.1-23.5) and V 2.3 L/kg (1.3-4.6). The peak cyclosporin concentration after oral administration was attained in 1.9 h (1.03-2.03) and the mean absorption time was 3.6 h (0.8-11.6). The mean bioavailability was only 18% (range 5-33%), in two patients it was <10%. The mean ratio of non-specific to specific cyclosporin AUC was 1.4 (1.11.6) after iv and 2.1 (1.7-3.1) after oral dose (p<0.03). Fast elimination and poor bioavailability lead to high dose requirements in children of this age group. Extreme combination of both exist and cannot be predicted without pharmacokinetic studies. To attain a pre-dose blood cyclosporin level of 200-300 l.tg/L at steadystate we recommend an iv cyclosporin dose of 5 mg/kg/day; and an oral dose of 25 mg/kg/day. Due to the fast elimination rate, the daily dose should best be divided in 3 doses, A conversion of the iv dose should be made by a multiplication factor of 5. Children's Hospital, University of Helsinki, 00290 Helsinki, Finland.

OP 04.03

OP 04.05

D O S E - R E S P O N S E STUDY OF METOCLOPRRMIDE (M) IN GRSTROESOPHRGAL REFLUX (GER) IN INFANCY. G.PONS(1),J.F.DUHRMEL(2),M.GUILLOT(3),J.B.GOUYON(

RANDOMIZED, CROSS OVER COMPARISON OF IRON EXCRETION BETWEEN DESFERROXAMINE (DFO) AND THE NEW ORAL CHELATOR 1, 2 DIMETHYL-3-HYDROXYPYRID-4ONE (L1). Gideon Koren. Nancv F. Olivieri. Melvin H. Freedman. Patrick St. Louis, Richard Panicucei, Robert A. McClellan& DFO is currently the gold standard iron chelator in children with transfusional iron overload. However, the drug is neurotoxic, causing permanent hearing and visual loss in many children. Moreover, it is a very expensive drug and a nightly subcutaneous infusion costs $12,000 per patient annually. As important, toward their adolescence, children with thalassemia become noncompliant with the cumbersome and painful DFO schedule. We compared routine DFO therapy to a low dose of the new oral chelator 1, 2 dimethyl-3-hydroxypyrid-4-one (L1) synthesized in Toronto. Six thalassemics (age range 10-29) who were either neurotoxic or noncompliant with routine DFO served as their own control for the comparison. They were randomized to receive first DFO (50 mg/kg/day x 8 h for 3 days) or L1 (50 mg/kg q 8h for 3 days), one month apart at similar hemoglobin levels. Over the 3 day study and one day washout, urinary iron excretion was 98+67 mg (x~+SD) with DFO and 56-+20 mg with L1. Iron excretion was superior with L1 in 1 patient, was comparable with L1 and DFO in 2 patients, and was superior with DFO in 3 patients. In these latter patients, higher doses of L1 will be tested before instituting chronic therapy with the drug. In an additional 2 patients, iron excretion with L1 exceeded that with DFO historical control by 37% and 130%. The new oral chelator was comparable to DFO in urine excretion if Ca ++, Mg ++, Po4 -3 and Cu ++. None of the children experienced adverse effects attributed to Lt; one patient had nausea and Vomiting with both modalities. The cost of LI production was 1% that of DFO. We conclude that iron excretion with the new oral chelator L1 is comparable to DFO. Longitudinal studies are in progress to assess optimal dose and long term efficacy and safety of the drug. Division of Clinical Pharmacology, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada, M5G 1X8

4),Ph.d'ATHIS(4),M.O.RICHRRD(1),E.REY(1),C.MORAN( I),D.BOUGLE(2),E.BELLISSANT(1),Ph.EMENT(5) J.BADOUAL(1) and G.OLIVE(1). Twenty four 1 to 18 month old infants referred to 4 centers for suspected GER, whose esophagal pH was recorded over a 6-hour period following a standard formula meal at 9 to I0 a.m. (H0-day i) and fulfilling the criteria of more than 5% of time esophagal pH was <4 (HI to H6), entered double-blind p l a c e b o - c o n t r o l l e d dose-response trial of (M). 24h later the procedure was repeated after a single oral dose of (M) or placebo solution (day 2). Patients were randomly assigned to receive either placebo or 0.1,0.2,0,4 mg/kg (M), 30 min before the formula meal (n=6/group). (M) plasma concentration was m e a s u r e d lh after dosing (C lh). On day i, the time of esophagal pH<4, and 5 other parameters were not significantly different in the treatment groups. On day 2, time pH<4 (m(SD)) decreases from 33(13) to 30(33), 39(27) to 36(47), 42(15) to 18(13) and 48(25) to 31(46) min in placebo, 0.i, 0.2, 0.4mg/kg (M) groups respectively. Possibly due to the large interindlvidual variability, no significant differences in parameters were observed between the different groups, but there is a tendency for most of them to be improved in 0.2 mg/kg (M) group. None of the parameters correlates with either (M) doses or the C lb. No side effects were reported. A similar study should be performed after repeated dosing regimen. (1)Dpt Pharmacol Clln,Hop St Vincent de Paul, 74Av.Denfert Rochereau Paris 14-F. (2)CHRU Caen, (3)CHG Lisleux, (4)CHRU Dijon, (5)Lab. Delagrang e Paris - France.

A 44

OP 04.06

OP 05.02

METHIONYL GROWTH HORMONE PHARMACOKINETICS IN CHILDREN WITH IDIOPATHIC GROWTH HORMONE DEFICIENCY. G.L. Kearns, S.F. Kemp and J.P. Frindik Adult studies have reported mean elimination t89values of between 0.42 and 1.3 hr for [125I] human growth hormone (GH) and endogenous GH, respectively. Although methionyl growth hormone (hGH) has been used since 1985, little is known about its pharmacokinetics (PK) in children. We determined PK parameters for hGH in 12 children (I female; 12.4• yr; 31.2• kg; 135.8• cm) after a single SUBQ injection (Pre), and after 4 weeks (Post) of therapy. All had idiopathic GH deficiency documented by plasma GH < i0 ng/ml following standard provocative tests. Subjects received 0.3 mg/kg/week of hGH; 6 received this dose divided 3 times weekly and 6 with the dose divided into daily injections. Repeated blood samples (n=14) were obtained after dosing and hGH was quantitated by im~nunoradiometric assay. Plasma concentration vs. time data were curve fit using a WLS algorithm which enabled calculation of the following parameters: ......................................................... Tmax (hr) Cmax(ng/ml) CL(L/hr/kg) VDss(L/kg) Pre 4.5• 33.3• 0.27• 1.4• Post 3.4• 35.5• 0.46• 1.8• ......................................................... The mean apparent absorption and elimination t89for hGH was 2.0 and 4.9 hr, and 1.5 and 4.2 hr for the Pre and Post evaluations, respectively. The PK parameters were not significantly different between Pre and Post evaluations, or between patients receiving hGH daiIy or 3 times per week. A linear correlation (r=0.93; p<0.001) between hGH dose and AUC supported dose-independent kinetics. The elimination t89for hGH in our subjects was much greater than previously reported and in part, may be due to prolonged absorption of hGH following SUBQ dosing. Variations in dosing and/or multiple dosing do not appear to alter the PK of hGH in children. Divisions of Pediatric Clinical Pharmacology and Endocrinology, Arkansas Children's Hospital, Little Rock, AR 72202, USA

P R O S P E C T I V E S T U D Y OF H O S P I T A L I Z E D P A T I E N T S P R E S E N T I N G A L I V E R D I S E A S E : C O M P A R I S O N OF B I O L O G I C A L P A T T E R N S , E V O L U T I O N A N D D R U G USE A C C O R D I N G TO THE DISEASE E T I O L O G Y

J.C. PERE, G. SALAME, B. BEGAUD. F. HARAMBURU Between 1988 February 15 and October 31,340 inpatients from 12 departments of medicine presented a non-lithiasic non-tumoral hepatitis. 316 answered a questionary about personal habits (alcohol, tobacco, nu~ements) and drug consumption. This study describes the symptomatological and evolutive patterns of the different etiologies, and evaluates the influence of drug use on diagnosis and prognosis. Each patient used an average of 5,7 different drugs, the number of which varied with patients habits (alcohol, tobacco), with age and medical antecedents and with the final diagnosis. Non-narcotic analgesics and non-steroidal anti-inflammatory drugs, anxiolytics, antibiotics and multivitamins are the most used classes of drugs. AVERAGENUMBER OF DRUGS USED ACCORDINGTO AGE AND ETIOLOGY

ALCOHOLICHEPATITIS CIRRHOSIS UNDETERMINED DRUGINDUCED CHRONICHEPATITIS VIRAL HEPATITIS CARDIACLIVER GENERAL DISEASE

< 35 years

35 - 50

50 - 65

> 65

aU

2,6 6,5 6,1 6,8 7,3 4,5

2,6 3,9 4,7 t5,7 5 7

3 4,2 5,6 8,3 7 5 7 6

6 6,2 7,9 11,1 5,5 6,5 9 7,3

2,75 * 4,77 6,6 10,44" 6,36 5,53 8,38 7,1

-

8,5

5

ALL 5,2 4,4 5,1 7,8 CENTRE DE PHARMACOVIGILANCE DE BORDEAUX HOPITAL PELLEGRIN - ZONE NORD Bat 1 A 33076 BORDEAUX-CEDEX FRANCE

5,71

OP 05.01

OP 05.03

DRUG RELATED HOSPITALIZATIONS IN A MEDICAL WARD. A HIGH-INTENSITY STUDY. J. Hallas~ B. Harvald, L.F. Gram, E. Gs K. Bresen and T. Haghfelt Three-hundred and t h i r t y t h r e e consecutive p a t i e n t s in a general medical ward were evaluated in a h i g h - i n t e n s i t y m o n i t o r i n g o f drug events as cause o f h o s p i t a l i z a t i o n s . Considering the d e f i n i t e and probable drug events, we found 10.8~ (95~ confidence l i m i t s : 7.7-14.6 %) o f a l l admissions to be drug r e l a t e d h o s p i t a l i z a t i o n s (DRN). Of these, 8.1~ were adverse drug r e a c t i o n s and 2.7~ were t h e r a p e u t i c f a i l u r e s due to too low e f f e c t i v e dose. We found 2.4~ o f the admissions to be caused by e r r o r s in p r e s c r i p t i o n and a f u r t h e r 3.9~ that could probably have been avoided by an a p p r o p r i a t e e f f o r t from the h e a l t h s e r v i c e . The p a t i e n t s admitted because o f a drug event took s i g n i f i c a n t l y more drugs than o t h e r s , also when drug non-users were excluded. Other, non-significant c h a r a c t e r i s t i c s o f drug r e l a t e d h o s p i t a l i z a t i o n are o l d e r age, female sex, s h o r t e r d u r a t i o n of sSay and drug therapy e s t a b l i s h e d by h o s p i t a l d o c t o r . However, the distribution o f the a v o i d a b l e drug events compared to that o f the doctors r e s p o n s i b l e f o r the drug treatment point to the primary s e c t o r as the a p p r o p r i a t e t a r 9 e t f o r an i n t e r v e n t i o n . Judged by the sources of the i n f o r m a t i o n that ted to the suspicion o f a drug event and what was necessary f o r o full evaluation, a good estimate o f a DRH-rate should m i n i m a l l y be based on 1) an a c t i v e data c o l l e c t i o n by a qualified h e a l t h s e r v i c e worker, 2) r o u t i n e correspondence w i t h the p a t i e n t ' s GP in cases o f a DRH. This study was part o f a l a r g e program aiming at 2000 admissions covering the whole f i e l d of i n t e r n a l medicine. Department o f C l i n i c a l Pharmacology, Odense U n i v e r s i t y , J.B. Winslews Vej 19, DK-5000 Odense C.

INCREASED D I G O X I N T O X I C I T Y IN P A T I E N T S R E C E I V I N G A M I O D A R O N E (A), VERAPAMIL (V) OR QUINIDINE (Q). A.Mordel, M.Modan and H.Halkin Digoxin toxicity, identif~ by predetermined c l i n i c a l a n d / o r E C G c r i t e r i a in 21/141 consecutive i n p a t i e n t s , m e a n age (! SD) 7 2 . 2 • receiv i n g d i g o x i n , b y a n o b s e r v e r b l i n d e d as to c o n c u r r e n t m e d i c a t i o n s , was c o n f i r m e d b y r e s o l u t i o n of signs and s y m p t o m s a f t e r d i g o x i n was discontin u e d in 16/141 (11.3%). R a t e s of t o x i c i t y were 11/40 (27.5%) in p a t i e n t s o n c o n c u r r e n t A, V or Q, v e r s u s 5/101 (4.9%) in t h o s e n o t o n the a n t i arrhythmics (p<0.001). The two g r o u p s w e r e s i m i lar w i t h r e s p e c t to age, sex, BSA, creatinine clearance (49.0 • versus 45.0!23.0 ml/min) p l a s m a N a a n d K, u n d e r l y i n g c a r d i a c c o n d i t i o n a n d d a i l y d o s e of d i g o x i n ( 0 . 1 9 9 1 0 . 0 6 5 vs. 0 . 2 1 7 !0.116 mg respectively). H o w e v e r in the AVQ group s e r u m d i g o x i n was 37.7% h i g h e r (1.46!0.86 vs. 1 . 0 6 + 0 . 8 0 ng/ml, p<0/01) while estimated fractional digoxin plasma clearance was 43.5% lower (71.1+56.2 versus 102.1!89.5 ml/min respectively, p2.0 n g / m l the r a t e s w e r e s i m i l a r (7/11 a n d 4/8 r e s p e c t i v e l y ) . W e c o n c lude that k i n e t i c i n t e r a c t i o n s of d i g o x i n w i t h A, V or Q, s i g n i f i c a n t l y e l e v a t e s e r u m d i g o x i n l e v e l a n d the o v e r a l l r a t e of d i g i t a l i s t o x i c i t y in the elderly. A, V o r Q m a y a l s o e n h a n c e the r i s k o f digitalis t o x i c i t y at s u p p o s e d l y n o n t o x i c serum d i g o x i n levels. Department of Medicine, Clinical Pharmacology U n i t a n d B i o m e t r y Unit, S h e b a M e d i c a l Center, Tel A v i v U n i v e r s i t y S c h o o l of M e d i c i n e , Tel H a s h o m e r 52621, Israel.

A 45

OP 05.04

OP 05.06

DO P R E S Y N A P T I C A L P H A - 2 A G O N I S T S H A V E S L I G H T E R CNS S I D E E F F E C T S T H A N P O S T S Y N A P T I C A G O N I S T S ? A COMPARISON OF MOXONIDINE AND CLONIDINE B. D i e t r i c h a n d W.M. H e r r m a n n

S A F E T Y P R O F I L E OF ANTIRHEUMATICS IN L O N G T E R M A D M I N I S T R A T I O N (SPALA): FIRST YEAR EXPERIENCE OF AN INTENSIVE MONITORING S Y S T E M F O R N S A I D S M. K u r o w s k i *

T h e use of a l p h a - 2 a g o n i s t s such as c l o n i d i n e in the t r e a t m e n t of h y p e r t e n s i o n is o f t e n i m p a i r e d by a d v e r s e e f f e c t s as s e d a t i o n a n d d r y mouth. Moxonidine is a new substance that, unlike clonidine, stimulates mainly presynaptic alpha-2 receptors. C l o n i d i n e ' s s e d a t i v e e f f e c t is ass u m e d t o be c o u p l e d to the p o s t s y n a p t i c a l p h a - 2 r e c e p t o r s . T h e q u e s t i o n w h e t h e r m o x o n i d i n e induces slighter sedation than clonidine was e x a m i n e d in a c o n t r o l l e d d o u b l e - b l i n d r a n d o m i z e d study performed in a t h r e e f o l d c r o s s o v e r design. S u b j e c t s w e r e 24 h e a l t h y n o r m o t e n s i v e m e n a g e d 3 0 - 4 9 years. T h e y w e r e g i v e n a s i n g l e dose of e i t h e r 0.3 m g m o x o n i d i n e , 0.3 m g c l o n i d i n e , or p l a c e b o . The d r u g ' s p o t e n t i a l s e d a t i v e e f f e c t w a s t e s t e d o n t w o levels: f u n c t i o n a l n e u r o p h y s i o l o g i c a l level w i t h the p h a r m a e o - E E G and p s y chological performance l e v e l w i t h the 3 0 - m i n P a u l i test. A s p e c t s o f w e l l - b e i n g and m o o d w e r e a l s o e x a m i n e d w i t h the E W L - E A a d j e c t i v e c h e c k list; subjects were questioned about adverse events. M e a s u r e m e n t s w e r e at 120 a n d 270 m i n p.a. B o t h a c t i v e s u b s t a n c e s s h o w e d a s e d a t i v e e f f e c t in the p h a r m a c o - E E G , but this was s t r o n g er u n d e r c l o n i d i n e . The two s u b s t a n c e s d i f f e r e d m a r k e d l y in the P a u i i test. P e r f o r m a n c e u n d e r c l o n i d i n e w a s m u c h l o w e r in the f i r s t 15 m i n compared with moxonidine. Along with other v a r i a b l e s a n a l y z e d on a d e s c r i p t i v e level, t h e s e results suggest t h a t m o x o n i d i n e has s l i g h t e r c e n t r a l n e r v o u s s i d e e f f e c t s than c l o n i d i n e .

As of April, 1988 for a p e r l o d of 2 y e a r s an expected total number of 30,000 - 40,000 inhospital and a m b u l a t o r y p a t i e n t s are m o n i t o r e d for a d v e r s e e v e n t s in 16 a m b u l a t o r y c a r e u n i t s and h o s p i t a l s for r h e u m a t i c ~ i s e a s e s in W e s t G e r m a n y (9), A u s t r l a (4) and S w i t z e r l a n d (3). For every patient, who receives an NSAID, anamnestic data including concurrent diseases and concomitant medication are recorded by physicians and nurses employed e x c l u s i v e l y for this task. The qualitative and quantitative distribus of a d v e r s e e v e n t s w i l l be a n a l y s e d and p r e s e n t e d for e v e r y NSAID and monitoring center by demographic data, indication and d u r a t i o n of t r e a t m e n t . ~,,~ January ~ ~=~ ~, ~ patients were r e g i s t e r e d ( a p p r o x i m a t e l y 70 % i n - h o s p i t a l and 30 % o u t - h o s p i t a l patients). Diagnoses pertained predominantly inflammtory diseases and degenerative rheumatic diseases (ratio 2:1). Among prescribed drugs various p r e p a r a t i o n s of diclofenac prevailed (42 %), followed by indcmetacin, acemetacin, ibuprofen, plroxlcam, ketoprofen, tenoxicam and naproxen. Event p r o f i l e s of the f i r s t y e a r w i l l be summarized and d i s c u s s e d for t h e s e drugs. * r e p o r t e d on b e h a l f of the S P A L A g r o u p I n s t i t u t f~r P h a r m a K o l o g i e , U n v e r s i t i t E r l a n g e n U n i v e r s i t ~ t s s t r a s s e 22, D-8520 Erlangen, FRG*

A F B K l i n i s c h e P h a r m a k o l o g i e G m b H Berlin, K u r f ~ r s t e n d a m m 217, i000 B e r l i n 15, FRG

OP 05.05

OP 06.01

IS THE BENZODIAZEPINE (BZD)-GABAA-RECEPTOR COMPLEX INVOLVED IN CNS-EFFECTS OF GYRASE INHIBITORS? E. Unseld, G. Ziegler, A. Gemeinhardt, U. JanSen and U. Klotz

V I T A M I N A (Retinol) ZIMBABWE

In about 1 to 2 % of patients adverse effects to the CNS such as headache, insomnia, psychotic reactions or convulsions have been reported with fluoroquinolones. It has been suggested that CNS excitation might be due to displacement of GABA from its central binding sites. We therefore tested the effects of ciprofloxacin (Cip), norfloxacin (Nor) and ofloxacin (Off) on the binding of flunitrazepam (3H-FNZ) to receptor membranes from rat brain. In a clinical study the action of Off on the EEG was investigated in 12 healthy volunteers. In this randomized, double-blind, cross-over study 400 mg of Ofl or placebo was infused for 0.5 h; 10 min later an intravenous dose of midazolem (0.075 mg/kg), the specific BZDantagonist flumazeniI (0.01 mg/kg) or placebo was added to evaluate whether or not the Off-Induced EEG changes (monitored for 3 h) could be modified by agents acting directly at the BZDGABAA-receptor complex.

During the acute life saving phase of treatment for protein energy malnutrition (PEM) vitamin A is administered. Some people reco~end that in areas of the world where PEM and vitamin A deficiencies abound retinol in oil should be administered to children every 3 to 6 months, depending on the age. It also is recommended that vitamin E should be administered since it apparently increases the efficacy of vitamin A and also protects against vitamin A toxicity by increasing storage in the liver. Marasmus and kwashiokor, severe forms of PEM, are quite common in zimbabwe and are one of the major causes of morbidity and mortality. Plasma analysis study carried out at two referral hospitals in Zimbabwe showed that 42% of malnourished children had vitamin A deficiency. The study revealed that a multi-vitamin syrup containing 2000 IU vitamin A was given routinely. A retrospective study at the hospitals of i00 cases of malnourished children showed that i00,000 IU vitamin A had been prescribed for only 8 of the children. The study brought out several issues that need to be addressed before periodic administration of retinol is recommended in Zimbabwe. These include the routine administration of sub-optimal doses of vitamin A, apparent lack of appreciation of vitamin A deficiency and exclusion of vitamin E from the essential drugs list. Vitamin A as a capsule containing 50,000 IU is on the essential drug list for zimbabwe.

In the absence (presence) of GABA (300 uM) all three gyrase inhibitors impaired BZD binding in a concentration-dependent manner; the corresponding IC 50-values were for Cip 717 (1450) uM, Nor 840 (1248) uM and Off 921 (1043) uM. In addition, 3Hflumazenil showed a maximal 32 % reduction of 14C-Ofl binding in concentrations lower than 20 uM, but could not further decrease binding at higher concentrations. The observed changes in the pharmeco-EEG indicated that Ofl had some CNS stimulating effects (e.g. decrease in slow frequencies, increase of 8-activity) which were slightly augmented by flumazenil. Coadministration of midazolam shifted the Off-induced EEG changes towards the typical BZD-like pattern. In conclusion, from our pharmacodynamic interaction study it appears likely that the CNS effects of fluoroquinolones are mediated by an involvement of the BZDGABAA-receptor complex. Supported by the Robert Bosch Foundation, Stuttgart. Dr. Margarete Fischer-Bosch-lnstitut ftlr Klinische Pharmakologie, Auerbachstr. 112, D-7000 Stuttgart 50 / FRG.

Chikuni

USE AND M A L N U T R I T I O N

IN

O, N y a z e m a N and S u l e m a n M I.

Department of Clinical Pharmacology, P O Box A178, Avondale, Harare, Zimbabwe.

A 46

OP 06.02

OP 06.04

ACE ACTIVITY IN EXPERIMENTAL SCHISTOSOMIASIS UNDER THE INFLUENCE OF PRAZIQUANTEL &/OR CAPTOPRIL:

PLASMODIUM F A L C I P A R U M : OF I S O L A T E S FROM A L I G A R H

M.T. Khayyal, S. Saleh, A.A. Metwally*, & M.R. Mahmoud*

Malaria due to Plasmodium falciparum represents a major health problem in India. This study was aimed to identify and isolate drug resistant strains of Plasmodium falciparum in and around Aligarh region of India. The drugs -used for sensitivity study were chloroquine and mondest hy lamodiaquine (MADQ) . Drug coated polystrene plates provided as a gift by Dr. Le Bras, Institut De Medicine et D' Epidemiologie Africaines et Tropicales were used in the test. Forty eight isolates of P. falciparum obtained from cases of malaria in Aligarh were tested. The semi-micro test technique of Le Bras & Deloron (Am. J. Trop. Med. Hyg., 32(3), 447, 1983) was applied. Chloroquine was used in the range of 25 nM/litre to 1600 nM/litre and M A D Q in the range of 10 nM/litre to 400 nM/litre Out of the for ty-eight isolates, five were found to be resistant to chloroquine but all were sensitive

H.M.Khan,

S. Botros*

Murine schistosomiasis is usually associated with hepatic granulomatous lesions together with high serum and granuloma ACE activity. Praziquantel (PRZ) which is known to reduce granuloma size was studied to show whether this effect is related to changes in ACE activity. Furthermore, csptopril was studied to show whether by inhibiting ACE activity, the drug could also affect granuloma size. PRZ, Captopril, and their combination led to significant reduction in liver granuloma size, and in ACE activity in serum and liver granuloma. However, in normal mice, captopril w a s shown to increase rather than decrease serum ACE. The decrease in ACE activity by PRZ was correlated with its curative effect in infected mice. However, in exp~rimental!y induced pulmonary granu!omata, the drug reduced granuloma size without affecting ACE activity of either serum or granuloma. It may be concluded that reduction in ACE activity may be beneficial as far as diminution of granuloma size is concerned, and irreSpective of whether there is an active infection or not. Captopril may thus be safely used in bilharziel infections without the risk of adversely affecting the granulomatous lesions.

to

H.Kumar,

DRUG SENSITIVITY REGION OE I N D I A .

A.A.Mahdi

and

S.

IN-VITRO

Ahmad

MADQ.

Department of Microbiology, J . N. Medical College, Aligarh Muslim University, A l i g a r h - 202 002. I n d i a .

Pharmacology Depts, Faculty of Pharmacy, Cairo University and *Theodor-Bilharz Inst., Embaba, Cairo

OP 06.05

OP 06.03 M.H~, M.I~i. FD/~IIR, H. I ~ , D.W.G.h~

S d ~ i s i,~ ~

H.M. ALI, T.ELST~IG,

in.t~c~ ~ .

is a ~j~r h~_~ ~ m~..z~, ~

~=~..~

~ 7 ~ .

cide) ~hich ~as ~ to be as effecti~ a m creeper t h ~ Biltrici~. we h ~ ~ c m t ~ d th~ ~ c ~

Bil1~i~

~

hi~-~r blood le~_Is at all t ~

with a larg~ ~

the differer~es %~re not .s~' t ~

w~

wi~ ~

.~s

(0-24 ho~rs)

- the curv~ (l~_I;)~

cide ~ , cant. ~

diet ~

~to-

to Di%~o-. y signifi-

~idm-dblv high le~is c~.l~zz~s~s

on s/milar ~

nao

In a field ~ 433 and 455 h~t/Er~tswith S.m~scri i n f e L ~ m~J.~:l Bi3.~ &D i s t c ~ _ r ~ ' ~ l y in a ~ sty,. Cure rates at 6 ~ m ~ s ~ r e at 99.5~ fcr beth treatrmnts a ~ 89.3% and 96.9% at 6 r ~ for Biltricic]e art1 D i % T f r ~

~ y .

we o~nzJ~ that 6bee a d j u s t , e may be r~s~d if is qi~en with local Sud~3ese diet an~ to . . p ~ s w l m o~unrz ~ li~: disa~se. Biltric~ ard Dislzs ~ s:jqal ~

c

effects; but with Bilt~ci~. f o l l ~ ~ hhses bidder bloo~ le~_Is, .%~l]~r aeses with this ~ran3

~ay ~ ~e same effects. ~ of M~dicge ard l ~ u ~ v thi~ersity of leartn~ P.O. B ~ 102 and D ~ of Clinic~l ~ ~ ' , Be/fast, ~ Irelard.

STUDIES ON EFFICACY, TOLE~ABILITY, CARDIOVASCULAR SAFETY AND KINETICS OF FANSIMEF- DURING CHEMOPROPHYLAXIS V. Navaratnam~ FANSIMEF ~ is a triple co~nbination containing mefloquine, sulphadoxine and pyrimethamine which has been used for the treatment particularly of multi-resistant fa]ciparum malaria. T h e objective of the study was to assess the efficacy, tolerability and cardiovascular safety of two different doses of FANSIMEFr with placebo. Methods: The study was a prospective double b]ind randomised procedure comparing 3 groups of subjects. Six subjects were randomly selected from each group for electrocardiogram studies. The studies were carried out over a period of 20 weeks. Exercise stress was measured using a bicycle ergometer, Blood plasma levels were analysed using established gas chromatographic or HPLC procedures. Results: It was found that even at the lower dose FANSIM"EF@ was completely effective in suppressing malaria parasitaemia. In general, both doses were well tolerated, however there was a five-fold reduction in the incidence of adverse drug reactions at the lower dose level in comparison to the high dose reqimen. No significant ECG changes, at rest and durin~ exercise were observed after administration of FANSIMEF at both low and high doses with the exception of one case, at the high dose, which showed transient bradycardia. The pharmacokinetics of the combination was studied and the steady state for pyrimethamine was achieved after 10-12 weeks, sulphadoxine 18-20 weeks and mefloquine 18 weeks. Conclusion: The study showed that the low dose of FANSiMEF ~ was adequate in providing protection for healthy non/semi immune persons in malarial areas, better tolerated with minimal adverse reactions and with no cardiovascular consequences. Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penan9, Malaysia

A 47

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ASYMPTOMATIC MALARIA PARASIT#ENIA IN AN ENDEMIG AREA OF

EFFECTS OF SINGLE DOSES OF A L P R A Z O L A M (0.75 mg), DIAZEPAM (i0 mg), R I T A N S E R I N (i0 mg) and PLACEBO, ON PSYCHOMOTOR PERFORMANCE, MEMORY, SLEEP AND CONFLICT TESTS, IN HIGH AND LOW ANXIOUS HEALTHY VOLUNTEERS. P.DANJOU,D.WAROT,L.LACOMBLEZ,P.BOUHOURS,A.J. PUECH. A possible m e c h a n i s m of action of benzodiazepines (BZD) is a decreased activity of serotoninergic systems. New anxiolytics affecting specifically 5HT pathways have been developed. The effects of Alprazolam (A), Diazepam (D), Ritanserin (R) and Placebo (P) were assessed in 23 healthy volunteers screened on Cattell Anxiety Scale. In the High Anxiety level group (HA) Cattell score was 46.27!3.25 (n = !i), and in the Low Anxiety group (LA) this score was 13.50!1.67 (n = 12).Each subject was given the four treatments at a two week interval, in a doubler blind balanced latin square design.The tests used were Critical Flicker Fusion (CFF), Choice Reaction Time (CRT), Paired Words test (PW), Visual Memory test (VM), Stroop Stress test, Visual Analogue Scales (VAS) and Electrodermogram (EDG) and were performed before and 2h30 after dosing . The only anxietyrelated difference was a decreased C F F v a l u e before treatment in the HA group (- 1.4 Hz). Both BZD decreased CFF , A increased CRT , A and D decreased visual memory , A d e c r e a s e d short term memory score , and both BZD increased sedation on self-rating scales.Ritanserin d e c r e a s e d CFF but did not m o d i f y neither CRT nor m e m o r y tests, self-assessment was unnaffected. All active treatments h e l p e d subjects to fall asleep. While the sedative effect of benzodiazepines could be evidenced b o t h on objective and subjective variables, the only test s i g n i f i c a n t l y affected by ritanserin was the CFF. This result needs further confirmation and explanation. D@partement de Pharmacologie, Hopital de la Salpitri~re, 4 7 B d de l'H6pital 75651 PARIS Cedex 13.

NIGERIA:

EFFECT OF PERIODIC MASS TREATMENT

Funmilayo 0. A d A Y I &

L.A~.SALAKO

Ij279 pupils attending 2 primary schools in a semi-urban area in South Western Nigeria took part in a series of studies to determine the status of asymptomatic malaria

p a r a s i t e i n f e c t i o n among school age c h i l d r e n , Thick finger~-prick blood films were obtained from each

p u p i l , stained w i t h G~lemsa s t a i n and examined microscop i c a l l y for presence and density of malmz~ia parasites. In one group (n=226] screened quarterly for 12 months, a

seasonal v a r i a t i o n o f the crude m l a r i a p a r a s i t e r a t e was observed w i t h the lowest r a t e , ~/0, i n January and the h i g h e s t , ?4@/0, i n July, S i m i l a r l y , the q u a r t e r l y conversion r a t e was lowestg 24%1 bstwaen A p r i l and July, Only I~/0 had no parasitaemia w h i l e 0,~/@ harboursd the p a r a s i t e throughout the period o f study, In another group, higher p a r a s i t e r a t e was found ~mong p u p i l s aged 5-7 [n=216) and 8-9 (n=244] than among the ~Froup aged 10 years and above (n=185). More than ?e/~ of the cases had a parasite density of 8~O00/ul and below~ and this was independent of age. Children in a third study were subdivided into 2 groups. In one group of 128 pupils~ only these with malaria parasitaemia were given t h e r a p e u t i c dose of ohloroquine phosphate w while all the pupils in the second group (n=181) were treated. Full sensitivity to chloroquine was observed; and parasitaemia did not reappear until after 21 days fallowing drug a~inistration in both the treated and the untreated groups. This study shewed that (i] in ir~-vivo tests of antimalarial drugs in this endemic area, a~'~-d--~y-ytest would be able to exclude re-infection and (ii) when parasite density is below 5~OOO/ul in f e b r i l e c h i l d r e n , a search f o r an

a l t e r n a t i v e a e t i o l o g y i s very i m p o r t a n t , Department o f Pharmacology, Ogun S t a t e U n i v e r s i t y Teaching H o s p i t a l , P, MIB, 2001 ! Segemu, N i g e r i a ,

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EFFECTS OF SINGLE ORAL DOSES OF BROMAZEPAM, BUSPIRONE, AND CLOBAZAM ON PERFORMANCE TASKS AND MEMORY M. B0urin, J.L. Auget, M.C. Colombel and C. Laronsse The effects on memory and psychomotor Performance and the subjective effects of three anxiolytic drugs (bromazepam 3 mg, buspirone I0 mg and clobazam I0 mg p.o.) have been evaluated in a double blind placebo-controlled, cross over study in 20 healthy volunteers. At each session, measurements were made prior, + 2 H and + 6 H after drug administration. The psychometric tests used in this study were the images test, the digit/symbol substitution test (DSST), choice reaction time (CRT) and critical fusion frequency (CFF). Free recall after 30 secondes in the + 2 N session was altered for the three drugs compared with placebo (p < 0,01) but in the + 6 H session only bromazepam showed a significant difference (p <0,01). The number of symbols reproduced by subjects during DSST was significantly decreased by bromazepam and buspirone when compared with placebo (p < 0,01) wether clobazam did not showed any difference with placebo. Analysis of variance for the four treatments showed no difference between them either at recognition time or motor response in CRT. None of t h e anxiolytic drugs altered the performance of subjects during CFF (except bromazepam at + 6 H thus clobazam increased performances).

EFFECTS OF BUSPIRONE A~D DIAZEPAM ON EXOGENOUS, N~SOGENOUS AND ENDOGENOUS COMPONENTS OF CEREBRAL EVOKED POTENTIALS IN HUMANS. M.J. Barbanoj, M. Martfn, E. Gorina, J. Torrent, F. Jane.

Conclusion : Benzodiazepines studied and buspiroae disturbed acquision phenomena or restitution of memory. However only bromazepam and buspirone significantly modified performance during DSST and they disturbed the recognition and processing of sensory data.

Departement de Pharmacologie Ciinique C.H.U. 44035~NANTES CEDEX FRANCE

Benzodiazepines (Bzd), despite their effectiveness in the treatment of anxiety disorders, disrupt information processing at different levels. Buspirone (B) is a new anxiolytic compound pharmacologically unrelated to Bzd which seems to be devoid of an objective sedative pattern in its central effects. The aim of this study was to evaluate the activity of anxiolytic equipotent doses of B and diazepam (D) on exogenous, mesogenous and endogenous components of cerebral evoked potentials. After a habituation session, single oral doses of B (15 mg) and D (15 mg) were administered in a randomized, cross-over (washout period: one week), double-blind fashion under placebo-controlled conditions to 16 healthy subjects of both sexes. At O, 90 and 180 minutes, brain stem auditory (BSA), LED-flash long latency (LFL) and P300 auditory oddball -2:8- (F3) evoked potentials were registered in standard -stimulation, recording and quantificationconditions. Furthermore, subjective reports were assessed by means of Visual Analogue Mood Scales, P.O.M.S. and EES-cheek lists. D produced a latency increase of p e a k V on BSA, an amplitude increase of PI00-PI50 complex (occipital), an amplitude decrease and latency increase of P200 and N270 (central) on LFL, as well as an amplitude decrease and latency increase of P3, when compared to placebo (P) and B, the latter not being different from P. However, although subjective assessments after D showed the greatest decrease in "activity" and increase of both "sleepyness" and a number of side-effects, B could also be differentiated from placebo in these self-reports. These results provide further evidence that the mechanisms of action of B and Bzd ly on different neurobiological basis. Dep Farmacologia i Psiquiatria, UAB. Farmacol Clin, Hosp Sant Pau. Av. M Claret, 167. 0gO25-Barcelona. Spain.

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C O R R E L A T I O N OF T H E EFFECTS A N D CONCENTRATIONS OF D I A Z E P A M (DZ) M E A S U R E D CHEMICALLY A N D BY R A D I O R E C E P T O R ASSAY (RRA) M.J.Mattila, M.E.Mattila and E.-L. Hirvisalo Slowed saccadic eye movements after oral single doses of D Z correlate to its plasma peak concentrations (P. Bittencourt et al., Brit. J. din. Pharmac. 12, 523, 1981). W e have related plasma D Z levels to its effects on complex skilled performances and subjective visual analogue (VAS) ratings in a double-blind crossover study with 12 healthy subjects. Plasma D Z was assayed chemically (GLC, HPLC) and by radioreceptor assay (RRA) (K. Aranko et al., Eur. J. Clin. PharmacoL 28, 559, 1985) and D Z effects were measured at 1.5, 3, 4.5 and 6 h post intake of 15 mg D Z in capsule. Objective tests were digit symbol substitution (DSS), flicker fusion (CFF), Maddox wing (MW), tracking error severity (TES), and cumulative choice reaction time (RT). Drowsiness, clumsiness, passiveness and g o o d / h a d performance were rated on VAS. The D Z responses refer to differences from baseline after D Z minus respective differences after placebo. DZ-induced decrement of CFF did not correlate to subjective effects while prolonged RTs and increased exophoria (MW) correlated to drowsiness and poor performance. Chemically assayed plasma D Z did not correlate to subjective effects while R R A assayed D Z did so at 3 h. Significant concentration/response correlations in objective tests were occasional, yet chemically assayed D Z correlated to lowered CFF at 1.5 h (r= 0.668), to increased TES at 3 h (r= 0.737), and to impaired DSS at 4.5 h (r=0.823). R R A data correlated negatively to prolonged R T s (r=0.644) and to subjective clumsiness (r=0.655) at 6 h. We conclude, that a) the concentration/effect correlation for D Z is not a rule in complex performance tests; b) chemically assayed D Z correlates better than R R A data to objective test performance; and c) lowered CFF is not necessarily an objective measure of subjective sedation. Department of Clinical Pharmacology, University of Helsinki, Paasikivenkatu 4, SF-00250, Finland.

ZK 112 119 A B-CARBOLINE ANXIOLYTIC: PHASE I SINGLE AND MULTIPLE DOSE STUDIES TO ESTABLISH SAFETY, TOLERABILITY AND D R U G EFFECTS. T. Duka, B. Schiitt, R. Dorow, S. McDonald*, W. Krause and K. Fichte. ZK 112 119 ( 4-(methoxymethyl)-6-(phenyimethoxy)-gH-pyrido[3,4-blindole-3carboxylic ac,d 1-methylethyl ester(9CI) ), a b-carboline with high affinity for the benzodiazepine receptors, has been shown to be a potent anxiolytic and anticonvulsant m animal models while lacking ataxiogenic effects. ZK 112119 was tested in healthy male subjects in two separate double-blind, placebo controlled studies. In the single dose study ZK 112119 was tested hi five dosage levels (ling, 5rag, 10rag,20rag,40rag).In the multiple dose studyZK112119 was given in four dosage levels (15rag, 30rag, 60mg, 90 mg/day) for seven days. On the day prior to treatment, on days 1 and 7 of the treatment (afternoon and evening dose) and on the two days followingtreatment placebo was given in single blind conditions. In each dosage level in both studies drug was given to 10 subjects (7:verum, 3:placebo). Safety and tolerability were evaluated by changes in vital signs, incidence and severity of adverse reactions and any evidence ofpathological function related to major organ systems. Drug effects were estimated utilizing a visual analog scale (poles: 'sleepy'-'alert')aud the digit symbol substitution task. The ph armacokinetics of single and multiple doses were also determined. ZK 112 119 was well tolerated. In the single dose study the most frequently reported side effects associated with ZKl12119 were dizziness, unsteady gait, and lack of concentration and they appeared to be dose related. A decrement in performance on the digit symbol substitution task was observed in the two high dosage groups, 20 mg and 40 rag. In the multiple dose study, the most frequently reported side effects during treatment days were tiredness, dizziness, unsteady goatand lack of concentration. Frequency and severityof these drug related effects decreased as treatment progressed. During follow-up (days 8 - 9) the most frequently reported side effects were tiredness, headache and in the 90 mg/d group insomnia. Evaluation of visual analog scale ratings did not reveal any changes consistent with the treatment. In the digit symbol substitution task a decrease in the number of correct answers was found under treatment with ZK 112 119which was dose dependent. No changes were found in errors of comission. There was a dose-proportional increase in Cmax and in AUC values. The terminal half-life of ZK 112 119 was in the range from 5 to 7 hours. It was not affected either by dose or by single versus multiple administrations. The phase I safety related findings with ZK 112119 are typical of other similarly acting, anxiolytic compounds, particularly bcnzodiazepines. None of the findings proinbited further exploration of the drug's therapeutic utility in anxiety disorders. Research laboratories, Schering AG, Postfach 650311, D-1000 Berlin 65, FRG *Sandoz Research Institut, E. Hanover, New Jersey, USA

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The influence of flumazenil (ANEXATE) on the symptoms of grade I - I I hepatic encephalopathy (without prior benzodiazepine medication)

EFFECTS OF ORAL AND INTRAVENOUS DOSES OF ZOLPIDEM ON QUANTITATIVE EEG. L. Court, S, Trocherie. M. Guillaume, Ph. Dan]ou, C. Dubruc and P.L, Morselll. A series of observations was carried out to evaluate possible differential effects of zolpidem when administered orally (PO) and by the intravenous (IV) route, as well as possible relationships with drug plasma concentrations. The harmonic analysis of the EEG and the Stanford Sleeping Scale (SSS) were used as assessment criteria. Observations were carried out on 12 fully informed, healthy male volunteers aged 22 to 38 years. The trial design was double blind with double placebo. During the first part of the study doses of 20 ~ P0, I0 mg IV and placebo were administered to the 12 subjects. Slx subjects then underwent two extra sessions receiving 5 mg IV and 5 ~ P0. EEG recordln@, SSS and blood sampllng were performed before (Time 0), i0, 20, 30, 45, 60, 90, 120, 180, 240 and 300 minutes after drug administration (8:00 am). On the whole, results indicated that, Indepentently of the route of administration and dose, EEG assessed sleep latency was similar after all zolpldem treatments, while sedation appeared earlier after IV administration. Harmonic analysis showed that zolpldem induced the following modifications : increased delta activity (2-4Hz) with a simultaneous decrease in alpha wave activity (8-10 and 10-12 Hz), both of which persisted up to 3 hours, and a transient increase in fast activity (20-30Hz) for up to 45 minutes. The conventional observation of EEG recordings showed that the fast activity was of low amplitude and not organized in spindles. All effects persisted lonser after P0 than after IV dosing. One hour after zolpidem administration plasma concentrations were similar after 5 mg IV or P0, while they were proportionally higher after i0 mg IV and 20 mg PO. These data confirm the rapid absorption and the Eood bloavailabillty of zolpidam, as well as its specific effect on the EEG. Centre de Recherche du Service de Sent4 des Arm4es 24, ave du Maquis de Grdsivaudan 38700 La Tronche France

Kretz, F.J., Tils, Ch., Matthes, H., Striebel, H.H. Department of Anesthesia, Medical Department, Steglitz Medical Center, Free University of Berlin Problem: The number of benzodiazepine-binding sites on the GABA-receptor and the a f f i n i t y of benzodiazepines with the receptor are increased in patients with hepatic encephalopathy (HE). Attempts to treat HE grade If-IV patients with flumazenil resulted in some cases in dramatic improvements. I t is the aim of the present study to c l a r i f y whether flumazenil has a positive influence on the symptoms of HE grade I - I I . Patients, materials and methods: In a placebo-controlled, randomized double-blind study, 30 patients with histologically confirmed l i v e r cirrhosis and HE grade l - I f received i . v . 0.007 mg/kg b.w. of flumazenil or a placebo. Neurophysioiogicai parameters as degree of consciousness and mood were assessed on the basis of visual analog scales (VAS), concentration power was registered with the help of the number-connection-test (NCT) before, and 5, 15, 30 and 60 minutes after application. Results: At the NCT, the test results of the assessment group showed significant improvement already after 5 minutes. The results were also significantly improved at the other times of examination. Significantly better test results were obtained in the placebo group after 15, 30 and 60 minutes. There were no definite improvements regarding vigilance and mood. Discussion: The improved test results of the NCT may be explained as exercise effects, No positive effect on the symptoms mentioned in HE patients was observed with the administered dosage of flumazenil.

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THE ANTICONVULSANT EFFICACY OF VINPOCETINE,

A COGNITION-

ENHANCING DRUG, IN KINDLING MODELS OF EPILEPSY

J. Schmidt Epilepsy is very often connected with the development of memory

disorders

and

mem0ry-disturbing serious

many

effects.

impairment

for

antiepileptic

drugs

Memory disturbances

epileptic

patients.

have

can be a Therefore,

substances with combined anticonvulsant and cognition-enhancing potency are of interest in development of drugs for treatment of epilepsy. Kindled seizures are well established and reasonable models relevant to aspects of human epilepsy and are widely used for characterizing potential antiepileptic drugs. Vinpocetine possesses in doses known to have cerebroprotective

and

memory-enhancing

vulsant properties and

electrically

Vinpocetine

is

potency

in chemically (amygdala,

more

cortex)

effective

marked

anticon-

(pentylenetetrazol kindled

against

PTZ)

seizures.

kindled

FTZ-

seizures and shows similar potency in amygdaloid and cortical kindled seizures.

These differences in the potency

may be clinically relevant since they suggest a different efficacy

against

generalized

and

Partial

(focal)

seizures. Vinp0cetine may he of potential interest in the treatment of special forms of epilepsy and epileptic brain dysfunction. Institute os Pharmacology and Toxicology,

Medical Academy

"Carl Gustav Carus", Lingnerplatz i, 8010 Dresden, GDR

NON-INVASIVE ASSESSMENT OF TOPICAL NON-STEROIDAL AND CORTICOSTEROIDAL ANTI-INFLAMMATORY DRUGS EFFECTS ON NONIMMUNOLOGICAL CONTACT URTICARIA L. Duteil, C. Queille, M. Poncet, J. Czernielewski A new model based on combination of laser Doppler velocimetry and methyl nicotinate induced skin inflammation has been used to evaluate the efficacy of six topically applied anti-inflammatory drugs (NSAID) (bufexamac, diclofenac, ibuprofen, indomethacin, phenylbutazone and niflumic acid) and three topically applied corticosteroids (clobetasol propionate, hydrocortisone, hydrocortisone-17-butyrate). The aim of this study was to compare, in an urticarial type inflammation, the activity of two pharmacological classes of drugs inhibiting prostaglandins biosynthesis by two different mechanisms of action. Drugs were commercialy available (excepted indomethaein) and were applied under occlusion during 4 hours to the forearms of sixteen healthy volunteers. Skin inflammation was induced by 1 mn applications of methyl nicotinate (3mM) at 30mn and again at 44h after removal of drugs. Each methyl nicotinate application was followed by skin blood flow recordings. NSAiD proved globally more effective than cortieostereids in this model. Diclofenac and indomethacin shewed a potent prolonged inhibitory effect. Different types of activity were observed in the corticosteroids group: a) At 30 mn, hydrocortisene and hydrocortisone butyrate moderately inhibited methyl nicotinate reactions whereas clobetasol propionate gave no detectable effects, b) At 44 hours, clobetasol propionate gave significant inhibition whereas hydrocortisone butyrate and hydrocortisone exhibited a weak or no inhibitory action at all. These pharmacodynamic discrepancies between eorticosteroids classes were discussed in terms of differences in vasoconstriction activity and retention power. In addition, detailed analysis of skin blood flow recordings and statistical calculations were performed. CENTRE INTERNATIONAL DE RECHERCHES DERMATOLOGIQUES (CIRD), Sophia Antipolis - 06565 VALBONNE (France)

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ANTI-INFLAMMATORY P R O P E R T I E S OF A N O V E L W O U N D HEALING AGENT, TETRACHLORODECAOXIDE (TCDO). J. M a t h i e u , M. Tissot, M. R o c h - A r v e i l l e r , J.-P. G i r o u d a n d K.-W. Stahl.

TOPICAL CORTICOSTEROIDS USAGE IN DERMATOLOGY R, Uppal, S. C. Sharma, S. R. Bhowmik, P. L, Sharma and S. Kaur. Prescribing of corticosteroids was studied in 200 patients attending the dermatology outpatients of the Nehru Hospital attached to the Postgraduate Institute of Medical Education & Research, Chandigarh. The auditing of written prescriptions was done randomly, Data with regard to potency, quantity, frequency, duration and site of application was collected and analysed. Potent topical steroids were commonly used in 86 (43%) patients. Quantity of topical steroids was mentioned in only 4% prescriptions, whereas frequency in 77%, site of application in 69% land duration was specified in 55s respectively, The importance of these parameters is discussed. ~uidelines regarding use of topical steroids are suggested. Departments of Clinical Pharmacology and Dermatology, Postgraduate Institute of Medical Education & Research, Chandigarh - 160012, India.

The w a t e r s o l u b l e t e t r a c h l o r o d e c a o x i d e (TCDO) w a s f i r s t s y n t h e s i s e d to p r o m o t e w o u n d h e a l i n g & treat venous ulcers without any additional antii n f e c t i o u s a g e n t s (Hinz et al. 1986). M o r e o v e r it has b e e n s h o w n t h a t T C D O e n h a n c e s m a c r o p h a g e phagocytosis (Woerly et al. 1986) a n d i n f l u e n c e s c e l l u l a r and h u m o r a l i m m u n i t y ( G i l l i s s e n et al. 1987). The h e a l i n g p r o c e s s is e x t r e m e l y c o m p l e x b u t the e a r l i e s t s t a g e is the d e v e l o p m e n t of an i n f l a m m a t o r y r e a c t i o n at the b e g i n n i n g of w h i c h p o l y morphonuclear l e u c o c y t e s (PMN) a n d e i c o s a n o i d rel e a s e are g r e a t l y i m p l i c a t e d . On the o t h e r h a n d e v e r y f u n c t i o n of P M N has b e e n r e p o r t e d to be i n f l u e n c e d by a n t i - i n f l a m m a t o r y drugs (Goldstein i~oo) T~ w a s t h u s of i n t e r e s t to t e s t the activ i t y of T C D O on some P M N f u n c t i o n s a n d on m e d i a tor r e l e a s e a f t e r i n d u c t i o n of an a c u t e n o n - s p e c i f i c i n f l a m m a t o r y r e a c t i o n . In a p r e v i o u s s t u d y ( R o c h - A r v e i l l e r & Stahl, 1987) we d e m o n s t r a t e d an i n h i b i t i o n of P M N m i g r a t i o n a n d P M N a c c u m u l a t i o n in i n f l a m m a t o r y e x u d a t e a f t e r t r e a t m e n t w i t h T C D O on the e v o l u t i o n of an a c u t e n o n - s p e c i fic i n f l a m m a t o r y r e a c t i o n , the r e l e a s e of 6 - k e t o PGF 1 & PGE2, & P M N o x i d a t i v e m e t a b o l i s m . C R S S A BP 8724, M a q u i s Tronche, France.

de G r & s i v a u d a n ,

38702

La

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EFFECT OF LYSINE CLONIXINATE ON 14C ARACHIDONIC ACID IN THE HUMAN ARTICULAR CARTILAGE A.Terragno,N.I.Ecke,A.R.De los Santos and N.A. Terragno Lysine Clonixinate is an orally active analgesic, clinically used for its efficacy and for the low incidence of gastrointestinal side effects.Human cartilage from patients undergoing hip surgery were incubated for 1 hr at 37oC in Krebs' solution with 14C arachidonic acid (AA),2 ~M final concentration,in the presence or absence of inhibitors of oxidative m e t a b o l i s m of AA:Lysine Clonixinate (50 pg/ml) or Indomethacin (3,4 pg/ ml).After acidic lipid extraction Prostaglandins (PGs),5-Hydroxyeicosatetraenoic acid (5-HETE) and AA were separated by thin-layer chromatography,identified using authentic standards and quantified by liquid scintillation counting. The analYSiS of AA derivatives showed that Lysine Clonixinate is a dual Cyclooxygenase and Lipoxygenase inhibitor:the total PGs were inhibited by 12% and the 5-Lipoxygenase product,5-HETE was inhibited by 42%.In contrast Indomethacin inhibited the Cyclooxygenase activity,total PGs synthesis decrease by 19% but the product of the 5-Lipoxygenase,5-HETE increased 21%.The mechanism by which Lysine Clonixinate,unlike other non-steroideal analgesic,antiinflammatory drugs, does not produce mucosal damage is not well established but it may be related to the capacity of Lysine Clonixinate to inhibit Lipoxygenase activity and consequent reduces the deleteriuos effects of leukotrienes on gastric mucosal blood flow. Inst.of Clin.and Exp.Pharmacol.,M.T.de Alvear 1980 (l122),Bs.As.,Argentina and Dep.of Pharmacol.,Med. School,U.B.A.,Bs.As.,Argentina

PRAVADOLINE M A L E A T E FOR POST-OPERATIVE ANALGESIA: A CLINICAL STUDY I. M. Minehart, S. N. Steen, M. S. Mok and V. Zelman Pravadoline m a l e a t e (Pm) (formerly WIN-490986) is a new non-opioid analgesic shown to have antinociceptive properties in animals. This blinded study (part of an 8-center investigation) consisted of the single dose oral administration of either 200, 400 or 800 mg Pm, or 650 mg acetaminophen (A) or A with 30 mg codeine phosphate (AC), or placebo (P). Pain intensity (PI) was scored as 3,2,1 or 0 for severe, moderate, mild or none; at baseline, 1/2 h and hourly for 6 h (unless remedication occurred). 120 patients, who underwent gynecologic surgical procedures, completed the study between 15 Nov 1986 and 28 Apr 1987. 58 patients had a baseline score of 3 and 62 a score of 2. 15 patients for each of the above had little or no pain relief in the first 2-3 h; of the remaining 43 and 47, respectively, 2/3 had a clear decrease in PI for 6 h and 1/3 for 4-5 h. Though the code was not available to us, the results are similar to those of the 8-center study (Grieco G et al. Am Soc clin Pharm Ther, 90th Annual Meeting, 8-10 March 1989, Nashville, TN, USA) in that there was a significant decrease for P compared to non-P with no difference between Pm, A and AC. No serious adverse effects were noted. Thus Pm appears to be a safe and effective analgesic for the relief of moderate to severe postoperative pain. Department of Anesthesiology, Ohio State University, College of Medicine, Columbus, 43210, USA

OH

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EFFECT OF LYSINE CLONIXINATE ON THE BIOSYNTHESIS OF PROSTAGLANDINS AND LIPOXYGENASE PRODUCTS N.A.Terragno,N.I.Ecke,A.R.De los Santos and A. Terragno Lysine Clonixinate (LC) is an orally active analgesic,clinically used for its efficacy and the low incidence of gastrointestinal (GI) mucosal damage.Evidence now exists that changes in prostanoids Synthesis in GI tract may underlie the pathogenesis of non-steroideal antiinflammatory drugs.We compared the effect of LC with Indomethacin (I) on Prostaglandins (PGs) synthesis and 5-Lipoxygenase (5-Lo) activity. Human samples from colonic and gastric mucosa were incubated 1 h at 37~ in Krebs' solution with 14C arachidonic acid (AA),2 ~M final concentration: control,in the presence of LC (50 pg/ml) or I (3,4 pg/ml).After acidic lipid extraction PGs, 5-Hydroxyeicosatetraenoic acid (5-HETE) and AA were separated,identified by thin-layer chromatography using authentic standards and quantified by liquid scintillation counting. Indomethacin showed in colonic and gastric mucosa 30% inhibition in total PGs synthesis concomitant with 15% i n c r e a s e in the 5-HETE synthesis.Lysine Clonixinate caused inhibition in total PGs synthesis,18% and 20% in colonic and gastric mucosa r e s p e c t i v e l y but inhibited the synthesis of 5HETE by 25%.We postulate that the lack of mucosal injury showed in previous c2inical studies by LC may be related to the capacity of the drug to block 5-Lo activity and leukotrienes formation. The possibility to modify the final products of the AA cascade by drugs constitutes one of the most important pharmacological advances in this area. inst. of Clin. and Exp. Pharmacol.,M.T.de Alveax 1980 (l122),Bs.As.,Argentina and Dep.of Pharmacol.,Med. School,U.B.A.,Bs.As.,Argentina.

SELECTIVE MEASUREMENT OF FAECAL PORPHYRINS: A NEW METHOD FOR DETECTION OF NSAID-INDUCED GASTROINTESTINAL BLEEDING. APPLICATION TO ACETYLSALICYLIC ACID (ASA) AND NABUMETONE (NAB). J.K.Boeijinga, P.M.M. van Haard A.van Vliet-Verbeek and A.F. Cohen. Non-steroidal antiinflammatory drugs (NSAID's) frequently induce damage to the gastrointestinal(GI) tract leading to gastric ulceration and bleeding. Methods for the detection of microscopic blood loss lack either selectivity or are not suitable for daily practice. In this study we measured the fecal excretion of deutero (DP) and pemptoporphyrin (PP) as markers of haemoglobin loss in the GI tract induced by two NSAID's with possible different gastrotoxic profiles. Eleven volunteers received ASA 800mg tid,NAB 1500rag nocte and 500 mg in the morning and placebo(PLAC) in a double blind randomised cross over study.Drugs were administered for 5 days with a 7 day washout. All faeces over the drug treatment period were collected and DP and PP measured with HPLC with fluorometric detection both in the faecal homoganate (FH) and a random sample (RS), according to Beukeveld et aI.,1987.DP and PP peaks were normalised against the Coproporphyrin I (a marker for intravascular haem turnover) HPLC peak. ASA increased the summed DP and PP excretion over the treatment period by (av95%CI) 416%(284-547) in the FH and by 399%(276-522) in the RS compared with PLAC. No significant differences between NAB and PLAC were seen. We conclude that this new method might be a valuable tool for monitoring GI damage induced by NSAID's. This study appears to confirm the relative lack of gastrotoxicity of NAB. Centre for Human Drug Research, Leiden, the Netherlands. Beukeveld,G.J.J.,Wolthers,B.G.,van Soons,J.J.M.,de Haan,T.H.,de Ruyter-Buitenhuis,L.W.,. van Soons R.H.F.(1987) Clin.Chem.33,2164-70.

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OP 08.08

OP 09.02

PHARMACOKINETICSOF PEN~AMIDINE (PM) AFTER INTRAVENOUS AND INHALED APPLICATION IN AIDS-PATIENTS

PHARMAKODYNAMICS AND -KINETICS OF CARTEOLOL AFTER A SINGLE ORAL DOSE IN MAN - EFFECT OF COMEDICATION WITH CIMETIDINE J. Sehloos*. T. N~u~en**. G. Sitzler m and O.-E. Brodde** Carteolol (CA) is a B-blocker with intrinsic activity and long duration of action which possibly is due to an active metabolite (8-OH-CA) with a longer half-life of ~ 17 h in comparison to the parent compound (tl/2=5-6h). We therefore investigated whether Cimetidine (CIM) could interfere with pharmacodynamies and -kinetics of CA. In two groups (each n:10) volunteers received I x 30 mg CA p.o. Or CA and for 11 days 800 mg/d of CIM. Cardiovascular responses to exercise were determined up to 8 days after administration of CA. From blood samples withdrawn in parallel the following variables were determined: Antagonistic activity by means of a B1-selective radioreceptor assay, density of ~-adrenoeeptors o n lymphocytes and the resp. cAMP-response to 10 ~mol/l isoprenaline. Exercise induced tachycardia was diminished maximally by 25 beats/min I h after CA administration. Between 48 and 72 h the increase in heart rate was half-maximally reduced and disappeared 7 days after administration of CA. Extent and time-course of effects were not influenced by CIM. Maximal B-antagonistic activity (40 x Ki) in plasma was detected 3 h after CA and declined to I x Ki 60 h after CA in accordance with cardiac effects. CIM only slightly increased antagonistic activity in plasma. Density of B2-adrenoceptors on lymphocytes and cAMP-response to isoprenaline stimulation were diminished by about 50% 48 h after CA. Both variables remained decreased as long as 8 d after intake of CA irrespective of CIM medication. In conclusion, CA has a long duration of ~-blocking effects which might be supported by the occurrence of an active metabolite. It can be assumed that the partial agonistic activity of both compounds is responsible for the long lasting down-regulation of B2-adrenoceptors. CIM is if at all of minor influence on the kinetics and dynamics of CA.

H.-F. V~hringer,

K. Arasteh,

R. Averdunk

Objective. Evaluation of pharmacokinetics and efficacy of PM after i.v. and inhaled application in treatment of pneumocystosis (PCP). Methods. 23 AIDS-patients (pts) with severe or mild episodes of PCP were treated with pentamidinc isethionate: 5 pts by i.v. infusion (4 mg/kg/day) over 14 days, i0 pts by daily inhalation of a 500 mg dose end 8 pts by a 600 mg dose over 21 days, respectively. The nebuliser system was Respigard II, pentamidine concentrations in plasma and urine mere determined by HPLC; ~he efficacy was appreciated on clinical data and pulmonary function test. Results. After i.v. application the plasma concentrations of PM mere 20 - BD rig/m1 at steady state, indicating s great volume of distribution of 80 Z 15 1/kg body weight. In the t~o inhaled groups plasma concentrations of PM 24 hrs after inhalation were mostly non detectable (detection limit < 2 ng/ml). In urine, the daily elimination of PM were 1500 - 3000 ~g in the i.v. group, 20 - 150 pg in the 300 mg inhaled group and I00 - 250 ~g in the 600 mg group, respectively. Thus, the urinary excretion of PM after infusion is at least 10 times higher than after inhalation. The efficacy of PM after aerosolized treatment could be established; the side effects after inhalation were cough, brenchospasm and metallic taste. Conclusion. I) PM aerosols may be an effective and nontoxic therapy of a mild PCP. 2) The unimportant side effects after inhalation correspond to mostly non detectable plasma concentraLions and nearly I0 times lower urinary excretions of PM than after i.v. application (actualized data ~131 be reported). Auguste-Viktoria-Hospital, lin (W), Germany

RubensstraBe 125, D-]O00 Ber-

*Z.Pharmakologie, J.W.Goethe-Universit~t,D-6000 Frankfurt/M **Med. Klinik & Poliklinik, Unlversit~t Essen, D-4300 Essen

OP 09.01 EVIDENCE OF A DIRECT PROTECTIVEEFFECT OF DILEVALOL ON THE ISOLATED ISCHAEMIC HEART W.G. Nayler ~~R.R)-(-)-2,hydroxy-5-(1-hydroxy-2-[(1-methyl3-phenylpropyl)amino] ethyl benzamine hydrochloride is an antihypertensive B-adrenoceptor antagonist with ~2-mediated vasodilator a c t i v i t y ; Unlike propranolol d i l e v a l o l increases aortic compliance (Watkins et a l , J. Cardiovasc. Pharm. 12,42,1988. The following experiments were undertaken to establish whether pretreatment with d i l e v a l o l protects the heart against ischaemia-reperfusion i n j u r y , as does propranolol. Isolated, spontaneously beating hearts from Sprague Dawley rats were used. Perfusion was in the Langendorff mode, at 37~ with Krebs-Henseleit (K-H) buffer. After e q u i l i b r a t i o n hearts were made glob a l l y ischaemic for 10 or 30 min and then reperfused. D i l e v a l o l - t r e a t e d hearts had d i l e v a l o l added i0 min before induction of ischaemia, and throughout reperfusion, to provide a f i n a l conc. of e i t h e r 3xlO -s or 1.5xlO-SM. Hearts were assayed for tissue Ca2+, adenosine triphosphate (ATP) and creatine phosphate (CP), reflow area and peak developed tension. Coronary e f f l u e n t was assayed for creatine kinase (CK). Pretreatment with d i l e v a l o l attenuated CK release (p
OP 09.03 REPETITION ~ND WITHDRAWAL OF ~-BLOCKERS AFFECTING NORADRENALINE LEVEL IN TISSUES D.Z.DAI Drug effect is likely different between a single and repeated doses. The lowering blood pressure of ~blockers is only the result from repeated rather than single medication. O n e o f the main pharmacological effects of ~-blockers is to block postsynaptic receptor (pc-R), however, it is conceivable that s o m e therapeutic effects may be deduced from acting on presynaptic receptor (pr-R). The NA level in tissues is taken as an index of prssynaptic effect by ~-blockers with varying properties as c a r d i o s e l e c t i v i t y and partial antagonism. Rats (n=6 e a c h ) w e r e medicated with propranolol (pro), bevantolol (bey), metoprolol (met), 12.5 mg/kg bid each, and pindolol (pin) 200 ug/kg hld, sc f o r 7 o r 9 d. NA in heart, & lung, spleen, adrenal or hypothalamus and urine were measured on d 0,1,2,3,6 and 1-3 d following cessation, The typical effect by propranolol is a c o mpensatory increase on d 1-2 continued by an adaptive decline on d 3-7 and a rebound following withdra~ wsl. The change in NA in relation to receptor is summarised as follows. Blocking R Repeated medication Withdrawal po-R pr-R compens.~ adapt.$ rebound pro + § § + + met pin

§

-

+/-

-

§ + @/The uptake and release of NA were measured in situ with pro. R e p e a t e d p r o increased both uptake and r e l e a s e rate and declined sharply on cessation. The NA released in heart was still above control on withdrawal while uptake is below control contirbuting to rebound phenomena in clinical settings. The presynaptic effect of ~ b l o c k e r s is marked and its cllnical significance is worth to consider. Research Division of Pharmacology, China Pharmaceutical University, Nanjing 210009, China.

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OP 09.06

EFFECT OF EXERCI3E AND 1] BLOCKIN6 THERAPY ON NOREPINEPHRINE AND I1.H.P.6. CIRCULATINO PROFILE IN HYPERTENSIYE PATIENTS. M.D.Drici, F.Le Coz, R.Garaffo, P.Lapalus, P.Morand, P.Jaillon.

TIME COURSE OF THE BETA-SYMPA~4ICOLYTIC ~ H~K)DYNAMIC ACTIVITY OF NEBIVDLOL IN COMPARISON TO ATENOLOL FOLL(YNING SINGLE (~AL DOSES

Plasma norepinephrine (PNE) levels appear to reflect sympathetic nervous system activity, but assay and physiological problems (such as variability under stress or circadian rythm) tend to limit their reliability. 3-methoxy- 4-phenylethylene glycol (MHPG) is one of the major metabolites of NE and its plasma determination could be an attractive alternative for monitoring sympathetic activity. Since no previous study evaluate its profile in moderate hypertension, the aim of this study was to determine NE and MHPG levels in hypertensive patients, at rest and during exercise, before and after B blockade. Methods: 28 patients (20 M, 8 F), with mild to moderate hypertension, aged 48+15, underwent submaximal bicycle exercise tests before and 3 h. after 1] blockade: each exercise test consisted in progressive effort stages (2nm,20 watts) until 85% of theoretical maximal heart rate was reached. Patients then received a single oral dose of the fl blocker dilevalol (200,400 or 600 rag) in a randomized double blind placebo controlled parallel group protocol. Venous blood was drawn in ice cold hepariaized tubes from antecubltal vein a) after 30 ton at supine rest, b) during the 100 W stage of exercise test and e) at the maximal level of exercise . NE and MHPG levels were determined with a specific assay (HPLC with electrochemical detection). Results: During control tests, mean NE levels increased from 1.73 +0.52 nm.l'lat rest to 8.01 • nm.l"1 at the maximal effort (p<0.01), as MHPG levels increased fromll.lS • nm.l-l(rest) to 17.5.0 • nm.l"1 (effort, p<0.01). NE plasma levels were correlated to those of M H I ~ both at rest and at exercise. After 13blockade, the resting NE levels increased from 2.32 +0.99 nm.l"1 to 12.42 • nm.l" 1 (p<0.01). The increases in NE levels during exercise were more important under 1] blocker (p<0.05) and linearly related to the dose ( p<0.01): + 4.05 nm.ls 1 under placebo; § 5.77 nm.l"1 after Dilevalol 200 rag; +9 nm.l-tafter D 400 mg and +15.54 nm.1-1 after D 600 rag. There was no significant variation in MHPG levels after 13 blockade, neither at rest (11.18+1.33 vs 12.65• rim.1"1) nor at exercise (17.50 • vs 17.28 • nm.l't). Conclusion:In untreated moderate hypertension MHPG levels at rest and exercise are correlated with PNE levels and could be used for monitoring sympathetic activity. However after 13blockade, MHPG plasma levels no more reflect PNE levels . The existence of a metabolization delay of NE in MHPG could explain these results.

M. Buschmann, D. Trenk, K.-U. Seller and E. J~hnchen Nebivolol is a new51-selective adrenoceptor antagonist with peripheral vasodilating properties. We investigated the extent and the time course of the B-sympatholytic activity of different doses of nebivolol (5,. i0, 15 and 20 mg) in comparison to 100 mg of atenolol in a placebocontrolled randomized manner in i0 healthy volunteers by use of repeated cycle ergometry. Exercise-induced tachycardia was reduced after nebivolol as well as after atenolol. Evaluation of the data for the highest individual work load for every subject revealed that the maximum reduction was 22.2 • 5.3 % after atenolol and 9.9 • 6.9 % (5 mg), 14.1 i 7.0 % (i0 mg), 16.5 • 8.0 % (15 mg) and 19.2 i 4.9 % (20 mg) following administration of nebivoioi. The areas under the effect vs. time curves (%'hr.) were used as an estimate of the effect per dose and were calculated as 376 i 217 for atenolol, whereas there is a dose-dependent increase following nebivolol (234 • 359 (5 mg), 442 i 307 (i0 mg), 506 • 283 (15 mg) and 572 • 272 (20 mg), respectively). Maximal reduction os the systolic blood pressure during exercise was 25.5 • 12.0 % after atenolol and 10.2 i 10.8 % (5 mg), 11.7 • 12.0 % (i0 mg), 15.2 + 10.3 % (15 mg) and 22.4 • 13.9 % (20 mg) after nebivolol. These results suggest that compared to the beta sympatholytic activity of i00 mg atenolol a dose of 30 mg of nebivolol exerts approximately the same maximal effect, while 5-10 mg of nebivolol produced almost the same total effect per dose. Abteilung for Klinische Pharmakologie, Rehabilitationszentrum, SHdring 15, D-7812 Bad Krozingen

Unit4 de Pharmacologie Clinique, HOpital Saint Antoine,184 rue du Faubourg Salnt-Antoine.75012 Paris, FRANCE

OP 09.05 CORRELATION OF PHARMACOKINETICS AND PHARMACODYNAMICS OF METOPOLOL AND ITS INTERACTION WITH A CHINESE TRADITIONal, MEDICINE JIANG Wen-De (CHIANG Wen-Teh), ZHANG Ying-Yang, CHEN WeiNa The PK properties and their correlation to PD of selective ~l-adrenoceptor blocking agent metopr~ol in Chinese remain unknown. Plasma concentrations of metopr~ol were measured in i0 volunteers by HPLO method after oral doses 50,75,100 mg of metoprdol. Five of them were given doses of DANSHEN chinese drug for fifteen days, and then the PK and PD study of l O 0 m g metopr~ol was repeated. In doses 50, 75, lOOmg, Tmam ranged from 1.2~ 0.3 nmol/L. The Cmax andAUC were dose dependent: Cmax 307.4~7.7, 448+ 20.5 and 905~40.3nmol/L; AUC 2514.7~1637, 3391~2310 and 4510• respectively. Vd ranged from 5.0 to 5.6L/kg. CL were 72.2• 77.9• and 81.3=37.3L/h. The t~ el showed an interindividual variation of about three-fold: T~ 2.47• 2.61• and 4.45• respectively. There was an early significant decrease in HR for 2 to 3 hrs. The mean values of HR reduction were 13.4+2.6, 18.7• 5.0 and 16.8~Ii.3%, linearly correlated to plasma concennrations. TheaSBPmax were 1.47• 1.44• and 1.56• and for~DBP from 3 to 9 hour were 0.83• 0.56• and 1.33 _+0.76kpa respectively. The blood pressure-lowering effects lag behind its HR-lowering effect. The delay for SBP reduction was one hour and for DBP reduction over two hours, suggesting differen~mechanisms responsible for HR-slowing and hypotensive action. STIs increased mainly in the lengthening of PEPI and increase of the ratio PEP/LVET without any alterations of QTc and QRS complex. When metopr~ol was used in combination with DANSHEN the PK and PD profile showed very little difference to those after a single administration of metoprolol, except the Tmax increased approximately 0.5h. Institute of Clinical Pharmacology, Shanghai Medical University, Shanghai 200032. The work was supported by AB HASSLE

OP 09.07 TISSUE P L A S M I N O G E N A C T I V A T O R A C T I V I T Y IN P L A S M A D U R I N G A D R E N A L I N E I N F U S I O N A N D M E N T A L STRESS: INFLUENCE OF M E T O P R O L O L TREATMENT. P. Hjemdahl, G. Olsson. P. T. Larsson. B. Angelin and B. W i m a n To investigate if sympatho-adrenal activation influences fibrinolytic activity in plasma, we examined effects o f mental stress (a colour w o r d conflict test; CWT) and i.v. adrenaline infusions on tissue plasminogen activator activity (t-PA; IU/ml) and plasminogen inhibitor acfivity.(PAI; arb. U/ml) in 10 bealthy males. Furthermore, effects o f metoprolol (200 m g sustained release once dally) or placebo (cross-over study) were investigated. C W T has been shown to cause marked cardio-renal sympathetic activation and peripheral vasodilatation. Low dose adrenaline causes similar vasodilatation, After 30 rain rest C W T (20 min) increased venous plasma adrenaline levels from 0.1-0.2 to 0.4 n M a n d heart rate by 29 bpm. After another 60 min o f rest adrenaline was infused (0.1 & 0.4 nmol/kg/min; 15 min at each dose level), w h i c h increases plasma adrenaline to 0.9 and 3.4 n M and heart rates b y 9 and 18 bpm. T - P A increased m a r g i n a l l y f r o m 0.11!-0.04 to 0.18_+0.04 (p<0.1) during C W T . Adrenaline increased t-PA dose-dependently f r o m 0.15_+0.03 to 0.38_+0.09 (p<0.01) and 1.17_-+0.22 (p<0.01). P A I w a s not altered b y C W T but w a s r e d u c e d f r o m 3.5_+0.8 to 1.3_-20.6 (p<0.01) b y high dose adrenaline. Cardiovascular responses to C W T and adrenaline during metoprolol treatment confirmed Bl-selectivity. Metoprolol enhanced the t-PA response to C W T but did not influence the r e s p o n s e to adrenaline. T - P A activity w a s inversely a n d PAI activity positively related to s e r u m triglyceride (TG) levels d u r i n g placebo. Metoprolol elevated T G and abolished these relationships. Thus, sympatho-adrenal activation increases fibrinolytic activity in h u m a n s . T h e m e c h a n i s m s i n v o l v e d r e m a i n to be e s t a b l i s h e d . P r e v i o u s l y n o t e d relationships between fibrinolysis a n d T G w e r e confirmed. Metoprolol tends to influence fibrinolysis positively a n d alters relationships between T G and flbrinolysis. Department o f Clinical Pharmacology, Karolinska Hospital, S-104 01 Stockholm, Sweden.

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OP 09.08

OP 10.02

MENTAL STRESS AND ADRENALINE INFUSION INCREASE PLATELET AGGREGABILITY IN VIVO BUT REDUCE ADP INDUCED PLATELET AGGREGABILITY IN VITRO. P. T. Larsson. P. Hiemdahl and G. Olsson.

THE RISK OF AGRANULOCYTOSIS DIPYRONE USE IN BULGARIA

Effects of mental stress (a colour word test; CWT) and adrenaline infusion (0.1 and 0.4 nmol/kg/min; 15 min at each level) on platelet aggregability were studied in 10 healthy males. Aggregability was assessed by a filtragometry technique (measuring platelet aggregates in continuously drawn venous blood), which reflects platelet aggregability in vivo, as well as by conventional ADP (adenosine-diphosphate) induced platelet aggregability in vitro. Venous plasma adrenaline increased from 0.1 to 0.4 nM during CWT and to 0.9 and 3.4 nM during adrenaline infusions. Heart rate increased by 29 bpm during CWT and by 9 and 18 bpm during adrenaline infusion. Platelet aggregablity in vivo increased by 36+12 % (p<0.05) during CWT and returned to basal levels before adrenaline infusion, i.e. 60 min later. Adrenaline infusion also increased aggregability in vivo, but only at the high dose level (38+8 %; p<0.05). Platelet sensitivity in vitro was reduced, as the ED50 for ADP increased from 1.4-+0.2 to 1.7_-/-0.2 ~M (p<0.05) during CWT, tended to remain elevated before adrenaline infusion (p<0.1) and was further increased to 2.2_+0.3 }.tM (p<0.05) after adrenaline infusion. Thus, sympatho-adrenal activation by mental stress or adrenaline infusion increases platelet aggregability in vivo (filtragometry measurements), but desensitizes platelets to ADP induced aggregation in vitro. The pro-aggregatory effect of mental stress in vivo is not explained by elevation of circulating adrenaline, as low dose adrenaline failed to replicate the effect of CWT. Conventional in vitro techniques may reflect alterations in platelet aggregability in vivo poorly. Department of Pharmacology, Karolinska Institute, S- 104 01 Stockholm, Sweden.

V.Vlahov,

IN RELATION

TO

N.Bacracheva

The investigation was carried out as a population-based case-control study. For the observation period of 5 years and 5 months / August 1982 - December 1987/, 21 cases of agranulocytosis were identified among the population in Sofia (I.i millions),giving a mean incidence rate of 3.52 cases per year per million. The use of dipyrone in the week before the onset of illness was compared between 18 cases of agranulo cytosis and 106 hospital controls.For dipyrone, the multivariate rate ration estimate adjusted for age,sex and use of other drugs was 1.7 (95/confidence interval of 0.4 - 7.3). The etiologic fraction amounted to 20.6%,which transla~ ted into an excess risk of 0.04 agranulocytosis cases per million users of dipyrone.Fo r the same observation period,the utilization of dipyrone (alone or in combination) by the population of Bulgaria increased from 23.9 to 36.7 defined daily dosis /i000 persons/day,whereas the incidence rate of agranulocytosis remained constant. The results suggest that Bulgaria belongs to the countries in which the use of dipyrone is not asa@ciated with a high risk of agronulocytosis~ | (JAMA,256, 1749-1757, 1986). Chair of Clin.Pharmacol.,Inst.of Pharmacol. Pharm, Bulgarian Medical Academy, 1040 Sofia.

OP 10.01

OP 10.03

OVERALL SAFETY OF FLURBIPROFEN (ANSAID | TABLETS): RESULTSFROM PREMARKETING TRIALS

O X I D A T I O N O F 0 P C - 8 2 1 2 T O A R E A C T I V E I N T E R M E D I A T E BY INFLUENZA VACCINE-ACTIVATED NEUTROPHILS : POSSIBLE RELATIONSHIP T O A G R A N U L O C Y r O S I S . J. P. U e t r e c h t . N. Zahid. a n d S. P. S v i e ~ e r a

O. I. Linet, L. F. Turner and C. D. Brooks Flurbiprofen (F) is a non-steroidal a n t i - i n f l a m m a t o r y drug (NSAID) recently approved in the USA for treatment of rheumatoid arthritis and osteoarthritis. The safety of F (N = 2820) was compared to aspirin (ASA, N=626), ibuprofen (IBU, N=284) and placebo (PLA, N=274). Studies lasted from 7-730 days and included other indications than specified above. The active agents were studied at equi-effective doses. All adverse reactions {ADRs) were recorded on case report forms for each patient. ADRs were categorized by all body systems based on the US FDA Costart Dictionary.. The overall incidences were as follows: BodySystem

F Pts. No

%

Whole body Cardiovasc Digestive Hematologic Metabolic Musculoskel Nervous Respiratory Skin Senses UrogenitaP

191 63 695 189 30 19 225 271 98 149 137

6.8 2.2 24.6 6.7 1.1 0.7 8.0 9.6 3.5 5.3 4.9

ASA Pts_ No. % 76 28 284 58 6 3 90 105 48 156 41

12.1 4.5 45.4 9.3 1.0 0.5 14.4 16.8 7.7 24.9 6.5

IBU Pts. No 5 5 40 20 1 0 12 t0 8 7 17

% 1.8 1.8 14.1 7.0 0.4 0.0 4.2 3.5 2.8 2.5 6.0

PLA Pts. No. % 11 2 38 8 0 1 9 13 4 5 10

4.0 0.7 13.9 2.9 0.0 0.4 3.3 4.7 1.5 1.8 3.6

With the exception of metabolic and musculoskeletal systems, F induced lower incidences of ADRs than ASA. Overall, ADR incidences in the IBU and pea. groups were lower than in the F group but smaller numbers of patients in these t w o groups could have influenced the results. The incidences of specific ADRs under each of the body systems followed these group patterns. In conclusion, the incidences of ADRs reported with F appear to be similar as with the newer NSAIDs. This view is supported by literature data and marketing experience from other countries. The Upjohn Company, Kalamazoo, M149001, USA

OPC-8212 is a promising new inotropic agent. No significant toxicity was detected in clinical trials in J a p a n involving 259 patients. However, early clinical trials in the U.S. were marked by 4 cases of agranulocytosis out of 28 patients. This raised the possibility of a large ethnic difference in toxic potential of the drug. Another difference in the two populations was that 7 of the U.S. patients had received an influenza vaccination shortly prior to. or during 0PC-8212 therapy, while influenza vaccination is very uncommon in Japan. All of the US patients who developed agranulocytosis had been vaccinated, and none of 21 U.S. patients who did not receive vaccine developed agranulocytosis. We have demonstrated that several other drugs that axe associated with agranulocytosis are metabolized to reactive metabolites by activated neutrophfls or by the combination of myeloperoxidase and hydrogen peroxide. These drugs include propylthiouracil, procainamide and dapsone. We hypothesized that these reactive metabolites, formed on the surface of neutrophils or neutrophfl precursors which contain myeloperoxidase, could be responsible for drug-induced agranulocytosis. We, therefore, tested whether OPC-8212 could also be oxidized by activated neutrophils. Human neutrophils were isolated by gradient centrifugation and incubated with radiolabeled OPC-8212. The cells were activated with either phorbol ester or opsonized influenza vaccine, After incubation for 45 rain, the cells were collected on a Mfllipore filter, washed extensively with methanol and the radioactivity determined, Significant covalent binding was not detected in control cells that had not been activated, In contrast, 0.58 _+ .07 % of the 0PC-8212 became covalently bound to influenza vaccine-activated cells and 4.33 + , 17% of the OPC-8212 became covalently bound to phorbol ester- activated cells. These data axe consistent with the hypothesis that the initial step in drug-induced agranulocytosis is covalent binding of a reactive intermediate to activated neutrophils or their bone marrow precursors. In addition, these data are consistent with activation of neutrophils by some stimulus, such as influenza vaccination, representing one r i s k factor for drug-induced agranulocytosis; Faculties of Pharmacy and Medicine, University of Toronto, Toronto, Canada. M5S-2S2,

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OP 10.04

OP 10.06

SORBINIL HYPERSENSITIVITY REACTIONS ASSOCIATED WITH DIMINISHED OXIDATIVE METABOLITE DETOXIFICATION. N. H. Shear and S. P. Soielbera Sorbinil is an hydantoin aldose reductase inhibitor that has shown great promise for the treatment of diabetic neuropathy and retinopathy. Approximately 10% of patients have developed reactions characterized by fever, skin rash (exanthematous, erythema multiforme, toxic epidermal necrolysis), and myalgia. Structural similarities between sorbinil and phenytoin suggest that the pathogenesis of hypersensitivity reactions might be similar. Our previous studies of phenytoin showed that increased susceptibility to reactions results fro,~ an inherited cellular defect in detoxification of reactive oxidative metabolites. We undertook this study to determine it sorbinil is metabolized to potentially toxic intermediates, if cells from 6 patients with a history of a reaction to sorbinil are more sensitive to toxicity from such metabolites, and if susceptibility to both sorbinil and phenytein toxicity result from a similar detoxitication detect. The patient population was an average of 40 years old (25 - 64 yrs) and the indications for sorbinil therapy were either diabetic neuropathy or retinopathy. Microsomalgenerated metabolites of sorbinil (50 ~M) were toxic to normal peripheral blood lymphocytes (7.9 +0.3 % dead cells (%)). Toxicity was increased in the presence of an epoxide hydrelase inhibitor (17.5 + 0.3 %) and abolished by an inhibitor of cytochrome P450. In contrast to cells from healthy controls (7.9 + 0.7 %, N=10, age and sex-matched) and diabetics who tolerated sorbinil (7.8 + 0.4 %, N=9, age and sex-matched), toxicity from metabolites of sorbinil and phenytoin to cells of the 6 patients who had sorbinil reactions was significantly increased (19.7 +_2.3 %, P<0.0001). Cells from 3 patients who had reactions to phenytoin were similarily sensitive to sorbinil metabolites (23.4 + 0.3 %). We conclude that sorbinil is oxidatively metabolized to a potentially toxic intermediate. Certain patients may be at increased risk of developing hypersensitivity reactions due to a cellular defect in enzymes critical for the detoxification of such metabolites. Sunnybrook Medical Centre, Hospital for Sick Children, and the University of Toronto Centre far Drug Safety Research, Toronto, Ontario, M4N 3M5, Canada.

S K I N T H I N N I N G E F F E C T S OF T O P I C A L L Y A D M I N I S T E R E D CORTICOSTEROIDS M. K i e t z m a n n and D. L u b a c h B e s i d e the a n t i i n f l a m m a t o r y p o t e n c y , c o r t i c o s t e roids show different side effects. The skin t h i n n i n g e f f e c t , i n d u c e d b y an a n t i p r o l i f e r a t i v e and a t r o p h i c a c t i o n , is of c l i n i c a i i m p o r t a n c e . W h i l e the a n t i i n f l a m m a t o r y p o t e n c y of d e r m a t o c o r t i c o s t e r o i d s is t e s t e d b y the v a s o c o n s t r i c t o r assay, the p s o r i a s i s - p l a q u e - t e s t is u s e d to demonstrate antiproliferative effects. An animal m o d e l for s c r e e n i n g the a n t i p r o l i f e r a t i v e p o t e n cy of d e r m a t o c o r t i c o s t e r o i d s s e e m s to b e the h y p e r k e r a t o t i c m o u s e tail, s h o w i n g o r t h o k e r a t o tic and p a r a k e r a t o t i c r e g i o n s . S t u d i e s w e r e d o n e to c o m p a r e the s k i n t h i n n i n g p o t e n c y of d i f f e r e n t d e r m a t o c o r t i c o s t e r o i d s in h u m a n a n d m o u s e skin. The skin fold t h i c k n e s s in hunlan b e i n g s and mice, h i s t o m e t r i c d a t a and the t h y m i d i n e t r i p h o s p h a t e i n c o r p o r a t i o n r a t e in e p i d e r m a l D N A of m o u s e e p i d e r m i s w e r e m e a s u r e d a f t e r t r e a t m e n t with alelomethasone-17,21-dipropionate, betamethasone-17-valerate, clobetasole-17-propionate, d i f l o r a s o n e - 1 7 , 2 1 - d i a c e t a t e and h y d r o c o r t i s o n e 17-butyrate. All tested dermatocorticosteroids induced dermal atrophy and diminished epidermal proliferation. Only hydrocortisone and alclom e t h a s o n e - 1 7 , 2 1 - d i p r o p i o n a t e led t o m o d e r a t e e f f e c t s , w h i l e the o t h e r d e r m a t o c o r t i c o s t e r o i d s i n d u c e d a s i g n i f i c a n t s k i n t h i n n i n g . In c o n c l u s i o n it s e e m s to be p o s s i b l e to t e s t the skin t h i n n i n g p o t e n c y of d e r m a t o c o r t i c o s t e r o i d s u s i n g the m o u s e - t a i l - a s s a y . I n s t i t u t fNr P h a r m a k o l o g i e , T o x i k o l o g i e ~ n d Pharmazie, Tier~rztliehe Hochschule und Hautk l i n i k L i n d e n , B ~ n t e w e g 17, D - 3 0 0 0 H a n n o v e r

OP 10.05

OP 10.07

PLACEBO EFFECT IN HEALTHY VOLUNTEERS DURING PHASE I

PREVALENCE OF DOPING IN ZAGREB REGION (A SAMPLE OF YUGOSLAV SPORTISTS ) A. Margan-Nikoli6, B. Vrhovac, V. Plav~i6~ A. Wolf-@oporda, F. Plav~i6 Urine analysis of a sample of 110 out of 440 top sportsmen was performed. Urine was collected after the informed consent had been obtained before training. Analysis by using thin-layer chromatography (stimulants , narcotics, beta blockers) and radio irm~unoassay methods (metenolon, alpha-methyl testosterone, testosterone/epitestosterone) was performed. Doping substances have been found in 13.30/oof.samples, out of which 54.5% hormones and 45.5% members of the amphetamine group. K survey by questionnaire has been conducted among another group of 116 top sportsmen, dealing with adverse reactions and availability distribution of doping substances, role of physicians and coaches in doping, sources of information about doping, the chances of doping to help a bad competitor to become a winner and readiness of sportsmen to risk their health for results. 0nly I0.3~/o sportsmen are fully informed about various adverse reactions of doping substances. Practically all are aware (94 .8%) that there are special dealers of doping substances Acknowledged sources of information are primarily physiciar~$ (71.8~176 Coaches (120/o), fellow sportsmen (8.6%) and publications (8.60/~ have a smaller importance. A large number (30%) agreed that doping substance could (are?) be given by coaches instead of a vitamins without sportsmen's notice and agreement. On the other hand, 11.2% admitted that they would risk their health for victory and 12.9% believe they can become winners by using doping substances. The percentage of doping found in this study is surprisingly high, in spite of the fact that serious adverse reactions are well known and that its efficacy have never been proved. These results indicate the necessity of prevention: continuous and regular doping control and education of sportsmen, doctors and coaches, and promotion of antidoping by all possible ways. Prescribing of drugs to sportsmen should be more carefully performed.

STUDIES.

B. Forsythe. PH. DsnJQu, P. Rosenzwelg, Ch. Porquet, P,L. Morselll. An extensive literature exists on the "placebo effects" in clinical situations and/or clinical trials where patients receive "a treatment" (verum or placebo) and are expecting to benefit from the therapy. The issue has been less extensively discussed for phase I studies. In fact the psychological situation of the subject is quite different from that Of the patient : no benefit (except a financial reward) is expected and the attention of the subject is focused on possible adverse events. We have recently reviewed the incidence and the distribution of the adverse events reported during31 phase I studies, analyzing the data of 293 healthy young volunteers who received placebo. The studies were either single dose (SD) (n=177) or repeated dose (RD) (n=l16) administrations, where placebo was given in blind sequence with differents drugs : antiallerglc, antlanginal, antidepressant, anxlolytics, hypnotics and antihypertensives. The overall incidence of adverse events in the placebo sessions was 24.9%. More frequent events were headache (7.8%) and sedation (asthenia + drowsiness = 9.2%). The nature of the comparative drug did not appear to influence the type of adverse events reported during the placebo sequences. The type of adverse events and their incidence appeared to be different in SD and RD studies. Headache and drowsiness were in fact more frequent in SD studies and asthenia and fatigue were mostly present in RD studies. On the whole, the data suggest a rather high incidence of adverse events during placebo sessions in healthy volunteers. The possible influence of the experimental design and of the experimental environment will be discussed. Synthelabo Recherche (LERS) Dept of Clinical Research 58 rue de is Glaci~re 75013 PARIS FRANCE.

Section of Clin.Pharmacol., Dept. of Medicine, University Hospital Rebro, Zagreb, Yugoslavia

A 55

OP 10.08

OP 11.02

FLUNARIZINE AND NIMODIPINE BUT NOT KETANSERIN AND RITANSERIN ARE ANTIDOTE TO LETHAL IMIPRAMINE INTOXICATION IN RATS M. 8it~n. R. Trouv& C. Late~r ~,nd G. Nahas. Imipramine is widely used as an antidepressant and is responsible for many patients entering antipoison centers in Europe, primarily because o! abuse or autolysis. The fatality rate is approximatively 2% and 80% of the survivors have neurologic damages. For the past 30 years no specific treatment was available, and the management of intoxicated patients was purely symptomatic. Imipramine is believed to inhibit the reuptake of serotonin and noradrenaline, and serious intoxication is associated with a grave parasympathetic syndrome. In a former study on rats, we demonstrated that Flunarizine, Nicardipine and Nimodipine, three calcium channet b~ockers with cerebrovascular effects, were good antidotes to imipramine lethal intoxication. However, specific serotonin receptors antagonist such as Ritanserin, or mixed serotonin- alpha adrenergic antagonist such as Ketanserin are readily available and are being considered without proof to be a more specific treatment of imipramine intoxication.The latter were evaluated in two groups of 6 rats fitted with a caudal catheter and connected to a computerized cardiovascular monitoring system. They received a lethal dosage of 85 mg/kg of imipramine IP and were treated 5' after intoxication with a mean dose of 800 u_g/kg of Ketanserin or 550 p.g/kg of Ritanserin. Although arterial pressure and heart rate did not drop as severely as in 6 control rats, 3 rats treated with Ketanserin died over a period of 35' _+48, a lime not different lrom control and 3 survived. The drop of arterial pressure was more limited with Ritanserin and heart rate did not change. However, 3 rats died over 36' -+ 38 (not significant compared to control) and 3 survived. This study demonstrates that imipramine intoxication as most intoxications involving neur0modulator disturbances, is not easily controllable with so called specific treatments. This kind of intoxication is muitifactoriat and the clear advantage of the use of calcium channel blockers is the wide limitation of neuromodulators release, the limitation of neuromodulators effects by partially impairing their calcium component (if any) and the tissular protection through prevention of calcium entrance and overload in affected tissues. Flunarizine and Nimodipine prevented convulsions and coma, and the animals behaved normally following treatment. The neurological protection offered bY these drugs may be an overwhelming advantage compared to other treatments. In conclusion, at this time only Flunarizine and Nimodipine are suitable antidotes to imipramine lethal toxicity in the rat. Laboratoire de Pharmacologie et Tox;coiogie, INSERM, Paris, France and Deparlment ot Anesthesiology, Columbia University, New York, USA.

PHARMACOKINETICS OF CYCLOSPOHIN IN POTENTIAL LUNG AND HEART TRANSPLANT RECIPIENTS D.N. Batsman, A.J.B. Kirk and J.H. Dark Cyclosporin A is widely used to prevent organ rejection following transplantation. Post-operative dose requirements in graft recipients may vary due to differences in both clearance and bioavailability of cyclosporin. To delineate these factors we have investigated the pharmaeokinetics of eyclosporin pre-operatively in eight patients awaiting cardiac (6) or pulmonary (2) transplantation (seven male, aged 37-54 years). Cyclosporin was given twice as a single dose (4mg/kg) and by I.V. infusion (Img/kg) over six hours in random order on consecutive days, and blood samples collected at appropriate intervals for 24 hours. Whole blood eyelosporin was measured by monoclonal RIA (Sandimmun). Total body clearance (DOSE/AUC) after I.V. dosing varied more than twofold (range 6.5-14.1 l/h, mean 10.6 + SEN 1.021/h). Apparent VD was 2.5 j 0.28 i/kg (range 1.7-4 I/kg) and terminal half-life was 11.2 J 0.54 h. Oral dose-corrected bioavailability was 31 + 2.1% (range 21-40Z) and terminal half-life after oral administration was similar to I.V (10.2 ~ 0.88 h). I.V. clearance correlated significantly (r = 0.815 p < 0.01) with ereatinine clearance but net bioavailability. The concentration-time profiles of whole blood concentrations of cyelosperin were similar with these two different doses and modes of administration, suggesting I.V. infusion over six hours as an alternative dosing method in transplant recipients. Welfson Unit of Clinical Pharmacology, The University and Cardio Pulmonary Transplant Unit, Freeman Hospital, Newcastle upon Tyne.

OP 11.01

OP 11.03

NIFEDIPINE DOSE OPTIMIZATION IN HYPERTENSIVE PATIENTS N. Bacracheva I, P. Thuermann 2 and N. Riethrock 2

P}~RMACOKINETICS AND INFLUENCE ON HEMOSTATIC PARAMETERS OF TISSUE PLASMINOGEN ACTIVATOR AFTER INFUSION IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION E. Seifried, W. H~rer, D. Ellbr~ck, P. Tanswell,A. Schmidt Plasma levels and systemic effects of recombinant tissue type plasminogen activator (rt-PA) were determined during coronary thrombolysis in 12 acute myocardial infarction patients using a consecutive intravenous infusion regimen. i0 m g r t - P A were infused in 2 minutes resulting in a peak plasma concentration (mean + SD) of 3310+ 950 ng/ml, followed by 50 mg in 1 h and 30 mg in 1.5 h yielding steady state plasma levels of 2210 J 470 ng/ml and 930 + 200 ng/ml respectively. All patients received intraveno]s heparin. Total clearance of rt-PA was 380 + 74 ml/min, tl/2alpha was 3.6 ~ 0.9 min and tl/2B was ~6 ~ 5.4 min. After go min, in plasma samples containing anti-rt-PAIgG to inhibit in vitro effects, fibrinogen was decreased to 54%, plasminogen to 52%, alpha-2-antiplasmin to 25%, alpha-2-maeroglobulin to 90% and antithrombin III to 85% of initial values. Coagulation times were prolonged and fibrin D-dimer concentrations increased from 0.40 to 2.7 ~g/ml. It is concluded that pharmacokinetics of rt-PA show low interpatient variability and that its short mean residence time in plasma allows precise control of therapy. Apart from its moderate effect on the hemostatic system, rt-PA appears to lyse a fibrin pool in addition to the coronary thrombus. Medizinische Klinik der Universit~t Ulm, Abteilung Innere Medizin III, Robert-Koch-Strasse 8, D-7900 Ulm

Ten patients with essential hypertension

(WHO grade I-II),

aged 40-62 ys., were treated in an open dose-optimization study with slow-release nifedipine (N) given as standard therapy (20 mg bid) for 2 weeks and as an individualized dose for 6 weeks. The optimum dose, defined as that producing a diastolic blood pressure was determined relationship

from the individual

(dBP) of 90 mm Hg,

concentration-effect

after a test-dose of 20 mg. Heart rate,

BP at

rest and N plasma concentrations were measured at 2-week intervals before and 2h after drug intake. Under standard therapy, the reduction in dBP was insufficient in 4 and more than that required in 2 patients. After 2-week individualized treatment, the required antihypertensive effect was obtained in all patients. The mean pretreatment dBP was reduced from i07h7 mm Hg to 87~9 mm Hg under standard treatment

therapy

(p<0.05)

and to 8it9 mm Hg (p<0.05)

with optimized dose measured 2h post-dose.

on The

optimized doses needed were l0 mg bid, i0 mg tid, 20 mg bid, 20 mg tid and 20 mg qid. One patient dropped out of the study because of side effects. A loss of antihypertensive

effect was observed

weeks of treatment,

in 1 patient

on the optimized dose,

after 6

the average of

the pre- and 2h post-dos e N concentrations at steady state (26.8+9.6 ug/l) compared well with model-derived optimum

concentrations (28.6i13 ug/l). These results show that antihypertensive therapy with nifedipine can be optimized in the individual patient using a derived dose from concentration-effect analysis. l)Chair of Clin. Pharmacol., Inst. Pharmacol. Pharm., Medical Academy, 1040 Sofia, Bulgaria; 2) Dpt. of Clin. Pharmakol., J.W. Goethe-University, Frankfurt/Main, FRG.

A 56

OP 11.04

OP 11.06

FAMOTIDINE: PHARMACOKINETIC PROPERTIES AND SUPPRESSION OF ACID SECRETION IN PAEDIATRIC PATIENTS UNDERGOING CARDIAC SURGERY D.R. Krlshna, G. Kraua, D. Chmelarach, M. Schmld and U. Klotz

STEADY-STATE TACRINE PHARMACOKINETICS IN PATIENTS WITH ALZHEIMER'S D I S E A S E (AD) N . R . C u t l e r , P . L . P r i o r , B. U n d e r w o o d , A . J . S e d m a n , A. S e ! e n , L. B a l o ~ h , P. W e l ! i n ~ , A. K i n k e i S t u d i e s on n e u r o c h e m i s t r y and neuropachology in AD s u g g e s t d e f i c i e n c i e s in the c h o l i n e r g i c s y s t e m in AD. Therefore, t a c r i n e , an o r a l cholinesterase inhibitor, is b e i n g s t u d i e d for the t r e a t m e n t of AD. We h a v e e v a l u a t e d the steady-state pharmacokinetics of t a c r i n e in 9 f e m a l e s ( m e a n a g e = 77 y e a r s ) w i t h A D . Each patient sequentially r e c e i v e d n i n e d o s e s of 10, 20, a n d 30 mg o f l a t r i n e e v e r y six h o u r s . Blood samples were collected for up to 24 h o u r s a f t e r the l a s t d o s e . Plasma tacrine concentrations were measured using a specific, validated HPLC method. Mean maximum plasma concentrations (Cmax) were 5.11, 20.7, and 33.9 ng/ml, respectively. Corresponding values for area u n d e r the c u r v e (AUC) w e r e 19.8, 8 3 . 7 , a n d 141 n g o h r / m l . Dose normalized Cmax and AUC, determined following administration of 20 a n d 30 mg d o s e s of l a t r i n e , w e r e s i g n i f i c a n t l y greater (p<0.05) t h a n t h o s e a f t e r lO m g . The average drug elimination half-life was approximately 3 . 4 h r s . at all d o s e l e v e l s . Dose dependent increases in C m a x a n d A U C observed in p a t i e n t s w i t h AD w e r e s i m i l a r ~o those reported previously in n o r m a l v o l u n t e e r s . Saturable first-pass hepatic metabolism m a y be responsible for dose-dependent tacrine kinetics.

The pharmacoklneUc and phsrmacodynamic properties of the new H2-receptor antagonist famotidine have been well described in adult subjects. However, similar data are missing for children. In our clinical study 10 paediatric patients with normal kidney function (age range 2-7 years, body weight 14-25 kg) received as prophylactic medication to prevent aspiration toltowing cardiac surgery and prior to extubation after prolonged ventilation a single Intravenous dose of 0.3 mg/kg of famotidine. Plasma concentrations of famotidine and gastric pH-values were both monitored for at least 12 hours by HPLC and aspiration of gastric juice respectively. Plasma levels of femotidlne (initially 225 to 812 ng/ml; after 12 h 11 to 35 ng/ml) declined with an elimination half-life of 3.3 -+ 1.8 h (mean ~- SD) and it was effective in elevating the gastric pH above 4 for about 10 hours. The variable distribution volume and total plasma clearance (CL) of famotidine averaged 1.4 _ 1.0 I/kg and 5.1 r 2.9 ml/min/kg respectively. In 4 patients unchanged famotidine could be measured additionally in a 12 hour urine fraction. The excreted amount (21 - 79 % of dose) correlated with CL (r = 0.97). All these data are comparable to those obtained in healthy adults indicating that paedistric patients receiving intensive medical treatment after cardiac surgery can handle a low intravenous dose of famotidine in a very similar way to normal subjects.

California Clinical Trials, 8500 Wi!~hire Beverly Hills, California 90211 U.S.A.

Supported by the Robert Bosch Foundation, Stuttgart. Dr. Margarete Fischer-Bosch-lnstitut fDr Klinische Pharmakologie, Auerbachstr. 112, D-7000 Stuttgart 50 / FRG.

Parke-Davis Pharmaceutical Warner-Lambert

Research Company,

Division Ann Arbor,

Michigan

Blvd.

U.S.A.

OP 11.05

OP 11.06

PHARMACOKINETICS OF OMEPRAZOLE IN PATIENTS WITH LIVER DISEA

STEADY-STATE TACRINE PHARMACOKINETICS IN PATIENTS WITH ALZHEIMER'S D I S E A S E (AD) N.R. C u t l e r , P . L . P r i o r , B. Under~;ood, A . J . S e d m a n , A. S e ! e n , L. B a ! o ~ h , P. W e l ! i n ~ , A. K i n k e l S t u d i e s on n e u r o c h e m i s t r y and n e u r o p a t h o l o g y in AD s u g g e s t d e f i c i e n c i e s in the e h o l i n e r g i c s y s t e m in AD. Therefore, t a c r i n e , an o r a l choiinesterase inhibitor, is b e i n g s t u d i e d for the t r e a t m e n t of AD. We h a v e e v a l u a t e d the steady-state pharmacoktnetics of t a c r i n e in 9 f e m a l e s ( m e a n age = 77 y e a r s ) w i t h AD. Each patient sequentially r e c e i v e d n i n e d o s e s of i0, 20, and 30 mg a f l a t r i n e e v e r y six h o u r s . B l o o d s a m p l e s w e r e c o l l e c t e d for up to 24 h o u r s a f t e r the l a s t d o s e . Plasma tacrine concentrations were measured using a specific, validated HPLC method. Mean maximum plasma concentrations (Cmax) were 5.11, 20.7, and 33.9 ng/ml, respectively. Corresponding values for area u n d e r the c u r v e (AUC) w e r e 19.8, 8 3 . 7 , a n d 141 n g - h r / m l . Dose normalized Cmax and AUC, determined following administration of 20 and 30 mg d o s e s of l a t r i n e , w e r e s i g n i f i c a n t l y greater (p<0.05) t h a n t h o s e a f t e r I0 m g . The average drug elimination half-life was approximately 3 . 4 hrs. at all d o s e l e v e l s . Dose dependent increases in C m a x a n d A U C o b s e r v e d in p a t i e n t s w i t h AD w e r e s i m i l a r Co those reported previously in n o r m a l v o l u n t e e r s . Saturable first-pass hepatic metabolism m a y he regponsible for dose-dependent tacrine kinetics.

SE.

R.RONDANELLI,N.REGAZZI,R.CERUTTI,M.CISTERNINO,R.SIVELLI,M. RINETTI Omeprazole,a :H+/K+ AT base inhibitor,is a potent suppressor of gastric acid secretion and a very active substance in the treatment of duodenal and peptic ulcers.The kinetic pr~ file of Omeprazole is well defined for healthy volunteers and for some hight-risk population but not so far for patients with liver disease. As the substance is mainly meta bolized in liver,changes in liver circulation and/or func~ tione might lead to change the drug pharmaeokinetics. Aim of the study was to evaluate the kinetic profile in pa tients with liver disease and compare the results obtained in healthy volunteers. ~ETHODS 16 subjects were included in the study:8 patients with liver cirrhosis (I) and 8 healthy volunteers (II).A single oral dose of Omeprazole 20 mg was administered:plasma and urine samples were collected for 24 h since Omeprazole administration. The principal pharmacokinetic parameters were estimated for the two studied population. RESULTS PTS CpMAX TMAX AUC t~B C1/F (mg/l) (h) (mg.h/l) (h) (l/h)

(I) CIRRHOTIC

0.74 (0.22)

2.15 (0.78)

4.11 (1.86)

2.85 (1.68)

5.85 (2.58)

(II)

0.18

1.85

0.49

0.73

48.2

VOLUNTEERS

(0.09)

(1.85)

(0.23)

(0.04)

(13.4)

CONCLUSION On this basis we can conclude theat there is a significant increase in t~B (about 4 times) and in CI (8 times). A posible reduction in VB might explain a low increment of t~8 than in CI. Dpt. diFarmacologia PoliclinicoS.Matteo , 2710OPAVIAITALY

California Clinical Trials, 8500 Wi!~hire Beverly Hills, California 90211 U.S.A. Parke-Davis Pharmaceutical Warner-Lambert

Research Company,

Division Ann Arbor,

Michigan

Blvd.

U.S,A.

A 57

OP 11.07 M.J. D'Souza, D.A. Deqree, J.R. Eckman, and P.J. DeSouza Sickle cell anemia (SCA) is an inherited blood disease which can cause bouts of pain, damage to vital organs, and for some, death in childhood or early adulthood. Clinical evidence of hepatic dysfunction with SCA patients is well recognized, but no studies have been carried out to characterize drug disposition in this patient population. Such studies are partictLlerly appropriate in SCA because these patients frequently receive a number of drugs for pain control which are extensively metabolized in the liver by enzymatic oxidation and conjugation. Acetami~ophen (AC) was used as the model ~ u n d to study drug conjugation since it is completely metabolized by conjugation with glucuronic acid and sulfuric acid. Antipyrine (AP), on the other hand was used as the model compound to evaluate the functional activity of the oxidative enzymes since this drug is primarily metabolized by oxidation. After an overnight fast, each patient and normal volunteers received either one AC caplet (500rag) or one AP capsule (500r~) orally with 200 mls of water, in a crossover study design, with a 15 day washout period between subsequent studies. Blood sallples were obtained and plasma was analyzed for A P and AC levels by HPLC methods. The clearance of AP [CL:SCA = 1.14ml/min/kg; normals = 0.7ml/min/kg] and AC [CL:SC~ = 5.11nl/mi~/kg; nonnals = 2.7ml/min/kg] in the SCA patients v~as significantly higher (p<0.05) than the normals. There was a corresponding decrease (13<0.05) in the half-life of AP and AC in the SCA patients when ~ e d to controls. However, there were no significant differences in the volume of distribution between the two groups. We conclude that the increased clearances of AP and AC could possibly be due to increased activities of hepatocellular enzymes and elevated serum enzyme activities of the type considered to reflect hepatocellular damage. Meroer University Souf_he_rn School of Pharmacy, 345 Boulev-clrd, NE, Atlanta, G A 30312 and Emory University S c h o o l of Medicine

OP 12.01 PREVALENCE OF DRUG ABUSE AND -DEPENDENCE IN PSYCHIATRIC INPATIENTS ASSESSED BY A GERMAN DRUG-SURVEILLANCE PROJECT (AMOP-STUDY) SCflMIDT LG, GROHMANN R, OTTO M, PLATZ WE, WOLF B, MOLLER-OERLINGHAUSEN B M o n i t o r i n g of drug abuse and -dependence is part of a m u l t i c e n t r e s u r v e i l l a n c e p r o j e c t run in p s y c h i a t r i c h o s p i t a l s in West-Germany since 1980. W H O - c r i t e r i a for abuse and D S M - l l l - c r i t e r i a f o r dependence had been a p p l i e d f o r this study a s s e s s i n g the frequency in 15,296 inpat i e n t s of 2 p s y c h i a t r i c university hospitals and 349 in an a d i c t i o n u n i t of a s t a t e h o s p i t a l . In p a t i e n t s attending university hospitals, abuse/dependence of BZD were most f r e q u e n t l y recorded (3.4%) f o l l o w e d by non-narcotic analgesics (1.4%) and b a r b i t u r a t e s (0.7%). A n x i e t y n e u r o t i c s turned out to be h i g h - r i s k patients for p r i m a r y BZD-dependence (11.8% of this diagnostic group) followed by 3.7% of n e u r o t i c d e p r e s s i v e s (3.7%) and 2.7% o f endogenous d e p r e s s i v e s . Higher age and being f e male was a l s o r e l a t e d to p r i m a r y BZD-dependence. Non-narcotic a n a l g e s i c s were abused most f r e q u e n t l y by hypochondriacs (7.4%), who had taken n e a r l y exclusively these drugs in f i x e d c o m b i n a t i o n s . In a l c o h o l i c s and o p i a t e addicts of the s t a t e hospital, BZD had been taken by 25.5 r e s p . 31.3%, b a r b i t u r a t e s by 5.7 resp. 41.8% before admission i n d i c a t i n g high prevalence of m u l t i p l e drug abuse in these pat i e n t s . Further r e s u l t s are presented in detail. Psychiatrische Klinik und P o l i k l i n ~ k der FU B e r l i n , Eschenallee 3, D - 1000 B e r l i n 19 Supported by the Federal Health O f f i c e , B e r l i n (West)

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INTRAVENOUS 4-AMINO-I-HYDROXYBUTYLIDENE-I,I-BISPHOSPHONATE IN THE TREATMENT OF PAGET'S DISEASE OF BONE. M. Mian*, F. Begh4 ~ S. Rosini ~ and S. Adami. The treatment of Paget's disease (P's d) has been dramatically improved during the past decade. Some patients (pts) become nevertheless resistant to caicitonin (CT) and high doses of etidronate, unfortunately, induce a mineralization defect. More recently many Authors have used dichloromethylidene (CI M) bisphosphonate iBP), having the advan2 tage that it does not induce osteomalacia. Cl MBP is very 2 efficacious; moreover it can induce further biochemical response after plateau phenomenon to CT has been reached. Here we report some observations on 14 pts with active P's d of bone who were treated with 4-Amino-l-hydroxybutilidene-l,l-BP (AHButBP), given at doses ranging from 2,5 to 25 mg/day for 4 days as intravenous infusion. 5 pts had been treated with CI MBP 32 months earlier. The short course of AHButBP induced a suppression of serum alkaline phospnatase ~sAikP) and urinary hynroxyproline (uHP) values down to 30% of intial values. The biochemical suppression of the disease was sustained for 2~18 months. Time to relapse did correlate to logarithm of the dose (p<0.001). In the 5 pts previously treated for P*s d sAlkP and uHP fell to or even below the nadir values achieved with C1 MBP. The lowest values of sAlkP and uHP achievable after2treatment with BP seems to be c o n s t a n t for each pt; this might represent an unsuppresible component of disease activity such that normal levels of sAIkP and uHP cannot be attained in pts with extremely active P's d. *Institute of Pharmacology, University of Pisa, ITALY ~ Gentili S.p.A.; Pisa, ITALY Department of Nefrology, University of Verona, ITALY.

ASSESSMENT OF THE ABUSE POTENTIAL OF TRAMADOL D.R. Preston and D.R. Jasinski

Tramadol is an analgesic one tenth as potent as morphine on a mg for mg basis. To assess its abuse potential, tramado175, 150 and 300 rag, morphine 15 and 30 rag, and placebo were given intramuscularly to 12 volunteer non-dependent opiate abusers. Treatments were tested under double blind conditions on consecutive days according to two 6 x 6 latin squares. Subjective, behavioral and miodc changes were assessed prior to dosing and at 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 9, and 12 hours after drug administration. Subjective effects were measured with ARCI subscales and a series of visual analog scale measures including drug effects, liking, drug identification, and symptoms. Behavioral effects were recorded by observers who rated subjects for drug effect, liking, and signs on a series of visual analog scales. Pupil diameter was determined from photographs taken at ambient room lighting. The onset, time to peak and duration of psychoactivity for morphine and tramadol were similar. Morphine produced typical effects including miosis and increases in ratings of drag effect, drug liking, MBG (euphoria) scale scores, and identifications as an opiate. Tramadol was also identified as an opiate and produced morphine-like subjective and behavioral effects, though no miosis was detected. However, the magnitude of the effects produced by tramadol was less than that predicted by its analgesic potency relative to morphine. Tramadol 3190 mg produced effects equivalent to morphine 15 mg, and the effects of tramado175 and 150 mg were not different from placebo. There was no evidence that tramadol produced dysphoric effects as have been shown for agonist/antagonist opioids such as nalorphine, cyclazocine and pentazocine. We conclude that parenteraI analgesic preparations of tramadol have significantly less capacity to produce euphoria, subjective effects and miosis than would be expected on the basis of analgesic potency estimates. This suggests that available parenteral preparations of tramMol have a lower abuse potential than corresponding preparations of morphine. Francis Scott Key Medical Center, Johns Hopkins School of Medicine, D-5-West, 4940 Eastern Avenue, Baltimore, MD 21224, U.S.A.

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TRANSDERMALNICOTINE; PHARMACOKINETICS AND USE IN ANTI-SMOKING STRATEGIES J.G. Kelly, J.G. Masterson, S. Mulligan and J.G. Devane

DOES PHYSICAL DEPENDENCE ENHANCE DRUGSEEKING? T. Yanagita and Y. Wakasa It is well-known that once physical dependence on heroin or morphine is developed in drug users, their drug-seeking becomes compulsive in order to escape from the withdrawal discomfort. However, it is not clear whether or to what extent such enhancement exists with milder opiates such as codeine, other opioids such as pentazocine, and drugs with little if any physical dependence potential such as cocaine and nicotine. To answer this question, animal experiments were conducted in intravenous self-administration of these drugs in rhesus monkeys under progressive ratio procedures for assessing the intensity of drug-seeking behavior under both the physically dependent and physical dependence-free states. In the experiments monkeys were obliged to press a lever an increasing number of times in order to receive each succeeding dose, and the lever-press ratio at the last obtained dose was regarded as indicating the intensity of the drug-seeking behavior. As a result, a marked enhancement of the drug-seeking behavior for morphine or dihydrocodeine was observed when physical dependence was developed on these drugs. The final ratios obtained under the physically dependent state were 4.0 times higher with morphine 0.25mg/kg/injection and 6.2 times higher with dihydrocodeine 1.0mg/kg/in] in average of 4 monkeys than those obtained under the physical dependence-free state. The enhancement was less marked with pentazocine (with the average final ratio 1.7 times higher at 1.0mg/kg/inj) and nil with cocaine or nicotine. Thus, the extent of the enhancement was roughly proportional to the severity of the gross behavioral withdrawal manifestation for each drug observed in rhesus monkeys. Preclinical Research Laboratories, Central Institute for experimental Animals, Nogawa, Kawasaki 213, Japan

The association of nicotine with physical dependence upon cigarette smoking has led to strategies designed to replace tobacco-derived nicotine with nicotine from other sources. Administration of nicotine orally, transdermally in solution and orally as chewing g u m has been reported to reduce cigarette craving and nicotine chewing gums have been widely used for some years. We have investigated the use of a sustained-release transdermal forrcLulation of nicotine applied as a daily patch containing 30 mg. In a pharmacokinetic study in 9 volunteer subjects, a single patch was applied daily for 7 days. Values for days 1 and 7 respectively (mean + sem) were : Onax, ng/ml, 15.99 ~ 5.00 and 16.97 J 5 . 1 3 ; Tmax, h, 7.78 + 2.54 and 6.00 + 2.00; 24h conc., ng/ml, 4.58 + 2.50 and 4,81 + ].74. In an efficacy study, 80 volunteer smokers participated in a double-blind, quit-rate study. Patches were applied daily for a maximum of six weeks. At 6 weeks, 50% of those in the nicotine group claimed to have quit smoking against 17.5% receiving placebo. Based upon blood carbon monoxide levels, these figures were 47.5% and ]2.5% respectively (P=0.001, Chi-Square). Ten subjects in each group reported skin irritation. 2 in the placebo and 7 in the active group had a localised transient rash, 3 in the placebo and 4 in the active group had transient erythema. We conclude that this transdermal nicotine preparation shows sustained absorption characteristics and is suitable for evaluation in smoking-cessation strateqies. Elan Corporation plc, Monksland, Athlone,

Ireland.

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A MULTICENrRIC STUDY TO INTRfITJCE NALTREXONE I~ SPAIN ORGANIZED BY T ~ REGULATORY ALTIFORITY. F. Garcla-Alonso, R. Palop and the Spanish Study Group in D r ~ Addiction. Ministry of Health. Paseo del Prado 18-20, Madrid. Spain. The objeotive was to determine if Naltrexcne (a long acting oral opiate antagonist) would be of any value for opiate addiction in Spain since most of the published studies were cerried out in the United States. The study was organized by the spanish Regulatory Authority in order to establish regulatic~s that should apply to the use of Naltrexone. Methods Two types of patients, ncn-selected in terms of social class or professional skill, were recruited : i13 opiate dependents with a history of more than 18 months and less than 4 years regular opiate use who were not currently usdergoing treatment with Methadone. 37 sporadic consumers of opiates, without addiction, with a history of use of no more than 18 months. In a inpatient regimen, patient~ of the first group were detoxified with clonidine over a period of 7 days. At the end of this period, a Naloxone challenge test was used to verify the lack of heroin withdrawall. Afterwards if this test was negative, in both groups, the treatment with Naltrexone (Mondsy and Wechesday, i00 rag., and Friday 150 rag.) was begun. This treatment continued ustil 6 months had elapsed frcm this moment. Psyshoterapeutic treatment was given simultaneously. The fumdemental criterion to evaluate efficacy wasthe retention rate. Results Forty percent of the subjects in both groups remained in the study for at least 6 months frc~ onset of Naltrexone treatment. This is superior to any previously reported for ~%sellected groups of drug addicts and abusers. Conclusion The good clinical results obtained in this study are probably not exclusively due to Naltrexone. The methodogical limitations of this study does not allow a clear distinction between the irIluenee of Naltrexone, psychotherapy and other non-pharmacological factors. In any case, the drug was laumched in Spain (January 1989) without restrictions and with the recomendation of cenccmitant use of psychotherapy.

NOVEL MEDICINES t~ARKETEDIN THE UK AND INTERNATIONALLY(1960-1988) S. R. Walker and Y. Li~ In the last 30 years there has been a significant increase in the number of medicine available worldwide, with 1895 New Chemical Entities (NCEs) introduced between 1961 and 1987. Six hundred and seventy nine have reached the UK market, the majority of which have been orignated (88%) and marketed (95%) by American, British, French. West German, Swiss and Swedish companies. However the number of NEEs introduced annually to the UK declined in 1964 from an average of 50 per year to 21, remaining f a i r l y constant until the early ig80s. In 1984 i% decreased further, with only 24 introductions in the next three years. Since 1960 average development times (patent f i l i n g be marketing in the UK) steadily increased, quadrupling to a peak of 13 years for those NCEs reaching the market in 1984 and resulting In a concomittant decline in effective patent life to only 5 years for the cohort marketed in 1986. Residence time in the clinical development phase (let into man to PL application) reached an average of nearly 8 years in the early lg8Os, with regulatory delay increasing at the product licence stage and contributing significantly to overall development time. The interval between PL approval and marketing varying between 2.5 and 6 menths throughout the period of study. Th~ majority of comnoundsmarketed were central nervous system (CNS] compounds (27%), anti-infectives (18%), and cardiovascular system agents (16%), representing 416 of the total numberof NCEs introduced. Mean development time for CNS compoundswas consistently higher than that of the whole cohort, with the differential between the three major therapeutic categories increasing, so that in the 1980s it averaged 13 years for CNS compounds, and was 54% and 28% longer than for antiinfective and cardiovascular compoundsrespectively. This study demonstrates a numberof adverse trends in the innovative process since the early 1960s, with a decrease in the rate of new introductions, significantly increased developmant time and reduced effective patent life. Data from the cohort marketed in the UK since 1980 (137 NCEs) is examined in an international context, with an examination of trends in international development time, effective patent life, regulatory delay, drug lag and the extent of dissemination of the NCEs onto other major markets. Centre for Medicines Research, WoodmansterneRoad, Carshaiton, Surrey, SM5 4DS, England.

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AUTOMATED INTERPRETATION OF THE MAC KENZIE TEST C. Piette, M. Herbin, A. Venot, M. Letrait, O. Reigneau, D. De Lauture, F. B o ~ a r t , A. Opriou, J.Y. Devaux, A. Giard and G. Strauch. Mac Kenzie test is frequently carried out in healthy volunteers in order to compare topical cortieosteroids (TC) pharmaeodynamics. These drugs are responsible for skin blanching which is evaluated using subjective scales. During the double blind study of a new drug, we have compared the performances of visual assessments with automated ones derived from the processing of true color slides of the volunteers.

CONTROLLEDRELEASE

DRUG

DELIVERY SYSTEMS FOR

ANTIMALARIAL AGENTS

S. K. Das, S. C. Chattara] and B. K. Gupta In view of the present situation of rapid emergence of resistance strains of the malaria parasite towards the antimalarial agents in coventional dosage forms, the overall objective of the study was to develop therapeutically viable drug delivery systems of the antimalarial agents capable

216 blanching patches were obtained from placebo, class 1 and 2 TC applied on 12 volunteers observed and photographied at two times after the drug application. We assumed that placebo blanching was inferior to class 2 blanching itself being inferior to class 1 blanching. These assumptions were used to compare the different indexes on the basis of the percentage of such inequalities which were correctly recovered. Different color models were studied (mainly the r,g,b chromatic and Luminance, Hue, Saturation systems). The drug responses were measured in terms of color differences between the normal and exposed skins. Differences in red chromatic, green chromatic, saturation and hue and the average results permitted to respectively recover 93, 94, 88, 91 and 82 % of the postulated inequalities. These results indicate that image processing can provide better results than visual assessments. Blanching can be quantitated in terms of chromatic red or green, or hue variations. This automated interpretation is simple and can be proposed for a general use.

of delivering the drug at a preprogrammed rate thus reducing the chances of development of resistant strains of parasite towards the drug, at the same time minimizing the side effects and maximizing the therapeutic benelit~ through controlled release techniques. Controlled release mu]tiunit dosage forms

of

sulfadiazine,

primaquine

with

dihydro-

folate reductase inhibitor were formulated using methacrylate ester copolymers. Physicochemical and in vitro drug release profile were investigated. Comparative bioavailability studies were conducted in human volunteers. Significant increase of dissolution half life of the products were observed. This study has illustrated the development of most rational drug delivery system for chemotherapy Of malaria. Department of Pharmacy, Jadavpur University,

IRT-ECLIMED, H~pital Cochin, 75674 Laboratoires Unicet, Paris, FRANCE.

Paris eedex 14 and

Calcutta 700 032, India.

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DRUG DEVELOPMENTAND THE ELDERLY W. B. Abrams I t is now generally appreciated the world is aging and older persons disproportionately use drugs and experience a d v e r s e effects. Altered drug disposition and pharmacodynamic responses, drug and disease interactions, and lack of guidance to physicians contribute to the problem. The drug development community has responded by altering clinical r e s e a r c h practices to systematically include older individuals in investigational new drug programs. Pending FDA Guidelines call for early pharmacokinetic studies, investigation of possible age-related differences in end-organ responses, conducting appropriate drug interaction studies, and including the elderly in Phase I I and I I I studies and assessing the results for age-associated effects on efficacy and safety. The essential purpose is to provide information relative to dosage or precautions to be followed when treating old patients. Recent new drug programs will be discussed relative to t h e u t i l i t y of these guidelines in developing c l i n i c a l l y relevant information. Merck Sharp & Dohme Research Laboratories, West Point, PA 19486, USA

FOLK-DICHOTOMY HYPOTHESIS: THERAPEUTICS.

CONSEQUENCES FOR PHARMACO-

N. Z. Nyazema, D. T. Chavunduka and E. Jasset. The folk dichotomy or aetiology hypothesis states that the use of modern as against indigenous sources of therapy can be explained by determining whether the disorder is believed to be of natural or supernatural origin. The rationale behind this dichotomy is that some people in Zimbabwe generally feel that the modern medicine is incomplete, amoral and descriptive, as it has no li~
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DROMED 12: A SOFTWARE WHICH PROCESSES PHASE 1 DATA FOR OPTIMIZING DOSAGE REGIMEN OF PHASE 2 TRIALS

ACETYLATOR STATUS IN KWASHIORKOR DISEASE L. H. Jeyakum~r and E. A. Bababunmi

H. Piet-Lahanier, A. Venot and G. Strauch During phase i, limited individual pharmacokinetic (PK) data are obtained on numerous healthy volunteers. These contain valuable "information on the drug PK interindividual variability. This work presents DROMED 12, a software that pools and processes these data together in order to determine an optimal dosage regimen for phase 2 trials. Single dosing assay results or first administration of repeated doses, satisfying the assumption off linearity of drug response versus dose, are selected. These data are used to predict the PK behaviour of every subject for any dosage regimen (repeated dosings). Several dosage regimen optimality criteria are proposed, depending on the type of drug studied. These criteria are designed to quantify the quality of a regimen with regards to the behaviour of the whole treated population. Such a criterion may be the percentage of subjects whose drug plasmatic concentrations lay under a maximal value no more than x hours and over a minimal value more than y hours. A global optimizer, based on random search technique, determines the dosage regimen (a sequence of administration times and dose values) which optimizes the selected criterion. This dosage regimen is not optimal for an average patient but for the whole treated population. DR0~ED 12 has been tested on simulated and real data. It is running on Vax and Microvax series under VMS. This software constitutes a practical tool which can be used before the final design of phase 2 studies, in order to increase the drug efficiency and limit its toxicological risks. Its main limitation consists in the assumption of PK linearity. The extension to non-linear PK as well as to Pharmacodynamic data is currently studied. IRT-ECLIMED, H6pital Cochin, 75674 Paris eedex 14 and LSS, CNRS-ESE, 91192, Oil sur Yvette cedex, FRANCE.

The incidence of protein energy malnutrition (P~IM) is quite high in Africa. Among children PEM may be encountered as Kwashiorkor, Marasmus or l~rasmis-Kwashiorkor. In general this human disease is a nutritional disorder. Several host factors and diet as well as the environment play a role in the pathogenesis and expression of the disease. Information is scanty on the factor of malnutrition on gene expression in human populations in tropical Africa. Indeed certain hepatic enzymes such as cytochrome oxidase and N-acetyl transfsrase can serve as unique proteins for biochemical and genetic studies in health and in certain nutritional diseases (R.A. Shastri and K. Krishnaswamy, Brit. J. Clin. Pharmacol. 7, 69-73, 1979; E.A. Bababunmi, Pig. J. Nutr. Sci. 9, ~9-63, 198~. Acetylator status of an individual determined by the activity of N-acetyl transferase and this enzyme is noninducible and polymorphic. The enzyme catalyses the biotransformation of several therapeutic drugs, biogenic amines and environmental toxins. In this laboratory we have carried out investigations on acetylation phenotyping among healthy, sicklers and individual Nigerian-Africans with glucose-6-phosphate dehydrogsnase variants in Western Nigeria. Among these three groups, the percentage of slow acetylator phenotypes are 4~.@%, 39.~6 and 38.1% respectively (L.H. Jeyakumar and M.R. French, Toxioel. Lett. 6, 263-26~, 1980; Xenobiotica 11, 319-321, 1981; Xenoblotica 16, 1129-1132). Very little is known about the role of any intrinsic genetic factor such as acetylator status in the development of Kwashiorkor, particularly since not all the children who live in Nigeria and who are on similar diets develop the nutritional disease. As a consequence we have extended our studies on acetylation polymorphism to Kwashiorkor patients and our preliminary findings on the acetylator status in Kwashiorkor disease indicate that the development of P ~ can be dependent in part, on the acetylater status of the Nigerian African. Department of Biochemistry, Sections of Drug Metabolism (Genetic Toxicology; L.H.J.) and Biomembrane Research (E.A.B.), University of Ibadan, IBADAN, NIGERIA.

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THE RELATIONSHIP BETWEEN ACETYLATOR PHENOTYPE AND IDIOPATHIC SYSTEMIC LUPUS ERYTHEMATOSUS IN A MALAYSIAN POPULATION M. L. Ong~ T. G. K. Mant~ K. Veerapen 7 D. Fitzgeraldy F. Wang, J. Bosoo and M. Manivasagar An association between host aeetylator phenotype and spontaneous systemic lupus erythematosus (SLE) has been sought for over a decade. It has been suggested that aromatic amines or hydrazine compounds that may be present in the food supply and environment may induce some cases of the "idiopathic" form of the disease in slow aoetylators (Reidenberg, M.D. AmJ Med 75:10371042, 1983). The aim of this study was to determine if there was an association between acetylation phenotype and SLE in 99 Malaysian patients. Acetylation phenotype was determined using the plasma monoaeetyldapsone (MADDS) to dapsone (DDS) ratio of Philip et al. (Br J Clin Pharmac, 17, 465-469, 1984). Slow aoetylators were defined as subjects with a plasma acetylation ratio (MADDS/DDS) less than 0.30. The distribution of slow acetylators among subjects with SLE and controls for Malaysian Chinese, Malays and Indians is summarised in the table Chinese Malay Indian Cases Controls Cases Controls Cases Controls Slow aeetylators(%): 11(13) 15(20) 5 ( 3 8 ) 6 (29) 2(67) 6(55) Total : 83 75 13 21 3 11 There was no significant difference in the incidence of slow acetylators between oases and controls in the Chinese and Malays. There were too few Indian subjects to make a valid comparison. Department of Medicine, Faculty of Medicine, University of Malaya, 59100 Kuala Lumpur, Malaysia.

ACETYLATOR PHENOTYPE AND CONGENITAL MALFORMATION M. B a r t h ~ i m e b s i , G. I Stoll 2 , M~P. R o t h2 , B. Dott 2 ,

N. Doumit , M. Welsch , J.L. Imbs Certain spontaneous disorders as Gilbert's syndrome, diabetes and even breast cancer are associated with pharmacogenetic polymorphism. We tested the hypothesis that the maternal aeetylator phenotype could predispose to congenital malformations in the fetus. A c e t y l a t o r p h e n o t y p e s were e s t a b l i s h e d for normal caucasean controls women and for mothers of malformed children by measuring urinary sulphadimidine and its acetylated metabolite. An other control group were the fathers of the malformed newborn. A figure of 75% urine sulfadimidine aeetylated has ~een taken as the dividing line b e t w e e n the slow and the fast acetylator phenotypes. 49 out of i00 control w o m e n were rapid aeetylators. The m a l f o r m a t i o n s studied were facial cleft, spina-bifida and congenital heart diseases. We verified that the acetylator phenotype is not modified during pregnancy. A m o n g s t the 108 mothers of m a l f o r m e d children, 56 (52,8%) were slow aeetylators; 42 out of 83 (50,5%) of the fathers of malformed were slow acetylators and 41 (49,5%) were fast acetylators. 15 out of 25 mothers of children with cleft lip were slow acetylator (60%) and i0 were fast aeetylator, but this difference was not statistically significant. Our study demonstrated that the acetylator phenotype of the mothers of malformed children is not different from ~he acetylator phenotype of controls. Institut de Pharmacologie (URA DO 589 CNRS), Facult@ de M4decine, Universit@ Louis Pasteur et Service d'HTA, CHRU; 2Institut de Pu4riculture, CHRU, 67000 Strasbourg, France.

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THE ABILITY TO ~ X Y I A T E DEHRISOQUINE IS REIATED TO RE~CE OF BLADDER CANCER IN PATIII%q~ WITH NONAGGRESSIVE H I S T O P A T H O ~ R.A. Branch, A. Kaisary, D.G. May, P. Smith and GR. Wilkinson We have previously suggested that high activity of debrisoquine (DB) oxidation is associated with the developn%ent of aggressive bladder cancer and suggested that this drug metabolizing enzyme might be responsible for production of a proximate carcinogen from a procarcinogen. In the present study, phenotypic indices of DB and S-mephenytoin (M) oxidation have been measured in 63 patients with non-aggressive bladder cancer (NABC) and 101 controls (C) following simultaneous oral administration o f DB (i0 mg) and M (I00 rng), at the time of diagnosis. DB, 4-hydroxydebrisoquine and the enanticm~ric ratio of M were measured in the subsequent 8 hour urine collection. Patients were followed with routine cystoscopies to time of tumor recurrence, death or a minimum of 3 years. At the time of diagnosis, DB activity was bJmodally distributed with similar distributions in NABC and C. 32 patients with NABC had tumor recurrence. DB activity was significantly greater in patients with tumor recurrence in c c ~ i s o n to those with no recurrence, while no difference between groups was observed in M activity. Kaplan-Mier time curves indicated that patients in the lowest tertile of DB activity had longer survival than in middle and upper tertiles (p=0.05). The observations are consistent with the hypothesis that the DB hydroxylase contributes to formation of proximate carcinogens in patients with non-aggressive bladder cancer and contributes to tumor recurrences. Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232 USA and Department of Urology, University of Bristol, Bristol, Avon, UK.

METABOLISM OF D E I ~ _ I S ( ~ , MEPHI~]YTOIN AND DAPSONE IN SCLERODERMA D.G. May, C. Black, N. Olsen, M E . Csuka, B. Tanner, G.R. Wilkinson and R.A. Branch Exposure to certain envirorm~_ntal toxins can induce a scleroderma (S) -like syndrome. However, the contribution of environmental factors to idiopathic S is unknown. One possible mechanism is that a protoxin is converted by hepatic drug metabolizing enzymes to a proximate toxin that initiates S. This hypothesis would predict that the frequency distribution of activity would be higher in S than controls (C) if the enzyme produced the toxin, or be lower if it produced alternative non-toxic metabolites. We have tested this hypothesis using previously described phenotype indices of drug metabolizing activity in 87 patients with S and 107 C following simultaneous oral administration of debrisoquine (DB) (i0 mg), mephenytoin (M) (1GO mg) and dapsone (DA) (50 r~]) and collecting the subsequent 8 hour urine for measllrement of parent drug and metabolites. DB exhibited a bimodal distribution that was similar in S and C. M also exhibited a bimodal distribution, with 16 and 9 of the subjects being poor metabolizers in S and C, respectively (p
OP 14.05

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DEPkLIS(I~-TYPE OXIDATIVE PHKN(51ATE IN dilI/)RD~WITH AND WITHOJf CANCI~R. M.V. Relli1~_W~P: Petros, W.R. Crom~ M.J. Schell, B. Sin~% S:_J. .Foelps, R.A. Helms~W. E. Evans. Although the debrisoqwin-tlypegenetic polymerphismof cytochrome P450 drug metabolism has been well characterized in several adult populations, there is a paucity of data in children, and no data on pediatric cancer populations. Our objective is to characterize debrisoquin-type oxidative pher~types in children with cancer, a group of their siblings, and children without cancer, using dextromethorphan (DM) as the prototype substrate for this polymorphim~. We collected a pre-dose urine, administeredDM 30 rag orally, and collected urine for 4 hours after I]4 administration in 373 childre~ with acute lymphocyticleukemia (ALL), with a variety of other tlmmrs, in the siblings of childrenwith car~er, and in a group of healthy children without cancer. The children within each of these 4 groups were u~related. Complete 2-week medication histories were obtained in all subjects, An aliquot of urine was assayed by HPLC-UV for EM and the polymorphic metabolite, dextrorphan (DT). The metabolic ratio was calculated as the molar concentrationratio of [~/DT; the antimode used to discriminate extensive (~4) from poor metabolizers (PM's) was 0.39 Ages r~nged from 1.9 to 19.8 years. The prevalence of the PM phenotype ( r ~ r of PM's/total nt~ber of subjects in e~ch group) was: 5.3% (6/114) for childrenwith ALL; 6.4% (5/78) for the other t~mors group; 6,4% (4/63) for siblings; and 3.4% (4/118) for children without cancer. These prevalenees did net differ significantly from each other (p=0.75). The prevalence of the PM phenetype also did met differ significantly ~ n g children when they were divided into age groups: 6,8% (4/59) for 0-5 years, 5.0% (9/180) for 5-10 years, 4.1% (4/97) for 10-15 years, and 5.4% (2/37) for 1520 years (p=0.91). Although larger r ~ r s of children must be studied to confirm these preliminary findings, we conclude that there is no difference in IIM oxidative phenetype distribution arf~ng children with cancer, their siblings, or children without cancer. In addition, these data suggest that there are not age-related effects on debrisoquin hydroxylase metabolism of this substrate in children of this age range. St. Jude Children'sResearch Hospital, 332 N. lauderdale, Memphis, IN 38105, and University of Te~ssee, USA.

GENETIC TRAITS OF FOREIGN COMPOUND METABOLISM AS PREDISPOSING FACTORS OF BRONCHIAL, LARYNGEAL AND PHARYNGEAL CARCINOMA I. ROOTS, N. Drakoulis, M. Cuprunov,J. Brockm611er,M. Nitz Many of the enzymes functioning in foreign compound metabolism exhibit an inherited polymorphism that might influence the balance of toxification and detoxication of carcinogens. In an attempt to characterize persons with an increased or decreased risk towards certain kinds of cancer, the prevalence of the high or low activity phenotypes of the cytochrome P-450dbl isoenzyme and the N-acetyltransferase was evaluated in patients with lung, larynx,or pharynx cancer as well as in matched reference patients without known cancer. METHODS: 5-10 mg of debrisoquine (D) were given orally for hydroxilator phenotype determination. A metabolic ratio MR ~ 12 of D/4-0H-D in 5-h urine indicated the poor metabolizer status (PM). Acetylator phenotyping based on the ratio of 5-acetylamino-6-formylamino-3-methyluracil (AFMU) and l-methylxanthine (IX) in urine after coffee intake. Ratios of AFMU/IX < .48 represent the slow acetylator phenotype. RESULTS: Among 301 patients with bronchial carcinoma, 7 % PMs were found (95 % conf. limits: 4.3-10.5 %) in contrast to 10.6 % (7.4-14.7 %) in the matched control group. This difference is of marginal statistical significance. An underrepresentation of PMs was found in patients with adenocarcinoma (I out of 46; P=.020) and in patients not older than 50 years (none out of 37; P=.047). The prevalence of slow (49.1%) and fast (50.9 %) acetylators corresponded to that in the control group. Among 102 patients with larynx carcinoma, 4,9 % PMs were detected as compared to 10.8 % in the matched control group. PM frequencies in pharyngeal cancer patients (n=l15) and in matched controls resembled each other (9.6 % vs. 10.4 %). CONCLUSIONS: The diminished frequency of PMs among bronchial and laryngeal cancer might propose this genetic trait as a host factor protecting from these kinds of cancer. However, greater numbers of patients, to enable proper stratification, and other methodological approaches should be applied for final elucidation. Institut ffir Klin. Pharmakologie, Klinikum Steglitz, Freie Universit~t Berlin, Hindenburgdamm 30, D-1000 Berlin 45

A 62

OP 15.01

OP 15.03

COMPARATIVE STUDIES ON HEMODYNAMIC EFFECTS OF INTRAVENOUS MEXILETINE, LIDOCAINE AND DISOPYRAMIDE IN SAMZ PATIENTS

DO METABOLITES CONTRIBUTE TO THE /3-BLOCKING EFFECTS OF PROPAFENONE? H.K. Kroemer, D.J. Silberstein, AJ.J. Wood and D.M. Roden. Propafenone (PPF) is an antiarrhythmic drug which produces variabJe #-blocking effects in patients and which undergoes extensive metabolism to 5-hydroxy PPF and to a lesser degree to N-desalkyl PPF. The metabolites and PPF are approximately equally potent sodium channel blockers; however studies in patients have suggested that the/3-blocking action correlates well with plasma concentrations of PPF alone. Since the /3-blocking potencies of PPF metabolites are unknown, we investigated the ability of PPF, 5-hydroxy PPF and N-desalkyl PPF to displace lzsIIodopindolol from /3~ receptors on human lgmphocytes (n=5):

M. Katagiri, T. Yamamoto, S. Fukuzawa and S. Ozawa This study was designed to compare the hemodynamie effects of intravenous mexiletine to those of lidocaine and disopyramide in the same patients. The subjects consisted of Ii patients (aged 48 to 75 years) with acute myocardial infarction, All of them presented regular sinus rhythm. Heart rate (HR) was measured by ECG and blood pressure was measured from radial artery. Pulmonary arterial pressure and cardiac output were measured by Swan-Ganz catheter. All parameters were measured prior to and immediately after medication. Serum mexiletine concentration was measured by method of Gas-Chromatography. Mexiletine, lidocaine or disopyramide of i00 mg were administered intravenously over a period of 5 minutes at the separate times. After mexiletine, there were no significant changes in all measured hemodynamie parameters. Serum mexiletine concentration was 0.92• g/ml (ranged 0.72 to 1.69 ~g/ml). On the contrary, lidocaine increased diastolic blood pressure (DBP), pulmonary arterial endo-diastolic pressure (PAEDP) significantly to 107• 143• and decreased cardiac output to 93• of the controlled values, respectively. Administration of disopyramide results in significant increases of HR, DBP and PAEDP to i15• i16• and 181• with significant decreases in systolic blood pressure and cardiac output to 94• 78• respectively. In conclusion, intravenous mexiletine did not cause any adverse effects on hemodynamics and was the safest in patients with acute myocardial infarction comparing to lidocaine and disopyramide. Department of Internal Medicine, Funabashi Municipal Medical Center, 1-21-1, Kanasugi, Punabashi, Chiha 273, Japan

'L'~L,.

lO0

~

~ '-..'~'-~.

"6.

80

l

a, 5 - h y d r o x y PPF o N - d e s a l k y l PPF

"

•

~5

,_.u ~

40

o :> o. co

20

&"

"'A

o 9

8

7

-Ioglo[Propafenone],

6

5

M

PPF had the highest affinity (Ki=12• nM), followed by Ndesalkyl PPF (Ki=37+15 riM) and 5-hydroxy PPF (Ki=181:~61 riM). These findings provide direct confirmation of the suggestion from clinical data that 5-hydroxy propafenone is unlikely to contribute to the /3-blocking effects of propafenone in man. Departments of Medicine and Pharmacology, Vanderbilt University, Nashville TN 37232, USA

OP 15.04

OP 15.02 T H E E F F E C T OF A M I O D A R O N E PHARMACOKINETICS

ON

DISSOCIATION OF MULTILAMELLAR INCLUSION BODIESAND CELL

LIDOCAINE

H. H, Rotmensch, K. K, Flaharty, C. Hefeli, E. Graf, A. Nissimov, P. H. Vlasses The antiarrhythmic amiodarone (A) alters the disposition of several other cardiovascular agents primarily by inhibiting hepatic microsomal enzymes. Patients with resistant arrhythmias may receive A and the antiarrhythmic lidocaine (L). To evaluate the effects of A on the disposition of L, eight adult patients with ventrieular or supraventricular arrhythmias with no evidence of CHF, liver failure or renal failure, were given an intravenous bolus of L (150mg) before and after A (1200 mg/day orally for 3 days). Serial blood samples over 210 minutes were obtained following each bolus and plasma L concentrations were determined by HPLC. The mean (SD) data were:

TI/2(Hr) CL(L/Hr) Vdss (L), AUC(mg/L.min)

n PPF Z

L alone

L with A

1.85 39.2 80.3 287

1.53 34.7 70.5 312

(0.79) (19.9) (28.5) (166)

(0.76) (;4.S) (40.0) (154)

A had no statistically or clinically significant effect on L disposition. E. Wolfson Medical Center, Dept. of Medicine, P.O. Box 5, Holon 58100, Israel

TOXICITY OF AMIODARONEAND OTHERANTIARRHYTHMIC DRUGS IN HEPATOCYTES IN PRIMARYTISSUE CULTURE P. Somani, S. Bandyopadhyay,and J.E. Klauniq Amiodarone CAM), a class I l l antiarrhythmic drug is highly effective in controlling life-threatening arrhythmias. The mechanism of its toxic effects on the l i v e r and other organs in inducing intracellular inclusion is unknown. We investigated the direct effect of various conc of AM, its major metabolite, desethyIAM (DA), and several cationic amphiphilic drugs (propranol o l , verapamil, procainamide, sotalol, and atenolol) on primary hepatocytes in tissue culture. Release of hepatic enzymes (lactate dehydrogenase, LDH) and formation of intracellular inclusions by electron microscopy was determined after 24 hr incubation. Only DA, AM, propranolol, and verapamil induced a conc-dependent release of LDH with calculated LDso of 20• 50• 224• and 220• #M, respectively. Transmission electron microscopic data showed formation of intracellular multilamellar inclusions in conc (~M) which did not cause col] death: AM=7.6, DA=8; propranoloi=12.5-25; verapamil= 12.5-25. Scanning electron microscopic pictures showed numerous blebs on the external surface of the hepatocytes with sublethal drug concentrations. These data suggest that (i) DA is more toxic than AM; (2) only highly l i p o p h i l i c cationic amphiphilic drugs induce intracellular inclusions in hepatocytes; (3) with low drug conc, we can show induction of multilamellar inclusions without release of excess LDH or cell death; (4) bleb formation without release of LDH suggests another mechanism of t o x i c i t y via effects on cytoskeleton; (5) these data confirm our clinical observations that intracellular inclusions in myocardial cells or WBCs are seen in the absence of signs or symptoms of clinical t o x i c i t y (Brit. J. Clin. Pharmacol. 24:237, 1987). Medical College of Ohio, P.O. Box 10008, Toledo, Ohio 43699-0008 USA

A 63

OP 15.05

OP 16.02

EFFECTS OF VERAPAMIL (V) ON HEPATIC BLOOD FLOW IN CONSCIOUS DOGS M-F. Doursout, P. Wouters, A. Varughese, C. Lawrence, R.G. Merin, and J.E. Chelly The elimination characteristics of V depend primarily on changes in hepatic blood flow. In basally anesthetized dogs undergoing laparotomy procedures, V-induced dosedependent decreases in cardiac output and hepatic blood flow have been demonstrated. These findings suggest that V decreases its own e l i m i n a t i o n . To avoid the deleterious effects of basal anesthesia and surgical stress, we investigated the pharmacokinetics of V and its dependence on hepatic blood flow in conscious dogs. Eight mongrel dogs were chronically instrumented for measurement of cardiac output (CO), heart rate (HR), mean arterial pressure, hepatic blood flow, and portal blood flow (PBF). V was intravenously infused in a dose of 200 ug/kg over I0 minutes. Hemodynamic measurements and arterial samples for the determination of V plasma concentrations were obtained before and I, 3, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min following end of infusion in conscious dogs. Plasma V concentrations were measured by reverse phase high pressure liquid chromatography. Maximum effects were recorded at 1 min following V infusion. V significantly increased CO (+0.30 + 0.I liter/ min), HR (+34 + 2 bts/min), PBF (+57 + 17 m~/min), and total hepatic b--lood flow (+85 ~ 31 mlTmin). V pharmacokinetic parameters are presented in the following table. Clearance Volume of Distribution Elimination Half-life liters/hour liters hours 30+3 61+9 2.0+0.20 These data show evidence that V-induced hemodynamic changes do not negatively affect V elimination. Our findings are of special interest considering that V plasma concentrations (188 ~ 15 ng/ml) are within the clinical therapeutic range.

AMLODIPINE DISPOSITION AND DYNAMICS IN ELDERLY HYPERTENSIVE PATIENTS D. R. Abernethy and M. D. Lambert Fifteen elderly (mean• age 68• yr) and 13 young (35• yr) hypertensive patients received single intravenous amlodipine doses (elderly 2.5mg-n=6, 5mg-n=3, 10mg-n=6; young 10mg-n=13). Amlodipine concentrations were determined in multiple plasma samples obtained during the 96 hours following drug administration. Elderly patients had significantly prolonged elimination half life (t89 (57.8• vs 42.2• hr; p<0,01) compared to young patients. This was the result of decreased total clearance (18.8• vs 25.4• L/hr; p<0.01) with no change in volume of distribution at steady state (1490• vs 1418• L; NS). Calculated mean residence time for amlodipine was also prolonged in elderly patients (82.3• vs 56.9• hr;p<0.Ol). Comparison of mean arterial pressure (MAP) at the lOmg dose for both groups indicated greater decrease in the elderly patients at 4 hours (-28• vs -I0• mmHg; p
Dept. Anesthesiology, Baylor College of Medicine, i Baylor Plaza, Houston, Texas, 77030, USA

OP 16.01

OP 16.03

FELODIPINE EXTENDED RELEASE TABLETS GIVEN AS MONOTHERAPY TO ELDERLY HYPERTENSIVE PATIENTS. EFFECTS ON BLOOD PRESSURE. C. Swift, J. Arnold, B. Edgar, and J.Hosie Feiodipine (F) (Plendil| is a calcium antagonist which selectively reduces the contractile activity of the resistance vessels in smooth muscle. The aim was to investigate the effect on blood pressure (BP) over a dosage interval after 2 and 4 weeks. An extended release (ER) formulation of F, 5-10 mg, given o.d. to elderly patients with mild to moderate hypertension, was compared to placebo. Methods: A two-way, single-blind, steady state study. Twenty eldedy hypedensive patients with a mean age of 75 yrs (range 68-82 yrs), 11 men and 9 women, completed the study. Existing antihypertensive treatment was withdrawn before the start of the study. After a 2 week run-in period on placebo, haemodynamic measurements were taken over a dosage interval (8 hrs). Those patients with a diastolic BP (DBP) of <95 mmHg and < 120 mmHg were included. A 10 mg acute dose of F ER was given and measurements taken over a full dosage interval (24 hrs). This was followed by a 2-week period on 5 mg F ER. Those patients with a DBP of > 95 mmHg were then given a 10 mg F ER tablet 0.d. for 2 weeks, while those patients with a DBP of < 95 mm Hg continued on the 5rag F ER tahlel o.d for 2 weeks Haemodynnmic measurements were taken up to 48 hrs on the last study day at the clinic 14 days later. Results: Initial blood pressures were 177+17/105:1:6 mmHg in the morning before the placebo dose at the clinic. BP decreased to 160+18/96:1:7 mmHg 4h after the dose. After the first 10 mg F ER tablet, BP fell from 176+16/102+9 to 143+18/77+10 4 hrs after dose without an accompanying increase in heart rate (HR). Fourteen of the pts had a morning DBP <95mmHg 14 days after the start of the study. The mean BP was 157+14/68+12 before the last dose. DBP was not decreased further dudng repeated administration compared to the first dose. There was one patient in both groups with a DBP of > 96 mmHg 24 hours after the last dose. Two pts were withdrawn from the study for compliance reasons. Two mild adverse events were reported. Conclusions: In this group of elderly pts, F ER 5 to 10 mg o.d. given as monotherapy, was very effective and well tolerated in the treatment of hypertension. King's College of Medicine & Dentistry, Dulwich Hospital, St, Francis Road, London, U.K.**

EFFEC'f OF AGE ON THE PHARMAOOKINETICS OF ZOLPIDEM (STILNOX R) A NEW IMIDAZOPYRIDINE SLEEP INDUCER. P.L. Morselli, J.P~ Thenot, C. Dubruc and G. Bianchetti Given the physiological changes related to age which may modify the pharmacokinetics of a drug, coupled with the fact that sleep inducers are likely to be prescribed to patients of widely different ages, it appeared necessary to assess the effect of age on the kinetic profile of zolpidem. Pharmacokinetic results (see table) after a I0 mg dose showed that : total body clearance of zolpidem in children is about 2-3 t i m e s greater than that observed in adults, whilst AUC and Cmax were comparable even if ~he dose/kg was 2-3 times higher than for adults. In elderly, from 60 to 95 years, clinically important modifications of pharmacokinetics were evident only in the two groups aged more than 75 years. Mainly alteration was due to the reduction of Vd, leading to higher Cmax and AUC, the reduction of the total clearance and bioavailability. The consequences of these results will be discussed. AGE GROUP

Cmax (ng/ml)

TI/2 (hrs)

AUC (ng/ml.h)

vd (I/kg)

(8-14 y)

142+29 2.0+0.3

326+63

(18-35 y)

365+50 (0.54+0.02)

(40-55 y)

142+17 2.4+0.1 (1.~0.2) 125+10 2.2+0.1

394+45

-

(60-74 y)

129+13 2.9+0.3

618+97

-

(75-85 y)

213~22 2.7~0.2

917+--227

-

(81-95 y)

238+35 2.5+0.2 1064+147 0.34+0.05

-

-

-

SYNTHELABO RECHERCHE - 23-25, MEUDON-LA-FORET CEDEX (F)

-

-

-

av.

C1 (I/h/kg) (0.86+0.10)

-

Morane

(0.26+0.03) --

0.09+0.01 Saulnier

92366

A 64

OP 16.04

OP 16.06

PREDICTION OF SERUM AMIKACIN CONCENTRATIONS IN GERIATRICS P.H.MAIRE, C.DUMAREST, D.ROUX, C.CHAUVET r E.VERMEULEN r P.COURPRON,J.L.BRAZIER, R.W.J~/ZJFFE Three methods for predicting serum amikacin concentrations in the elderly have been coapared:l)"a priori" model with one or two co~partments(APiY,AP2Y and APIG), 2)Non-linear least squares model(MLS1), 3)Bayesian model (BIY,B2Y and BIG), using young(Y) population parameters and secondly using specific geriatric(G) population parameters. For all the models Kel=Kslope*CCr+Ki. METHODS:The study examined 37 patients(mean 79 years old). For 10 paEients,2 clusters of levels were obtained: 4 levels per patient for the first fitted set and 2,3 or 4 per patient in the second predicted set (36 levels). To evaluate the ability of each method to predict the second set of levels when fitted to the first one, we used: i) a linear regression(observed versus predicted levels,squared cceff:R2), 2)the mean weighted prediction error(MWE) and the mean weighted squared prediction error (~SE) as an expression of bias and precision,using the t Student and the Mann Whitney U tests respectively as statistical methods.The parameter values of a geriatric population have been determined using MLSI with the data of 27 patients. RESULTS: Methods R2 MWE I~4SE * POPULATION PARAMETER VALUES APIY 0.581 25.0 1186 * (ONE COMPARTMENT) AP2Y 0.744 14.4 420 * YOUNG GERIATRIC MLSI 0.898 -3.8 65.5 * VFC 0.2645 0.386 L/Kg BIY 0.897 -3.6 63.9 * SD 0.052 0.1797 B2Y 0.927 2.7 82.1 * Kslope 0.002448 0.003404 /hr APIG 0.665 -6.1 161.i * SD 0.00049 0.001806 BIG 0.896 -3.6 66.8 * and Ki=0.00693 /hr, fixed The two population models (APIY,AP2Y) are very poor predictors for our geriatric patients;the population model APIG predicted significantly better than the young population models.The four fitted models(BIY,B2Y,MLSI,BIG) predicted significantly better than the population models; the best of them wes the B2Y with no significant difference. TheY are good predictors in our hospital. A.Charial's Geriatric Hospital,69340 Francheville,France.

ABSENCE OF SIGNIFICANT AGE-RELATED ALTERATIONS OF GLIBENCLAMIDE PHARMACOKINETICS : STUDIES IN YOUNG HEALTHY VOLUNTEERS, AND IN MIDDLE-AGED AND ELDERLY TYPE 2 DIABETIC PATIENTS. A.J. Scheen, C. Jaminet, M.P. Stassen, A.C. Ferreira Alves de Magalhaes, T. Salvatore} J. Gerard and P.J. Lef~bvre. Following the report of severe glibenclamide-induced hypoglycaemic episodes in elderly type 2 (non insulin-dependent) diabetic patients, we aimed at investigating the influence of age on the pharmacokinetics of this sulfonylurea compound. All subjects had normal cardiac, renal and liver functions; 6 young healthy volunteers (28 ~ i years), i0 middle-aged type 2 diabetic patients (53 ~ 3 years) and 8 elderly type 2 diabetic patients (75 ~ i years) were investigated. Each overnight fasted subject ingested 5 mg glibenclamide (Euglucon~, Boehringer Mannheim) just before a standardized breakfast (0 min). Serum glibenclamide levels were measured by radioimmunoassay from 0 to 540 min Maximal concentrations (225 ~ 31, 217 ~ 27 and 224 + 21 ng/ml respectively; NS) and areas under the curve (~9950 9193, 58885 ~ 7480 and 71456 ~ 8273 ng/ml.540 min respectively; NS) were similar in the three groups. Time-to-peak levels were highly variable between subjects (from 60 to 300 min) and were curiously delayed in young normal subjects (230 ~ 24 min) when compared to middle-aged (84 ~ 12 min) or elderly (135 ~ 21 min) diabetic patients. Elimination decay between 240 and 540 min was similar in middleaged (0.34 ~ 0.05 ng/ml/min) and elderly (0.37 ~ 0.06 ng/ ml/min) diabetic patients but somewhat greater in young healthy volunteers (0.53 ~ 0.i0 ng/ml/min)(NS). In conclusion : glibenolamide pharmacokinetics does not seem to be influenced by age itself. In the elderly patient, in the absence of intercurrent diseases, kidney insufficiency and drug interactions, the occurrence of severe hypoglycaemic episodes is likely to be better explained by errors in glibenclamide intake and/or changes in food ingestion rat-her than by modifications in the pharmacokinetic parameters of the drug. Divisions of Diabetes and Clinical Pharmacology, Dpt of Medicine, CHU Liege, Sart Tilman, B-4000 LIEGE i, Belgium.

OP 16.05

OP 17.01

EFFECT OF AGE AND FRAILITY ON DRUG CONdUGATION IN MAN. K.W. WOODHOUSE, H.A. WYNNE, L.H.COPE, B.H. HERD, O.F.W. dAMES, M.D. R A W L INS. Although studieshave shown a decline in clearanceof many oxidieeddrugs with age, littleattentionhas been paid to the influenceof old age on conjugationreactions.The effectof ageing upon the clearanceof paraeatamol, which is eliminatedlargelyas the glucuronideand sulphateconjugatesis debated. W e set out to examine the contributionof changes in a) age, b) liver size,c) physicalfrailityto changes in parasetamol elimination. Plasma clearanceof an intravenousdose (50Grog) of paracetamol (P) was measured in 19 young fit (A), 20 elderlyfit (B), and 9 elderlyfrail hospitalised(C) subjects. Urinary metaboliteexcretion was measured. Liver volumes were measured by ultrasound. Resultsare seen in the tables

NEONATAL AND ADULT ISOLATED HUMAN ALBUHINi SIMILARITIES AND DIFFERENCEStN THE BINDINGOF FUROSEHIDE Yiani: M. CeDpiello and G.M. Pacifici In order to afford the problem of differential drug bindind in neonatal and adult serum ve isolated albumin obtained from pooled serum from 58 placental cords (PC) and 8 adult individuals (A). Albumin= was isolated by precipitation with PEG 4000 followed by ton-exchende chromatndraphg on DEAE-Gephedex A 50 end 5P~;ephadex C 5U as described by Curling et el. (Yox Sang..55: 97,1977). The analysis of albumin isolated from PC and A on polyacrilamide gel showed only one band vith identical Rf of a

below; Age A 25+I B 73+I

p CI/ body weight(ml/min/kg) 4.7+.2 3.7<2*

C 82+2 2.5• *+ % excreted as: glucuronide A 45• I B 44 • 1 C 35+3 *+

P C11 liver volume ( m l / m i n / l ) 251+14 234+18 157+ 17"*

sulphate 42+ 1 39• 1 49• *+

porocetomol 13• 1 16• 1 14•

values = moans +s.e.m,p <0.01 compared to * young,+ fitelderlysubjects. ANOYA. The declinein parecetamol clearancewith age alone is accountedfor by the paralle~fallin liver volume. In the frailsubjects however, the significant fallin parasetamol clearanceper unit volume of liverand reduced excretion particularlyof the glucuronideconjugatesuggeststhat there is an impairment in the activitiesof conjugationenzymes in thisgroup. Dmmtmmt ofR~wacdog~l Sdmces,~ f s m Uritofait~ ~ , TheLttva~ty,

i,L=wcss~UponTy~,NE17RU.U.K.

commercial albumin. Binding assay yes performed vith (7-14C) furosemide (F) (purity >99 ~) at 37 C for 4 h using a Diaoorm apparatus. Bg vergind the concentration of F from 5 to 600 ug/ml, and keepind albumin at 40 g/l, the unbound fraction of the drug ranged betveen 4.2 and 16.5 (PC) and 4.1 end 14.1 (A). The bindind kinetics consist of 2 pheso~, one vith high and the other with low affinity for F. The maximun binding capacity (n, mole F/mole of albumin) for the high affinity phase ',.'as 1.Z2 (PC) and 1.56 (A) whereas the association constant (Ks) was 3.1x10 4 M-t(cp)

2.6 xlO 4 M - I ( A ) . For the lay affinity phase, nwas ,~.0

for CP and A vhereas the Ka wa~ 8.OxlO3M-I(cp)

and 11.54

xlO 5 M - I (A). Displacement of F (6uM; 2u~/ml) from albumin .,as studied vith 5 mgtml albumin and 600 uM indometacln, tolbutamide, napruxen, glibenclamide, salicylic acid, chlorpropemide (Ch), azopropazone, varfarin, valproic acid (Ya), diflunisol and 175uH diazepam, ISOuM fenytoin, 60uM dioitoxin and IOOuM bilirubin. All these drugs bad comparable displacement effect of F from CP and A with the exception of Ch and Ya vhich had significantly hlgher displacement effect vlth albumin from CP. The present data suggest that neonatal and adult human albumin have similar properties in the binding of F. Hoverer, the small differences in the kinetic parameters and also the different effect of Ch and Ya suggest that differences may exist betveen the tvo albumin. Departments of General Pathology, University of Piss, Piss, Italy.

A 65

OP 17.02

OP 17.04

THE EFFECTOF AGE ON THE SERUMCONCENTRATIONOF ALBUMIN AND ALPHA-I-ACID GLYCOPROTEIN. B.Th. Veerinq, A.G.L. Burm, J.H.M. Souverijn, Joh. Spierdijk Alpha-l-acid glycoprotein (AAG) and human serum albumin (HSA) are the two major binding proteins in serum for basic and acidic drugs, respectively. Alterations in the concentration of AAG and HSA and in the binding of drugs to these proteins can have important pharmacokinetic and/or pharmacodynamic implications. One of the factors that may affect AAG and HSA concentrations is age. However, most studies of the effect of age on AAG and HSA concentrations have been done in hospitalized patients and the results may have been influenced by superimposed systemic disease. The present study was designed to i n v e s t i g a t e the e f f e c t of age on AAG and HSA in subjects without signs of diseases, known or suspect to influence the concentrations of these p r o t e i n s . Serum was c o l l e c t e d from 68 p a t i e n t s , 35 males and 33 females, aged 20-90 yrs. Subjects were "drug f r e e " f o r at least 1 month. Medical examination and standard l a b o r a t o r y t e s t s showed no evidence of acute or chronic inflammatory disease or malignancy. They were divided into 4 groups according to t h e i r age. ( I : less than 30 years; I f : 30-49 y r s ; I I I : 50-69 yrs; IV: older than 70 y r s ) . AAG and HSA were determined with the Array Protein System (Beckman). S t a t i s t i c a l analysis (P < 0.05): one-way ANOVA and m u l t i p l e S t u d e n t s - t - t e s t with Bonferroni c o r r e c t i o n to compare the r e s u l t s in the 4 age groups. The e f f e c t o f age on HSA and AAG were f u r t h e r evaluated determined by l i n e a r regression and c o r r e l a t i o n a n a l y s i s . Results, obtained in males and females were s i m i l a r . There was a s i g n i f i c a n t c o r r e l a t i o n between HSA concentration and age ( r : -0.80, P < 0.001), but no s i g n i f i c a n t c o r r e l a t i o n between AAG concentration and age ( r = -0.044). HSA was s i g n i f i c a n t l y lower in group IV (P < 0.0001) than in group I and I I (P < 0.01); in Group I I I HSA was s i g n i f i c a n t l y lower than in group I I (P < 0.005). This study showed t h a t in healthy subjects the HSA concentration decreases with age, whereas age per se does not play a major r o l e in the AAG concentration. U n i v e r s i t y Hospital Leiden, Department of Anesthesiology, P.O. Box 9600, 2300 RC Leiden, The Netherlands.

ENDOGENOUS LIGANDS AND STRUCTURAL CHANGES INHIBIT BINDING TO HUMAN SERUM ALBUMIN IN CHRONIC RENAL FAILURE

T.J.Dengle~ G.M.Robertz-Vaupel, H.J.Dengler The binding capacity of human serum slbum)n (HSA) at the warfarin site is known to be reduced in chronic renal failure (CRF). This study evaluates the contribution of competitive inhibition by endogenous ligands and structural changes of HSA. Methods: A fluorescence test assay comprising HSA (5pmol/L) and Dansylgiycin (lpmol/L) was devised to determine the inhibitory capacity and mode of inhibition of 35 endogenous ligands accumulating in CRF. The effect of carbamylation of HSA on binding was also investigated. Binding parameters n,kA and ICs0 were calculated f o r each inhibitor. Preliminary i n - v i v o studies comparing healthy volunteers and dialysis patients were undertaken using the same assay on diluted serum. Results: Comparing maximum inhibition ligands could be placed in 4 groups: lJ no change (e.g.urea,creatinine) 2) weak inhibition (<10%, hippuric acid) 3) medium inhibition (10-50~, vanillic acid) 4) strong inhibition (>50%, indolyl acids). Inhibition was shown to be purely competitive except f o r the recently discovered furanoic acids. Carbamylation of HSA reduced binding by 68% in a noncompetitive mode lowering n from 1.05 to 0.60. In serum, fluorescence in the control group reached 88.02% + 1.02% of a reference standard. In the dialysis patients it was reduced to 66.51% + 7.24% (p
OP 17.03

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DOES THE NON-~ZYMATIC SERUMALBUMIN GLYCOSYLATION IN DIABETICS INHIBIT B~ZODIAZEPINE BINDING? EVIDI~NCE FROM FAST REACTION BINDING S~UDIES IN VITRO. S. Pfleiderer r W. W~rnerf N. Rietbrock Some properties of human serum albumin (HSA), for example the isoelectric point and drug binding affinity, are influenced by non-enz~natic glycosylation. We have used fatty acid free HSAand dansylsarcosine (DS), a model ligand for the benzodiazepine binding site, to investigate the effect of nonenzymatic glycosylation on binding kinetics9 The change in DS fluorescence on binding to HSA, measured using a Durr~n-Gibson Stopped-Flow apparatus, was used to derive the affinity constant (KA) and the velocity constants for association (k2) and dissociation (k_2). When the glycosylation rate of HSA was increased from 7.5% to 100% the affinity constant was reduced by 86%. The change in K A W a S caused by a decrease of 75% in k 2 and an increase of 58% in k_ 2 (Tab. l). Tab.l: Bi~ding parameters of HSA related to rate of glycosylation

BINDING OF THE VOLATILE ANAESTHETIC HALOTHANE TO HUMAN PROTEINS P. Altmaver, U. Btich and H.P. B~ich*

Glycosylation rate (%) 7.5 k 2 (s-l) 518.3 k_ 2 (s~ I ) 13.2 KA (10 ~ i/mol) 9.4

50 279.2 18.6 2.9

100 128.5 20.9 1.4

This modification of DS binding at the benzodiazepine binding site of HSA represents an 8-fold rise in the free fraction of DS. Recent studies using HPLC I showed that HSA glycosylation in diabetic patients may be as high as 50%9 A glycosylation rate of this magnitude in vitro caused a 2-fold rise in the free fraction of Eke. Therefore the benzodiazepine dosage in such ~Ktients may need to be reduced. 9 Shima et al, Diabetologia (1988) 31: 627-631. Abt9 Universit~tsklinik Frankfurt, Theodor-Stern-Kai 7, 6000 Frankfurt/Main 70

The volatile anaesthetic halothane (H) is bound to human serum albumin (HSA)(Altmayer et al., Anaestbesist 36(Suppl.), 447, 1987). In order to investigate the binding characteristics of H to human proteins (hemoglobin=HHb,7-globulin=HSG) a new method(based on equilibrium dialysis) was developed which allows very precise and reproducible binding studies with volatile compounds. Phosphate buffer (PB) and protein-solution (PS) were pumped in two closed systems through a dialyzer ("artificial kidney") with an exchange surface of 1.8 m2. The PB was circulating through an "oxygenator" (clinically used for the oxygenation of blood in the heart lung machine, exchange surface 5.4 m 2) whose gas supply was passing through an H vaporizer by which the entire system was equilibrated at a desired H concentration. At steady state samples of both systems were taken by puncture through self-sealing septa and injected immediately into an HPLC analytical system, which was based on pre-column extraction allowing the determination of H in biological fluids without any workup of the sample. The difference cf the H conczztration; ;a the PI1 and ?S system at steady state indicates the binding of H to the proteins and the percentage of H bound Can be evaluated for any H concentration setted to the vaporizer in the same protein solution. H was bound to a higher percentage to HSA then to HHb; a binding of tt to HSG could not be seen. The binding of H on HSA and HHb was characterized by two classes of binding sites, whereby the association constants for the two proteins were very similar. The higher percentage of H bound to HSA as compared to HHb resulted from a larger binding capacity of HSA (the number of binding sites of both classes were about ten times higher compared to those of HHb). This finding of a saturable, "specific" binding of the volatile H to human proteins disagrees with the classical concept of a partition coefficient generally applied for volatile anaesthetics. Ins~itut for Anaesthesie, Institut for Pharmakologie and Toxikologie , Universit~it des Saarlandes, D-6650 Homburg/Saar, FRG

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OP 18.02

CEETRIAXONE PHARMACOKINETICS IN MEMB3P~NE PLASMA EXCHANG~ JfDrinovec ~S. Primo~i~2j. Varl !R. Karba, R.Ponikvar ~A.Mrhar Four-compartment pharmacokinetic model featuring drug protein binding and renal, nonrenal as well as extracorporeal elimination was constructed on the basis of literature data and pilot clinical Pharmacokinetic study. Ceftriaxone(C) levels in plasma and plasmafiltrate were measured and modeled (Fig. I) following I g i.v.dose under conditions of varying the time of onset and duration of membrane plasma exchange (MPE),under normal renal function and terminal renal failure, and under conditions of returning salinic or protein substitution solution. Obtained were simulated levels of drugs which exert different degrees of plasma protein binding (Fig.2) reflecting the influence of MPE on disposition kinetics. Obtained evidence shows that MPE influences the disposition kinetics of drugs which are bound 50 % or more to plasma proteins.The elimination of highly bound drugs(i.e. 50 % or more) through M P E is important especially under conditions of diminished liver function. The presence of proteins in substitution fluid during MPE appears not to be important for disposition kinetics of C. ~_. _-~ ..................

Fig.1.C levels in plasma Fig.2.Simulated levels of (Curve=model response, drugs bound to varying extent points=experimental data) to plasma proteins under including MPE period, conditions of MPE. University E.Kardelj,IUniversity Medical Center, Dept. of Nephrology,61000 Ljubljana, Zalo~ka 7, Yugoslavia 2Dept.of Pharmacy, 3Faculty of Electrical Engineering

TARGETING PLASMA CONCENTRATIONS (Cp) OF CANCER CHEMOTHERAPY: CONTINUOUS INFUSION CYTARABINE (ARA-C) AND ETOPOSIDE (VP-16) IN THE TREATMENT OF ACUTE NONLYMPHOCYTIC LEUKEMIA (ANLL) W.R. Crom, J. Mirro, T. Madden, W.P. Petros. and J.K. Belt The dose intensity of cancer chemotherapy influences the effectiveness of treatment for a number of drug-sensitive tumors. Similarly, variability in drug clearance and resulting systemic exposure has been shown to influence response to therapy and toxicity in patients receiving identical drug dosages. The current study was undertaken to minimize interpatient variability in Cp of two important antineoplastie drugs used to treat ANLL, Ara-C and VP-16. Patients were treated with six drug pairs over a period of 6 to 9 months~ with four courses each of Ara-C and VP-16. Both drugs were administered as a continuous infusion over 96 hrs at an initial dosage of 500 mg/m2/day, with a 70 mg/m 2 loading dose over i hr for VP-16. Target Cp were 1.0 #M for Ara-C and 30.0 #M for VP-16. Blood samples were obtained at i and 6 hrs after initiating the infusions, and Cp were immediately determined by HPLC. Clearance was estimated and a new dosage calculated and implemented by 12 hrs of infusion. Follow-up Cp were determined at 24, 48, 72, and 96 hrs. For the first course in 30 patients, mean (SD) Cp of VP-16 at the end of the loading dose were 28.7 (6.7) #M, and 26.5 (3.7) #M at 6 hrs. After dosage adjustment in 17 patients, the 24-hr Cp was 30.0 (5.1) #M. For 25 courses of Ara-C, the mean (SD) Cp were 0.58 (0.30) #M at I hr, 0.86 (0.39) #M at 6 hrs, and 0.96 (0.32) #M at 24 hrs, following dosage adjustment in 26 patients. These results demonstrate the feasibility of adjusting drug infusion rates for these antineoplastie drugs to achieve target Cp and reduce interpatient variability in systemic exposure to these agents. Pharmaceutical Division, and Departments of HematologyOneology, and Clinical and Biochemical Pharmacology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; and the Departments of Clinical Pharmacy and Pediatrics, University of Tennessee. Memphis, USA

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TIG~@ILY IKYJND 5~THOTRIQ~TE (~[fX) 1%4 T ~ URI~IE OF PATII~[fS ON HIGH-DOSE THI~RAPY H. Iven r V. Kurowski and A. Wegener Seln~n of patients on high-dose MTX t~lerapy contains some ~flX that is strongly bound and can only be determined by an enzymatic assay (using dihydrofolate-reductase, DHFR) after precipitation of serum proteins. During chromatography on a Sephadex G75 co!Linen, the binding principle eluted from the column with t/%e same retention time as bovine DHFR and an ~I~-DIEY{ ccmplex obtained from rat liver after MTX-pretreatment. The complex declines in patient serum with a half-life of approx. 20 h (Cancer Treatm. Rep. 69, 825, 1985). We looked for this complex in urine samples of 3 p~tients on high-dose ~s therapy: I. osteosarcc~a (~2 g/m z in 4 h) II. medulloblastoma and III. ALL (4 g/m z in 24 h). 12 urine fractions (4 h each) were collected after start of ~IfX infusions. MTX concentrations in urine were dete~nnined by HPLC after protein precipitation, representing total amounts of excreted drug. 50 % to 70 % of ~FfX dose was regained unchanged in 48 h urine. Aliquots of the urine fractions v~re concentrated by ultrafiltration and dialysed to reduce the concentration of free ~ X . In dialysed samples 5~X concentrations were determined directly and after protein precipitation by an enz3anatic assay. ~]e difference was taken as bound 5~ID[ and the amount was calculated for each urine fraction. In patients II and III the excretion rate of bound MTX was highest 16-24 h after start of infusion and then continuously declined. Total amount of bound MTX in 48 h urine ranged between 80 and 180 pg (n = 6). In Patient I highest excretion rate was always found in the first urine sample, total amount ranging between 600 and 2300 ~g (n = 3). There sesus to .be a correlation between plasma concentrations of bound [~?IXK and its urinary excretion. To prove the identity of the binding principle, antiboc]ies against reccmbinant human DHFR (rh-DHFR) were raised in rabbits and iarmLnoblots performed. No rh-Dl{~?. inmunoreactive material was found in processed sert~n and urine s~nples of patients, strongly suggesting that the binding principle is not DI~R.

POPULATION PHARMACOKIN ETICSOF ARA-C tN AML PATIENTS. H. Friedman, L. Oliver, R. Capizzi and G. Royer 155 patients with the diagnosis of AML received an induction dose of 200 mg/m2/d ara-C by continuous IV infusion (CI) for 7 days. 13 patients who failed to go into remission received a second course of induction. Subjects were then randomized to receive 1 of 5 regimens for post-remission intensification: 100, 250,350, 400 mg/m2/d ara-C by CI for 5 days or 3 g/m2 IV over 3 hrs q 12 hrs for 6 doses, days 1, 3 & S. Intensification occurred monthly for 4 months. Plasma samples were obtained at steady state during the CI phases and at various times during the 3 g intensification phase. All plasma samples were stored with THU and assayed by RIA. Mean plasma levels for ara-C during infusion were: Dose/m 2 N Mean + SD (pM) Ranqe (pM) 100 mg 22 0.20 f 0.08 0.09 - 0.44 200rag 1SS &32 f 0.16 0.07- 1.20 250rag 2 0.36 • 0.01 0.35-0.37 350rag 3 0.75 -+ 0.06 0.71-0.82 400mg 39 0.72 + 0.35 0.24- 1.98 3g 29 12.49 + 5.21 5.11-21.87 The 17-fold range in steady-state plasma ara-C concentrations in the induction group (200 mg dose) suggests that monitoring plasma ara-C levels may allow for better individual titration of dose to achieve optimal therapy. Mean plasma levels were increased non- linearly in the 3000 mg group. Mean plasma clearance of ara-C was greater for the 200 mg dose than for the 3 g dose (2.17 -+ 1.03 vs 1.67 -+ 0.80 L/rain/m2 P < .01). Some of the subjects who received 3 g of ara-C had detectable levels up to 36 hours post-dose. Levels of ara-U, the major metabolite of ara-C, were greatly elevated during the 3 g dose phase. High levels of ara-U can inhibit ara-C renal clearance aswell as systemic cytidlne deaminase activity. The high levels of ara-U may explain in part the high levels of ara-C seen here. The elevated and prolonged levels of ara-C seen following 3 g doses may enhance the drugs penetration into tumor cells thus explaining the greater efficacy as well as higher incidence of CNS toxicity associated with high-dose ara-C. The Upjohn Company, Kalamazoo, Michigan 49001, USA.

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Institut f[ir Pha~nnakologie, Hedizinische Universit~t Lilbeck, P~tzeburger Allee 160, D-2400 Ldbeck, FRG

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OP 18.04

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6 - M E R C A P T O P U R I N E M E T A B O L I S M AND TREATMENT OUTCOME IN CHILDHOOD L Y M P H O B L A S T I C LEUKAEMIA. L. Lennard and J.S. Lilleyman. The clinical p h a r m a c o l o g y of 6 - m e r c a p t o p u r i n e (6-MP) has been studied in a single centre over an 8 year period. Intracellular 6 - t h i o g u a n i n e nucleotides (6-TGN) are the major cytotoxic m e t a b o l i t e s of 6-MP. Red blood cell 6-TGN c o n c e n t r a t i o n s were m e a s u r e d in a group of 103 children w i t h acute lymphoblastic leukaemia (ALL) to assess inter-patient v a r i a b i l i t y and its c l i n i c a l importance. The children studied were all on s i m i l a r 2 t h e r a p y w i t h a daily target 6-MP dose of 75mg/m following the p r o t o c o l of UKALL 8 or U K A L L 10. Assays w e r e p e r f o r m e d after at least two months 6-MP c o n t i n u i n g c h e m o t h e r a p y and a mini um 7 days u n a t t e n u a t e d protocol dose of 75mg/m ~. Observed 6-TGN ~ o n c e n t r a t i o n s ranged from 126 to 832 pmol/8 x i0 red cells (median 269). There was a c o r r e l a t i o n between 6-TGN and n e u t r o p e n i a 14 days p o s t - a s s a y (r = -0,48; p<0.0005), and , s an znverse correlatzon between 6-TGN and the length of time u n i n t e r u p t e d full protocol dose was tolerated w i t h o u t n e u t r o p e n i a (r = -0.3; p<0.01). After a median follow up o~ 48 months, 17 c h i l d r e n have relapsed of w h o ~ 16 had 6-TGN assays b e l o w the group median (X = 12.8; p<0.0005). Six have died in remission, 4 with 6-TGN above the median, but despite this the p r e d i c t e d advantage in event free survival at five years for those above the median is still 28% (95% C.I. 8 to 48%~ p<0.01). Children w i t h A L L taking the same dose of 6-MP show great v a r i a b i l i t y in its m e a s u r a b l e eytotoxic effect, and this v a r i a b i l i t y is a p p a r e n t l y related to treatment outcome. Univ. Dept. P h a r m a c o l o g y and Therapeutics, Royal H a l l a m s h i r e Hospital, Sheffield, S10 2JF, UK.

CELLULAR PHARMACOKINETICS OF DAUNOMYCIN IN HUMAN t~UKEMIC BLASTS IN VITRO AND IN VIVO M. E. Scheulen a ~ i c h The d e t e r m i n a t i o n of c e l l u i a r tumor pharmacokinet i c s and metabolism o f c y t o s t a t i c drugs may be of g r e a t v a l u e f o r the d e t e r m i n a t i o n of i n d i v i d u a l drug s e n s i t i v i t y and f o r the o p t i m i z a t i o n of the t r e a t m e n t schedule. In the c l i n i c , c e l l u l a r tumor p h a r m a c o k i n e t i c s and m e t a b o l i s m can o n l y be measured in p e r i p h e r a l leukemic b l a s t s w i t h o u t major d i s c o m f o r t f o r the p a t i e n t s . We have d e v e l o p e d a method f o r the i s o l a t i o n of p e r i p h e r a l leukemic b l a s t s w i t h subsequent e x t r a c t i o n of daunomycin and q u a n t i t a t i v e a n a l y s i s by HPLC w i t h f l u o r e s cence d e t e c t i o n . Up t o now, c e l l u l a r tumor phar ~ m a c o k i n e t i c s and metabolism was s t u d i e d i n 30 pat i e n t s w i t h acute myelogenous leukemia (AML), e i t h e r a f t e r exposure to 0 . 0 2 - 6 . 0 pg/ml daunomycin in v i t r o or a f t e r i n d u c t i o n t h e r a p y w i t h 6 - t h i o g u a n l n e , c y t o s i n e a r a b i n o s i d e and daunomycin. A great interindividual v a r i a t i o n of the maximum daunomycin c o n c e n t r a t i o n s in p e r i p h e r a l leukemic b l a s t s between 4.0 and 23.1 Ng/ml and in the a r e as under the curve d u r i n g the f i r s t two hours between 6.8 and 30.7 pg h/ml was found. There was no s t a t i s t i c a l l y significant c o r r e l a t i o n between in v i t r o and in v i v o p h a r m a c o k i n e t i c p a r a m e t e r s , nor cFT-6r-they ~ i v e l y correspond w i t h the outcome of TAD t h e r a p y . Thus, d i f f e r e n c e s in daunomycin s e n s i t i v i t y in v a r i o u s AMLs may be more critically i n f l u e n c e d by o t h e r f a c t o r s than cel ~ l u l a r tumor p h a r m a c o k i n e t i c s and m e t a b o l i s m of daunomycin in the c l i n i c . However, i t may be exp l o i t a b l e in p e r i p h e r a l leukemic b l a s t s f o r the intraindividual comparison of d i f f e r e n t t r e a t m e n t ~ules. (Supported by DFG: SFB 102.) Innere Universit6tsklinik und P o l i k l i n i k (Tumorf o r s c h u n g ) , Westdeutsches Tumorzentrum, HufelandstraBe 55, D-4300 Essen 1

OP 18.05

OP 18.07

A N T I T U M O R A C T I V I T Y OF ILMOFOSINE (BM 41.440) AND ITS A N A L O G S IN VITRO AND IN V I V O D.B.J. Herrmann, J.P. H~ick, W. Pahlke, E. Besenfelder, E. Bosies, P. Neubert, R. Endele, U. Bicker, and P.G. M u n d e r Ilmofosine ( 1 - h e x a d e c y l t h i o - 2 - m e t h o x y m e t h y l r a c - g l y c e r o - 3 - p h o s p h o c h o l i n e , BM 41.440) is a cytotoxic t h i o e t h e r p h o s p h o l i p i d analog w h i c h is c h e m i c a l l y related to the cell m e m b r a n e component ! y s o p h o s p h a t i d y l c h o l i n e . The objectives of this study were to e v a l u a t e the antineoplastic effect of this c o m p o u n d and of some derivatives on several tumor cell lines of murine and human origin in vitro and to determine their therapeutic a c t i v i t y in different in vivo m o d e l s ( m e t h y l c h o l a n t h r e n e - i n d u c e d fibrosarcoma, MethA; 3Lewis-lung carcinoma, 3LL). Furthermore, p h a r m a c o k i n e t i c s and organ distrib u t i o n of [14C] labelled Ilmofosine in M e t h A s a r c o m a - b e a r i n g m i c e were m o n i t o r e d 7, 14, 21 and 28 days after tumor cell inoculation. Ilmofosine and its analogs showed a time- and c o n c e n t r a t i o n - d e p e n d e n t inhibition of tumor cell growth in vitro with IC50 (50 % inhibitory conc e n t r a t i o n ) - v a l u e s a r o u n d 0.5-2 ~g/ml. There was also a dose- and t i m e - d e p e n d e n t antitumor/ a n t i m e t a s t a t i c activity in the M e t h A and 3LL in vivo systems, respectively. The investigations on p h a r m a c o k i n e t i c s and organ d i s t r i b u t i o n rev e a l e d a reversible, 30-50 fold a c c u m u l a t i o n of [14C] Ilmofosine in tumor, kidneys, liver and lungs c o m p a r e d to the plasma. These data will be d i s c u s s e d w i t h regard to b i o a v a i l a b i l i t y , e f f i c a c y and toxicity. I l m o f o s i n e has r e c e n t l y e n t e r e d clinical phase II trials in patients with refractory cancers. B o e h r i n g e r M a n n h e i m GmbH, Dept. I m m u n o p h a r m a c o logy, S a n d h o f e r Str. 116, D - 6 8 0 0 M a n n h e i m 31

IN VITRO TREATMENT OF NORMAL HUMAN BONE MARROW CELLS WITH DOXORUBICINE, CYTARABINE AND ETOPOSiDE. EVALUATION OF DRUG LONG TERM DAMAGE WITH LIQUID CULTURE AND CELL CYCLE ANALYSIS. M. Cavazzana. F. Calvo. P. de Cremoux. B. G6nv. C. Dresh. and G. Laaier The effects of doxorubicine (ADR) cytarabine (ARA-C), and etoposide (VP16) were studied on human bone marrow mononucleated cells using colony formation in agar, modified liquid culture system, and flow cytometry analysis of the cell cycle. Drug concentrations tested during a 1-h incubation ranged from 0.1 to 4 ~g/ml for ADR, from 0.3 to 30 ~g/ml for VP16 and from 10-2 to 10-6 M for ARA-C. Regression analysis of the dose-response curves was used to assess the drug concentration that inhibited 90 % + 5 % (LD90) of colony growth. LD90s were 0.4 i~g/ml for ADR, 20 ~g/ml for VP16, and 10-4M for ARA-C. LD90surviving celts were cultured in liquid medium for 3 weeks. Surviving ceils over this time were 13 % of the control for ADR, 22 % for VP16 and 96 % for ARA-C. Although cells decreased drastically in ADR- and VP16-treated samples, granulocyte-macrophage colony-forming units (CFU:GM) per 105 surviving cells rose to twice the control for ADR, to 60 % for VP16 and to 150 % for ARA-C. Flow cytometry analysis of the cell cycle was performed at day 0 and at day 4 after treatment with the LD90 dose. It showed a rapid and reversible effect of ARA-C on cells in the S-phase, whereas the action of VP16 concerned all cells, regardless of their cycle phase. We conclude that the direct effects of the three drugs on CFU-GM are poorly predictive of hematopoietic reconstitution capacity, except for VP16. Liquid culture gives a much more accurate appraisal of the long term damage and recovery due to anticancer drugs.

Pharmacology Laboratory and tNSERM U204, HSpital Saint Louis, 75010 PARIS, FRANCE

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PHABMACOKINETIC AND pBARMACODYNAMIC STUDIES WITH 4'-EPIDOXORUBICIN IN NASOPKARYNGEAL C A R C I N O M A oliver Y-P Hu | , S-P chang 1,2 , J-M Jame 2, K-Y Chen 2

INTERAND INTRA-INDIVIDUAL VARIABILITY IN N I F E D I P I N E PHARMACOKINETICS AND EFFECTS P.A. Soons, J . H . M Schellens, A . F C o h e n and D.D. B r e i m e r

The plasma pharmaeokinetic profile of 4'-epi-doxorubiein was investigated in 27 patients with nasopharyngeal earcinoma(NPC) after single Iv rapid infusion. All patients had normal liver and renal functions, plasma concentrations of the parent componnd were specifically determined by a high performance liquid chromatography method with UV detection at 254 nm. Three compartment open model ~as fitted to plasma levels of the compound, triexponential decrease of plasma concentrations with long terminal plasma half-life (44.8+/-21.2 hrs) were observed in 27 patients. The respective mean+/-sd of ser~mzeoncentration at 72hrs, area under the concentration-time curve, plasma clearance and terminal elimination rate constant for complete response patients were 7.67+/-1.98 ng/mi, 4002+/-3080 ng*h/ml, 26.6+/-12.9 i/h*m 2 and 0.009+}-0.007 hr -I , compared to non-responders 4.96+/-1.8 ng/mi, 1881+/-652.8 ng*h/mi, ~ ~...iI~ i i ~ 2 and 0.017+/-0.006 hr -I sbc~:ed ei~n~ficant difference (P<0.05). Epirubicin produced 52% response rate, 6 patients with complete response, 8 were partial responders, ii with no change and 2 were progressive disease. There was no relationship could be found among pharmaeokinetio parameters and leukopenia. There were no correlation among other pharmacokinetic parameters, such as age and sex. These observations strongly snggested that plas~%a clearance may be one of the determining factors affected the 4'-epi-doxorubiein respond or non-respond to NPC patients, and dosage adjustment according to plasma clearance would probably increase the response rate. l.School of Pharmacy, National Defense Medical Center, Taipei, Taiwan, Republic of china 2.Cancer Therapy Center, Veterans General Hospital, Taipei, Taiwan, Republic of china

Wide interlindividual variability in the kinetics of nifedipine (NF) has been reported, which relates to firstpass oxidation of NF to its pyridine metabolite (M-0). Inter-individual variability in NF kinetics was studied in 130 young healthy subjects after administration of a "cocktail" of 20 mg NF (retard tablet), 50 mg sparteine and i00 mg phenytoin-sodium. Mutual interactions of probe drugs were excluded in 8 healthy subjects. The AUC of NF (median 279 ng.h/ml; range 105-i010) varied 10-fold, and that of M-0 varied 17-fold (median 153 ng.h/ml; range 51887). The distributions of AUC of NF and of M-0 were both highly skewed, hut no clear bimodality was observed. The AUG ratio NF/M-0 showed to be of no value to characterize rate of oxidation since it was only slightly correlated with AUC NF (r2=0.08). 0-8 h excretion of the major metabolite (pyridine monomethylester) was very low correlated to AUC of NF (rg=0.001) and its distribution was not different from a symmetrical normal distribution (mean • SD 26.2 i 7.0 % of dose;p=0.6) Intra-individual variability in NF kinetics and effects were studied in 12 healthy subjects on three occasions with six days wash-0ut periods in between, using single doses of i0 mg NF (capsules). In order to cover a wide range of AUC values, subjects were selected from previous studies. Mean AUC of NF varied 4.7-fold (range 92-433 ng.h/ml) between subjects. Within-subject coeficient of variation (CV~) for AUC of NF and M-0 and of their ratio were 13Z, 17% and 22% respectively. Maximum effect (Emax) and Area Under Effect-time curve (AUE) for systolic (SBP) and diastolic blood pressure (DBP) and heart rate (HR) were all small and very variable. CV~ ranged from 34 Z (Emax-HR) to 290 % (AUE-SBP). The 10-fold inter-individual variability in kinetics of NF is very large as compared to the short-term intraindividual variability (CV~ 13Z). Division of Pharmacology, Center for Bio-Pharmaceutical Sciences, P.O. Box 9503, 2300 RA Leiden, The Netherlands

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EVIDENCE FOR A DISSOCIATION IN THE CONTROL OF SPARTEINE AND METOPROLOL METABOLISM IN NIGERiANS. M.S. Lennard, A.O. lyun, G.T. Tucker and H.F. Woods. In a previous study we could find no evidence that the metabolism of metoprolol (M) and debrisoquine is polymorphic in Nigerians. As an extension to this work, the pattern of oxidation of metoprolol has been compared to that of sparteine (S) in an unrelated Nigerian population. Methods: Subjects were given i00 mg of M (n = 141) and I00 mg of S (n = 88) p.o. in random order and at least one week apart. Urine was collected for the following 8h and assayed for M, S and their metabolites. Results: The was a relatively weak correlation (r s = 0.51, p < 0.001; n = 82) between the metoprolol/~-hydroxymetoprolol (M/HM) and the sparteine/dehydrosparteines (S/DHS) ratios. Inspection of the log I S/DHS ratio distribution suggested the presence of two p~enotypie groups. 4 (3.8%) of the subjects excreted negligible amounts of DHS and had estimated 8/DHS ratios of 72, 203, 504 and 1400. In contrast, there was no evidence of bimodality in the distribution of the log I M/HM ratios. The M/HM ratios of the putative poor meta~olisers of S were 17.1, 0.03, 0.51 and 0.75, values which were not significantly different from those of the remainder of the population. The med~ian S/DHS value (1.91) was three times higher than that reported by Woolhouse et al (Clin. Pharmac. Ther. 37 (1985) 512) in Ghanaians. The median M/HM ratio (0.61) was significantly lower than those obtained from a previous study in Nigerians (1.06, p < 0.001) and in Caucasians (0.79, p = 0.048). Conclusion: These data provide some evidence for a dissociation in the control of sparteine and metoprolol metabolism in Nigerians. University Department of Pharmacology and Therapeutics, Royal Hallamshire Hospital, Sheffield SI0 2JF, U.K. and Department of Medicine, University College Hospital, Ibadan, Nigeria.

PROPAFENONEKINETI~S IN PATIENTS WITH COY~LEX V E N T R I C U L A R A R R H Y T ~ d l A S A N D C A R D I A C DISEASE R.Latini~ P.Colombo, F.Gaita, P.Giani~ M.Landolina~ D.Leopaldi~ A.Vincenti and the ADEG grot~ The d o s e a n d t h e o x i d a t o r p h e n o t y p e a r e t w o m a j o r determinants of p r o p a f e n o n e ( P ) m e t a b o l i e degradation.Two active metabolites,5-OH-P and N-depropyl - P ( N D P P ) e a n b e f o u n d in p l a s m a of p t s . W e m e a s u r e d P , 5 - O H - P a n d in 7 p t s a l s o N D P P in t r o u g h p l a s m a sample~mean 3/pt~range l-8)drawn from 58 pts a n d i n 1 1 / 5 8 we a l s o s t u d i e d drug washout. All pts received P a t 150 o r 3 0 0 m g / 8 h f o r 3 2 7 5 3 8 ( S E M ) d a y s " (2-986)in the course of a multicentre randomized

triaI(ADEG).P trough concentration/dose(P/D,ng/ml /mg)significantly increased from .4~.05 to .73~.07 by doubling the dose.Mean 5-OH-P/P plasma ratio w a s . 6 9 ( . 8 2 at l o w a n d .53 at h i g h L i o n t l / 2 of P w a s l l . l •

dose).Elimina5-OH-P/P

.2 i d e n t i f i e d 4 / 5 8 as s l o w m e t a b o l i z e r s ( S M ) , who also had a P/D 1(mean for the population .55~.05). W a s h o u t t l / 2 in 2/4 SM w e r e 8.3 a n d 13.9h. C o n c e n t r a t i o n s of N D P P w e r e s i m i l a r to t h o s e of 5 - O H - P in e x t e n s i v e m e t a b o l i z e r s ( 1 9 9 • 228• a p o p u l a t i o n of a r r h y t h m i e pts with cardiac disease P t l / 2 c a n b e p r o l o n g e d b y o t h e r f a c t o r s t h a n genetics(left ventrieular failure, liver disease). SM pts c a n n o t be i d e n t i f i e d s i m N l y b y p r o l o n g e d P t]/2~but by finding undetectable 5 - O H - P in p l a s m a , i n p r e s e n c e of g e n e r a l l y h i g h P a n d n o r m a l NDPP.Metabolism to N D P P d o e s n o t s e e m to be a f f e c ted by oxidator phenotype. Istituto "M.Negri",Via Eritrea 62,20157MILANO Italy.

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D I A Z E P A M M E T A B O L I S M A N D ITS A S S O C I A T I O N W I T H POLYMORPHIC S-MEPHENYTOIN HYDROXYLATION L. B e r t i l s s o n , T.A. B a i l l i e and J. R e v i r i e g o In a r e c e n t s t u d y (Clin. P h a r m a c o l . Ther., in p r e s s 1989), w e g a v e s i n g l e o r a l i0 m g d o s e s of b o t h d i a z e p a m and d e m e t h y l d i a z e p a m to 16 h e a l t h y s u b j e c t s s e l e c t e d to i n c l u d e p o o r h y d r o x y l a t o r s o f b o t h d e b r i s o q u i n e (n=4) and S - m e p h e n y t o i n (n=3). In p o o r h y d r o x y l a t o r s of S - m e p h e n y t o i n , the p l a s m a c l e r a r a n c e of b o t h b e n z o d i a z e p i n e s w a s less t h a n h a l f the v a l u e s f o u n d in e x t e n s i v e h y d r o x y l a t o r s of S - m e p h e n y t o i n (p<0.001). In c o n t r a s t , the k i n e t i c s of the two b e n z o d i a z e p i n e s w e r e e s s e n t i a l l y the same in e x t e n s i v e and p o o r h y d r o x y l a t o r s of d e b r i s o q u i n e . The m e t a b o l i s m o f b o t h d i a z e p a m (c_aa. 62% of w h i c h is d e m e t h y l a t e d in vivo) and d e m e t h y l d i a z e p a m (which is m a i n l y h y d r o x y l a t e d to oxazepam) is thus a s s o c i a t e d w i t h the p o l y m o r p h i c S-mephenyfioin, b u t not w i t h the debrisoquine, hydroxylation. In h u m a n l i v e r m i c r o s o m e s , the d e m e t h y l a t i o n of d i a z e p a m f o l l o w e d M i c h a e l i s - M e n t e n k i n e t i c s c o n s i s t e n t w i t h the i n v o l v e m e n t o f a s i n g l e enzyme. H o w e v e r , in the 4 livers i n v e s t i g a t e d to date, the h y d r o x y l a t i o n o f d i a z e p a m w a s c a t a l y z e d b y m o r e than one enzyme. A t l o w s u b s t r a t e c o n c e n t r a t i o n s , c o r r e s p o n d i n g to t h e r a p e u t i c c o n c e n t r a t i o n s (1-2 ~M), the r a t e of d e m e t h y l a t i o n was h i g h e r t h a n or the same as that of h y d r o x y l a t i o n . H o w e v e r , at h i g h c o n c e n t r a t i o n s o f d i a z e p a m (250 pM), the r a t e of h y d r o x y l a t i o n w a s h i g h e r t h a n t h a t of demethylation. Preliminary results show that m e p h e n y t o i n m i g h t be a w e a k i n h i b i t o r of d i a z e p a m d e m e t h y l a t i o n , b u t a p p a r e n t l y d o e s not i n h i b i t the h y d r o x y l a t i o n r e a c t i o n . D e p a r t m e n t of C l i n i c a l P h a r m a c o l o g y at the Karolinska Institute, Huddinge Hospital, S-14186 Huddinge, Sweden

VALIDATION OF THE TOLBUTAMIDEMETABOLIC RATIO FOR POPULATION SCREENINGUSING SULPHAPHENAZOLE TO PRODUCE PHENOTYPIC SLOWMETABOLIZERS D.J. Birkett, J.O. Miners and M. Veronese Tolbutamide (T) is metabolized by methylhydroxylation which accounts for greater than 90% of total CL in man. Only a very small proportion of the dose is excreted unchanged making analysis of urinary T d i f f i c u l t . The existence of polymorphic regulation of T hydroxylation has been controversial as previous studies have involved formal measurements of CL or h a l f - l i f e in relatively small numbers of subjects. A method has been developed to measure T and hydroxytolbutamide (OHT] in urine. Six subjects were given single doses of T 300 mg with and without sulphaphenazole (SZ) 500 mg 12 hourly. PlasmaT CL and h a l f - l i f e were measured, as were the metabolic ratios (OHT/T) in successive 6 hourly urine collections. The mean T CL decreased from 0.20• ml/min/kg without SZ to 0.04+0.01 ml/min/kg with SZ and mean h a l f - l i f e increased from 7.3+0.9 hr to 38.8+13.3 hr. The mean metabolic ratio in-the 6 to 12 hr-urine decreased from 794+87 to 126+79. Therewas a good correlation between CL and metabolic ratio (r = 0.94, n = 12, p
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D-PROPOXYPHENE IS A POTENT INHIBITOR DEBRISOQUINE HYDROXYL~TION EJ~ Sanz, E. Dnmont and L. Bertilsson

OF

Debrisoquine (10 rag) and racemic raephenytoin (100 rag) were given orally at 11 pra to 14 healthy subjects and urine was collected for 8 hrs. The metabolic ratio (MR) ofdebdsoquine veried between 0. l and 8.3 and the S/R ratio of mephenytoin varied between 0.05 and 0.44. This shows that all were extensive raetabolizers of both drugs. After at least 4 weeks the same subjects received a 150 mg tablet of d-propoxyphane (Dolotard| A/S Alfred Benzon) at 6 pra. The same evening at 11 pra. the debdsoquine-raephenytoin test was repeated. This single dose of d-propoxyphene caused no change in the raephenytoin S/R ratio, but increased the debfisoquine MR in each

subject (Mann-Whitney U=49; p< 0.025). The 4 subjects with an MR >4 (5.1-8.3) in the first test had a MR of debdsoquine in the second test ranging between 22 and 40, falsely classifying them as poor metabolizers of debfisoquine. In vivo d-propoxyphene seems to be an inhibitor o f debdsoquine, but not of s-mephenytoin, hydroxylase. In human liver microsomes d-propoxyphene inhibited the 2hydroxylation of desipramine competitively with Ki=3.7 uM. Desipraraine and debrisoquine hydrox-ylations are closely associated. These in vlvo and .in vitro experiraents show that d-propoxyphene is a potent inhibitor of debrisoquine hydroxylase.

Dept. of Clinical Pharmacology,Karolinska Institute, Huddinge Hospital, S-141 86 Huddinge, Sweden and Dept. of Pharmacology, University of La Laguna, P.O. Box 55, La Cuesta, Tenerife, Spain.

A CHANGE IN BIOTRANSFORMATION PHASE II FROM GLUCURONIDE CONJUGATION TO SULPHATIDE CONJUGATION AS A TOXICOLOGICAL SIGN G. Wieckhorst, R. Latza, C. Szypula, U. TheiS, J. Ulmer and P.W. LNcker In a long period study a chloride containing substance was tested in a group of volunteers. At the beginning, during and after the study we determined the amount of glucuronized and sulphatized conjugates with eortisol as an endogenous marker. In the literature and in our own study there is a predominance of individuals exhibiting glueuronide conjugation as the main pathway of metabolism. Towards the end of the study there was a marked change in favour of sulphatide conjugation. The method of blood and urine analysis used in this test and its standardization will be described. Further substances like alcohol are tested for their potential to provoke the same reaction. In addition the following questions will be discussed: i) Does a change in metabolism indicate a toxic effect of the administered drug? 2) Is there a potential risk for people with a high rate of sulphatide conjugation for pharmaeokinetie reasons? Institut f~r klinische Pharmakologie Bobenheim, Richard-Wagner-Str. 20, D-6718 Gr~nstadt

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SULPHOXIDATION OF CARBOCYSTEIN: METHODS FOR ANALYSIS OF PHARMACOKINETICSAND ITS GENETICS J. BrockmSller, B. Staffeldt, Z.J. Simane* and I. Roots sulphoxidation of carbocystein (CMC) has been shown to be a genetically polymorphic enzymatic process. A low degree of sulphoxidation seems to be associated with primaz~biliary cirrhosis, increased D-penicillam/lle toxicity and possibly further deseases. Analytical method in these studies was paper chrcmatography.

EFFECTS OF ENOXIMONE ON EXERCISE TOLERANCE IN HEART FAILURE PATIENTS: A PLACEBO CONTROLLED, DOUBLE-BLIND EVALUATION USING ANAEROBIC THRESHOLD. H. ITOH, A. Eoike, M. Doi, S. Nakamura, K. Taniguchi, F. Marumo~ and A. Sakuma The effect of single oral doses of new phosphodiesterase inhibitor, enoximone (ENOX), on anaerobic threshold (AT) was investigated in 33 heart failure patients (NYIIA Class II:32~ Ill:l) using gas exchange parameters during ergometer exercise testing. After baseline AT was determined, they were randomised to receive placebo, 25mg O r lOOmg ENOX. The serum concentrations (ng/ml) of ENOX and its active metabolite MDL-19438 were determined three hours after dosing when the second exercise testing was performed. There were five non drug-related drop-outs. Overall "Improvement" was judged by the attending doctor. (mean• *: P<0.01 t-test) Rx (n) AT(VOz: ml/min/kg) Improv. Enox/19438(ng/ml) P (9) 15.0• ~ 15.1• 33.3% 25 (9) 13.0• ~ 13.9• 55.6% 46•177 i00 (10) 14.4• ~ 16.2• 80.0% 262•177 AT was improved significantly in only the 10Omg group. The rate of "improvement" as judged by the attending doctor was dose-dependent. These results suggest that 100mg of ENOX improves exercise tolerance acutely. The results of chronic dosing with lower doses are awaited. Second Department of Internal Medicine, Tokyo Medical and Dental University, 5-45 Yushima l-chome, Bunkyo-ku, Tokyo 113, Japan

We have developed HPLC-methods, which allow quantitation of CMC, C94C-sulphoxides, the decarboxylated derivative S-methylcysteine (MC), end MC-sulphoxides. Precolinnnderivatization procedures using dimethylaminoazobenzene sulfonyl chloride and (9-Fluorenylmethyl)-chlorformiat (FMOC) were adopted for analysis of CMC-derivatives. Calibration curves wlthblank urine and serum samples showed regression coefficients > 0.998 in the range from 0.2 to 600 zg/ml. Thus, also serum kinetics of CMC-sulphexides couldbe analysed (previously described only by use of radiolabeledCMC). Furthermore, the R- and S-isomers of the sulphoxides were well separated, which allows analysis of chiralityof sulphoxidationinhtnnans. The FMOC-method is suitable for screezling of larger collectives using an automatized HPLC-procedure. We describe sulphoxidationbythe quotient CMC-sulphoxides/CMC-sulphoxides+CMC of urine collected for 8 hours after oral ingestion of i.i g CMC. This value varied between 3 and ii in a preliminary reference collective of healthy human volunteers (n=20), measured by the HPLC method. The measured extent of sulphoxidation is significantly lower than describedbefore (S.C. Mitchell et al., Br. J. clin. Pharmacol. 18, 507-521, 1984), therefore influences, which might affect sulphoxidaticn, such as dose dependency, are now being studied. Institut for Klinische Pharmakologie, Klinikum Steglitz der Freien Universit6t Berlin, Hindenburgdanm 30, D-1000 Berlin 45; *E. Merck AG, Darmstadt, FRG

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ORAL ENOXIMINE IN CONGESTIVE HEART FAILURE: SHORT-TERM EFFECTS AT REST AND DURING EXERCISE ON HEMODYNAMICS, ANAEROBIC THRESHOLD AND AHRHYTNMIAS W. Zwehl, R. Huber, V. Klauss~ H. Mudra, A. Vogler, R. Schmidt , H. Dieterich, M. Scheininger, K. Theisen Oral enoximone, a phosphodiesterase inhibitor with both positive inotropic and vasodilator properties, was given to 8 patients (44-64 years) with congestive heart failure at doses of 300 mg/die. Cardiac index (CI), stroke volume index (SVI) and pulmonary wedge pressure (PCW) were assessed by right heart catheterisation at rest and during exercise, using a modified Naughton protocol. Simultanously VOz and VCO2 were measured to determine anaerobic threshold (AT).In addition exercise radionuclide ejection fraction (EF) and 24-hour Holier monitoring were performed. Calculated were mean arterial pressure (MAP), stroke work index (SWI), systemic (TPR) and pulmonary arterial (PAR) resistance. All parameters were measured on entry to the study (Ctr.) and after 8 days of treatment (Enoxi.): (mean, *=p<0.05) Rest Exercise Ctr Enoxi Ctr Enoxi EF (%) 22 27* 21 31" PCW (mmHg) 17.0 11.5" 28.7 23.2* CI (i/min/m 2) 2.4 2.8* 4.1 4.8* SVI (ml/min/m 2) 30.2 37.7* 35.0 41.2" MAP (mmHg) 98.0 103.0 112.3 112.5 SWI (g*m/m~) 35.5 46.2* 41.5 49.5 TPR (dyn*sec 1666 1470" 1162 959* PAR cms ) 377 273* 440 309* AT (VOzml/min/kg) 14.0 16.6" Proarrhythmic effects were seen in 6 pts. (increase in VPB's, Couplets and VT's), 2 pts. required additional antiarrhythmic treatment. In conclusion, short-term application of oral enoximone results in improved cardiac pump function and anaerobic threshold with lowering of vascular resistance in pts. with congestive heart failure. A slight proarrhythmic effect was seen. Med. Klinik Innenstadt der Universit~t H~nchen, Ziemssenstr. I, 8000 M~nchen 2, FRG

A C U T E E F F E C T S OF E N O X I M O N E A N D C A P T O P R I L I.V. ON H E M O D Y N A M I C S IN P A T I E N T S W I T H C H R O N I C H E A R T FAILURE M.Scholz, G.D.Kneissl, W.-D.BuBmann, M.Kaltenbach The a c u t e e f f e c t s of E n o x i m o n e (E) and C a p t o p r i l (C) w e r e c o m p a r e d in a single blind, randomised, c r o s s - o v e r trial in i0 P a t i e n t s (P) -9x d i l a t i v e c a r d i o m y o p a t h y , ix c o r o n a r y h e a r t d e s e a s e - w i t h h e a r t f a i l u r e (NYHA III:6P, IV:4P). C a r d i a c i n d e x (CI,i/min*mA2), m e a n p u l m o n a r y a r t e r y p r e s s u r e (PAM,mmHg) and p u l m o n a r y c a p i l l a r y w e d g e p r e s s u r e (PC,mmHg) w e r e m e a s u r e d at b a s e l i n e and 1 5 , 30 and 60 m i n after 0 , 1 m g / k g C and 0 , 7 5 m g / k g E r e s p e c t i v e l y f o l l o w e d b y m e a s u r e m e n t s 15, 30, 60, 180 and 3 0 0 m i n a f t e r 0 , 2 m g / k g C and 1 , 5 m g / k g E respectively. Results: CI w a s u n c h a n g e d 6 0 m i n after 0 , 1 m g / k g C, i n c r e a s e d 6 0 m i n after 0 ~ 2 m g / k g C b y 7,7% from 2 , 1 + - 0 , 5 to 2 , 4 + - 0 , 5 (p=0,001) and w a s u n c h a n g e d after 5h. CI i n c r e a s e d 60min after 0 , 7 5 m g / k g E b y 32,5% from 2 , 1 + - 0 , 5 to 2 , 9 + - 0 , 4 (p~0,001), 60min after 1 , 5 m g / k g E b y 59~o to 3,3~-0,6 (p=0,001) and after 5h b y 19% to 2 , 5 + - 0 , 4 (p~0,01). P A M w a s u n c h a n g e d 60min a f t e r 0 , 1 m g / k g C, d e c r e a s e d 6 0 m i n after 0 , 2 m g / k g C b y 10% from 35,7+-11 to 31,7+-10 and was u n c h a n g e d a f t e r 5h. P A M d e c r e a s e d 60 m i n after 0 , 7 5 m g / k g E b y 13% f r o m 35+-9 to 31+-10 (p=0,01), 6 0 m i n after 1,5mg/ kg E b y 19% from 35+-9 to 27+-9 (p ~ 0,001) and w a s u n c h a n g e d after 5h.PC d e c r e a s e d 6 0 m i n after 0 , 1 m g / k g C b y 23% from 24+-8 to 19+-9 (p~0,05) and w a s u n c h a n g e d 6omin und 5h after 0 , 2 m g / k g C. PC d e c r e a s e d 6 0 m i n after 0 , 7 5 m g / k g E b y 35% from 25+-6 to 17+-8 (pa0,01) and 6 0 m i n after 1 , 5 m g / k g E b y 47% to 14+-8 ( p = 0 , 0 0 1 ) a n d w a s u n c h a n g e d after 5h. Conclusion: T h e c l i n i c a l t r i a l s h o w e d that in P w i t h c h r o n i c h e a r t f a i l u r e (NYHA I I I + IV) the acute i n c r e a s e of CI and d e c r e a s e of PC is h i g h e r after E than a f t e r C. The i m p r o v e m e n t of h e m o d y n a m i c s lasts longer after i.v. E t h a n i . v . C . Z e n t r u m der I n n e r e n M e d i z i n der U n i v e r s i t ~ t s klinik Frankfurt, Th-Stern-Kai, D-6000 Frankfurt

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A D D I T I O N O F X A M O T E R O L T O C A P T O P R I L IN S E V E R E CHRONIC HEART FAILURE

THE EFFECT OF XAMOTEROL ON ARRHYTHMIAS IN PATIENTS WITH MILD TO MODERATE HEART FAILURE

H M McAlpine,

S J. S Vi.rk., N H Anfilogoff, N Laws.on, Fengxia Qi.ang, R G. MurFay.,'W.A Littler, M K Davies

E Henderson,

H J Dargie

X a m o t e r o l (X), a ~ l - p a r t i a l a g o n i s t , h a s b e e n a d v o c a t e d in p a t i e n t s w i t h mild to moderate c h r o n i c h e a r t f a i l u r e (CHF). H o w e v e r , its ~ blocking activity might impair cardiac f u n c t i o n i n s e v e r e CHF. Therefore we did a double-blind, crossover study of X and p l a c e b o , e a c h for 6 weeks, in 15 p a t i e n t s w i t h s e v e r e C H F (mean L V f r a c t i o n a l s h o r t e n i n g 19%) o n o p t i m a l s t a b l e d o s e s o f frusemide and captopril. X increased resting s y s t o l i c b l o o d p r e s s u r e (SBP) (122 • 5 vs. 113 • 6 mmHg, p < 0 . 0 5 ; m e a n • SEM) a n d r e d u c e d d o u b l e - p r o d u c t (heart r a t e x SBP/10O) d u r i n g m a x i m a l t r e a d m i l l e x e r c i s e (147 • 9 vs. 174 • Ii, p = 0 . 0 0 2 ) . E x e r c i s e d u r a t i o n on X w a s i m p r o v e d o r u n c h a n g e d in Ii p a t i e n t s a n d r e d u c e d in 4. Maximal oxygen consumption was unchanged but respiratory exchange ratio was l o w e r at e q u i v a l e n t s u b m a x i m a l w o r k l o a d s on X (0.95 • 0.02 vs. 1.03 • 0.03, p<0.05) suggesting improved tissue perfusion. There w e r e n o a d v e r s e events. Thus, in p a t i e n t w i t h s e v e r e C H F on c a p t o p r i l , X m a y f u r t h e r improve cardiac function and limit resting hypotension. D e p a r t m e n t of C a r d i o l o g y , G l a s g o w , GII 6NT, UK.

Western Infirmary,

A major side effect of the use of oral inotropes in chronic heart failure (CHF) is their propensity to exacerbate cardiac arrhythmias. Xamoterol is a novel B~-partial agonist with 43% of the intrinsic sympathomimetic activity of the full agonist isoprenaline and used in the treatment of mild to moderate heart failure. In a randomised double-blind placebo controlled cross-over study of Xamoterol, 26 patients with mild to moderate heart failure secondary to ischaemic heart disease (21)'or congestive cardiomyopathy (5), had 24 hour ambulatory monitoring prior to and at the end of 13 week treatment periods. During treatment with Xamoterol there was no significant change in mean hourly ventricular extrasystoles (VE's) as compared with baseline or placebo (baseline 56 + 42 VE's/hr, placebo 18 + 7 and Xamoterol 30 + 17). ~he number of patients sh~wing complex forms (multiform VE's, pairs, ventricular tachycardia (VT)) was similar in the three groups (baseline 19/26, placebo 19/26 and Xamoterol 20/26), as was the number of patients exhibiting VT alone (baseline 4/26, placebo 6/26 and Xamoterol 5/26), Treatment with Xamoterol, therefore, may allow provision of inotropic support in mild to moderate CHF without exacerbation of cardiac 'arrhythmias. Department of Cardiology, University of Birmingham, Birmingham, U.K.

OP 20.05 EVALUATIONOF BETA-ADREHERGICPAgTIALAGONISTPROPEHTIE5 OF XkJIOTEROLIN HE/dT FAILUREPATIENTS, Ph. hechat, H. Richaudf H. Koea~da. P. Fournier, Y. Grosp[eat.

Partial betaadrenoceptor agonists drugs such as xa=oterol are currently evaluated in heart failure tflD. Combinationof their etimulatory properties at rest on contractility with inhibition of the deleterious effects of high plasmatic catechola~ines levels on physical exercises could provide functionnal and prognostic improvement in these patients, We non invaeively studied xaeoterol hesodyna=ic effects and the xamoteroldobutaaine interaction in Ig HF patients with heart failure eith a dilated cardioeyopathy in sinus rhythe: 13 sen , 3 women, Bean age 43~13 years, in Hew

York Heart Association functionnal class 111 or IV. Accordingto a double blind randomizedcross-over protocols, xamotero] i0.15 mg/kg iv) or placebo sere adainistrated 30 minutes before infusionof a progressively increasing rate of i.v infused dobutaaine (~, 6, 9, and t2 ecg/kg/ain). Each dose was

infused during a 20 sin period. Left ventricular function and cardiac output were evaluated with an echodoppler Kontrun Signs. In these patients mean plassa norepinephrine level at rest was 443.133 pgt=l,

and during a bicycle stress test, piasaa norepinsphrlne concentrations increased to 1768~687pusl correspondingto a high syapathetic tone. Beta l sensitivity was particularly lee, since dobutaaine effects were only significant above the infusion rate of 3 acg/kg. Xamoterol per se did not induce significant changes in heart rate, blood pressure, double product {Heart rate * systolic blood pressure) or cardiac output. In one patient however, a transient decrease in blue d pressure occured without tachycardia. Xanoterel significantly reduced dobutasine effects on heart rate, blood pressvre and cardiac output. We conclude that in patients with severe heart f a i i v r e and high norepinephrine levels, xaeoteroI (O. i5ag/kg) in nest cases does not induce any deleterious hemodynamiceffect, appears nell tolerated and inhibits beta 1 adrenergic alleviation.

adrenerr

I~partesent de pharzauologie ciinique eL Service de card•177 CHU Piti~Salp~tri~re,Paris,France, 75013

OP 20.07 XAMOTEROL IN ACUTE MYOCARDIAL INFARCTION: EFFECT ON HAEMODYNAMICS, ARRHYTHMIAS, NEUROENDOCRINE RESPONSES & CLINICAL OUTCOME J McMurray, C Lang, D Madean, AD Struthers & DG McDevitt. Xamoterol iX) is a new partial beta-1 adrenoceptor agonist which reduces myocardial ischaemia, improves left 9ventricular function and increases exercise tolerance in fpatients with chronic heart failure. Many patients with heart allure (HF) are at risk of myocardial infarction (MI) and MI may be complicated by HF. We have therefore investigated the effects of X in acute MI. 51 consecutive patients with acute MI (35m, 16f; mean age 58.7 yr.), including 17 with HF, were entered into a randomised double blind comparison of X and placebo (P). Treatment was started on day three of admission and continued for seven days. One patient died prior to random•177 Three patients were withdrawn- one with ventricular fibrillation iX), one with ventricular tachycardia (P) and one with atrioventricular block iX). Overall X increased mean heart rate for the period 0000h0600h- X 79+2; P 72_+2 (p<0.03). Compared to P, X had no effect on blood pressure, double product or the incidence of ventricular tachycardia. Reduction in ventricniar premature beats over the seven day treatment period was- X 69_+ 11%; P 59+20% (p=n.s.). Active treatment did not affect catechotamine or ANF levels post-MI though plasma renin levels tended to be lower in the X sroup. Three X and seven P patients, required new antiangmal therapy and one P panent developed new HF.These results suggest that X can be administered safely to patients with MI, including those with HF. Department of Clinical Pharmacology, Ninewells Hospital and Medical School, Dundee DD1 9SY, Scotland, U.K.

A 72

OP 20.08

OP 21.02

CICLOPROLOL, A ~I PARTIAL AGONIST, ENHANCES DIGOXIN INOTROPIC ACTION IN HEALTHY VOLUNTEERS. B. Carcone, S. Weber, P. Rosenzweig, G. Bianehetti, D. De Lautnre, M. Letrait, A. Ven0tj G. Strauch. Cicloprolol, is a ~i partial agonist considered for the treatment of coronary artery disease (CAD) with impaired left ventricular function (LVF), a clinical condition in which the use of Digoxin is rather frequent. Thus interaction between oral Digoxin 0.25 mg/day and Cicloprol01 50 mg/day was studied in i0 healthy volunteers following a double blind cross-over design during a 3 weeks period. Digoxin was given alone the first week to reach steady state, then associated to Cicloprolol or placebo during weeks 2 and 3. Digoxin kinetics, at the end of each period, remained unchanged wether Digoxin was associated to placebo (Cmax : 1.7 • 0.2 ng.ml -I, AUC : 12.8 • 1.8 mg.ml-l.h) or Cicloprolol (Cmax 1.7 • 0.i ng.ml -I, AUG : 11.3 • 1.3 ng.ml-l.h.NS). LVF assessed by echocardiography was enhanced by Cieloprolol (shortening fraction 37 • 3 % versus 32 • 3 %, p < 0.05, ejection fraction 66 • 4 % versus 61 • 5 %, p < 0.05). We conclude that Cicloprolol does not alter Digoxin kinetics and enhances its inotropie effects. These results warrants further study in patients. Synthelabo Recherche (LERS), Dept. of Clinical Research, 58 rue de la Glaci~re 75013 PARIS FRANCE.

CLINICAL PHARMACOKINETICS AND PHARMACODYNAMICS OF METHYLPREDNISOLONE PHOSPHATE H. Derendorf, H. M 6 1 1 m a n n , P. R o h d e w a l d , C. M 6 1 1 m a n n , M. Krieq, S. T u n n , J. B a r t h a n d H.J. R6thig The pharmacokinetics and pharmacodynamics of intravenously administered methylprednisolone p h o s p h a t e w e r e i n v e s t i g a t e d at s e v e n d i f f e r e n t dose levels from 16 t o i000 m g in h e a l t h y volunteers. Linear pharmacokinetics were o b s e r v e d for b o t h m e t h y l p r e d n i s o l o n e phosphate and methylprednisolone. Forty different p h a r m a c o d y n a m i c p a r a m e t e r s w e r e f o l l o w e d in t h e s a m e s u b j e c t s as a f u n c t i o n of t i m e for one week. S i g n i f i c a n t d o s e d e p e n d e n t p h a r m a c o d y n a m i c p a r a m e t e r s w e r e t h e p l a s m a l e v e l s of g l u c o s e , sodium, t r i g l y c e r i d e s a n d c o r t i s o l as w e l l as the number of lymphocytes, segmented cells, m o n o c y t e s , e o s i n o p h i l s a n d s t a b cells. For m o s t of these parameters maximum effects were observed between 12 a n d 24 h o u r s a f t e r d r u g administration. An integrated pharmacokineticpharmacodynamic model was developed that allowed translation of the methylprednisolone plasma concentration-time-profiles into effect-timeprofiles. The model allowed excellent p r e d i c t i o n s o f t h e p h a r m a c o d y n a m i c e f f e c t s as a f u n c t i o n of t i m e for a n y d o s e in t h e r a n g e s t u d i e d at a n y t i m e point. F u r t h e r m o r e , it c o u l d b e s h o w n t h a t t h e c u m u l a t i v e e f f e c t s in f o r m of the areas under the effect-time-curves were d i r e c t l y p r o p o r t i o n a l t o t h e l o g a r i t h m of t h e dose. T h e i n c r e a s e in c u m u l a t i v e e f f e c t w i t h increasing dose was mainly caused by prolonged a c t i v i t y , b u t n o t b y f u r t h e r i n c r e a s e of m a x i m u m effects which were already observed with the l o w e r d o s e s studied. College of Pharmacy, University of Florida, G a i n e s v i l l e , F L 32610, U.S.A.

OP 21.01

OP 21.03

COMPARISON OF THE CLINICAL PHARMACODYNAMICS OF DEXAMETHASONE, METHYLPREDNISOLONE AND TRIAMCINOLONE ACETONIDE G__~. H o c h h a u s , H. Derendorf, H. Mollmann, C. M_~o!imann, M. Krieq, S. Tunn, J. B a r t h a n d H.J. R6thig The pharmacodynamics of dexamethasone, methylprednisolone and triamcinolone acetonide were investigated after intravenous administration of their respective phosphate e s t e r s in d o s e s of 20, 50 a n d 80 m g in h e a l t h y volunteers. As a reference a placebo treatment w a s i n c l u d e d in t h e s t u d y design. 22 d i f f e r e n t pharmacodynamic parameters were followed as a f u n c t i o n of t i m e for 48 hours. Statistically significant pharmacodynamic effects include i n c r e a s e s in g l u c o s e l e v e l s a n d t h e n u m b e r of s e g m e n t e d c e l l s a n d t o t a l w h i t e b l o o d c e l l s as w e l l as d e c r e a s e s in u r i c a c i d l e v e l s a n d t h e number of lymphocytes and eosinophils. A pharmacokinetic-pharmacodynamic model was d e v e l o p e d a l l o w i n g e x c e l l e n t p r e d i c t i o n s of t h e e f f e c t s as a f u n c t i o n of time. Dexamethasone could be shown to have a clearly stronger effect than methylprednisolone and triamcinolone acetonide which were not significantly d i f f e r e n t . T h e m o d e l e n a b l e d to d i f f e r e n t i a t e the pharmacokinetic and pharmacodynamic contributions to t h e o v e r a l l effects of t h e investigated compounds. Evaluation of the c u m u l a t i v e a c t i v i t y b a s e d on t h e a r e a s u n d e r t h e effect-time-curves showed, that for the i n v e s t i g a t e d d o s e r a n g e a f o u r f o l d i n c r e a s e in t h e d o s e c a u s e s o n l y a l e s s t h a n 50% i n c r e a s e in c u m u l a t i v e e f f e c t f o r a n y o f t h e t h r e e drugs. College of Pharmacy, University of Florida, G a i n e s v i l l e , F L 32610, U.S.A.

SPIRONOLACTONE PHARMACOKINETICS AND PHARMACOD Y N A M I C S IN C I R R H O T I C S W I T H A S C I T E S I. S u n q a i l a , W. Bartle, S. W a l k e r , C. D e A n g e l i s , J. U e t r e c h t , S. C. P a p p a s T h e o b j e c t i v e s of t h i s s t u d y w e r e to d e t e r m i n e pharmaeokinetic and pharmacodynamic parameters of s p i r o n o l a c t o n e ( S P ) a n d m e t a b o l i t e s ( c a n r e n o n e (CAN), 6 ~ - h y d r o x y 7 e - t h i o m e t h y l s p i r o l a c t o n e ( 6 B ) , 7~-thiomethylspirolactone(7A)) in cirrhotics under steady-state conditions. Nine cirrhotics with ascites were entered into the study. S u b j e c t s w e r e to b e s t u d i e d at a m i n i m u m of 2 S P doses. Serial blood and urine s a m p l e s w e r e c o l l e c t e d o v e r a 26 h o u r p e r i o d and a n a l y z e d b y r e v e r s e - p h a s e H P L C for SP, CAN, 6B, 7A, as w e l l as s o d i u m a n d p o t a s s i u m . M a x i m a l c o n c e n t r a t i o n s a n d t i m e at w h i c h t h e s e a r e o b s e r v e d for a i00 m g S P d o s e (n=6) w e r e 73.1• n g / m l a n d 3 h o u r s for SP, 1 0 4 . 1 • n g / m l a n d 6 h o u r s for 6B, 4 5 9 . 7 • ng/ml and 3 h o u r s for 7 A a n d 3 0 3 . 9 • n g / m l and 4 h o u r s for CAN. The terminal phase half-lives (n=9) for SP, 6B, 7A a n d C A N w e r e 1 3 9 . 6 • hours, 279.1• hours, 4 2 . 8 • h o u r s and 7 4 . 5 • hours, respectively. AUC for SP increased linearly with increasing dose. In urine, 1.7• of t h e S P d o s e w a s e x c r e t e d as CAN, 1.1• as 6B, 0 . 3 • as 7 A a n d 0 . 0 5 • as SP. U s i n g m a s s s p e c t r o m e t r y , all c o m p o u n d s w e r e verified and 2 unknown peaks were identified. SP m e t a b o l i s m is i m p a i r e d in c i r r h o s i s ; t e r m i n a l h a l f - l i v e s of SP a n d m e t a b o l i t e s a r e i n c r e a s e d b y 7 - 1 0 0 fold. W h e n a s s u m i n g a l i n e a r model, c l e a r a n c e - e f f e c t r e l a t i o n s h i p e s t i m a t e s are b e s t c o r r e l a t e d w i t h 7 A a n d CAN; a p p r o x i m a t e l y 60% of S P ' s e f f e c t is a t t r i b u t e d t o 7 A a n d 15% t o CAN. Sunnybrook Medical Centre, Departments of Pharmacy and Medicine 2075 Bayview Ave., Toronto, Ontario, M4N-3M5.

A 73

OP 21.04

OP 21.06

PLASMA CONCENTRATION EFFECT RELATIONSHIPS FOR FELODIPINE D Elmfeldt, E Blychert, C Dahl0f, T Hedner.

DOSE/PLASMA CONCENTRATION/EFFECT RELATIONSHIP OF FELoDIPINE ON SINGLE PLASMA SAMPLES IN A LARGE CLINICAL STUDY G. Tibblin and B. Edgar for the Swedish Multicentre Group Pharmacokinetic compound data is usually evaluated from small studies with often less than a dozen individuals9 It has therefore been suggested that a low plasma samples from each individual in a large population should be used to e,,[ovide additional information on the pharmacokinetics. Fel0dipine (Plendil '~ , F) a selective antihypertensive calcium antagonist has been shown to have an absorption linear to the dose in several smaller studies in healthy subjects. A close correlation between plasma concentrations and effect on blood pressure has been shown. Method: In a double-blind study in 251 hypertensive patients (mean age 57 years) concomitantly treated with a ~-blocker ~theeffect of different doses of F (5, 10, 20 rag) once daily was compared with that of placebo. After 4 weeks' treatment a single plasma sample was drawn 24 h after last tablet intake. Blood pressure was measured simultaneously. Results: There was a linear reduction between dose and trough plasma concentrations, see table. The dose adjusted plasma concentration increased with age. The distribution of trough plasma concentrations in this population was skewed but unimodaL A Mean base- Mean Mean maltiregression analysis Dose n line DBP /,DBP Cmin of the response in alia(rag) (mmHg) (rnmHg) (nM/mg) alolic BP showed that this depended on initial diaP 62 1014-5 -1.6 stolic pressure, F plasma s 62 102+5 -5.8 0.48 concentration and age. 10 56 1024-5 -7.5 0.39 The dose giving the best 2o 58 192• -9.1 0.38 relation between effect and tolerance was 10 mg. Conclusion: Single plasma samples taken in larger clinical studies together with assesments of pharmacodynamio response provides additional information about: - dose linearity .genetic differences 9plasma concentration/effect relationship 9importance of age. Depts. of Family Medicine, Akademiska sjukhuset, Uppsala, Sweden and Clinical Research, Astra CV, AB H~issle, S-43t 83 M(SLNDAL, Sweden

Oral treatment with the dihydropyddine calcium antagonist felodiplne (F) was given double-blind In a cross-over design to compare once daily doses of 20 mg F extended release (ER) tablets with placebo in 12 hypertensive patients already treated with a 8-blocker. A 2-hour i.vinfusion of F was given after a placebo wash-out period. During the oral F period systolic and diastolic blood pressures (BP) were significantly'lower than during placebo treatment, both after the first dose and during steady state. After the first dose of F the supine BP 24 hours after dose was 159/97 and 153/92 mmHg (p<0.01/0.05) after placebo and felodipine treatment, respectively. The corresponding BP:s at steady state were 158/99 and 144/89 mmHg (p<0.01/0.01). The mean plasma concentration (Cp) of F vs time curve after oral administration was relatively flat. A linear correlation was found between BP-reduction and the logarithmic Cp. The Cp after i.v administration correlated well with a hyperbolic function. These data indicated that fhe~e isan almos! tinear ,elation beh,,,een BP reductio~ and logarithmic Cp for F in the range from 1-20 nM, and that little additional effect is to be expected above approximately 20 nM. Hysteresis analyses for systolic and diastolic BP indicated that the Cp of F is in equilibrium with the F concentration at the site of action. The mean absolute bioavailability of F ER was 22% after single dose as well as steady state treatment. The terminal half-life of F, determined after the Lv.-admintstration, was 15+2.6 hours. Department of Clinical Pharmacology, Sahlgrenska Hospital, S-413 45 GSteborg, Sweden.

OP 21.05

OP 21.07

TROUGH-TO-PEAK RATIO OF FELODIPINE - AN ESTIMATE OF THE EFFICACY OVER THE DOSAGE INTERVAL B. Edgar, D. Elmfeldt, E. Falson and D. Shapiro It has been suggested that the relative efficacy of an antihypertensive drug throughout the dosing interval should be examined. The proposal was that the drug's efficacy at trough should be no less than 50% of the peak effect. Data on the trough-to-peak (T-P) ratio have been gathered in clinical tdals with felodipine (F), a dihydropyddine calcium antagonist with high vascular selectivity, F appears to have a close relationship between its plasma concentration and its efficacy. Method: The TP ratio for plain tablets (PT~ given b.i.d, and extended~ E R ) tablets of felodipine (Plendil ~ given o.m. has been analysed both dudng monotherapy and treatment in combination with a J~-blocker in placebo-controlled dose-response studies. The TP ratio has been calculated from unrounded BP values, but the changes in BP shown below have been rounded for clarity. Peak effect is 1-4 hours after dosing, trough: 24h (ER) or 12h (PT) after dosing. Results: Effect of felodipine 10 mg/day on resting supine diastolic blood pressure at trough and peak and the TP ratio are given in the table. Different doses of F do not change the TP ratio. Placebo has a TP ratio varying between zero and 58%.

INFLUENCE OF EXTREME O B E S I T Y ON THE BODY D I S P O S I T I O N AND C U R A R I Z I N G A C T I O N OF A T R A C U R I U M

Study Type of study

Mean change (mmHg) Mean change (mmHg) TP (trough) (peak) (%)

mono mono

-9 -7 -12 -9

PT ER PT ER

-16 -15 -20 -16

56 44 60 55

Conclusion: Felodipine ER given once daily is characterized by a similar trough to peak ratio as plain tablets given bid.. Usually more than 50% of the peak effect is still available at trough. Astra CV, AB H&ssle, S-431 83 MOLNDAL, Sweden, and Merck Sharp and Dohme Research Laboratories, West Point PA, USA

Pharmacokinetic studies in morbidly obese p a t i e n t s are scarce, especially when referring to n e u r o m u s c u l a r blocking agents. A l t e r a t i o n s in body c o m p o s i t i o n in these p a t i e n t s may m o d i f y the d i s p o s i t i o n of a t r a c u r i u m (Atra) and further increase the risk of respiratory c o m p l i c a t i o n s secondary to anesthesia. Nine obese (X: 129 kg) and 9 non-obese (X: 60 kg) p a t i e n t s were included in the study. After the induction of anaesthesia, intubation was facilitated by i.v, a d m i n i s t r a t i o n of s u c e i n y l c h o l i n e (Suc). Traino f - f o u r stimulation was a p p l i e d to the u l n a r nerve and the force of c o n t r a c t i o n of the a d d u c t o r pollicis m u s c l e was measured. After recovery from Suc blockade, an IV bolus of Atra was injected (0.2 mg/kg). Blood samples were w i t h d r a w n at different intervals for up to 2 hours. The v o l u m e of d i s t r i b u t i o n (Vdss, L/kg) was 47% smaller in obese than in non-obese patients. A l t h o u g h a 46% decrease in clearance (L/h/kg) was o b s e r v e d in obese patients, the a b s o l u t e value (L/h) was unchanged,, suggesting an intact metabolic capacity. The m e a n residence time of Atra was unchanged. The onset of neuromuscular blockade was faster in obese p a t i e n t s but its d u r a t i o n of action was not significantly prolonged. Plasma c o n c e n t r a t i o n s at 50% recovery of muscle twitch were significantly higher (52%) in obese. Hence, larger c o n c e n t r a t i o n s of Atra are required in obese patients to a c h i e v e similar levels of blockade, and a dose c a l c u l a t e d on a mg/kg basis should be adequate. Before it can be c o n c l u d e d that obese patients are more resistant to the action of Atra, the p l a s m a free f r a c t i o n has to be determined. (MHC MA-I0274) Facult4 de Pharmacie, Univ. de Montr4al, 2900 E d o u a r d M o n t p e t i t , S u c c . A , C P 6128,H3C 3J7,Canada.

A 74

OP 22.02

OP 21.08 FUROSEMIDE (FUR) HEPATIC CIRRHOSIS

PHARMACODYNAMICS

IN

PATIENTS

WITH

P. du Souich *, A. Sanchis Closa+~ C. Lambert R To investigate the influence of hepatic cirrhosis on the response to FUR, i0 patients with cirrhosis (CIRR) (class B and C) and i0 healthy volunteers (HV) received 40 mg of FUR i.v. and multiple blood and urine samples were collected to assay FUR, Na ~ and creatinine. In CIRR, Na + plasma concentration and creatinine clearance (137 • 2 mmol/L and 68 • 5 mL/min; • SEM) were lower than in HV (142 • 1 mmol/L, p<0.0 ! and ii0 • 3 mL/min, p
OP 22.01

Solid tumor growth has an absolute dependency on angiogenesis (J. Folkman, Presp. in 8 i o i . and Med., 29,10, 1985). 8,9-dihydroxy-7-methyl-benzo(b)quinolizinium bromide (GPA 1734) and tricyclodecane-9-yl-xanthate (D609) are basement membrane synthesis i n h i b i t o r s in the in r i v e and/or the i n # i t r o chick c h o r i o a l l a n t o i c membrane system and have been found to prevent angiogenesis in the same system in #i#o (M.E. Maragoudakis et a l . , J.Pharmacol.Exp.Ther., 244,729, 1988 and M.E. Maragoudakis et a l . , J.Pharmacol.Exp. Ther., subm. for publ., 1988). In the present study we have demonstrated that these compounds have potent antitumor effects in the Walker 256 carcinosarcoma model. In control animals, i0 mg of tumor mass implanted in the peritoneal c a v i t y formed numerous macrometastases and grew to about 17 g within eight days. Animals treated with GPA 1734 (12.5-100.0 mg/kq) or D609 (12.5-50.0 mg/kg) prevented the formation of macrometastases and restrained tumor growth. The dose-dependent effects of these compounds on tumor growth and macrometastasis indicate that basement membrane synthesis may be a novel target for developing antiangiogenic compounds with antitumor properties. This approach to tumor therapy w i l l be without any toxic consequences to normal cells since basement membrane synthesis and angiogenesis are extremely slow processes under physiological conditions (J. Denekamp, Br.J.Cancer, 45,136, 1982). Department of Pharmacology, School, Patras, Greece.

University of Patras

Medical

OP 22.03

A NEW TU~OR-PHOTODYNAMIC V. N. Z alessky

ANTITUMOR PROPERTIES OF ANTIAGIOGENIC COMPOUNDS G.D. Karakiulakis, E. M i s s i r l i s and M.E. Maragoudakis

THERAPY

DRUGS

~ I. A. Mikhalkin

For a number of years the mixture hemstoporphyrln derivative (HpD) end its purified version, P h o t o f r l u - I I have been utilized in the ares of photodyuamic therapy of cancer. A second geueration of drugs which includes derivatives of tetrapheuylperphiue and chloriu have recently been found to have some advantages over these traditional compounds. The effect of continuous-wave argon laser radiation on the growth of solid Ehrich carcinoma was studied in mice. To enhance the blastoma sensitivity to laser radiation compounds of a porphyrin series were glveu to animals prior to the laser treatmerit. Out of 14 tested drugs tetraphenylporphyu sulfouate, its p a l l a d i u m complex and sodium t e t r a p h e u y l s u l f o n a t c h l o r i n u m (tumor growth inhibitleu by 82.0%, 78.2% and 76.5%, respectively) had the most pronounced photosensitizing effect to such of HpD (75.9%). Metallic complexes tetrsphenylporphyn, protop o r p h y r i u and tetrssulfophtalocyanid were less sotivlty. It is coucludent that porphytins are p r o m i s i n g seusitizers for elaborating methods for tumor photodyuamie therapy. Based on these results, more intensive pharmacological and oucological tests of the preparation are in progress. ~.E.Kavetsky Institute of Oucology Problems, Academy of Sciences of Ukrainian S.S.R., Vasilkovskejs, 45, 252127, Kiev-127, U.S.S.R. ~Iustltute of Otorhyuolaryugology, Department of ENT-encology, Zoolegieheskajs Str., 3, 252057, Kiev-57 U.S.S.R.

PHARMACOLOGICAL CHARACTERIZATION OF VASOACTIVE INTESTINAL PEPTIDE (VlP) RECEPTORS IN NORMAL HUMAN BREAST GLAND AND HC-11 IMMORTALIZED MOUSE MAMMARY EPITHELIAL CELLS. P. Ber~h0q1, F. Calve 1, P. de Cremoux 1, V. Delbourg 2, J-L. Taillemite 2, R. Ball3, G. Lacier 1 and C. Gesoach 2 We have previously identified specific membrane receptors for the neuropeptide VlP in eight human mammary cancer cell lines (Cancer Res. 48 : 5079, 1988). In the present study, several samples of long term culture (5 to 6 months) of human mammary epithelial cells derived from reduction mammoplasty or male gynecomastia were tested. These specimens are cultured with low serum concentrations, low Ca2+-containing medium supplemented with hormones and growth factors. These normal cells were used after 30 d a y s in culture and were clearly epithelial since they exhibit typical tight junctions under electron microscopy and were stained at 100% with mAb against cytokeratins. Moreover, they were positively stained with the DF3 and 7 B I 0 mAbs specific for antigens associated with the mamary gland. These primary breast epithelial cells display typical VlP receptors coupled to cAMP production (3-5 fold increase of basal activity, EC50 = 10 10 M VlP), according to the following pharmacological specificity, tested with the natural VlP analogs : VlP > helodermin > helospectrin > PHM > PHV > hpGRF > secretin. Similarly, VlP and its agonists activate 2-fold cAMP generation (EC50 = 1.5 x 10 -9 M VlP) in the mouse HC-11 cell line, with the following order of potency : VlP, PHI, helodermin > PHV > rhGRF, secretin. These results argue for a regulatory role of VIP in normal and immortalized mammary epithelial ceils originating from man or rodents. 1Pharmacology Laboratory and INSERM U204, Hbpital Saint Louis, F-75010 PARIS; 2 INSERM U55, Hbpital Saint Antoine F-75012 PARIS; 3Friedrich Miescher Institute CH4002 BASEL.

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IN VIVO MODEL FOR INTERACTIONS WITH M E T H O T R E X A T E J. Aarbakke, R. M. Bremnes, L. Sl~rdal and E. Wist In vitro studies have shown that the extent of 7 - h y d r o x y - m e t h o t r e x a t e (7-OH-MTX) formation in liver extracts of rats is, compared to that of rabbits, in better agreement with biotransform a t i o n in human liver tissue. We questioned the a p p l i c a b i l i t y of rabbits in evaluation of 7-OHMTX pharmacokinetics, and present studies on in vivo 7 - h y d r o x y l a t i o n in rats. Bile, urine, and serum concentrations of m e t h o t r e x a t e (MTX) and 7OH-MTX were monitored in rats following 10 mg/kg (3HJ-MTX i.v.. The experiments were performed in anesthetized, b i l e - d r a i n e d rats and in undrained controls. Peak b i l i a r y levels of MTX (3.8 mM) and 7-OH-MTX (0.18 mM) appeared within 15 min after short-term infusions. For 2 log ranges of serum MTX concentrations, biliary levels remained 180-fold higher. High bile 7-OH=MTX levels appeared few min after MTX administrationr and were 720 times higher than the peak serum concentrations, indicating that the liver is a major site of 7-OH-MTX formation in rats. 7-OH-MTX concentrations in bile declined m o n o p h a s i c a l l y (TH2 29.4 min), while MTX showed a biphasic elim i n a t i o n (Tll2 23.1 and 86.4 min). Bile was the major excretory route for MTX and 7-OH-MTX. 50% of the dose was recovered as the parent compound and 3.6% as the metabelite. Equal urinary recovery of MTX in b i l e - d r a i n e d and control animals, and the u r i n a r y MTX recovery of only 2.1% in rats receiving MTX-containing bile through a d u o d e n a l catheter, is indicative of an insignificant enterohepatic c i r c u l a t i o n of MTX. The animal model can be applied in studies of interactions with inn vivo MTX conversion to the 7-hydroxy metabolite. Department of Pharmacology, U n i v e r s i t y of T r o m s m N-9081, Tromso, N o r w a y

CYTOTOXICITY OF VINBLASTINE AND CARBOPLATINUM CAN BE ENHANCED BY ADDITION OF R-VERAPAMIL (R-VPM) AND BY BUTHIONIN SULFOXIMIN (BSO) IN PRIMARY HUMAN RENAL CELL CARCINOMA (RCC) G.H. Micklsch, R.K. Tschada, G. Keilhaner, E. Schlick, P.M. Alken Inlrinsic chemoresistance conu-ibutes to the poor prognosis of patients with disseminated RCC. Among other genetically fixed mechanisms of resistance, multidrug resistance (MDR) and the glutathion redox eyrie play an important role in RCC. The P- 170 glycoprotein related efflux pump in MDR may be modified by calcium antagonists; gintathion (GSH) depletion may result from inhibition of OSH-synthetase by BSO. Thus, we submitted 21 primary human ROCs resistant to Vinblastine (VBL) and Carbopla~num (CP) to a mieroeulture tetrazolium assay (MTT), and studied the effect of Vempamil (VPM), its (+)-enantiomer (R-VPM), and of BSO. Each calcium channel blocker was tested at concentrations ranging from 0, l to 100 }~Min presence of 0, I ~tg/ml VBL or 0,75 ~tglmlCP. BSO was incubated at 200 laM for 24h prior to application of antincoplas~c agents. Total cytotoxic drug exposure time reached 7211;MTT was then added for further 4h, and optical density measured at 540 nm. VPM and R-VPM caused a 50 to 100 % decrease of viable tumor cells as compared to VBL alone. CP-resistance was reversed to a smaller degree (30 - 60 %). BSO incubation led to a sirens enhancement of CPcytotoxidty (200 - 300 %), whereas VBL-toxicity was only moderately intensified (40 - 100 %). We conclude that the interactionof ehemotherapeutics with chemo~nsitizing agents may well offer new therapeutical options in RCC. Particularily, the new formulation R-VPM with a tenfold lower cardiotoxicity (than VPM) but similar enhancement of cytotoxieity opens the opportunity to realize potentially tumor effective serum levels - tolerable in

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1-25(OH)2 VITAMIN D3 [1-25(OH)2 D3] INCREASES STIMULATED ADENYLATE CYCLASE ACTIVITY (ACA) AND SYNTHESISOF STIMULATORYG PROTEIN (Gs) IN THE HUMAN BREASTCANCER CELL LINE T-47D.

Withdrawn

P. de Cremoux, F. Calve, C. Gauville, G. Lagier, J-P~ Abita and P. Lechat.

We have shown that 1-25 (OH)2 D3 inhibits the proliferation of the human breast cancer cell line T-47D and increases stimulated cyclic AMP production in these cells. To determine the mechanism of action of this hormone, we have cultured T-47D cells for two days in the presence or absence of 1-25 (OH)2 D3 and measured in both cells: a) the plasma membrane ACA in the basal state and after stimulation by -forskolin (10 -4 M) which activates directly the catalytic subunit, and -vasoactive intestinal peptide (VIP, 10-5 M)which stimulates the ACA after binding to specific membrane receptors present in T-47D cells; b) the number of VIP binding sites and their dissociation constant; c) the extent of cholera toxin ADP ribosylation of the a subunit of Gs. We show that 1-25 (OH)2 D3 increases 1.8 to 1.95 fold stimulated ACA in treated TL47D cells but does not modify either the number of VIP binding sites (10000/cell) or the Kd (5.35 + 2.2 x l 0 -lo M). This activation is due to an increased synthesis of Gs as demonstrated in the autoradiograms of gel electrophoresed a 32p labeled Gs.

Pharmacology Laboratory and INSERM U204, HSpital Saint Louis, 75475 PARIS Cedex 10, FRANCE.

marl.

Dep. of Urology, Mannheim Hospital, Univ. of Heidelberg, TheodorKutzer-Ufer, D-68 Mannheim, FRG

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OP 22.08 THE EFFECT OF ORGANIC ANIONS AND CATIONS ON THE RENAL TUBULAR TRANSPORT OF CISPLATIN. Julia Klein, Gideon Koren, Yedidia Bentur, Derrick Chung, Galina Moselhv. Cis-dichlorodiammineplatinum II (cisplatin) is a widely used antineoplastic agent. Its clinical use is hindered by a broad range of nephrotoxic effects from renal tubular defects to acute renal failure. Previous studies suggest that cisplatin is secreted by the renal tubules. By using organic anions and cations, we tried to block secretion and therefore potentially counteract the nephrotoxic effect of cisplatin. To study the mechanism of renal handling of this drug we employed several research approaches, a) Clearance studies in dogs documented that free cisplatin has a high clearance, exceeding glomerular filtration rate. The drug appears to be secreted both by the anionic and cationic transport system in the proximal tubule, as the fractional clearance of free platinum is markedly decreased by the administration of 100 mg/kg probencid (from 1.37 + .21 to .83 + .18, p < .025). When probencid infusion stopped, the free fractional clearance increased (from .83 + .18 to 1.31 + .15, p < .025). When 100 gg/kg quinidine or 20 mg/kg cimetidine were administered, the same phenomenon was observed: The free fractional clearance of cisplatin decreased (from 1.56 + .44 to 1.07 +_.19, p < .05). When the infusion of these cations stopped the free fractional clearance rebounded (from 1.07 +_,19 to 1.31 +_.34, p < .05). b) Using brush border membrane vesicles prepared from dog kidney, we doc"amented that cisplatin inhibits in a concentration dependent fashion the transport of p-aminohyppurate (inhibition between 26.5 - 50% when cisplatin 0.5 m M - 2 mM was used) as well as the transport of N-methyl nicotinamide (inhibition 0 - 35% when cisplatin 0.5 mM - 2 mM was used) by the brush border membrane vesicles. These studies suggest that both anionic and cationic blockade decrease the tubular secretion of cisplatin. Clinical studies are needed to see if this blockade will prevent cisplatin nephrotoxicity. Supportedby MRC grant MA 8544. Division of Clinical Pharmacology, Hospital For Sick Children, 555 University Avenue, Toronto, Ontario, Canada, M5G 1XS.

PHARMACODYNAMICS AND PHARMACOKINETICS OF CICAPROST, A METABOLICALLY STABLE PGIg-MIMETIC , IN VOLUNTEERS AFTER ORAL A D M I N I S T R A T I O N OF 5 TO 20 NG M. Hildebrand and Th. Staks Cicaprost is a chemically and m e t a b o l i c a l l y stable prostacyclin-mimetic. After oral dosage, the compound is completely bioavailable in man. Six healthy male volunteers were treated with Cicaprost tablets at dosages of 5, i0, 15 and 20 Ng. Doses were increased according to individual tolerability. Plasma levels of Cicaprost, facial colour and inhibition of platelet aggregation were measured. Peak plasma levels were reached within 0.25 to 1.5 h. Both C and AUC-values were dose .ma dependent. Termlna~ half-lives were approx. 1 h. Total clearance was 4 - 7 ml/min/kg. Changes of facial colour, inhibition of platelet aggregation and side effects (e.g. head-ache) were interindividually different. Chromametric and aggregemetric results correlated well with plasma level profiles. Platelet aggregation was dose-dependently inhibited up to a m a x i m u m of 40%. Cicaprost is a potent oral PGIg-mimetie with effects on platelet aggregatio~ and vascular perfusion at dosages of 5 to 10 ~g.

Research Laboratories, Schering AG, M~llerstr. 170-178, D-1000 Berlin 65 (FRG).

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THE FIRSTUSEOF A NEW ORAL PGI2-DERIVATIVEONHEALTHYVOLUNTEERS SJL~k~.T. and Seifert. W. Since the intravenous use of the first stable PGl2-derivativas, the wish has been expressedby clinicians for longer-acting compoundsfor peroral administration.

LONG TERM TOPICAL TREATMENT OF THE PGI2 - DERIVATIVE ILOPROST ON HEALTHY VOLUNTEERS. A. Keesk6s, P. Jahn, L. Lange Single topical application of an aqueous solution of Iloprost induces a loagterm ( > 24 h) erythema probably due to marked vasodilatation. The aim of this study was to investigate the local tolerability of Iloprost and the possibility of the development of tachyphylaxisin an open study design in eight healthy male volunteers. 1 ml of the aqueous solution containing 50 ug noprost was applied once daily on a skin area of 100 era2 on the back of the subjects for 60 consecutive days. After the solution was dried hy cold air, the treated area was occluded for 4 hours. The followingevaluations were performed to estimate the incidence and degree of erythema: Visual evaluation according to a grading score from 0 - 3. Superfieial skin temperature was measured by touchless infrared tliermography. Increased perfusion in subepidermal vascular plexus was recorded by Laser Doppler Flowraeter. Additionally subjective parameters like burning itching or feel{rigof pain were recorded. In all cases a marked er,/thema wasgenerated whichlasted till the next application. An erythema due to inflammation would show additional symptoms such as edema, pain and/or itching, iloprost erythema did not develop any of these symptoms. A relevant increase of skin temperature (up to 3 *C) compared to untreated areas was also measured. A marked increase of skin perfusion was found by Laser Doppler Flowmeter, often twice as much as in the control. These effects were seen over the whole treatment period. Taehyphylaxisdid not occur. After the end of treatment Iloprost erythema disappeared completely within 72 hours. Our present results suggest that Iloprost erythema is induced by an isolated vasodUatatory effect. These findingsencourage further testing of long term topical applications of Iloprost in patieuls with skin disorders.

With CICAPROST a new PGl2-derivative is now available. Pharmacological the compound displays a high potency in respect of inhibition of throrabocyte a~gregatlon, Cicaprost is pharmaceutically formulated as an inclusion compound wlth B-cyciodextrin (="ciathrate"). The purpose of the study was to demenstrate, in addition to the tolerance, the effects their duration. Cicaprost was administered as an aqueous solution to a total of 16 healthy male volunteers, In the group conparison (o:2), the individual doses were increased in a placebo-controlled design from 7 (0.41 ~ ) to 252 ng/kg BW (20 tag). The proof of the effect was obtained by the measurement of the skin color of the forehead as a measure of the vasodliatation and of the inhibition of the ADP-induced thrombocyte aggregation. Clinical and hematological parameters were also studied. RESNLTSOF STUDY: Cicaprost has a duration of approx. 2-4 hours (until the attainment of the pretreatmant situation). The cora~encement of aggregation inhibition is apparent from a dose of 56 ng/kg 4 ~ ) . An inhibition of aggregation to about 50 % of the pretreatment situation with a maximum effect at about 40 mins. p. appI. can be achieved in a dose-related manner. Correlatively with the aggregation, the skin on the head and neck turns red as a sign of evident vasoddatation (Fig, I ) . After the onset of vasodilatation and aggregation as the expression of the desired effects further PGI2-typical effects occur at h gher dosages. The dose range should be <200 ng/kg BW (: 15 lag) and with multiple doses the ihtervai of at least 4 hours should be observed. The laboratory parameters do not display any clinically relevant changes. The high pharmacological potency or the PGl2-derivative expected from the veterinary pharmacological characterized was confirmed on healthy volunteers, A very promising, non-retarded oral formulation is therefore available.

BW(:

COLOR-DEViATION OFFOREHEAD SKIN DELTAX,- Y; ClC,~ROST;112ng/kgBW; I [ / YELLOW] 0 -10

-10

Department Humanpharmakologle II, Schering AG, Mis 171, D-1000 Berlin 65

~,10 , N8~I~M2 0p.c;. ~ [ O d~z,3o0 ~x200 ~ ~0o

6R ~40~

- 20

400

INHIBITIONOFAGGREGATION CICAPROSI1; !2 ng/kgBW SUBJECT8

DELTAX 10

0

SUBJECT19

MIN. xo.20 60 100 150 210270 330 420 600 1440

Fig,1 Vasodilatation by chromametry Fig. 2 Inhibition of aggregation Uumenpharnacology I, Schering AG, Miillerstr. 171, D-IO00 Berlin 65

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Withdrawn

EFFECT OF THE THROMBOXANE RECEPTOR BLOCKER DALTROBAN ON PROSTAGLANDIN INDUCED CONTRACTIONS IN DIFFERENT TISSUES OF THE HUMAN UROGENITAL TRACT A. H e t t e n b a c h , L. D 6 r g e , K. S t e g m e i e r , H. P a t s c h e k e P r o s t a g l a n d i n s a r e i n v o l v e d a s p o t e n t m e d i a t o r s in normal and pathological pregnancy and may also play a r o l e in m a n y p r o c e s s e s c o n c e r n i n g t h e h u m a n u r o g e n i t a l t r a c t . We s t u d i e d t h e e f f e c t s of P G F 2 a l p h a , t h e t h r o m b o x a n e mimetic U 4 6 6 1 9 , a n d t h e t h r o m b o x a n e r e c e p t o r b l o c k e r d a l t r o b a n in d i f f e r e n t t i s s u e s ofthe human urogenital tract such as pregnant and non p r e g n a n t m y o m e t r i u m , t u b e s , a n d u r e t e r in v i t r o . In p r e g n a n t a n d n o n - p r e g n a n t m y o m e t r i u m d a l t r o b a n h a d no e f f e c t on t h e s p o n t a n e o u s c o n t r a c t i o n s b u t r e d u c e d t h e i n c r e a s e in c o n t r a c t i l e a c t i v i t y i n d u c e d b y P G F 2 a l p h a or U 4 6 6 1 9 in a c o n c e n t r a t i o n - d e p e n d e n t m a n n e r . D a l t r o b a n w a s u n e f f e c t i v e in r e d u c i n g a m p l i t u d e s or f r e q u e n c y of o x y t o c i n i n d u c e d c o n t r a c t i o n s in p r e g n a n t m y o m e t r i u m s t r i p s a n d did n o t i n c r e a s e t h e i n h i b i t o r y e f f e c t s of t h e ~ - m i m e t i c f e n o t e r o l . In t h e h u m a n t u b e s p o n t a n e o u s a c t i v i t y w a s a t t e n u a t e d b y 1M d a l t r o b a n . U 4 6 6 1 9 (80 nM) or P G F 2 a l p h a (10 M) c a u s e d a n i n c r e a s e in r e s t i n g t o n e f a r e x c e e d i n g t h a t in p r e g n a n t m y o m e t r i u m b u t did n o t c h a n g e f r e q u e n c y or a m p l i t u d e of c o n t r a c t i o n s . S t i m u l a t i o n of h u m a n u r e t e r r i n g s b y t h e s e c o n t r a c t i l e p r o s t a g l a n d i n s r e s u l t e d in i n c r e a s e d r e s t i n g t o n e , f r e q u e n c y a n d a m p l i t u d e s a n d c o u l d be b l o c k e d by daltroban. T h e s e r e s u l t s s u p p o r t a r o l e of c o n t r a c t i l e p r o s t a g l a n d i n s in p h y s i o l o g i c a l or p a t h o l o g i c a l p r o c e s s e s in t h e h u m a n u r o g e n i t a l t r a c t c h a r a c t e r i z e d b y a n i n c r e a s e d c o n t r a c t i l e a c t i v i t y . In c a s e of p r e t e r m l a b o u r , d y s m e n o r r h o e or i n f l a m m a t i o n i n d u c e d u r e t e r s p a s m s t h r o m b o x a n e r e c e p t o r b l o c k e r s m a y be of t h e r a p e u t i c Value. F r a u e n k l i n i k u. I n s t . f. K l i n i s c h e Chemie, K l i n i k u m Mannheim; B o e h r i n g e r M a n n h e i m GmbH, Med. Res. Dept., S a n d h o f e r s t r . 116, D - 6 8 0 0 M a n n h e i m , FRG

OP 23.05

OP 23.07

SPECIFIC THROMBOXANE A ~ (TX?) ANTAGONIST IN ACUTE ISCHEMIC RENAL FAILURE 7 A R F T IN RATS.

TRAUMA INDUCED ALTERATIONS OF PLASMA PROSTANOID LEVELS IN INTENSIVE CARE PATIENTS T. Alexandridis, P. Kessler, R. Kirsten, R. Lissner, A. Thrun, U. Schwul~ra

The role of TXA 2 potent renal vasoconstrictor, in the pathogenesis of ARF, was assessed, using the specific TXA2-receptor antagonist (L 655,240). ARF was induced mn Sprague-Dawley rats by RT nephrectomy and subsequent clamping of Lt renal pedicle for 60 mins. Saline, Indomethacin (5mg/Kg) or L655,240 (lOmg/Kg) were administered I.V. 15-30 min before and during the ischemia phase. No statistically significant differences were observed in S. urea, creatinine, urine volume and creatinine clearance obtained one day after the ischemia in the three treatment groups. In addition PGE 2 & ATP were examined in the Rt non-ischemic (C) renal cortex & in Lt renal cortex 24-Hrs following ischemia. PGE 2 ATP Rt (C) Lt (I) Rt (C) Lt (I) .................................... Saline ii.841.2 ND 12.1• 8.9~1.4 Indomethacin ND ND i0.7~0~ 8.1~1.4 L 655,240 13.7• 7.7+0.6 13.8• 13.3• ND= Non-detectable. C = Control. I = Ischemia. All data are given as Means + SEM. Thus, pre-treatment with specific TXA7 in rats considerably improved renal tissue ATP & PGE~ content, indicating an alleviation the effect of isch~mia on the renal cortical cell.Howe~er, this beneficial effect of L 655,240 is not demonstrated by conventional renal function parameters in this setup of experiments.

The early hypovolaemic-traumatic and the late septic shock which is often associated with multi-organ failure, are triggered by several humoral and cellular systems. It has been suggested, that many of these tratlma-induced dysfunctions are mediated by products of the cyclooxygenase pathway. The purpose of these study was to evaluate changes of plasma prostanoid levels arising through trauma and sepsis. Monitoring procedures included determination of plasma levels of PGE2, PGF2~, TxB2 and 6-keto-PGF1 ~, in 21 (11 0 and 10 0 , mean age 46,09 years) intensive care patients. The patients were recruited for the study in~ediately after admission to a intensive care unit and prostanoid screening was carried out at day 1,2,3,4,6,8,10,14 and 21 post trauma. Plasma samples were assayed radioinmunologically. Statistics were calculated by Wilcoxon~s test. The measured plasma concentrations of all prostanoids in patients were above no~aal r~ges. PGE2 p!a~na values ranged frc~ 8.3-80.8 pg/ml, PGF2a from 0.17-2.98 ng/ml, TxB2 frc~ 0.14-4.15 ng/ml and for 6-keto-PGF1~ from 0.17-2.93 ng/ml. Median values of all prostanoids, showed after a marked increase at the onset of the study, a decline at the end of the investigation period, in the survivor group. The results demonstrate an enhanced release of arachidonic acid metabolites in the circulation of patients following trauma and sepsis. Furtller the data indicate a correlation between plasma prostanoid levels and clinical course of the patients. The interpretation of these data is cemplicated by interfering factors which influence prostanoid release, such as anaesthesia, blood transfusion and steroid therapy. Department of Clinical Pharmacology, University Clinic of Frankfurt/Main, sandhofstr. 74, FRG

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OP 24.02

ARE PROSTAGLANDINS (PG) A N I N D I C A T O R OF A C E T Y L CHOLINE (ACH) R E L E A S E I N T H E B R A I N I N V ! V O ? O. P l e u l ~ L. R e s t , U. B i c k e l a n d T. T h o m s e n The reduced availibility of A C h r e p r e s e n t s a mean feature in senile dementia of Alzheimer type (SDAT) and several other neurological disorders in the CNS. One of the possible therapeutic approaches is to increase the t u r n o v e r of A C h b y d r u g s , i.e. t h e t r a n s m i t t e r s synthesis and release. However, until now there is no method to estimate the postsynaptic e f f e c t of r e l e a s e d A C h . S i n c e several authors r e p o r t e d , t h a t A C h i n d u c e s t h e r e l e a s e of P G i n vitro, w e t r i e d to v e r i f y t h e h y p o t h e s i s that P G l e v e l s c o u l d f u n c t i o n as a n i n d i c a t o r of A C h release in vivo, using tetrahydroaminoacridine (THA) as a p o t e n t a g e n t f o r ACh release and inhibitor of ACh esterase. After intravenous application of T H A i n r a t s t h e c o n c e n t r a t i o n of A C h a n d P G i n b r a i n a r e i n c r e a s e d 2 f o l d a n d as to 100fold respectively. The dose-response curves of this effects were running in a parallel m a n n e r , E D 5 0 for A C h w a s 2.2 mg/kg, and for PG 3.3 m g / k g THA. T m a x f o r the ACh increase w a s r e a c h e d at i0 min, for the PG increase at 3 min after THA. Atropine or scopolamine, even in high doses, blocked the effect o n ACh, but not on PG levels. The nicotinic inhibitor mecamylamine did not i n f l u e n c e t h e T H A e f f e c t s at all. I n d o m e t h a c i n , an inhibitor of cyclooxygenase, abolished the enrichment of PG entirely but does not influence ACh levels. The relation of THA treatment and a l t e r a t i o n of PG turnover is still not fully understood. Institut f~r Klinische Pharmakologie der Freien Universit&t Berlin, Hindenburgdamm 30, D - 1 0 0 0 B e r l i n 45 W e s t

EVALUATION OF THERAPEUTIC DRUG MONITORING IN THE PAEDIATRIC EPILEPSY CLINIC. J. Botha, R. Miller and M. Moodley

Over the course of one year, fifty nine epileptic children aged between two and eleven years were entered into an anticonvulsant therapeutic drug monitoring programme at King Edward VIII Hospital in Durban, South Africa. Using Bayesian forecasting and steady state serum anticonvulsant levels measured during routine care, an individualised dosage adjustment was recommended for each patient. The contribution of the therapeutic drug monitoring programme to improving seizure control was evaluated. Dosage predictions using the Bayesian feedback approach and one serum concentration were compared with predictions determined using selected population parameters for children and no feedback. There was no difference for sodium valproate and phenytoin but a difference at the 10% level was found for phenobarbitone and carbamazepine. Thus while doses of sodium valproate in this population can be predicted effectively using certain published pharmacokinetic parameters, more accurate dosage predictions for carbamazepine and phenobarbitone will be achieved once appropriate parameters have been generated. Despite the apparent accuracy of phenytoin predictions, individualised dosage adjustments using Bayesian forecasting were found to be essential in the 29% of patients who were receiving phenytoin because of large inter-patient variation. Overall the therapeutic drug monitoring programme contributed to better seizure control in 56% of the patients entered into the study. Department of Clinical and Experimental Pharmacology, UniversiZy of Natal Medical School, P.O. Box 17039 Congella, Durban, South Africa.

OP 24.01

OP 24.03

INTERLABORATORY VARIABILITY IN THE DETERMINATION OF SERUM DRUG LEVELS: A REGIONAL COLLABORATIVE PROSPECTIVE STUDY E. Perucca, N. Barzaghi, G. Gatti, G.L. Visconti,L. Leone, R. Riva, G. Furlan, M. Snidero,.M.V. Perlangeli, D. Croci, A. Nespolo, R. Pagni, L. Robba, M. Bonati and G. Tognoni In recent years there has been an increasing awareness of the need for quality control (QC) in therapeutic drug monitoring, and many laboratories now participate in QC schemes. It has been suggested, however, that reliability in measuring spiked QC material may not reflect accurately performanoe with routinary samples. To evaluate this, 64 laboratories in the Lombardy Region of Italy accepted to participate in a QC program which involves, besides measurement of spiked samples, the re-analysls by 2-4 referer~e laboratories of patient samples randomly selected among those assayed routinely for phenytoin (PHT), theophylline (TEe) or digoxin {DIG) by each participating centre. The assay methods most widely used(FPIA and EMIT) were also used by the reference laboratories. Data available so far include 1OO7 values for the 3 drugs on 27 spiked samples and 2580 values (562 for PHT, 820 for TEe, 1198 for DIG) on 940 routinary samples. CVs for spiked samples containing concentrations within the most clinically relevant ranges ranged from 7 to 16% for PHT and TEe and from ii to 21% for DIG. For PHT and TEe, there was a good agreement between results Obtained by reference laboratories (reference results = RR) on routinary samples as well as between the means of RR and the original routinary values (r=O.98 and 0.95 for PHT and TEe respectively, slopes and intercepts not significantly different from identity). Fcm DIG, correlations between RR and between the means of RR and the original values (r=O.93 and 0.92 respectively, slopes and intercepts not significantly different from identity) were less satisfactory. These data indicate that the two approaches to assess analytical variability (distribution of QC samples and re-analysis of routinary samples) yielded similar results. Department of Medical Pharmacology, University of Pavia, Piazza Botta 10, 271OO Pavia, Italy

RAPID'ANTICONVULSANT ASSAYS AS PART OF CONSULTATION IN A PAEDIATRIC EPILEPSY CLINIC: A STUDY ON THE USE OF DRUGS P. N. Houtman, S. K. Hall, and G. W. Rylance The relevance of providing a rapid anticonvulsant monitoring service was assessed over a five-year period at a paediatric epilepsy outpatient clinic. A total of aSl drug assays were performed on la4 patients when considered clinically indicated. Drugs most frequently assayed were carbamazepine and sodium valproate, singly or in combination. 90% of assays performed for phenytoin (n=47) were from patients who were also taking other anticonvulsants. There were only six assays for ethosuximide and ten for phenobarbitone. There was a significant relationship between weightrelated dose and plasma concentration of earbamazepine (r=O.46;p
A 79

OP 24.04

OP 24.06

POPULATION PARAMETERESTIMATES (PPE) OF GENTAMIClN (G): BAYESIAN FORECASTING (BF) OF ICU CRITICAL CARE PATIENTS K. Rodvold~ R. Pryka~ R. Blum~ P. Kuehl~ P. Donahue I n i t i a l dosage regimens and subsequent BF is dependent upon PPE and the measurement of G concentrations (GCp). This study evaluated the p r e d i c t i v e performance of three sets ( I , I I , I I I ) of PPE: [ I ] t r a d i t i o n a l values, volume of d i s t r i b u t i o n (V)=0.25 L/kg and slope (CLs) of G clearance vs CRCI=0,815 ml/min/kg; [ I I ] l i t e r a t u r e PPE for ICU patients, V=0.35 L/kg and CLs=I.2 ml/min/kg; [ I I I ] calculated (Sawchuk-Zaske) PPE from 4-8 serial GCp of 15 ICU patients, V=0.45 L/kg and CLs=I.2 ml/min/kg. A l-compartment B forecaster, using the above PPE and feedback peak and trough GCp obtained on days (D) i , 5 and 9 of therapy, was then tested in 15 additional ICU patients. Mean (-+SD) prediction error (ME), mean absolute error (MAE) and root mean squared error (RMSE) using PPE with (F8) and without (WF) GCp feedback were: TROUGH GCp PP___~E PEAK GCp RMSE ME MAE RMSE Z ME MAE 0.5-+0.9 0.8-+0.6 0.94 WF 3.0-+1.1 3.0-+i.1 3.22 DIFB 0.5-+0.8 0.8-+0.6 0.97 -0.3-*0.5 0.5-+0.3 0.57 DI&5FB -0.3-+1.5 1.1-+1.1 1.50 -0.3-+0.7 0.6-+0.5 0.81 II 0.98 -0.4-+0.6 0.6-+0.4 0.77 WF 0.3-+1.0 0.8• DIFB 0.0-+0.8 0.7-+0.3 0.76 -0.4-+0.5 0.5-+0.3 0.61 DI&5FB -0.6-+1.4 1.1-+1.0 1.45 -0.4-+0.7 0.6-+0.5 0,81 III WF -0.3• 0.8-+0.5 0.97 -0.3-+0.7 0.6-+0.5 0.78 DIFB -0.2-+0.8 0.7-+0.4 0.77 -0.4+0.4 0.5-+0.3 0.61 1.51 -0.4-+0.8 0.7-+0.5 0.83 DI&5FB -0.8-+1.3 1.2• PPE II and I I I with 4 serial GCp on D1 and D5 did not s i g n i f i c a n t l y improve predictive performance. We conclude that: 1) G loading doses can be accurately i n d i v i d u a l i z e d by using PPE r e f l e c t i n g ICU patients; 2) BF can precisely predict maintenance doses from peak and trough GCp; and 3) the addition of serial GCp did not contribute to the precision of BF in ICU patients. University of I l l i n o i s m/c 886, Chicago, IL 60612 USA

PLARMA CONCENTRATION-TIME CURVES OF CYCLOSPOPJ~ IN PATIENTS U~ERGOING TRANSPLANTATION M.B.~egazzi, R.Rondanelli, L.Gastal~di: P.Villani. During the first three weeks after trarsplantation at the 6th and 21th day, ~e determined the AUC of cyclosporine (12 hours) ncn specifically by fluorescence polarization immmoassay (FPIA) and specifically by high performance liquid ~ t e g r a p b y (HPLC), after an oral dose of cyclcsporine in 12 patients undergoing heart iransplantation (HT). ~LC. No difference (p 0.05) was observed between elimination half-life (t 1/2) and clearance (CI/F) values obtained by FPLC an the 6th day(mean/ median: t 1/2 = 3.2/3.3 h; CI/F = 276.5/247.4 l/h;) and 21th day (mean/ median: t 1/2 = 2.2/2.3 h; CI/F = 268.9/177.6 l/h;). The CsA plasma le~ vels during a dosing interval were poorly correlated to the correspcndent AUC values. During a dosing interval the ratio between oroas-reacting metabolites and CsA was highest at lower concentrations (at 59.4 rg/ml:A.8; at 207.1 ng/mh8.2). The AUC values (1530/1281 ng.h/inl), associated to endonyocardial biopsy ( ~ ) proved episodes of mild, moderate and acute rejectian (+) were not significantly different frc~ the AUC values (1196/ 1179 rg.h/ml) found in pstients with negative ~ chri~g all the 21 days. FPIA. A gcod correlation was observed between CsA plasma levels measured by FPIA and corresponding AUC values. As for ~ L C data, the CsA level measured 6 hours after dose administration was of greater predictive value for the corresponding AUC, than was CsA level measured at other sampling times. The AUC values associated to positive ~ s (3776/3067 ng.h/ ml) were lower than those observed in patients with negative ~4Bs (6166/ 6260 ng.h/ml) during all the 21 days of study. In ocnolusion: a) by ~ L C assay the trough CsA level was not correlated to AUC value ; b) for therapeutic monitoring of CsA plasma levels, it is more reasonable to assess CsA levels 6 hours after drug ad~inistratian,by both FPIA and ~LC; c) since CsA metsbolites seem to provide a further refinement to CsA concentra%icns, the role of non specific assay (FPIA) during the first weeks after hT should be revaluated. Department of ~ c o l o ~ l , IRCCB, Policlinico S. Y~tteo,27100, PAVIA'

OP 24.05

OP 24.07

Withdrawn

PROSPECTIVES FOR THERAPEUTIC DRUGMONITORING IN ORAL MAINTENANCE THERAPY WITH 6-MERCAPTOPURINEIN CHILDREN WITH ACUTE LYMPHOBLASTIC LEUKEMIA. P. L a f o l i e , S. Hayder, O. Bj~rk and C. Peterson. Children with acute lymphoblastic'leukemia '(ALL} are given a long-term remission maintenance therapy with oral 6-mercaptopurine (6-MP) d a i l y and methotrexate weekly. Despite this treatment, 40% relapse. We have followed 22 patients with AlL during several years with repeated analyses of plasma 6-MP concentrations (mean 7) a f t e r intake of the drug on an emty stomach. Plasma samples were obtained before and 0.5-I.0-2.0-3.0 and 4 hours a f t e r drug intake. The area under the plasma concentration versus time curve (AUC) have been calculated with the trapezoidal rule. There were great i n t e r - and i n t r a - i n d i v i d u a l v a r i a t i o n s . Nine of the patients developed complications: two relapsed in the bone marrow, three patients relapsed in the central nervous system and four showed severe bone marrow t o x i c i t y . In children with relapse the mean AUC was 166.4 ng/ml x h, in Children with t o x i c i t y the mean AUC was 48!.8 ng/m! x h and the mean AUC in childrcn with no event was 315.5. All patients with an AUC between 200-400 ng/ml x h were free of events. Our results indicate that patients with suboptimal plasma drug levels may have an increased r i s k f o r relapse and that some patients are susceptible to develop drug t o x i c i t y . We conclude that this retrospective study indicates the p o s s i b i l i t y of a therapeutic interval and that this must be further evaluated in a prospective study.Dep~s of Clinical Pharmacology and Pediatric Oncology, Karolinska Hospital, S-I04 01, Stockholm, Sweden.

A 80

OP 24.08

OP 25.02

INDIVIDUALIZATION OF DOSE OF ACETYLSALICYLIC ACID IN R H E U M A T O I D ARTHRITIS PATIENTS. U. G u p t a , S. Kulshrestha. B.Singh. R. Verma. K . C . G a r g V.L. Mehta.

PHARMACOKINETICS, BIOAVAILABILITY, METABOLISM AND ACUTE AND CHRONIC ANTIHYPERTENSIVE EFFECTS OF NITRENDIPINE IN PATIENTS WITH CHRONIC RENAL FAILURE AND MODERATE TO SEVERE HYPERTENSION C. Machleidt, G. Mikus, V. Mast, U. Kuhlmann, M. Eichelbaum

Salicylates follow zero order kinetics at higher doses. A small increase in the dose m a y result in disproportionate inrease in its plasma concentration. Optimum plasm a concentration of 150 to 300 ng/ml is just below the toxic concentration and there is a need for individualization of the dose in patients of rheumatoid arthritis. Therapeutic drug monitoring has been carried out in 8 patients of rheumatoid arthritis. Acetylsalicylic acid. 60 mg/kg/day was given in divided doses for 7 days. On 8th day steady state concentration of salicylates was measured by obtaining blood samples 2 hrs. after first dose. In case of inadequate therapeutic response and low plasma concentration an increment of 5mg/kg/day on alternate d a y was made . Maximum dose did not exceed 75 mg/kg/day which resulted in an increase in plasma concentration (269-+47.8 ~/@/ml) in all patients. Clinical parameters, pain. morning stiffness, joint circumference and hand grip strength were recorded at each visit and response correlated with plasma concentration. 75% patients (n=6] achieved plasma concentration within the therapeutic range (175.11-+10.4 mg/ml) with 60 mg/kg/ day dose. The improvement in clinical parameter was dose dependent and could be correlated with plasma concentration. In 2 patients despite achieving maximum therapeutic concentration (308 ~g/ml and 300 mg/ml) only mild improvement w a s observed. Department of Pharmacology,Maulana Azad Medical College. N e w Delhi-ll0 002. INDIA.

The pharmacokinetics, hloavagability and antihypettensive effects of nitrendipine were studied in twelve patients with impaired renal function and moderate to severe hypertension. Creatinine clearances of these patients were below 50 ml/min, 7 patients were on continuous ambulatory peritoneal dialysis (CAPD). A stable isotope technique was used which allows for the simultaneous i.v. and p.o. administration of the drug. Following i.v. administration no significant differences could he observed in systemic clearance in the patients as compared to healthy volunteers (16.2 • 6.1 vs 18.6 • 3.6 ml/min/kg). The slight increase in elimination half life in patients (10.4 h vs 8.6 h) was solely due to an increase in the volume of distribution (Vss: 9.3 +-3.4 vs 5.4 • 2.4 I/kg). Cumulative urinary excretion of nitrendipine metabolites was correlated with the creatinine clearance (r = 0.946, p < 0.001 ). in patients on CAPD less than 0 . 0 1 % of the nitrendipine dose was found in the dialysate during the first 6 h after drug administration . Thus, the dialysate clearance was extremely low (on average < 10 ml/h). A significant reduction in mean arterial blood pressure (mean: 23.6 %) at the end of the nitrendipine infusion and after oral administration of 20 mg (mean: 17.5 %) was observed. During a 4 week therapy on average 62 mg nttrendipine per day was necessary to achieve a systolic blood pressure below 160 mm Hg or a diastolic blood pressure below 90 mm Hg. There was a significant relationship between the nitrendipine bicavailability and the dose required for sufficient blood pressure control. No accumulation of nitrendipine was observed during this 4 week therapy. Thus, no adjustment of nitrendipine dose is required in patients with renal fai|ure. Supported by the Robert Bosch Foundation, Stuttgart. Zentrum Innere Medizin - Abteilung Nephrologie, Robert-BoschKrankenhaus, Auerbachstr.110, 7000 Stuttgart 50

OP 25.03

OP 25.01 PATHOPHYSIOLOGICAL CLEARANCE

~0DEL

OF R E N A L

DRUG

I. J a n k d A m o d e l of r e n a l d r u g c l e a r a n c e a c c o u n t i n g f o r c h a n g e s i n the f u n c t i o n a l c a p a c i t y of the k i d n e y u n d e r p a t h o l o g i c a l c o n d i t i o n s is p r e sented. I n a g r e e m e n t w i t h the m o r p h o l o g i c a l a r r a n g e m e n t of b l o o d s u p p l y of the n e p h r o n the m o d e l r e f l e c t s s e r i a l o r d e r i n g of the p r o c e s s e s c o n t r i b u t i n g to r e n a l d r u g e x c r e t i o n . ~ o r e o v e r , t u b u l a r s e c r e t i o n is a s s u m e d to be l i m i t e d by r a t e s of p l a s m a f l o w in the p e r i t u b u l a r c a p i l a r i e s a s w e l l as of f i l t r a t e f l o w i n t h e tubuli. A d d i t i o n a l p a r a m e t e r s of the m o d e l a r e the f i l t r a t i o n f r a c t i o n a n d the f r a c t i o n of the d r u g r e a b s o r b e d i n the t u b u l i . The m o d e l p r e d i c t s l i n e a r d e p e n d e n c e of r e n a l drug clearance on glomerular filtration rate and s c o n s t a n t e x c r e t i o n f r a c t i o n o n l y f o r drugs exe~e~e~ ex~l~si~e~y by fil~e~i~n in the g l o m e r u l i . F o r d r u g s e x c r e t e d a l s o b y tub u l a r s e c r e t i o n the r e l a t i o n s h i p b e t w e e n r e n a l drug clearance and glomerular filtration rate is c u r v i l i n e a r a n d the e x c r e t i o n f r a c t i o n r i ses w i t h d e c r e a s i n g r a t e of g l o m e r u l a r f i l t r a tion. S u c h b e h a v i o u r is c o n s i s t e n t w i t h p u b l i shed date o n r e n a l c l e a r a n c e of c o m p o u n d s exc r e t e d b y t u b u l a r s e c r e t i o n (PAH, u r i c s o l d ) a n d t h e i r r e l a t i o n to c h a n g e s i n g l o m e r u l a r filtration rate. I n s t i t u t e of P h a r m a c o l o g y , C z e c h o s l o v a k A c a d e 9 Y of S c i e n c e s , A l b e r t o v 4, 128 0 0 P r a g u e 2, CSSR

DEPRESSOR EFFECTS AND PHARMACOKINETICS OF SINGLE AND CONSECUTIVE DOSES OF DELAPRIL IN HYPERTENSIVES WITH NORMAL AND IMPAIRED RENAL FUNCTION. K. Minamisawa, H. Shionoiri., K. Suqimoto, K, Ashino, K. Bbina r Y. Tokita r E. Gotoh. and M. Ishii. The depressor effects and pharmacokinetics(PK) of delapril (DL), an ACE inhibitor, were investigated in hypertensives (HT) with normal renal fiknction(NRF}n=6) and impaired renal function(IRF;n=5). A 15mg oral dose of DL was given once on the day 1st and last, twice daily on the other 6. Blood pressure(BP) was measured at 0, l, 2, 4 , 6 , 12 & 24h post-DL on the day Ist and last, to be compared with BP of a placebo study. Blood sampling was done at 0, i, 2, 4, 6, 12 & 24h post-DL to observe ACE activity and PK of DL and its active metabolites(aL diaeid;DLA, 5-hydroxy-DLA;" 50HDLA). Plasma DL, DLA and 5OHDLA were measured by HPLC. DL was well tolerated by.all patients, and no side effects were observed. In consecutive dose, significant BP falls were found from lh post-DL to 24h in NRF and to 6h in IRF. ACE activities were suppressed from lh after the ist dose to 24h after the last in both NRF and IRF. PK parameters of DL, DLA and 5OHDLA are shown in the following table. Cmax(n@/ml) Tmax(h) tl/2(h) AUC(ng.h/ml) NRF IRF NRF IRF NRF IRF NRF IRF *p~.05 First 121 119 1.0 1.0 209 146 DL Last 126 103 1.2 1.0 152 241 First 377 477 1.2 1.0 1.2 2.3 918 2111" DLA Last 386 493 1.2 1.2 1.7 3.2 980 2259 First 170 281" 2.6 1.5 1.8 3.2 477 I~36" 5OHDLA Last 192 378* 2.2 1.6 6.2 22.7 1049 3648 NO significant increase of PK parameters in repeated dose was observed in NRF and IR~. Significant positive correlations were found between i/Ccr and AUCs of DLA and 50}{DLA in single and consecutive doses. In conclusion, since BP was not well controlled in IRF, probably volume dependent HT, despite of full suppression of ACE activity and of significant enlarging of AUC, a concomitant use of a small amount of diuretics with DL should be suggested. 2nd Dept of Internal Medicine, Yokohama City Univ., 3-46 Urafune-cho, Minami-ku, Yokohama 232, Japan

A 81

OP 25.04

OP 25.06

ANTIHYPERTENSIVE EFFECTS AND PHARMACOKINETICS OF SINGLE AND CONSECUTIVE DOSES OF LISINOPRIL IN HYPERTENSIVE PATIENTS WITH NORMAL OR IMPAIRED RENAL FUNCTION H. SHIONOIRI~ K. SUGIMOTO~ T. MIYAKAWA~ K. EBINA~ K. MINAMIZAWA, Y. ABE~ S. UEDA, N. SAKAGI, E. GOTOH~ AND M. ISHII

PHARMACOKINETICS OF CADRALAZINE AND ITS HYDRAZINO METABOLITE IN RENAL IMPAIRMENT. P.C. BRUNEL*, J.F. MARICHAL**, J.B. LECAILLON*, J. MENARD*

The antihypertensive effects and pharmaeokinetic properties of lisinopril, a long-acting angiotensin converting enzyme (ACE) inhibitor, were investigated in hypertensive patients with normal renal function (NRF; n=9) and those With impaired renal function (IRF; n=8). A I0 mg dose of lisinopril was administered orally once a day for 5 or 8 days~ Measurement of blood pressure and sampling of blood specimens were done on the first and last days of treatment. Lisinopril induced significant falls in systolic and diastolic blood pressures as early as 2h after administration. The antihypertensive effects were still observed at 24h postdose. Serum ACE ~ctJv~ty was markedly suppressed over 24h, with the enzyme inhibition greater in the IRF group. Plasma levels of lisinopril in the IRF group were higher than those in the NRF group, with significant differences in the peak levels and areas under the plasma concentration - time curve (AUC). A significant inverse correlation was found between the creatinine clearance and the AUC for lisinopril. Lisinopril was well tolerated by all the patients, and no adverse reactions were observed. These results suggest that lisinopril has a longlasting action and that it is a useful antihypertensive agent for controlling blood pressure in patients with either NRF or IRF at once daily administration. SECOND DEPARTMENT OF INTERNAL MEDICINE, YOKOHAMA CITY UNIVERSITY, SCHOOL OF MEDICINE, YOKOHAMA 232, JAPAN

Cadralazine (C) is a new antihypertensive drug, acting through its hydrazimo-pyridazine metabolite (M) as a peripheral arteriolar vasodilator. C is mostly eliminated from plasma in the unchanged form by the renal route (60-80% of the oral dose is recovered in the urines). Since M contributes to the activity of the drug, we investigated the pharmacokinetic patterns of C and M in 12 healthy volunteers (H) after a 10 mg oral dose and in 7 renally impaired patients (RI) after a 5 mg dose. The mean creatinine clearance was 26.3+11 ml/min.(19-37) in this latter group. C and M plasma levels were determined by HPLC. The results are reported in the following table: cadralazine Cmax Tmax TI/2 AUC a.f. nmol/l h h 0-24h H (10 mg) 680 I 2.4 1774 RI (5 mg) 395 I 6.7 3663 1.1 hydrazino-pyridazine metabolite Cmax Tmax TI/2 AUC a.f. nmol/l h h 0-24h H (10 mg) 6.9 I 23 RI (5 mg) 10.5 7 189 1.7 a.f.: accumulation factor = AUC (0-24h) day 9 / day I. No T I/2 was calculated for the metabolite (-). After one week, in renally impaired patients, the accumulation factor showed that M accumulated more than C. Therefore, considering these results and the fact that M is the main component in the antihypertensive effect of C, a reduction of the daily dose is necessary t o t a k e into account the pharmacokinetic of M and to avoid severe sideeffects in patients with renal impairment. * Pharma Research and Development. CIBA-GEIGY Limited, 4002 Postfach, Basel, SWITZERLAND. ** Louis Pasteur Hospital, 68021-Colmar, FRANCE.

OP 25.05 PHARMACOKINETICS FAILURE

OF~%K]~[IMONE IN P A T I E ~ S W f T H

OP 25.07 PEFLOXACIN PHARMACOKINETICS ~N CAPD PATIENTS 1 J.Varl~, A.Lenardis 2, A.Bren , g.Kopitar , A.Gu~ek , M.~or~ , J.Drinovec I

]~NK)-ST2~

P. Fie@el, H.A. Dieterich, E. J~hnchen and D. T r e n k The positive inotropic drug enoximone is almost completely metabolised and the main metabolite formed is enoximone sulfoxide. It has been shown in animal experiments that: (i) the metabolite still exerts approximately 20% of the pharmacological activity of the parent compound and (2) reconversion of the metabolite to enoximone is possible. Because enoximone sulfoxide is eliminated via the renal route, we investigated the pharmacokinetics of, enoximone following i.v.-bolus doses of 1 mg/kg bodyweight within the interval between two haemodialysis procedures in 5 male patients with end-stage renal failure. In the patients investigated, the total plasma clearance (CL) of enoximone was decreased (median: 0.41 i/min.) and the steady-state volume of distribution (Vss: 6.38 i/kg) was increased in comparison to the parameters obtained in healthy volunteers (CL=I.99 i/min.; vss=l.81 i/kg). These alterations lead to a marked increase in the terminal half-life of elimination of enoximone (22.05 vs. 0.95 hrs.). An impairment of the eliminiation is also obvious with respect to the pharmacokinetics of the formed metabolite enoximone sulfoxide. The half-life of elimination (40.53 vs. 2.24 hrs.) as well as the the ratio of the area under the plasma concentration-time curve (AUC) of the metabolite to the AUC of the parent compound (24.1 vs. 2.81) were markedly increased compared to the values obtained in healthy volunteers. These results suggest that the dose of enoximone should be reduced in patients with severely impaired renal function. Deutsche Klinik for Diagnostik, Auka~maallee, [3-6200 Wiesbaden, and Abteilung f~r Klinische Pharmakologie, Rehabilitationszentrum, S~dring 15, D-7812 Bad Krozingen

Pefloxacin(PE) pharmacokinetics was studied in four chronic stable CAPD patients without evidences of peritonitis. Each patient underwent 4 daily exchanges of 21ite~ of dialysate. Plasma,dialysate and urine PE concentrations were followed up to 24 hours after administration. The determination of PE were made by HPLC method. On the basis of experimental results pharmacokinetics parameters were calculated. Concentrations of PE in plasma and peritoneal effluent following 400 mg IV and IP dose is presented in fig.1 and fig.2 respectively.

101IV ;

..501 ~.2sj

P !

] 12

24 T(h}

Fig.1. PE levels after IV application P= plasma, D=dialysate

~~Dp~~.~.'mf f . . 12

2&T(h)

Fig.2. PE levels after IP application P=plasma, D= dialysate

Sequential therapy regimen with PE (i.e. 400 mg IV than 2 days 100 mg/liter IP and next 6 days 400 mg po bid)was used in 6 patients with proved bacterial peritonitis. Clinical results were very good in all patients.Kinetic studies have shown excellent bidirectional diffusion of p E through peritoneal membrane and therapeutically adequate concentrations of PE in plasma and peritoneal dialysate for most clinically important bacteria. Iuniversity Medical Center, Department of Nephrology, 261000 Ljubljana, Zalow 7, Yugoslavia Lek, Pharmaceutical and Chemical works Ljubljana

A 82

OP 26.01

OP 26.03

THE USE OF A COMMON CENTRIFUGAL ANALYZER FOR ESTIMATION OF PLATELET A G G R E G A T I O N Selfert. W.. Briihahn, Chr. and Buitrago. B. Centrifugal analyzers are common equipment in clinical chemistry, standing out for little consumption of reagents and sample material. Reproducibility of analyses between the position of one and the same rotor is excellent. Programmable systems such as the Multistat III by Instrumentation Laboratories allow for individual adaptation of the analytic procedure, in order to mimic the course of stirring and photometry of analog devices for aggregometry. The standard commercial rotor consists of at least 20 sample-places with an outer chamber for the aealyte (platelet rich plasma, PRP) a n a a n inner one for the reagent. Both chambers can be loaded automatically, thus reducing procedural variances by manual filling. Only 150 ul PRP per place are needed, the reagent size is 15 ul. Usual standards can be maintained: PRP is set to 200"10^3 platelets, aggregation reagent can be ADP in final amounts of 0.625 to 10"10^-6 real, suprarenin from 0.25 to 4"10^-6 mol, collagen from 1.25 to 20 ug, and thrombin from 0.2 to 0.3 IU. Depending on the loading,procedure other techniques as to pre-incubation routines are possible as welt. Thereby a homogeneous analysis for up to 19 samples at once with various reagent combinations can be carried out

E F F E C T S O~ T W O C A - A N T A G O N I S T S , D I L T I A Z E M A N D VERAPAMIL ON PLATELET AGGREGATION IN MAN S. H a s s a n a n d I m a n N a j i C a - a n t a g o n i s t s h a v e b e e n r e p o r t e d tob i n h i b i t p l a t e l e t a g g r e g a t i o n i n v i t r o ( A . G o t t a et al., Clin. P h a r m a c o l . Ther. 39, I95, I986) & i n v i v o (M. R i n g et al., Brit. J. clin. P h a r m a c . 24, 6 1 5 - 6 2 0 , I987) a l t h o u g h s o m e r e s e a r c h e r s detected these effects only afterrepeated d o s i n g s (C. J o n e s et al., Brit. J. olin. Pharm. 20, I 9 I - I 9 6 , I985) or w i t h h i g h c o n c e n t r a t i o n s (A. S h a w st al., H a e m o s t a s i s 50, 0If7, I983). The a i m of this w o r k w a s to i n v e s t i g s t e the e f f e c t s of a s i n g l e o r a l d o s e of e i t h e r d i l t i a z e m or v e r a p a m i l on p l a t e l e t a g g r e g a t i o n . The studies were double-bllnd, placebo-controll e d , , c r o s s o v e r & r a n d o m i z e d . D i l t i a z e m (60 mg) & v e r a p a m i l (40 mg) w e r e i n v e s t i g a t e d , e a c h i n 6 healthy, drug-free & non-smoker volunteers. P l a t e l e t a g g r e g a t i o n r e s p o n s e s to c o l l a g e n were determined before & 3 & 2 hours after diltiazem & verapamil respectively. Increasing c o n c e n t r a t i o n s of c o l l a g e n ( 0 . 4 - I 2 . 5 m g / m l final concentrations) were used & percentages of l i g h t t r a n s m i s s i o n w e r e r e c o r d e d . R e s u l t s s h o w e d a s h i f t of the d o s e - r e s p o n s e c u r v e s to the r i g h t f o l l o w i n g b o t h d i l t i a z e m & verapamil treatments compared with placebo. ANOVA-test revealed a significant inhibition of p l a t e l e t a g g r e g a t i o n r e s p o n s e s f o l l o w i n g diltiazem & verapamil treatments compared with placebo (P
The reaction is started with a fast rotor-acceleration to 4000 rpm, iramediately afterwardsstoppedfor mixing reagent and PRP. During the following 7.5 minutes the rotor turns with 600 rpm, interrupted by stops at each 3 second interval. Data are Obtained every 10 seconds and transmitted electronically to a custom data management system. The resulting aggregation curves resemble much those provided by analog devices, the coefficient of variation within one rotor being 16.14 for 1.25"10^-6 mol A D P and 4.00, 1.35, 1.49 and 1.74 for 2.5, 5, 10 and 20"10^-6 real ADP. The system however is far superior by the reduced amount of PRP and the possibility to analyse simultaneously a bigger number of samples.

Platelet-Aggregati0nwith M3

~ * n i ~~" ~k ~ 200

k~ k~ ~t

~1

100-

i~ ~ 00

o

Inhibiti0nwith~PROST

~ 0~ -~=

~-"

~_ ~-

0 0.6 1.25 2.5

5 l0 20 40 80 m01ADP*10"-6

The estimation of platelet aggregation in research and development is greatly facilitated. Humanpharmakologie I, Schering AG, MiillerstraBe 172, 1000 Berlin 65

OP 26.02

OP 26.04

THE EFFECTS OF DIPYRIDAMOLE AND OTHER ANTI-PLATELET

PHARMACODYNAMICS AND TOLERANCE OF A THROMBOXANE A2-SYNTHETASE INHIBITOR (CV ~151) IN CAUCASIAN SUBJECTS G. Strauch, A. Kahan, S. Weber, J. Barr@, 0. Reigneau, P. Chr&tien, D. de Lauture, M. Letrait, J.M. Husson, J.P. Tillement. A thromboxane A2 (TXA2) synthetase inhibitor (CV 4151, Takeda Ltd Japan) was administered orally to 54 healthy male caucasian subjects as 9 incremental single doses ranging from i0 to 400 mg, At each dose level 4 subjects received the active drug and 2 a placebo in a double blind randomized design. In addition to standard clinical and biological parameters we assessed the pharmacodynamics and pharmacokinetics of the compound. Thromboxane B2 (TXB2), the major TXA 2 metabolite, and 6 keto POFIa, were assayed in serum for 7 days post-dose. The drug and 3 metabolites were measuredin plasma for 24 h post-dose. TXB 2 levels were dramatically suppressed at doses as low as i00 mg. Higher doses only increased the inhibition duration for at least 24 h. A positive dose-related effect on the peak 6 keto PgFlalevel, saturated before the 400 mg dose level, was demonstrated. Although the study was not designed to point this out, a statistically significant (r=0.97 p<0.0001), nearly linear relationship between the area under the curve and the dose was shown. The elimination half-life was 1.03 i 0.27 h (range 0.62 2.17 h). No relevant clinical and biological abnormalities occurred during the study. Since the pharmacodynamic effect duration was not related to the apparent elimination half-life, a 50 to I00 mg once a day dose might be sufficient to obtain a clinical effect. IRT-ECLIMED - H6pital Cochin 75014 PARIS and Laboratoire de Pharmacologic CRETEIL FRANCE.

DRUGS ON PDGF RELEASE FROM PLATELETS K. Takehara, A. Igarashi, and Y. Ishibashi Previously we have shown that dipyridamole decreases platelet-derived growth factor (PDGF) levels in human serum through inhibiting PDGF release from platelets (Arteriosclerosis

7:152-158, 1987). In

the present study, we compared the effects of various anti-platelet drugs on inhibitory action for PDGF release from platelets. Two normal volunteers took normal dosage of each drug for 3 days and we obtained sera. PDGP-related activities were measured by a biological assay using normal skin fibroblasts. Our investigation revealed that dipyridamole specifically decreased PDGF levels in human serum; neither of aspirin, trapidil nor tyclopidine affected PDGF levels. Additional experiment showed that dipyridamele inhibited PDGF release from platelets but did not inhibit the release of other platelet factors such as 8-thromboglobulin or platelet factor IV which were stored in ~ granules. Our data suggested that dipyridamole might be an effective drug to prevent fibrotic diseases in which PDGF played a major role. Dep. of Dermatology, Univ. of Tokyo, Branch Hosp. 3-28-6, Mejirodai, Bunkyo-Ku, Tokyo 113, JAPAN

A 83

OP 26.05

OP 26.07

INTERACTION STUDY BE'fWEEN A NEW T H R O M B O X A N E ANTAGONIST (GR32191) AND HEPARIN IN SIX HEALTHY M A L E VOLUNTEERS. A. de Boer. J.M. Kroon. A. van Vliet. D.D.Breimer. S.Donoghue and A.F. Cohen GR32191 is a specific thromboxane receptor blocking drug developed for the prophylaxis of thromboembolic diseases. GR32191 can be expected to be useful for the prevention of reocclusion after thrombolysis for myocardial infarction and concomitant use with heparin for this indication can be anticipated. We studied possible pharmacokinetic and pharmacodynamic interactions between GR32191 and hepadn in healthy volunteers. The study was a double-blind, random}sed, placebo-control}ed, cross-over trial in six healthy male volunteers. Treatments administered at weekly intervals were a) an iv infusion of heparin (5000 IU bolus + 1000 IU/h for 3 h) (HEP) and GR32191 (40 rag) orally (GR), b) an iv saline infusion with oral GR and c) HEP with placebo GR tablets. HEP disposition was determined by means of plasma anti-Xa and antithrombin activities and pharmacokinetic parameters of GR were calculated. The effects on haemostasis were determined by APTT, collagen and U46619 induced platelet aggregation and bleeding time. The pharmacokinetics of GR and HEP were unchanged during coadministration of both drugs. GR did not influence the effects of HEP on the APTT nor did HEP affect the effects nf GR on plat~l~t aggregation All tre~tm~nt~ produced a prolongation of the bleeding time compared to screening values. The mean increase after HEP alone was 2.8 min, after GR alone 6.4 rain and after HEP + GR 10.5 min. During HEP + GR the bleeding time (16.3+ 3.9) was significantly loungerthan during GR alone (12.1 + 3.7) and HEP alone (8.4+ 1.0) (p<0.05i. This interaction between both drugs appeared additive. Pharmacokinetics of HEP and GR and individual effects of the drugs on secondary and primary haemostasis respectively were unchanged by the combination HEP + GR. However, an increase in bleeding time occurs after the combination. Centre for Human Drug Research, P.O. BOX 9600, 2300 RC Leiden, The Netherlands.

A PROSPECTIVE STUDY OF COMPLIANCE IN PATIENTS STARTING WARFARIN THERAPY S. Kumar, S: Peaks?, J.A. Davies, B.E, Roberts, M. F e e l y Poor compliance with prescribed warfarin appears to be a major cause of unstable ankicoagulafion (Kumar et al, Br. J. elin. Pharmac. 26, 620P, 1988). We have prospectively investigated the extent of this problem in 62 patients (56 males, 26 females; aged 18 to 78 years), starting on either short or long term warfarin therapy. Patients were given capsules containing their total daily dose of warfarin and 2 mg phenobsrbitone (PB); fhe latter as a pharmacological indicator of compliance. The dose of PB used is neither sedative nor enzyme inducing (Feely et al, Br. J. clin. Pharmac. 24, 77, 1987). They were reviewed at consecutive clinic visits for a period of I to 9 months (>I to 3mths, n=20; >5 s 6mths, n=21; >6 to 9mfhs, n=21). PTasma PB levels were measured at regular infervals and at any visit when the International Normalised Ratio (INR) was outside the therapeutic range of 2.0-4.5. PB level to dose ratios (LDRs) were then calculated and compared to 'expected ranges' derived from previously studied age matched volunteers (Feely et al, 1987). The tab]e shows the percentage of clinic visits at different ranges of 1NR (*total number of visits shown in parentheses). INR >1 t o 5mths >3 t o 6mths >6 t o 9mths -- (48)* (86)* (141)* <2.0 13% 16% 26% 2.0-4.5 83% 79% 70% >4.5 4% 5% 4% Steady-state PB LDRs <95~ of the lowest volunteer value were found in 23% of all visits when the INR was <2.0 (17% in >I to 5mths; 29% in >3 to 6mths; 24% in >6 to 9mfhs) and--in only I visit when the INR was 2.0-4.5. In 4 of 12 visits when the INR was >4.5i PB LDRs suggested that excess doses may have been taken shortly before visits. Thus, poor compliance with warfarin is an important contributory factor in unstable anticoagu]ant control. Clinical Pharmacology Unit and Department of Haematology, The General Infirmary, Leeds LSI SEX, UK.

OP 26.06

OP 26.08

THE BIOCHEMISTRY OF THE STEREOSELECTIVE 4-HYDROXYCOUMARIN ACTION H.H.W. Thljssenf H.T.M. Vervoort-Peters, and L.G.M. Bears The 4-hydroxycoumarin anticoagulants are racemlc mlxtures. Pharmacodynamic evaluations in men and rats showed the Senantiomers to be more potent (2-5-fold) than the R-enantiomers. These differences in potency are not due to pharmacokinetic differences. The target of the 4-hydroxycoumarin compounds is believed to the the hepatic microsomal enzyme vitamin K 2,3-epoxide reductase. Own observations and those of others, however, showed no differences in the sensitivity of vitamin K 2,3-epoxide reductase for the Rand S-enantiomers in in-vltro a~ays. We performed in-vlvo and ex-vivo studies with H / S - [ C] warfarin to elucidate the principle of the stereoselectivlty of the 4-hydroxycoumarins. The i.v. administration of S-warfarin (I mg{~g) to rats that were loaded wi{~ "microdoses" of R/S[=~C] warfarin 48 before showed R-[ C] warfarin to be displ~ed from its hepatic binding site 4 times as fast as S-[ = C] warfarin. T~ratlon of the microsomal warfarin binding sites with ~ C-warfarln showed no differences ~or R- and S-warfarln. However, microsomes prepared from C-warfarin treated rats when treated with dithiothreitol (i0 mM) released more R-warfarin than S-warfarin in time. Hicrosomal vitamin K 2,3-epoxide reductase activity at dithlotbreitol concentrations maximal for control reaction (i.e. [DTT] 2 mM) showed no difference for R- and S-warfarln in reaction rate. At higher reductor concentrations (>i0 mM), however, the reductase activity was higher for R- than for S- warfarin. These results suggest the following mechanism to operate: vitamin K 2,3-epoxide reductase in its oxidized (= inactive) form binds equally the R- and S-enantiomer of 4-hydroxycoumarins. The attached coumarin retards the reduction (= reactivation) of the enzyme. This effect is more pronounced for the S-configuration. Dept. of Pharmacology, University of Limburg, P.O. Box 616, 6200 MD Maastricht, The Netherlands

PROTAMINE S U L F A T E AND P R O T A M I N E CHLORIDE IN PATIENTS UNDERGOING CARDIAC

SURGERY A. Kuitunen, M. Salmenper/i, J. Heinonen, V. Rasi and G. Mvllvl/i Protamine chloride is more stable in human plasma in vitro than protamine sulfate and may also undergo slower elimination in patients.Thus protamine chlor/de is presumed to be a better antidote to heparin after cardiac surgery than protamine sulfate. 30 cardiac surgery patients were studied. Initial heparin dose for cardiopulmonary bypass was determined by constructing heparin dose -activated clotting time response curve. Heparin was neutralized either by protamine sulfate or protam/ne chloride. The total heparin to protamine dose ratios were 0.71_+,05 for sulfate and 0.77_+.07 (rag/100 U) for chloride. The initial neutralizations, the subsequent behavior of heparin plasma levels and coagulations parameters did not differ between the groups. After n e u t r a l i z a t i o n p l a s m a h e p a r i n levels i n c r e a s e d significantly in both groups peaking at two hours after protamine. The postoperative blood losses were comparable in both groups. The two protamine salts are equally effective antidotes to heparin after cardiac surgery. The low rebound plasma heparin levels might be innocent in terms of blood loss. Department of Anaesthesia, Helsinki University Central Hospital and Finnish Red Cross Blood Transfusion Service, Haartmaninkatu 4, SF-00290 Helsinki, Finland

A 84

OP 27.01

OP 27.03

PHARMACOKINETICS OF CEFPIRDME IN PATIENTS WITH RENAL IMPAIRMENT B. Rosenkranz, N.H. Lameire and V. Malerczyk Cefpireme (HR 810) is a new cephalosporin d e r i v a t i v e which is active against a broad range of b a c t e r i a l strains. Dosages of 2 g b . i . d , are safe and well t o l e r a t e d . The drug is eliminated almost exclusively by the kidneys ( t o t a l clearance, CL, about 160 ml/min; renal clearance, CL~, about 130 ml/min; terminal h a l f - l i f e , t l / 2 , about 1.8 hrs. in healthy subjects). The aim of the pre~ent investigation was to assess the influence of renal impairment on the pharmacokinetics of cefpirome. 22 patients (16 F/6 M; age 30-79 years; creatinine clearance, CL , 4-86 ml/min) participated in the study. Each patient r ~ e i v e d a single i.v.-dose of 2 g cefpirome; urine and blood were collected once before and at regular i n t e r v a l s up to 96 hours a f t e r administration. Concentrations of cefpirome (HPLC) and creatinine (enZymatic method) throughout the study were determined. The patients were grouped before the study according to creatinine clearance (CL r ) , and adjustments according to CL values during the s~udy were made a f t e r cr. wards. The follew:ng pharmacokinetic characteristics (volume of d i s t r i b u t i o n at steady state, V ))were calculated using a 2-compartment model (mean, S%. : OROUP N CLcr (ml/m|n) CL ~ t/ -.~, , (~.o.I (v,,.) .tl (trl ......................................................................... Control 10 normal 125.5 (15.5) 17.6 (3.0) 1.8 (0.2)

ENOXACIN DISPOSITION IN PATIENTS WITH CYSTIC

I II III

5 >80 4 20-50 6 10-20 7
6g.s (15.9) 30.4 (5.4) 11.1 (2.0) 5.6 (1.3)

I02.2 (30.S) 43.5 (3.8) ZZ.8 (8.5) 21.2 (15.0)

21.7 (3.4) 24.7 (6.6) 17.8 (S.l)

2.8 (0.0) 7.4 (2.4) 10.1 (4.0)

IV 22.6 (3.7) 15.0 (5.5) The data from 8 group of healthy subjects (control) are given f o r comparison. Terminal h a l f - l i f e increased with

the degree of renal impairment, and there was e l i n e a r rel a t i o n between CL__ and CL (CL = 0.83 x CL + 14.0). On . r the basis of thes~rfindings, a reductzon o~ the usual dosage to 50 % is recommended at GFR of 20-50 ml/min and a further reduction to 25 % at GFR of 5-20 ml/min. Department of Nephrology of the University of Ghent, De Pintelaan 185, B-9000 Ghent, Belgium

OP 27.02 PHARMACOKINETICS AND DRUG DISTRIBUTION OF FURBENICILLIN J.T. Li and X.J. Xu Furbenicillin is one of ureidopenicillins developed in China. A study on pharmacokinetics of furbenicillin was carried out in six healthy volunteers compared with piperacillin and carbeni@ cillln. Serum and urine samples were collected for antibiotic assay by using microbiological assay method. A comparative study on furbenicillin and carbenicillin were also performed in 14 dogs. The drug d i s t r i b u t i o n of furbenicillin in mice was studied by using microbiological and autoradiographic techniques. The results showed that the concentratlon/time curves of the three drugs fitted a two compartment open model after intravenous infusion of furbenicillin, piperacillin and carbenicillin, each of 1.0 g, w i t h equations C t = 6 8 . 1 2 e - 4 - 4 6 t + 27.17e-1.57t~ p~ = 38.48e-4.40t + 21.12e-O.86t, Ct = 17.09e -9"~ + 21.63e -0"89t, respectively. The mean peak serum level of furbenicillin was 87.03 mg/l, whleh was 2.1 and 1.7 times higher than" those of oarbenloillin and piperaeillin, respectively. The renal clearance of furbenicillin was m u c h lower than that of carbenioillin and also obviously lower than that of piperacillin, but total body clearance of the three drugs were similar. Similar results were also observed in dogs. The concentrations of furbenioillin in most tissues were higher than those of oarbenicillin within one hour after administration, especially in lung, liver and intestines. The possibility of the presence of an extrarenal clearance of f u r b e n i c i l l i n was discussed. Institute of Clinical Pharmacology, BeiJing Medical University, 8 Xi Shi Ku Street, Beijing 100034, People's Republic of China.

FIBROSIS (CF) AND HEALTHY CONTROL SUBJECTS M. Seine. Y. Bentur. S. Martin. H. Heurter. M. BrilI-Edwards. A. Tesoro. J. Correia. R.Poo. R. Gold. and S. MacLeod Enoxacin pharmacokinetics were examined in 14 subjects (8 healthy controls & 6 CF patients) in a study of prophylaxis of pulmonary exacerbations due to Pseudomonas aeruginosa in patients with CF.. Disposition after the first dose of 300 or 400 mg orally in CF patients (mean 6.0 mg/kg) was compared to control subjects (mean 5.4 mg/kg). Serum and urine were collected for 24 hours after the dose and assayed for enoxacin by HPLC. The mean age (27.1 vs 24.4 yr) and size (1.86 m 2 vs 1.71 m 2 ) were similar in control and CF subjects (p>0.2). No significant differences (mean + sd) in maximum (3.3 + 0.9 vs 3.9 + 1.2 i.tg/ml), or 24 hour (0.05 + 0.03 vs 0.07 + 0.03 ~tg/ml) serum enoxacin concentrations were found in control & CF subjects respectively. Nor was there any significant difference in the elimination rate constant determined by linear regression of the terminal phase (0.165 + 0.037 vs 0.141 _+0.022 h-l), the volume of distribution at steady state, cabulated by moment analysis uncorrected for absorption (2.24 +_0.84 vs 2.16 + 0.75 L/kg), total body clearance uncorrected for absorption (461 + 149 vs 413 + 196 ml/min/1173 m2), or renal clearance (277 + 172 vs 294 + 145 ml/min/1.73 m2) for controls vs CF respectively. Unlike most antibiotics which have lower serum concentrations and higher clearances in CF, the mean serum enoxacin concentrations and clearances were not significantly different from controls. Most studies indicate ciprofloxacin has similar kinetics in CF & controls as well, raising the possibility that the flouroquinolones, as a group might not exhibit altered kinetics in CF patients. If enoxacin is to be used in CF, these data suggest no dose adjustment may be necessary,

Divisions of Clinical Pharmacology & Infectious Diseases, Hospital For Sick Children, and Faculties of Pharmacy & Medicine, University of Toronto, 19 Russell St, Toronto, Canada, M5S 2S2

OP 27.04 IMIPENEM/CILASTATIN (IMP) IN INTENSIVE CARE UNIT (ICU) AS MONOTHERAPY FOR THE TREATMENT OF~INFECTIONS FOLLOWING HEART SURGERY (HS). s P. MUGABO, B. VANDERCAM, I. BORREMANS, M. GOENEN. Combination antibiotic therapy remains the standard for empiric management of ICU infected patients (pts). Classical combination includes a beta-lactam and an aminoglycoside. Unfortunately, nephroand ototoxicity associated with aminogly~ coside may be limiting factors in ICU pts with haemodynamic disturbances. We have conducted a prospective study to evaluate the role of IMP as monotherapy in post-cardiac surgery pts, 25 ICU pts, 24 males and 1 female, with a mean age of 58 were treated by IMP for precoce infections following HS. 21 were evaluable for the following 25 infections : pneumonia (ii), bronchitis 7, bacteremia (3), fever of unknown origin (2), mediastinitis (i and urinary tract infection (i). 72% of the infections were bacteriologically documented (24 pathogens) : P. aeruginosa (7), E. cloacae (7), Klebsiella SD (3), P. mlrabilis (2)] S ~ coccus sD (2) E. coli (I), H. influenzae (i), S, aureus ( 1 ) . IMP ~ monotheripy was effective ~-n 64% of the infections ; aminoglycoside or vancomycin was added in 20%, bacteraemic superinfection occurred in 8% and failure was noted in 8%. Three pts died from obviously not infectious causes. In terms of bacteriological efficacy, persistance of the original pathogen was observed in 7/24 (29%) organisms with 2 becoming iMP-resistant. IMP had not to be discontinued for adverse reactions. Mild modifications of the hepatic enzymes were noted in 2 pts. In conclusion, IMP as monotherapy seems a safe and effective treatment of ICU infections following heart surgery. Aminoglycoside use was needed in only 20% of the pts. Emergence of resistance, especially for P. aeruginosa, must be carefully monitored. Departments of Intensive Care and Internal Medicine ; Saint~Luc University Hospital ; 1200 Brussels, Belgium. profylachia~llytreatedbycephalosporius for at least 48hours

A 85

OP 27.05 IMMUNOCHEMOTHERAPY

OP 27.07 IN

EXPERIMENTAL

VISCERAL

LEISHMANIASIS : USE OF TREHALOSE DIMYCOLATE (TDM) WITH P E N T A V A L E N T ANTIMONY. H, Kumar, S . A h m a d and H . M . K h a n . Visceral leishmaniasis is a severe and often fatal infection in h u m a n s . T h e etiologic agent,Leshmania donovani, parasitizes tissue macrophages from within as an. obligate intraeellular parasite. Pentavalent antimonials (Sodium stibogluconate) are the drug of choice for treatment of leishmaniasis. The limitation of this treatment include potentially toxic adverse drug reactions,frequent & prolonged requirment for high doses,and relapse of infection despite apparent cure.ln our study a regimen of combined immunostimulation & chemotherapy for the elimination of L. donovani amstigotes has been evaluated.An in vivo experimental model was e m p l o y e d to study the synergistic effect of antimon,y therapy and T D M immunomodulation. Golden hamsters w h e n treated with T D M alone generated a certain degree of i m m u n e response against leishmaniasis showing a protection index, of P < 0.05, Animals treated with sodium stibogluconate alone also s h o w e d a steady decline in the parasite burden of liver & spleen. But the combined use of sodium stibogluconate & adjuvant T D M was found highly effective with significant reduction of parasites both in the liver and spleen (P~[0.01).Theimmunostimulation provided by T D M considerably helped in reducing antimonial doses normally required to reduce amastigote burden in the liver & spleen. An approximately 50% less antimenia] was needed with T D M . T h e s e observations appear quite encouraging for exploring newer approaches for the treatment of visceral ]eishmaniasia,as also for evaluating the synergistic effect of combined i m m u n o e h e m o t h e r a p y with this and possibly other immunomodifiers.

Parasitic Im munology Medical College, A M U ,

Laboratory, Jawaharlal Aligarh - 202 002. India.

Nehru

BENEFICIAL EFFECT OF RECOMBINANT GAMMA INTERFERON IN SYSTEMIC SCLEROSIS. A. Kahan, B. Amor, C.J. Menk@s, G. Strauch. Recombinant gamma interferon is a potent and selective inhibitor of collagen production by dermal fibroblasts in vitro and has numerous immunoregulatory activities. We assessed the effects of recombinant gamma interferon (Bioferon, FRG) in the treatment of systemic sclerosis which is characterized by excessive fibroblastic activity and a wide range of immunological abnormalities. Ten patients entered the study and 9 completed the 6 months period. Recombinant gamma

i n t e r f e r o n was a d m i n i s t e r e d once d a i l y by intramuscular i n j e c t i o n s : 10 ~g/d f o r 10 days, 25 ~g/d f o r 10 days, 50 ~g/d f o r 10 days, and 100~g/d f o r the f o l l o w i n g 5 months. After the 6 months treatment period, a significant improvement, as compared with baseline values, was observed in mean (+ SEM) functional index (9.7 + 1.8 vs. 4.9 § 1.1, p ~ 0.05), grip strength (right-- (mmHg) : 147 T 29 vs. 202 ~ 34, p < 0.05 ; left : 136 + 27 vs.--188 ~ 30, p < 0.05), total skin score (39 +-5 vs. 29 + 3, p < 0.01), maximal flexion of the wrists (right Wangles in degrees) : 51 + 7 vs. 62 + 7, p < 0.05 ; left : 54 + 6 vs. 62 + 7, p ~ 0.01), maximal extension of the wrists (right : 49 + 3 vs. 57 + 3, p < 0.01 ; left : 50 + 5 vs. 58 + 4, p <-0.01), dysphagia score (1.7 + 0.2 Vs. 0.7 + 0.2, p < 0.05), and creatinine clearance (1.18 + 0.11 vs. 1.52 + 0.19 ml/sec, p < 0.05). No serious-- side-effects wer~ observed ; however, a significant decrease in white blood cell counts (7.6 + 0.8 x I0s vs. 6.0 + 0.9 x 103 cells/mm s , p < 0.05) and in peripheral blood lymphocytes (2.5 + 0.3 x 10 ~ vs. 1.9 + 0.2 x 10 ~ cells/mm 3, p < 0.01) was noted. These resuTts suggest that recombinant gamma interferon may be beneficial in the treatment of patients with systemic sclerosis. Dept. Rheumatol. and IRT-ECLIMED, H6pital Cochin, 27 rue Fg St Jacques, 75014, Paris, France.

OP 27.06

OP 27.08

CORTICOSTEROID TREATMENTAND IMMUNOREGULATORYCELLS UNDER ACOUSTIC STRESS IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS (SLE), SARCOIDOSIS AND IN HEALTHY SUBJECTS H. Hinrichsen, J. Barth, R. F e r s t l , W. Kirch Changes of lymphocytes and t h e i r subpopulations a f t e r b i cycle ergometry have been described in normal subjects and patients with SLE or sarcoidosis (1,2), the immune response being less pronounced in both groups of p a t i e n t s . In the f o l l o w i n g study these a l t e r e d immune response was t r i e d to be evoked by an acoustic stress t e s t (A.W.v.Eiff, University Medical School, Bonn, FRG). The advantage of t h i s t e s t was i t s independence of the physical capacity of the pat i e n t s . Furthermore we were i n t e r e s t e d to see i f there was a dependence between the immune response and a c o r t i c o s t e r o i d therapy. 14 female patients with SLE (age 47 ~ 5 y r s . ; ~ • SEM; 9 patients with prednisone therapy), 12 patients with sarcoidosis (age 35 ~ 2 y r s . ; 7 male and 5 female; 4 patients receiving prednisone) and two age and sex matched groups of healthy controls (without medication) were included in the study. A f t e r the ten minutes l a s t i n g acoustic stress t e s t healthy %ubjects and patients with sarcoidosis showed a s i g n i f i c a n t increase in the lymphocyte count ( p < O . O l ) , marked r e l a t i v e elevations of B-.(Leul2) and T-suppressor c y t o t o x i c lymphecytes (Leu2a) (p
ADVANTAGES AND LIMITATIONS OF SOLID PHASE SAMPLING SYSTEMS IN A CICLOSPORIN MICRO METHOD H.HQIIer, H.G.F6rster, R.G.Alken Therapeutic drug monitoring is recommended in patients continously when being treated with ciclosporin after organ transplantation. Capillary blood samples can be taken by an out-patient himself and mailed to the central analytical institution. This will provide actual trough levels at his next visit to his local doctor and his specialized care unit. Filter paper or cotton carrier systems have been tested. The extraction ratio of ciclosporin varied between 0.6 and 0.7 depending on material, the shape of the blood dot on the carrier and the hematocrlt of the patient. Ciclosporin was measured by a micro-version of the monoclonal monospecific 3HCyA-RIA (SANDOZ) using between 25 and 50 pl blood. At optimized conditions the accuracy of the micromethod is comparable to the published macromethod in the therapeutic concentration range (e.g. variation coefficient less than 10% in the therapeutic range). However, the variation coefficient increases when samples are submitted on solid phase systems by mail up to almost 20~. On the other hand, at the moment more than 500 out-patients on ciclosporine are submitting samples by mail systems in the GDR. Although those factors affect analytical quality within a certain range, we conclude that solid phase sampling systems are essentially helpful in out-patients on maintenance therapy. Institute of Clinical Pharmacology, HumboldtUniversity, POB 140, Berlin, 1040, GDR

I. Hutt, H.J. et a l . Europ J Clin Invest 16, A193 (1986) 2. Hedfors, E. et al. Scand J Resp Dis 75, 151-59 (1976) I. Medizinische K l i n i k , C h r i s t i a n - A l b r e c h t s - U n i v e r s i t ~ t Schittenhelmstr. 12, 2300 Kiel I, FRG

A 86

OP 28.01 PHARMACOKINETICS OF MEPIRODIPINE (YM 7 3 0 ) AND ITS SUSTAINED RELEASE FORMULATION IN NORMAL SUBJECTS K, H a s h i m o t o , G. T s u ] i m o t o , S. M o t o m u r a , T. T e r a m u r a a n d T. T a k e n a k a Mepirodipine (YM 730}, (+}-(3'S, 4S}-3-(l'-benzyl-3'-pyrrodinyl) methyl 2,6-dtmethyl-4-(m-nitrophenyl}-l, 4-dihydropyridine-3, 5-dicarboxylate hydrochloride is a stereochemically pure enantiomer and was found to be an extremely potent calcium antagonist in producing vasorelaxation in vitro. Mepirodipine was administered orally as a single 5-, 10- and 20-mg dose in a sequentially ascending order. The m e a n pharmacokinetic parameters obtained in single-dose studies were: 1.0 h {5 rag}, 1.63 h (10 rag} and 1.17 h (20 mg} for Tmax, 0.64 ng/ml (5 rag}, 0,98 ng/ml (10 mg} and 4.68 ng/ml (20 rag) for Cmax, 2.13 ng.h/ml (5 rag), 4.44 ng.h/ml (I0 rag) and 13.14 ng.h/ml (20 rag) for AUC0-24h, 1.92 h (5 mg), 4.80 h (i0 rag} and 7.47 h (20 mg} for t l / 2 . Next, a 7day repeated-dose (7.5 mg, b.i.d.) study was performed. A steady state of mepirodipine appeared to be attained by about day 4 after the initiation of the repeated dosing: the mean Cmax were 0.74, 0.71 and 0.73 ng/ml, t l / 2 were 3.05, 4.69 and 4.91 h, and AUC0-24h were 1.48. 2.45 and 2.65 ng.h/ml for day 1, 4 and 7, respectively. Furthermore, a sustained-release formulation of mepirodipine was developed and the pharmacokinetic c o n s t a n t s of t hi s formulation (15 mg, q.d.} were evaluated. In a 7-day repeated-dose study, the ratio of peak-trough plasma concentration was 2.4 for this sustained-release formulation, which was approximately half of that obtained from a plain capsule of mepirodipine (7.5 mg, b.i.d.). The mean AUC0-24h were 3.37, 2.56 and 4.11 ng.h/ml for day 1, 4 and 7, respectively. The concentration-time profile of the sustained-release formulation of mepirodipine indicates that this formulation maintains a constant plasma concentration with little accumulation after multiple dosing and suggests a once-aday regimen for the treatment of hypertension is a possibility.

OP 28.03 CALCIUM ENTRY BLOCKADE AND AGONIST-MEDIATED VASOCONSTRICTION(VC) IN HUMANS: DIFFERENCES BETWEEN NICARDIPINE(N) AND VERAPAMIL(V). Roberto Pedrinelli, Stefano Taddei, Giovanni Panarace, Marzia Spessot, Antonio Salvetti. N is more effective than V in antagonizing either exogenous (Clin Pharmacol Ther,1988) or endogenous (JACC, 1968) ~-adrenoceptor stimulation. Whether the same holds for no]~-adrenoeeptor mediated stimuli i s unknown . We tested the r e l a t i v e e f f e c t of N and V on VC induced by Angiotensin II(A),in 6 mild uncomplicated hypertensive pts. A was infused into the brachial artery at three cumulative, systemically ineffective doses (.02, .06, .2 pg/min x 3 min each) in presence of saline (S) or either N or V at two cumulatively increasing rates (I0 & 30 ~jug/min x ]5 min each), at at l e a s t 8 hours intervals. ~orearm blood flow(FBF, venous plethysography), HR and ia MAP were recorded throughout. In spite of comparable vasodilation (N: 4.1~1.2 to 8.9• and 14.5• V: 4.• to 9.1• a n d 13.1+3.6 respectively) N(S: -25.7• -52.8• -72,1+5.1~ N I0 ~g/min: 30pg/min: -0.1i0.], 0.8• A ~ore than V(S: -22.1•

-0.3~I.6,

0.2• -3.4f8.3; N -1.411.6%) antagonized FVC to -52.2• -71.6• V 10

pg/min: -16.6• -28.9• -49.3~6.7; V 30 ~g/min: -0.4 i0.6, -9.9~]1.9, -25.?+10 7%; p<.OOi vs N). This property was not due to presynaptic f a c i l i t a t i o n of NE-release by A because localok-( phentolamine, PH, 80 pg/min x 15 min; FBF f r o m 3 . 6 ~ 1.2 to 8.2• 4.6)and~=(propranolol,100 ~g/minx 15 min)blockade did not modify the e f f e c t of A (S: -20.2• -49.1~5.9, -65.3i8.9; PH: -25.2!6.4, -49.3• -70.+8.2%; n=5 additional pts}. T h u s , when infused at equieffeetive dose, N is more effective than V in antagonizing VC, independent of receptor-type stimulation. Interference with the effect of a series of agonists may contribute to the action of N and possibly other dihydropiridines. Hypertension Unit, 56100 PISA. Italy.

l

Clinica Medica.University of Pisa.

Department of Pharmacology, Yamanashi Medical College, Tamaho, Nakakoma-gun, Yamanashi, 409-38 and Yamanouchi Pharmaceutical Co., Ltd., I-I-8, Azusawa, Itabashi-ku, Tokyo 174, $apan.

OP 28.02

OP 28.04

EFFECT OF DILTIAZEM ON SILENT ISCHEMIC EPISODES ASSESSED BY EXERCISE TESTING AND AMBULATORY HOLTER MONITORING. B.Takase, A.Kurita, A.Uehata, K.Satomura, H.Susahara, T.Nisioka, T.Maruyama, H.Hikita, K.Mizuno, H.Nakamura. Silent ischemic episodes (SIE) are associated with the prognosis of ischemic heart disease (IHD). However,SIE incidences~or:theirldunation~in?pa~lents(pts) undergoing drug therapy remain unclear. Further,the relation between Holter monitoring and exercise (EX) testing in assessment of a therapeutic drug has produced conflicting results. Thus, we performed a single blind test wherein, for the first two weeks, pts received a placebo and,for next two weeks ,90mg of diltiazem (DIL) t.i.d. Fifteen pts with chronic stable angina (CSA) with at least grade 2 angina of the Canadian Heart Association were tested. Their plasma DIL levels were measured by liquid chromatography,and the effect of DIL was evaluated by EX testing and by 48-hours Holter monitoring,both performed on the same day. SIE was defined as an episode of an asymptomatic ST segment depression (STD;~imm,~30sec), and the plasma DIL level was 50• ng/ml. DIL increased the patient's EX time, from 400 i60(• sec by 13% (p<0.01) and reduced the STD at peak EX from -1.4 • mm by 20% (p<0.01).Futher,DIL was found to reduce the episodes of angina,from 1.321.6/48hrs to 0.5 • (p<0.05). DIL,however, did not appreciably improve SIE,which went from 7.5• to 7.7• or the duration of SIE,which changed from 45259 min/48hrs to 39+66. These results suggest that the discordant effects of DIL on silent and painful ischemia may indicate that SIE,as a prognostic marker for IHD, may have a different pathogenesis.Thus,90 mg of DIL t.i.d, to control angina or to improve the pts EX endurance may be insufficient in this study,and Holter monitoring or EX testing may contribute different information. National Defense Medical College 3-2 Namiki Tokorozawa Saitama 359 JAPAN.

CALCIUM ENTRY BLOCKADE AND ALPHA-MEDIATED VASOCONSTRICTION(VC): DIFFERENTIAL INTERFERENCE BY VERAPAMIL(V) AND DILTIAZEM(D) ON ARTERIOLAR RESPONSES TO EXOGENOUS NOREPINEPHRINE(NE) IN HUMANFOREARM(F). Giovanni Panarac_~e Roherto Pedrinelli, Stefano Taddei, Antonio Salvetti. We have previously shown that a dihydropiridine calcium entry blocker(CEB)such as nicardipine blunted the VC by either exogenous or endogenous ~ -adrenoceptor stimulation.On the contrary V,an unrelated CEB,was much less effective in that regard,suggesting that differences exist among compounds belonging to t h i s pharmacological class,even as regards interference with ~-adrenoceptor mediated vascular stimuli in man.To further evaluate t h i s possibility,we studied the behaviour of another chemically unrelated CEB such as D on F VC to local i n t r a a r t e r i a l NE in n=6 hypertensive pts.The data were compared with those obtained by using V in another group of n=6 subjects.ln both groups, the brachial a r t e r y was cannnlated for drug infusion. % changes in F blood flow(FBF, ml/100 ml/min., venous plethysmography) were measured during cumulative infusion of increasing NE rates(.15, .5, 1.5 ~g/min x 3 min each)either in presence of saline(S) or a f t e r local pretreatment with D(5 & 15 ~g/min x 15 min.)or V(IO & 30 pg/min x 15 min each)administered at two cumulative rates. D and V increased FBF dose-relatedly( D: from 3.3• to 6.8• and to 9.833.9; V: from 3.4• to 7.5• and to 10.6• to a comparable extent, without changes in MAP and HR.At the l o w e r infusion r a t e , either D(S: -33.4• -57.2• -73.3• D: -48.1• -65.5• -77.7+4.8%)or V (S: -28.6• -56.9+5.3, -76.8• V: -21.1• -55.3• -76.8+7.1%) d~d not influence the vasoconstrictor effect of NE as compared with S. At the greater one, D tended,if ever,to potentiate the action of the agonist(S:-33.4~5.8, -57• -73.3+2.9%; D:-46+5.8, -63+3.6, -76• while V blunted i t to a small b u t - s i g n i f i c a n t extent(S:-28.6• -56.9• -76.8!2.6%; V12.5• -26.9~8.7, -47.3• p<.O5 vs S). Thus,in spite of the common property of blocking e x t r a c e l l u l a r calcium fluxes,chemically unrelated CEBs show a different i a t e d spectrum of e f f e c t s on vascular ~ - a d r e n o c e p t o r mediated stimuli in F a r t e r i o l e s . Hypertension Unit, I Clinica Mediea, University of Pisa. 56100 Pisa. I t a l y .

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OP 28.05

OP 28.07

EFFECTS OF ANIPAMIL ON RENAL FUNCTION IN HYPERTENSIVES. W. Kirch, A. Nokhodian, A. Schacht, A. Halabi

FELODIPINE MONOTHERAPY VS PLACEBO: A DOSE-RESPONSE STUDY IN HYPERTENSION H.Ch. Hart for the Binational MC study group in the UK and the Nethedands. A new extended release formulation (ER)of felodipine (Astra) maintains an antihypertensive effect over the 24-hour dosage interval. This study assessed the efficacy and tolerability of 3 doses of felodiplne ER compared to placebo. Methods: A total of 183 patients (mean age 52.9 years, range 28-65 years) with mild or moderate hypertension entered a 4-week placebo run-in period. If, at the end of the run-in period, supine diastolic blood pressure (BP) was >95 and <120 mm Hg, patients were randomly allocated to 4 weeks' treatment with felodlpine ER 5 mg, 10 mg or 20 mg, or placebo. At 2-weekly intervals, supine and standing BP, heart rate and body weight were mesasured 24 hours after drug intake. Adverse events (AEs) were assessed by direct questioning and spontaneous reports. Safety laboratory investigations were performed during the placebo run-in period and at the end of the study. Results: Over the 4-week treatment period, supine BP fell by 7/6 mm Hg, 9/8 mm Hg, 12/10 mm Hg and 14/11 mm Hg in the placebo group and felodipine ER 5 rag, 10 mg and 20 mg groups respectively. The BP reduction was significantly greater in the felodipine ER 10 mg and 20 mg groups compared to the placebo group. Standing diastolic BP reduction was significantly greater in all three dose groups compared with placebo. Heart rate and body weight remained unaffected by treatment. No clinically significant changes in any of the laboratory variablas were noted. A dose related effect was observed in the increased proportion of patients repQrting AEs during the active treatment pedod compared to the placebo run-in period. In the felodipine ER 5 rog, 10 mg and 29 mg groups, 4, 3 and 8 patients respectively withdrew due to AEs. The most commonly reported symptoms were headache, peripheral oedema, flushing/feeling of warmth and dizziness. Conclusion: Felodipine ER was successful in achieving satisfactory 24 hour blood pressure control. Although generally well tolerated, there was a dose-related effect on tolerability. The treatment should be initiated with 5 mg dally. Zlekenhuis "De Lichtenberg", Utrechtseweg 160, 3818 ES Amersfoort, the Netherlands

Anipamil i s a new calcium a n t a g o n i s t with s t r u c t u r a l s i m i l a r i t y to verapamil. The drug i s mainly b i o t r a n s formed by the l i v e r , only about 4 % o f i t are e l i m i n a t e d unchanged by the kidneys. In animal experiments f o l l o w i n g b i l a t e r a l renal ischemia a p r o t e c t i v e . e f f e c t o f anipamil was seen, Therefore aim of the present study was to i n v e s t i g a t e d the e f f e c t s o f anipamil on renal plasma f l o w (RPF) and glomerular f i l t r a t i o n r a t e (GFR) of hypertensives with d i f f e r e n t degrees o f renal f u n c t i o n , In a p l a cebo c o n t r o l l e d study I0 h y p e r t e n s i v e p a t i e n t s with normal renal f u n c t i o n (mean age 60 t 1.4 y r s . ; body weight 68 ~ 3.2 kg, GFR 100.9 ~ 2.2 ml/m; ~ SEM) and lO hypert e n s i v e s with chronic renal i n s u f f i c i e n c y (age 63 • l.O y r s . ; body weight 65 ~ 2.7 kg; GFR 43,6 s 5.0 ml/min) were t r e a t e d o r a l l y f o r one week with 80 mg anipamil once d a i l y . GFR was estimated t h r e e hours a f t e r a d m i n i s t r a t i o n of placebo (14 days) and anipamil by i n u l i n clearance, RPF by PAH clearance. Compared with the placebo values anipamil led to an increase in GFR from 100.9 ~ 2.2 ml/ min to 102.4 t 3.4 ml/min ( p > 0 . 0 5 ) and a decrease in RPF from 581.8 s 14,6 ml/min to 577.3 ~ 22.5 m l / m i n (p~ 0.05) in the p a t i e n t s with normal renal f u n c t i o n . In p a t i e n t s with chronic renal f a i l u r e GFR was s l i g h t l y elevated from 43.6 t 5.0 to 46.4 ~ 4.5 ml/min ( p > 0 . 0 5 ) , whereas RPF f e l l from 270.2 • 21.8 ml/min to 263.6 t 20.2 ml/min. Thus anipamil did not cause any r e l e v a n t changes in renal haemodynamics in hypertensives with normal and impaired kidney f u n c t i o n .

I. Medizinische K l i n i k , K i e l , FRG

Christian-Albrechts-Universit~t

OP 28.06

OP 28.08

EFFECT OF A NOVEL CALCIUM ANTAGONIST, MPC-1304 ON P E R I P H E R A L BLOOD FLOW-COMPARISON WITH PEAZOSIN. Y, Kuma~ai, T. Kotegawa, A, Fujimura, H. Nakashima, H. Ohira, T. Shiga and A. E b i h a r a Effect of MPC-1304(MPC) and an al receptor antagonist, prazosin(PRZ) on total finger blood flow(TFBF) as well as finger skin blood flow(FSBF) were evaluated in six healthy young volunteers. MFC(5mg), PBZ(img) or placebo was given orally at more than 4 weeks intervals. TFBF was measured by a venous oceulusion plethysmography (SP2 ~ Medimatics). FSBF of right third finger was measured by a laser Doppler perfusion meter (LASEBFLO BPM403 | TSI) before (basal) and during left hand was cooled in iced water for 30 seconds. These parameters were obtained for 6 hours after MPC and for 4 hours after PRZ. TFBF increased singnificantly after MPC and FEZ. Basal value or cooling-induced reduction of FSBF was not influenced by MPC treatment. In contrast, basal FSBF was elevated and cooling induced-reducti0n of FSBF was attenuated by PHZ t h e r a p y .

IN VIT~D hEGATIVE INOIROPIC AND VT~IIATING EFFECTS OF CAICIUM ANTf~30NISTS IN THE HI]MAN AND GUIhF-A PIG R.F.W. Ma~lds, V. Iwanov and N.F. S t r a ~ r e ~he clinical use of the different calcit~ antagonist drugs is largely determined by their relative JJZqibitory effects on cardiac m~d vascular contractility. In order to characterize their separate negative- inotropic and vasodilator actions, and also to assess the usefulness of the guinea pig as a model for the htm~n, we have studied the effects of three- different calcit~n antagonists on guinea pig papillary muscle and aortic ring preparations, and also on hi,an papillary muscle (obtained at rnitral valve resection) and digital artery rings (autopsy s p e c ~ ) . Xhe force of contraction of the cardiac raJscle to electrical stimulation at iHz was measured in the. presence of increasing concentrations of each of the drugs. Vascular effects were deters/ned by reeasuring the change in contraction induced by noradrenaline, using an area-t~ider-curve (AUC) analysis of the concentration-effect plot. Percentage of Control Contraction (mean ~ s.e.m. ) Cardiac Vascular G.P. Htm~n G.P. Htm~n Verapamll O. luM iO~+_5 76+_10 luM 80~4 56+10 92+3 47+4 l[bM 58+8 34+11 93+5 24+3 Nifedlpine O. luM 58_+6 56+7 luM 29+5 24+3 110+6 53+3 lOaM 11_+3 10+3 99~5 47+3 Diltiazem 0. luM 90_+8 69~_5 luM 77+7 45+5 108+2 73+7 10uM 57+8 28+5 124_+9 49+_4 In all cases N >~ 3 ~he ratio of concentrations producing 50% inhibition on cardiac vs vascular tissues in the htm~in was 1.5, 0.05, and 0.7 for verapamJl, nifedipine and diltiazem respectively. Xhese ratios could not be calculated for the guinea pig as there was no inhibitory effect on the aorta. We- conclude firstly that, in the htm~an, nifedipine has a greater negative inotropic effect c c ~ e d to vascu/ar effect than doe.s verapan/l or diltia~o/n, and secc~dly that the guinea pig aorta is not a good model on ~b/ch to study the vascular effects of the calcit~n antagonists. Department of M~lic/_ne, q~ze University of ~lhotti%e, Parkville, 3052, Australia.

These r e s u l t s s u g g e s t t h a t s k i n b l o o d f l o w i s n o t i n f l u e n c e d by MPC in s p i t e o f i n c r e a s e in p e r i p h e r a l b l o o d f l o w as a ' w h o l e . The p r e s e n t s t u d y a l s o s u g g e s t s t h a t s k i n b l o o d f l o w i s increased by PRZ a t b a s a l as w e l l as a t elevated adrenergic activity. D e p a r t m e n t of C l i n i c a l P h a r m a c o l o g y , Medical C o l l e g e of O i t a , 1-1506 I d a i g a o k a , Hazama, O i t a - g u n , O i t a 870, J a p a n

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OP 29.01

OP 29.03

SIMULTANEOUS PHARMACOKINETIC PHARMACODYNAMIC MODELING OF VECTOCARDIOGRAM : A ~fPICAL MULTIVARIATE SITUATION. P. GIRARD, V. LAFFONT, P. ARNAUD*, J. FAYN*, P. RUBEL*, 3.P. BOISSEL * INSERM UI21, Hop Neuro-Cardio LYON, FRANCE. Simultaneous pharmacokinetic-dynamic modeling (PK-PD) generally involved very few effect measures. On the opposite, vectocardiogram (VCO), the 3 dimensional spatial ECG, produces about 200 parameters which are amplitudes, durations, angles, rates.., computed electronically for each Of the P, QRS and T waves of heart depolarization. The following strategy was applied to isolate independent VCG parameters (PVCG), correlated with quinidine blood concentrations (C) from 8 healthy volunteers, receiving orally 350mg quinidine. Firstly PVCG were simply discarded when their AUC didn't exhibit any variation when compared to placebo. Secondly Z~PVCG, computed as the difference between drug and placebo measures,were analysed by a multivariate linear analysis of oovariance, with C as covariate. The correlations among Z~PVCG were assessed by a factorial analysis. Thirdly a classical PK-PD modelling was applied to remaining parameters. Successively, 40, 15 and finally i0 parameters were retained, concerning exclusively T wave plus the QTe parameter. The best univariate PK-PD modelling was the direct" linear link between estimated C in central compartment and the~PVCO. When normalizing each ~IPVCG with its individual maximum, no significant differences appeared between the PD parameters of the I0 models. In conclusion, the VCG confirmed that only T wave was modified by quinidine C with a unique PK-PD model for various PVCG, suggesting only one mechanism of action. More generally, the presented strategy can be useful in ether multivariate PK-PD situations showing little hysteresis. Unit@ de Pharmacologie Clinique, HOp. Neuro Cardielogique, 162 av. Laoassagne 69424 LYON CEDEX 03, FRANCE

EXPLORATORY D A T A A/qALYSIS OF PHARMACOKINETIC--DYNAMIC PARAMETERS USING INTERACTIVE 3--DIMENSIONAL GRAPHICS P. T. Pollak and J. r Q@Nsen Exploratory analysis of kinetic-dynamic data may now be done on a desktop computer using interactive 3-D graphics formerly available only on mainframes. Data from an 18-subject, 3-administration, intra- and int e r s u b j e c t v a r i a b i l i t y study of the Sandoz c o m p o u n d CBM 3 6 - 7 3 3 m a y be u s e d as an example. This serot o n i n / d o p a m i n e agonist has a p r o l a c t i n s u p p r e s s i n g effect similar to that of Parlodel| Kinetic-dynamic data were e x a m i n e d u s i n g a M a c i n t o s h T M c o m p u t e r and MacSpin T M software to produce rotatable 3~D graphs of the parameters. Rapid evaluation of the inter subject v a r i a b i l i t y w i t h i n e a c h a d m i n i s t r a t i o n p e r i o d was p r o v i d e d by simultaneous rotation of the period's 18 concentration-time (CT) curves. P r o j e c t i o n s a l o n g the time and concentration axes furnished an irmnediate i m p r e s s i o n of the v a r i a t i o n in C m a x a n d tmax. Intrasubject variability was assessed by viewing one s u b j e c t ' s 3 CT curves at once. Subject n u m b e r was u s e d as a f o u r t h d i m e n s i o n a l p a r a m e t e r to p r o v i d e views of each s u b j e c t ' s curve set in succession. Simultaneous views of the CT curves and their associated dynamic parameters (e.g. p r o l a c t i n concentration) w e r e d i s p l a y e d in the same p r o j e c t i o n to assess k i n e t i c - d y n a m i c r e l a t i o n s h i p s . The v a r i a b l e assigned to each axis can be rapidly redesignated to explore possible relationships between various parameters. Data exploration is also a s s i s t e d b y s e l e c t i o n of subsets o n s c r e e n a n d by u s i n g p o p - u p information windows to identify outliers. Conclusion: E x p l o r a t o r y 3-D graphical data~ analysis p r o v i d e s a v a l u a b l e tool for a s s e s s i n g kinetic and d y n a m i c data p r i o r to the a p p l i c a t i o n of s t a n d a r d statistical r o u t i n e s . A rapid, v i s u a l l y c o n c r e t e i m p r e s s i o n of the d a t a is e s p e c i a l l y u s e f u l w h e n s e a r c h i n g for correlations amongst kinetic data and dynamic parameters. H u m a n P h a r m a c o l o g y Dept., D r u g S a f e t y Assessment, Sandoz Ltd., CH-4002, Basel, Switzerland.

OP 29.02

OP 29.04

NONCOMPARTMENTAL STOCHASTIC APPROACH IN SIMULTANEOUS PHARMACOKINETIC-PHARMACODYNAMIC MODELING V.K.Piotrovskii, Moscow, USSR In many cases the direct relationship between therapeutic effects of a drug and its blood levels fails and one of possible reasons for this may be the peripheral (i.e. not in well-perfused tissues) location of sites of drug action. The compartmental models have been applied to model these cases, and the active sites may be placed in one of peripheral compartments of the disposition model or into the hypothetical "effect" compartment. An alternative approach is presented based upon the noncompartmental stochastic consideration inherent to which is the concept of distribution of drug molecules residence times in the immediate environment of the active site (the biophase). This distribution is the main determinant of the drug concentration in the biophase which also depends upon the drug supply from the rest of the body. In case of linear and timeinvariant kinetics of the drug in the biophase and When the drug enters the biophase directly from the circulation the biophase concentration of the drug results from the convolution of the drug concentration-time profile in blood and the probability density function of biophase residence times. Using the convolution technique one may relate the time co~rse of pharmacological effects and the drug blood concentrations for any noncompartmental stochastic model of the drug disposition in the body (polyexponential, gamma, Weibull, etc.). Thus, the simultaneous pharmacokinetic-pharmacodynamic modeling is possible without compartmental presentation for the drug disposition. Examples of using noncompartmental approach show its great possibilities.

THEORETICAL ASPECTS OF THE PKARMACOKINETICS OF RACEMIC MIXTURES OF DRUGS ELIMINATED SOLELY BY A SINGLE ENZYME James R. Gillette, Lab. Chemical Pharmacology, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892 The development of analytical methods that distinguish between enant• of drugs have greatly simplified the pharmacokinetic analysis of racemic mixtures. For systems in which one compartment models are applicable, and both enantiomers are eliminated solely by a single enzyme, the following relationship should hold regardless of the maximum concentration of the drug achieved in the system Vd I Km I Vd 2 Km 2 _ _ In (Sl(O)/Sl)= _ _ in (82(o)/$2) V V max i max 2 where S 1 and S9 represent the respective enantiomers. Thus the ratlo of t~e in (S(o)/S) values will remain constant while both enantiomers are eliminated from the body. Moreover, under these conditions the follewing relationship also holds. Vd(1) Km(1) in

Sl(~

Vmax

SI

(i)

+

Sl(o)

-

Vmax i

s1

+ S2(o) Vmax

-

s2 = t

(2)

from which the individual V and K m v a l u e s for the enmax . antiomers may be calculated. Since the relationships will not be valid when either of the enantiomers are eliminated by a combination of enzymes or elimination processes, they serve to test hypotheses that the two enantiomers are eliminated solely by a single enzyme.

A 89

OP 29.05

OP 29.07

PREDICTABILITY OF. PHARMACOKINBTIC PARAMETERS OF DRUGS IN MAN P. H. Hinderlin~ Various approaches to predict quantitatively, iv pharmacokinetic parameters such as volumes of distribution, clearances, disposition half lives and mean residence times, in man, have been reported. These approaches use either "in vitro" or "in vivo" information obtained for the test drugs. The "in vitro" procedures assess first of all relative lipophilicity of the test compounds. They then predict the pharmacokinetic behavior in man using a data base which provides correlations between lipophilicity measures and kinetic parameters in man that have been established for a representative number of either structurally related or nonrelated reference compounds. The "in vivo" methods employ kinetic information obtained for the test drug, in either one or several mararoalian species. The kinetic parameters in man are then predicted by applying appropriate scaling procedures, which consider the known iaterspecies difference, either in body weight or organ mass and blood flow. Additionally, physiological models which allow calculation of intrinsic parameters may he included. The precision of these various approaches using historic data was tested. The median prediction error of the kinetic parameters estimated in man from the in vitro and in vivo methods for different groups of marketed compounds ( ~-antagonists, benzodiazepines, ~-lactam antibiotics, and structurally non-related bases and acids) ranged between 10-80%. The prediction errors were found for some of the individual drugs to be as high as 100-400%. To be of general use in designing and developing test drugs, forecasting procedures should not produce errors exceeding 30%. Department of Pharmacology, University of Basel, Klingelberqstr. 70, 4056, Basel, Switzerland

PREDICTION OF RESPONSE TO ANTIHYPERTENSIVE THERAPY WITH ENALAPRIL AND NIFEDIPINE. P,A, Meredith~ H,L, Elliott, R. Donnellv, J,L, Reid. Using integrated concentration-effect m o d e l l i n g i t is possible in individual patients to characterise the response to enalapril and nifedipine and identify close correlations for parameters derived after first dose and longterm treatment. Therefore this approach might prove useful for predicting the longterm response from the first dose response. To evaluate this a study was undertaken in two groups of essential hypertensives who received monotherapy with nifedipine 20 mg b.d. (n=14) or enalapril 20 mg o.d (n=13). The first dose responses were characterised, using the linear model for nifedipine and the Langmuir Ema x model for enalapril, and the response profile at steady state was predicted. This predicted response was then compared with the measured response after 6 weeks treatment. For both drugs the predicted responses (pre-dosing and ~ hours post-dosing) were in close agreement with the observed responses: for enalapril observed 18.9• compared with predicted 17.6+_5.8 mmHg (mean error 1.2• (predose) and observed 37.1• compared with predicted 37.4• mmHg (mean error -0.3• (4 h post-dosing). The equivalent mean prediction errors for nifedipine at trough and 4 hours after dosing at steady state were 0.4• and -0.6• mmHg. With enalapril the observed and predicted profiles over an 8-hour study period were well correlated in all subjects. In contrast, with nifedipine, although there was generally good agreement, the model over-predicted the profile of response in 2 patients and under-predicted the profile in I patient. Thus, the application of concentration-effect analysis has utility in predicting steady state antihypertensive effect from the first dose response to the drug and may be of considerable value in deriving optimum dosing" schedules. University Department of Materia Medics, Stobhill General Hospital, Glasgow G21 3UW, U.K.

OP 29.06

OP 29.08

IMPACT OF PHARMACOKINETICS, PHAEMACODYNAMICS, AND TISSUE PENETRATION ON THE DESIGN OF CIPROFLOXACIN DOSING REGIMENS 7.J. Schentag and D.E. Nix Fifty patients with gram negative nosocomial pneumonia ~ere treated with the 6-fluoroquinolone antibiotic ciprofloxacin. Average age was 70 years. The purposes of these studies were three-fold: to evaluate efficacy and safety of this new antibiotic; to assess the kinetics of the new antibiotic in relation to bacterial minimum inhibitory concentrations (MIC); and to determine the pharmacodynamic relationships between the in-vivo eradication of bacterial pathogens and the kinetics of the drug in relation to bacterial MIC. Each patient was given ciprofloxacin 300 mg IV every 12 hours. Ciprofloxacin pharmacokinetics were assessed by measurement of blood concentrations. Tissue concentrations were estimated from blood concentrations and tissue:serum ratios. Bacterial MIG was measured on the pathogen isolated pre-treatment. The day of bacterial eradication was determined by serially culturing the patients' tracheal aspirates for pathogens. Eradication of pathogens was achieved in an average of 1.6 days. However, the pharmacokinetic behavior of ciprofloxscin greatly influenced bacterial eradication, in that pathogens whose MIC was exceeded for the entire dosing interval were more often eradicated (p< 0.05), and were erad{cated more rapidly. Initial MIC less than 0.25 was also predictive of bacterial eradication. Serum concentrations predicted response better than estimated lung tissue concentrations. Ciprofloxaein pharmacokinetic parameters differed from those of normal volunteers. The 300 mg every 12 hours dosage did not exceed bacterial MIC for the entire dosing interval of all pseudomonas, and these bacteria most often failed to respond (p< 0.05). We concluded that ciprofloxacin 300 mg every 12 hours was safe and effective, but higher dosages would be needed for many pseudomonas. The major variables (kinetics, bacterial MIC) which affect response to this antibiotic varied significantly in patient populations, making quantitation of each variable a prerequisite to dose finding studies. SUNY st Buffalo, Millard Fillmore Hospital, Buffalo NY

KINETIC-DYNAMIC RELATIONSHIPS AND INDIVIDUAL RESPONSES TO ENALAPRIL IN ESSENTIAL HYPERTENSION. R . ~ H , L , Elliott, P,A, MeredSth, J,L, Reid, ACE inhibitor drugs show large inter-individual differences in their effects on blood pressure and on the renin-angiotensinsystem and so little attempt has been made to identify dose-response and concentrationeffect relationships in individual patients. This study uses integrated pharmaeokinetic-dynamic modelling to investigate the concentration-effect relationships in 13 hypertensives who received treatment with enalapril 20 mg o.d. for six weeks. Patients attended for four 8hour study days to evaluate the pharmacokinetic and dynamic profiles following placebo, first dose and one and six weeks t r e a t m e n t w i t h enalapril. Individual patient responses were charaeterised using concentration-effect analysis and in all cases the blood pressure responses following both acute and steady state treatment were most appropriately described using the Langmuir equation with parameters Em= x (maximal effect) and Ce50 (concentration of drug pr6dbcing 50% of Emax). The reductions in both systolic and diastolic b l o o d pressure, and the inhibition of plasma ACE activity, were correlated with the plasma enalaprilat levels : after the first dose, Em~ Y was -46• (systolic) and 20• mmHg (diastolic) an~-the corresponding Ca50 values were 66• and 62• ng/ml. There were signiglcant correlations between the E m _ values for first dose and after 6 weeks treatment (r~.90; p < 0.001) for both systolic and~diastolic B.P. This study demonstrates that the r e s p o n s e t o enalapril can be characterised In individual patients and that there is a close correlation between the response to the first dose and the response during longterm treatment. University Department of Materia Medics, $tobhill General Hospital, Glasgow G21 3UW, U.K.

A 90

OP 30.01 DRUG METABOLIZB4G CAPACITY OF PATENTS OF CIRRHOSIS TREATED WITH A HEPATOPROTECT1VE HERBAL PRODUCT AND STUDY OF MECHANISM OF ITS ACTION. C.K.Chauha% S.A.Namvadekar and F.R.Billimoria A herbal product (Tefroli), containing mixture o f extracts derived from Tephrosea purpura, eclipta alba, phyllanthus Niruri, Terminalia Chebula and Ocimum sanctum has been advocated as a hepatocorrective and protective agent in various liver disorders. Since hepatocellular desease is known to be associated with impaured drug metabolism and impaired activity of hepatic enzymes, present study was designed to determine ( l ) extent of restoration, i f any, in hepatic drug metabolising capacity of patients of cirrhosis, treated with Tefroli, by estimating serum antipyrine halflife, known to be an ideal index in this respect. Antipyrine halflife and biochemical liver function t e s t s - w e r e measured before and after treatment with Tefroti. (2) effect o f pretreatment with Tefroli against acute and chronic ccl# induced hepatic enzyme injury in rats. Results indicate that (1) Two weeks oral t r e a t ment with Tefroli reduced antipyrine halflife from 29.3~ 5.2 Hrs. to 17.2 +_ 0.5 Hrs in patients of cirrhosis, showing significant improvement in metabolic efficiency o~ the l i v e r . (2) Estimation of hepatic proteins, trlglycerides, succinate dehydrogenase and Hydroxyproline content showed protective effect of Tefroli against acute and chronic cclg induced liver injury in rats. Thus this herbal product appears to be corrective and protective for hepatic function. Department of Pharmacology, LTM Medical College and Hospital,Sion,Bombay ~00 022, India.

OP 30.03 EFFECT OF I%IYA SPECIES ~ PLASMODIUMB E R G ~ I BERGH~I IN MICE. S.C. Awe~ J.H. Makinde and L.A. Salako. Khaya species commonly found in West Africa suffers from people ~ e e l ~ g its stem bark claiming to use it for treating fevers. The aqueous extracts of K. sene~alensis I ~. grandifoliola and K. ivarensis were screened for autimalarial action against ~. berghei berghei in mice. Schizontocidal effect of the extracts on early infection was evaluated by administering them daily for 4days from the day of infection. On 5th day,microscopic e~amination of blood smear of the mice showed that at 5mg/kg/day dose, the extracts respectively gave 4 4 . 7 ~ 3 . 6 , 5 5 . 1 ~ 0 . 5 and 62.2 + 1-9 percentage suppression as against 93.2 + 0.2 (n = ~ ) produced by 5mg/kg/day chloroquine (standard). The prophylactic effect was assessed by administering the extracts daily for 3 days before infection, 72 hours after, the blood smear was exaninedand the extracts demonstrated a dose - dependent chemosuppressive effect. K. seEe~alenais, ~ . grandifoliola and K. i v o r e n s i s each at 50mg/hg/day dose produced 2 2 . 5 ~ O . 9 , ~ . 3 7 ~ . 6 and 58.3 + q.2 percentage suppression respectively while 1.~kg/day pyrimethamine (standard) gave 88.2 ~ 1.6 (n = 5) percentage chemosuppressien. ~ e effect of the extract on establishedinfection was assessed by infecting the mice with the parasite, 92 hours after, the mice were treated with the extracts and the parasitaemia level examined daily for five days. The extract failed to demonstrate any significant suppression on the established infection. These extracts show some schizontocidal and prophylactic effects. They worth further investigation. Drug Research ~ud Production Unit, Obafemi Awolowo University, Ile - Ife. I~IG~L&.

OP 30.02

OP 30.04

THE INHIBITORY EFFECT OF GOSSYPOL ON HUMAN SPERM MOTILITY

MEDICINAL P L ~ N ~F~EP~Ra,~ -mmOtISA REPORT OF PBOMISIN6 , PROPHYL/~TIC EFFECT ON NALA~IA. ,d, Ms,dupe Makinde! ,Lo,A~ S,ala!
C. Y. HONG

A direct detrimental effect of gossypol on the metabolism as well as the motility of sperm had been suggested as a mechanism for its use as a male contraceptive. In this study, the inhibitory effect of gossypol on human sperm motility was quantitatively evaluated with a trans-membrane migration ratio method (TMMR) which measured the percentage of sperm that moved across the 5 micron pores of a Nuclepore membrane from semen-drug mixture into phosphate buffered saline (Hong et all Br J Clin Pharmacol. 1981; 11: 385). Seven freshly collected human semen samples were divided into several 0.1 ml eliquots and then mixed with 1, 0.1 or 0.01 mM of gossypol acetic acid. These mixures were Incubated at either 25~ or 37~ in a waterbath. After being incubated for 0, 15, 30, 60 or 120 minutes, sperm motility was measured with TMMR. Concentrations of gossypol that decreased sperm motility to 50% of untreated control (EC50) were determined from dose-response curves. At 25~ gossypol did not inhibit sperm motility. At 37~ the EC50 of gossypol were 0.5, 0.15 and 0.05 mM for 30, 60 and 120 minutes Incubation respectively. No significant inhibition could be found if the incubation time was less than 15 minutes. Since most of our previously studied sperm immobilizing agents inhibited sperm motility immediately after semen had been mixed with test substances (Hong st; Lancet, 1986; 2:402), the inhibitory effect of gossypol on sperm motility is rather weak. It is unlikely that gossypol can be developed as a vaginal contraceptive based on its spermicidal activity. Institute of Clinical Medicine, National Yang-Ming Medical College & Department of Medicine, Taiwan Veterans General Hospital, Taipei, Taiwan, ROC 11217

The p r o p h y l a c t i c e f f e c t o f the aqueous e x t r a c t s o f some Plants commonly used t o t r e a t f e v e r ~n N i g e r i a was studied using the method similar to that of W. Peter [Expt, P a r e s i t o l , 17 80 - 89 1856), Male a l b i n o Swiss mice [18 - 22 g] d~tributed into groups of fives were used, The animals were treated orally for three consecUtive days w i t h the e x t r a o t / p y r i m e t h a m i n e / d i s t i l l e d water depending on the group, Varying doses o f each e x t r a c t ? were used, The animals were then i n f e c t e d w i t h I x 10 drug s e n s i t i v e ~, ber~hei be,~hei on the f o u r t h day, Three days l a t e r , t h i n blood f i l m s were made from the m i c e and the average percentekge suppression of p a r a s i taemia was assessed f o r each group, The p l a n t s studied were Morinda l u c i d am, 8olanumerianthom, A l s t o n i a boone& and K ~ ' ~ r a n d i f o l i o l a , A l l the f o u r e x t r a c t s i n d i v i d u a l l y produced a dosedependent cbemasuppreseion, A chsmosuppress~v~ effect ranging from 44.2 + 2,8 to 81,2 + I,~/0 was resorded to a dose range of 25 t~ 200 mg/k~/da~ stem bark extract of AZstqn~a boonei while 8.7 + 1,4 to 72,1 + I.~/0 was recorded to similar doses ~f its leaf e• A dose rengin~ from 10 to 800 mg/kg/day of the stem bark extract of K h a ~ grandifoliola produced a ohemosuppressive effect ran~ng f ~ " ~ , O to 57,6 + I,~/0, Varying concentrations of the extracts of Sola~um erianthom and Moriqd~ luoida produced between 28,0+ ~ , to 78~2, I~ ohemosupprasslon and 24.3 + 2~2 to 70,4 + 27~/~ respectivel~ 1.2 mg/kg/day p y r i m e t h ~ i n ~ prodoeed 88,~ + 1 . ~ ohemcsuppression, These r e s u l t s i n d i c a t e t h a t ~ l s t s n i a boorei~ Khaza s Solarium erianthum and Mordnda i u c i d a would most probably be of p r o p h y l a c t i c use i n the treatment o f m a l a r i a . Department o f Fha~naoology G Therapeutics, College o f Medicine, U n i v e r s i t y o f Ebadan~ Ibadan, N i g e r i a ,

A 91

OP 30.05

OP 31.02

CHEMICAl

HEPATIC CONJUGATION ENZYME SYSTEMS IN HEPATOSPLENICSCHISTOSOMIASIS Mohamed E1 Mouelhi a n d M o u s t a f a M a n s o u r

C O N S T I T U E N T S AND P H A R M A C O L O G Y

OF G E N T I A N A 0 L I V I E R I

T:ErsbzX.,R.SunalXX.,i.$ahinXX.,i.~al1~X., Ten c o m p o u n d s w e r e i s o l a t e d and their structures w e r e e l u c i d a t e d u s i n g a m o d i f i e d v a c u u m liquid chromatography

from G e n t i a n a

01ivieri~

(Gentianaceae). Since

the p l a n t is t r a d i t i o n a l l y u s e d as

bitter

tonic,antidiabetic

and a n t i c o n v u l s a n t

in e a s t e r n and s o u t h e a s t e r n A n a t o l i a , t h e glycemic,antidepressant activities

of the title p l a n t m e t h a n o l i c

tract and s e c o i r i d o i d

hypo-

and a n t i c o n v u l s a n t ex-

fractions were investi-

gated. Antidepressant were o b s e r v e d iridoid

and a n t i c o n v u l s a n t in m e t h a n o l

extrects

activities and seco-

fractions. The m o i e t i e s we u s e d for

s c r e e n i n g a n t i d i a b e t i c a c t i v i t y had h y p e r g l y cemic a c t i v i t y i n use. This i n d i c a t e s

contrast

to the t r a d i t i o n a l

that the h y p o g l y c e m i c

a c t i v i t y m a y be due to u r s o l i c a c i d w h i c h we did not e x t r a c t due to the p r o c e d u r e we emp-

The s t a t u s o f p h a s e II h e p a t i c d r u g m e t a b o l i z i n g s y s t e m s r e m a i n e d u n k n o w n in m a n y l i v e r d i s e a s e s . H e p a t o s p l e n i c s c h i s t o s o m i a s i s c a u s e s g r a n u l o m a f o r m a t i o n followed b y liver fibrosis. Hepatic transferases and hydrolases associated with glucuronide, sulfate and glutathione conjug a t i o n w e r e s t u d i e d in mice e x p o s e d to 100 S c h i s t o s o m a m a n s o n i c e r c a r i a e a t 10, 1 4 a n d 2O w e e k s p o s t e x p o s u r e . To f u r t h e r c h a r a c t e r i z e t h e h e p a t i c c o n j u g a t i o n s y s t e m , granulomatous and parenchymal tissues were isolated from mice l i v e r a t 14 w e e k s a n d w e r e a s s e s s e d f o r t h e d i f f e r e n t t r a n s f e r a s e a n d h y d r o l a s e a c t i v i t i e s . In t o t a l l i v e r h o m o g e n a t e s , g l u c u r o n y l t r a n s f e r a s e (GT) a n d g l u t a t h i o n e S t r a n s f e r a s e (GST) a c t i v i t i e s w e r e s i g n i f i c a n t l y r e d u c e d a t all i n f e c t i v i t y p e r i o d s . On t h e o t h e r h a n d , s u l f o t r a n s f e r a s e (ST) a c t i v i t y w a s s i g n i f i c a n t l y i n c r e a s e d d u r i n g e a r l y s t a g e of i n f e c t i o n a n d r e t u r n e d to n o r m a l a t l a t e r s t a g e s of i n f e c t i o n (14 a n d 20 w e e k s ) . The h y d r o l a s e s , B-~ g l u c u r o n i d a s e a n d s u l f a t a s e w e r e s i g n i f i c a n t l y i n d u c e d in w h o l e l i v e r h o m o g e n a t e s . The g r a n u l o m a t o u s t i s s u e c o n t a i n e d o n l y S6%, 15% a n d 9% of t h e p a r e n c h y m a l GT, ST a n d GST a c t i v i t i e s , r e s p e c t i v e l y . In c o n t r a s t , t h e h y d r o lases were equally distributed between the granulomatous a n d p a r e n c h y m a l t i s s u e s . T h u s , t h e c o n j u g a t i o n c a p a c i t y of t h e l i v e r is a l t e r e d in h e p a t o s p l e n i c s c h i s t o s o m i a s i s a n d c a r e s h o u l d be g i v e n w h e n p r e s c r i b i n g d r u g s to s c h i s t o s o m a l p a t i e n t s . T h e s e a l t e r a t i o n s m a y c o n t r i b u t e to t h e p r e d i s p o s i t i o n of h e p a t o s p l e n i c s c h i s t o s o m i a s i s c a s e s to h e p a t o c a r c i n o g e n e s i s . ( S u p p o r t e d b y NMRDC, B e t h e s d a , MD. Work Unit No. 3 M 1 6 1 ] 0 2 B S 1 0 . A K . 3 1 1 ) .

loyed. x H a c e t t e p e Univ. Fac. P h a r m a c y P h a r m a c o g n o s y Dept.Ankara-TURKEY xxHacettepe

univ. Fac.

Dept. P h a r m a c o l o g y , Fac. Med. A s s i u t U. a n d Div. B i o c h e m i s t r y , U.S. N a v a l Medical R e s e a r c h Unit No. 3, Cairo, Egypt

Pharmacy PharmacologyDep.

OP 31.01

OP 31.03

SELECTIVE D~I'~/~MINATIONOF GLYCOSYLATED HU~9~N SERUM ALBUMLN AS A PARAM~IZ~ OF MEDIUM-TERM DIABETIC CONTROL W.W~rner r S.Pfleiderer r W.Kratzer I G.Or~nek and N. Rietbrock Human serum albumin is non-enzymatically glycosylated at a rate dependent on the concentration of glucose in blood. Sera from hyperglycemic diabetic patients (type I and II) were investigated using a sensitive affinity chr<~natography method (m-aminophenylboronic acid-agarose colmnns) before, as well as two and four weeks after satisfactory stabilization with oral antidiabetic ~ i c a t i o n or insulin. In addition, the 'normal' range of glycosylated sermn albmnin (GSA) was determined from sera attained fran 18 healthy persons. At c~snencem~nt of therapy the GSA levels were 16,8 + 3,4 % of total alb~uin fraction (n = 12), 11,2 + 1,6 % (n = 12) after two weeks and 7,5 + 0,9 % (n = 8) after four weeks. The mean normal values were 9,2 + 1,7 % (n = 18). Changes in the concentrations of GSA correlated positively (p ~ 0,05) with the other ~Teasured parm~eters (GSA/fructos~ine: r = 0,620, GSA/HbAI : r = 0,568, GSA/fasting blood glucose: r = 0,658). Determination of glycosylated serum albumin has the advantage that the assay is selective for a serum component having a half live three times shorter than that of HbA I . Measurement of GSA differentiates more precisely between the stages of diabetic therapy than does the determination of HbA I and thus may be particularly useful when measurement of glycosylated hemoglobin (HbAI) is not applicable (e.g. hemolytic anemia, liver cirrhosis, renal insufficiency). Measurement of GSA after only two weeks therapy already shows a significant LmproveLnent of the metabolic state (p < 0,05). Abt. f. Klinische Pharmakologie, UniversitZtsklinikum Frankfurt, Theodor-Stern-Kai 7, 6000 Frankfurt/Main 70 F e d e r a l R e p u b l i c of G e r m a n y

I N C R E A S E D I N T R A C E L L U L A R pH A N D Na/H E X C H A N G E IN L Y M P H O C Y T E S E X P O S E D TO L I T H I U M FOR 72 H R J J e n k i n s , L L Ng, and J K A r o n s o n I n c u b a t i o n of h u m a n l y m p h o c y t e s for 72 h w i t h 8mM l i t h i u m (LiCI) i n c r e a s e s their N a / K p u m p n u m b e r s and a c t i v i t y ( J e n k i n s & A r o n s o n , Br J Clin Pharm, in press). S i n c e this e f f e c t could be d u e to i n t r a c e l l u l a r a l k a l i n i z a t i o n , we have studied the e f f e c t of l i t h i u m on i n t r a c e l l u l a r pH and the rate of N a / H e x c h a n g e in h u m a n l y m p h o c y t e s . We p r e p a r e d l y m p h o c y t e s from the v e n o u s b l o o d of h e a l t h y s u b j e c t s by d e n s i t y g r a d i e n t c e n t r i f u g a tion, w a s h e d t h e m in c u l t u r e m e d i u m (RPNI 1640), and i n c u b a t e d them for 72 h in 10% d i a l y s e d fetal calf s e r u m in RPMI w i t h o r w i t h o u t 8 m M l i t h i u m . The c e l l s w e r e w a s h e d in TC 199 m e d i u m and the f o l l o w i n g w e r e m e a s u r e d u s i n g the i n t r a c e l l u l a r dye B C E C F / A N (Ng & Dudley, C l i n Sci, in p r e s s ) : intracellular pH, the Vma x of N a / H exchange, and the b u f f e r i n g c a p a c i t y at p H 6.0 and 7.4. The m e a n (sd; n=14) r e s u l t s are s h o w n in T a b l e i, w i t h c o m p a r i s o n s b y W i l c o x o n ' s s i g n e d rank test. T a b l e i. The e f f e c t s of l i t h i u m o n h u m a n l y m p h o c y t e pH, N a / H e x c h a n g e , and b u f f e r i n g c a p a c i t y NO Li Li 8 m M P R e s t i n g pH 7.28 (0.12) 7.32 0.13) ~0.06 N a / H e x c h a n g e (Vma x) (mmol/i/min) 14.2 (5.6) 18.2 6.0) L0.01 B u f f e r i n g ~ p H 6.0 23.7 (6.6) 29.0 9.2) L0.02 c a p a c i t y ] pH 7 4 8.6 (3.1) 8.2 2.6) N.S. ( m m o l / i / p H unit) Thus, e x p o s i n g l y m p h o c y t e s to 8 m N l i t h i u m for 72 h caused an i n c r e a s e in r e s t i n g pH, the V m a x of N a / H e x c h a n g e , and the b u f f e r i n g c a p a c i t y at pH 6.0. T h e s e r e s u l t s are c o n s i s t e n t w i t h o u r h y p o t h e s i s that l i t h i u m m a y i n c r e a s e N a / K p u m p n u m b e r s by a l t e r i n g i n t r a c e l l u l a r pH. MRC U n i t and U n i v e r s i t y Dept of C l i n i c a l P h a r m a c o l o g y , R a d c l i f f e I n f i r m a r y , O x f o r d OX2 6 H E , UK

A 92

OP 32.02

OP 31.04 T~fPORAL CRARGES IN ~ 0 M E ~ T I N G AGERTS.

P-450 M(~IOOXYGENASE S Y ~

BY

LACK OF AN EFFECT OF FOOD ON LDL-C RESPONSE TO PRAVASTATIN DESPITE A DECREASE IN BIOAVAILABILITY. H. P a n , A. D e V a u l t , B. S w i t e s , A. M i n q o , D. W a n g I v e r s o n , a n d D. W i l l a r d Pravastatin is e f f e c t i v e in d e c r e a s i n g LDL-C by 3 0 - 3 5 % a t 40 m g / d a y . Earlier studies showed a 3 0 - 3 5 % d e c r e a s e in A U C w h e n p r a v a s t a t i n w a s t a k e n with food. This present study examined the e f f e c t s of f o o d o n p h a r m a c o k i n e t i c s and pharmacod y n a m i c s in 24 h y p e r c h o l e s t e r o l e m i c patients; each received pravastatin 20mg bid with or 1 hr before meals for two 4-week periods. Lipids and serial drug levels were measured at Week 4 of each period. M e a n A U C (12 h r , n g . h r / m L ) , Cmax (ng/mL), Tmax (hr), and percent change in L D L - C from baseline ( m e a n = 222 m q / d L ) a t W e e k 4 w e r e : TREATMENT N AUC Cmax Tmax LDL-C With Meal 24 42.1, 14.3" 1.8" -36.6% Before meal 24 61.4 28.0 1.2 -36.3% *p<0.05 vs before meal Pravastatin is h e a v i l y extracted by the liver (66%). It is p o s s i b l e t h a t g r e a t e r e x t r a c t i o n m a y occur with food intake. Thus, despite moderate decreases in serum drug levels, no compromise in L D L - C r e s p o n s e w a s o b s e r v e d s i n c e t h e l i v e r is t h e primary site of cholesterol synthesis and LDL clearance. These results indicate that pravastatin can be taken without regard to meals. T h e S q u i b b I n s t i t u t e o f M e d i c a l R e s e a r c h , P.O. B o x 4000, Princeton, New Jersey 08543-4000, U.S.A.

S.M. MOOCRHAIA and E.J.D. I ~ Previous studieshave dem0nstratedthat the liver loses its capacityto metabolize and eliminate drugs during infections or during the operation of host defense mechanisms. This loss in drug metabolic capacity has been ~ttrlbuted to the selectiveloss of cytoc/aromeP-450 (C-P450) isozymes. In this stody, we investiQatedthe effects of poly rI.rCo (inducer of interfexon u and 8 ), endotoxin (lipapolysaccharide, LPS, inducer of interferon Y and t~nor necrosis factor) and latexbeads (LB, stimulantof recticuloendothelidalsystem) on the isozymes of C-P450 using some homologous ~henoxazone ethers (et/aoxy-, pento~ry-and benzyloxy-resorufin) as probe substrates for different C-P450 isozymes. Poly rI.rC, caused an initial increase in ~OD, PROD add BROD activities (apgrox. 126% of control) after 3 hrs treatment followed by a significant but differential depression of ~OD, PROD and BROD activities (51%, 81% and 86% of control respectively) 24 hrs later. LPS, on the other hand, differentially increased ~OD, pROD and BROD activities (115%, 140% and 139% of control respectively) after 6 hrs treatmentfollowedby significantbut general depression in ~OD, PROD and BROD activities (41%, 39% and 54% of control respectively), 24 hrs later. In comparision, LB caused a significantbut differentialincrease in PROD, PROD and BROD activities (128%, 162% and 139% of control respectively) following6 hrs treatment followed by a significant but differenti~i effect on EROD, PROD and ~ROD activities 24 hrs later. EROD activity was increased by 24% whereas PROD and BROD activities were depressed by 46% end 15% respectively. Except for poly IC, ~OD, PROD end BROD activities remained depressed after treatment with LPS and LB. This study shows that (a) the effects that i~sr~ec~Dd~lati~g agents have on C-~450 activitydepends on the agent used, (b) some agents can cause an initial increase in speciflc C-P450 isozyme activity and (c) the depression of cyt P450 by these agents are also isozyme specific. The mechanism(s) by which these agents modulate the various cytochrome P450 isozyme activities is still uncertain. Department of Pharmacology,Facultyof Medicine, NationalUniversityof Singapore, I0 Kent Ridge Crescent, Singapore 0511. Supported by National UniversityGrant No. RP 870372.

OP 32.01

OP 32.03

P H A R M A C O K I N E T I C S A N D T H E R A P Y O F A NEW F I B R I C A C I D D E R I V A T I V E ( B E C L O B R A T E ) IN P A T I E N T S W I T H R E N A L I N SUFFICIENCY. C. Wanner, H. Wieland, P. Flb~el, P. Schollmever and W.H. Hdrl It has been shown that clofibrate or its derivatives accumulate in c h r o nic renal faiIure ( C R F ) and dcsis a d j u s t m e n t is strongly r e c o m m e n d e d when treatment of hyperlipidemia is considered in those patients. T h e r e f o r e we investigated the e f f e c t of a single dose of beclobrate (B: 100 m g ) on plasma levels of beclobric acid in patients with d i f f e r e n t degree o f renal insufficiency. G r o u p I (CRF) consisted of 12 patients with m e a n s e r u m ereatinine of 3.9 + 0.5 m g / d h G r o u p II (TP) consisted of 11 patients after kidney transplantation (mean s e r u m creatinine 2.8 + 0.4 m g / d l ) . G r o u p III consisted o f 11 patients undergoing regular h e modialysis t r e a t m e n t (RDT). Eteven healthy subjects (CO) acted as controls. T w e l f e patients o f group II and group III s u f f e r i n g f r o m h y perlipidemia were treated three months with B (100 rag/day). Plasma levels of beclobric acid were d e t e r m i n e d by HPLC. Maximal concentration (C ) time o f m a x i m a l concentration (t ) m e a n elimination half h v e ~rFo.sel ) and m e a n trans,ent time ( M T ~ is g i v e n in m e a n values + SEM:,, CO TP CRF RDT Cmax (rag/l) 2.33 + 0.53 1.66 _+ 0.29 1.90 + 0.33 1.42 + 0,23 t as x (hours) 3,70 + 0.80 4.10 _+ 0.77 4.15 _+ 0.60 3.63 _+ 09 To. s (hours) 15.4 + 2.77 9.24 + 1.75 18.2 + 7.90 7,85 + 1.60 M T T (hours) 17.1 + 2.76 14.2 + 2.90 27.8 + 11.5 10.4 + 1.20 B decreased cholesterol (CH: 283.0 + 13.8 vs 240.7 + 10.4), L D L - C H (182.1 + 11.6 vs 154.8 + 9.11) and triglycerides (259.8 + 45.7 vs 166.5 + 22.2 m g / d l ) in group II. In group III C H decreased f r o m 254.5 _+ 18.2 to 202.7 _+ 16.0, L D L - C H f r o m 127.3 + 13.7 to 110.5 + 8.8 and V L D L T G f r o m 347.9 + 69.3 to 164.6 _+ 30,1 m g / d l . In both groups H D L - C H increased. Plasma beclobric acid levels in group II and III were: 1~t month 2.35 + 0.31 and 1.92 + 0,3; 2 na m o n t h 1.95 _+ 0.18 and 1,99 + 0.57; 3 ra m o n t h 1.68 + 0.28 and 2.11 _+ 0.52 mg/1 respectively. No s i g n i f i c a n t d i f f e r e n c e s in kinetic parameters and no correlation betw e e n elimination half live and craatinine clearance could be detected after single dose of B. Our results document both an e f f i c e n t and save e f f e c t o f B on deranged lipid metabolism and no evidence o f c u m u l a tion in patients with moderate i m p a i r m e n t of renal function before and after k i d n e y transplantation as well as patients on R D T . Med. Universit,~itsklinik, Abteilung IV, Hugstetterstr. 55, 7800 F r e i b u r g

VASCULAR REACTIVITY CHANGES IN HYPERCHOLESTROLEMIC RABBITS AS INFLUENCED BY MAGNESIUM PYRIDOXAL PHOSPHATE (SEDALIPID)

9

m

~

.

.

ax

'

M.A. Khayyal, M.R. Hegazy, A. s and M.T. Khayyal*

H. Sherif

Hyparcholestrolemia i s known t o a f f e c t c e r t a i n aspects of vascular r e a c t i v i t y . Mg pyridoxalphosphate (Sedalipid, Steigarwald, FRG) was i n v e s t i g a t e d on both normal and hyperaholesterolemic New Zealand r a b b i t s (fed on a d i e t containing 2 % c h o l e s t e r o l f o r 2 months). Sedalipid (100 mg/kg/day p.o.) was given f o r 1 month without change in feeding regimen. At the end of treatment, animals were either anaesthetized ~ith urethane and prepared for direct blood pressure measurement, or sacrificed and ring preparations prepared from their aortae and renal arteries to test their reactivity to various eqents in vitro. Blood pressure recordings revealed that high cholesterol feeding led to enhanced responsiveness to the presaor effects of norepinephrine, angiotensin II and clonidine, together with a decrease in the hypatensive affects of acetylcholine. In vitro experiments showed that arterial preparations exhibited diminished responsiveness to histamine, norepinephine, KC1 clonidine and acetylcholine, the latter two being highly affected9 All the observed changes, both in viva and in vitro were normalized to a large extent after treating the hypercholasterolemic rabbits with Sedalipid despite continued high cholesterol feeding. Depts of Pharmacology, Faculty of Medicine, Azhar University & Faculty of Pharmacy*, Cairo University, Cairo Egypt9

A 93

OP 32.04 M E D I C A T I O N C O M P L I A N C E A N D C H A N G E S IN S E R U M L I P I D S IN T H E H E L S I N K I H E A R T S T U D Y H.M~enp~, V.Manninen, O.P.Heinonen, M.H.Frick The Helsinki Heart Study was a 5-year doubleblind, randomized coronary primary prevention t r i a l a m o n g d y s l i p i d e m i c m i d d l e - a g e d men. T h e participants were randomly allocated to receive e i t h e r g e m f i b r o z i l (G) 1 2 0 0 m g / d , 2046 s u b j e c t s , or matching placebo (P), 2 0 3 5 s u b j e c t s . T h r e e d i f f e r e n t m e t h o d s w e r e u s e d for t h e e s t i m a t i o n of medication compliance. Returned capsules were counted at e v e r y follow-up visit at 3 m o n t h s ' i n t e r v a l s . U r i n e G a n a l y s e s w e r e m a d e at 6 months'intervals. A new method, the digoxin m a r k e r , w a s u s e d at t h e e n d of.the t h i r d a n d f i f t h s t u d y year. 2.2 u g of d i g o x i n w a s a d d e d t o e a c h c a p s u l e in b o t h t r e a t m e n t groups. D i g o x i n w a s measured from urinary samples by a RIA-method and the results were corrected by urinary creatinine to compensate for urine volume v a r i a t i o n s . A m o n g t h o s e w h o c o m p l e t e d t h e study, t h e r e w e r e 1 3 - 2 0 % p o o r c o m p l i e r s in t h e G and 1 2 - 1 7 % in t h e P group, m e a s u r e d w i t h t h e t h r e e m e t h o d s . T h e p e r c e n t a g e s of g o o d c o m p l i e r s w e r e 4 1 - 8 0 % in t h e G a n d 4 9 - 8 3 % in t h e P group, respectively. A distinct dose-response relationshiP was observed b e t w e e n t h e m e a n d a i l y d o s e as e s t i m a t e d b y c a p s u l e c o u n t i n g a n d m e a n l i p i d c h a n g e s of t o t a l a n d H D L - c h o l e s t e r o l a n d t r i g l y c e r i d e s in the G, b u t n o t in t h e P group. E.g. the m e a n c h a n g e s in total- and HDL-cholesterol among those who took < 5 0 % o f t h e p r e s c r i b e d G d o s e d u r i n g the ist y e a r w e r e - 1 . 1 % a n d +3.6%, w h i l e t h e c h a n g e s a m o n g those taking >75% were 10-fold and 4-fold respectively. F i r s t D e p a r t m e n t of M e d i c i n e , U n i v e r s i t y of H e l sinki, H a a r t m a n i n k a t u 4, 0 0 2 9 0 H e l s i n k i , F i n l a n d

OP 32.06 I N F L U E N C E OF A N T I E P I L E P T I C T H E R A P Y O N T O T A L A N D H I G H - D E N S I T Y L I P O P R O T E I N C H O L E S T E R O L LEVELS. E.P.Calandre, C.M.Rodriguez-Lopez, A.Blazquez. R e c e n t s t u d i e s h a v e s h o w n that p h e n y t o i n and phenobarbital increase high-density lipoprotein (HDL) c h o l e s t e r o l , a fact w h i c h has b e e n a t t r i b u t e d to the m i c r o s o m a l - i n d u c i n g p r o p e r t i e s o f these drugs. In o r d e r to i n v e s t i g a t e the e f f e c t o f s e v e r a l a n t i c o n v u l s a n t t h e r a p i e s on c h o l e s t e rol c o n c e n t r a t i o n s , we m e a s u r e d total c h o l e s t e rol and H D L - c h o l e s t e r o l s e r u m l e v e l s in 308 subjects; 233 of t h e m w e r e e p i l e p t i c p a t i e n t s c h r o n i c a l l y t r e a t e d w i t h v a l p r o i c a c i d (n=9i), e a r b a m a z e p i n e (n=36), p h e n o b a r b i t a l (n=35) or p o l l t h e r a p y (n=71); the r e m a i n i n g 75 s u b j e c t s were h e a l t h y c o n t r o l s . M e a n age v a l u e s w e r e 1 7 . 6 + 1 4 . 6 y e a r s in e p i l e p t i c p a t i e n t s and 1 5 . 5 + 1 3 . 1 y e a r s in controls; f e m a l e / m a l e r a t i o was 1 2 1 / i 1 2 and 22/23 r e s p e c t i v e l y . Total c h o l e s t e r o l was m a r k e d l y l o w e r in s u b j e c t s t r e a t e d w i t h v a l p r o i c a c i d than in c o n t r o l s (176+31 m g / d l vs 188+27 mg/dl; P < 0 . 0 5 ) . H D L - c h o l e ~ t e r o l v a l u e s weTe not i c e a b l y g r e a t e r in p a t i e n t s t r e a t e d w i t h c a r b a m a z e p i n e (66+13 mg/dl), p h e n o b a r b i t a l (63+14 mg/ dl) or p o l i t h e r a p y (6i~14 mg/dl) than in T h e c o n t r o l g r o u p (55~12 mg/dli P < O . 0 1 ) . HDL-ehol e s t e r o l / t o t a l c h o l e s t e r o l r a t i o was s i g n i f i c a n tly h i g h e r in v a l p r o i e a c i d ( 0 . 3 3 5 • and carbamazepine (0.360+0.09) treated groups than in c o n t r o l s (0.300+0.07; P < 0.01). It seems, therefore, that a n t i e o n v u l s a n t s are able to modify c h o l e s t e r o l m e t a b o l i s m at d i f f e r e n t levels, not n e c e s s a r i l y r e l a t e d to t h e i r h e p a t i c e n z y m e i n d u c i n g activity. D e p a r t a m e n t o de F a r m a c o l o g ~ a . F a c u l t a d de M e d i cine. 18012 Granada. Spain.

OP 32.05

OP 33.01

HIGH-DENSIIY LIPOPROTEIN SUBFRACIIONS, APOLIPOPROTEINS AND HEPATIC MIXED FUNCTION OXIDATION - THE EFFECTS OF PHENOBARBITAL P . V . Luoma, 3. Steng~rd, A. Rautio, J. M a r n i e m i and E.A. S o t a n i e m i A low risk of i s c h a e m i c heart d i s e a s e is typical of s u b j e c t s who have hlgh s e r u m HDL c h o l e s t e r o l , HDL 2 c h o l e s t e r o l or a p o l i p o p r o t e i n (apo) A-I level or high H D L / t o t a l c h o l e s t e r o l , H D L ~ / H D L z c h o l e s t e r o l , HDL c h o l e s t e r o l / a p o A-I or ~po A d l / A - I I ratio. P r o s p e c t i v e s t u d i e s d e m o n s t r a t e that a p h a r m a c o l o g i c e l e v a t i o n of serum HDL l e v e l may be of value in the p r e v e n tion of a t h e r o s c l e r o s i s . In this study HDL s u b f r a c t i o n s , a p o l i p o p r o t e i n s and h e p a t i c mixed f u n c t i o n o x i d a s e (MFO) a c t i v l t y as a s s e s s e d by a n t i p y r i n e k i n e t i c s were d e t e r m i n e d in 21 h e a l t h y s u b j e c t s both b e f o r e and d u r i n g i n d u c i n g t h e r a p y with p h e n o b a r b i t a l . HDL c h o l e s t e r o l , HDLe c h o l e s t e r o l and the NDL2/ HDL 3 c h o l e s t e r o l snd-HDL c h o l e s t e r o l / a p o A-I ratios were p r o p o r t i o n a l to MFO a c t i v i t y . P h e n o b a r b i t a l , 100 mg at b e d t i m e For seven days, i m d u c e d MFO and i n c r e a s e d the apo A - I / A - I T ratio. The i n c r e a s e in apo A - I / A - I T ratio can result from the i n d u e l n g effect of p h e n o b a r bital on the apo A-I mRNA s y n t h e s i s . S u b j e c t s who had high MFO a c t i v i t y zn the liver had s e r u m HDL s u b f r a c t i o n and a p o l i p o p r o t e i n p r o f i l e typical of s low risk of i s e h s e m i c heart disease. Deparfiment of Medicine, University of 0ulu SF-90220 Oulu, Finland

PLASMA HORMONE CONCENTRATIONS IN WOMEN ON THE ORAL CONTRACEPTIVE PILL G. Shenfield, J. Griffin, J. Lyons and J. Boutagy Several studies have shown wide inter-individual variations in steady state plasma concentrations of oral contraceptive steroid hormones (OCS). There is therefore no direct relationship between dose and clinical efficacy or side effects. Theoretically plasma concentrations of OCS should have a better correlation with clinical outcome. We have developed radioimmunoassays for ethinyloestradiol (EE) and Levonorgestrel (LN) and related plasma concentrations of both to clinical features in 55 women on OCS. Fur EE minimum detectable concentration was 12.Spg/ml. CV% at 40 and 300 ng/ml was 18.5% and 8.4% respectively (n=10). For LN minimum detectable concentration was 0.1ng/ml and CV% at 0.8 and 3 ng/ml was 13.6% and 10.9% respectively (n=10). Trough blood samples were taken on Day 14 of active hormone treatment. The range of results for each dosage group were wide and overlapping: Oestrogen dose(ug) 30(n=37) 35(n=9) 50(n=9) EE(pg/ml)Range 0-73.0 0-91.4 0-108.5 Mean (SD) 20.6(21.3) 55.2(31.0) 30.6(31.4) Progesterone dose(ug) 125(n=26) 150(n=14) 250(n=4) LN(ng/ml)Range 1.8-9.0 1.3-6.9 3.1-5.5 Mean (SD) 4.8(2.1) 3.4(1.6) 4.5(1.2) In all cases sex hormone binding globulin was >37.9nmoi/I. In 9 out of the ii women with breakthrough bleeding plasma EE was below 29 pg/ml, but LN ranged from 1.3 to 7.2 ng/ml. Of the 13 women with headache (2 migraine) the LN ranged from 2.0 to 7.2 ng/ml (mean 4.5 ng/ml). Other side effects did not appear to correlate with hormone concentrations or the ratio betwen EE and LN and it may be necessary to assay free hormone concentrations. Department of Clinical Pharmacology, Royal North Shore Hospital, St Leonards, NSW, 2065. Australia.

A 94

OP 33.02

OP 33.04

COMPARISON OF THE METABOLICAND HEMOSTATICEFFECTS OF TWO LOW DOSE ORAL CONTRACEPTIVESIN MIDDLE-AGED WOMEN C.R. Sirtori, G. Franeeschini, L. Calabresi, P. Bilotta. S. Winkler and A. Zamoetti The metabolic and hemostatic effects of two low dose oral contraceptives (OCs), a tri-phasic (ethinylestradiol+lnorgestrel) and a new low dose Inonophasic (ethinylestradiol+desogestrel) preparation, were compared in a cross-over trial (6-cycles for each) in 10 women over 35 y. Both combinations moderately affected plasma lipids, with 17-24% increases of total triglyceridemia. Triglycerides accumulate almost exclusively in low density lipoproteins, thus suggesting the possible formation of an atherogenic lipoprotein particle. ' Only the mono-phasic preparation increased high density lipoprotein (HDL) cholesterol levels significantly, with a rise in HDL 3 mass and associated cholesterol. Both in the HDL2 and in HDL 3 subfractions, OC treatment led to slight changes in lipoprotein structure, concomitant with a rise of the cholesteryl ester and ~riglyceride contents in HDL, indicative of a stimulated cholesterol esterification and reverse transport. The more pronounced effect of the mono-phasic vs tri-phasic preparation might be related to the androgenic profile of the latter, antagonizing the estrogen inhibition of hepatic lipase. Changes in the hemostatic indexes (fibrinogen, antithrombin III and protein C) were negligible after both OCs. The new low dose OCs, tri-phasic and mono-phasic, even when prescribed to relatively older women, affect to a relatively small extent lipidflipoprotein metabolism, with the possible exception of changes in the low density lipoprotein composition. The mono-phasic preparation is associated with an apparent improvement in the function of the high density lipoprotein system. Chair of Clinical Pharmacology, University of Milan and Ob-Gyn Division, Niguarda Hospital, Via Balzaretti 9 , 20133 Milano, Italy

IN VITRO BIOASSAY FOR CALCITONIN: PHARMACOLOGICAL AND CLINICAL APPLICATIONS A. Grauer, H. Reinel, J. Schroth, H.-G. Schneider, F. Raue, R. Ziegler Calcitonin (CT), a peptide hormone of 32 amino acids, is produced by the C-cells of the thyroid and inhibits osteoclastie bone resorption. This function has prompted its therapeutic application in Paget's disease of bone, hypercalcemia of malignancy, and osteoporosis. The usual calcitonin bioassay utilizes the hypoealcemic effect of the hormone in rats, it is time-consuming, insensitive, and expensive. We have now developed an in vitro bioassay using the human breast cancer cell line T47D, which expresses calcitonin receptors coupled to adenylate cyclase. We have determined, the biological activity of various preparations of CT of different species in this in vitro bioassay. T47D cells were plated 24h prior to the experiment (150000 cells/dish). The addition of CT for 15 rain at 37~ was followed by the removal of the medium, lysis of the ceils and determination of intracellular cyclic AMP (cAMP) generation in the lysate. The detection limit for ltqman e~lcitonin (hCT) was lower than 10-'UM (CIBACALCINtX), a linear relationship b e t w e ~ CT and chAMP could be established between 10-*VM and 10-~ hOT. Two preparations of salmon calcitonin (sCT) revealed a liq~ar relatior~hip between sCT and cAMP in the range of 10-**M to 10-'OM aCT. These results are in accordance with the relative biological activities determined in the rat hypocalcemia bioassay. We investigated the sera of 7 patients with Paget's disease of bone who developed aCT-binding antibodies after treatment with intranasal sCT. In 4 of 7 patients the posttreatment sera had a neutralizing effect on the aCT-mediated cAMP formation - this phenomenon was accompanied by the development of clinical resistance against sCT in these patients. Our data suggest that this in vitro bioassay for calcitonin is a sensitive and reliable tool to determine the biological activity of calcitonin for pharmacological purposes and to determine neutralizing antibodies against sCT after calcitonin treatment.

OP 33.03

OP 33.05

STIMULATED INSULIN PRODUCTION RATE FOLLOWING IV GLIMEPIRIDE (NeE 490) IN HEALTHY MAN. K . R a t h e i s e r , M . K o m j a t i , Adrienne Kern, H . V i e r h a p p e r , W.Waldh~usl; M.Badian,W.Malercyk.

P U L S A T i L E G O N A D O T R O P I N S R~L~ASIUNG HOP@IONS T~ATbi~kq" IN W01,1~N W I T H IN~h[PILI'Ff O F IIYP0TI~tLAidIC O R I G I N

This study e v a l u a t e s s t i m u l a t e d i n s u l i n p r o d u c t i o n r a t e ( i n c r e m e n t a l AUC x MRC of C - p e p t i d e ) and blood 91ucose (BG) response a f t e r IV a d m i n i s t r a t i o n of g l i m e p i r i d e (GLI: 0.25, 0 . 5 , 1.25, 1.5 mg) in h e a l t h y man (27+4 y r ; N=6 each). M e t a b o l i c c l e a r e n c e r a t e (MC~) of C - p e p t i d e was determined i n t r a i n d i v i d u a l l y f o l l o w i n g primed c o n t i n u o u s i n f u s i o n of b i o s y n t h e t i c human C - p e p t i d e at r a t e s of 10, 20 and 30 nmol/h. Thereby, i t was shown t h a t IV bolus a d m i n i s t r a t i o n of GLI causes a dose-dependent r i s e in i n s u l i n p r o d u c t i o n r a t e from 18+17, 25+12, 36+14 and 54+34 pmol/kg body w e i g h t ? This ~ f f e c t Was p a r a l l ~ l e d by a f a l l in BG (decremental area under the BG b a s e l i n e ) by 40~36, 69~20, 161~46, and 113+61 m m o l . m i n / l . In summary: (a) I n s u l i n r e l e a s e is i n c r e a s e d by IV GLI in a dose dependent manner, w h i l e (b) a p a r a l l e l d e c l i n e in BG was o n l y seen up to 1.25 mg GLI. The less marked f a l l a f t e r 1.5 mg IV h i n t s at p o s s i b l e glucose c o u n t e r r e g u l a t i o n . In a d d i t i o n , i t is shown t h a t i n t r a v e n o u s G L l - s t i m u l a t e d i n s u l i n r e l e a s e has not y e t p l a t e a u e d at an IV dose of 1.5 mg, though i t reduces glycemia markedly at a dose of 1.25 mg. l.Med.Univ.Klinik,

L a z a r e t t g a s s e 14, 1090 Wien

Bola/lowski M . , ~dilewicz A~ , G r a b i f m k i hi. , a n d Dept. of C l i n i c a l P h a r m a c o l o g ~ Dept. of ~ n d o e r i n o l o g y , II Dept. of O b s t e t r i c s , ~ledioal ;kcademy, Wroolaw, P o l a n d /_nfertility of h y p o t h a l a m i c o r i g i n is c a u s e d by the d e c r e a s e of e n d o g e n o u s GnRll p u l s e f r e q u e n c y axld/or a m p l i t u d e . In the t r e a t m e n t of this killd of ir~fertility, Gl%l~ is a d m i n i s t e r e d 5-11 a p u l s a t i l e m a n n e r in order to m i m i c the e n d o g e n o u s h o r m o n e r e l e a s e . T h e p u r p o s e of the s t u d y was to c o m p a r e the e f f i c a c y of t~o d i f f e r e n t s c h e d u l e s of p u l s a t i l e Gn_RH a d m i n i s t r a t i o n in women ~ i t h hypotll~lamio i n f e r t i l i t y . 9 he t r e a t m e n t was c a r r i e d out by meaxls of p e r i s t a l t i c pu/np Z y k l o m a t in 14 p a t i e n t s . T h e dose of the h o r m o n e ~as e s t a b l i s h e d a c c o r d i n g to the g r a d e of h y p o t b ~ l a m i e dysfu/uction. I n g r o u p I /7 patients/ the p u l s e f r e q u e n c y was 90 mill. i n ~ r o u p F~ / 7 other p a t i e n t s / it ~ a s i n c r e a s i n g d u r i n g the f o l l i c u l a r p h a s e f r o m e v e r y 280 to e v e r y 90 mill. fn g r o u p I ~e eonfix~med 8 o v u l a t i o n s s.ud 3 pre~ula~neies for 11 t r e a t m e n t o y o l e s ~ a n d il% g r o u p i~ - 6 o v u l a t i o n s , b u t n o p r e g n a n c y for 9 t r e a t m e n t c y c l e s . T h e p u l s e f r e q u e n c y c h a n g i n g in the e a r l y - a n d m i d f o l l i e u l a r p h a s e does n o t i m p r o v e the res u l t s of treatment il% ~ o m e n ~ i t h i n f e r t i l i t y of h y p o t h a l a m i e origin. Oepar~nlent of ~ndoeril~ology, l.iedieal ~eadenly, 5 0 - 3 6 7 W r o c i a w , ul. P a s t e u r a 4, P o l a n a

A 95

OP 33.06

OP 34.02

EVIDENCE THAT THERAPEUTIC MONITORING OF TOLBUTAMIDE CONCENTRATIONS WOULD NOT BE HELPFUL IN NON-INSULINDEPENDENT DIABETES (NIDDM)

DELIVERY OF MESALAZINE (5-AS) TO THE DISTAL ILEAL LUMEN BY AN ORAL SLOW RELEASE PREPARATION U. Klotz, P. Layer, B. Nehlsen and H. Goebell

R.E.Ferner, M.L.Antsiferov,

M.D.Rawlins.

The relationships between blood glucose, and plasma insulin and tolhutamide concentrations were studied in 20 outpatients with NIDDM, aged 63• [meanis.d.] years, body mass index (bmi) 25.7• fasting blood glucose (FBG) 8.7• mmol/L, who were treated chronically with tolbutamide, in a daily dose of 2.0 [range 0.5-3.0]g. Base line samples were taken before the patient's usual dose and breakfast, and again at 6-8 random and irregular intervals from 30-450 minutes after dosing. Stepwise multivariate regression analysis was used to study the interrelationships. Pre-dose tolbutamide concentration 19.8 [4.3-58.2] mg/l, was unrelated to dose (partial r2=0.043) or bmi (partial r2=0.075). Maximum measured tolbutamide concentration, 90.6 [39.8-155] mg/l~depended on dose (partial r==0.52, p=0.0005) and possibly on pre-dose tolbutamide concentration (partial r2=0.19, p=0~ FBG was positively related to dose (co-efficient = 1.74, partial rZ=0.296, P=0.016) and bmi (partial r 2 = 0.16, P=0.091), suggesting that patients with higher fasting glucose were given larger doses; HbAldepended on FBG (partial r2=0.641, P=0.0004), but neither FBG nor HbA 1 depended significantly on pre-dose or maximum tolbutamide concentration. Whilst tolbutamide concentration is related to dose, there is no c l e a r relationship between glucose and tolhutamide concentration and therapeutic monitoring would not be helpful. Wolfson Unit, University of Newcastle upon Tyne NEI 7RU

It is assumed that 5-aminosalicylate (5-AS) Is locally effective in the treatment of chronic Inflammatory bowel disease (IBD). Recently an oral slow release preparation (Salofalk R) has been developed to deliver 5-AS directly to the site of inflammation. To study its release pattern 8 healthy volunteers were intubated with an oroileal muitiluminal tubing system that permitted aspiration of luminal content from duodenum, mid-jejunum and distal ileum as well as perfusion with dilution markers and small intestinal manometry. Subjects swallowed 2 tablets (each containing 250 mg 5-AS) with a standard test meal (300 kcal) containing phenol red as a recovery marker. Intestinal and plasma samples were collected in 30 min intervals up to 10 h and were analyzed by HPLC for 5AS and its major acetylated metabollte (Met). Delivery patterns and luminal concentrations of both compounds were correlated at each site. Peak levels in the ileum were associated with maximal plasma concentrations. mean lag time, h ~n ax' hu - I ax' g/m

duodenum 5-AS Met 3.8 4.1 5.8 6.0 33 25

jejunum 5-AS Met 4.1 4.3 6.4 6.7 103 104

ileum 5-AS Met 4.8 4.9 7,2 7.4 290 133

plasma 5-AS Met 4.6 4.7 7.0 7.1 1.1 1.3

It can be concluded that the 5-AS tablets did not disintegrate intragastrically but dissolved gradually during interdigestive intestinal transit and targeted high 5-ASI concentrations to the distal small bowel. A substantial proportion of 5-AS seems to be aeetylated intraluminally. The data suggest that adequate amounts of 5-AS are available to be locally effective in the treatment of IBD especially Crohn's disease. Supported by the Robert Bosch Foundation, Stuttgart. Dr. Margarete Fischer-Bosch-lnstltut fQr Klinische Pharmakologie, Auerbachstr. 112, D-7000 Stuttgart 50 / FRG.

OP 34.01 AN INVESTIGATION INTO METHODSOF PREVENTION OF THEOPHYLLINE ABSORPTIONFROMACCIDENTALOR DELIBERATE OVERDOSE N.A. Minion, J.A. Henry, E. Glucksman, A.J. Miller, L.3. Rolls, K.a. Smith A single dose pharmacokinetic study was performed to evaluate three traditional methods of management of theophylline overdose. The design was a randomised four way crossover in twelve healthy fasted volunteers. Theophylline overdose was simulated by the administration of 3 x 200 mg UNIPHYLLIN Paediatric CONTINUS tablets and 16 matching placebo tablets. One hour later, volunteers received either a) an emetic 30 ml syrup of ipecacuanha, administered with 200 ml water, b) gastric lavage with a wide-bore (FG30) lavage tube, using 3L tap water in repeated 300 ml aliquots, c) ora] activated charcoal - 50 g Carbomix administered in 400 ml water, with 25 g 4h and 8h later, or d) no treatment. Blood samples, taken over 24 hours, were analysed for plasma theophylline concentrations by HPLCwith UV detection. The area under the 24 hour plasma time-concentration curve (AUC24) f o r the t h r e e a c t i v e treatments was compared to the untreated group. The mean r e l a t i v e systemic a v a i l a b i l i t i e s o f t h e o p h y l l i n e f o r the emesis, g a s t r i c lavage and a c t i v a t e d charcoal treatments were 107.14 (954 Cl 99.7-115.1%), 101.14 ( 8 i . 6 - 1 2 5 . 3 4 ) and 16.94 (12.4-23.24) r e s p e c t i v e l y . These r e s u l t s demonstrate c l e a r l y t h a t emesis and g a s t r i c lavage did not a f f e c t the absorption o f theophylline. This suggests t h a t most o f the s u s t a i n e d - r e l e a s e t h e o p h y l l i n e t a b l e t s had passed out of the stomach w i t h i n i hour, rendering them i n a c c e s s i b l e to removal by these techniques. In c o n t r a s t , the a d m i n i s t r a t i o n of a c t i v a t e d charcoal r e s u l t e d in a h i g h l y s i g n i f i c a n t reduction (p < 0.001) in the e x t e n t o f t h e o p h y l l i n e absorption. A c t i v a t e d charcoal t h e r e f o r e merits c o n s i d e r a t i o n as the the most a p p r o p r i a t e method o f treatment in t h e o p h y l l i n e overdose.

OP 34.03 A COMBINED GASTRO-INTESTINAL TRANSIT AND ABSORPTION STUDY ON FELODIPINE EXTENDED RELEASE TABLETS B~Abrahamssonl, M.Alpsten2, M Hugosson1, J.TSlli2, J. Aberg 1 An extended.release (ER) tablet has been developed for the calcium antagonist falodipine (Plendil~. The ER tablet is based on the hydrophilic matrix principle. The in vitro release rate is constant over about 10 hours which in vivo results in effective drug levels over 24 hours after dosing [Hedner T. et al, Drugs 34 (suppl 3),125,1987]. Despite the extended period of drug release, no loss in bioavailability is obtained for the ER tablet in compadson with an oral solution [Wingstrand K. et al, International Conference on Pharmaceutical sciences and Clinical Pharmacology, Jerusalem 1988, abstract p.81]. In the present study, comprising 8 healthy male subjects, the gastrointestinal (GI) transit was studied by gammascintigraphy together with plasma sampling over 24 hours. Felodipine ER tablets 10 mg were marked with coated, insoluble forms at 51Cr (3 MBq) and 59FS (0.2 MBq). The In " vitro characteristics were not different from unmarked felodipine ER tablets. The 9tablets were administered under fasting conditions and after a light breakfast (1900 kJ) at two separate occasions to each subject. The mean gastric emptying of the tablets was 0.6 h (range 0.1 - 1.1 h) and 3.2 h (r~nge 1.9 - 4.8 h) after adminislralion under fasled and non-fasted conditions, respectively. The small intestinal transit time was approximately equal for the two administrations with mean values of 4.7 h (range 3.9 - 5.9 h) and 5.1 h (range 2.2 - 7.7 h) for administration following fasting and after a meal, respectively, The faster colonic arrival obtained following fasting, 5.3 h (range 4.0 L 7.0 h), compared to the corresponding time for the administration with food, 8.3 h (range 6.0 - 11.0 h), was not accompanied by a reduced extent of absorption. The AUC was of the same magnitude, with a mean (SD) relative bioavailability (AUCf~am~d) of 0.90 (0.11). At the time of colonic ardval about 40 % (fasted) and 15 % (fed) of the dose remained to be absorbed as determined from mean in vivo dissolution-time data obtained by deoonvolution. Thus, when the drug is administered in the investigated dosage form, felodipine seems to be absorbed also in the colon. 1 AB H~ssle, S-431 83 MSlndal, Sweden 2 Radiation Physics Dept, University of GOteborgSahlgrenska Hospital, S413 45 GOteborg, Sweden

A 96

OP 34.04

OP 34.06

FOOD INCREASES NITRENDIPINE BIOAVAILABILITY. K, A. Conrad, T. C. Fagan, M. J. Mack• A. L. Mazzu, G. J. Krol apd O. E. Burkholde_r Nitrendipine (N) is a direct arterial vasodilating dihydropyridine calcium entry blocker ant• agent. Meals have been shown to affect the pharmacokinetics of many drugs, including other calcium entry blockers and other highly lipophilic agents such as propranoloL Twenty-one patients with essential hypertension, 15 male, 6 female, age 22-65, weight 160-226 pounds participated. In the fasting state, the patients received a single 20 mg dose (FD) of N and had serial blood samples drawn for N levels over a 24 hour period. At the end of treatment with N 20 mg once daily in the morning for 2 weeks, in a randomized, crossover design, on consecutive mornings the patients ate a 770 Kcal meal (40% protein, 20% carbohydrate, 40% fat) and a sham meal (looked at and smelled the meal and watched others eat). Plasma N sampling was performed for the 2 consecutive 24 hour periods. Fifteen of the patients received placebo for 2 weeks and then had repeat serial N sampling after _2additional weeks of N 20 mg once daily in the evening.

BIOAVAIhABILITY AND PHARMACOKINETICS OF TWO FORMULATIONS IN 12 VOLUNTEERS

FD AM A/~ PM PM

SHAM MEAL SHA~ MEAL

AUC ng" h r / m l 86• 82• i04• 96• 148•

Cloral Cmax L/hr/Kg ng/ml 3.7• 19• 4. 123 .O 15• 3.1• 21• 3.6• 17• 2.4_+1.8,*,23•

Tmax hr 1.8• 2. i• 2.9• 1.7+O.6 2.4_+1.2 *

Values shown are mean • SD 9, p<0.05; **, p<0.01; ***,p <0.001 compared to SHAM There was no cumulation of N during the 2 week dosing period. AUC was increased with food, and apparent oral clearance was reduced with food. Cmax was higher after the morning meal and tended to be higher after the evening meal. Tmax was longer after the evening meal and tended to be longer after the morning meal. Food slows absorption and significantly increases the bioavailability of Nitrendipine. Department of Medicine, University of Arizona College of Medicine, 1501 N. Campbell Ave. Tucson, AZ, 85724, USA.

COLCHICINE

J~.M. Scherrman~n* G.Achtert 2 , M. Rochdi I and M.O. Christen 3 Colchicine is an ant• drug obtained from COLCHICUM. The aim of this study was to evaluate the bioavailability and pharmacokinetics o f two colchicine formulations (coated tablets (A) and oral solution (B)) after single dosing of img of colchicine.The study was performed in a randomized , two-fold cross-over design (latin square) with 12 healthy male volunteers, the colchicine kinetics was determined by taking blood samples up to 72, and urine samples up to 96 hours. The quantitative determination of colchicine in serum and urine was performed by a specific radioimmunoassay. Mean peak plasma concentrations of 4.15 • 2.35 (A) and 4.88 • 3.98 (B) ng/ml were reached at 1.15 • @.38 (A) and 1.13 • @,42 (B) hours. The mean terminal half lives accounted for 9.31 • 3.98 (A) and 18.57 • 5.53 (B) hours. The mean ratios Cl/F{total clearance /absolute bioavailability) and V/F (volume of distribution /aSsolute bioavailability) were found to be 52.76 • 27.51 (A) and 46.58 • 24.65 (B) liter/h and 621.82 • 258.5@ (A) and 624.89 • 384.@9 (B) liter, respectively. The mean total amount excreted in urine (Ae) was 172.66 • 91.51 (A) and 174.85 • 63.53 (B) ~g. The statistical evaluations of the pharmacekinetics parameters showed no significant differences, neither for the extent of absorption (as indicated by AUC), nor for the rate of absorption (as indicated by Cmax and Tmax) between both preparations. i D~partement de pharmacocin~tiqne Facult~ de Pharmacie, INSERM U 26 h6pital Fernand Widal, Paris France, 2 Kali-Chemie, Hanover, R.F.A and 3 L.T.M Suresnes, Paris France.

OP 34.05

OP 35.01

COMPARATIVE PHARMACOKINETIC STUDY BETWEEN ISQPTIN 240 SR AND ISOPTIN INSTANT RELEASE. M,U.R,NAIDU~ T,RAMESH AND R.DATLA.

THE D E V E L O P M E N T OF A S U I T A B L E E X P E R I M E N T A L M O D E L FOR A S S E S S I N G THE 0 T O T O X I C I T Y OF D R U G S Z.J. Oal, X.M. Gao, Y.Y. H u a n g and Y.H. L i u The a t t e m p t of present s t u d y was to d e v e l o p a novel m e t h o d for the a s s e s s m e n t of ototoxicity of drugs, u s i n g a u d i o g e n i c s e i z u r e s (AS) in rats as an e x p e r i m e n t a l model. Rats w i t h stable A S - p o s l t i v e r e s p o n s e s were selected. There w e r e two types of seizure p a t t e r n s w h i c h were c a l l e d as r u n n i n g (R) type and conv u l s i v e (0) type, each w a s d i v i d e d into two subtypes, namely Rg, R2 and CI, C2, a c c o r d i n g to n u m b e r of times of r u n n i n g d u r i n g the seizure period. The AS i n t e n s i t y was scored as I, 2, 3 and 4 for s u b - t y p e s R1, R2, C2 and C1, respectively. The AS t e s t s w e r e done on e v e r y o t h e r day. The o t o t o x i e i t y of s e v e r a l aminoglycoside a n t i b i o t i c s , i.e., s t r e p t o m y c i n , k a n a m y c i n , amikacln, g e n t a m l c i n and n e o m y c i n was compared. The loss of A S r e s p o n s e s in three c o n s e c u t i v e tests was c o n s i d e r e d as the a p p e a r a n c e of o t o t o x i c i t y . R e s u l t s showed that the d o s a g e for i n d u c i n g 100% d i s a p p e a r a n c e of A S r e s p o n s e s was 60, 200, 200 m g / k g T d a y ip, and the n u m b e r of days (mean + SE) of d i s a p p e a r a n c e of A S r e s p o n s e s were 15.4 + 1.3 21.6 + 3.3 and 22.1 + 2.1, for neomycin, k a n a m y cin and amikacin, respectively; for s t r e p t o m y cin, the d o s a g e u p to 200 m g / k g / d a y ip c a u s e d a 20% d i s a p p e a r a n c e rate w i t h days of J8 + 3 for l o s s i n g h e a r i n g ability. A n o t h e r series of exper i m e n t s showed that g e n t a m i c i n in d o s a g e of 72 m g / k g ip once a d a y caused a 5 4 . 5 % d i s a p p e a r a n c e rate of AS r e s p o n s e s ; the same d a i l y dose of the r ~ but g i v e n in two divided doses caused a . d i s a p p e a r a n c e r a t e of AS r e s p o n s e s only. Institute of C l i n i c a l P h a r m a c o l o g y , B e i j i n g Medical University, 8 X• Shl Ku Street, Beljing 100034, P e o p l e ' s R e p u b l i c of ghlna.

In order to reduce the required number of daily doses of verapamil, a slow release (SR) tablet was developed, We have compared its kinetics with an instant release (IR) tablet. A crossover study with two formulations was carried out in ten healthy male volunteers after multiple oral dosing. On the fifth day of repeated admiistration, peak veramapil concentration 328.8-+ 191.57 ng/ml was reached early at 1.45 -+ 0.36 hour, with IR. Lower and delayed peak 134.20-+ 71.63 ng/ml at 4.7-+ 1,34 hour was noticed with SR. Comparatively longer half life 12.60-+ 5.62 hour was observed with SR, while it was 3.90 -+ 0.98 hour with IR, There was no significant difference in area under the curve (AUC) among these two preparations. 1379.93-+ 582.05 ng/ml/hr and 1731,95 + 453.10 ng/ml/hr, AUC were obtained with IR and SR Isoptin respectively. Quick rise and higher peak verapamil concentration was noticed with IR. While SR showed slow rise and gradual lowering nf concentrations~ Isoptin SR produced less peak to trough fluctuation. Both the preparations ahoy ~d similar bin-availability.

Department of Clinical Pharmacology, The Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad 500 482 (A.P), INDIA.

A 97

OP 35.02

OP 35.04

PARAFFIN AND TRADITIONAL MEDICINES AS THE MAJOR AETIOLOGICAL AGENTS CAUSING ACUTE POISONING IN A DEVELOPING A F R I C A N C O M M U N I T Y P.H. Joubert and K.L. Mathibe During the 8-year period (1981 - 1988), 3095 patients with acute poisoning were admitted to Ga-Rankuwa hospital which is situated between one of the industrial areas of Pretoria and the town of Ga-Rankuwa. Almost 80~ of these patients were children under the age of 10 years, In contrast to the situation in developed countries, drugs are r e l a t i v e l y unimportant as a cause of acute poisoning, accounting for less than 10% of cases. The major aetiological agents are p a r a f f i n (kerosine}, which every year accounts for almost 60% of cases, and traditional African medicines accounting for up to 20% of cases per year. With the development of an academic f a c i l i t y , the m o r t a l i t y rate has dropped from 7% in 1981 to 1.q% in 1988. Paraffin poisoning accounted for a quarter and traditional medicines for half of the fatalities. Deliberate self-poisoning is uncommon, accounting for less than 20% of adult cases. In view of the data, the first world concept of a toxicology centre geared primarily towards drug identification and management of drug poisoning currently appears to have a low priority. Our priorities appear to be the following: Firstly, in the longterm, socio-economic development would reduce the need for paraffin as an energy source. In the interim education of the public with regards to safe use and storage of paraffin is essential. Secondly the issue of m o r t a l i t y and morbidity due to traditional medicines need to be addressed. Rigid legislation does not seem to be a solution when dealing with deep-seated cultural beliefs. Liason with local traditional healers has shown that they are concerned people and are prepared to cooperate with health workers in identification of unknown medicines and eleminating dangerous practices. In view of a trend for poisoning with traditional medicine to decrease and drug poisonings and deliberate self-poisoning to increase, we might need to revise our approach in future. This work is sponsored by the S.A. Medical Research Council. Department of Pharmacology and Therapeutics, P.O. Medunsa 0204, South Africa.

ANTIBODIES FROM PATIENTS WITH H A LO TH A N E HEPATITIS RECOGNISE TRIFLUOROACETYLATED PROTEINS OF THE LUMEN OF THE ENDOPLASMIC RETICULUM J.G. Kenna. J.L. Martin, B. Martin. H. Satoh and L.R, Pohl Current evidence suggests that halothane hepatitis may arise in s u s c e p t i b l e i n d i v i d u a l s as a consequence of i mm u n e sensitisation to trifluoroacetylated liver mierosomal proteins, of molecular mass 100, 76, 59, 57 and 54 kDa as determined by SDS-polyaerylamide gel eleetrophoresis and immunoblotting. The TFA-labelled proteins are expressed in livers of halothane treated rabbits, rats and humans and are produced as a consequence of metabolism of halothane by eytoehrome(s) P450 to TFA-halide. It has been determined that the 100, 76, 59 and 57 kDa antigens are peripheral and not integral membrane proteins, in that they can be solubilized by washing microsomal fractions of rats treated ip with halothane (at 10 mmol/kg, 18 hr before sacrifice) with 0.1% sodium dcoxycholate or 0.1 M sodium carbonate. The solubilized 57 kDa antigen has been p u r i f i e d to homoge ne i t y using c o n v e n t i o n a l b i o c h e m i c a l methods and the 59 kDa antigen has been purified by ant-TFA a f f i n i t y c h r o m a t o g r a p h y . N - t e r m i n a l sequence a n a l y s i s revealed that the antigens correspond to proteins which are known to be r e s i d e n t in the lumen of the e n d o p l a s m i e reticulum, namely protein disulphide isomerase and liver microsomal earboxyleherase, respectively. The active site of cytochrome P-450 is located on the cytoplasmic face of the membrane of the endoplasmie reticulum. Thus it appears that generation o1" the antigens involves diffusion of the highly reactive TFA-halide through the lipid bilayer. L a b o r a t o r y of Chemical Pharmacology, NHLBI, C l i n i c a l Neuroseienee Branch, NIMH, NIH, Bethesda, MD 20892, USA and Department of Pharmacology and Toxicology, St. Mary's Hospital Medical School, London W2 IPG, UK.

OP 35.03

OP 35.05

ASSESSMENT AND QUANTIFICATION OF THE REACTIVE METABOLITE(S) OF ACETYLHYDRAZINE BY LASER MAGNETIC RESONANCE SPECTROMETRY (LMRS) K. M6rike, M. Eichelbaum, M. Koch*, and W. Urban*

ANOREXIGENIC PATIENTS WITH Y. Okabe, K. Masuno** and

leonlazid (INH) hepatotoxicity is e major side effect of this drug during treatment of tuberculosis. Acetylhydrazine (AcHz) has been identified as the metabolite of isoniazid responsible for hepatotoxicity. Based on studies with [14C]-AcHz it has been proposed that AcHz is activated to a hepatotoxic metabolite involving the formation of N-hydroxy-AcHz in a cytochrome P-450 dependent reaction. This metabolite rearranges under the loss of water to a diazene which in turn decomposes to a reactive acetylating species, I.e. aCetyl radical or cation. Provided that this assumption is correct, N2 should be formed In amounts similar to CO 2. In order to test this hypothesis we studied 15N~ and 14CO2 expiration following i.p. administration of [15N2]-[1"4C]-AcHz in the rat. Control animals were compared with rats pretreated with phenobarbitone (Phb) alone or together with cobeltoue chloride (COCI2), i.e. known modulators of cytochrome P-450. LMRS, a new specific and highly sensitive techn que, was used to measure 15N2 exhalation. 2.4% of the dose was recovered as N2 in the control group. No substantial change was observed after Phb pretreatment (2.6%), whereas CeCI 2 caused a pronounced decrease in N2 formation (1,3%). 14C02 was recovered at considerably higher yields (18.3% in controls, 17.5% after Phb, and 15.6% after CoCI2 pretreatment). In contrast to 15N2 exhalation, no clear difference in 14CO2 expiration was observed between Phb and CoCI2 pretreated animals. If N2 exhalation reflects the fraction of the dose metabolised to the reactive Intermediate(s) the much higher proportion of 14CO2 exhalation indicates that 14(202 is generated not only from acetyldiazene but also by amidolytic cleavage. Therefore, 14CO2 exhalation' is not a specific indicator of AcHz metabolic activation. N2-releasing processes can be specifically and sensitively monitored by LMRS.Supported by Robert-Bosch-Stiftung, Dr.Robert-Pfleger-Stiftung, and Landesamt f0r Forschung Nordrhein-Westfalen.Dr. Margarete Fischer-Bosch-Institut far IGinische Pharmakologie, Auerbachstr. 112, 19-7000 Stuttgart 50 and *Institut far Angewandte Physik der UniversitdtBonn, WegelerSO'. 8~1)-5300Bonn.

Anorexia, accompanied with progressive weight loss and cachexia, is a c o m m o n symptom in c a n c e r patients. The polypeptide, toxohormone-L, which was e x t r a c t e d f r o m a s c i t e s of p a t i e n t s w i t h h e p a t o m a , has been d i r e c t l y s h o w n to a c c e l e r a t e l i p o l y s i s in the adipose tissue and decrease food intake (Masuno et al. 1984). The p r e s e n t s t u d y a i m e d to c l a r i f y the c e n t r a l and s p e c i f i c e f f e c t on food i n t a k e in rats. Toxohormone-L was i s o l a t e d by a m m o n i u m sulfate precipitation and chromatofocusing column chromatographies. It s e d i m e n t e d as a s i n g l e p e a k w i t h a c o e f f i c i e n t of 4.81 s. M a t u r e m a l e W i s t a r King A rats, 2 6 0 - 3 2 0 g, w e r e h o u s e d and t e s t e d in a room illuminated from 0800-2000 hr and maintained at 21~I~ and 55• humidity. B o t h food and w a t e r intake were s i g n i f i c a n t l y suppressed on t h e f i [ s t d a y a f t e r i n f u s i o n of t o x o h o r m o n e - L , an o p t i m u m d o s e of 10 Hg/rat, into the third cerebroventrlcle. Decreased food intake was m a i n l y derived from reduction of meal size. The effects were c o m p l e t e l y recovered within 24 hr after infusion. Ambulation was not affected. Nons p e c i f i c and n o n - r e g u l a t o r y behavior including a t a x i a and s t u p o r w e r e not o b s e r v e d at any d o s e s tested. The suppressive effect on rat feeding seems to d e p e n d on a c c e l e r a t i o n of n e u r o n a l a c t i v i t y in the ventromedial hypothalamus, since decreasing meal size implies earlier cessation of meal, indicating full satiation. Toxohormone-L is c e r t a i n l y an i m p o r t a n t p e p t i d e to p r o d u c e c a c h e x i a in p a t i e n t s with cancers. Dept. of P e d i a t r i c s a n d *ist Dept. of I n t e r n a l M e d i c i n e , K y u s h u Univ. H i g a s h i - k u , F u k u o k a , 812 Japan. **Dept. of Biochemistry, Ehime Univ.

EFFECT OF T O X O H O R M O N E - L ISOLATED FROM HEPATOMA Ueda, T. S a k a t a * , K. F u j l m o t o * , H. H. Okuda**

A 98

OP 35.06

OP 35.08

LONG-TERM LITHIUM-TREATED PATIENTS AND THE RENA FUNCTIONS : A PROSPECTIVE STUDY J.M. DANION, J.L. IMBS, M. WELSCH, M. SCHMIDT, L. SINGER A prospective study of the evolution of the creatinine," urea and lithium clearances was carried out in 202 long-term lithium-treated patients. Lithium carbonate was administered 3 times a day, and plasma lithium levels were maintained between 0.5 and 1.0 mmol/l. A preliminary analysis included 150 patients, checked after an average of 5 years treatment (range 0.5-11 years). i) No significant modifications in renal clearances were observed in these 150 patients as a whole. 2) 12 of them were suffering from a mild renal insufficiency before lithium treatment. After an average of 5 years treatment, their renal functions did not worsen. 3) A mild to moderate renal failure was observed in 14 out of the 150 patients. In 3 patients, no factor except lithium treatment could have been involved ; 6 others were suffering from a somatic disease such as hypertension, chronic urinary infections, diabetes, likely to favour a renal insufficiency.

CLINICAL PHARMACOLOGY AND TOLERABILITY OF MDL 73.147EF [MDL] A SELECTIVE 5-HTB RECEPTOR ANTAGONIST

Departement de Psyehiatrie, Centre Hospitalier Universitaire, 67005 STRASBOURG Cedex- France. Centre R~gional de Pharmacovigilanee Alsace, Unit@ de Pharmacologic Clinique, Institut de Pharmacologic, Facult@ de M@decine, 67000 STRASBOURG Cedex- France.

C. Hinze, J. Hardenberg, J.M. 0twin MDL 73.147EF (iH-Indole-3-carboxylic acid, trans-octahydro-3 oxo-2,6-methano-2H-quinolizin-8-yl ester, methane sulphonate) is a selective antagonist at the 5-HTR receptor. The compound is being developed for the treatment of chemotherapy-induced nausea and vomiting. The present study was established to determine the tolerabilty of MDL, its effect on the flare-E~sp0nse to intradermally injected 5-HT (0.04 ml, 4 x i0 WM) and on prolactin levels. 8 groups of 6 healthy male volunteers received single i.v. doses of MDL (i to 30 mg) (one volunteer randomised within each group to receive placebo) in a double-blind manner. Effects on vital signs, routine laboratory tests, ECG, subjective selfrating (EWL-N), reported adverse events , prolactin levels and the flare-response to intradermal 5-HT were monitored at intervals over 2~ hrs. No drug- or doserelated changes were found for vital signs, routine laboratory values, ECO, EWL-N or serum prolactin-levels. Tolerability was good. Unwanted effects included headache and nausea. One subject (MDL 2.0 mg~ developed a maculo-papulous exanthema. The flare-response was significantly inhibited by 40 to 60 % following I0 to 30 mg of MDL. The effect became apparent at 5 mins with a duration of i hr at i0 and 20 mg to at least 4 hrs at 30 mg. These results indicate that doses of 1 to 30 mg of MDL are well tolerated and that doses from i0 to 50 mg produce significant and selective 5-HT 3 receptor antagonism in man. Merrell Dew Research Institute, Dept. of Clin. Res., 2, rue de Stockholm, F-67000 Strasbourg, France

OP 35.07

OP 36.01

EFFECT OF WHOLE BODY EXPOSURE TO GAMMA RADIATION ON SMOOTH MUSCLE SENSITIVITY TO SOME MEDIATORS M. E I - G h a z a l y ~ F. E i - B a t r a w y * ~ A. S. A t t i a * * ~

THE EFFECT OF SULINDAC ON COUGH ASSOCIATED WITH ACE-I THERAPY AND ON IDIOPATHIC DRY COUGH J.R. M c E w a n , N.B. C h o u d r y * a n d R.W. F u l l e r I d i o p a t h i c d r y c o u g h (IDC) a n d c o u g h d u e t o a n g i o t e n s i n c o n v e r t i n g e n z y m e i n h i b i t o r (ACE-I) t h e r a p y a r e a s s o c i a t e d w i t h a n i n c r e a s e in t h e s e n s i t i v i t y of t h e c o u g h reflex. W ~ h a v e o b s e r v e d p r e v i o u s l y t h a t i n h a l e d PGE 2 w ~ l l i n c r e a s e t h e s e n s i t i v i t y of t h e c o u g h reflex. W e h a v e s t u d i e d t h e e f f e c t s of s u l i n d a c (S), a c y c l o o x y g e n a s e i n h i b i t o r , on t h e c o u g h r e f l e x ~ n d c o u g h s y m p t o m s of 6 p a t i e n t s w i t h A C E - I c o u g h a n d 6 w i t h IDC. T h e c o u g h r e f l e x w a s t e s t e d b y c o u n t i n g t h e c o u g h s p r o d u c e d b y i n h a l a t i o n of c a p s a i c i n b e f o r e a n d a t t h e e n d of a w e e k of d a i l y t h e r a p y w i t h S 2 0 0 m g or p l a c e b o (P). C o u g h s y m p t o m s e v e r i t y w a s r e c o r d e d as a d a i l y s c o r e o f 0-20, a n d t o t a l l e d o v e r the w e e k to g i v e a c o u g h score. R e s u l t s a r e s h o w n as g e o m e t r i c m e a n (95% CI) d o s e s of c a p s a i c i n (nmol) p r o d u c i n g 5 o r m o r e c o u g h s (Ds). C o u g h s c o r e s a r e s h o w n as m e d i a n (range). R e s u l t s w e r e a n a l y s e d b y 2 - w a y analysis of variance. ~ for ACE-I cough patients was 0.89(0.25-3.16) before P and did not change significantly a f t e r P, 0 . 6 3 ( 0 . 2 8 1.39) or before S 1.26 (0.5-3.08) but was s i g n i f i c a n t l y h i g h e r at 4 . 0 1 (1.0-15.3) a f t e r S. D 5 of IDC p a t i e n t s s h o w e d no c h a n g e b e f o r e 0.89 (0.22-3.5) o r a f t e r P 1.4 (0.33-6.03) or b e f o r e 1.12 (0.26-4.90) o r a f t e r S 0.71 (0.243.31). C o u g h s c o r e s of A C E - I p a t i e n t s fell s i g n i f i c a n t l y f r o m 83 (25-104) O n P t o 52 (9-62) o n S b u t s c o r e s of IDC p a t i e n t s showed no s i g n i f i c a n t c h a n g e b e t w e e n P 41 (10-65) a n d S 30 (8-61). S r e d u c e s t h e s y m p t o m of c o u g h a n d the c o u g h r e f l e x s e n s i t i v i t y of p a t i e n t s w i t h A C E - I c o u g h b u t h a s no e f f e c t on IDC. PGs m a y b e i n v o l v e d in t h e p a t h o g e n e s i s of A C E - I cough. D e p t s of C l i n i c a l Pharmacology & Medicine*, R o y a l P o s t g r a d u a t e M e d i c a l School, London, U K

U.

MI

RO~s-Wdy-'Wfi~W.--T-Tq~h-E~-a-i~-~- ...............

I o n i z i n g radia~lo~s---k-h-6~--'~6-~-~fect b i o l o g i c a l t i s s u e s in v a r i o u s w a y s . P r e v i o u s e x p e r i m e n t s h a v e Showr, t h a t w h o l e b o d y e x p o s u r e to g a m m a r a d i a t i o n e n h a n c e s the r e l e a s e of m e d i a t o r s f r o m the l u n g s of s e n s i t i z e d g u i n e a - p i g s . T h e p r e s e n t s t u d y w a s c a r r i e d out to i n v e s t i g a t e w h e t h e r the i l e u m of the g u i n e a - p i g a n d the j e j u n u m a n d a o r t a of the r a b b i t w o u l d c h a n g e in sensitivity towards aeetyleholine~ serotonin~ histamin and/or noradrenaline after exposing the w h o l e a n i m a l s to a g a m m a r a d i a t i o n d o s e of 2 G r a y (Gy) f r o m a c o b a l t s o u r c e . T h e a n i m a l s w e r e s a c r i f i c e d a f t e r i~ 3 or 7 d a y s of i r r a d i ation, the respective tissues were isolated and their sensitivity towards different agonists w a s m e a s u r e d . A f t e r I day of e x p o s u r e , t h e r e w a s a s l i g h t i n c r e a s e in s e n s i t i v i t y of the ileum and jejunum towards aeetylcholine~ serot o n i n a n d h i s t a m i n e . H o w e v e r , the r e s p o n s e of the a o r t a to b o t h h i s t a m i n e a n d n o r a d r e n a l i n e w a s g r e a t l y d i m i n i s h e d . O n the t h i r d day a f t e r e x p o s u r e ~ t h e r e s p o n s e s of all the t i s s u e s tested towards their respective agonists were markedly exaggerated. The observed changes were r e v e r s i b l e s i n c e a f t e # 7 d a y s of e x p o s u r e ~ the t i s s u e s e n s i t i v i t i e s t e n d e d to be r e s t o r e d to normal. D e p a r t m e n t s of P h a r m a c o l o g y , N a t i o n a l C e n t r e for R a d i a t i o n R e s e a r c h a n d T e c h n o l o g y ~ * F a c u l t y of M e d i e i n e ~ C a i r o U n i v e r s i t y ~ a n d * * F a c u l t y of Pharmaey~ Cairo University, Cairo~ Egypt.

A 99

OP 36.02

OP 36.04

DOES~INARYN-METHYLIMIDAT_O~ ACEIIC ACID(N%MIAA) REFLECT LUNG PRODUCTION OF HISTAMINE? I.K. Taylor, G. O'Mallev, S. Murray, G,W. Taylor and R.W. Fuller The m a j o r physiological consequences of acute airflow obstruction in asthma are now thought to be principally related to perturbation of mast cell IgE receptors following allergen exposure. Mast cell activation in and around the airways results in degranulation and release of pro-inflammatory mediators, including histamine, which is a potent smooth muscle spasmogen. We have measured the urinary levels of the major urinary metabolite of histamine, N-methylimidazole acetic acid (N~-MIAA), to determine if this can be used as an indirect measure of lung mast cell histamine release following antigen challenge. Ten atopic, asymptomatic subjects, 7 F / 3 M age 1941 mean 28 years with normal serum biochemistry and on no concurrent anti-asthma therapy were studied. Baseline FEV 1 in all cases was >90% predicted when measured prior to allergen provocation. Allergen (either house dust mite or grass pollen) was administered via a breath activated dosimeter and urine collected for 4 hours post-challenge. A further control 24 hr urine collection was made not less than 2 weeks later in the same 10 subjects. Diet was unrestricted. N~'-M1AA was measured by gas chromatography negative ion chemical ionisation mass spectrometry,. It was corrected for urinary creatinine (Cr). " All subjects exhibited an early reaction with mean maximum fall in FEV 1 within 60 min of challenge of 43.3 -+ 4.6% (mean -+ SEM % change from baseline values). By 4 hr, 5 subjects had returned to baseline values; in the remainder, FEV 1 was still between 319% below baseline values. Urinary NZ-MIAA following challenge was 273.9 _+ 20.8 ,ug/mmol Cr vs 283.1 -+ 24.6 in the 24 hr collections and there was no significant correlation between N r - M I A A and the magnitude of the early airflow obstruction. We conclude that urinary measurements of N r - M I A A are therefore not an accurate reflection of mast cell histamine release from the lung following antigen challenge, and that production from the lung is insufficient to perturb total body N r - M I A A production from other endogenous sites. We are currently evaluating another u r i n a r y histamine metabolite, Nr -methylhistamine. Department of Clinical Pharmacology, Royal Postgraduate Medical School, Ducane Road, London W I 2 0 N N , U K

C O M P A R I S O N O F T H E B R O N C H O D I I A T I N G EFFBCTS O~ F E N O T E R O L HCl / B E R O T E C + / A N D I P R A T R O P I U ~ BROM I D E /ATROVENT*/, IN PATIENTS WITH D I F F E R E N T D E G R E E 0F P A T H O L O G Y O F RESiIRATION. Z. Votava The aim was to compare b r o n c h o d i l a t i n g effect o f b e t a g - s y m p a t h o m i m e t i c drug fenoterol, and a n t i c h o l i n e r g i c drug ipratropium, in patients w i t h different degree o f o b s t r u c t i v e qr restr i c t i v e pulmonary disease, and h e a l t h ~ persons. 171 persons were d i v i d e d in 8 groups, "accordin g to the l o w e r i n g of t h e i r FEV I and FVC values. Both drugs w e r e g i v e n in two puTfs in i m i n u te interval, and patients w e r e t e s t e d in FlowV o l u m e forced e x p i r a t i o n before and 30 m i n u t e s a f t e r drug. ERICH J A E G E R P o l y g r a p h with comput i n g e v a l u a t i o n was used. Following valueswere e v a l u a t e d in p e r c e n t a g e o f change between first and second test: FVC, FEV1, ~ E F 25, 50, 75 ~, PEF. Both drugs w e r e g i v e n twice in random sequence, p a i r T-Student test was u s e d for e v a l u a t i o n of results. sults: Both drugs evoked s t a t i s t i c a l signileant b r o n c h o d i l a t a t i o n in patients w i t h obs t r i c t i v e respiration. F e n o t e r o l was m o r e effective, e s p e c i a l l y in p a t i e n t s w i t h h i g h e r degree of o b s t r u c t i o n . In Patients w i t h restrictive lung disease and in h e a l t h y persons, both drugs w e r e without evident b r o n c h o d i l a ring effect. No side-effects /Tremor, tachycardia/ w e r e observed. Conclusions: Fenoterol is more effective in sev e r e obstruction, ipratropium in m i l d o b s t r u c t i o n with r e s t r i c t i o n /chronic bronchitis/. CS-10100 P~.aBa i0, ulice ~apkG 21

~g

OP 36.03

OP 36.05

EFFECT OF TEl- AND TETRACYCLIC COMPOUNDS ON HISTAMINE-INDUCED BRONCHOCONSTRICTION IN HEALTHY VOLUNTEERS. L. Firkusny, K. H. Antonin, and F. R. Bieck Tri- and tetracyclic c o m p o u n d s ( T C ) s h 0 w d i f f e r ent affinities to Hi-receptors in vitro (Brain Hes. 304, i-7, 1984)~ Therefore, the in vivo H~-antagonism of doxepin (Aponal@)~ maprotiline (s benzoctamine (Tacitin | and the new antidepressant levoprotiline was investigated by means of histamine-induced bronchoconstrietion (HIB) in a total of 28 healthy volunteers. The volunteers (n) were given therapeutically effective single oral doses of 50 mg doxepin (i0), 50 mg maprotiline (ii), I0 mg benzoetamine (4), o r 7 5 mg levoprotiline (5). The tests were performed without, and 1 to 2 h after medication. The results of HIB tests a r e e x p r e s s e d as histamine concentration I~mol/L] causing a 20~ decrease (PC20) in forced expiratory volume in one second. Results: PC20 , median Prevalue Treatment Doxepin 69 >208 Maprotiline 55 >312 Benzoctamine 74 87 Levoprotiline 72 i01 In volunteers treated with doxepin and maprotiline, histamine concentrations up to 208 and 312 mmol/L did not induce HIB. Benzoctamine and levoprotiline caused a slight shift of PC to 2O the right. Conclusion: The results show that clinically well tolerated doses of TC demonstrate different H -antagonistic effects in man. These effects s~em to correlate with the in vitro affinity to Hl-receptors. Human Pharmacology Institute, CIBA-GEIGY GmhH, Waldh~rnlestr. 22, D-7400 T~bingen, FEG

EFFECT OF BUDESONIDE ON THE BRONCHIAL HYPERRESPONSIVENESS TO BOTH DIRECT AND INDIRECT ACTING SPASMOGENS R.W. Fuller, N.B. Choudry and *G. Eriksson Inhaled glucocorticosteroids consistently reduce the b r o n c h o c o n s t r i c t o r responses to inhaled, directly acting, spasmogens through u n d e t e r m i n e d mechanisms. The aim of this study was to determine the magnitude of response of budesonide on the b r o n c h o c o n s t r i c t o r response of both directly (histamine) and indirectly (bradykinin) acting spasmogen. Ten patients (6 M/4 F, 18-45 years) with mild asthma (prediced FEV I of 89.5 • 4%) took part. The provocation dose of b r a d y k i n i n and histamine causing a 35% fall in sGaw (PD35) was determined before and after 3 weeks treatment with 1.2 mg b u d e s o n i d e or placebo per day. Twice daily PEF and symptom score were also recorded. Neither treatment altered the baseline FEV I or sGaw. However, there was a significant difference in the PD35 to both h i s t a m i n e and bradykinin after budesonide compared to placebo. Mean (95% CI) PD35 histamine was 0.4 (0.2 to 0.8) afte r placebo and 1.3 (0.7 to 2.5) Nmol after budesonide (p < 0 . 0 1 ) . Corresponding figures for PD35 b r a d y k i n i n were 0.i (0.3 to 0.30) and 0.4 (0.i to 1.4) ~mol (p < 0.01). Diary recordings showed a significant increase in PEF after active treatment. Therefore budesonide reduces the response to both direct and indirect stimuli to the same extent (2.0 to 2.1 doubling dilutions, respectively) demonstrating that the effect of inhaled steroids must be on a m e c h a n i s m central to both spasmogens. Department of Clinical Pharmacology, Royal Postgraduate Medical School, London W I 2 0 N N and *A B Draco, Box 34, S-221 00 Lund, Sweden.

A 100

OP 36.06

OP 37.02

A C U T E AND LONG TERM A M I L O R I D E I N H A L A T I O N AND ITS ACTION ON R E S P I R A T O R Y EPITHELIUM IN CYSTIC FIBROSIS LUNG DISEASE: A NEW CONCEPT IN CYSTIC FIBROSISTHERAPY Ernst M. Ago *. Malcolm Kina *. Dieter K6hler ** and He[nriqh Matthys Cystic fibrosis (CF) is the most common inherited fatal disorder among Caucasians, where pulmonary complications determine the fate of the patients. Bronchial mucus in CF contains more potassium and less sodium, which is suggested to be due to increased sodium absorption, resulting in a reduced airway water content. In order to augment the sodium content of their bronchial secretions and enhance lung clearance, our CF patients inhaled amiloride, a sodium transport blocker. To assess bronchial clearance, 99mTc labeled hardened erythrecytes were inhaled from a special device that ensured their monodispersity. Mucociliary clearance (MC) and cough clearance (CC) were determined by following the movement of particles with a gamma camera over a period of 60 min. Before and after each investigation PFT and RR were measured to detect pulmonary and systemic side effects. Sputum rheology (viscoelasticity) was examined using the filancemeter. We examined 23 CF patients after acute placebo (0.9% NaCI solution) and amiloride (10.3 M) inhalation. Six of the patients also underwent a 3 week trial of amitoride inhalation therapy versus placebo. Acute MC in CF increased significantly (p<0.001) after amiloride inhalation (bronchial deposition 0.07 mg amiloride) compared to saline control. The increase was even greater after 30 min. than after 60 rain. CC also increased (p<0.005) but not as much as MC. After 3 weeks of placebo inhalation the clearance values did not change, but after 3 weeks of amiloride inhalation (2 times a day) the acute amiloride and NaCI clearance increased significantly (p<0.01), exceeding the values of the acute experiment, Sputum viscoelasticity decreased significantly after amiloride inhalation. We conclude that 1) amiloride single dose or long-term inhalation is able to increase MC and CC in CF via sodium blockade and changed viscoelastic sputum properties, 2) the effect of 10.3 M amiloride inhalation on MC lasts at least 40 min, and 3) acute and long-term amiloride aerosol therapy showed no side effects. These results indicate that further clinical experiments with even longer term amiloride application in CF are justified. This is the first line of evidence that an inhaled diuretic drug, such as amiloride, is able to enhance mucociliary clearance and cough 'clearance in cystic fibrosis patients via modifying mucus secretions in the airways. (Supported by the Ministry for Science and Art of the Federal State of Baden-Wentemberg and by the Canadian Cystic Fibrosis Foundation) * Pulmonary Defense Group, Univ. of Alberta, Edmonton T6G 2C2, Canada. ** Fachkrankenhaus Kloeter Grafscha~, 5948 Schmallenberg 11, FRG. *** Div. of Pulmonary Dis., Dept.of Internal Medicine, Univ.of Freiburg, FRG.

AGE AND THE PHARMACODYNAMICS A~D PHARMACOKINETICS OF BENAZEPRIL N~J, M~cdQ~ald, H,~, Elliott, C,A, HQvie, J. HarriKan and J,L, Reid. Benazepril is a new long-acting ACE inhibitor which appears to be less dependent than the currently available agents on renal elimination, such that dose reduction in the elderly may not be necessary. To investigate the pharmacokinetics and pharmacodynamics of benazepril in the elderly, eighteen healthy normotenslves (9 young and 9 elderly) particpated in a double blind, placebo-controlled comparison of benazepril (10 mg) and enalapril (10 mg). The area under the drug concentration time curve (AUCo_ ) was greater in the elderly, by 1105 after enalapril and by 40% after benazepril. Protein-binding of both drugs was significantly reduced in the elderly group: from 91.8 • 1.6 to 88.6 • 2.3 for benazeprilat and from 22.4 • 9.6 to 10.7 ~ 8.5 for enalaprilat. Both drugs produced long-lasting plasma ACE inhibition, with over 40% inhibition at 24 hours. Fitting plasma drug concentration and ACE inhibition data to a sigmoid Emax model in each subject revealed no difference in IC50 between enalapril and benazepril and no age-related differences in the sensitivity of plasma ACE inhibition. Compared to placebo, both drugs caused significant blood pressure reductions which tended to be greater in the elderly. Thus, despite relatively greater kinetic differences after enalapril in the elderly the hypotensive responses to both drugs were comparable. One possible explanation is that this reflects a differential effect on protein binding: an increase of 37% in free fraction in the elderly with benazepril, compared to 155 with enalapril. The clinical relevance of these differences remains to be established in hypertensive patients. Department of Materia Medica~ Stobhill General Hospital, Glasgow, G21 3UW.

OP 37.01

OP 37.03

EFFECT OF CAPTOPRIL ON THALLIUM-201 MYOCARDIAL PERFUSION IN SYSTEMIC SCLEROSIS. B. Amor, A. Kahan, C.J. Menk@s, J.Y. Devaux, S. Weber, A. Venot, G. Strauch. Patients with systemic sclerosis often have thallium-201 myocardial perfusion abnormalities which may be due to a disturbance of the coronary microcirculation. We assessed the long-term effect of captopril (75 to 150 mg per day) on thaIlium-201 myocardial perfusion in 12 normotensive patients with systemic sclerosis. Thallium-201 single-photon-emission computerized tomography was performed at baseline and after one year treatment with captopril. In each patient, the left myocardium was divided into 9 segments ; each segment was graded as 2, 1.5, 1, 0.5, 0 (zero represents no activity) by 3 independent observers ; thallium defects were defined as mean scores of less than 1.5 ; a global score was obtained by summing the mean scores of the 9 segments. Captopril significantly decreased the mean (+ SD) number of segments with thallium defects (6.5 ~ 1.9 at baseline and 4.4 + 2.7 after one year treatment with captopril (p < 0.02)) and increased the mean global score (9.6 + 1.7 at baseline and 11.4 + 2.1 after captopril (p <--0.05)). In a control group of 8 normotensive patients with systemic sclerosis who did not receive captopril, no significant modification in thallium results occurred. Side-effects with captopril included hypotension (6 patients), taste disturbances (I patient), and skin rash (1 patient), and subsided when the dosage was reduced. These results demonstrate that captopril improves thallium-201 myocardial perfusion defects in patients with systemic sclerosis and therefore may have a beneficial effect on scleroderma myocardial disease. Departments of Rheumatology and Cardiology, and IRT-ECLIMED, H6pital Cochin, 27 rue Fg St Jacques, 75014, Paris, France.

PERSISTENT ANTIHYPERTENSIVE EFFECT OF ALACEPRIL IN PATIENTS WITH ESSENTIAL HYPERTENSION. A.Ikeda,H.Shionoiri,K.Sugimoto,K.Minamisawa,S.Ueda,Y.Abe, T.Ebina and E.Gotoh. A l a c e p r i l ( A L A , MW;406.5) was r e c e n t l y developed as a new o r a l l y - a c t i v e a n g i o t e n s i n c o n v e r t i n g enzyme(ACE) i n h i b i t o r w i t h long l a s t i n g a n t i h y p e r t e n s i v e e f f e c t . ALA is dea c e t y l a t e d to deacetyl-ALA and is f u r t h e r converted to c a p t o p r i l ( C A P , MW;217.3). We compared a n t i h y p e r t e n s i v e e f f e c t I A E ) and i n h i b i t i o n o f plasma ACE a c t i v i t y a f t e r oral s i n g l e dose o f ALA(25mg) w i t h those a f t e r CAP(25mg) in 6 p a t i e n t s w i t h mild or moderate e s s e n t i a l hypertension. The blood pressure values of the ALA and the CAP group before the drug a d m i n i s t r a t i o n were as f o l l o w s , SBP;160.3 •177 DBP;99.3•177 r e s p e c t i v e l y . No s i g n i f i c a n t d i f f e r e n c e was observed in the p r e t r e a t m e n t blood pressure between the ALA and CAP group. In the ALA group,BP decreased from 160.3•177 1.5mmHg to minimum l e v e l s of 132.8~1.8/81.0• at 4 hrs, and showed a s i g n i f i c a n t f a l l up to 12 hrs in SBP and 24 hrs in DBP a f t e r the drug a d m i n i s t r a t i o n . On the o t h e r hand, in the CAP group,BP decreased from 161.3• 96.3• to minimum l e v e l s o f 136.8•177 at 4 hrs, and showed a s i g n i f i c a n t f a l l up to 8 hrs in SBP and 6 hrs in DBP. Plasma ACE a c t i v i t y before the administ r a t i o n of ALA and CAP was 28.7• and 27.6• , r e s p e c t i v e l y . In the ALA group, % i n h i b i t i o n o f ACE act i v i t y showed a peak of 81.1• at 2 hrs w i t h a s i g n i f i cant d i f f e r e n c e up to 24 hrs a f t e r a d m i n i s t r a t i o n . In the CAP group, a peak o f 88.3• was a t t a i n e d at i hr and a s i g n i f i c a n t i n h i b i t i o n was also found up to 24 hrs a f t e r a d m i n i s t r a t i o n . The time to reach the maximum i n h i b i t i o n was 1 hr l a t e r in the ALA group than in the CAP group. Duration o f AE was longer in the ALA group than t h a t in the CAP group. We consider t h a t t h i s r e s u l t s may be due to i t s m e t a b o l i t e s . I n t e r n a l Medicine 2, Yokohama C i t y U n i v e r s i t y , 3-46 Urafune-cho, Minami-ku, Yokohama 232, Japan

A 101

OP 37.04

OP 37.06

P E P T I D E ACTION AND LOCAL ACE INHIBITION IN FOREARM RESISTANCE VESSELS IN MAN J.R. Cockcroft. N. Benjamin and D.~I, Webb A n g i o t e n s i n c o n v e r t i n g e n z y m e (ACE), p r e s e n t on endothelial cells as well as in blood, catalyses the release of c a r b o x y - t e r m i n a l dipeptides, b o t h to g e n e r a t e active hormones (angiotensin II [ANG II]) and metabolise others ( b r a d y k i n i n [BK]). Its action m a y t h u s be i m p o r t a n t in regulating local responses to vasoactive peptides. This was investigated by studying the effect of the ACE inhibitor enalaprilat (5~g/min) on the actions of ANG I and II, BK, s u b s t a n c e P [SP] a n d atrial n a t r i u r e t i c peptide [ANP] on h u m a n resistance vessels, with all drugs infused into the left brachial a r t e r y of h e a l t h y subjects. Forearm blood flow (FBF) was m e a s u r e d by venous occlusion p l e t h y s m o g r a p h y coupled with mercury-in-silastic s t r a i n gauges. E n a l a p r i l a t had no effect on FBF when given alone for 10 rain (n=8). ANG II produced a dose-related reduction of F B F in the infused arm, with 5pmol/min approximately h a l v i n g flow (n=6). This response was unaffected by coinfusion of e n a l a p r i l a t (n=6). In the same subjects the molar potency of ANG I was only 40% of t h a t to ANG II, and was reduced 100-fold by co-infusion of enilaprilat. BK produced a dose-related increase in FBF in the infused arm, w i t h 3 0 p m o l / m i n a p p r o x i m a t e l y d o u b l i n g flow (n=6). E n a l a p r i l a t significantly potentiated the response to BK (n=6; p,0.001). Local ACE i n h i b i t i o n h a d no effect on responses to either SP or ANP. We c o n c l u d e t h a t enalaprilat both attenuates vasoconstriction to A N G I, and enhances vasodilatation to BK, b u t has no effect no responses to ANG II, SP or ANP~ The absence of a n effect of e n a l a p r i l a t on r e s t i n g F B F suggests t h a t in these circumstances n e i t h e r circulating ANG I nor BK influence these resistance vessels. Dept. of Clinical Pharmacology, RPMS, London W12 ONN.

TIME COURSE OF TIIEI~B4DDYI~%MICF~FFICACYOFNITROGLYCERIN RELEASED D I S C O N T I N O U S L Y F R O M A T R A N S D E I ~ M A L ~ E U T I C SYSTEm4

A. wie~and, K.H. Bauer, R. Bonn, D. Trenk and E. J~hnchen The constant release of nitroglycerin from transdermal systems is thought to produce hemodynamic and antianginal tolerance as early as 8 to 12 hours after application. Thus, we investigated if or to what extent the hemodynamic activity of nitroglycerin is attenuated after repeated administration of a discontinuous releasing transdermal system to i0 healthy volunteers. After one day of placebo application the subjects received one verum patch per day for 4 days. During the entire study period the plasma concentrations of nitroglycerin and its metabolites as well as the following hemodynamic parameters were measured: a/b-ratio of the fingerpulse curve, supine and orthostatlc blood pressure, and heart rate. The mean o~erall release of nitroglycerin from the transdermal systems was 14.5 mg/24 h, whereby about 70 % was released during the first 12 hours. The maximum nitroglycerin concentrations were 638 • 287 pg/ml on day ] and 1203 + 567 pg/ml on day 4. The area under the a/b-ratio of the fin~e~pulse - ti,~ curve increased by 34 • 5 % and 17 • 2 % on the first and fourth day, respectively. Orthostatic systolic blood pressure decreased by 19 • 14 mmHg and heart rate increased by 19 • 12 bpm on the first day. These figures were 14 • 7 rmllHgand 15 • 13 bpm on the 4. day. The effect of sublingual nitroglycerin (0.8 mg) on the a/b-ratio of the fingerpulse curve was diminished by 46.8 • 17.8 % at the end of the first treatment day and by 61.9 • 21.7 % at the end of the 4. day (one hour after removal of the last patch). The effect was restored about 12 hours following removal of the patches. Thus, phasic release of nitroglcerin leads to an attenuation of the hemodynamic effects of about 50% after 4 days of continuous treatment. Abteilung f~r Klinische Pharmakologie, Rehabilitationszentrum, S0dring 15, D-7812 Bad Krozingen

OP 37.05

OP 37.07

METHIONINE REVERSE TOLERANCE TO TRANSDERMAL NITROGLYCERIN Richard J. Katz, M.D., Alan G. W a s ~ , M.D., Warren Levy, M.D. George Washington University, Washington, D.C.

NITRATE TOLERANCEDESPITEHIGH PLASMACONCENTPJ%TIONSAND 12 HOURLYTREATMENTWITH ISO-5-HONONITPJ%TE. P. Deedwania, U. Thadani and the Iso-5MN Study Group Tolerance to oral nitrates during long-term therapy remains a major concern. In t h i s double-blind, randomized study we evaluated the effects of two different doses of Iso-5MN (20 and 40mg) given twice daily, 12 hrs apart in 43 patients(pts) with chronic stable angina. All pts were nitrate responders showing an increase in exercise(Ex) duration by 15% or more with 0.4mg sublingual nitroglycerine. After i wk on placebo, pts were randomly assigned to 20 o r 40mg Iso-5MN or placebo for I wk period each. Treadmill Ex test (ETT) was performed at 2 and 10 hrs post dosing at the end of each treatment period. Mean plasma concentration(PC), standing systolic BP(SBP), total exercise time(TExt) to onset of moderately severe angina and degree of ST during ETT at 2 and 10 hrs were: Placebo Iso5MN (20mg) IsoSMN(40mg) 2hr lOhr 2hr 10hr 2hr 10hr PC(ng/ml) 0 0 426 221 831 286 SBP(mmHg) 131 131 120# 136 119# 132 TExt(min) 6 . 1 8 5.74 6.77# 5.80 6.95# 5.71 ST +(mm) 1 . 7 4 1.79 1.74 1.79 1.70 1.85 (# = p<.00l compared to placebo) Conclusions: The above data show that (i) treatment with Iso-5-MN improves exercise capacity and reduces resting SBP at 2 hrs but not at 10 hrs post dose during 12 hourly administration, and 2) the lack of improvement in total exercise time and return of SBP to baseline values at 10 hrs post dose despite plasma concentrations higher than usual therapeutic level (>100 ng/ml) indicates nitrate tolerance during twice daily therapy with Iso-5-Mononitrate. VAMC/UCSF School of Medicine, 2615 E. Clinton Avenue, Fresno, California, 93703, U.S.A.

Depletion of sulfhydryl groups (SH) may contribute to nitroglycerin (RIG) tolerence following chronic exposure. We studied the ability of methionine (Meth), a SH donor, to potentiate the vasodilatory effects of NTG and reverse tolerance. The equilibrium technique to forearm plethysmography was used to measure venous tone (VT) pre and post a 0.4rag sublingual ~ bolus in 13 pts i) at baseline (base); 2) 2 hrs post 10mg NTG patch (NTP-2h) and 3) 74 hrs after continuous patch exposure (NTP-74h). Repeat measures were made following 5gins IV Meth at base (M-base) and 74hrs (M-74h). Forearm volumes were measured at 3OnTo Hg above cuff zero with results expressed as VT (cc/100cc arm; mean _+ S.D.): Base M-base NTP-2h NTP-74h M-74h Pre-NTG 2.58_+.9 2.56+.8 2.80~i 2.58+.9 2.67• Post-NTG 3.37_+1" 3.45~.9" 3.60/-_1. 3.01+.9" 3.53• % change 32• 37_+15+ 31_+13,* 16_+10 35_+14"* *]3<.001 vs.pre-NTG,+p<.02 vs.Base,**p<.001 vs.NTP-74h Methionine alone had no intrinsic vasodilatory action. VTchanges in response to N T G b o l u s w e r e attenuated at 74 hrs ([3<:.001vs. 2hrs). Methpote/]tiatedthe effect of N T G m o r e so at 74 hrs than at base (17.4% vs. 5.4%, P<.001) suggesting greater sulfhydryl donor effect in the attenuated state. Plasma volume expansion was suggested at 74 h r s v s 2 h r s b y a 3% fall in hematocrit (p<.01) and increase in weight (157 vs 155 ibs,p<.01). Conclusion: i) Meth potentiates the vasodilatory effects of NTG and reverses attenuation following chronic transder~al NTG exposure; 2) Plasma avolume expansion after prolonged NTG exposure may contribute to attenuation.

A 102

OP 37.08

OP 38.02

C A R D I O V A S C U L A R P R O F I L E S OF S E R T P ~ L I N E , FLUOXETINE, AMITRIPTYLINE, TRIMIPRAMINE, D O X E P I N E , I M I P R A M I N E , A N D P L A C E B O IN D E P R E S S I O N . E.C. D e s s a i n , C.M. Blatt, A.F. S c h a t z b e r g , M.P. Bird, and J.O. Cole. The s e r o t o n i n (5-HT) r e u p t a k e b l o c k e r s , f l u o x e t i n e and s e r t r a l i n e , are e f f e c t i v e a n t i d e p r e s s a n t s r e p o r t e d to h a v e no c a r d i o v a s c u l a r side effects. We r e c e n t l y r e p o r t e d the r e s u l t s of a m e t a - a n a l y s i s c o m p a r i n g the c a r d i o v a s c u lar p r o f i l e s of the a b o v e 5 - H T s e l e c t i v e a g e n t s w i t h the a d r e n e r g i c r e u p t a k e b l o c k e r i m i p r a m i n e , and the less s e l e c t i v e a t y p i c a l c o m p o u n d s amit r i p t y l i n e , t r i m i p r a m i n e , and doxepin. This a n a l y s i s d e m o n s t r a t e d that f l u o x e t i n e and sert r a l i n e did not p r o d u c e h y p o t e n s i v e r e a c t i o n s in p a t i e n t s w i t h d e p r e s s i o n a l t h o u g h there was an i n t r i g u i n g e l e v a t i o n in p u l s e rate in s e r t r a l i n e but not fluoxetine treated patients. Moreover, d e s p i t e p r e v i o u s r e ~ o r t s (Jarvik, LF., e~ al. 1983)*, b a s e l i n e p u l s e and s y s t o l i c o r t h o s t a t i c b l o o d p r e s s u r e f a i l e d to p r e d i c t b o t h the c l i n i cal e f f i c a c y of e i t h e r s e r t r a l i n e or a m i t r i p tyline. In the p r e s e n t f o l l o w - u p s t u d y m u l t i p l e reg r e s s i o n a n a l y s e s of a v a r i e t y of c a r d i o v a s c u l a r v a r i a b l e s w e r e e m p l o y e d in an a t t e m p t to d e v e l o p a m u l t i v a r i a t e t r e a t m e n t p r e d i c t o r index. Preliminary results indicate that cardiovascular r e s p o n s e to this d i v e r s e g r o u p of a n t i d e p r e s s a n t c o m p o u n d s w a s i n d e p e n d e n t of t h e i r P u t a t i v e a c t i o n s on c e n t r a l m o n a m i n e r g i c systems. H a r v a r d M e d i c a l S c h o o l and H a r v a r d S c h o o l of P u b l i c H e a l t h , L i n c o l n , M A 01773, U S A *Jarvik, LF, Read, SL, Mintz, J, and N e s h k e s , RE (1983): J. clin. P s y c h o p h a r m a c o l . , 3:368-372.

THE DEVELOPMENTOFCLINICALPHARMACOLOGY IN EUROPE F. SjCx]vist, M. Orme, J. Bircher, M. Bogaert, M.N.G. Dukes, M.Eichelbaum, L.F. Gram, H. H~ller, I. Lunde. G. Tognoni. Through the auspices of the World Health Organization (W.H.O) a questionnaire was sent to the Deans of all 375 medical schools in the W.H.O. European Region. Cc~pleted returns were received frcm 83% of schools in W. Europe and 63% of schools in E. Europe. (Results from U.S.S.R., Greece and Portugal were excluded because of a very low return rate). In W. Europe there ere 43 departments of clinical pharmacology (CP) with 33 divisions and 51 sections, but 39 schools have no formal grouping in CP. In Eastern Europe there are 15 departments of CP with 5 divisions and 12 sections while 9 schools have no formal grouping in CP. In W. Europe there are 334 individuals trained i n C H giving a mean figure of 2.0 per rnedical school. The largest group in any one country is the United Kingdom with 76 individuals trained in CP. In E. Europe there ere 90 individuals trained in CP with a mean figure of 2.3 per medical school. In W. European medical schools there are 208 established posts in CP (mean 1.3 per medical school) with 74 of these in the United Kingdc~. One medical school in ~ e d e n (with 2 departments of CP) has 13 posts in CP. However 15 schools in France, 9 schools in Italy, 9 schools in Spain and 19 schools in the FRG have no established posts in CP. In E. E[~opean medical schools there are 44 posts in CP (i.i per medical school). The largest number o f p o s t s ~ a medical school is in Poland with i0 but in Yugoslavia only one medical school has posts in CH. Much work is needed to increase the resources for CP in manyEuropeancountries. W.H.O. European Office, 8, Scherfigsweg, Copenhagen, Denmark.

OP 38.01

OP 38.03

THE TEACHING OF CLINICALPHARMACOLOGY IN EI/~OPEANMEDICAL SCHOOLS M. Orme, F. Sj~vist, J. Bircher, M.Bogaert. M.N.G. Dukes, M. Eichelba~n, L.F. Gram, H. H~ller, I. Lunde, G. Tog~oni. Through the auspices of the World Health Organization a questionnaire was sent to the Deans of all 375 medical schools in the W.H.O. European region. Completed returns were received frc~ 83% of schools in W. Europe (Results from Greece and Portugal are excluded because of a very low cc~pliance) and 63% of schools in E. Europe (U.S.S.R. results are excluded with only 8 returns out of 89 sent out). In W. Europe a mean of i01 (range 0-449) hours are devoted to the teaching of Pharmacology (P) with 28 hours (0-210) devoted to Clinical Pharmacology (CP) teaching. In E. Europe the figures are 124 (0-240) for hours of P teaching and 27.2 (0-90) for hours of CP teaching. While only one or two schools apparently have no teaching in P, the picture in CP is m u c h m o r e varied. In 39medical schools (24%) in W. Europe there is no teaching i n C H and in a further 20 there is less than 12 hours teaching. In particular there is no teaching of CP in Turkish medical schools and a ntmlber of schools in Austria (2), Belgiam (2), France (3), Italy (6), Spain (9) and FRG (i0) teach no CP. In E. Europe 7 schools (17%) teach no C P w h i l e a further 5 teach less than 12 hours. An average of 28 hours (range 0-750)is devoted to the teaching of therapeutics in W. European medical schools while in E. Europe only 7.5 hours (range 0-60) is devoted to therapeutics teaching. Pharmacology is almost entirely taught by trained pharmacologists but the teaching of clinical pharmacology is severely restricted by the lack of posts and trained individuals in CP. W.H.O. European Office, 8, Scherfigsweg, Copenhagen, Denmark.

PRESCRIPTION INFORMATION LEAFLETS: THEIR USE IN THE SETTING OF GENERAL PRACTICE C. F. George, S. Gibbs and W. E. Waters Many patients wish to have more information about medicines t~an they currently receive from doctors or pharmacists ~. We have developed generic l e a f l e t s for several groups of medicines_including non-steroidal a n t i inflammatory drugs (NSAIDs)z, 5-adrenoceptor antagonists and inhaled bronchodilators. We have evaluated the effects of these l e a f l e t s by comparing knowledge of and attitudes towards these medicines in 3 towns in which l e a f l e t s were distributed by either general practitioners or pharmacists with a control town in which no l e a f l e t s were d i s t r i b u t e d . Leaflets were d i s t r i b u t e d to 419 patients, whereas 300 patients in the control town received no written information. Patients were interviewed in their homesbetween 1, and 2 weeks after the medicine was dispensed. Patients who received leaflets were found to know more about their medicines, particularly the potential sideeffects, but there was no evidence that this led to spurious side-effects occurring. Much improved levels of satisfaction were recorded amongst patients who received

l e a f l e t s , p a r t i c u l a r l y those for NSAIDs (P
A 103

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OP 38.06

THE EFFECT OF INFORMATION - AN INTERVENTION STUDY ON ANTIBIOPIC PRESCRIBING AMONG PRIMARY HEALTH CARE PRACTITIONERS IN SRI LANKA I . Angunawela, V. Diwan, and G. Tomson Drug epidemiology is a new field of research in developing countries who often spend 30-50% of their health budget on drugs, antibiotics representing 30-40Z of this. There is a growing concern about misuse of antibiotics and drug resistance. There is a general lack of unbiased informats and scientific evidence of its effects. The aim of the study was to provide unbiased information and evaluate its effect on antibiotic prescribing. A randomized controlled trial with Primary Health Care Units allocated into two intervention (written I, written + verbal II information) and one control group was conducted. Prescriber characteristics were similar in the three group& Prescriptions to 21 291 out-patients were studied. Fiftysix per cent of the patients were female and 33.8% of all were below 13 years. A mean of 2.7 drugs were prescribed per patient. Commonly used single items as percentage patients prescribed were aspirin (38), ehlorpheniramine (21), cough expectorant (21), and vitamin B-Co (14). The study showed that 33.6% of all patients and 45Z of children below 13 were prescribed antibiotics (sulphonamides included. The antibiotic prescribing decreased from 32.5% to 24.8% (p
PATIENTS, DOCTORS AND THEIR DRUGS - A STUDY AT FOUR INSTITUTIONS IN SRI LANKA G. Tomson, I. Angunawela Drug utilization studies are much needed in developing countries. Our objectives were to elicit information about the patients, pattern of drug use prior to admission and at the wards and the doctors" perceptions of their prescribing. We studied medical wards at Four governmental institutions representing different levels of health care. A random sample of 850 in-patients were interviewed daily at the wards by research assistants. Personal characteristics, drug ingestion 48 Era before admission and at the wards were recorded. Reliability tests were performed on 7% of the sample. All 26 doctors were later interviewed in rela~ tion to their prescribing. Eighty per cent of the patients were rural, mean age 59.3 years, 77.3% had taken Western drugs prior to admission, mean number 3, aspirin and paracetamo] most commonly named. Malaria was the most common diagnosis. The average number of drugs prescribed per patient varied between 2.7 at the University and 5.1 at the Peripheral unit with shorter duration of stay. The most commonly prescribed drugs among all patients as percentage of patients exposed were para~ cetamol (31.3), aspirin (20.9), diazepam (19.5), ehloroquine (14.5), ampicillin and vitamins (both 12.6). Prescribers in the periphery had little access to unbiased drug information and doctors at all levels perceived that they prescribed less than the actual mean number of drugs prescribed per patient. Placebos were perceived to be used by all but two doctors and perceived mean number of patients prescribed placebos varied between the institutions from 20 to 55%. Drug ingestion before admission was common, more drugs were prescribed in the periphery and more information was requested. A Drug Information Bulletin has been initiated. Department of International Health Care Research, (IHCAR), Karolinska Instituter, Box 60400, S-I04 01 Stockholm, Sweden

OP 38.05

OP 39.01

A METHOD TO EVALUAIE EFFECT OF DRUG INFORMAIION, RANDOMIZATION IN GROUPS: AN EXPERIENCE FROM SRI LANKA. V..Diwan, I. Angunawela, G. Tomson

8-ADRENOCEPTOR REGULATION AND CATECHOLAMINE LEVELS IN INSULIN DEPENDENT DIABETES MELLITUS (IDDM) G. Sager, L. Slordal and J. Florholmen Repeated hypoglycaemias with release of catecholamines, may affect the distribution and coupling of ~-adrenoceptots. This can, partly, explain the well-known change in sensitivity to cetecholaminesin IDDM. The present study was undertaken to study the regulation of ~-adrenoceptors of intact mononuclear leukocytes from 8 adults with IDDM in a non-fasting state. The plasma catecholamine levels, determined by HPLC, were similar, except for epinephrine with higher concentrations in IDDM. The 8-adrenoceptors were characterized by ~H-(-)-CGP 12177 in an ultrafiltration assay. The binding affinities (Kd: 200-300 pM) or densities (approximately 1300 sites/cells) were not different between healthy and IDDM-subjects. When the receptor numbers were related to the epinephrine levels, the correlation became negative in controls (r= -0.822), but positive (r= 0.883) in the diabetics. After exposure to isoprenaline, 65~ of the receptors became internalized in both groups. No difference in basal or isoprenalineinduced increase of cAMP accumulation was observed (p >0.05). In the healthy subjects a positive correlation existed between maximal isoprenaline response and receptor density (r= 0.985), whereas no relation was found in the IDDM subjects. The present results show that different levels of the 8-adrenergic signal system is affected in non-fasting IDDM subjects: I) An increase of epinephrine concentrations, 2) A positive relationship between ~-adrenoceptor density and epinephrine levels, 3) No correlation between receptor-density and isoprenaline-induced cAMP response. Dept. of Pharmacology, Institute of Medical Biology, University of Tromso, P.O.Box 977, N-9001 Tromsm, Norway.

Drug information to prescribers should be scientifically evaluated similar to drugs and vaccines~ as only effective and essential information can be afforded especially by developing countries. Due to ethical and practical reasons classical randomized trials (randomization of individual prescribers) can not be used. To overcome these problems randomization of prescribers in groups can be employed. This method is better for several reasons: I. the influence of information on prescribing is evaluated in a natural environment, 2. the power of information disseminated is increased via diffusion, 3. the efficacy Of information is more generalizable, 4. the ethical difficulties avoided, 5. the costs reduced, and 6. the contamination of controls minimized. However the differences in prescribing between the doctors in the group may increase the variance and due to lesser number of units idiosyncratic changes in eontroi or intervention group may be indistinguishable from the effect of information. Group randomization was employed to evaluate the effect of drug information on antibiotic prescribing in primary health care in Sri tanka. Fifteen similar peripheral health units were randomly allocated into two intervention grQups, written and written + verbal information and one contro] group. Prescriptions to over 20 000 outpatients were studied. The experience from this study suggests that information can be evaluated • the natural environment overcoming ethical problems and minimizing contamination. However, the cost savings and increased power via diffusion could not be ascertained. We also need to assess the dose of information and time period necessary to see the effect of this. The problems encountered and efforts to solve them are discussed as well as the applicability of this method in other settings. IRE&R, Karolin~ka Institutet, Uox6O400, 5-10401

Stockholm, S~den

A 104

OP 39.02

OP 39.04

#p-ADRENERGIC TOCOLYTICTHERAPYDECREASESMATERNAL, BUT NOT NEONATALLYMPHOCYTE~2-ADRENOCEPTORDENSITY. ,~ O.-E. Brodde, M.C. Michel, M. Michel-Reher and M. Nohlen " Circulating lymphocytes containing a homogeneouspopulation of ~-adrenoceptors (AR) are a frequently used model to investlgate changes in ~-AR function in humans. We have used this model to study th~ effects of a ~-AR tocolytic therapy on maternal and neonatal ~-AR function. For this purpose we determined simultaneou~ly ~ e r n a l and neonatal lymphocyte #o-AR density (by (-)-[ I]iodocyanopindolol (ICYP) bindiflg) and -responsiveness (10 pM isoprenalineinduced increase in ]ymphocyte cyclic AMP content) in 17 pregnant womenundergoing ~o-AR tocolytic therapy (continuous infusion of 0.32 ~g/mih hexoprenaline plus 3x50 mg/d metoprolol orally for at least 5 days) to prevent preterm labor and in 19 not-treated pregnant womenat term. Mean maternal lymphocyte %-AR density was in not-treated women significantly higher than in hexoprenaline-treated women (1640• vs. 665• ICYP binding sites/cell, p
TRANSDERMAL DELIVERY OF PROPRANOLOLANO MEPINDOLOL: PROFILING IN NORMAL SUBJECTS. C. de Mey, D. Enterling and M. Ederhof. The e f f e c t s of acute and chronic (7 days, od) application of 20 mg/]O sqcm mepindolol (M) and 40 mg/lO sqcm propranolol (P) on investigatienal TSD-patches, were p r o f i l e d vs a matched placebo-patch (R), in double-blind fashion, and period-balanced within-subject cross-over, in 9 normal male volunteers. On the f i r s t and l a s t day of each treatment course the following were assessed: heart rate (HR) and pressure (SBP/DBP) responses to 5 min i v infusion of ] mcg/min isoprenaline (ISO), p r i o r to dosing, and at 4 and 8 hrs a f t e r dosing, to 3 min IHG (Isometric Handgrip: 30% of maximum strength) at 5 hrs, and to 5 min delayed auditory feedback (DAF) at 6 hrs a f t e r dosing. The R-patch was well t o l e r a t e d ; the M-patch was in general well t o le ra t e d , mild i r r i t a t i o n was seen occasionally. The P-patch was not well tolerated and caused i r r i t a t i o n and itching in most subjects; confluent vesicular lesions were seen in 3/9 subjects. On the I s t day of application, mild blunting of the HR & BP responses to [SO at 4 and 8 hrs, and DAF at 6 hrs, was seen with M and P (and s l i g h t l y more so f o r M than P). L i t t l e e f f e c t was seen on the responses to IHG, no changes were seen f o r the supine resting readings. A f t e r I wk od application of the M-patch, ISO responses were almost abolished~, as well p r i o r to dosing ( i . e . 24 hrs a f t e r the previous patch), as at 4 and 8 hrs a f t e r dosing. Responses to OAF and [HG were reduced also, but not to the same extent as f o r the ISO-tests. A f t e r i wk od application of the P-patch, responses to ISO, IHG and OAF were mildly blunted (but f a r less so than with the M-patch). I t is concluded that the transdermal delivery of mepindolol (M) was well tolerated and caused pharmacodynamic equivalents of mild beta-blockade on acute application, and stable, prolonged and pronounced blockade within 1 week once daily application. Propranolol (P) was not well t o le ra t e d , and the equivalents of beta-blockade were f a r less pronounced. SK&F-Institute Appl. Clin. Pharmacol., SKD, G~ttingen, FRG

OP 39.03

OP 39.05

THE EFFECT OF BETA BLOCKERS ON HEART RATE DURING REM AND NON REM SLEEP J.B. Kostis. R.C. Rosen. L.G. Seltzer. L. Taska and B~ Holzer The effect of beta blockers (BB) on the heart rate (HR), at rest, exercise and during the day and night hours has been studled extensively. However, there are no data on the effect of BB on HR during the various sleep atagea.

INVESTIGATION OF CATEC HOLAMINE EFFECTS iN INTACT MAN USING MICRODIALYSIS Peter Arner, Eva Kriegholm, Peter Enafeldt Catecho[amine-induced lipolysis was investigated in situ using microdialysis of the extracellular space of human adipose tissue. A microdialysis probe [Carnegie Medicine) was inserted in the subcutaneous tissue and dialyzed using precision pumps. Various adrenergic agents were added to the ingoing dialysate and glycerol (lipolysis index) was analyzed in the outgoing solvent using an ultrasensitive bioluminescent assay, lsoprenaline (pure beta-agonist) and noradrenaline (combined alpha- and beta-agonist) in doses ranging from 10-12 to 10-5mol/I caused a dose-dependent stimulation of lipolysis in situ without causing general effects, Isoprenaline was always more potent than noradrenaline. There were, however, large individual variations in catecholamine sensitivity. The lipolytic effect of catecholamines was transient but the latter could be completely provented by the addition of glucose to the dialysate. Propranolol [non-se!ective beta-antagonist) inhibited lipolysis and phentolamine inch-selective alphaantagonist] enhanced noradrenaline-induced lipolysis, it is concluded that microdialysis can be used for the investigation of in vivo catecholamine action in intact man. With this technique adipose tissue can be exposed to very high catecholamine doses without causing general effects. In addition, the lipolytic effect of catecholamines is glucose dependent and is the net result of stimulation through beta-receptors and inhibition through alpha-receptors.

We performed polyaomnography and exercise testing in a randomized, double-blind, placebo (PL) controlled, Latin square study of 4 BB with different ancillary properties on 30 healthy men aged 23 to 40 years. The agents used were ateno2ol (A), a beta-1 selective hydrophilic BE; metoprolol (M), a beta-1 selective lipophilie BE; pindolol (PN), a nonselective lipophilic BB with partial agoniat activity (ISA); propranolol, a lipophilio nonselective BB without ISA and placebo. At res%, PN increased RR (P<0.05) while other BB decreased HE (P
A 105

OP 39.06

OP 40.02

TOTAL-BODY CLI~ARANCE AND FRACTIONAL EXTRACTION OF, AND PLASMA CATECHOLAMINE RESPONSI~S TO, ISOPRENALIN~ (ISO)

P R E S S O R A M I N E TESTS (PAT) AND P L A T E L E T A L P H A 2_ R E C E P T O R B I N D I N G (PRB) FOR A S S E S S M E N T OF S T E R E O S E L E C T I V E E F F E C T S OF 0 X A P R O T I L I N E (0XA) E N A N T I O M E R S IN H U M A N S I. W. R e i m a n n , C. B r l t z e l m e i e r , L. F i r k u s n y , H. K e m m l e r , J. M e n a r d , and P. R. B i e c k B o t h o p t i c a l s t e r e o i s o m e r s of OXA, the r a c e m i o ( O H ) - d e r i v a t i v e of m a p r o t i l i n e , are a n t i d e p r e s sants. Only the S ( + ) e n a n t i o m e r (CGP 12 104) inhibits n o r a d r e n a l i n e ( N A ) - u p t a k e . The R ( - ) e n a n t i o m e r (CGP 12 103, l e v o p r o t i l i n e ) may be free of PAT effects. O b j e c t i v e of the study in 6 vol u n t e e r s : e v a l u a t i o n of the p r e d i c t i v e v a l u e of PAT u s i n g NA and t y r a m i n e (TYH), and of PRB as i n d i c a t o r s for N A - u p t a k e i n h i h i t i o n . P l a c e b o (P), CGP 12 104 (25 mg bid) or CGF 12 103 (50 mg bid) w e r e g i v e n for 9 d. On d i0, tests w e r e done: PRB b e f o r e , and PAT I h a f t e r the last dose. PAT: I n t r a v e n o u s NA lug/min] or TYR Img] doses w h i c h i n c r e a s e syst. BP by > 30 mm Hg. PRB: B [ a l p h a o - a d r e n o c e p t o r b i n d i n g sites/ platelm~, K D ~n~l, means + SD. Results : P C G P 12 103 C G P 12 104 NA 9.5 + 2.2 11.5 + 3.1 2.2 + 0.8 TYR 4.0 +- 1.2 4.3 ~ 1.5 18.4 ~_ 7.4 B 331 + 59 310 + 80 330 + 88 max K_ 2.1 + 0.60 2.3 + 0.14 2.7 + 1.54 T~e N A - u p t a k e i n h i b i t i n g p r o p e r t y of COP 12 104 is m i r r o r e d in the 5 - f o l d c h a n g e of p r e s s o r sens i t i v i t y to NA and TYR. COP 12 103 had no effect. N e i t h e r i n f l u e n c e d a l p h a 2 - r e c e p t o r density or a f f i n i t y of p l a t e l e t s . Summary: C o n t r a r y to CGP 12 104, l e v o p r o t i l i n e does not i n f l u e n c e p r e s s o r a m i n e e f f e c t s . W h i l e PAT are s e n s i t i v e , PRB c a n n o t be u s e d as predictor of N A - u p t a k e i n h i b i t i n g a c t i v i t y of COP 12 104 in humans. Humanpharmacology I n s t i t u t e , C I B A - G E I G Y GmbH, WaldhSrnlestr. 22, D - 7 4 0 0 T S h i n g e n , FRG

J. Ludwig, T. HalbrLigge, J, W a l t e r a n d K . - H , G r a e f e T w o c o n s e c u t i v e , 2 5 - m i n i n t r a v e n o u s i n f u s i o n s o f ISO (involving c o n s t a n t r a t e s o f 3 1 - 4 3 a n d 8 0 - i 2 4 pmol k g -1 min -1, r e s p e c tively) w e r e given to 7 h e a l t h y s u b j e c t s . Five o f the 7 s u b j e c t s w e r e s t u d i e d a g a i n a f t e r p r e t r e a t m e n t w i t h d e s i p r a m i n (DMI, 1.S m g k g -1 p.o. 3 h p r i o r t o t e s t i n g ) , to b l o c k n e u r o n a l u p t a k e . The t o t a l - b o d y (ERt), p u l m o n a r y (ERp) as well as f o r e a r m (ERf) f r a c t i o n a l e x t r a c t i o n a n d the t o t a l - b o d y c l e a r a n c e (CI t) o f ISO w e r e o b t a i n e d f r o m m e a s u r e m e n t s , o f c a r d i a c o u t p u t (CO: t h e r m o d i l u t i o n ) a n d t h e s t e a d y - s t a t e ISO c o n c e n t r a t i o n in mixed central-venous, arterial and forearm venous plasma. C o n c e n t r a t i o n - d e p e n d e n t l S O - i n d u c e d i n c r e a s e s in C O r e s u l t e d in increases in Cl t ( a m o u n t i n g to 21Z o f t h e i n c r e a s e in C O o f p l a s m a ) , d e c r e a s e s in ERt a n d no c o n s i s t e n t c h a n g e in ERr. ERp did n o t d i f f e r f r o m zero. ISO a l s o p r o d u c e d c o n c e n t r a t i o n d e p e n d e n t i n c r e a s e s in t h e c e n t r a l venous p l a s m a level o f n o r a d r e n a l i n e (NA) a n d d e c r e a s e s in t h a t of a d r e n a l i n e (A). Inhibition o f n e u r o n a l u p t a k e by DMI did n o t a l t e r any of the p h a r m a n o k i n e t i c p a r a m e t e r s of ISO. On t h e o t h e r hand, DMI r e d u c e d t h e c e n t r a l v e n o u s b a s e l i n e p l a s m a level of NA (47%) and t e n d e d to r e d u c e t h a t of A (34%). Moreover, it e n h a n c e d (by a f a c t o r o f 2.4) the p l a s m a NA r e s p o n s e a n d did n o t a f f e c t the p l a s m a A r e s p o n s e to ISO. Hence, ISO m o d u l a t e s its o w n p h a r m a c o k i n e t i c s , which involve n o n - n e u r o n a l r e m o v a l p r o c e s s e s only. The fall in p l a s m a A c o n s e q u e n t to ISO i n f u s i o n i n d i c a t e s t h a t the p l a s m a c l e a r a n c e of A is likewise C O - d e p e n d e n t . DMI a p p e a r s t o r e d u c e s y m p a t h e t i c activity. The D M I - i n d u c e d , 2 . 4 - f o l d e n h a n c e m e n t o f t h e p l a s m a NA r e s p o n s e t o 1$O p o i n t s t o w a r d s n e u r o n a l u p t a k e r e c a p t u r i n g a t l e a s t 58Z of t h e s y n a p t i c NA r e l e a s e d in r e s p o n s e to ISO. ( S u p p o r t e d by t h e DFG a n d t h e Bayer AG) M e d i z i n i s c h e Poliklinik und l n s t i t u t f u r P h a r m a k o l o g i e d e r H n i versit~it WUrzburg, D - 8 7 0 0 W i i r z b u r g , FRG

OP 40.01

OP 40.03

DETERMINATION AND COMPARISON OF THE PRESSOR EFFECT OF TYRAMINE (ADMINISTERED IN TYRAMINE RICH MEAL) DURING CHRONIC MOCLOBEMIDE AND TRANYLCYPROMINE TREATMENTS IN HEALTHY SUBJECTS. l.Berlin, A. Cournot, AM. Pedarriosse, R. Zimmef and A.J. Puech. Dept. of Clinical Pharmacology, Hop. de la SalpStri~re,47,Bd de l'Hopital, 75013 Paris, Therapharm Reeherches, 19, rue de la Tour, 75016 Paris, Produits Roche, 52,Bd du Pare, 92521 Neuilly/Seine, Hoffmann-La Roche Ltd. Ch-4O02 Basle. The risk of interaction with tyramine (cheese effect) limits utilization o f monoamine oxidase inhibitors (MAOI). Moclobemide (M) is a new reversible MAOI with clear antidepressant properties. In this double blind, randomized, parallel groups study its potentiation of tyramine pressor effect was compared to that of tranylcypromine (T) in 16 healthy volunteers. Oral tyramine sensitivity was determined in fasting condition and after meal during a placebo run-in period and after 2 weeks of M (200 mg t.i.d.) or T (i0 mg b.i.d.) administration. Tyramine sensitivity was evaluated after increasing doses of tyramine given after meal and mixed with tyramine free yoghurt. The dose of tyramine was increased each day until systolic blood pressure (SBP) rose > 30 mmHg which was considered as the tyramine threshold dose (Tyr 30).Fasting oral Tyr 30 (without medication) was 2.8fold lower than after meal. Tyr 30 decreased from 1450 (381) mg (• on placebo to 306 (105) mg on M (factor 5) and from 1200 (213) mg on placebo to 35 (12) mg (factor 38) on T. Thus, the rise in tyramine sensitivity was 7.6fold greater during T than M administration. Treatments did not alter the rise in SBP or DBP after Tyr 30. Tyramine dose-response curves showed no correlation between the dose of tyramine and SBP increase. Duration of SBP increase lasted longer with T (126 • min) than with M (69• min, P<0.01). From a practical point of view, all subjects taking T increased their SBP > 30 mmHg with a Tyr 30 less than 50 mg, dose which may he ingested in a normal meal whereas even the most sensitive subjects taking M has a Tyr 30 greater than 150 mg which seems to be incompatible with a normal meal.

CONTROLLED-RELEASE LEVODOPA/CARBIDOPA (CR-4) IN PARKINSONIAN PATIENTS WITH SEVERE RESPONSE FLUCTUATIONS: CLINICAL AND PHARMACOKINETIC DATA D. Deleu, M. J a c q u e s , Y. M i o h o t t e a n d G. E b i n g e r P h a r m a o o k i n e t i e d a t a a n d c l i n i c a l e f f i c a c y of a novel s u s t a i n e d - r e l e a s e p r e p a r a t i o n of l e v o d o p a / c a r b i d o p a (LD/C) C R - 4 (200/50) w e r e c o m p a r e d to that of p r e v i o u s s t a n d a r d (Std) L D / C (250/25) t r e a t m e n t in 17 p a t i e n t s w i t h i d i o p a t h i c P a r k i n son's disease and severe response fluctuations in o p e n trial. The a v e r a g e d u r a t i o n of the disease was 8.2 y e a r s a n d a v e r a g e age w a s 60~. F o u r p a t i e n t s w i t h d r e w f r o m the study, 2 due to lack of t h e r a p e u t i 9 e f f i c a c y . In all C R - 4 treated p a t i e n t s there w a s a s i g n i f i c a n t i n c r e a s e in "on" time ( 6 7 . 5 % ( S t d ) vs 8 2 , 5 % ( C R - 4 ) ) , r e d u c t i o n in n u m b e r s of "off" p e r i o d s (3.7 vs 1.6) a n d red u c t i o n of d i s a b i l i t y (13.8 vs 8.4). The m e a n int e r d o s e i n t e r v a l i n c r e a s e d w i t h 2 7 % and the n u m b e r of d a i l y d o s e s w a s r e d u c e d w i t h 15%. The optimal dose r e q u i r e m e n t a d m i n i s t e r e d as C R - 4 w a s not s i g n i f i c a n t l y d i f f e r e n t f r o m Std LD/C. F o r c o m p a r i s o n of the 2 f o r m u l a t i o n s , 6 m o s t s e v e r e l y a f f e c t e d p a t i e n t s w e r e s u b j e c t e d to a i O - h o u r dur i n g L D - d r u g m o n i t o r i n g . M e a n P l a s m a LD c o n c e n t r a t i o n s did n o t d i f f e r s i g n i f i c a n t l y . H o w e v e r , the b i o a v a i l a b i l i t y ( A U C / m g LD) w a s h i g h e r d u r i n g C R - 4 t r e a t m e n t (0.0075 vs O . O 1 7 ) ( p ~ O . 0 5 ) ; Tmax i n c r e a s e d f r o m 0.6 to 1.8 (p,O.O01). We c o n c l u d e that C R - 4 p r o d u c e s s i g n i f i c a n t c l i n i c a l i m p r o v e m e n t o v e r Std L D / C in P a r k i n s o n i a n p a t i e n t s w i t h s e v e r e m o t o r f l u c t u a t i o n s . The l a c k of p r e d i c t a b i l i t y of o n s e t of c l i n i c a l r e s p o n s e m a y r e m a i n the m a j o r d r a w b a c k for t r e a t i n g r e s p o n s e f l u c t u a tots w i t h C R - 4 alone. Dept. of N e u r o l o g y , U n i v e r s i t y H o s p i t a l and P h a r maceutical Institute, Vrije Universiteit Brussel, L a a r b e e k l a a n 101-103, B - I O 9 0 B r u s s e l s , B e l g i u m .

A 106

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OP 40.06

CLINICAL EFFECTS OF MIANSERINAND PLASMALEVELS OF MIANSERINAND DESMETHYLMIANSERIN K.Otani,H.Sasa,T.Kondo,T.Hirano,S.Kaneko,Y.Fukushima,H.Higuchi We studied the relationship between the c l i n i c a l e f f e c t s of mianserin(M) and plasma levels of M and desmethylmianserin(D),an active metabolite of M, to c l a r i f y whether the monitoring of these compounds' levels improves M treatment. Methods: The subjects consisted of 23 depressed patients(13 male and I0 female,mean age•177 who consented to be involved in this study. M was prescribed at bed time for 3 weeks.The dose was 3O,g in 21 cases,and 2010 in 2. Depressive symptoms and side effects were rated weekly by Montgomery - Asberg scale(MAS) and UKU soale(ll items), respectively. The patient with a final MAS score of < I 0 was defined as a responder,ll-I9 as a partial-, and ~20 as a non-responder. Plasma levels of ~ and D were measured by a HPLC method. Wilcoxon rank-sum test was used for the statistial analyses. Results: Out of 13 cases where antidepressant e f f e c t s could be studied(major depression,MAS score before treatment ~ 2 0 ) , 6 were r e s p o n d e r s , 2 p a r t i a l - , a n d 5 were non-responders. The N+D levels of the responders were between 87 and 176 nM. Only 3 non- or partial-responders were within this range, while the others were below or above this range. Amelioration scores were also high in this range. Out of 23 cases, 14 cases(61%) exhibited some side effects. Dry mouth and constipation were the most couch side e f f e c t s (5 cases,22%). Two cases showed hepatic injuries. There was no s i g n i f i c a n t relationship between the occurrence of the side e f f e c t s and plasma levels of M or D. Conclusion: Our results suggest a therapeutic window of N+D levels. The side e f f e c t s caused by ~ do not seem to be dependent on M or 0 levels. Dept. of Neuropsychiatry, Hirosaki University Hospital, Hirosaki 036, Japan

ALERTNESS AND PERFORMANCE IN MAN WITH ENANTIOMERS OF CHLORPNENIRAMINE AND DIMETHINDENE PA Pascoe, AN Nicholson, C Turner, CR Ganellin, AF Casy, AD Mercer Antihistamines may lead to drowsiness and impaired performance, but they are unlikely to be specific HI antagonists. In this context, we have examined the effects of the enantiomers of chlorpheniramine and dimethindene. Their affinities for HI receptors are highly stereoselective, and so studies with these drugs may help to establish whether sedation can be due to Hl antagonism alone. Compounds were resolved into their enantiomers by fractional crystallisation, and their meleates encapsulated with lactose. 6 healthy volunteers (19-28 years) each ingested on separate occasions 10mg of (+) end (-)chlorpheniramine, 5mg of (+) and (-)dimethindene, 5mg of triprolidine (active control), and two placebos. Sleep latencies, subjective sleepiness and digit symbol substitution were measured 1.0h (0830h) before and 0.5, 1.5 and 3.0h (I000, ii00 and 1230h) after ingestion. Differences between changes in measures from before (0830h) to after ingestion were analysed. No differences could be established at 1000h. At ll00h reductions in sleep lateneies were greater with (+)chlorpheniramine and with (-)dimethindene than with their respective enantiomers and with placebo (p < 0.05). Increased subjective sleepiness was greater at ii00 and 1230h with (+)chlorpheniramine than with the (-)isomer (p <0.01) and with placebo (p < 0.05), and at 1230h with (-)dimethindene compared with the (+)isomer (p < 0.05). Impairment of performance was greater at Ii00 and1230h with (+)chlorpheniramine than with the (-)isomer (p <0.05). As only (+)chlorpheniramine and (-)dimethindene, the active enantiomers, lead to drowsiness and impaired performance, it is concluded that sedation can arise from HI antagonism alone. Royal Air Force Institute of Aviation Medicine, Farnborough, Hampshire, United Kingdom

OP 40.05

OP 41.01

PHARMACOKINETICS OF CLOMIPRAMINE. EFFECTS OF VARYING DOSAGES AND ROUTES OF ADMINISTRATION J.M. Perel, B.G. Pollock and R.S. Nathan We have been studying the effects of Clomipramine (CMI) under pulse-loading conditions(N=30) and as a seretonergic probe(N=lO) in depressed patients and normal subjects. Acute dosages ranged from 12.5 mg i.v, to 200 mg i.v. or 200 mg po. Timed plasma samples were collected for periods of up to 120 hrs after drug administration,analyses being done with a new High-Performance-Liquid-ChromatographicMethod with electrochemical detection,limit of detection: 0.5 ng/ml and Coefficient of Variation: 8.4% at 1 ng/ml to 4.3% at i00 ng/ml. Mean elimination half-lives for CMI were 18 hrs at low dosages to 38 hrs at 200 mg.The plasma levels of the noradrenergic N-desmethyl metabolite (DCMI) were much lower than the parent under i.v. and much greater after po. - the ratio eventually reading 3.7 with a disproportionate increase of the AUCs at higher dosages. Considerable concentrations of the serotcnergic 8-hydroxy metabolite of CMI were also found,which often were greater than DCMI. The relative neurochemical contributions by these compounds were assessed by neuretransmitter uptake measurements wi~h rat hypothalamic synaptosomal preparations plus the timed plasma samples. During the plasma level decay phases,even at lower drug concentrations,the potencies of the corresponding neurochemieal effects were retained. Pharmacokinetics were best fitted with either two - or three-compartment modeling. We conclude that CMI and DCMI both undergo dose-dependent kinetics of elimination leading to concurrent differences in clinical neuropharmacological profiles.

CLINICAL SIGNIFICANCE OF AMBULATORY BLOOD PRESSURE MONITORING A. Itabashi, S. K a t a y a m a , Y. M a r u n o , M. Inaba, a n d J u n Ishii. B l o o d p r e s s u r e ( B P ) m e a s u r e d by the d o c t o r in the office and a m b u l a t o r y BP r e c o r d e d every hour t h r o u g h o u t 24 h o u r s w i t h a n o n i n v a s i v e a u t o m a t e d BP m o n i t o r i n g d e v i c e w e r e c o m p a r e d in 10 normot e n s i v e s a n d 162 h y p e r t e n s i v e s . C a s u a l BPs significantly correlated with averages of ambulatory BPs t h r o u g h o u t the 24 hours, during day (7am-10pm) a n d d u r i n g n i g h t (0-5am). 6 out of 10 normotensives and all of m o d e r a t e to severe hypertensives had a m b u l a t o r y BPs of m o r e than 1 5 0 / 9 0 m m H g at least o n c e d u r i n g 2 4 - h o u r period. The i n c i d e n c e of a m b u l a t o r y B P s h i g h e r t h a n 150/ 90mmHg was g r e a t e r in untreated and treated h y p e r t e n s i v e s w i t h d i a s t o l i c BP of m o r e t h a n 105 m m H g in the office. On the o t h e r hand, o n e - t h i r d to o n e - f i f t h of t r e a t e d h y p e r t e n s i v e s w i t h d i a s tolic o f f i c e BPs less t h a n 1 0 5 m m H g had a m b u l a t o ry BPs less t h a n 1 5 0 / 9 0 m m H g throughout 24hrs. When e f f e c t of n i c a r d i p i n e (60 mg, t.i.d.) or slow-release nifedipine (27.3• mg, b . i . d . ) on m i n i m u m BP d u r i n g the n i g h t w a s c o m p a r e d , longacting nifedipine d e c r e a s e d BP t h r o u g h o u t the n i g h t to l e v e l s n o t s i g n i f i c a n t l y d i f f e r e n t f r o m normotensive controls, w h e r e a s s h o r t - a c t i n g nic a r d i p i n e d i d n o t lower BPs in the night. Slowr e l e a s e n i f e d i p i n e (20 mg, b.i.d.) demonstrated a p r o f o u n d fall in BP a m o u n t i n g 7 7 / 4 9 m m H g d u r i n g the n i g h t in s o m e of the p a t i e n t s . T h e s e r e s u l t s suggest a simple ambulatory BP monitoring throughout the d a y g i v e s us u s e f u l information to evaluate the e f f i c a c y of antihypertensive medication as w e l l as to avoid overtreatment resulting in a g r e a t fall in BP during sleep w i t h l o n g - a c t i n g h y p o t e n s i v e agents. D e p a r t m e n t of M e d i c i n e , S a i t a m a M e d i c a l School, M o r o y a m a c h o , I r u m a g u n , S a i t a m a , 350-04, Japan.

Clinical Pharmacology Program, Western Psychiatric Institute and Clinic, Univ, of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA.

A 107

OP 41.04

OP 41.02 A C T I V A T I O N OF N E U R O H U M O R A L IN C H R O N I C H E A R T F A I L U R E

SYSTEMS AND PROGNOSIS

B.Stanek,C.Punzengruber,M.Klizpera K.Silberbauer

and

The a c t i v i t y of v a s o p r e s s o r and d i l a t o r s y s t e m s w a s a s s e s s e d at s u p i n e r e s t in 43 p a t i e n t s ( 3 4 m e n , 9 w o m e n , m e a n age 6 0 ~ 2 y e a r s ) w i t h m o d e r a t e to severe chronic heart failure.During follow-up l a s t i n g 1 to 60 m o n t h s 32 p a t i e n t s d i e d ( a l l b u t one N Y H A I I I - I V , m e a n s u r v i v a l 9,2+2 m o n t h s and 7 out of 17 p a t i e n t s N Y H A I I , m e a n s ~ r v i v a l 21,9!6 months).In patients,who died,plasma norepin e p h r i n e ( 7 2 3 ~ 8 9 vs 3 1 4 ~ 5 2 p g / m l p < 0 , 0 0 1 ) , e p i n e p h r i n e ( 1 2 2 J 1 3 vs 5 6 J 7 p g / m l p ~ 0 , 0 0 1 ) , r e n i n a c t i v i t y ( 3 , 1 ~ 0 , 6 vs 1 , 0 ! 0 , 2 n g / m l / h p < 0 , 0 5 ) , a n g i o t e n s i n I I ( 3 3 J 4 vs 2 1 ~ 5 p g / m l < p 0 , 0 5 ) , a l d o = s t e r o n e ( 3 8 3 ~ 9 9 vs 1 4 7 ~ 3 1 p g / m l p < 0 , 0 2 5 ) a n d b i = c y c l o - p r o s t a g l a n d i n E ~ - m e t a b o l i t e ( 6 8 + 7 vs 49+3 p g / m l p<0,025) w e r e h i g h e r t h a n in s ~ r v i v o r s ? In p a t i e n t s N Y H A I I as a s u b g r o u p , h o w e v e r , o n l y p l a s m a n o r e p i n e p h r i n e ( 8 4 4 ~ 2 0 9 vs 2 7 4 ~ 3 7 p g / m l p<0,025) and e p i n e p h r i n e ( 1 2 3 ~ 3 2 vs 5 0 , 2 ! 4 p g / m l p<0,05) w e r e e l e v a t e d in p a t i e n t s , w h o d i e d f r o m p r o g r e s s i v e h e a r t failure, w h i l e t h e a c t i v i t y of the r e n i n s y s t e m was s i m i l a r in b o t h groups. T h e s e d a t a s u g g e s t t h a t the s y m p a t h e t i c n e r v o u s system might play a preferential role among n e u r o h u m o r a l s y s t e m s as a g u i d e to p r o g n o s i s in m i l d h e a r t failure. II.Medizinische Universit~tsklinik Wien G a r n i s o n g a s s e 13 A - 1 0 9 0 W i e n 0 s t e r r e i c h

THROMBOXANE SYNTHASE INHIBITION MODULATES AN EXERCISEINDUCED CHANGE IN PROSTAGLANDIN AND CATECHOLAMINE LEVELS A. Ohniahil,~ K. Yasuda I, T. Fujita I, T. Ishizaki3andT. Tanak~ To study the effect of a new thromboxane (Tx) synthase inhibitor, DP 1904, on the generation of prostaglandins (PGs) and catecholamines (CAs) following a short-term (3-min) exercise, 9 healthy male subjects received the oral daily dose of 800 mg (400 mg, b.i.d.) of DPI904 for 7 days and undertook treadmil excercise (Bruce protocol) before and on 6th day of the treatment period. Serum and urine PG metabolites and urine CAs were monitored before, on 4th day and after the treatment. In addition, serum and plasma PG metabolites and plasma CAs prior to, immediately after and 30 min after the exercise were measured before and on the 6th day after the repeated dosings. The drug caused a decrease in serum TxB2 levels and daily urinary excretions of TxB2 and ll-dehydroTxB2, while an increase in serum 6-keto-PGF1~ levels. Pretreatment serum and plasma TxB2 and ll-dehydroTxB2 increased significantly (p < 0.05) for 30 min postexercise compared with the preexercise values. On theposttreatment 6th day these increments were not observed and the pre- and postexercise PG metabolites were significantly (p < 0.01) lower than the respective pretreatment values. Plasma CA concentrations increased significantly (p < 0.05) immediately after and returned by 30 min after the exercise to the preexercise baseline values in the pre- and posttreatment 6th day study phases. Plasma norepinephrine and epinephrine levels did not change by the treatment, whereas the posttreatment exercise-induced plasma dopamine level was significantly (p < 0.01) lower than the pretreatment value. The results suggest that a new thromboxane synthase inhibitor, DP1904, suppresses the increment of Tx production and modulates CA disposal induced by an exercise. ITokyo Pharmacological Research Center, 2Department of Medicine (I), Daisan Hospital, the Jikei University School of Medicine, and 3Division of Clinical Pharmacology, Clinical Research Institute, National Medical Center, Tokyo, Japan

OP 41.03

OP 41.05

DOPAMINE DOES NOT MEDIATE THE ACTION OF ~-HUMAN ATRIAL NATRIURETIC PEPTIUE IN MAN S.Kageyama, J.Brown, R. Causon, M.O'Flynn, V.R.Aber and C.T.Dollery The role of dopamine synthesis in the renal actions of K-human atrial natriuretic peptide (ANP) was investigated in 6 dehydrated healthy volunteers using the DOPA decarbbxylase inhibitor carbidopa. Each subject received placebo or 50 mg of carbidopa orally 15 hours and 3 hours before an infusion of ANP (10 pmol/kg/min for I hour) in a single blind crossover study. Their responses to placebo alone and to carbidopa alone were also investigated on 2 separate occasions in a similar way. Infusion of ANP produced similar increases of plasma irmnunoreactive ANP whether placebo or carbidopa pretreatment was given. Urinary dopamine excretion was increased by ANP. Carbidopa pretreatment substantially attenuated this increase of urinary dopamine excretion without affecting the natriuretie or water-diuretic response to ANP. Carbidopa also failed to alter the glomeruiar responses to ANP. These r&sults suggest that increased synthesis of intrarenal dopamine is not required for the renal effects of ANP in man. Nevertheless, the results do not exclude a permissive role of residual dopamine formed after carbidopa pretreatment. Departments of Medicine and Clinical Pharmacology, Royal Postgraduate Medical School, Hammersmith Hospital, Du Cane Road, London W12 ONN, United Kingdom

S E R O T O N E R G I C SYSTEM IN H Y P E R T E N S I O N AND DURING ANTIHYPERTENSIVE TREATMENT R. Dzdrik~ K. ~ e b e k o v ~ N. F e f k o v s k ~ I m p a i r m e n t in s e r o t o n e r g i c system plays a role in d e v e l o p m e n t and m a i n t e n a n c e of h y p e r t e n s i o n . A t h e r o g e n i c and m i t o g e n i e a c t i v i t i e s of serotonin (5HT) c o n t r i b u t e to a c c e l e r a t i o n of a t h e r o sclerosis. The aim of m o d e r n a n t i h y p e r t e n s i v e drugs (AHD) is to n o r m a l i z e the blood p r e s s u r e and s i m u l t a n e o u s l y to i n h i b i t / p r o h i b i t the dev e l o p m e n t of a t h e r o s c l e r o s i s . In acute and longterm studies the q u e s t i o n was e l u c i d a t e d whet h e r / h o w d i f f e r e n t AHD i n f l u e n c e 5HT m e t a b o l i s m . P a t i e n t s were t r e a t e d with various AHD in doses e f f e c t i v e l y r e d u c i n g high blood pressure: Under n i t r e n d i p i n e t r e a t m e n t d e c r e a s e in plasma 5HT levels, slight d e c r e a s e in p l a t e l e t aggregation (PA) and no c h a n g e s in 5HT or 5 - h y d r o x y i n d o l a c e t i c acid (5HIAA) u r i n a r y e x c r e t i o n s were observed. During e n a l a p r i l t r e a t m e n t plasma 5HT levels decreased, urinary e x c r e t i o n s of 5HT and 5HIAA showed no changes. U r a p i d i l and ket a n s e r i n d e c r e a s e d PA, i n c r e a s e d renal m e t a b o lism of 5HT but did not i n f l u e n c e 5HT plasma levels. L a b e t a l o l d e c r e a s e d 5HT u r i n a r y e x c r e t i o n but did not i n f l u e n c e 5HIAA excretion. M e t i p a m i de even i n c r e a s e d plasma 5HT levels. It is c o n c l u d e d that AHD with d i f f e r e n t m e c h a nisms of action d i v e r s e l y i n f l u e n c e 5HT m e t a b o lism. AHD d e c r e a s i n g plasma 5HT levels and/or PA appear to be a d v a n t a g e o u s to those w i t h o u t these effects. M e d i c a l Bionics R e s e a r c h Institute, JedZova 6, 833 08 Bratislava, C z e c h o s l o v a k i a

A 108

OP 41.06

OP 42.02

ACUTE CAFFEINE ADMINISTRATION ATTENUA2ES BAEOREFLEX ACTIVITY IN MAN C.J.Tseng,R.Mosgueda-Garcia~l. Bia6~ioni~R.M:Eobertson and D.Robertson Our previous studies have shown that caffeine and other adenosine antagonists attenuate baroreflex activation in anesthetized rats.The purpose of this study was to investigate the possible effects of a single caffeine adminis~ tration on baroreflex activity in man. Normotensive young volunteers were studied after abstain from caffeine for 7 days. Intraarterial blood pressure(BP) and heart rate (HR) were recorded continuously and barnreflex responses were elicited by different doses of phenylephrine (25 to 150 ug/Kg, i.v.). The baroreflex sensitivity was estimated by the slope of the relationship between the increase in systolic BP and the consequent increase in pulse period. Baroreflex responses were obtained at 0,30,60,120 and 180 min after drug (either placebo or 250 mg caffeine p.o.) administration. Basal BP was 127~8/ 57~h ~xHg (n=6), and heart rate (HR) was 65~5 beats/min. The control baroreflex slope was 31• ms/mmHg. At 30 min after caffeine ingestion, BP had risen to 136• m~nBg~ F~ was unchanged, and the slope had decreased to iI.6~2 ms/z~.Hg (D<0.01)-at 120 ~in after caffeine, BP remained elevated (13hZ3 mm~g) and the baroreflex response was 20~5 ms/~Hg. Plasma caffeine concentrations ~ determined by EPLC increased to 1.26~0.h2 ug/ml at 30 min and to 3.1h~0.h7 ug/ml at 120 mi~. There are no significant chanKes in BP, HE and baroreflex slope in four placebo treated subjects. These results suggest thst acute administration of caffeine attenuates baroreflex activity in man. Department of Pharmacology, NaZional Defense Medical Center P.O. Box 900h8-50h, Taipei~ Taiwan~ and Division of Clinical Pharmecology and Cardiology, ~anderbilt University, Nashville, TN.

LACK OF EFFECT OF PROPAF~ONTHE DILTIAZ~

PHARMACOKINETICS

OF

H. Bechtold, E. J~hnchen and D. Trenk It has been suggested that concomitant administration of the class Ic-antiarrhythmic drug propafenone increases the steady-state plasma concentrations of the calcium antagonist diltiazem probably by impairment of the hepatic metabolism of diltiazem by propafenone. Thus, we investigated if the additional treatment with propafenone alters the pharmacokinetics of diltiazem in 8 patients (4 males, 4 females; age 64 • 7 years) with coronary heart disease (4), hypertrophic cardiomyopathy (2), dilative cardiomyopathy (i) or atrial flutter (i), who in addition suffered from ventricular ectopic beats or atrial flutter. We determined the plasma concentrations of diltiazem and propafenone within a dosing interval during therapy with diltiazem alone (3 x 60 mg) and during concomitant treatment with propafenone (3 x 150 mg). The additional administration of propafenone had no effect on the area under the plasma concentration-time curve of diltiazem (481 • 295 ng'hr./ml diltiazem alone; 524 + 180 ng'hr,/ml diltiazem plus propafenone; p=0.476). The same holds true for the corresponding average steadystate plasma concentration of diltiazem within the dosing interval (80.2 • 49.1 vs, 87.3 • 29.9 ng/ml; p=0.477). The average steady-state plasma concentration of propafenone-HCl was 285.8 • 86.4 ng/ml. The combination of diltiazem and propafenone increased statistically significantly the PQ-interval in the ECG at rest from 0.16 • 0.02 (diltiazem alone) to 0.19 • 0.03 s (diltiazem plus propafenone; p<0.002). These results demonstrate that the pharmacokinetics of diltiazem were not affected by concomitant administration of propafenone. A negative dromotropic effect is obvious when this combination is administered. Caritaskrankenhaus, uhlandstraBe, D-6990 Bad Mergentheim and Abteilung fur Klinische Pharmakologie, Rehabilitationszentrum, S~dring 15, D-7812 Bad Krozingen

OP 42.01 ESTIMATION OF POPULATION PHARMACOKINETIC DRUG - DRUG INTERACTION OF MEXILETINE FROM ROUTINE CLINICAL TRIAL DATA. P. BURTIN, P. GIRARD and J.P. BOISSEL Plasma drug concentration (Cp) are often collected during phase III clinical trials, for controlling compliance. These data cannot be analysed by classical pharmacokinetic (Pk) methods, because the number of points by subject is too small, although subjects are numerous, So, we have used a population Pk method, NONMEM (i), to assess the variability of 663 mexiletine Cp at steady state, from 252 post myocardial infarction patients, enrolled in the IMPACT trial (2). The points were fitted to a one compartment model with first order absorption. The influence of age, gender, body weight (BW) and comedications on the parameters of absorption, hepatic and renal clearance were tested with various models. The best model showed that volume of distribution was proportional to BW and that digitalies and nitrates reduced metabolic clearance by about 20%. The significant influence of these covariates was confirmed by multiple linear regression. Such application of population pharmacokinetie on routine clinical trial data offers the opportunity of making serendipity, as a drug - drug interaction, that should be confirmed by further experimental studies. I-SHEINER. ROSENBERG & MARATHE, 1977, J. of Pk. and Biopharm. 5 : 455-478. 2-IMPACT research group, 1984, J. Am. Clin. Cardiol.,4 : 11~8-I163. Unit6 de Pharmacologie Clinique, H6p. Neuro Cardiologique, 162 av. Lacassagne 69424 LYON CEDEX 03, FRANCE

OP 42.03 INCRFASED BETA-ADRENOCEPPOR BLOCKING ACTIVITY OF METO P R O L O L B Y CO~'~)MITANT A D M I N I S T R A T I O N O F D I ~

D. Trenk, F. Wa~ner and E. J~hnchen Concomitant administration of the antiarrhythmic drug propafenone and the beta-adrenoceptor antagonist metoprolol results in a 2- to 5-fold increase in the plasma concentration of metoprolol most likely due to inhibition of the first-pass metabolism of metoprolol by propafenone. The new class Ic-antiarrhythmic compound diprafenone is structurally closely related to propafenone. We therefore investigated if diprafenone also effects the metabolism and the beta-adrenoceptor blocking activity of metoprolol as assessed by reduction in exercise induced tachycardia in 6 healthy volunteers following oral administration of single doses of metoprolol (50 mg), diprafenone (200 mg) or the combination of both drugs. Concurrent administration of diprafenone increased statistically significantly the area under the plasma concentration-time curve of metoprolol from 251 • 67 to 495 • 166 ng'hrs./ml (p<0.01). This corresponds to a reduction in the oral clearance (CL/f) of metoDrolol from 3547 + 1048 to 1828 • 514 ml/min, (p<0.005). The pharmacokinetics of diprafenone were not altered by the additional administration of metoprolol. Metoprolol and diprafenone reduced the tachycardia induced by bicycle ergometry (200 watts) maximally by 16.4 • 5.8 % and 9.6 • 5.3 %, respectively. The latter effect is significantly (p<0.05) amplified to 21.1 • 5.1% if both drugs are ingested together. Analysis of the plasma concentration-effect relationships of diprafenone and metoprolol suggests that this increase in beta-adrenoceptor blocking activity is mainly due to the increased plasma concentrations of metoprolol in the presence of diprafenone and only to a minor part due to the direct beta-adrenoceptor blocking activity of diprafenone itself. Abteilung f~r Klinische Pharmakologie, Rehabilitationszentrum, S~dring 15, D-7812 Bad Krozingen

A 109

OP 42.04

OP 42,06

CALCIUM CHANNEL BLOCKER NIFEDIPINE AND PHOSPHODIESTERASE-INHIBITOR ENOXINONE HEMODYNAMIC AND

DRUG INTERACTIONS WITH THE BILIARY EXCRETION OF DIGOXIN IN MAN A.Hedman. B.Anaelin. A.Arvidsson. R.Dahlovist. B.Nilsson. M.Olsson and K.Schenck-Gustafsson. Digoxin (D) is subjected to kinetic interactions with several drugs, like quinidine (Q) which causes a twofold increase in the steadystate plasma D, due to inhibition of both renal and non-renal elimination. We here report results from investigations ol the influence of Q, quinine (K) -the diastereomer of Qand verapamil (V) on renal and biliary clearance of D. Methods: Steady-state renal and biliary clearance of D were determined before and during maintenance treatment with Q (400600 mg b i d; n=9), K (250 mg t i d; n=8) or V (80 mg t i d; n=6). Biliary clearance of D was measured by a duodenal marker perfusion technique. Plasma, urine and bile were collected hourly during 6-8 hours. Results: Q reduced the renal clearance of D by on average 30% (164_+47 v s 115+23 ml/min) and its biliary clearance by 44% (104_+29 v s 58• rnl/min). In contrast, K and V did not affect the renal clearance (177_+40 v s 185_+53 and 153+31 v s 173+51 ml/min, respectively} but reduced the biliary clearance of D by 33% (134-+57 v s 87+39 ml/min) and 43% (187_+89 v s 101-+55 ml/min), respectively. Conclusion: During maintenance treatment conditions, quinidine inhibited the renal and biliary clearance of digoxin, whereas quinine and verapamil reduced only the biliary clearance leaving the renal clearance of digoxin unchanged.

PHAI~IOCOKINETIC STUDIES J. Boldt, D. Kling, HA. Dieterich, G. Hempelmann Introduction: The calcium channel blocker nifedipine is widely used in the treatment of cardiovascular diseases. The new phosphodiesterase (PDE)-inhibitor enoximone seems to be promising in treating patients with impaired myocardial performance. Both substances are acting on slow Ca-- inward current and systemic elimination of these two substances is depending on oxidative drugmetabolizing enzyme activity and on hepatic blood flow. This study was performed to investigate pharmacokinetic and hemodynamic changes when both substances are given simultaneously under clinical conditions. Methods: 45 patients undergoing aorto-cordnary bypass grafting were randomly subdivided into 3 groups: group 1 received 0.5 mg/kg enoximone as a bolus after 40min of infusion of nifedipine (0.3 ug/kg'min; N+E-patients) group 2 received enoximone only in the same dosage (Epatients) group 3 received nifedipine only (Npatients). Plasma levels of nifedipine, enoximone, and enoximone-sulfoxide as well as various hemodynamic variables were measured till the end of the 0Peration. Results: Plasma concentrations of enoxzmone and enoximone-sulfoxide were not affected by nifedipine infusion and showed a comparable course in both groups. Nifedipine plasma level avaraged to values <15 ng/ml at the end of extracorporeal circulation. With regard to hemodynamics, enoximone induced comparable changes in Eand E+N-patients (increase in cardiac index, decrease in filling pressures) and even eliminated the negative hemodynamic effects of nifedipine (increase in right ventricular ejection fraction +26%). Conclusion: It can be concluded that no negative effects with regard to pharmacokinetics and hemodynamics are to be expected when these 2 substances are used simultaneously under clinical conditions. Abteilung ffr Anansthesiologie und Intensivmedizln, Universit~t Giessen, Klinikstr. 29, D-6300 Giessen

Department of Clinical Pharmacology and the Metabolism Unit, Karolinska Institute at Huddinge University Hospital, S-141 86 Huddinge, Sweden.

OP 42.05

OP 43.01

DOUBLE-BLIND STUDY ON THE INTERACTION OF O• WITH METOPROLOL IN HYPERTENSIVES M. Linde, H. Z e i d l e r , J. K~nig~ W. Kirch Some n o n - s t e r o i d a l , anti-inflammatory drugs (NSAIDs), part i c u l a r indomethacin, have been shown to antagonise effects of antihypertensive drugs including 8-adrenoceptor-blocking agents. Oxaprozin is a propionic acid de~vativewhich shows t y p i c a l anti-inflammatory p r o p e r t i e s in animals. A m u l t i centre double-blind study of 212 patients with c l a s s i c a l rheumatoid a r t h r i t i s showed that oxaprozin in a dose of 1200 mg d a i l y provided symptomatic r e l i e f at least comparable with t h a t afforded by a s p i r i n (ASA) 3900 mg d a i l y , but with fewer adverse e f f e c t s . Thus aim of the present study was to i n v e s t i g a t e a possible i n t e r a c t i o n between oxaprozin and the betablocker metoprolol. In a double-blind p a r a l l e l group comparison, 32 patients with a r t e r i a l hypertension (mean age 53.5 • 15.2 y r s . ; body weight 74.7 ~ 8.9 kg; ~ • SD), who were on steady state therapy with metopr~ Ioi lOOmg b.i.d.,were treated f o r a period o f 4 weeks with the NSAID oxaprozin 1200 mg o . i . d , or with placebo. In the placebo group, blood pressure values in supine posi t i on before addition of placebo were 134/86 mm Hg, a f t e r 14 days of placebo they were 136/85 mm Hg and f o l l o w i n g 4 weeks of placebo they were 137/86 mm Hg. Before administrat i o n of oxaprozin supine blood pressure was 132/82 mm Hg, f o l l o w i n g 2 weeks of oxaprozin i t was 143/83 mm Hg, a f t e r 4 weeks 135/81 mm Hg. A f t e r adjusting to baseline values, there were no s i g n i f i c a n t d i f f e r e n c e s in blood pressure between both treatment groups except f o r standing s y s t o l i c blood pressure at 14 days ( s i g n i f i c a n t l y higher values on oxaprozin with p = 0.004). Thus in conclusion, oxaprozin causes a tendency to an attenuation of the antihypertensive e f f e c t of metoprolol.

PREDICTION OF NONLINEAR PHARMACOKINETICS OF ORAL P~INDOPRIL FROM INTRAVENOUS DATA KR Lees and RJ MacFadyen ACE inhibitor pharmacokinetics are nonlinear. Features include a slow terminal elimination phase but rapid attainment of plateau trough drug concentrations; significant initial accumulation of drug with repeated low doses (less apparent with higher doses); and specific saturable tissue binding. Low dose iv infusions of perindoprilat produce concentration-time data which are better described by a model which assumes specific and saturable binding of drug to plasma and tissue proteins than by linear models. We have now applied the 2 types of model (nonlinear and biexponential) to oral concentration-tJ/re data. Using parameter estimates derived from iv studies, we have simulated the effect of repeated oral treatment and cc~pared this with observed values from both individual and group data. Median parameter estimates from 16 subjects given iv perindoprilat gave better predictions of accumulation and dose ratios than the standard model for 18 (different) subjects given repeated oral doses. Accumulation is expressed as the ratio of 24 h AUC for 7th:ist daily dose. Observed ratios: 1.43_+.34 (4rag perindopril), 1.07+.19 (8rag), 1.06+.16 (16rag) (P<0.05); nonlinear model predicted ratios: ~.36, i.Ii, 1.04; 2 compt, model predicted ratios: I.ii, i.ii, i.Ii. The nonlinear binding model also predicts substantial changes in drug clearance depending on rate of administration, a potential source of error in bioavail, ability studies. For example, the estimated AUC was 238 h.ng/ml for i0 h infusion of 1 rag, versus 160 h.ng/ml for bolus injection of 1 rag. Improved assessmant of the ptmrmacokinetics of ACE inhibitors may be provided by nonlinear tissue binding models. This may enhance understanding of the concentration-effect relationship. University Dept of Materia Medica, Stobhil i General Hospital, Glasgow G21 3UW, Scotland.

I. M e d i z i n i s c h e K l i n i k , C h r i s t i a n - A l b r e c h B - U n i v e r s i t ~ t Schittenhelmstr. 12, 2300 Kiel l , FRG

A 110

OP 43.02

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H U M A N P H A R M A C O K I N E T I C S OF O R - 4 6 2 , A N E W C A T E C H O L O-METHYLTRANSFERASE INHIBITOR P. J. Pentikltlnen, A. Vuorela, M. Jitrvinen, T. Wikberg and A. Gordin OR-462 (3,(3,4-dihydroxy-6-nltrobenzylidine)-2,4-pentanedione) selectively Inhibits catechoI-O-mathyltransferase and is potentially useful in Parkinson's disease in association with L-dopa therapy. To study the pharmacoklnatlcs of OR-462 single Intravenous (iv, 10 mg) and oral doses (po, 1 ms, 5 ms, 10 rag, 25 mg, 50 mg end 100 mg as capsules) were given to healthy male volunteers. OR-462 In plasma was quantitated by HPLC. Data were fitted using a nonlinear least square pharmacoklnetic program (NONLIN), two-compartment model for Iv and 50 mg and 100 mg po doses, one-compartment model fol; the smaller po doses, The results are shown In the following tables. IV administration (n = 6) V1 Vss Kel TI/24L Tt/2~ AUC CL (I) (I) (h -1) (h) (h) (hxng/ml) (mi/min)

Research Center, Orion Pharmaceutlca, P.O. Box 65, 02101 Espoo, and Third Department of Medicine, University of Helsinki, Helsinki, Finland

SINGLE-DOSE PHARMACOKINETICSTUDY OF IdB 1016, A NEW FLAVANOLIGNANE COMPLEX, IN MAN N. Barzaghi, E. Perucca, G. P i f f e r i and A. Crema IdB 1016 is a complex of phosphatidylcholine with s i l y b i n , the main active flavanolignane constituent in the extract of Silybum marianum (silymarin). In order to investigate the comparative pharmacokinetics of IdB 1016 and silymarin, plasma s i l y b i n levels were determined for up to 12 h following administration of single doses of both agents, equivalent to 360 mg s i l y b i n , to 9 normal volunteers. Doses were given o r a l l y in random order after an overnight fast, at intervals not exceeding 3 weeks. Silybin was measured in plasma by using a specific HPLC method. Following administration of silymarin, peak s i l y b i n levels ranging from 24 to 201 ng/ml (median 83 ng/ml) were attained usually within 2 h after dosing. The elimination h a l f - l i f e was short ( ~ 4 h) and s i l y b i n became generally undetectable (< 2 ng/~nl) within 8 h after dosing. AUC values (0-12 ~) ranged from 84 to 660 ng ml-- h (median 201 ng ml- h). After administration of IdB 1016, peak s i l y b i n levels (median 185 ng/ml,.range 67-3787 ng/ml) and_A~C values (median 804 ng ml -i h, range 236-5616 ng ml h) were s i g n i f i c a n t l y greater (P< 0.05) than those found after silymarin, whereas no s i g n i f i c a n t differences were found in time of peak or terminal h a l f - l i f e . These results indicate that the oral b i o a v a i l a b i l i t y of IdB 1016 (based on plasma s i l y b i n levels) is much greater than that of silymarin. Medical Pharmacology Division, Department of Internal Medicine and Therapeutics, University of Pavia, Piazza Botta I0, 27100 Pavia, I t a l y

OP 43.03

OP 43.05

PRELIMINARY PHARMACOKINETICS AND PHARMACODYNAMICS OF BWA589C IN HEALTHY VOLUNTEERS. P.E, Rolan, J. Ingram, W. Leavens, J.E. Parker, S.J, Gray, R. Wootton, J. Posner. BWA589C, (4(2-formyl-3-hydroxy-phenoxymethyl) benzoic acid interacts stoichiometrically with haemoglobin (Hb) causing a left shift of the haemoglobin-oxygen saturation curve (OSC). It is estimated that modification (MOD) of 15-30% Hh to the high-affinity form may inhibit sickling in sickle cell anaemia. We have administered BWA589C orally to 9 healthy, non-smoking, male volunteers, 2 receiving 200, 400 and 800mg and 4 receiving 1200, 2000 and 2800 mg. Heart rate (HR), blood presure (BP) and respiration rate (RR) were measured at rest and after graded supine cycle ergemeter exercise (40, 80, 120W for 3 min each) performed pre drug and at 4, 8 and 24 h. Drug concentrations in whole blood haemolysate was assayed by HPLC, and data fitted to a one compartment open model using NONLIN. %MOD was determined by visually comparing the obtained OSC with a set of reference templates. Blood count, biochemistry, coagulation and ex vivo platelet aggregation were monitored. All doses were well tolerated except for one subject receiving 1200mg who was withdrawn because of headache and vomiting. There were no important changes in resting or exercise HR, BP, or RR. Mean • s.d. Vd/f was 7.5 • 1.5 I; CL/f decreased with dose from 1,3 • 0.3 ml/min at 200mg to 0.61 • 0.2 ml/min at 2800 mg and corresponding t increased from 76.5 + 6.4 h to 160 • 29.5 h. After 256~mg Cmax of 324 i 68-#g/ml occurred at 22 i 7 h, with peak %MOD between 12 and 18%. Small reversible changes in reticulocyte count were observed in some volunteers at the two highest doses. BWA589C i n doses up to 2800 mg administered to healthy volunteers results in up to 18%MOD and is well tolerated. The drug is well absorbed and has a tl/2 of approximately 7 days. Human Pharmacology Unit, The Wellcome Research Laboratories, Beckenham, Kent, BR3 3BS, UK.

PHARMACOKINETICS OF DIGOXIN AND METABOLITES AFTER IV AND PO ADMINISTRATION AT TWO DOSE LEVELS IN HEALTH HUMANS D. Hartmann and P. H. Hinderling The goal of the study was to address three unsettled aspects of the kinetics of digoxin (D]: i. linearity of the kinetics. 2. extent of m e t a b o l i s m and metabolites. 3. completeness of label recovery. Three healthy young male volunteers received doses of 0.6 and 1.2 mg H-D iv and po. Total and individual radioactivities assignable to D and metabolites were assayed by specific methods using combined columnand thin layer chromatography. Compartment model independent and dependent standard methods were applied. Mean recovery of the label was complete [after iv administration: urine: 81.3%, feces: 17.1% of dose; after po administration: urine: 65.7%, feces: 31.6% of dose]. The kinetics of parent drug and metabolites were first order. After iv administration, total an~ renal clearances were on average 203 and 152 mL.min for D, respectively. Mean steady state volume of d i s t r i b u t i o n was 516 L and mean residence time was 42 h. Mean recovery of D and metabolites in urine was 75.5% and 6.2% of dose, respectively. Average renal clearance for dihydrodigoxin andldigoxigeninbisdigitoxoside was 79 and i00 mL min , respectively. The respective mean residence times were 35 and 53 h for the two metabolites. After po a4~inistration the renal clearance of D was 176 ml min- . Maximum concentrations of D were reached at 40 min and mean bioavailability was 0.67. Average recovery of D and metabolites in urine was 51.5% and 13.8% of dose, respectively. Water soluble derivatives and dihydrodigoxin were the major metabolites found. D e p a r t m e n t of Pharmacology, University of Basel, Klingelbergstr. 70, 4056, Basel, Switzerland

Mean SD

5.62 0.93

Dose (rag) C_ax

(ng/ml)

Tm:x (h) Tlj 2 abs (h) AUC (hxng/ml) F (%, n = 6)

7.98 1.08

3.65 0.55

0.16 0.02

0.69 0.10

492 93

340 60

PO a d m i n i s t r a t i o n (mean, n -~ 12*) 1 5 10 25 50

100

34 0.5 0.09 26 39

2570 0.6 0.36 2730 56

203 0.5 0.13 135 38

303 0.6 0.12 256 55

733 0.6 0.18 688 59

1490 0.6 0.15 1370 53

*including those 6 subjects who received the Iv-dose Thus, Iv OR-462 is rapidly distributed to a rather small volume and eliminated lastly. Gastrointestinal absorption of OR-462 is dose-independent and fast. BIoavallabillty of po 0 R - 4 6 2 is reduced most likely because of hepatic first-pass metabolism.

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OP 43.06

OP 44.02

POSSIBLE ENTEROHEPATIC CIRCULATION OF MORPHINE IN M A N J. H a s s e l s t r 6 m a n d J. S ~ w e In our investigations we have come across p h a r m a c o k i n e t i c b e h a v i o u r of m o r p h i n e a n d m e t a bolites which has not earlier been described. T h u s A U C ' s at s t e a d y s t a t e w e r e f o u n d t o b e g r e a t e r t h a n t h o s e a f t e r s i n g l e d o s e a n d 12 h o u r s a m p l i n g time. T h i s p r o m p t e d u s t o i n v e s t i g a t e pharmacokinetics of m o r p h i n e a n d t h e 3- a n d 6g l u c u r o n i d e s a f t e r o r a l (20 mg) a n d iv (5 mg) administration. I n a c r o s s o v e r s t u d y in h e a l t h y subjects, morphine and metabolites were determ i n e d in p l a s m a a n d u r i n e w i t h a s p e c i f i c H P L C method. The protocol was reviewed and accepted b y t h e e t h i c s c o m m i t t e e of H u d d i n g e U n i v e r s i t y H o s p i t a l . C l e a r a n c e (mean• was 19.0• ml/min/kg, Vd~ 2.9• i/kg, T I / 2 ~ 1 . 8 • h and bioavailability 27• T h e s e r e s u l t s a r e in agreement with earlier findings. However a new f i n d i n g w a s t h e p r e s e n c e of a s l o w l y d e c l i n i n g p h a s e , b o t h in t h e p l a s m a c o n c e n t r a t i o n v e r s u s t i m e c u r v e a n d in t h e u r i n a r y e x c r e t i o n r a t e v e r s u s t i m e curve. T h i s p h a s e w a s o b s e r v e d f o r both morphine and metabolites. The fact that the area under the curve during this phase relative to t o t a l a r e a w a s g r e a t e r a f t e r o r a l d o s e (80%) compared to intravenous administration (30%) is in a c c o r d a n c e w i t h e n t e r o h e p a t i c c i r c u l a t i o n of a high extraction drug like morphine. Indicat i o n s o f e n t e r o h e p a t i c c i r c u l a t i o n of m o r p h i n e h a s e a r l i e r b e e n s h o w n in a n i m a l b u t n o t in man. T h e p r e s e n c e of t h e s l o w l y d e c l i n i n g p h a s e o f m o r p h i n e a n d m e t a b o l i t e s in p l a s m a a n d u r i n e should be taken into account when planning f u t u r e i n v e s t i g a t i o n s on m o r p h i n e k i n e t i c s . Dept of Clinical Pharmacology, Karolinska Institute, Huddinge University Hospital, Huddinge, Sweden

DRUG USE IN PREGNANCY. PRELIMINARY RESULTS FROM NORWAY AND SWEDEN I. Mathesont P. S~derman and the Collaborative Group on Dru~ use in Pregnancy Trends in drug use during pregnancy can be helpful f o r scrutinizing the quality of health care in pregnancy. Drug use in pregnant women from Norway (N) and Sweden (S) were compared with that in other countries (WHO) with the aim to study differences in (1) choice of drug therapy (2) pregnancy complications. Methods: 482 women from 2 hospitals in N and 213 women from 2 hospitals in S were interviewed I-5 days after delivery. The women gave birth during the end of 1987/first of 1988. Information collected was intakes of drugs, tobacco, alcohol, coffee, demographic data, pregnancy cours~ and outcome. These data were compared with preliminary results of the total number of 7479 women (as per Nov 88) from 10 countries participating in the collaborative study under the auspices of WHO. Results: The proportion of women who used at least one drug incl. iron/vitamins was somewhat higher in N than in S (91 vs 85%) and WHO (86%). The mean number of drugs per drug taker in N, S and WHO was 2.7, 2.0 and 2.6, respectively. The most common medications in pregnant women were antianemics, vitamins, 62-stimulants, analgesics, antacids. Antiinfectives were more common in N than in S (33 vs 11%) while analgesics were more common in S than in N (43 vs 31%). B2-stimuLants were more common in WHO and S than in N (14 and 9 vs 3%). The prevalence of smoking in pregnancy was higher in N than in S (35 vs 26%). About I/6-I/5 of the mothers in N and S were hospitalized at least once during pregnancy. Conclusions: The study indicates that 80-90% of pregnant women receive medication. However, there is a wide variation in the drug pattern e.g. 62-stimulants, antiinfectives, antacids and analgesics. These important health issues will be further discussed. Dept Pharmacotherapeutics, Univ of Oslo, Norway, Dept Pediatrics, Ostersund Hosp, ~stersund, Sweden and Inst Pharmacol Res "Mario Negri" (M Bonati), Milan, Italy

OP 44.01

OP 44.03

DISORDERS AND DRUG USE IN MOTHER/INFANT PAIRS DURING BREAST-FEEDING. A COMPARISON BETWEEN SWEDEN AND NORWAY. P S~derman, I Matheson, HK Blomquist The extent of drug therapy f o r common disorders in the puerperal period was investigated in mothers and t h e i r i n f a n t s during the f i r s t 4 months of l i f e . A d d i t i o n a l l y sociodemopraphic f a c t o r s , data about breast-feedi ng, c i g a r e t t e s , alcohol and coffee were recorded. The aim was to r e l a t e disorders and drug use to the above f a c t o r s . Methods: Mothers giving b i r t h during a i-month period (n=229) in Ostersund and Ume~ (Sweden) and mothers giving b i r t h during a 3-month period (n=885) in OSlD (Norway) f i l l e d in a questionnaire. The response rate varied (78-92%) between the 3 centres. Results: The rates of breast-feeding at discharge from hospital and at 4 months post partum were 98 and 73% in both countries. The percentage with at least one d i s o r d e r were higher in Ostersund/UmeA than in Oslo both f o r mothers (94 vs. 81%) and f o r i n f a n t s (92 vs. 74%). In both countries 2/3 of the mothers used at least one drug, mostly analgesics, r e s p i r a t o r y agents and a n t i h e morrhoidals. Norwegian i n f a n t s more often than Swedish ones (58 vs 32%) received a drug, mostly a n t i c o l i c agents, nose drops, a n t i p y r e t i c analgesics. Infants with c o l i c , r e s p i r a t o r y symptoms and fever were more seldom treated with drugs in Ostersund/Ume~ than in Oslo. Smoking among puerperal women was less prevalent in Ostersund/Ume~ than in Oslo (18% vs 40%). Conclusion: Disorders were f r e q u e n t l y reported in the post partum period both in the mothers and in t h e i r i n f a n t s . Despite a higher incidence of symptoms, Swedish mothers and i n f a n t s in t h i s study received fewer drugs than the Norwegians did. Some explanations w i l l be provided. Departments of Pediatrics in Ostersund Hospital,Ostersund and in Regional Hospital, U n i v e r s i t y of UmeA, Sweden, Department of Pharmacotherapeutics, U n i v e r s i t y of Oslo, Norway.

DRUG USE IN CHILDREN PARENTS' EXPERIENCES AND ATTITUDES E.-L. Toverud r M. Andrew t K. Moss Ofstad t A.-M. Timenes The present study is the second part of a major project on drug use in children. The first part has provided nationwide information on drug prescribing to 0-12 year old children (I). The aim of the present study has been - to obtain information on the exten~ of and indications for drug use in children, with special emphasis on antibiotics and antipyret~cs, and - to gain knowledge of parents' experiences and attitudes regarding the use of drugs in their children. Children aged I-3 years in two districts in the Oslo area were randomly selected from health centre records. This age group was selected because it represents the age where children are administered most drugs (I). Approximately 80% of the parents, representing 190 children, agreed to be interviewed in their homes. They were asked which drugs the children had used, the dosage form, the indication for use, practical medication, parents' own drug use etc. Preliminary results indicate that 15% of the children were using drugs in connection with chronic diseases. As regards antibiotics, 37% of the children had received at least I course during the last 6 months, 15% had received 2 or more courses. Erythromycin was the antibiotic most frequently used. 72% of the children had received antipyretics during the last 6 months, and paracetamol was used in 94% of these cases. Advice on choice of antipyretics had mostly been given by community nurses, doctors and pharmacies. The results are in good agreement with data from the first study. The most important new information is on the use of OTC-drugs, the use of drugs over time and practical aspects of child medication as experienced by parents. I. Andrew M, Toverud E-L. Drug use among Norwegian children. Xth International congress of pharmacology, Sydney, August 1987 (Abstract no P613) Department of Pharmacotherapeutics, University of Oslo, P.O. Box 1065 Blindern, N-0316 Oslo 3, Norway -

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OP 44.06

OP 44.04 DRUG PRESCRIBING IN ELDERLY ZS.Bustami, A. Muchtar, AT Djamil Department of Clinical Pharmacology University of Indonesia School of Medicine Jakarta, Indonesia In our teaching hospital, Dr. CiptoMangunkusumo General Hospital, Jakarta, elderly patients were approximately 6,5% of total adult patients (> 12 years old) ad mitted in 1988. Stroke, cancer, cataract, prostate hypertrophy, congestive heart failure, myocardial infarction, hernia, liver cirrhosis, traffic accident, and bone fracture were major diseases which brought them to the hospital. It was found that hypertension, ischemic heart disease, and diabetes mellitus were diagnosed as underlying diseases, while nosocomial infections during hospitalization afflicted some of the patients. Medications frequently given to these patients were antibiotics, cardiovascular drugs, vitamins, gastrointestinal drugs, vasodilators, hemostatics, and respiratory drugs. On the average, every patient received 4.6 drugs during their stay in hospital (range 0 - 26). By matching diseases and prescription pattern grossly, it was found that antibiotics, vitamins, vasodilators, and hemostatics were used excessively. Additionally, in some Cases, polypharmacyshowed potential drug interactions, while potential toxicities due to relatively high doses were also identified. We concluded from this study and from literature surveys, that excessive use of drugs in the elderly is a worldwide problem which poses the elderly to unnecessary risk and cost.

OP 44.05 DRUG-INDUCED NEUTROPENIA B.L. Strom, J.L. Carson, R. Schinnar, G. Maislin, and M.L. Morse

ANALYSIS OF THE GEOGRAPHIC DIFFERENCES IN THE UTILIZATION OF HYPNOTICS, SEDATIVES, AND MINOR TRANQUILLIZERS IN SWEDEN B. Westerholm, U. Bergman, and D. Lee As part of an ongoing process, currently available p h a r m a c e u t i c a l sales and p r e s c r i p t i o n databases were e m p l o y e d to review the utilization of hypnotics, sedatives, and m i n o r tranquillizers. Sales figures suggest that the use of this therapeutic class has been stable over the last 15 years. However, there are considerable geographic differences: sales in Stockholm (60 D D D / 1 0 0 0 inhab/d) is much lower than in the counties with the two other large cities of Sweden, Malm6 (85 D D D / 1 0 0 0 inhab/d) and G o t h e n b u r g (80 D D D / 1 0 0 0 inhab/d). Data from the Diagnosis and Therapy Survey and the p r e s c r i p t i o n survey indicate differences in p r o v i d e r (psycMatrist vs general practitioner) as sourer; of prescriptions; differences in the decision to issue a prescription in the treatment of mental disorders; and differences in treatment r e g i m e n s (strength and p a c k a g e size). An association b e t w e e n increased negative o u t c o m e s (abuse, overdosage, and suicide) and increased sales data has been suggested in other studies. The evaluation of the impact of the currently observed differences in prescribing and use on actual patient benefit constitutes the next and necessary stage of the therapeutic audit. National Corporation of Pharmacies and D e p a r t m e n t of Clinical Pharmacology, Karolinska Institutet at Huddinge University Hospital, Huddinge, Sweden

OP 45.01 E. Sim,

A case-control study was performed using Medicaid billing data from the states of Minnesota, Michigan, Florida, Ohio, Missouri, and Nebraska. All patients with a diagnosis of neutropenia (ICD-9-CM code 288.0) were compared to four controls per case, matched for age, sex, state, and pregnancy. Patients with any diagnosis of cancer or receiving c y t o t o x i c drugs were excluded. Drug exposure was assessed 30 days prior to the diagnosis of neutropenia in the cases and during the identical time period in the controls. Discharge summaries and laboratory tests were reviewed in a sample of neutropenic patients, confirming the diagnosis of neutropenia in 97% of the cases. Comparing 2,647 inpatient and outpatient cases to 10,037 controls, calculating odds ratios (OR) and 90% confidence intervals, associations were demonstrated for the following selected drugs: anti-thyroid drugs: infinity (5.9-infinity), "captopril: 3.8(1.2-11.7), NSAIDs: 1.7(1.42.0), phenytoin: 3.3(2.6-4.1), procainamideSR: 7.6(1.4-56.5), and valproic acid: 5.4(3.1-

9.4). 2 2 5 L NEB/S2, Clinical Epidemiology Unit, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6095.

MEASIIREMENTS OF PLASMA NORADRENALINE (NA) AND 3,4,-DIHYDROXYPHENYLGLYCOL (DOPEG) AS A TOOL TO STIIDY SYMPATHETIC NI~RVOI.IS FUNCTION K.-H. Graefe, J. Ludwig and T. Halbrtigge Studies in isolated organs of various species have shown DOPEG to be the main presynaptic metabolite of NA. We have studied the relation between plasma DOPEG and NA under various conditions in healthy subjects. Graded orthostasis induced by 30 min of quiet sitting and standing caused increases in the forearm venous plasma concentration of DOPEG which were linearly related to increases in the NA concentration. The slope of this relation (b R) was about unity (n=21). Inhibition of neuronal uptake by pretreatment with desipramine (DMI; 1.5 mg kg -1 p.o. 3 h prior to testing) abolished the DOPEG response to orthostasis. Similar observations were made in 7 subjects who underwent 2 consecutive constant-rate i.v. infusions of isoprenaline (ISO; 30-40 and 80-120 pmol kg -I min-1 for 25 min each). Steady-state concentrations of ISO, NA and DOPEG were determined in mixed central venous plasma. It was found that ISO-induced, concentrationdependent increases in plasma NA were accompanied by increases in plasma DOPEG. This plasma DOPEG response was again abolished by DMI. Hence, increases in plasma DOPEG brought about by increases in sympathetic activity are presynaptie in origin. In a 3rd study (involving 4 subjects), the effect of NA infusion on plasma DOPEG was examined. NA was infused i.v. for 2 consecutive, 30-min periods at constant rates of 0.44 and 0.88 nmol kg -1 rain -1, and NA and DOPEG were measured in arterial plasma. In this study, large increases in NA concentration caused 'very small increases in DOPEG concentration. The increase in plasma DOPEG relative to that in plasma NA averaged 0.06, a slope value (bl) which was much smaller than b R. From these 2 slopes, the factor by which the NA concentrations in plasma and noradrenergic neuroeffector junctions differ was obtained from the square root of bR/bl; it amounted to about 4. (Supported by the DFG and the Bayer AG). Institut f~ir Pharmakologie und Medizinische Poliklinik der Universit~it WUrzburg, D-8700 W[irzburg, FRG

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ISOPRENALINE INFUSION-INDUCED INCREASE IN LYMPHOCYTE~2ADRENOCEPTOR DENSITY: A SPLEEN-DEPENDENT,~ROCESS. ,) L.J.H. van Titsi~M.C. Michell~A. Soleman ", F.-W. Eigler , H. Grosse-Wilde ', M. Happel ' and O.-E.Brodde

EFFECTS OF SMOKING AND NICOTINE CHEWING GUM ON CAPILLARY AND VENOUS ADRENAUNE H.Baumgartner, G.Hochleitner, R.Pfister, G.l_~cke, H.HOrtnagl, V.G~nther, W. U. Saewe, H.Sl&ckler, I. Wedermann Ten moderately dependent male smokers (age<30 yrs) were studied following an open randomised balanced cross-over design, On "S-DAY' 1 cigarette of their "usual" brand (mean nicotine content: ~ling) was smoked for 5 rain, on =N-DAY" 1 piece of nicotine chewing gum (NICORETTE-2 mg; Pharmacia LEO) was chewed for 20 min. We present results obtained from seated subjects at the following times: 35 min after venipuncture ,BASAL'; values ('PEAK"), obtained on S-DAY at 5 or 10 min after the beginning of smoking, on N-DAY at 5, 10 or 20 rain after the beginning chewing gum; 40 rain after the beginning of smoking/chewing gum ("AFTER'). Arterialized capillary (cepAD) and forearm venous (venAD) plasma catecholamines were analysed

Isoprenaline-infusion causes in healthy volunteers a rapid increase in lymphocyte ~-adrenoceptor (AR) density (Tohmeh & Cryer, JCI 65:836,i980). To study the mechanism underlying this phenomenonwe compared the effects of isoprenaline-infusion on ~-AR density in lymphocyte subsets in 10 male healthy voluhteers and in 5 male patients who had undergone splenectomy because of Hodgkin's disease (4 patients) or trauma (I patient). In healthy volunteers isoprenaline-infusion (3.5; 7; 17.5; 35 and 70 ng/kg/min for 5 min each) caused an about 150% increase in lymphocyte ~9-AR density; concomitantly lymphocyte subsets distribution was markedly altered: T~I~- and NK-cells increased, whereas Th-cells decreased.HS~ver, at the end of the infusion, ~9-AR density had increased about 2 fold in a11 lymphocyte ~ubsets (pan T-, pan B-, T~/~- and Th-cells,7~but was not changed in monocytes or pI&%elets. I~ contrast, in the 5 splenectomized patients, isoprenaline infusioninduced increase in lymphocyte #9-AR density was markedly attenuated (% increase: about 40~ and lymphocyte subsets distribution was not changed - despite a 2 fold increase in NK-cells. These results indicate that the isoprenalineinduced increase in lymphocyte ~9-AR does not represent receptor regulation, but is a lySphocyte specific phenomenon; i t is obviously caused by a release of lymphocyte subsets from the spleen into the circulation and/or by an exchange of lymphocyte subsets between the spleen and the circulation, whereby freshly released splenic lymphocytes seem to have more ~2-AR than those in the circulation. Supported by the SANDOZ-Stiftung f. Therapeut. Forschung. Med.Klinik & P o l i k l i n i k , Abt. Nieren- & Hochdruckkrankel *) Abt. Allgemeine Chirurgie and +) Inst. f. Immungenetik, Universit~tsklinikum, Hufelandstr. 55, D-4300 Essen, FRG.

radioenzymatically. There was a transient rise of capAD (see table) and HR caused by smoking (mean HR: "PEAK": 92 p<0.0t vs "BASAL': 68 and "AFTER": 72). Compared to smoking, chewing nicotine gum caused a smaller peak increase of HR ("BASAL': 66 p<0.01 vs "PEAK": 78) yet no change in capAD. Throughout the test venAD levels remained unchanged (-100 pg/ml) and significantly lower than capAD. "BASAL" "PEAK" "AFTER" S-DAY

164

225*

168

capAD

(97-357) (145-444) (122-308) N-DAY 152 159 165 (93-260) (102-305) (76-350) Statistical test: ANOVA (S-DAY: n=9; N-DAY: n= 10). Values (pg/ml) a r e means (ranqe); * different from "BASAL"and "AFTER": p
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METOPROLOL AND ACETTLSALICYLIC ACID - A COMBINATION THAT PREVENTS SMOKING INDUCED PLATELETACTIVATION I N MAN

A COMPARISON OF THE DURATION OF ACTION OF INHALED SALMETEROL AND SALBUTAMOL USING I-USTAMINE INDUCED BRONCHOCONSTRICTION J.G, Maconoehi_e, L. Denver and H. Hass_ani Salmeterol has been shown in both animals and man to be a selective B2-adrenoceptor agonist more potent than salbutamol and with a longer duration of action (Ball et al. 1987 Br. J. Clin. Pharmac. 92: 746P and Ullman et al. 1988 Thorax 43(9) 674-678). This study was designed to investigate further the duration of action of inhaled salmeterol by comparing its effect with inhaled salbutamol. Eight healthy male subjects known to respond to inhaled histamine participated in the study. A double-blind, cross-over study was carried out on 4 separate days with intervals of at least 6 days. Treatments investigated were salbutamol 200pg, and salmeterol 12.5, 50 and 100pg, all from metered dose inhalers. Order was determined by two randomised 4 x 4 Latin squares. A histamine challenge test was carried out before each treatment and 1, 4, 8 and 12 hours after treatment. The concentration of histamine which resulted in a 15% fall in FEV z (PDls) was estimated from the graph of FEV 1 v. log dose histamine. A weighted average for both pre-histamlne FEV z and PDzs over the twelve hours was calculated and analysed using analysis of covariance. The sum of squares due to treatments was examined to ascertain response versus log dose linearity. The weighted average of prey-histamine FEV 1 for 50 and I00pg salmeterol (3.71s and 3.79s was significantly greater than that for 200pg salbutamol (3.56s (P<0.05) and there was a linear reIationship between FEV 1 weighted average and log dose of salmeterol (P<0.01). The PDls weighted average was significantly greater for 50 and 100pg salmeterol (10.6 and 11.7rag/m1 histamine) compared to 200pg salbutamol (6.9mg/ml histamine) (P<0.05). There was evidence of a linear relationship between PDls weighted average and log dose of salmeterol (P<0.09). This study confirms the results in previous studies with salmeterol, that compared to salbutamol the drug is a long acting bronchodilator and the duration of action is dose related. Glaxo Group Research, Ware, Hefts. SG12 ODP England.

K.-H. Grotemeyer , C.Harking D~partment of Neurology, Unlversity of M0nster, F.K.U. It is assumed that smoking Ss a poten t factor in promoting ar~eriosK• The ro• or actlvateo platelets in arteriosklerosis is widely acq@pted. Smokinq activates, platelets ana accoralng to Davis (i) it may De accepted tha~ acety%saiicylic~acld (ASA) does not inhiblt smoking inaucea plate• activation. The betablocKer metoprolo• seems to be effective in p r e y e n t i n g . ~ r o m vaw death especially in smokers suffering zrom hypertension (~i. In oraer to oetermine the effect ot ASA and mgtoprplol on smokin~ induced platelet-activatxon the cnanges,oz F • (PR) (2) were measurea in 20 healthy smokers before treatment ,atter,a~ninistration of 500 mg ASA, 200 mq me$opro4ol and 200 mg metoprolol+ 500 mg ASA. R a i s l n g oZ PR without treatment was siqnificant (W%Icoxon paired test) with p<0.0003, unaer ASA wxth p
Kl~nik und PQliklinik A•

f~r Neurologie der WWU Munster

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PLASMA CATECHOLS AND RENAL SYMPATHETIC NERVE ACTIVITY

CODEINE AND PARACETAMOL FOR RELIEF AFTER TOOTH EXTRACTION. W S N i m m o , L Wyld, C Y e o m a n

M. Garry, A.D. Starosta, P.C. Chang, G. Eisenhofer, Z. Zukowska-Grojec, R. Stull, N.R. Keiser, I.J. Kopin, D.S, Goldstein ~e measured simultaneously renal sympathetic nerve activity (RSNA) and a~terial and renal venous concentrations of the sympathetic neurotransmitter norepinephrine (NE), its precursor dihydroxyphenylalanine (dopa), and its intraneuronal metabolite dihydroxyphenyglycol (DHPG) in anesthetized, adernaldemedullated Sprague-Dawley rats. intravenous administration of nitroprusside (NP) decreased mean arterial pressure (MAP) significantly by 43% and increased RSNA by 76~, arterial levels of dopa by 96%, NE by 326%, and DHPG by 141~. Intravenous administration of phenylephrine (Ph) increased MAP by 24% and decreased RSNA by 32~; arterial levels of dopa were unchanged, NE decreased by 26~ whereas levels of DHPG increased by 81~. Ganglionic blockade by chlorisondamine decreased RSNA by 55%; arterial dopa concentrations were unchanged, NE decreased by 37%, and DHPG concentrations increased by60~. The clearance of DHPG from arterial plasma was prolonged by Ph-induced hypertension and by NP-induced hypotension. Changes in arterial NE levels were closely correlated with changes in directly recorded sympathetic activity, changes in dopa levels appeared to reflect changes in catecholamlne biosynthesis, and changes in plasma DHPG seemed to depend both on reuptake of NE and on hemodynamic factors affecting DHPG clearance. The results demonstrate that plasma levels of catechols can reflect different aspects of sympathoneural function during reflexive manipulations of sympathetic outflow.

OF PAIN

T a b l e t s c o n t a i n i n g c o d e i n e (C) a n d p a r a c e t a m o l (P) are used frequently. We compared 5 preparations containing P alone or P + C used to relieve pain after minor oral surgery. After g e n e r a l a n a e s t h e s i a , 60 p a t i e n t s w e r e a l l o c a t e d randomly to receive two tablets of P a n a d o l Soluble (P), Panadeine Co (P+C), Paracodol (P+C), Solpadeine (P+C) o r So]padeine Forte (P+C). The last two contain caffeine also. A n a l g e s i a w a s m e a s u r e d d o u b l e b l i n d f o r 90 m i n u s i n g v i s u a l a n a l o g u e scores. Plasma P and C concentrations w e r e m e a s u r e d b y HPLC. T h e m e a n s u m of t h e p a i n i n t e n s i t y d i f f e r e n c e s (SPID) was significantly greater after Solpadeine F o r t e (331) t h a n a f t e r t h e o t h e r p r o d u c t s (205 - 261). T h e p a i n r e l i e f w a s m a x i m a l at 45 to 60 minutes. Solpadeine Forte had significantly higher C concentrations than the other C containing compounds. (30 m g d o s e c o m p a r e d w i t h 16 mg). Mean (SEM) time to peak P concentrations was shorter after Solpadeine F o r t e (15 (0) min) t h a n a f t e r P a n a d e i n e Co (32 (7) rain). I n v e r e s k C l i n i c a l R e s e a r c h , E d i n b u r g h E H I 4 4AP. U n i v e r s i t y of S h e f f i e l d , S h e f f i e l d SI0 2RX.

NINCDS building 10 5N214 N.I.H. Bethesda MD 20892 USA.

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PATIENT-CONTROLLED ANALGESIA BY THE ORAL ROUTE: MORPHINE ADMINISTRATION IN CANCER PATIENTS. L. L. Gustafsson, M. Isaksson and C. Alm

D E C R E A S E D P A I N IN T H E I S C H A E M I C F O R E A R M T E S T BY THEOPHYLLINE. B. J o n z o n , C. S y l v @ n a n d L. K a i j s e r . To study the hypothesis that endogenous adenos i n e is a m e d i a t o r of t h e i s c h a e m i c p a i n s e n s a tion theophylline (5,5 m g of t h e e t h y l e n d i a m i n e s a l t / k g iv) w a s t e s t e d in a p l a c e b o c o n t r o l l e d double-blind cross-over study (Placebo/theophylline/placebo or Placebo/plaeebo/theop h y l l i n e ) in 5 h e a l t h y v o l u n t e e r s . Ischaemic work was performed with a spring l o a d e d h a n d e r g o m e t e r (i Hz). T h e p a i n s e n s a t i o n w a s c o n t i n o u s l y r e p o r t e d u s i n g t h e B o r g scale. Blood flow was measured by occlusion plethysmography. Pain was reported 18• s after starting the ischaemic work and increased continously to a maximum after 129• s (placebo). Theophylline (plasma concentration 75• ~mol/L) d e c r e a s e d t h e p a i n s e n s a t i o n in r e l a t i o n t o w o r k i n g time. W i t h t h e o p h y l l i n e 12• m o r e (p
IV administration of opioids by patient-controlled techniques has shown large interindividual variability in dose requirements in the postoperative period. We studied if this concept can be used for oral administration of morphine-HCl (mo).Lung cancer patients with metastases (n=8,age 59• years) were recruited. They were unrelieved on high daily doses of acetacetaminophen (>4g) in combination with either dextropropoxyphene (>400mg)or codeine (>300mg). A thin gastrointestinal feeding tube was placed in the stomach or duodenum and connected to a pump for self-administration of me. The maximal dose a patient could take was 30mg every 15 min.The study lasted for 54• II h. One person was withdrawn from the study for technical reasons.Venous blood samples were drawn just before demand of a dose and at regular intervals thereafter. Plasma me levels were assayed by HPLC. Analgesia was monitored by the visual analogue scale (VAS,0 mm--no pain,100 mm=unbearable).Self-administered doses varied between patients (3.8-17.4 mg/h).In each patient it was consistently higher during the first h (20-40 mg) than later. Me cone when a new dose was taken varied between patients (8-61,12-100 and 14-240 nmol/L on day I, 2 and 3, resp.). This minimum analgesic cone did not increase over time. Time to maximal conc of me after dose was 26.3 • 17.4 min on day 1 with no change over time. No patient required supplementation of opioids by the IV route. In 4 out of 7 patients VAS levels were either low during the whole study (10-20 mm) or decreased over time (0-50 mm on day i, 10-20 on day 3). In the other 3 patients VAS-levels varied during all days (from maximal 30-50 mm to 10-15 mm at 15-30 min after dose). The concept of patient-contrOlled analgesia by the oral route could be used to rapidly achieve analgesia whic h is not feasible when fixed doses of opioids are prescribed. This technique should be useful to study dose-potency between various administration routes. Department of Clinical Pharmaeology,Karolinska Institute at Huddinge University Hospital,S-141 86 Huddinge,Sweden.

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CLINICAL PHARMACOLOGYOF TWONEW PANCURONIUMANALOGS F.F. Foldes, H. Nagashima, H.D. Nguyen and D. Duncalf Recently 2 analogs o f pancuronium (PANCUR), vecuronium (VECUR) and pipecuronium (PIPECUR), became a v a i l a b l e f o r production of muscular relaxation in anesthetized patients. The ED90 of VECUR, PIPECUR and PANCUR in patients under balanced anesthesia were 43.7, 33.9 and 49.8 ~g/kg r e s p e c t i v e l y . The neuromuscular (NM) e f f e c t s of comparable doses of the 3 MR used f o r the f a c i l i t a t i o n of tracheal i n t u b a t i o n , summarized in the t a b l e , i ndi cat e t h a t the maximal NM e f f e c t and onset time ( f o r d e f i n i t i o n s see t a b l e ) of the 3 MR are s i m i l a r . The c l i n i c a l duration and recovery rates o f PIPECUR and PANCUR were much longer than those o f VECUR. The c l i n i c a l duration of 15 Ng/kg repeat doses of PIPECUR 51.0• and PANCUR 52.9• min. were also longer than those o f VECUR 13.8• m i n . The NM e f f e c t of the 3 MR could be equally well antagonized by a n t i c h o l i n e s t e r a s e s . Intubating doses of PANCUR increased heart rate by about 20% and s y s t o l i c blood pressure by about 10%. VECUR or PIPECUR had no c i r c u l a t o r y or other side e f f e c t s . Because o f the absence of side e f f e c t s , under most circumstances, VECUR and PIPECUR are preferable to PANCUR f o r the provision of s u r g i c a l relaxation. VECUR P I P E C U R PANCUR Dose (Ng/kg) 100 80 i00 Maximal block (%) >100 93.3•167 97.8• Onset time (min)* 5.9• 3.6• 3.7• C l i n i c a l duration (min)t 36.3• 110.5• 115.8• Recovery rate (min)r 14.3• 44.5• 41.3• * Time from s t a r t of i n j e c t i o n to maximal e f f e c t . + Time from the s t a r t o f i n j e c t i o n to recovery o f P to 25% o f c o n t r o l . r Time f o r recovery of NM transmission from 25 to 75% of control. w All values are expressed as mean • SEM. Montefiore Medical Center, 111 East 210th Street, Bronx, NY 10467

E F F E C T S OF T R A N S D E R M A L S C O P O L A M I N E ON P H A R M A C O - E E G (PEEG), W R I T I N G P R E S S U R E A N A L Y S I S , AND P U P I L L O M E T R Y IN MAN S. S e h w a b e , B. E n s s l i n - H a a s i s ~ R. Schulz, K. H. A n t o n i n , and P. R. B i e e k Transdermal scopolamine (TTS-Scopoderm | is an e f f e c t i v e t r e a t m e n t of m o t i o n sickness. A d v e r s e effects i n c l u d i n g toxic p s y c h o s i s have infreq u e n t l y been reported. For this reason, CNS effects were e x a m i n e d in a r a n d o m i z e d , p l a c e b o c o n t r o l l e d , d o u b l e - b l i n d , c r o s s o v e r study in 7 h e a l t h y v o l u n t e e r s . Each v o l u n t e e r r e c e i v e d one T T S - s e o p o l a m i n e or T T S - p l a c e b o every 3 d for 3 c o n s e c u t i v e courses. PEEG, w r i t i n g p r e s s u r e a n a l y s i s and p u p i l l o m e t r y were done on d i, 2, 4, 7, 9, and i, 2 and 6 d after r e m o v a l of TTS. PEEG was a n a l y z e d for r e l a t i v e and a b s o l u t e p o w e r s p e c t r a (RPS and APS), r e s t i n g r e c o r d (RR) and r e a c t i o n time (RT). Results: O c c i p i t a l : Delta (<3.5 Hz--~ A l p h a ( 9 . 5 - 1 0 . 5 Hz +14~ ( R E - A P S ) -20~ (RT-RPS +169 (RT-APS) + 9~ ( R T - ~ E S ) Frontal: Beta (18.5-20 Hz) A l p h a (8.5-9.5 Hz -ll~ ( R T - R P S ) - 7~ ( R T - R P S These results are similar to a previous study with i.m. scopolamine (W. G. S a n n i t a , Neurop s y c h o b i o l o g y 17, 199, 1987). W r i t i n g p r e s s u r e analysis showed no Changes. P u p i l l o m e t r i c c h a n g e s and s p o n t a n e o u s l y r e p o r t e d side e f f e c t s were c o n s i s t e n t w i t h a n t i c h o l i n e r g i e effects. Conclusion: Transdermal scopolamine directly a f f e c t s the CNS. PEEG c h a n g e s were i n d i c a t i v e of d e c r e a s e d v i g i l a n c e , a l t h o u g h s y m p t o m s of t i r e d n e s s were not reported. Human P h a r m a c o l o g y I n s t i t u t e , C I B A - G E I G Y GmbH, W a l d h ~ r n l e s t r . 22, D-7400 T ~ b i n g e n , FEG

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A CLINICALCOMPARISON OF THE NEUROMUSCULAR BLOCKING EFFECT OF DEPOLARIZING AND NONDEPOLARIZING MUSCLE RELAXANTS IN CESAREAN SECTION T. Aoki, K. Watanabem M. Nakamura and K. Fnkushima The currently used muscle relaxants all are available for cesarean section anesthesia. They have different degrees of action and placental transfer. Which was the most useful and safest relaxant in parturients, has been poorly documented. The aim of the present study was to compare neuromuscular blocking effects of depolarizing and nondepolarizing muscle relaxants and to determine clinically the most desirable relaxant for parturients. After institutional approval and informed consent were obtained, 38 healthy women undergoing elective cesarean section were studied, gnccinylcholine ( SCh ) img/kg ( n=6 ), vecuronium ( VB )0.1mg/kg ( n=ll ), d-tubocurarine( dTc ) 0.5 mg/kg ( n=9 ) or paneuronium ( PB ) 0.08mg/kg ( n=6 ) was administered IV under general anesthesia. The neuromuscular blockades produced by the relaxants were evaluated with the evoked compound electromyogram. In 6 patients, blood samples were drawn from maternal radial artery and fetal umbilical vein after IV administration of VB 0.1mg/kg. The plasma concentration of VB was determined with high performance liquid chromatography. As the results, onset time and duration of action were i.00 + 0.07, 6.89 + 0.30 min in SCh-group, 2.18 + 0.14, 41.5 $ 3.1 min in VB-group, 2.44 + 0.17, 57.0 + 2.4 min in dTc-g~oup and 3.22 + 0.40, 68.7 +-6.5 min in PB-group. The concentrations of VB in maternal-blood at delivery were 180 to 490 ng/ml and those in the umbilical vein were very low ( less than 50 ng/ml ) at delivery. The onset of SCh was so rapid that it supplies the best intubating condition in the shortest period of time, however, it's duration of action was too short. VB may be ideal relaxant for patients undergoing cesarean section because of it's shorter onset time, intermediate duration of action and minimal placental transfer, comparing to other nondepolarizing muscle relaxants. Department of Anesthesiology, NationaiDefense Medical College, 3-2 Namiki Tokerozawa, Saitama 359 Japan

Direct evidence for a dilator role of endothelium-derived relaxing factor (EDRF) in conscious man. P.J.T. Vallance, J.G. Collier We have examined the role of the vascular endothelium in mediating vasodilatation in human dorsal hand veins in vivo. Noradrenaline pre-constricted dorsal hand veins with intact endothelium relaxed to both acetylcholine (ACh) and glyceryl trinitrate (GTN) whereas following endothelial denudation with distilled water, relaxation was only seen in response to GTN. Vessels denuded of endothelium developed increased tone (50% constriction) which reversed gradually, over 2 weeks, a time at which the response to ACh had returned. Thrombosis developed in 2 vessels within 24 hours of denudation. These results suggest that continuous release of EDRF inhibits venous tone and is important in preventing thrombosis in man. These findings confirm and extend the observations on previously made in laboratory studies. Dept. Pharmacology. St George's Hospital MedicalSchool, London SWI7 ORE, UK

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OP 47.04

E N D O T H E L I N : A P O T E N T V A S O C O N S T R I C T O R WITH P R O L O N G E D ACTION IN F O R E A R M R E S I S T A N C E V E S S E L S AND HAND V E I N S IN MAN D Webb, N Beniamin. J Clarke. J Cockcroft. and S L a r k i n E n d o t h e l i n (ET) is a 21 amino acid peptide s y n t h e s i z e d by c u l t u r e d m a m m a l i a n v a s c u l a r endothelial cells. S t u d i e s in vitro s u g g e s t t h a t ET is a p o t e n t constrictor of v a s c u l a r s m o o t h muscle, m a y be t h e final m e d i a t o r for t h e action of o t h e r constrictor agents, a n d m a y be the endogenous ligand at voltage-gated calcium channels. We have studied t h e effect of brachial a r t e r y infusion of E T (5pmol/min} on f o r e a r m blood flow (FBF) u s i n g s t r a i n g a u g e p l e t h y s m o g r a p h y , a n d of local i n f u s i o n on dorsal h a n d vein d i a m e t e r in n o r m a l volunteers. ET p r o d u c e d a slowly p r o g r e s s i v e r e d u c t i o n in F B F in t h e i n f u s e d arm, m a x i m a l a t 55 m i n (39 -+ 7%; n = 9). This was similar to t h e effect of e q u i m o l a r a n g i o t e n s i n (ANG) II (40 _+ 7%; n = 8) t h o u g h this was m a x i m a l at 5 min. The constriction w i t h ET was prolonged (T1/2 = 50min). The actions of both ET and ANG II were rapidly a n d similarly r e v e r s e d by co-infusion of nicardipine (10gg/min). The effect of h i g h e r doses of ET, given over s h o r t e r periods, suggest t h a t ET m a y be b i n d i n g i r r e v e r s i b l y to i t s r e c e p t o r . ET s i m i l a r l y p r o d u c e d a progressive reduction in h a n d vein d i a m e t e r over 60 m i n (53 _+12%; n=9), again with delayed offset, b u t here nicardipine, a t a dose (10gg/min) w h i c h abolishes K § - induced constriction, failed to reverse t h e effect. T h e s e c h a r a c t e r i s t i c s are unlike t h o s e of o t h e r constrictor agents, m a k i n g it unlikely t h a t t h e i r effects are m e d i a t e d by t h i s peptide. E T however, m a y have a n i m p o r t a n t role in l o n g - t e r m m o d u l a t i o n of p e r i p h e r a l r e s i s t a n c e a n d v e n o u s c a p a c i t a n c e in m a n . T h e failure of n i c a r d i p i n e to r e v e r s e t h e effect of E T i n v e i n s s u g g e s t s t h a t t h e m e c h a n i s m of action in t h e s e vessels m a y be i n d e p e n d e n t of voltage-gated calcium c h a n n e l s . D e p t . of P h a r m a c o l o g y a n d Clinical P h a r m a c o l o g y , St. George's Hospital Medical School, London SW17 ORE.

RECOMBINANT HUMAN ACIDIC FIBROBLAST GROWTH FACTOR INHIBITS INTIMAL HYPERPLASIA AFTER ENDOTHELIAL INJURY. Thorir D. Bjornsson, Maciej Dryjski, and Kenneth A. Thomas. Division of Clinical Pharmacology, Jefferson Medical College, Philadelphia, Pennsylvania, and Department of Biochemistry, Merck Sharp & Dohme Research Laboratories, Rahway, New Jersey, U.S.A.

OP 47.03

OP 47.05

POSITIVE INOTROPIC ACTION OF I~qlX3THELIN ON THE RAT CARDIAC MUSCLE. C. Y. Lee, M. J. Su and W. W. Lin Endothelin is a novel vasoconstrictor peptide, originally isolated from the culture medium of procine vascular endothelial cells. The present study was undertaken to examine the effect of synthetic endothelin on the rat cardiac muscle. In right atria, 3xi0 -8 M endothelin increased the force of contraction with less effect on the b e a t i n g rate. Higher concentrations of endothelin (10 -/ to 3xI0 -! M) caused a slight initial inhibitiion followed by an increase in the force of contraction and the resting tension with arrhythmogenic effect. This positive inotropic action was neither antagonized by organic calcium channel blockers nor inhibited by low calcium medium. Electrophysiological study on sinqle ventricular cells revealed that endothelin (I0-8-I0-7M) caused membrane depolarization end prolongation of action potential duration. Current clump study showed an increase of input resistance. Voltage clamp study indicated that the potassium current through the inward and delayed rectifiers were i~hibited. In addition, a prominent increase of peak sodium inward current end a slight decrease of calcium inward current by I0-7M endothelin were observed. These results suggest that the positive inotropism of endothelin may be mediated chiefly by a suppression of potassium outward current end partially b y a n increase of sodium inward current. Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwen, R.O.C.

DISPLACEMENT OF DIGITALIS GLYCOSIDES FROM THEIR RECEPTORS (Na.K-ATPase) IN HUMAN MYOCARDIAL ~ISSUE BY WASHOUT WITH DIGOXIN IMMUNE FAB (DIGIBIND~). Schmidt, T.A. and Kjeldsen, K. Department of Medicine B 2142, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark

The response to arterial endothelial cell injury is characterized by proliferation of smooth muscle cells (SMC) and accumulation of extracellular matrix (EM) in the intima to form intimal thickening, We have previously demonstrated that heparin and heparinoid are effective inhibitors of intimal hyperplasia in an endothelial injury model in the carotid artery in the rat U. Vasc. Surg., 8:623-633, 1988). We have now investigated the efficacy of human recombinant acidic fibreblast growth factor (r-aFGF) in this model. The injury was induced by a brief infusion of air into an isolated segment of the common carotid artery. This results in deendethelialization, followed by intimal SMC proliferation and EM accumulation, which reaches a maximum in two weeks, r-aFGF was administered by continuous i.v. infusion for two weeks at dosage rates ranging from 3 pg/kg/hr to 30 ng/kg/~, and as single i.v. doses of 0.5 and 5 gg/kg. Three to nine animals were in each group. The animals were sacrificed at two weeks and the carotid arteries fixed in situ for light and electron microscopy. The index of intimal thickening was the intima to media area (I/M) ratio. The control animals developed marked intimal thickening, with an I/M ratio of 0.97 + 0.13 (mean + SEM). After the i.v. infusions, there was a dose-related inhibition of infimal thickening, with 29%, 56%, 47% and 62% inhibition at 3, 30, 150 and 300 pg/kg/hr, reaching a maximum inhibition of 80% at 900 pg/kg/hr (I/M: 0.19 + 0.09). The highest infusion rates, 3 and 30 ng/kg/hr, were associated with 37% inhibition. The single i.v. doses, 0.5 and 5 ~tg/kg, were associated with 41% (I/M: 0.54 + 0.18) and 72% (I/M: 0.26 _+0.09) inhibition, respectively. Appropriate control studies were carried out with standard heparin, since r-aFGF was dissolved in a heparin-containing solution. It is concluded that r-aFGF has significant inhibitory effects on intimal thickening after endothelial injury, suggesting that it may have a value for the prevention of restenosis after vascular reconstructions.

During the last years a method using vanadate facili3 tated R-ouabain binding for complete quantification in biopsies or necropsies of human skeletal and myocardial digitalis glycoside (Na,K-ATPase) receptor concentration has been established. A problem has however been that in patients given digitalis glycosides 5-15% of the digitalis glycoside receptors ~eem to be occupied by digoxin prior to incubation in -H-ouabain. The present study was carried out to establish a method allowing the evaluation of whether this low figure in digitalized patients was due to a simple occupation of receptors by digitalis glycosides, or whether there was a downregulation, no regulation or even an upregulation of receptor concentration during digitalization. To remove digitalis glycosides a washout of muscle samples was performed. When washing for 16 o . houri at 37 C in buffer containing 500 pmol/ml Digibind~ the half-time (T~) for loss of specifically bound digitalis glycosideswas 1,5 hours, whereas th~s value was 2 8 hours without the addition of Digibind-. On thzs basis a washout for 16 ~ours at 37 C mn buffer containing 500 pmol/ml Digibind~ was used for further studies. It was found that an occupancy of heart digitalis glycoside receptors of ~round 20 pmol/g wet weight obtained by incubation in VH-digbxin in vitro of myocardial necropsies from undigitallzed subjects, was reduced to around 0,5 pmol/g wet wt. after this ~ashout. Furthermore, it was found that rebinding with H-ouabain after this washout gave values as if no prior exposure to digitalis glycosides and Digibind R had taken place (around 400 pmol/g wet wt.). We propose washout at 37~ in Digibind for 15 h before $H-ouabain binding.

A 117

OP 47.06 Withdrawn

OP 48.02 THE EFFECT OF METOCLOPRAWIDE AND CISAPRIDE ON THE PHARMACOKINETICS OF PHENPROCOUMON H.M~n• and H.D. Bruhn The possible interactions (as suggested by,clinical observations) between phenprocoumon (P,Mercumar) and either metoclopramide (~I) or cisapride (C) have been evaluated in sn open cross-~ver trial. P (0.22 mgxkg-') was given to 24 healthy volunteers alone or together with either ~ [3xi0 mg/o over 10 days) or G (4xi0 mg/d over 10 days) as a single oral dose on day 4 of ~I or C administration.Plasma samples for the HPLC measurement of P concentrations were taken at certain intervals up to ? days and pharmacokinetic parameters were calculateO. Coedministration of M decreased the AUCo-oo of P from 287 • 51 to 241 ~ 61 mgxhxl- (p -- 0.05) with e corresponding decrease of half-life from 132 + 31 to 111 + 16 h [p -- O.05).Furthermore,mean transit tim; (MTT) of P-was reduced from 18~ + 44 to 181 + 23 h when M was coadministered (p _"O.05).These--parameters remained unaffectap w h ~ C was given (AUCo-oo: 324 + 100 and 297 + 94 mgxhxl ,resp.,half-life: 132 ~ 28 ~nd 138 + 25 hTresp.; MTT: 187 § 36 and 195 + 35 h,resp.).Peak concentrations [Cmax) were not affected by either of the drugs,whereas e decreased time to peak [Tmex) from 2.8 ~ 1.5 to 1.6 0.9 h was observed w~en C was coadministersd.However, this effect did not reach statistical significance. Although in contrast to M the effect of C on AUC did not reach statistical significance a similar tendency was observed concerning a reduction of AUC after administration of P. In keeping with these findings we observed in a few cases that during treatment with C th@ AUC of P was clearly re~uced, We c o n c l u d e t h a t C and M s h o u l d be used w i t h c a u t i o n i n c o m b i n a t i o n w i t h P.

1.Med. Klinik der Christian-Albrechts-UniversitEt, Schittenhelmstr.12,D-2300 Kiel,end ~danssen Research Foundetian,Raiffeisenstr.8,D-4040 Neuss 21

OP 48.01

OP 48.03

L A C K OF E F F E C T OF A N T I P Y R E T I C S O N THE P H A R M A C O K I N E T I C S OF C H L O R O Q U I N E

EFFECT OF MISOPROSTOL (MISO) ON CYCLOSPORINE (CSA) BLOOD LEVELS IN RENAL TRANSPLANT (TX) PATIENTS. Maddux, S Veremis, SM Moran, C Bartkus, R Pollak,M Mozes Prostaglandins (PG) markedly decrease CSA bioavailability in the rat (Clin Nephrol 1986;25(Suppl I):$95). However, the effects of PG on CSA kinetics in humans has not been studied. We conducted a randomized, double-blind, controlled trial of PG in CSA-treated renal TX patients. The purpose was to study the effects of MISO (a PGEI analogue) on post-TX renal function. Results of renal function studies are reported elsewhere. We report here the effects of MISO on CSA levels (RIA and HPLC). Subjects received pc MISO 200ug or placebo QID beginning with the first CSA dose pre-TX and continuing for 12 weeks poat-TX. The same po CSA dosing protocol was used in the MISO and placebo groups, beginning at 14mg/Eg/d and tapering to 7mg/Kg/d by 12 weeks. Drugs known to interact with CSA were avoide& Trough CSA levels were measured serially. Of the 77 patients enrolled, 65 were evaluable (32 MISO/33 placebo). The 2 groups did not differ in age, sex, race, prednisone dose, antimierobial use or serial post-TX labs (liver enzymes, bill, hematocrit). Mean trough CSA blood levels (+SD) in each study group are tabulated below: HPLC* RIA* Week** MI80 PLACEBO MISO----- PLACEBO 1 279+201 231+155 480+271 552+341 2 1765114 1305117 4225288 3715190 3 1915182 110570 4335223 3885158 4 1567117 98548 4545238 4035179 8 114570 104562 4105280 3565156 12 104570 114563 2875136 3085147 16# 87547 85543 2425157 1975106 * ng/ml. Differences ~MISO v. PLACEBO) not signif (p>.05). **CSA dose (mg/Kg/d) not different during any week (p>.05). # Four weeks after discontinuation of study drug. We conclude that MISO has no significant effect on CSA trough blood levels in renal TX recipients. University of Illinois at Chicago, 833 S. Wood Street, Room 244, Chicago, IL 60612 USA

R.K.Raina

and V . K a p o o r .

The p r e s e n t p a p e r r e p o r t s the e f f e c t of a n t i p y r e t i c s ; a s p i r i n , p a r a c e t a m o l and a n a l g i n on the p h a r m a c o k i n e t i c s o f c h l o r o q u i n e . E i g h t male h e a l t h y s u b j e c t s (21-24 y r , 5 4 - 6 5 Kg) w i t h n o r m a l h a e m m a t o l o g i c a l and b i o c h e m i c a l v a l u e s ( i n c l u d i n g l i v e r and k i d n e y f u n c t i o n tests) w h o w e r e n o n s m o k e r s and a b s t a i n e d f r o m alcohol r e c e i v e d on s e p a r a t e o c c a s i o n s (with w a s h o u t p e r i o d of one week) a s i n g l e oral d o s e of c h l o r o q u i n e (750 mg) a l o n e or in c o m b i n a t i o n w i t h e i t h e r a s p i r i n (325 m g ) , p a r a c e t a m o l or a n a l g i n (each 500 m g ) . C h l o r o q u i n e was e s t i m a t e d f l u o r i m e t r i c a l l y ( A d e l u s i , S A and S a l a k o , L A ; J . P h a r m . P h a r m a c 3 2 : 7 1 1 , 1 9 8 0 ) in serial v e n o u s b l o o d s a m p l e s c o l l e c t e d u p t o 120 h a f t e r d r u g a d m i n i s t r a t i o n . P h a r m a c o k i n e t i c p a r a m e t e r s of c h l o r o q u i n e w e r e a d e q u a t e S y d e s c r i b e d b y a two c o m p a r t m e n t model and r e v e a l e d a r a p i d p h a s e of a b s o r p t i o n w i t h a C of 6 7 . 7 + 2 . 6 5 n g / m l a t t a i n e d w i t h in 5 . 6 - i ~ h . The b i p h a ~ i c d e c a y c u r v e had o n , v a l u e of 0 . 0 5 + 0 . 0 0 2 h- and a t e r m i n a l h a l f l i f e (t~ 5 ) of 1 6 1 . 6 7 i 1 5 . 2 h , C o a d m i n i s t r a t i o n of t h ~ ' a n t i p y r e t i c s d i d not s i g n i f i c a n t l y a l t e r p h a r m a c o k i n e t i c p r o f i l e of c h l o r o q u i n e e x c e p t an e n h a n c e d C of the antimalarial with paracetamol (7~+3.2 ng/ml) and a n a l g i n ( 8 2 . 0 i 3 . 3 n g / m l ) . A c c o r d i n g l y a s p i r i n , p a r a e e t a m o l or a n a l g i n c o a d m i n i s t r a t ion w i t h c h l o r o q u i n e is l i k e l y to be of l i t t l e s i g n i f i c a n c e in the c l i n i c a l use of the l a t t e r drug. D e p a r t m e n t of P h a r m a c o l o g y & T h e r a p e u t i c s , G o v e r n m e n t M e d i c a l C o l l e g e ~ J a m m u (Tawi) 180001, India.

A 118

OP 48.04

OP 48.06

ANTAGONISM OF CAFFEINE-INDUCED INSOMNIA (300 MG) BY ZOLPIDEM (20MG) IN HEALTHY VOLUNTEERS P. Rosenzweig, S. Trocherie, B. Vandel,~S. Vandel~ Ph. Danjouj and P.L. Morselli. The effects of a new imidazopyridazine, zolpidem, were assessed in a model of chemically-induced insomnia. 8 healthy volunteers (4 males, 4 females) were included in a double-blind, randomized placebo-controlled, latin square design trial. All the subjects (mean age 25.1 • i.i years, mean weight 62.1 • 3.3 Kg) were free of sleep disorders. Subjects received single doses of placebo (PL), caffeine (CAF) 300 mg, zolpidem (ZOL)20 mg and both (ZOL + CAF) at one week intervals. Caffeine was given at 9:30 PM 45 minutes before zolpidem. A double placebo was used. The sleep status was assessed by a trained rater using a Stanford Sleeping Scale (SSS) at the time of zolpidem intake and i, 2, 3, 4, 6, 8 and 9 hours after. Self-evaluation of sleep parameters was performed, using visual analog scales. A global cemparison with a normal night was also used as an integrating parameter. Ratings of SSS showed that the hypnotic effect of zelpidem 1 and 2 hours after intake, was unaffected by caffeine, (one hour post zolpidem : P = 2.1 • 0.7, ZOL = 4.1 • 0.6, CAF = 2.5 • 06, ZOL + CAF = 3.3 • 0.6) (two hours P = 5.4 i 1.0, ZOL 6.5 • 0.4, CAF = 4.5 • 0.7, Z0L + CAF = 6.A • 0.5). Zolpidem antagonized most of the deleterious effects of caffeine on the subjective assessment of sleep latency, "ease to fall asleep", as well as the subjective effects of caffeine-induced insomnia, (assessed item by item), and improved the quality of sleep compared with CAF alone. However, when the global feelings of the subjects were analyzed, the night "ZOL+CAF" was not as good as the night "ZOL", confirming the antagonistic actions of the two compounds. Centre de Recherche du Service de Sant4 des Arm4es 24, ave du Maquis du Gr4sivaudan 38700 La Trenche France

THE USE OF THE JACKNIFE TECHNIQUE TO ESTIMATE ERROR IN AUC DETERMINATION AND STUDY DESIGN OPTIMIZATION P.A. Milli~an~ A.W. Kelman, B_m.Whitin ~ Bioequivalence can be accepted when the difference between two AUC determinations is <20%, Arriving at this conclusion, however, depends partly on quantitating the errors in the respective AUCs. This information is required if the Power of the study to detect the critical difference of (and therefore the number of subjects required) is to be determined. We propose that these errors can be determined by the Jacknife technique, which allows estimation of the error in any data set by sequential removal and replacement of single data points. We intend to study the influence of cimetidine and nizatidine on the steady state AUC of piroxicam. Comparisons would be made of the A U C o _ T of the NSAID alone, and in combination with an H2-antagonist. In a preliminary piroxicam kinetic s t u d y 6 male volunteers each received a single 20 mg oral dose and frequent venous blood samples (40 x 5 ml) were taken for 6 days. The data were fitted to a 1 compartment model with Ist order abso~T.tion and elimination. The average residual error was 11.5 + 2.4%. Thirty simulations were then performed with 3 se~s of parameters based on values obtained from the single dose study. A sampling schedule appropriate for the steady state interaction study was employed, with random error set at 15%. The mean % Jacknife errors for each parameter set were (a) average parameters, 6.26; (b) upper extreme parameters, 6.62 and (c) lower extreme parameters, 5.97. In the context of a comparison of two AUCs, this Jacknife error results in 10% uncertainty in the ratio of AUCs. 15 patients would provide a Power of >99% to detect a 20% difference in the steady-state AUCs. This technique therefore can contribute to optimum experimental design and can ensure that comparative area studies are carried out under rigorous statistical conditions. Department of Materia Medica, Stobhill General Hospital, Glasgow, G21 3UW, Scotland.

OP 48.05

OP 49.01

PYRAZINAMIDE INTERACTION WITH SOME ANTI TUBERCULOSIS DRUGS - A STUDY. ** D.P.Varshney~ M.K.Varshney, K.C.Singhal& H.Kumar Pyrazinamide is t h e p r e f e r r e d d r u g u s e d in c o m b • for the treatment of T u b e r c u l o s i s . T h i r ty p a t i e n t s of P u l m o n a r y Tuberculosis having hepatic and renal functions within normal limits were selected for the study. They were divided i n t o 3 g r o u p s of i0 p a t i e n t s each.Group A,B & C were administered Isoniazid,Ethambutol & Rifampicin orally respectively in s t a n d a r d d o s e s a n d o n d a y 7 t h e s e r u m l e v e l s of t h e r e s p e c t i v e drug ( 2 , 4 , 6 & 24 hrs) a n d u r i n a r y e l i m i n a t i o n (2,4,6 & 24 hrs) i n c l u d i n g other pharmacokinetic parameters were determined.From the 8th day onwards Pyrazinamide (25mg/Kg) was simultaneously admini s t e r e d to a l l p a t i e n t s in e a c h g r o u p a n d o n d a y 7 parameters for the respective d r u g in e a c h group were repeated.In group A simultaneously administration of PZ r e s u l t e d in l o w e r i n g t h e s e r u m l e v e l s of I N H s i g n i f i c a n t l y Cmax(3.76 • 0.53 from 4.34 • 0,44~Lig/ml)observed at t h e e n d o f 2 h r s (Tmax) a l t h o u g h t 89 a n d T m a x w e r e n o t significantly affected, Kel, Vd &Clp increased significantly while AUC decreased significantly. PZ ~ i g n i f i c a n t l y affected the serum INH levels, r e d u c i n g m o r e in s l o w a c e t y l a t o r s as c o m p a r e d to r a p i d o n e s ; its l e v e l s h o w e v e r r e m a i n e d a b o v e the minimum therapeutic levels. In group B & C simultaneous administration o f PZ d i d n o t s i g n i ficantly interact with the pharmacokinetics of E T H a n d RMP. * S e c t i o n of T u b e r c u l o s i s & Chest Diseases and **Department of M i c r o b i o l o g y , J.N.Medical College, A . M . U , A l i g a r h - 202 002. ( I N D I A ) .

EXERCISE INDUCED ALTERATIONS ON PHARMACOKINETICS OF PROPRANOLOL S. M. Somani, S Frank and M Kohnle This study examines the e f f e c t of submaximal exercise on the pharmacokinetics of propranolol (P) in man. 15 healthy male volunteers had an eight hour sedentary study in a post absorptive state. P, I mg, was administered intravenously and blood was drawn at 2, 5, I0, 15, 30, and 90 min. and at 2, 4, 6 and 8 hours. A f t e r 17 days the same 15 subjects were administered P ( I mg IV) and immediately exercised f o r 20 min every hr f o r 8 hr at 60% of V% max. Blood was drawn at the same times. P was determined in plasma by HPLC using fluorescence detector . Pharmacokinetic parameters were obtained by using JANA Program. There was a wide individual v a r i a t i o n in the pharmacokinetics f o r each volunteer and a large d i f f e r e n c e in the degree of changes with exercise. Two groups with opposite e f f e c t s were i d e n t i f i e d . One group (9 volunteers) had an i~crease in (AUC)with exercise from 467 to 753 ng ml - min (p = 0.005) and a marked d~creas~ in clearance from 34.3 to 19.7 ml min kg (p = 0.004). The second group (5 volunteer~) had a decrease in AUC from 727 to 425 ng ml- min (p : 0.017) ~nd a~ increase in clearance from 18.9 to 34.7 ml min kg (p = 0.037). There was a s l i g h t decrease in K~ with exercise in group I and no change in KR in group I I . The e f f e c t of exercise on prop~anolol pharmacokinetics is marked but v a r i a b l e . Exercise increases cardiac ouput but d i v e r t s blood flow away from the l i v e r and could decrease clearance of drugs, p a r t i c u l a r l y those which are hepatic e x t r a c t a b l e such as propranolol. This phenomenon may have profound e f f e c t s on patients taking the drug on a chronic basis who exercise i r r e g u l a r l y and drug doses may have to be adjusted. Department of Pharmacology and Medicine, Southern I l l i n o i s U n i v e r s i t y , School of Medicine, S p r i n g f i e l d , l l l i n o i s , U.S.A. 62794-9230

A 119

OP 49.02

OP 49.04

COMPARISON OF SOTALOL, BISOPROLOL AND PROPRANOLOL PHARMACOKINETICS IN OBESE SUBJECTS. G. CHEYMOL, J.M. POIRIER, C. LE JEUNNE, O. ERTZBISCHOFF, J. BARR{. Pathophysiological changes due to obesity may modify pharmacokinetics of lipophilic substances. Beta-blockers are used in disease states in which obesity is a risk factor. We compared in obese (120 to 164% of ideal weight : IBW) and normal subjects (85 to 103% of IBW), the pharmacokinetics of single i.v. administration of beta-blockers with different solubilities : d,l-sotalol markedly hydrpphilic (1.07mgof base.kg-1 IBW), d,l-propranolol highly lipophilic (0.11mg of base.kg-11BW), and d,l-bisoprolol of intermediate solu bility (0.16mgof base.kg-1 IBW). Protein binding of propranolol did not differ between obese and control groups (mZS.D. : 86.6~ 1.8%vs 88.3 + 1,6% respectively). In obese subjects the pharma~okinetie data (m+S.D.) calcu lated for sotalol (total clearance : C L = 9 . 4 + 2 . 9 l.h-1 ; volume of distribution : V~= 0.9+0.21.kg-I of body weight; terminal half-life : tl/2~=6.2_+~6h) were comparable with those measured in the controls ( C L = 7 . 0 + 2.2 l.h-1 ; V~= 1.1 +0.1 l.kg-1 ; tI/2~ = 7 . 3 + 1.1 h). For bisoprolol the range ~f data did not show a clear difference between obese and controls subjects : CL= 13.0- 17.2vs 11.3- 14.91.h-I respec tively ; V~= 1.6-2.2vs 2.1- 2.91.kg-I ; tI/2~ = 6 . 4 - 8 . 6 vs 6.3- 7.6h). As concerned propranolol CL (44.~ !15.9 l.h-1) and V~ (2.7!0.7 l.kg-1) were significantly lower thanval~s in the control subjects (CL= 75.9+ 15.41.h-I ;V~=5.1 !1"3 l.kg-1), tl/2~did not differ (3.95 1.1hvs3.1 !0"9h)" These results show no clear relationship between liposolu bility of beta-blockers and tissue distribution in theobes~ Others factors may intervene in drugs diffusion. Perhaps altered blood flow in adipose tissue in obese subjects could explain decrease of V~ of propranolol. Altered hepatic function is proposed to explain the decrea se of clearance of propranolol.

CIRCADIAN RHYTkT~ OF SERL~4 SULFATE LEVEI~ IN MAN AND ACETAMINOPHEN CHRONOPHARMACOKINETICS R.K. Verbeeck, D.A. Hoffman and S.M. Wallace A circadian rhythm in serum sulfate (SUL) levels has been previously reported in man. Sulfoconjugation of acetaminophen (AP) is affected by the availability of inorganic sulfate (co-substrate) and therefore may follow a circadian r h y t ~ in seru~n SUL levels. Serum and urine SUL concentrations were measured by HPLC (ion chromatography, conductivity detection) in 7 young men during a 24 h period. Serum SUL levels peaked (407.8_+42.7 ~M) on average at 7 pm (range: 3 pm to ii pro) and reached a min/mu~ (302.3_+40.2 ~M) at ii am (range: 7 am to 3 pro). The pharmacokinetics of AP were studied in the same subject during 2 consecutive dosing intervals (8 am-2 ,pm, 2 l~n-8 pm) on Day 4 of a 650 mg AP q.i.d, dosing regimen. Serum and urine concentrations of AP, its sulfate (APS) and glucuronide (APG) conjugates were measured by HPLC. Subchronic AP administration resulted in a 28.3% decrease in serum SUL levels: the mean levels were 352.3_+35.4 ~M (control) vs 252.5+18.9 ~ (AP study). The difference between minimum and maximum serum,,SUL concentratior~s was slightly larger during AP administration: 31.3_+5.1% vs 20.5_+8.5% (control). Renal SUL clearance decreased (p<0.05) during AP administration: 0.58_+0.11 (control) vs 0.39_+0.10 ml/min/kg (AP study). No difference in AP clearance or in APS and APG formation clearances was found between the am and pm dosing intervals. Also, urinary recoveries of AP, APS and APG were not affected by t/%e time of administration. In conclusion, (i) subchronic AP administration lowers serum SDL levels without abolishing the circadian variation, (2) lower seru~ SUL levels reduce renal SUL clearance, (3) fluctuations in sertml SUL levels between the am and pm AP dosing intervals did not affect sulfoconjugation of AP. College of Pharmacy, University of Saskatchewan, Saskatcon, Sask S7N 0W0, CANADA.

Service de Pharmacologie, HSpital St Antoine, 184 Rue du Fbg St Antoine, 75012 PARIS. FRANCE

OP 49.03

OP 49.05

ETHNIC DIFFERENCE IN THE DISPOSITION OF NITROGLYCERIN AND ITS METABOLITES FOLLOWING A SINGLE DOSE APPLICATION OF TRANSDERMAL NITROGLYCERIN K.M.Thakker, V.A.John, C.Cabet, L.Z.Benet, E.T.Lin and R.L.Williams There is a paucity of published studies doetu~enting ethnic differences in the disposition of drugs from transdermal therapeutic systems. This possibility was restrospectively evaluated upon completion of a bioequivalency study comparing two different Nitroglycerin transdermal products. Two patches each (Total Dose = 10mg Nitroglycerin) of Transderm Nitro (Smg released/24 hours, CIBA) and NTS (5mg released/24 hours, BOLAR) were applied to 16 healthy volunteers in a randomized open label crossover study. The ethnic groups represented were Caueasians(N=ll), Blacks (N=4) and Asian (N=I). Blood samples were collected at appropriate times post early morning patch application and plasma analyzed for nitroglycerin(NTG),l,2 glyeeryl dinitrate (1,2 DNG) and 1,3 glyceryl dinitrate(l,3 DNG) using a sensitive, specific GC assay. The population mean plasma concentration-time profiles as well as model independent bioavailability parameters (CPEAK,TPEAK, AUC(0-12) and AUC(0-24)) were estimated and analyzed using the usual statistical tests. Plasma profiles were qualitatively similar in both ethnic populations. However, quantitative analysis revealed that there was a distinctly lower NTG and metabolites plasma-concentration time profile, on average, for Blacks compared to Caucasians. The observed statistical trend in their bioavailability parameters corroborated these ethnic differences. The nearly 100k ethnic difference observed in NTG. 1,2 DNG and 1,3 DNG kinetics were independent of the particular patch system applied and warrant further evaluation in a prospective clinical trial in the diseased ethnic population. Ciba-Geigy Pharmaceuticals Division,Clinical Pharmacokinetics and Disposition Department, 444 Saw Mill River Road, Ardsley, New York 10502.

DISPOSITION OF PROPOFOL IN PREGNANT WOMEN UNDERGOING ELECTIVE CAESAREAN SECTION K. Chan I, M.A. Gregory 2, T. Buckley 2, T. Gin 2 and T.E.

Propofol, the newest intravenous anaesthetic, has been used for both induction and maintenance of general anaesthesia with predictability and rapid action and recovery. Pharmacokinetics of the drug have been studied in patients undergoing various surgical procedures. However, no information is available on the kinetics of propofol in obstetric patients. The disposition of propofol was studied with ethical approval in i0 healthy Chinese women {Age 25 to 34 yrs; weight 55 to 82 kg and height 146 to 163 cm) who underwent caesarean section. General anaesthesia was induced, after a three minute period of pre-oxygenation, with propofol 2.0 mg/kg over a period of 20 sec into a fast running drip. Anaesthesia was maintained with 1.0% enflurane and 50% Ol in N20, while other medications used included suxamethonlum (1.5 mg/kg) and atracurium (0.3 mg/kg). Blood samples were taken at 0, 2.5, 5, 10, 20, 30, 60, 120, 240, 360, 480 and 720 min. Propofol in whole blood was assayed by liquid chromatography with fluorometric detection. The blood concentrations of propofol decreased rapidly from 2.5 min to 20 min and then declinely more slowly and could be detected up to 8 h. The mean (• S.D.) termination elimination t~, total blood clearance, volume of distribution (Vss), ana ~ean residence time were 81.3 • 18.9 min, 2.6 • 0.5 L min- , 173.2 • 41.6 L, and 69.2 • 17.9 min respectively. The terminal elimination t~ was shorter and total clearance greater than reported values on non-pre@nant surgical women (284 • 40 min and 1.9 • 0.4 L min -~ respectively).. Departments of Pharmacology1 and Anaesthesia & Intensive Care = , The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.

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OP 49.06 TISSUE DETECTION OF THE QUINOLONEANTIBIOTIC FLEROXACIN IN HUMAN VOLUNTEERSBY 19-F NMR SPECTROSCOPY p Jynge; T Skjetne, I Gribbestad, 0 Antonsen, J Krane, OE Bakoy, KM Furuheim, OG Nilsen, CH Kleinbloesem. Fluorine (19-F) NMR spectroscopy (MRS) was used for in v i t r o characterization (at 11.7 T) of the quinolone a n t i b i o t i c Fleroxacin (ROCHE) containing 3 f l u o r i n e atoms. Thereafter 19-F MRS was applied for in vivo detection of Fleroxacin in l i v e r and skeletal (calf) muscle of healthy human volunteers (n=5). In vivo examinations were performed i n t e r m i t t e n t l y (over a 24 hour period a f t e r oral drug intake) using a Philips Gyroscan S15 instrument (1.5T) for imaging (MRI) and MRS. Blood samples were withdrawn for plasma concentration measurements by HPLC. In v i t r o MRS revealed binding or interaction effects to serum and rat tissue and the spectral overlap of parent substance and metabolites. In vivo spectra of Fleroxacin/ metabolites were obtained from both l i v e r and muscle with maximum peaks a f t e r respectively I-2 and 5-6 hours. Elimination t89 was about 14 and 11 hours for respectively plasma and l i v e r and probably longer in muscle. By combining results from in vivo MRI/MRS and MRS of phantoms approximate mean C-max values were calculated to respect i v e l y about 240 and 60 umole/l for l i v e r and muscle. The signal to noise r a t i o of the in vivo MRS spectra was rather low and the present data should be regarded as preliminary. The results indicate, however, that Fleroxacin is well d i s t r i b u t e d to human l i v e r and muscle, and that 19-F MRS may have a future potential in the study of tissue pharmacokinetics.

Dept. of Pharmacologyand Toxicology, Faculty of Medicine, Univ. of Trondheim. Center for Nuclear Magnetic Resonance, SINTEF/Univ. of Trondheim, Trondheim, Norway. F. HoffmannLa Roche, Basel, Switzerland.

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Poster Presentations

PP 01.01

PP 01.02

MEFLOQUINE FOLLOW SAFE, WELL TOLERATED AND HIGH E F F E C T I V E IN T H E T R E A T M E N T OF MULTIDRUG RESISTANT FALCIPARUM MALARIA IN B R A Z I L . J . M D E S O U Z A , R.H. L E I M E R A N D R.F. B R A U N

THE DISPOSITION OF QUININE AND QUINIDINE IN THE INFECTED ISOLATED PERFUSED RAT LIVER - A MODEL OF CLINICAL MAIARIA IS.M. Mansor, 2S.A. Ward, 1,2G. Edwards, Ip.E. Hoaksey and IA.M. Breckenridge Although there is clinical and pathological evidence of hepatic damage and changes in ultrastructure are associated with malaria infection (MI) the role of liver impairment in the pharmacoklnetlc changes of quinine (QN) and qulnidlne (QD) observed during malaria (White, N.J., Eur. J. Clin. Pharmacol, 34, I, 1988) is unclear. Since QN and QD are cleared predominantly by hepatic metabolism and are low to intermediate clearance drugs, it might be expected that hepatic clearance will be affected by changes in hepatic enzyme activity produced by MI. We have studied the effect of malaria on the disposition of QN and QD in the livers isolated from rats infected with merozoites of P. berghei~ a rodent model of clinical malaria (N=5), and non-infected controls (N=5). Following bolus administration of QN (ling) or QD (ling) to the I00 m/ recycling perfusion circuit, perfusate was sampled (0-4hr) and plasma assayed for QN and QD by HPLC. Statistical comparisons were by Student 't' test accepting significance when P 9 0.05. Higher QN (AUC: 6470 + ii01 vs 3822 + 347 ng hr/ml, P 9 0.001) and QD (AUC: 6642 + 1304 vs 4808 + 872, P 9 0.05) concentrations were observed during MI. MI resulted in decreased QN clearance [CI] (0.33 _+ 0.08 vs 0.64 + 0.09 ml/min/g, P 9 0.001) and volume of distribution [Vd] (53 + 13.3 vs 81.2 + 23.7, P < 0.05) with a trend towards a longer elimination half-life [T89 (1.93 + 0.6 vs 1.37 + 0.25 hr, P > 0.05). However with QD, MI resulted in decreased CI (0.38 + 0.16 vs 0.64 +_ 0.09, P 9 with no change in Vd and a significant increase in T~ (1.62 + 0.42 vs 0.88 + 0.22, P 9 0.01). The hepatic disposition of QN and QD is altered during MI and emphasises the need for a proper understanding of the clinical pharmacokinetics of drugs in disease states before therapeutic regimens are devised. IDepartment of Pharmacology and Therapeutics, [hiversity of Liverpool, P.O. Box 147, Liverpool L69 3BX. 2Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA.

After performed the inpatient studies with mefloquine and mefloquine combination (MSP) in o u r Contry was decided by Brazilian Health Ministry t h e u s e o f m e f l o q u i n e in o u t p a t i e n t s working in areas of high transmission (Garimpos) where are very common the presence of multi-drug resistant falciparum malaria c a s e s as p a r t o f a c a m p a i g n for help the malaria control. T h e f i r s t u s e of the synthetic quinolinomethanol in t h e f i e l d o c c u r r e d in D e c e m b e r 1986 with results apparently satisfaetories in s p i t e t h e g r e a t d i f f i c u t i e s to obtain a good follow-up for all cases treated. In 1987 was decided by SUCAM's malaria b r a n c h to start a programme of monitoring the P.falciparum response to t h e d r u g s in A m a z o n R e g i o n . A t t h e m o m e n t w e c a n s h o w t h e r e s u l t s o f 213 o u t p a t i e n t s t r e a t e d in B e l e m , G o i a n i a , Itaituba and Maraba. One third of the c a s e s w e r e f o l l o w e d f o r 63 d a y s a n d t h e o t h e r 144 f o r 35 d a y s . A l l c a s e s had received previous treatment w i t h o n e or more drugs without good results. No toxicity occurred in a n y c a s e . T h e s i d e e f f e c t s w e r e m i l d a n d transient a n d no r e q u i r e d special treatment. Dizziness, nauseaBnd diarrhoea were the most important complaint. Small number of cases with gametocytes a p p e a r e d b u t u s u a l l y a t d a y 21 t h e sexual forms were absent. The clearance of the assexual parasites o c c u r r e d b y d a y 4 in m o r e t h a n 90% o f t h e p a t i e n t s . A s m e f l o q u i n e remain indeed effective in t h e c u r e of r e s i s t a n t falciparum malaria S U C A M d e c i d e d to u s e t h i s d r u g as t h e f i r s t c h o i c e in t h e a r e a s f r e e o f t r a n s m i s s i o n . NPRH U F P A - B e l ~ m , B r a z i l / F. H O F F M A N N - L A R O C H E BASLE, Switzerland / SUCAM- DR-PA, Bel~m, Brazil -

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PP 01.03

PP 01.05

ON THE QUESTION OF THE OPTIMAL P~RENTERAL ROUTE OF OHLOROQUINE ADMINISTRATION i~ SEVEVd~ MALAEIA O. Walker and L.A. Salako There have been cases of accidental death following the ~arenteral administration of chloroqulne. Two such death occtu'red in our hospital recently after the administration of 5 mg/kg i.m. of chloroquine base in children. To answer the question of the optimal parenteral route of administration in severe malaria, the single-dose kinetics of 2.5 mg/kg chloroquine base was investigated after, slow i.v. infusion (over 30 min) and I.M. and S.C. injections in healthy volunteers. Methods: 22 subjects volunteered for the studies. Venous blood, (10 ml) was taken at the following scheduled times; O, 0.25, 0.5, 1, 2, h, 8, 2h h, and then, on days 3, 5, 7, 1~, 21, 28 and 35- ~lood pressure and heart rate were monitored every 15 min in the immediate 2 h following administration of the drug. Chloroquine and its main metabolite, desethylchloroquine were analysed in duplicates using hplc. Results Vd Clp CIR Cm~x

Comparative i~ vitro sensitivity of P. falcioarum to chloroquine, mefloquine and quinine in Zaria~ Northern ~igeria. L.Lege-Oguntoye~ J.U. Abua~ B. Werblinska~ ~.N. Ogala, A. Slotboom~ P,F. Olurinola

~oute (n,dmI,) Tma~(h) ~(h) ,,(~/~) ,(~l/~in>,,(~) l.V.

249•

I.M.

537+190

15 min

250-+62

261 •

66h t320

3h6 •

12. I

217Z94

181 •

657 •

145 •

168+50

172

79b

• S.C.

297+128

25+8

Isolates of P. falciparum were obtained from 6 months to 6 years old children w i t h clinical malaria~ resident in Zaria urban area. The comparative in vitro sensitivities of the parasites to chloroquine, mefloquine and quinine in the area were assessed by use of the WHO standard micro-test. For 14 (36.8%) of 38 isolates.schizont maturation was observed at a chloroquine'concentration of 1.6 x 10'6 mol/L blood and for I (7.2%)i of 14 isolates at a quinine concentration of 52.8 x 10-6 mol/L. For mefloquine, all of 38 isolates tested exhibited schizont maturation at a drug concentration of 0.8 x 10-6 mol/L and I0 (26.3%) at 3.2 x 10 -6 mol/ L. These results indicate that 37% of P, falciparum isolates from the study area are resistant to chloroquins in vitro and 7% to quinine, while the in vitro sensitivity to meflequine is markedly reduced.

Disoussi0n The results show that when chloroquine is given both by S.C. and I.M. routes, the drug is rapidly absorbed, and peak concentrations that may result in toxic adversedrug reaction are rapidly reached. On the other hand, d~ta from the slow ~ntravenous infusion suggests t ~ t the peak concentrations obtained depend on the rate of infusion. This proves that this route is superior to others under controlled conditions. Dept. of Pharmacology, C611ege 9f Medicine. I h ~ n , Nigeria

PP 01.04

PP 01.06

PRELIMINARY RESULTS QF INVEsTIGATIONs ON THE COMPARATIVE IN VIVO/IN VITRO SENSITIVITY OF P.F~LCI~ PARUM TO SULP~LADOXINE-PYRI~THAMINE (FANSIDAR) IN ZARIA, NORTHERN NIGERIA S.I. Adagu. L. Lege-Oguntoye, B. Werblinska. W.N. Ogala, A. Slotboom

P ~ CONCENTRATIONS OF CHLOEOQUINE AND ITS N~TABOLITE AFTER ORAL ADMINISTRATION IN UNCOMPLICATED MALARIA K W e e r a s u r i ~ . MPD Mahindamatne. PLD~ Perera. DTU

The WHO Extended Field Test was applied to assess the in vivo sensitivity of P. falciparum to sulphadoxine-pyrimethamine (SDX/PyR) in 19 children w i t h clinical malaria aged 6 months to 6 years. Of these, 7 (37%) were found to be resistant to the drug at the RI/RII level. The remaining 12 children became aparasltaemic before day 7 a~d the Mean Parasite Clearance Time calculated for these was 4.0 days. in all the 19 children, parasite density on day 2 ~as less than 25% of that found on day O. 6 (31%) of 19 P. falcigarum isolates were successfully gro~n in vitro using the WKO standard micro-test. For all 6 isolates schizont ~aturati0~ occurred in the oresence SDX i0000~ om01/PYR 125 pmol per well,~i,e, sDX 2000 x 10-mol/~yR 25 x 10-6 mol per litre blood, indicating in vitro resistance. The 6 isolates xouna resistant to sDX/PYR i n vitro had also exhibited resistance in vivo except in the case of one malnourished child where delayed parasite clearance was seen on day 6.

Wi.~era%ne & LMV Tilleker~%ne Twelve ~b~lant patients (IIM IF) With uncomplicated malaria (i0 vivax. 2 f~icipartln) were studied afteP inform~ consent. Chloroquine (CQ) was Eiven as ~. a and 2 tabs at 0900h on consecutive days (i unseated tablet = 150m4~ of OQ base). Blood samples were collected through an indwellin~ cannula at 0 2 a 6 8 12 2~ (predose) 26 2S 30 32 36 h8 (predose) 50 52 5a 56 60 and 72 hours into plastic lithium hepa~In tubes. Plasma was s e p ~ t e d immediately by high speed centrifu~ation and stored at -20 C until anal~sis. Plasma CQ and its me•177 (Deseth~ichloroqulne DEQ) were assayed with a HPLC (UV de%ester) With a ~odifioation of a previous ~ % h o d (G. Alvan, J. ~ t . 229. 2al, 1982). Ten patients were neEative for .~ulaPial pau~asites at 2b.h and the other two at ~Sh. Two patients had CQ & DEQ at Oh due to previous treatT0ent With the dru~; CQ was absorbed in all patients after each dose and increased levels of both CQ and DEQ were det~eted 2H after each dose. However there was wide variation in the absorption. The peak level of CQ (367 ~_ io7 ng/ml) was seen at 26h in 7, 28h in 3 and 1 patient each at 2 and 52h. DEQ showed a slmilar plas.~ c o n e e n ~ t l o n profile and and the DEQ/CQ Patio varied from 0.25-0.72. Seven patients had PiEo~s on day i; of them 5 had a better absorption on day 2 than on day i. as measLtr~d by AUC.

Of the 5 Without ri~ors. ~ had a bettel- absorption on d~v I. There was wide variation in both absorption and m~tabolis~ of oral ohloroquine du~in~ tr~%ment fop acute uncomplicated malaria; riKors may contribute to the variation in absorption. Howeve~ absorption wa~ sufficient for eradication of the parasite. Faculty of Medicine. PO Box 271. Colombo 8. S~I LANKA

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PP 01,07

PP 01.09

THECLINICALSIGNIFICANCEOFCHOLINESTERASEINHIBITIONBYMETRIFONATE Y. A. Abdi. L. L. Gustafsson. O. Ericsson and M-L. DahI-Puustinen Metrifonate (M) is given in 3 doses of 7.5 mg/kg at 2 week intervals due Io its inhibitory effect on plasma and red blood cell (rbc) cholinesterases (ChE)(Plestina R, Davis A and Bailey DR. Bull Wld Hlth Org. 1972, 46" 746-759). The clinical relevance of this inhibition is not known. We investigated the dose-response relationships between the effect of M on rbc and plasma ChE levels and cholinergic symptoms. Single doses of 2.5, 5, 7.5 and 15 mg/kg were given to 16 healthy subjects (4 in each group). The drug was administered at 8 a.m. Blood samples were collected for the analysis of plasma and rbc ChE expressed in pmol/s.The AUCs of the ChE curves of the first 8 hours were calculated. Side effects were monitored during the same period. Saliva secretion was measured at 4 time points during day 0 (preceeding day) and day 1 (treatment day) as % increase on day 1 compared to day 0 (Pech RE. Arch. Gen.Psychiatry 1954,1:3540). The mean AUCs of the plasma ChE of the four groups were 591, 285, 219 and 220 pmol/s x h respectively.The corresponding rbe ChE figures were 1334, 1205, 1116 and 867 pmol/s x h. Plasma ChE was maximally inhibited after 7.5 mg/kg. There was a linear correlation between inhibition of rbc ChE and dose (r=0.99). Eleven subjects had mild or moderate side effects but one volunteer (being slow hydroxylator of debrisoquine) taking 15 mg/kg had severe nausea, vomiting, abdominal colic, dizziness, headache and diarrhea. A modest increase in salivation was noted at doses above 2.5 mg/kg. Plasma ChE appears to be maximally inhibited by M already at 7.5 mg/kg, while rbc ChE inhibition is linearily related to the doses tested.There was no correlation between the degree of ChE inhibition and the occurrence of side effects or increase in salivation. Dept.of Clinical Pharmacology,Huddinge Hospital, S-141-86 Huddinge,Sweden.

COMPARISON OF PIROXICAM AND TENOXICAM ENTEROHEPATIC RECIRCULATION C. Benveniste, R. S t r i b e r n i and P. Dayer E n t e r o h e p a t i c (EH) r e c i r c u l a t i o n of NSAIDs m a y play a role in their intestinal toxicity. In order to assess the extent EH r e c y c l i n g of two oxicam-type NSAIDs, piroxicam (PX) and tenoxicam (TX), we compared their p h a r m a c o k i n e t i c s in a b s e n c e and p r e s e n c e of c o n c o m i t a n t c o l e s t y r a m i n e (CS) administration. METHODS: Six healthy volunteers received (randomized crossover design) PX 20 mg and TX 20 mg orally, alone or w i t h CS ~24 g / d a y from the 4th hour until day 4). Plasma drug c o n c e n t r a t i o n s were d e t e r m i n e d (HPLC-UV) for 168 h. R E S U L T S : Cma x of PX and TX were r e s p e c t i v e l y 6.38 (SD 0.69) ~mol/l and 7.66 (1.6) ~unol/l; c o r r e s p o n d i n g tma x were 1.83 (0.75) h and 1.33 (0.51) h. CS reduced PX and TX t% by 2-folds: 50.3 (15.6) h vs 28.1 (9.3) h and 7 3 . 6 (21.5) h vs 35.8 (16.0) h, r e s p e c t i v e l y . CS increased apparent oral clearance (CI/F) of PX and TX b y b~ % and 112 %. D u r i n g CS a d m i n i s t r a t i o n PX and TX t89 were c o r r e l a t e d (r = 0.89, p < 0.05). This strongly suggests that their liver oxidations, the m a j o r b i o t r a n s f o r m a t i o n route for both drugs, are under a c o m m o n control. CONCLUSION: PX and TX are e x c r e t e d to a large and comparable extent through the biliary route. Intestinal s e q u e s t r a t i o n of oxicams by CS may thus help to accelerate their e l i m i n a t i o n in case of toxicity. Clinical Pharmacology, Geneva University Hospital, CH-1211 Geneva 4, S w i t z e r l a n d

PP 01.08

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C L I N I C A L TRIALS OF HEPATITIS CURE W I T H P R O T O B E R B E R I N E A L K A L O I D S OF E n a n t i a c h l o r a n t h a P. Virtanen, T. Njimi and D. Ekotto M e n g a t a P r o Z o b e r b e r i n e alkaloids from the b a r k of E n a n t i a c h l o r a n t h a has b e e n u s e d for h e a l i n g of jaundice in C a m e r o o n folk medicine. The a l k a l o i d c o m p o s i t i o n of c h e m i c a l l y separated extract has been d e t e r m i n e d (P. V i r t a n e n et al., A c t a anat. 131, 166, 1988; L. Jalander et al., A c t a Chem. Scand., submitted) and laboratory animal studies w i t h artificial liver injury were done in order to optimize the therapeutic dose and to ensure the safety (P. V i r t a n e n et al., A c t a anat. 131, 166, 1988; ibid 132, 159, 1988; ibid 1989, in press). The dose of alkaloids, called Hepasor, c h o s e n for treatment of patients w i t h jaundice did not e x c e e d daily 3 mg of Hepasor per kg b o d y weight, w h i c h v a l u e was used in animal studies. The clinical evaluations of 52 p a t i e n t s (29 males, 23 females aged from three months to 53 years w i t h a m e a n age of 34 year) and s t a n d a r d tests like, Gross, Hanger's, Maclagan's, Kunkel Phenol and A u s t r a l i a antigen were done before and after H e p a s o r treatment from the m a j o r i t y of patients. E x c l u d i n g one exception, in all other cases b o t h the tests p e r f o r m e d and doctors survey v e r i f i e d the complete r e c o v e r y after 2 weeks of the H e p a s o r treatment. The more d e t a i l e d b i o c h e m i c a l assays were done for 7 p a t i e n t s w i t h a m e a n age of 34 years. The tests a s s a y e d were: S-ALT, S-AST and S-BIL. The results o b t a i n e d showed thaL after 2 weeks of the H e p a s o r treatment there was 3• fold decrease in S-BIL, 15• fold decrease in S-ALT and 25• fold decrease in S-AST values b e i n g after the treatment all in normal levels. Sorep SA, BP 2009, Yaounde, C a m e r o o n

A CLINICAL TRIAL COMPARING PtROXICAM AND DROXICAM IN OSTEOARTHRITIS OF THE SPINE. Bohl~D.;Gausmann,H.;Vorberg~G.;Sanchez~ J .;Garcia-Barbal,] .; Reuter,C and Harrison,F.J.J. This double-blind clinical trial compares Piroxicam (P) and Droxicam (D) (new NSAID, prodrug of (P)). After a 7- day running placebo period, 30 patients (18m;12f) with O.A. of the spine (EULAR critereia), mean age 53.5 years +-11.2, were randomized to receive 20 mg/day of (P), or 20 rag/day of (D) for 8 weeks {wk). Patients were controlled at week 0, and at the end of weeks 2,4,6, and 8. Pain intensity, articular index, duration of morning stiffness, and ability to perform daily activities were evaluated. Both drugs induced improvement over pain WAS) intensity during the trial ((D) p<0.01 at wk 2, p<0.001 wk 4-8; (P) p,0.001 wk 2-8). Patients in the (D) group showed a progressive inprovement in the "frequency of pain exacerbation", pain intensity (descriptive scale), pain in motion, nocturnal pain, pain after getting up, pain after 30 min. standing, duration of morning stiffness and articular index (p<0.01 at wk 2, p
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INTERACTION BETWEEN THE NSAID TENOXICAM AND LITHIUN B. M~ller-Oerlinghausen, H.-P. Breuel S~me nonsteroidal a n t ~ l ~ r y drugs (NSAID) h a v e been shown to reduce the renal lithium clearance with the possible consequence of lithium i n t o x i c a t i o n . S i n c e about I%. of the general population are receiving lithium s a l t s , new NSAIDs must be checked, whether they show this kind of i n t e r a c t i o n . An open t r i a l was performed in 11 healthy male volunteers aged 2 3 - 3 4 years t o investigate changes of lithium concentrations in plasma and urine a f t e r additional daily application of 20mg tenoxicam. The 1 2 - d a y interaction phase was preceded by a 1 0 - d a y or, in some cases, 12-day lithium treatment p h a s e . Diet including sodium input was standardized. In this interaction p h a s e , the lithium steady state concentration increased by a mean 18.4%, while the lithium clearance decreased by a mean 12.7%. Lithium excretion in urine did not increase, t I/2 B increased from 17.2h (day 9) to 37.5h (day 22). Finger tremor increased during the interaction p h a s e . I n t e r e s t i n g l y , there was no uniform response of lithium plasma concentrations to the additional administration o f t e n o x i c a m : In 2 subjects, li-

NO EFFECT OF NAPROXEN (NPXN) ON THE DISPOSITION OF METHOTREXATE (MTX) IN PATIENTS WITH RHEUMATOID ARTHRITIS C.F. Stewart, R.A. Fleming, W.E Evans Previous case reports have described increased toxicity with the co-administration of MTX and nonsteroidal anti-inflammatory agents. The preseht study of 15 patients with rheumatoid arthritis (median age 56; range 34-78 years) was performed to compare the disposition of MTX alone or with concomitant NPXN. Patients with significant renal disease (SCr > 1.4 mg/dL or CrCI < 30 mL/min) were excluded from the study. The study was a nonblinded, crossover design, consisting of four treatment arms: arms I and IV - patients received MTX 15 mg orally and intravenously, respectively; arms II and Ill - patients received MTX 15 mg orally and intravenously, respectively while receiving oral NPXN 500 mg every twelve hours. Serial blood samples and urine were collected for 24 hours after the MTX dose. MTX concentrations were determined by a radioenzymatic assay technique. AUC 0 - > O O w e s calculated using the trapezoidal method and CI s was calculated as dose/AUC. Bioavailability (F) was calculated as (AUCpo/AUCiv)*I00. MTX C1 s was evaluable in 12 patients with NPXN (6.2 • 2.1 L/hr) and without NPXN (6.8 i 2.9 L/hr) (p=0.41; a=0.05; K=0.2). MTX CI/F was evaluable in 13 patients with NPXN (9.7 i 3,3 L/hr) and without naproxen (10,6 • 4.1 L/hr). (p~0.19; a=0.05, ~=0.2). No statistically significant differences were observed in MTX bioavailahility (p>0.2; Wilcoxon test). No toxicity was observed when patients received MTX with NPXN as compared to MTX alone. As determined by this study, naproxen does not alter the apparent oral or systemic clearance of low dose MTX when given concomitantly in patients without significant renal disease. Department of Clinical Pharmacy, Univ of TN, Memphis, 26 S. Dunlap Rm 202, Memphis, TN 38163.

thium plasma levels increased by 41% and 51%, whereas in 3 subjects they remained fairly constant during the interaction phase. Department of Psychiatry, Free University of Berlin, Eschenallee 3, D-IO00 Berlin 19; AFB Klinische Pharmakologie GmbH B e r l i n ,

KurfOrstendamm 217, D-IOOO Berlin 15.

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PP 01.12 INDOMETHACIN DOES NOT I N C R E A S E L E U K O T R I E N E IN STII~IULATED HUI~aN NEUTROPHILS.

B~ FOPdVIATION

J. L. Pinquier, C. Lejus, M. Delaforge, F. Gaisne G. Strauch, D. Mansu~. Nonsteroidal antiinflammatory drugs (NSAID) inhibit cyclooxyge~ase metabolism from arachidonic acid (AA). Some authors have suggested that NSAID may increase lipoxygenase (LO) products by deviation of AA metabolism. These hypothetical increases in leukotriene (LT) production by the human polymorphenuclear cell (HPMN) could explain the NSAIDs-hypersensitivity seen in some asthmatic patients. Recently J.C. Docherty & T,W. Wilson (Biochem.Biophys.Res.Commun.,148:534-538,1987) have observed in-vitro a 300% increase in LTB4 production by Stimulated HPMN in presence of therapeutic concentrations (O.1-1pM) of indemethacin (IND). We studied in-vitro LTBq production of HPMN stimulated by calcium ionophore A23187 (n=5) for I0 min after a 5 min preincubation in IND solution (0 to 280 pM). We also studied ex-vivo LTB4 production in 6 healthy volunteers before and after 5 daily oral doses of IND (75mg). LTB4 and its metabolitea were measured by HPLC with PGB2 as internal standard. We considered LTB4 production as being the sum of the measured LTB4 and its metabolites. IND did not increase in-vitro LTB4 production at low concentration and we found a L0 It50 (105 BM) as previously reported. Ex-vivo studies showed no changes in LTB4 production after IND (213• vs 182• ng/107 HPMN, NS), We have found that, in healthy volunteers, both in-vitro and ex-vivo, IND does not increase HPMN LTB4 production. Since LTB4 is very quickly metabolised into WOH-LTB4 and WCOOH-LTB4, these were included in measuring all LTB4 production. This may explain the discrepancy between our results and those measuring only LTB4 by RIA. Further study with HPMN from patients suffering of NSAIDshypersensitivity to test the AA metabolism deviation hypothesis is needed. IRT-ECLIMED Hopital Cochin 75014 Paris FRANCE & CNRS UA400 Facult@ des Saint-P~res 75006 Paris FRANCE.

CARDIOVASCULAR EFFECTS OF DICLOFENAC

SODIUM &

PIRPROFEN M . H . M . A i y , Z.I. Guirgis, A. Khattab, A-El Gazzar & N.N.Zaki The present work was designed to investigate the effects of two NSAID's namely diciofenac sodium and pirprofen on the isolated aortic strip either intact or denuded and the isolated perfused heart of rabbit. The effect of each drug was tested on the arterial blood pressure, EGG and on the impulse transmission in the superior cervical sympathetic ganglion in intact chloralosed cats. Morover, the modulatory effect of the test drugs on the response of the above mentioned preparation Qn-vivo & in-vitro) to different drugs e.g. epinephrine, norepinephrine isoprenaline, and abgiotensin [i was studied. 9 and pirprafen selectively potentiated the contractile response of the aortic strip preparation induced by epinephrine and narepinephrine without affecting contractile responses induced by angiotensin ]J or histamine. This potentiating effect could be abolished by reserpinization or by removal of the intirnat endothe]ium. Pirprafen was devoid of any effect on isolted perfused rabbit heart preparation whereas diclofenac in high concentrations elicited a positive inotropic effect. The data revealed that diclofenac and pirprofen in a wide range of concentrations are devoid of any significant effect on arterial blood pressure or ECG in intact anaesthetized cats. However, both drugs were found to potentiate the pressor responses to epinephrine and norepinephrine effect which could be suppressed by reserpinization. Dept. of Pharamoology, Faculty of Medicine (Bertha), BENHA, EGYPT.

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C~ARATIVE STUDY OF D I P Y R ~ (i and 2 ~), DICiQFENAC AhD PETHIDI~ U ~ COLIC. R. Pal%0, M.J. Gonz/zlezde Suso, F. Garcia-Alonsoand Collaborative Gro~0 of the Spanish Society of Clinical Pharmacology. Ministry of Health. Madrid. Spain. A randomized double blind multieentre clinical trial was designed t~ ccaloarethe ar~esic efficacy and incidence of adverse effects of Dip~ (i and 2 &~), Diclofenac and Pednidineb~ inh~uscular rout% in anute renal colic. Methods The clinical trial was or~er~zed by the Rei~ulatoryAuthority in coordinationwith the Spsnish Society of Clinical Pharmacolo~. The study was carried, out on 451 paciente from the emergency services in 13 Spanish Hospitals. Ureter-alcolic was diagnosed by clinical e x ~ t i o n , urine analyses or when dne presence of ureteral calculus was confirmed. The dru~ treatment groups were : gro~o I : Dipyrone 1 ~ (n=l16), group II : Dipyrcne 2 ~ (n=lOl), ~ III : Diclofenae 75 mg (n=l16), group IV : Pet~lidinei00 m~ (n=ll8). All drugs were administered in ane dose by the intrgmuscularroute. The intensity of pain was measured by physicians and also by patients using visual analogue scales. The main paraneter of efficacy was the necessity of rescue treatment (Pethidine ICO rag) 30 minutes after experi~mtal trea~nt. The size of the sa~ole was estimated so that the statistical power "a posteriori" for each pair of treai~ent was greater than 01'80, Result% Rescue treai~ent was required in a total of 93 paeient% which represented the followi~ percentage in each trealznentgroup which were not statistically differents : I: 24.1%; II: 22.~/~; III : 16.~Z; IV: 19.~/~. In the remaJz~g patients no statistical differences between ~ea~rent% were observed as measured with the visual analo gue scales. The total number of side effects recorded was 768 and this was ~eater in Pethidine treated patients. Conclusions The results obtained su~ast that there is no reason to use Pethidine as first choice in ureteral colic. Its clinical efficacy is similar to that observed with the other treatmentswhich do not produce some of dee serious side effects (conft~ion/ha/lucip~tions, orthestatic h~qsotensien,nausea/vomiti~) observed with Pethid~ne. Additional observationsare that the use of Dipyrone 2 ~ is in~ustifled as Dipsrrone1 ~ . is equally effective and that Dielofenaeis a valid alternativewhich shows similar analgasie efficacy.

IDENTIFICATION AND SIMULT&NEOUS ANALYSIS OF NON-STBROIDAL ANTI-INFLA~4ATORY DRUGS BY HPLC F. Lapicque, B. BdxLnwarth, P. Netter, P. Gillet, P. Tr~ehot, H. Lamber%, R.J. Royer

-

-

PP 01.16 ~ Z E D OF D I P ~

DOUBLE-ELI~ P I A C ~ T ~ TRL%L AND ASPIRIN IN POST-OP~ATIVE DENTAL PAIN

Dwiprahasto I, *Rochim A, *Soelistiono, **Kalhammer R, & Santoso B 1)apt. Clinical Pharmacolog 9 *Dept. Oral Surgery, Gadjah Mada University,Yogyakarta-Indonesia and ** Hoechst AG, Frankfurt-FRG

Dipyrone has h~en used as an established analgesics in many parts of the world, but there are only limited comparative data regarding its efficacy against other analgesic drugs. This study, therefore, was designed to investigate the analgesic efficacy of dipyrone in comparison to aspirin and placebo in the treatment of post-operative dental pain. One hundred patients of both sexes, between the ages of 18 to 40 years with post-operative pain following the extraction of a lower impacted wisdom tooth, were recruited for this study. They were randomly assigned into three groups, receiving either dipyrone (I-2 x 500 mg - 34 patients), aspirin (I-2 x 500 mg - 34 patients) or placebo (32 patients). The analgesic efficacy was evaluated by subjective assessment of pain intensity and pain relief as experienced by the patients at hourly-intervals within 8 houq[s after the administration of either drugs or placebo. An attempt was made to grade the pain intensity on a 4point scale (0= no pain, 1 = m i l d , 2 = moderate, 3 = severe and 4 = very severe). Similarly, the degree of pain relief was also self expressed according to a 4-point scale (0 = no relief, I= slight, 2 = moderate, 3 = a lot, and 4 = complete). The results showed that patients in the dipyrone or aspirin treatment groups demonstrated a significantly less pain intensity compared to those in the placebo group (p<0~01). &~ne pain relief achieved in the dipyrone and aspirin treated groups were also significantly greater (p<0.01) compared to the placebo group. However, the analgesic efficacy of dipyrone as assessed by pain intensity or pain relief scores was significantly greater (p<0.01) than that of aspirin throughout the assessment period. The adverse events experienced by patients in the dipyrone and aspirin treated groups were si~uilar.

Non-steroidal anti-inflammatory drags (NSAIDs) are widely used in inflammation and pain associated with various forms of arthritis. Their identification in plasma is suitable in pharmacological studies for testing the wash-out or the compliance, and in toxicological analysis. An HPLC assay was developed for the simultaneous determination of 16 NSAIDs in biological fluids (plasma, synovial fluid...). The sample was acidified and extracted by diethyl ether after addition of benzoyl-4 phenyl-2 butyric acid as internal standard (IS}. Elution was achieved on a Nova Pak C 18 (300x3.9mm, Waters) column using a mobile phase of acetonitrile/acetic acid 0.3 /tetrahydrofuran (36:63:1) and detecting wavelength of 254 and 370 mm. The following NSAIDs can be identified by their respective retention times : tenoxicam (3.Z0mn), sulindae (7.42), piroxicam (7.97), tiaprofenic acid (i0.92), ketoprofen (12.62), naproxen (13.28), fenbufen (16.22), diflunisal (17.83), pirprofen (22.48), fenoprofen (26.85), etodolac (30.03), flurbiprofen (31.28), niflumic acid (32.67), diclofenac (41.42), indomethacin (42.83) and ibuprofen (45.50), relatives to IS (21.27). The reproducibility, repeatability, linearity and specificity were found to be satisfactory. The method #ms applied to blind analysis of plasma of patients treated or self-poisoned with some of the drugs investigated. D~partement de Pharmacologie Clinique, URA CNRS 1288 Faeult~ de M~decine, 54505 Vandoeuvre les Nancy (France)

PP 01.18 INDOLYL THIAZOLIk~L CHALCONES AS POTENT ANTIINFLAMMATORY AGENTS Ashok Kumar ,nd B.P.Jalu ~Clinically useful anti-inflammatory drugs Indomethcin and Sulindac possess the potent pharmecodynamic Indole nucleus. Furthermore, recent researchers have elan reported the diverse type of b i o l o g i c a l activities viz enti-infl~mmatory, hypotensive and anti-parkinsonian in t h i s n u c l eus. These observations prompted us to s y n t h e size e series of Indolyl Thiazolinyl Chalcones with a view to develop better anti-inflammatory drugs. The structures of these compounds were confirmed by spectrometry. These compounds were e v o l u a t e d for their ~nti-inflsmm~tory ~ctivi ty ~gelnst carregeenin induced paw oedema in albino rats by adopting t h e m e t h o d o f W i n t e r et. el. 1962. Some compounds have shown interesting activity. The most active member of this series was "2Fluoro2-(5-methyl-4-oxo-5-thiezolidinyl)-2methylindol-3-yl-methyleneimino Chalcone. This compound was further evaluated in d e t a i l and found to be more potent than phenylbutazone in o u r p r i l i m i n a r y studies. Moreover, this com pound (12) a l s o e v a l u a t e d for ED50, ulcerogenic activity, CNS effect and acute toxicity. The ALD=0 of this compound was quite high ( I000 mg/~g p.o.) indicating a high margin of safety. Moreover, further work on this compound can lea d to t h e d e v e l o p m e n t of a clinically useful anti-inflammatory agent. Department of Pharmacology, L.L.R.M. Medical College, Meerut(U.P.)-250004 INDIA

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EVAIIATIGNG~ ~ ~ ~ C 6 ] E > A ~ I T I S (F ~ h-~E. M_ L. Mm
DOUBLE-BLIND, SINGLE-DOSE EVALUATION OF A C E T A M I N O P H E N 500MG, 10O0MG, 1500MG, 200OMG, A N D P L A C E B O IN T H E T R E A T M E N T O F P A I N F O L L O W I N G O R A L OR PERIODONTAL SURGERY D . R . M e h l i s c h t W . I s a a c s r P. B r o w n a n d L . S h a f f e r

I2SIN~ ( I C h ~

ASPIRIN

SIG~I~TCAkt ~ N.S. 0.0001 0.0(81 0.0001 Lysine cloni,xflmte i s ~ r e e f f e c t i ~ ~ m.rh b e t t e r tolerated d~an aoetylsalicylic acid in the o ~ n ~ l of acute inflam~tory msnifestaof knee o s i r i s . M. L. Mm'ti, thi~rsity of ~ Aires, Ayacudm 1490 - 1~ piso - IIIi - ~ { ~ s m_~os - Ar~tina. s 2nJ Day 7th Din] 15th Day

8.64 + 4.17 + 1.45 + 0.45 +

4.]5 2.7 2.2 1.47

9.81 + 3.2 7.42 + 3.5 4.9 + 3,25 3.77 _+ 2.9

This multi-center, randomized, double-blind study w a s c o n d u c t e d in t w o d e n t a l p a i n m o d e l s , t h i r d molar and periodontal surgery. Patients evaluated b a s e l i n e p a i n a n d s u b s e q u e n t e v a l u a t i o n of p a i n at 89 I, 2, 3, 4, 5 a n d 6 h o u r s a f t e r t a k i n g t h e Study medication. Rescue medication would be taken I hour afs dosing for inadequate pain relief. A t o t a l of 349 p a t i e n t s w e r e e n t e r e d i n t o t h e s t u d y a n d 299 w e r e i n c l u d e d in t h e e f f i c a c y a n a l y s i s (184 p e r i o d o n t a l s u r g e r y a n d 115 oral surgery). There were five summary m e a s u r e s : SPID, M A X P I D , H O U R S ( h o u r s i n i t i a l p a i n w a s 89 g o n e ) , T O P A R & M A X P A R . A t w o - w a y (drug, i n i t i a l p a i n ) a n a l y s i s of v a r i a n c e s h o w e d a significant difference among drugs with respect to s u m m a r y m e a s u r e s ; h o w e v e r , p a i r - w i s e c o m parisons showed that the only significant differences were between each active drug and placebo. This same analysis was performed for oral surgery and periodontal surgery patients separately. No significant differences were n o t e d b e t w e e n e a c h d o s e of a c e t a m i n o p h e n , there was a tendency toward a dose response. This m a y h a v e b e e n i n f l u e n c e d b y an i n s u f f i c i e n t p o w e r d u e to t h e n u m b e r of p a t i e n t s e n r o l l e d . Acetaminophen, an e f f e c t i v e a n a l g e s i c f o r o r a l surgery and periodontal surgery pain, demonstrated relatively little difference between d o s e s of 5 0 0 m g , 1 0 0 0 m g , 1 5 0 0 m g a n d 2 0 0 0 m g in this study. B i o m e d i c a l R e s e a r c h G r o u p , I n c . , 1 5 0 0 W. 3 8 ~ h S t r e e t , #51, A u s t i n , T e x a s , U S A 78731

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CP-66,248-2, A NEW NSAID FOR THE TREATMENT OF POSTOPERATIVE, POST-FRACTURE OR POST-TRAUMA PAIN A. Sunshine, A. Colon, E. O'Neill, N.Z. Olson, L. Gonzalez, h Ramos, and L. Loose The oxindole, CP-66,248 is a new chemical entity with a unique combination of both potent in vitro and in vivo lipoxygenase and cyclo-oxygenase inhibitory activity and is considered a potential new nonsteroidal anti-inflammatory/analgesic agent. The sodium salt formulation of CP-66,248 (CP-66,248-2) has a Tma x of 1-3 hours. The purpose of this single dose double-blind study was to determine the analgesic activity of three dose levels of CP-66,248-2 (Sodium salt formulation) 60mg, 80mg and 120mg when administered orally to 150 patients with postoperative, post-fracture or post-trauma pain in comparison to aspirin 650rag and placebo. Subjects rated their pain intensity and relief periodically for 6 hours post-dosing. Analgesia was measured on the basis of standard subjective scales for pain intensity and relief, a number of derived variables based on these data and global measures. All active treatments were better than placebo. There was a dose response of CP-66,248-2 between the 60rag and 80rag dose; thereafter there was a plateau effect. At 80mg and 120mg, CPt~ti,248-2 ilao mean analgesic scores comparable to aspirin With 80mg at certain time points being greater than aspirin. CP-66, 248-2 is an effective analgesic compound with both lipoxygenase and eyclo-oxygenase inhibitory activity. NYU Medical Center, 907 Fifth Avenue, New York, NY 10021, USA

MRI TOMOGRAPHY IN COMBINATION WITH EXPERIMENTAL HAEMATOMA: A NEW CLINICAL PHARMACOLOGICAL ANTIINFLAMMATORY DRUGS.

MODEL

FOR THE

STUDY

OF

B. M_~ G_i_an n e t_t_!L 3 ~_A_s_sh e_u_er__L_H_=_Pa_b_s_t_L _M ~_K_t_e! n o-

In a placebo controlled double blind trial with intraindividual comparison studied using the

the model

effect of a 2 ~ Aescin-Gel of experimental haematoma o f

was the

forearms and evaluating the lesions with MRI tomography. Verum treatment was allocated at random either to the right or the left forearm, the other side being treated with placebo. Planimatric evaluation of the lesion areas was performed on 5 consecutive days after the start of the study. At the same time tenderness was measured by a toncmeter. 19 of 20 included volunteers completed the study, One dropped out because of claustrophobia. Under previously determined standardized conditions lesion areas and their decreases were measured and compared between the two treatments by paired t-test. Decrease of lesion areas was significantIy faster under verum treatment (p ( 0 , 0 5 ) and was c o r r e l a t e d with decrease of tenderness.

Thus the measurement of lesion areas by MRI tomography combined with the standardized conditions of experimental haematoma could provide a first sensitive, objective, quantitative and d[r_e&~ evaluation of pharmacological effects of antiodematous and/or antiinflammatory acting drugs in clinical pharmacology. Medizin I, Dr. Madaus GmbH 5000 K~In 91

& Co., Ostmerheimer Str.

198,

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PP 01.25

INTESTINAL ABSORPTIONAND PRESYSTEMIC ELIMINATIONOF AJMALINE AND PROPRANOLOL IN RATS WITH ACUTE RENAL DYSFUNCTION M. YASUHARA, Y. HASHIMOTO, H. HIRAOKA and R. HORI I t has been demonstrated that the presystemic ( f i r s t pass) e l i m i n a t i o n o f c e r t a i n drugs is reduced in patients with renal failure. The purpose of this i n v e s t i gation was to c l a r i f y the mechanism of increased a v a i l a b i l i t y of drugs which are subject to an avid f i r s t pass e x t r a c t i o n in the l i v e r . The renal dysfunction was induced in male Wistar rats by s.c. injection of uranyl nitrate or by b i l a t e r a l ureteral ligation. Renal dysfunction did not cause any change in the ajmal i n e blood concentration a f t e r an i.v. dose (2 mg/kg), but i t increased the ajmaline blood concentration after an intraduodenal dose (I0 mg/kg) about 2 . 8 - f o l d , the a v a i l a b i l i t y of ajmaline being 41.1% and 16.7 % in rats with renal dysfunction and control rats, respectively. The blood concentration during intraportal infusion was s l i g h t l y increased in rats with renal dysfunction. The apparent hepatic e x t r a c t i o n r a t i o of ajmaline at an infusion r~te o f 0.05 mg/min/kg was 78.8 and 82.9 % in renal dysfunction and control rats, respectively. At a higher infusion rate (0.25 mg/min/kg), i t decreased to 58.6 and 66.2 %, r e s p e c t i v e l y . The i n i t i a l absorption rate of ajmaline from the small intestine determined by in situ loop method was s i g n i f i c a n t l y increased in rats with r e n a l d y s f u n c t i o n compared with c o n t r o l r a t s . S i m i l a r experiments with propranolol revealed the nonl i n e a r hepatic e x t r a c t i o n and the increased i n t e s t i n a l absorption in rats with renal dysfunction. These r e s u l t s suggest that the increased a v a i l a b i l { t y of ajmaline and propranolol in renal dysfunction is caused, at l e a s t in p a r t , by i n c r e a s e d a b s o r p t i o n r a t e in the i n t e s t i n e and n o n - l i n e a r e x t r a c t i o n in the l i v e r . Department o f Pharmacy, Kyoto U n i v e r s i t y H o s p i t a l , Sakyo-ku, Kyoto 606, Japan

R E N A L C L E A R A N C E OF C Y C L O S P O R I N E AND T H R E E OF ITS METABOLITES IN RENAL TRANSPLANT PATIENTS. W.M. Awni, K.L. Heim-Duthou B,L, Kasiske Cyclosporine (CsA) is extensively metabolized in humans and animals. Although it is known that the kidney is responsible for only a small portion of CsA excretion, the renal handling of CsA metabolltes has not been well characterized. We examined the renal clearances of CsA and its MI, MI7 and M21 metabolites at steady state in 81 renal transplant patients (age 43• years [mean~+SD]) at 11• days post CsA initiation. Pharmacokinetic studies of CsA and its 3 metabolites which included 8-10 whole blood samples and total urine collection during a 24-hour period were conducted in each patient. CsA and its metabolites were measured in whole blood and urine using HPLC. The mean (• renal clearance of CsA (2.0• mL/min) was much lower than that for MI7 (10.0• mL/min), MI (6.8• mL/min) and M21 (11.7• mL/min). While the renal clearances of CsA and its metabolites were significantly dependent on CsA dose, the renal clearance of CsA was also significantly dependent on urine flow, suggesting that CsA, but not its metabolitea may undergo passive tubular reabsorption in the kidney. No other clinical parameters (creatinine clearance, sex, age, hematoerit or weight) correlated with the renal clearances of CsA, MI, MI7 or M21. Conclusion: Unlike CsA, a significant proportion of CsA metabolites is e l i m i n a t e d by the kidney. Thus, alterations in renal function may affect the efficacy and/or toxicity of CsA by changing the blood levels of CsA metabolites.

PP 01.24

PP 01.26

PHARMACOKINETICS

OF WARFARIN IN NEPHRECTOMISED RATS.

Y.A. Boateng, T.R. MeCappin, H.E. Barber, S. Heys~ P.H. Whiting and J.C. P e t r i e . The phas of warfarin was studied in rats with chronic renal f a i l u r e (CRF). Male Sprague-Dawley rats (290-460 gm) were assigned to treatment and c o n t r o l groups. CRF was induced by 5/6 nephcectomy i n v o l v i n g removal o f one kidney and l i g a t i o n of two of the three branches of the c o n t r a l a t e r a l renal a r t e r y . Control rats underwent laparotomy. Pharmacokinetic studies were c a r r i e d out three weeks post surgery with rapid I.V. i n j e c t i o n of racemic warfarin (lmg/kg). Warfarin concent r a t i o n s were determined by HPLC (A.M. Breckenridge, Br. g. Pharmac. 84, 081-091, 1985). Pharmacokinetic parameters are shown below (mean • S.D.) Laparotomies(n = 5) Nephrectomies(n= 5) Statistical Vd(ml) Vc(ml) Clp(ml/min) t89 (min)

51.74 17.94 0.578 63.98

• • • •

6.92 4.41 0.151 11.22

53.33 22.60 0.540 81.50

• 15.28 • 5.56 • 0.298 • 34.20

signi~cance n.s, n.s. n.s. n.s.

(KEY: Vd = Volume of distribution, Vc = volume of central compartments, tip = plasma clearance~ t89 = terminal half-life, n.s. = not significant). The absence of significant differences in the pharmacokinetic parameters is consistent with the very mild degree of CRF induced, as measured by plasma urea and ereatinine. We have previously shown (H.E. Barber, Br. J. Pharmac. (1988), in press) significant increases in Vd and Vc in rate with the more severe glycerol-induced acute renal failure model. Department of Medicine & Therapeutics, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen AB9 2ZD, Scotland.

H e n n e p i n County Medical Minneapolis, MN 55415

Center,

701

Park

Avenue,

EFFECT OF RENAL FUNCTION ON THE KINETICS OF EPININE AFTER SINGLE ORAL DOSES OF 200 mg IBOPAMINE H. Wesche, J . B o e l a e r t , C. de Mey & I. Meineke. Ibopamine is an oral precursor o f epinine (E), i t s active moiety, used in the treatment o f congestive heart f a i l u r e . E is m e t a b o l i c a l l y cleared via o x i d a t i o n or conjugation with s u l f u r i c acid. The pharmacokinetics o f unconjugated ( f r e e : FE) and conjugated + f r e e E ( t o t a l : TE) were assessed a f t e r an oral dose of 200 mg ibopamine in 24 agematched patients with various degrees of renal dysfunction ( c r e a t i n i n e clearance, CrCl 6-106 ml/min). Plasma FE rose r a p i d l y (Tmax 30-75 min) and then f e l l sharply. L i t t l e FE could be found beyond 2 hrs a f t e r dosing. CrCl did not s i g n i f i c a n t l y influence the k i n e t i c s of FE. Plasma l e v e l s of TE rose more slowly, and the k i n e t i c s o f TE were c l e a r l y affected by renal dysfunction. Cmax (range: 3.7 to 30.6 mcmol/l) was i n v e r s e l y c o r r e l a t e d with CrCl (I/Cmax vs CrCI: slope S:0.0015; i n t e r c e p t I: 0.052; r : 0 . 9 0 3 ) , as was the AUC(O-48h) (range: 15 to 729 mcmol.h/l, I/AUC vs CrCl : S:0.0006; I : - 0 . 0 0 3 ; r: 0.949), and the Mean Residence Time (range: 3 to 39 hrs, 1/MRT vs CrCl : S: 0.0023; I: 0.024; r: 0.900). The renal clearance was d i r e c t l y correlated with the CrCl (CLr vs CrCI: S:0.0661; I:-0.18; r: 0.880), as was the terminal rate constant K (range: 0.026 to 0.464/h, K vs CrCl: S:0.0032; I:0.0115; r: 0.912). The urinary recovery (amount excreted,~Ae) was not affected (range: 72 to 286 mcmol, Ae vs CrCl: S: -0.205; I: 132; r:-0.17). In conclusion, renal dysfunction did not alter the kinetics of unconjugated epinine, but i t s i g n i f i c a n t l y impeded the elimination of the epinine conjugates. As there is no evidence of a c t i v i t y f o r these conjugates, there seems to be l i t t l e need for a dosage adjustment of ibopamine in patients with renal dysfunction. As a general safeguard, dose reduction might nevertheless be considered at CrCl levels < 10 ml/min. Address: Algemeen Ziekenhuis St.-Jan, Brugge, Belgium; SK&F-Institute of Appl. Clin. Pharmacol. G~ttingen, FRG.

A 128

PP 01.27

PP 01.29

PHARMCOKINETICS AND DOSAGE REQUIREMENTS OF SUNI165, A NEW ANTIARRHYTHMIC AGENT, IN RENAL FAILURE T. Takahataks~ H. Ohta~ Y. Yamamoto r Y. Ishida ~ H. Hara r S. Nakamura~ Y. Ushiogi~ N. Hashimotsp S. Satoh r T. 8asaki~ Y. Yamada~ K. 0htap H. Ise and N. Hattori Since 8UN1165, N-(2,6-dimethylphenyl)-8-pyrrolizidine acetamids hydroehloride hemihydrate, is mainly excreted by the kidney, we investigated its pharmacokinetics in 32 patients (21-80 y) with widely differing levels of renal function. We administered the drug in a single oral dose of 50 mg and collected blood and urine samples for up to 48 h after dosing. The plasma and urine concentrations of SUN1165 were measured by HPLC. The kinetics of SUN1165 could be characterized as a one-compartment model. The peak plasma level of SUN1165 was reached at about 2-4 h after administration independently of renal function but its fall was apparently delayed in renal impairment. The steady state volume of distribution was 1.48 1/kg and the absorption rate constant 2.23 h -I 9 These variables did not alter in renal failure. The plasma protein binding of SUN1165 was 34 % and independent of the levels of renal function. The elimination half-life was 3.41 h in normal renal function and 5.69 h in mild renal failure (CLcr, 5080 ml/min). It was prolonged to 9.28 h in moderate renal failure (CLcr, 20-50 ml/min) and to 23.67 h in severe renal failure (CLcr, below 20 ml/min). Cumulative urinary excretion and renal clearance were correspondingly reduced in patients with impaired renal function. Approximately 65 % of SUN1165 was eliminated via the kidney, by either glomerular filtration or tubular secretion. Non-renal modes of excretion showed no compensatory increase in patients with renal failure. There were significant correlations between CLcr and the kinetic parameters plasma elimination half-life, AUC, total body clearance and renal clearance of SUN1165. Our findings lead us to conclude that normal doses of SUNl165 can be given to patients with mild renal failure. However, the dosage should be reduced in patients with moderate and severe renal failure. First Department of Internal Medicine, School of Medicine, Kanazawa University, 13-I Takaramashi, Kanszawa, 920 Japan

PHARMACOKINETICS OF TILISOLOL IN HYPERTENSIVE PATIENTS WITH NORMAL OR IMPAIRED RENAL FUNCTION K.Sugimoto, H.$hicnoiri, K.Minamisawa, Y.Abe, S.Ueda_, A.Ikeda, H.Shimizu, E.Gotoh and M.Ishii The pharmacokinetics of tilisolol, a newly developed long acting 8-adrenoceptor blocking agent, was investigated in i0 hypertensive patients, five with normal renal function (NRF group) and five with mild renal impairement (IRF group). A 20 mg of tilisolol was administered orally, once daily for one week. Measurements of blood pressure and heart rate, and blood sampling for determination of plasma drug level and plasma renin activity (PRA) were performed on the day of initial and final administration. In NRF group, plasma drug levels or pharmacokinetic data were not significantly different between the initial and repeated administration. The mean half lives of elimination following single dosing were 8.4hr in NRF group and 9.1hr in IRF group. After repeated dosing, the elimination half life increased from 9.1br to ll.7hr in IRF group (p
PP 01.28

PP 01.30

HEMODYNAMIC EFFECTS AND KINETICS OF NITRENDIPlNE IN PATIENTS WITH RENAL FAILURE T. Ankermann, U. O s t e r k a m p , S.R. S a n t o s , W. K i r c h Nitrendipine i s a new d i h y d r o p y r i d i n e derivative which i s m a i n l y e x c r e t e d a f t e r b i o t r a n s f o r m a t i o n by the l i v e r . Consecutively a delayed eliminat i o n o f t h i s drug i n p a t i e n t s w i t h c h r o n i c l i v e r d i s e a s e has been shown ( ! ) . Eight hypertensive p a t i e n t s w i t h normal r e n a l f u n c t i o n (median creatinine c l e a r a n c e 94.5 + 6 . 8 m l / m i n ; X + SEM) and e i g h t a g e - and w e i g h t matched p a t i e n t s - w i t h chronic renal insufficiency (median c r e a t i n i n e c l e a r a n c e 27.2 + 11.5 m l / m i n ) were t r e a t e d o r a l l y f o r one w e e k - e a c h w i t h n i t r e n d i p i n e 20 mg o.i.d. Nitrendipine plasma c o n c e n t r a t i o n s were e s t i m a t e d by ~ gas c h r o m a t o g r a p h i c method. AUG 0-24 h of nitrendipine was s i g n i f i c a n t l y increased f r o m 9 7 . 8 + 1814 n g . m l - -h in the normals to 196.0 ~ 4 2 . 7 ngTml- .h in r e n a l p a t i e n t s . Corresponding elimination half-lives were 4 . 4 + 0 . 3 and 13.5 + 4 . 7 h. A marked i n c r e a s e in t h e distribution volume o f n i t r e n d i p i n e was seen in renal patients. P r o t e i n b i n d i n g o f the drug d i d not differ between b o t h g r o u p s . D e s p i t e accumulation of nitrendipine in r e n a l f a i l u r e the antihypertensive activity of nitrendipine was n o t enhanced compared w i t h the v a l u e s o f s u b j e c t s w i t h normal r e n a l f u n c t i o n .

PHARMACOKINETICS OF CELIPROLOL ENANTIOMEI~ IN HEALTHY VOLUNTEERS AND PATIENTS WITH RENAL PAILURE C. Hartmann, D. KrauB, H. Spahn, M. Fr~lich*, H. Kuauf* and E. Mntschler Previous radioligand-binding studies showed that the enantiomers of the ~l-selective adrenergie antagonist celiprolol have different pharmacodynamic properties (Wolff et al., Br. J. Clin. Praet., 39, Suppl. 40, 5, 1985). Therefore, evaluation of the pharmacokinetics of the two enantiomers is also necessary. The kinetics of R- and S-celiprolol were studied after oral administration of 200mg (R,S)-celiprolol-HCl in 8 healthy volunteers and in 8 patients with impaired renal function of different degrees of severity. Celiprolol enantiomers in plasma and urine were quantified after a two-step liquid-liquid extraction and HPLC on a chiral stationary phase ~Chiralcel OD) with n-hexane/ethunol/ diethylamine as mobile phase by nuorimetric detection. Neither in the control group nor in the patients differences between the two enantiomers could be found. In patients with significantly reduced endogenous creatinine clearance, the plasma concentrations of both enantiomers were higher than in the control group. Thus the average of the AUG in patients with renal impairment exceeded the average of the AUC values in healthy controls. The total amounts of celiprolol enantiomers excreted in urine were lower in patients with renal failure. The renal clearance was reduced in most of the patients, if compared to the controls. However, the terminal half-life was in a similary range for both groups. Pharmakologisches Institnt rtir Naturwissenschaftler der Johann Wolfgang Goethe-Uaiversit~t, Theodur-Stern-Kai 7, Geb~iude 75 A, D-6000 Frankfurt am Main 70 *St. Bernward-Krankenhaus, Treibestr. ?, 3200 Hildesheim

1) D y l e w i c z , P., K i r c h , W., S a n t o s , S . R . , H u t t , H . J . , M~nig, H., Ohnhaus, E.E. ( 1 9 8 7 ) B i o a v a i l ability and e l i m i n a t i o n of nitrendipine in l i v e r d i s e a s e . Eur J C l i n Pharmacol 32: 5 6 3 - 5 6 8 . I. Medizinische Klinik, Christian-AlbrechtsUniversit~t, Schittenhelmstrasse 12, D-2300 K i e l

A 129

PP 01.31

PP 01.33

EFFECTS OF AMOSULALOL IN PATIENTS WITH IMPAIRED RENAL FUNCTION

PHARMACOKINETICS OF REMOXIPRIDE, A NEW ANTIPSYCHOTIC, PATIENTS WITH VARYING DEGREES OF RENAL IMPAIRMENT

Miyazaki Mitsuhiro, Ohba Shoji(2), Narita Mitsuharu(3), Hayashi Kunihiko(4). Department of Internal Medicine, Mito General Hospital, Hitachi Ltd., Ibaraki, Japan, (2)Mito Central Hospital, Ibaraki, Japan, ( 3 ) I n s t i t u t e of C l i n i cal Medicine, University of Tsukuba, Ibaraki, Japan, (4) Department of C l i n i c a l Development, Yamanouchi Pharmaceutical Co. Ltd., Tokyo, Japan Amosulalol is a new drug that exerts selectivepostsynapic alpha and nonselective beta adrenoceptor antagonist in a r a t i o (alpha/beta blockade) of approximately 1:1. The effects of amosulalol on blood pressure and renal function (Ccr)were studied in 15 patients with impaired renal function (Ccc<80ml/min). The patients wereadmitted and placed on a standard diet containing 7g of sodium and were observed for 2 weeks. They received 10-20mg of amosulalol o r a l l y every 12hours for 8weeks. During this treatment period, s y s t o l i c and d i a s t o l i c blood pressure s i g n i f i c a n t reduced without increase in heart rate. Creatinine clearance(Ccr) was increased from 48.Sml/min to 54.2ml/min. Serum creatinine l e v e l , blood urea nitrogen (BUN), plasma renin a c t i v i t y ( P R A ) , plasma aldosterone concentration(PAC) and serum e l e c t r o l y t s level were unchanged. There were no remarkable changes in urine volume, body weihgt and cardiothoracic r a t i o . The pharmacokinetic study of amosulalol was carried out in other 10 patients with end-stage renal f a i l u r e (Ccr
IN

G. Movin~ J. Boelaert, L. Nilsson, J. Ohrvik

Remoxipride is a selective dopamine D2-receptor antagonist. Methods. The pharmacoklnetlcs of remoxipride 100 mg given orally was studied in 21 patients divided into 3 groups of 7 accordlng2to their creatinlne clearance (Clcr in ml/min/1.73 ): group A with Clcr >65, group B with Clcr 25-50 and group C with Clcr <25. Unchanged remoxlprlde was assayed in blood, plasma and urine by HPLC

Results. (mean):

A

B

C

pa,

Clcr (ml/mln) Cmax (~mol/l)

89 5.5

41 7.7

11 9.3

*** **

tmax (h)

0.8

0.9

1.4

AUC (~mol.h/l) t89 (h) U-recovery (48h) (%) ~l-acid glycoprotein (g/l)

39 5.1 24 0.8

63 6.1 14 1.3

123 9.9 8 1.7

** ** *** **

fu b)

0.21

0.17

0.14

*

AUCu c) (~mol.h/l)

8.6

10.3

15.8

*

a) C v e r s u s A (* p< .05, ** p~ .01), *** p< .001) b) f r a c t i o n unbound c) AUC unbound Conclusion. As the pharmacokinetics of unchanged remoxipride are s i g n i f i c a n t l y a f f e c t e d in p a t i e n t s w ith s e v e r e l y decreased renal f u n c t i o n (C l c r <25 ml/min), i n i t i a l t r e a t m e n t should be h a l f the normal dose with subsequent adjustments r e l a t e d to the c l i n i c a l e f f e c t . Dept. of Nephrology, Algemeen Ziekenhuis St.-Jan, Brugge, Belgium; Astra Research Centre SSdert~lje, Sweden.

PP 01.32

PP 01.34

PHARMACOKINETICS AND EFFICACY OF DOXAZOSIN DURING CHRONIC DOSING IN RENAL IMPAIRMENT D.C. Waller, R.M. Oliver, G. Dewhurst and A.G. Renwick Doxazosin is a selective ~l-adrenoeeptor antagonist with antihypertensive actions which is eliminated mainly by hepatic metabolism. This study has examined the effect of impaired renal function on doxazosin pharmaeokinetics during chronic once daily dosing. Eighteen hypertensive patients with diastolic blood pressure (BP) between 95 and 115 mmHg and glomerular filtration rates (GFR's) ranging between 13 and 127 ml/min participated after two weeks of placebo run-in. Doxazosin was given as sole therapy or added to treatment with a H-blocker or diuretic. BP and plasma drug concentrations were measured for 24 hours after an initial dose of 1 mg. Dose titration (maximum 16 mg) was then carried out at two week intervals. After one month of treatment at the highest dosage (median 8 mg), BP's and plasma concentrations were measured for 48 hours after the final dose. GFR and effective renal plasma flow (ERPF) were measured before and during long-term therapy with doxazosin, One patient withdrew from chronic dosing due to unwanted effects. BP 24 hours after the last dose of doxazosin had fallen by an average of 12/6 mmHg compared to placebo run-in. GFR and ERPF were unchanged after longterm treatment. Doxazosin plasma elimination half life (th) was 13.3 (4.9 SD) hours and mean residence time (MRT) 19.9 (7.4) hours after the first dose; these were not prolonged by renal impairment. Neither th nor the MRT were affected by chronic oral dosing at any level of renal function. Dose-adjusted AUC was similar during acute and chronic dosing. Doxazosin reduces BP during chronic oral dosing without adverse effect on renal function. Doxazosin does not accumulate during longterm dosing even in patients with marked renal impairment. Clinical Pharmacology Group, Centre Block, Southampton General Hospital, Southampton S09 4XY, U.K.

PRE DOSE LEVELS OF XIMOPROFEN AND OF ITS METABOLITES IN LONG TERM ADMINISTRATION IN RHEUMATIC PATIENTS WITH RENAL IMPAIRMENT. F.BONNET,G.DORF B.AUVINET,J.PAQUET,R.CAPORAL,B.LAFFEZ, LF.CHASSEAUD Ximoprofen, 2- (4 (3- oximinocyclohexyl) phenyl)propionic acid, is a new non-steroidal anti-inflammatory active at SO mg per day. Ximoprofsn was characterised as a drug of almost complete systemic availability (92%). After oral doses, Ximoprofen was rapidly absorbed with a t~ (abs.) of ca.20 min. Ximeprofen was primariiy eliminated by metabolism (keto and hydroxy-ximoprofen : two pharmacologically active metabolites) ; only 20% of the dose was excreted as the unchanged drug in the urine. The terminal halflifes of ximoprofen and keto-ximoprofen were 1.8 h and 2.1 h respectively. One repeated dose study in healthy subjects (15 mg at 12 hour intervals) has shown that the pharmacokinebies of ximoprofen was not altered and there was no notable accumulation of ximoprofen. This study used ten patients belonging to a long term tolerance study. The patients (2 men, 8 women) ware aged between 67 and 84 years and weighed between AS.5 and 78 kg. Their calculated ereatinine clearances ranged from 32 to 68 ml/min. The patients were treated with ximoprofen (SO mg/day) at least for 6 months.The blood samples were taken from fasting patients immediately before a dose of ximoprofen. Ximeprofen and its metabolites in plasma were analysed by capillary column gas-liquid chromatography with electron capture detection. Concentrations (Cmin) of ximoprofen, keto-ximoprofen and hydroxy-ximoprofen measured in the plasma of these patients were 0.25 • O.SO ~g/ml, 0.4a • 0.20 ~g/ml and O.SO • 0.i$ ~g/ml respectively. These concentrations were similar to those found in a previous repeated dose study. This study shows that there is no accumulation of ximoprofen and its metabolites in plasma of long-term treated patients whose creatinine clearances are lowered. Research Centre, J. LOGEAIS, Trappes, France

A 130

PP 01.35

PP 01.37

MEXILETINE IN ENDSTAGE RENAL INSUFFICIENCY AND

EFFECT OF RENAL FUNCTION AND D I A L Y S I S ON SZNGL.EDOSE PHARMACOKINETICS OF PIRMENOL ( C I . - 8 4 5 ) ,

DIALYSIS and W. Messer

3. E v s r s

We m o n i t o r e d 20 d i a l y s i s miss

patients

after r e p e a t e d

elimination

Levels

E,__Ja_Ei~_~.e_.~.~_H_~N__,.Bgg_h!~E.a..~.e..~:.~_.I.,_~b.s_p..g=.

the plasma

levels

With

of m e x i l e t i n a

After repeatsd

levels

range from 5 0 0 - 2 0 0 0

ng/ml.

arrhythand the

and dialysate

liquid were

in

procedures.

in p l a s m a

administration

trough

cardiac

administration,

dialysis

a~sayad by h i g h - p r e s s u r e 600 m g / d a y

severe

oral

by v a r i o u s

of m e x i l e t i n e

we~

chromatography.

of m e x i l e t i n e

400-

in the t h e r a p e u t i c

Traatmsnt

controlled

by l o n g - t e r m - e l e c t r o c a r d i o g r a p h y was s f f e c t i v e in 13/20 patients. Doses more than 600 mg/d often ware not t o l e r a t e d ter some weeks.

of m e x i l e t i n e hemofiltration,

by p a t i e n t s

There

with

dialysis

was no i m p o r t a n t

from plasma

during

af-

nor p l a s m a -

In c o n c l u s i o n

we r e c o m m e n d

dosage of 4 0 0 - 6 0 0 ciency Mad.

a slightly

mg m e x i l e t i n e / d a y

for p a t i e n t s irrespective

Klinik

Renal cLearance accounts ~:or o n L y a b o u t 2 0 Z ot: p~rmemo.L c l e a r a n c e i n G r o u p A~ i n d J c a t i r l g that decreased rena(, c l e a r a n c e a l o n e c a n mot e x p l a i n t h e 3& and 6t:~{ d e c r e a s e s i n C L / F i n G r o u p s B and

avaiLabLe f o r nen.sL e x c r e t i o n probLabLy corrt;ributed to the decrease in p~rmenoL

pharesiso

800 mg)

fs an e• class fa a n t i arrhythmi F agent. 3 g~"oups (A,B,C:[ 0s 7 subjec:ts e~:4ch, with cr'eatinine c l e a r a n c e s (CLcr) oE >70 (A), 30--70 (B)~ and 10.-30 (C) m L / m i n / i . 7 3 m 2 ~ received a s i n g L e 20C-rag dose el pJrmemoL. PLasma and ur'ine s a m p L e s were assayed ~orp ~ v m e n o L by HPL.C. PLsBma.~ aLpha-'l-acid g L y c o p r o t e i n (AG) was m e a s u r e d by radial ~mmurlodi//usion. PirmenoL plasma p r o t e ~ n b ~ n d i n g was d e t e r m i n e d by e q u i l i b r i u m d i a l y s i s using p v e d o s e plasma spiked with 14C-.pirmenoL. blean total p'irmenoL plasma clearance (CL/F) v a l u e s were ":~40 irl A, 89.7 ~n B and 54 mL/m~n in C.

C, respec:tiveLy, relative to Group A. Hos.,ever~ p i r m e n o L plasma p~'otein bindirl.g w,as e l e v a t e d in Groups B and C due to increased AG aonc:entret~ons in pLa.sm,.~. There.Eore, Less u n b o u n d drug

removal

hsmodialysis,

peritonealdlalysis

Pirmenot

with e n d a t a g e

reduced

(usually renal

600-

insuffi-

of dialysis.

I, O s t m s r h e i m e r s t r .

200, D-5 KSln

91

CL/F

observed in renal dys~unc'tion. In addition, s~mce pirmenoL has a Low h e p a t i c e • ratio,inc:reased p r o t e i n b i n d i n g may have dec:re .... ased pirmeno[ h e p a t i c clearance, r e d u c i n g CL/F. 7 s u b j e c t s underwent 4.5 hours o; hemodiaLys'is / o / L o w i n g a 200 mg oral dose o{ p ~ m e n o L . A p p r o x i m a t e L y 2% o~ the dome was recovered 'in the d~aLysate. D i a L y s i s ~s not an e f f e c t i v e means of removing pirmenoL ~rom the b o d y . Renal Unit, A t g e m e e n Z i e k e m h u J s St-Jan, 8000 BrQgge,

Be Lgiu~n.

PP 01.36

PP 01.38

PHARMACOKINETICS OF CIPROFLOXACIN IN PATIENTS WITH RENAL IMPAIRMENT AND ON DIALYSIS N.J.Deuber,G.Ohrisch,W.Schulz,O.Hop~,G.BScker Due to predominant renal excretion of ciprofloxacin(cip) in renal insufficiency a dose adaptation is necessary. Aim of this study was to determine appropiate dosages in renal insufficient patients with and without dialysis. 35 patients with different stages of renal insufficiency were treated with either 200mg iv or 500mg orally cip once to twice daily during 5 days,followed by a wash-out period of 3 days. Blood samples were taken throughout each day to obtain kinetic data. Tissue samples were taken additionally. Cip and metabolite concentrations were measured by HPLC. half life creatinine(mg/dl) ciprofloxacin metabolite below 8 6h over 8,non dialysis 21-14h 11h hemodialysis 7h 12h Tissue concentrations were 1.3+0.6mg/1.A single hemodialysis removes approximately 20mg of tip, a ~ingle peritoneal dialysis removes 0.2mg of cip. Plasma concentrations of cip after and before hemodialysis differ by 30-50%.Clearances of cip are approximately 60ml/min,regardless of dialyzer used. In patients without or with moderate renal impairment and in patients on hemodialysis it is recommended to apply 2OOmg dip iv or 500mg tip orally twice a day. If serum creatinine is higher than 8mg/dl it is sufficient to apply 200mg cip iv or 500mg cip orally once a day.

PHARMACOKINgrICS OF C~'fRIA3[ONE IN PATIENTS WITH RENAL FAILURE ON HHMOFILIRATION. T.Y. Ti~ H.S. Lee and E.J.C. Lee The pharmacokinetic disposition and protein binding of ceftriaxone were studied in 3 renal failure patients undergoing hemofiltration. Arterial blood samples Were obtained (at the input of the filter) before ceftriaxone infusion and st I0, 30 min, l, 2, 3, 4, 6, 12 h post drug infusion. The filtrate was also collected for drug assay. The ceftriaxone assay was performed bikAion-pair reversed phase HPLC. T h e Amicon Centrifree ultrafiltration devices were used for the protein binding studies.

III.Med. Elinik,Klinikum Bamberg,und Nephrologie und Osteologie,Bamberg, Buger StraBe 80,D.8600 Bamberg,PRG

Institut

f~r

TM

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Patient Age (years) Study Dose (mg) Hemofilter

A 65 Single dose 500/24h Gambr~174 (FB55)

B C 55 77 Multi-dose Multi-dose 500/24h lO00/12h Gambro| Ultraflux AY (FH55) (FRESENIUS AG)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cmax (mg/L) t~B (hr) Vc (L) Vss (L) AUCpgh/ml C1 T (ml/h) Clhe m (ml/b) ~lhem (%) CI T Mean Protein Binding %

91.7 38.8 5.44 13.48 2032 246 136 55.3

209.6 63 5.0 14.85 3018 165.7 109 65.8

307 27 9.34 13,5 2851 350.7 322 91.8

30•

12.4•

21.2•

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The study in the 3 patients showed that the beta half-life of ceftriaxone was prolonged and there was significant clearance of the drug by hemofiltration. This may in part be due to the low albumin binding of 12.4 - 30%as compared to 95% in the healthy person. Department of Pharmacology, National University of Singapore, iOKent Ridge Crescent, Singapore 0511.

A 131

PP 01.39

PP 01.41

E L I M I N A T I O N OF P H E N P R O C O U M O N A N D M E T A B O L I T E S IN P A T I E N T S ON M A I N T A I N A N C E H E M O D I A L Y S I S J ~ B o m m e r .......U..: V ~ I k e r ........J.X. ... de V r i e s ........~.G u t z l e r

PHAI~4ACOKINETIC CONSIDERATIONS ON DRUG THERAPY IN COh[flNUOUSAMBULATORY PERITONEAL DIALYSIS (C.A.P.D.). N. Lame• Renal Division, University Hospital, De Pintelaan, 185, 9000 GENT.

C l i n i c a l o b s e r v a t i o n s in p a t i e n t s w h o r e c e i v e d phenprocoumon (PH) for oral ant• during maintainance hemodia!ysis (HD) showed that stable prothrombine time (PT) v a l u e s w e r e d i f f i c u l t to a c h i e v e . We t h e r e f o r e e x a m i n e d the plasma concentrations of PH as w e l l as its metabolites and their elimination in the hemodialysis fluid. 3 patients were investigated who required a mean daily PH-dose of 4.0 mg in account of cardiac disease; because of renal insufficiency they were d i a l y s e d for 4 - 5 h t h r e e times per week. The concentrations of PH a n d its m e t a b o l i t e e (7-, 6- and 4 ' - O H - P H ) in p l a s m a and d i a l y s a t e w e r e determined by HPLC and GC-MS; they remained nearly constant during one d i a l y s i s session. The p l a s m a p a t t e r n a n d c o n c e n t r a t i o n s of PH and metabolites were different from patients without renal failure. The e l i m i n a t i o n of PH and metabolites in the hemodialysate was e s t i m a t e d as 17 % of the m e a n P H - d o s e p e r week. Thus PH and metabolites are eliminated s i g n i f i c a n t l y in the d i a l y s a t e d u r i n g d i a l y s i s , although PH is b o u n d v e r y s t r o n g l y to p l a s m a proteins. The unbound fraction (fu) of PH d e c r e a s e d d u r i n g d i a l y s i s f r o m 0,84 % to 0,44 % ( h e a l t h y s u b j e c t s 0,30 %) . The d e c r e a s e of PH fu in p l a s m a d u r i n g h e m c d i a l y s i s indicated e l o w e r free d r u g c o n c e n t r a t i o n at the end of the dialysis, These factors could be in part responsible for the d i f f i c u l t i e s in a t t a i n i n g s t a b l e PT v a l u e s in d i e l y s e d p a t i e n t s w h o w e r e t r e a t e d w i t h PH. M e d i z i n i s c h e K l i n i k d e r Universitfit H e i d e l b e r g , Bergheimer Str. 58, D 6900 H e i d e l b e r g , FRG

C_APD has become widely accepted as treatment for terminal renal failure. In this technique, 2 L of dialysate are instilled in the peritoneal cavity, usually 4 times per 24 hours. The need for adjustment of drug dosage in uremic patients on h a ~ i a l y s i s is well recognised. Also in CAPD, numerous pharmacokinetic studies after systemic administration of drugs have been performed. The question arises whether such studies are worthwhile toperform. The elimination of CAPD for drugs is mainly limited to the low dialysate flow rate, which is 6 to 7 ml/min. Peritoneal drug clearances can never exceed these values. In addition, an unfavorable ratio of the 2 L dialysate volu~ae to the body volume of distribution, the low ratio of peritoneal to body clearance and the effects of plasma drug protein binding further limit the transperitoneal drug transport. After intraperitoneal (IP) administration, the described apparent unidirectional peritone~n to blood drug transport is mainly explained by the large differences in the body distribution volumes to the peritoneal cavity. This results in a rapid disappearance of a drug from the peritoneal cavity due to the high concentration gradient across the peritoneal membrane. Studies performed by us and others have shown a faster peritoneal drug transfer during peritonitis for gentamycin, tobramycin and cefuroxime. In conclusion, after syste~nic drug application in CAPD, drug dosage adaptations for CAPD are almost never necessary and formal pharmacokinetic studies should not be performed in this setting. In contrast, after IP admlinistration, careful studies should be performed to avoid toxic accumulation of certain drugs in the blood.

PP 01.40

PP 01.42

THE PHARMACOKINETICSOF DESFERRIOXAMINEAND ITS CHELATED COMPOUNDSFERRIOXAMINE(FO) AND ALUMINOXAMINEIN DIALYSIS PATIENTS. p,c. D'Haese. G.A. Vernooten. L.V. Lamberts. J. Boelaert ~. I. Becaus**L M.E. De Broe. Chelation therapy with DFO is the treatment of choice for severe iron and aluminum overload in dialysis patients. An indirect atomic absorption method was developed allowing the determination of unchelated DFO as well as FO and AlO by selective extraction from the accompanying matrix. Total DFO concentration was calculated as the sum of unchelated DFO, FO, and AID. Patients were selected according to the presence of l i v e r disease (LD) and/or hemosiderosis (HS).

PHARMACOKINETICS OF NETILMICIN DURING PERITONEAL DIALYSIS S.G.Shin, C.W. Park and K.S.Kim To analysis transport of netilmiein through peritoneum and establish appropriate dosage guideline in CAPD patients with peritonitis, we studied pharmacokinetics of netilmicin in 8 patients undergoing CAPD for chronic renal failure. 100mg single loading or 20mg maintenance dose was administered to these patients through dialysis fluid. Netilmicin concentrations of serum and dialysis fluid were measured by fluorescence polarzing in~runoassay, and the data were subjected to computer analysis using two compartment model which considered the bidirectional flux of the drug. Distributional clearance of plasma to dialysis fluid (CI d) , clearance of dialysis fluid to plasma(Cldp) andPmean dialysis clearance(CID) were 5.99~2.83, 11.56 +3.43 and 3.59+1.41 ml/hr/kg, respectively. Volume of distribution o~ netilmicin in tbese patients was 0.34 +0.12 L/kg and body clearance(Cls) was 6.81+2.90 ml/hr/kg. Estimated half-life of netilmicin during end stage renal disease reduced from 39.7 to 23.6 hours by CAPD. Simulated mean steady-state peak and trough netilmicin concentrations after 20mg maintenance dose administration per 6 hours were 5.4 and 5.2 ug/ml, respectively. Pharmacokinetic data obtained from this study can be used for optimum loading and maintenance dose design of netilmicin in patients who have peritonitis during CAPD. Clinical Pharmacology Unit, SNU Hospital and Department of Pharmacology, College of Medicine, Seoul National University, 28 Yeongun-dong, Chongro-gu, Seoul, Ii0 Korea

GROUP N LD HS

I* II III IV

TOTA~DFO T~ min

5 125• 5 704• 10 - +I 940• 5 + +I 1514•

FO T89 min 256• 961• 1773• 2607•

peak umol/L 5.9• 9.7• 29.1• 33.2•

*normal renal function; **Kruskal-Wallis: p
A 132

PP 01.43

PP 01.45

BUSPIRONE MULTIPLE DOSE PHARMACOKINETICS IN RENAL AND HEPATIC IMPAIRMENT K.A. Pittman, U.A. Shukla, M. Pfeffer, E. Morsenthien, R.H. Barbhaiya, H. Saby, J. Duchier and B. Flouvat. Buspirone, a new drug for the treatment of generalized anxiety disorder, is rapidly absorbed, undergoes extensive first-pass metabolism, and is eliminated with a half-life of 2-4 h following oral administration. Plasma concentrations of l-pyrimidinylpiperazine (I-PP), the major psychoactive metabolite are higher than buspirone. This study assessed the tolerance and pharmacokinetics of 20 mg/day (i0 mg b.l.d.) buspirone for i0 days in 12 normal volunteers, 17 renally impaired (6 mild, 5 moderate and 6 severe) patients and 12 cirrhotic (6 compensated, 6 decompensated) patients. Serial plasma samples and total urine output was collected on days 1,5 and i0 following buspirone doses. The samples were assayed for buspirone and I-PP by GC-MS. Buspirone was well tolerated in all groups. Steady-state was evident by day 5 for both buspirone and I-PP. At steady-state, buspirone Cmax and AUC were significantly higher in renally and hepatically impaired patients than normal subjects. Hepatieally impaired patients had significantly longer buspirone half-life than normal subjects. The effects were greatest in decompensated liver disease. Traces of buspirone (<1% of dose) were excreted in the urine, with the greatest amounts in decompensated liver disease. For I-PP only severely renally impaired patients had significantly higher AUC than normal subjects. A significant correlat%on (r = 0.678, P = 0.003) between the log of buspirone oral clearance and Bromsulphalein clearance coefficient was observed. A significant correlation (r = 0.476, P = 0.009) between the log of I-PP AUC normalized for dose and creatinine clearance was also observed. Dosage adjustment for buspirone is indicated for both renally and hepatically impaired patients.

PHARMACOKINETIC STUDY OF LANSOPRAZOLE IN HEALTHY SUBJECTS AND IN PATIENTS WITH LIVER DISEASES. B. Delhotal-Landes, G. Miscoria, A. Cournot, J. Duchier, J. Larcheveque and B. Flouvat. Lansoprazole (AG 1749 Takeda) (L) is a new proton pump i n h i b i t o r in the gastric mucosa. I t is extensively biotransformed in man, mainly by oxidative mechanism to several metabolites : the sulfone (AG 1813 or M1), the sulfide (AG 1777 or M2) and the hydroxy metabolite (AG 1908 or M3). In this study, we have determined the pharmacokinetic prof i l e of L and i t s metabolites a f t e r a single 30 mg oral dose (enteric coated granules in capsule) in fasting subjects. Thirty subjects, between 22 to 65 years of age, part i c i p a t e d to the study : six healthy volunteers (three men three women), eigth patients with acute h e p a t i t i s and s i x teen patients with cirrhosis of the l i v e r , the half in uncompensated state. Blood samples were drawn during 48h after dosing. Plasma concentrations of L and i t s three metabolites were measured by high performance l i q u i d chromatography with a l i m i t of detection of 2 ng/ml. In a l l patients, an increase of M1 and M2 plasma levels was observed, but in hepatitis the M2 increase was higher than in cirrhosis. The hydroxylated metabolite (M3) plasma levels were strongly decreased in a l l patients. The L absorption rate was not modified but the L plasma h a l f - l i v e s were longer (mean 7.Oh), exceeded 10 h in some patients, than in healthy subjects (mean 2.Oh). The L and nonhydroxylated metabolites (M1 and M2) plasma AUC were s i g n i f i cantly increased (pC0.05). This study shows that l i v e r diseases a l t e r lansoprazole pharmacokinetics and i t s rate of metabolism. Toxicological and Pharmacokinetic laboratory, A. Par~ Hosp i t a l , 9 avenue Charles de Gaulle, 92100 BOULOGNE, THERAPHARM Paris and HOUDElaboratories, 92 PARIS LA DEFENSE, FRANCE.

PP 01.44

PP 01.46

M E T I P R A N O L O L K I N E T I C S A N D D Y N A M I C S IN P A T I E N T S WITH LIVER CIRRHOSIS AND HEALTHY SUBJECTS

INFLUENCE OF LIVER CIRRHOSIS ON THE PHARMACOKINETICS OF REMOXIPRIDE, A N0VELANTIPSYCHOTIC DRUG

F. P e r l i k , Janku

M. T k a c z y k o v a ,

M.Brodanova

a n d I.

Disposition kinetics of the beta blocking agent metipranolol has been compared in healthy subjects and in p a t i e n t s w i t h h i s t o logically proven liver cirrhosis after a s i n g l e 40 m g oral dose. P l a s m a m e t i p r a n o l o l concentrations were measured by high pressure liquid chromatography with electrochemic d e t e c t i o n u p to 12 h o u r s a f t e r t h e d r u g a d m i nistration. No statistically significant differences between both groups were obtained in m e t i p r a n o l o l p l a s m a c o n c e n t r a t i o n s as w e l l as in e s t i m a t e s of p h a r m a c o k i n e t i c p a r a m e t e r s . Beta-blockade was assessed by measuring heart rate and again no m a r k e d d i f f e r e n c e s w:ere detected in t h e m e t i p r a n o l o l e f f e c t in b o t h groups. However, the concentration-effect relationships revealed that there is no clearcut correlation between the beta-blocking effect and the metipranolol c o n c e n t r a t i o n in plasma: in t h e majority of subjects the m a x i m u m of b e t a - b l o c k a d e occurred during the decline of metipranolol concentration in plasma. Is~ Department of Medicine, Faculty of M e d i c i n e ; S t a t e I n s t i t u t e for C o n t r o l of Drug; Institute of Pharmacology, Czechoslovak Academy of Sciences, U nemocnice 2, 128 08 P r a g u e 2, C z e c h o s l o v a k i a

K.-G. Jostell, R. 01sson~ A. He$~elund, G. Movin, L. Nilsson~ J. Ohrvik Remoxlpride is a selective dopamine D2-receptor antagonist belonging to the benzamide group.

Methods: The pharmacokinetics of remoxlpride was studied after a single i00 mg oral dose in i0 patients with mild to moderate liver cirrhosis and in 10 age- and sexmatched control subjects. Blood, plasma and urine was sampled during 48 hrs and assayed for remoxlpride by use of HPLC. Results: Mean pharmacokinetic variables of remoxiprlde Cmax tmax AUC t~ fu AUCu Ae CLRu ~mol/l

h

~mol 9h/l

h

~mol .h/l

Z

ml/min /1.73m 2

Cirr.

3.75

1.35

40.0

7.6

0.26

9.44

38

152

Contr.

4.69

1.15

41.0

5.9

0.20

8.17

30

137

P-value N.S.

N.S.

N.S.

N.S. <0.038

N.S.

N.S.

N.S.

The free fraction ( f ) of remoxipride in plasma was increased in the patients, associated with a disease related decrease of the major binding protein, ~1-acid glycoprorein. However, no siginlficant differenc~ in the areas under the unbound plasma concentration versus time curves (AUC) was found. Conclusion: Although no substantial changes in the pharmacokinetics of remoxipride were found in patiens with mild to moderate liver cirrhosis, an initial dose reduction is advisable, especially in patients with advanced stages of liver disease. Clinical Pharmacology, Astra Research Centre, S-151 85 S~dert~lje, Sweden.

A 133

PP 01.47

PP 01.49

EFFECT OF NIKET~DE ON HYDROXYLATING AND GLUCURONYL-CONJUGATING F U N C T I O N O F TH~ L I V E R I N HUNA/~S ~.I. Bushn~., L,B..Z~y.odnik, V..~. T s y r k u n o v , 2[~I. L u k i e n k o i L.F......Legonkova i V.S. V a s i ! y e v

MKTABfI-~M OF ~

I n h e a l t h y s u b j e c t s , the e f f e c t s of n i k e t h a m i de (250 mg, p e r os, 3 t i m e s a day e v e r 8 d~ys) o n the l i v e r h y d r o x y l a t i n g f u n c t i o n ( a c c o r d i n g to a n t l p y r i n e k i n e t i c s , p r o d u c t i o n r a t e a n d p r o f i l e of its m e t a b o l i t e s ) w e r e studied, whereas in patients with Jilbert's syndrome, t h o s e o n the g l u c u r o n y l - c o n j u g a t i n g function ( a c c o r d i n g to d e c r e a s e of b l o o d b i l i r u b i n a n d e x c r e t i o n of g l u c u r o n i d e s ) . I n the e x p e r i m e n t a l group, the h a l f - l i f e of a n t i p y r i n e (in s a l i v a ) w a s r e d u c e d b y 2 5 % a n d the u r i n a r y c o n c e n t r a t i o n s of 3 - c a r b o x y m e t h y l a n d n o r a n t l p y r i n e w e r e e l e v a t e d b y 349 a n d 1 @ 9 % o v e r 24 h. The i n c r e a s e d l e v e l s of the a n t i p y r i n e m e t a b o l i t e s c o r r e l a t e d w i t h the r a i s e d u r i n a r y c o n c e n t r a t i o n s of b o u n d g l u c u r o n i c acid. The i n t a k e of the drug b y p a t i e n t s w i t h decreased bilirubin-conjugating f u n c t i o n of the l i v e r r e d u c e d the b l o o d b i l i r u b i n f r o m 39.6 to 1 8 . 6 j u m o l / 1 . The t h e r a p e u t i c e f f e c t c o m p a r e d f a v o u r a b l y w i t h the a c t i o n of z i x o r y n , phenobarbltaland its combination with pyrogenal, I n s t i t u t e of B i o c h e m i s t r y , B y e l o r u s s i a n S S R A c a d e m y of S c i e n c e s , the L a b o r a t o r y of B i o c h e mical Pharmacology, 50 L e n i n K o m s o m o l Blvd., Grodnc, 2 3 0 0 0 9 , U S S R

I ~

]]i ( ~ I C

~

PAIN

C.C.Faura. D.Carroll. ~ R.A.Mo.qre, H.J.MeOuav. The contribution of the active metabolite merphine-6-glueuroside (M6G) to analgesic efficacy when patients take morphine (M) has yet to be quantified. After a single dose of M the ratio of M6G to M is 3:1; this study was designed to determine the relationship between plasma M and dose, the M6G:M ratio with chronic oral dosing, and sources of variability. Blood samples were taken from patients taking morphine. Details of the patient's age and sex were recorded, together with, details of other drugs and the dose and duration of morphine prescription. M was measured using DPC serum morphine kit, M3G & M6G by differential RIA. The mean, median & range for 131 patients are shown in the table: Wean

Median

Range

Age (yr) 63.83 63 28 - 92 Dose prev.24hr (rag) 225.58 90 0 - 2540 Plasma Concentration (omol/L) Morphine 272.67 121 1.80 - 3497 M3G 6386.18 3853.40 40.60 - 51066 M6G 1385.68 494.26 9.90 - 10970 Ratio ~G:Morphine 30.78 27.80 0.84 - 87.95 Ratio M6G:Morphine 6.17 5.22 0.29 - 19.38 The expected relationship between morphine dose and plasma concentration was significant (r = 0.656), the concentration rising as dose increased. There was wide variation in the extent of metabolite production, both of M3G and of M6G, but there was no evidence that dose affected metabolism. However, the importance of renal function was underlined by significant differences (p<0.01) in the M3G:M end M6G:M ratios between those patients with normsl pla~a creatinine and those with raised levels (>120)imol/L). It seems likely that M6G is responsible for a considerable part of the analgesia felt or observed after a dose of morphine, but the extent of metabolism varies widely, and currently there are no predictors for the variation. Renal function is one factor implicated in this variability; quantification may improve treatment efficacy. Nuffiald Dopt. of Anaesthetics, John Radcliffe Hospital, Oxford OX3 9DU and DPC-ERI, Witney. U.K.

PP 01.48

PP 01.50

EFFECT OF A TYPE OF G A S T R I C S U R G E R Y ON THE P H A R M A C O K I N E T I C S A N D P N ~ R M A C O D Y N A M I C S OF PROPRANOLOL.

MIDAZOLAM CONCENTRATIONS DURING INTRAVENOUS LIPID I N F U S I O N S FOR T O T A L P A R E N T E R A L N U T R I T I O N (TPN) IN S E V E R E L Y ILL PATIENTS

J.M. R o d r ~ g u e z - S a s i a i n , A. Valdivieso, E. Su~rez, J.P. Gonz~lez.

R. Calvo,

The i n f l u e n c e of several types of gastric s u r g e r y upon the a b s o r p t i o n of acidic drugs is well documented, but i n f o r m a t i o n about a b s o r p t i o n of basic drugs in this c o n d i t i o n is scarce. We have i n v e s t i g a t e d the d i g e s t i v e a b s o r p t i o n of a single dose of 80 mg of p r o p r a n o l o l (PR) in four surgical p a t i e n t s b e f o r e and, at least, three m o n t h s after e l e c t i v e v a g o t o m y and p y l o r o p l a s t y . U n c o n j u g a t e d drug c o n c e n t r a t i o n s after oral a d m i n i s t r a t i o n were m e a s u r e d by a HPLC t e c h n i q u e (G. N y g a r d et al. J. Pharm. sci. 68, 379, 1979], and drug effect was m o n i t o r e d w i t h an e l e c t r o c a r d i o g r a p h . 14 b l o o d samples were o b t a i n e d at regular intervals over 12 h. No s i g n i f i c a n t c h a n g e s were o b s e r v e d in p l a s m a p e a k free PR levels, before and after surgery (Cmax = 38.5 f 13.0 vs 29.5 • 5.1 ng.ml-l; P = N.S.). Paralelly, no changes in tma x were d e t e c t e d (2.5 h in both series). Drug effect, m e a s u r e d as QTc interval and frequency, was also similar before and after surgery, s u g g e s t i n g that a b s o r p t i o n of basic drugs does not seem to be a f f e c t e d by this kind of gastric surgery, as has p r e v i o u s l y been d e s c r i b e d i n v o l v i n g acidic drugs (R. C a l v o et al. Biopharm. Drug Dispos. 8, 115, 1987). Dpto. F a r m a c o l o g f a . Fac. Medicine. U n i v e r s i d a d del Pals Vasco. 48940 L e i o a (Vizcaya). Espa~a.

For e x c l u s i o n of a t e m p o r a r y t r a p p i n g of the h i g h l y l i p o p h i l i c c o m p o u n d m i d a z o l a m by p l a s m a lipids therapeutic drug concentrations and plasma lipoproteins were monitored in 8 p a t i e n t s r e q u i r i n g i n t r a v e n o u s lipid i n f u s i o n s for TPN. Blood s p e c i m e n s were o b t a i n e d d u r i n g continuous intravenous administration of midazolam necessary for sedation during artificial respiration; samples were drawn prior to, 2h and 6h after s t a r t i n g and 8h after c o m p l e t i o n of i n f u s i o n of a m i x e d m e d i u m chain triglyceride/long chain triglyceride (MCT/LCT) emulsion. M i d a z o l a m was m e a s u r e d in p l a s m a and in l i p o p r o t e i n f r a c t i o n s (obtained by u l t r a c e n t r i f u g a t i o n ) u s i n g a G C - m e t h o d (de Vries et al., Naunyn-Schmiedeberg's Arch. Pharmacol. 337, Suppl., R 123, 1988). D u r i n g nhe lipid i n f u s i o n total p l a s m a t r i g l y c e r i d e s and V L D L - t r i g l y c e r i d e s rose by more than 50% and 100% r e s p e c t i v e l y ; in contrast m i d a z o l a m c o n c e n t r a t i o n s in p l a s m a and the VLDL f r a c t i o n on average declined by 10-20% and 40-50% respectively. This indicates that m i d a z o l a m does not a c c u m u l a t e in the l i p i d phase of the blood during intravenous application of a M C T / L C T emulsion. A b t e i l u n g K l i n i s c h e P h a r m a k o l o g i e der Medizinischen Universit~tsklinik, B e r g h e i m e r Str. 58, D-6900 Heidelberg, FRG.

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PHARMACOKINETICS OF DILTIAZEM (DZ) IN PATIENTS UNDERGOING CARDIOPULMONARY BYPASS(CPB) SURGERY Y. K. Tam, B. A. Fineqan and B. Steward DZ is effective against coronary artery vasospasm (Fed. Proc. 40, 2877, 1981) and may protect ischemic myocardium from c a l c i u m induced damage during reperfusion ( A n n . Thorac. Surg., 42, 675, 1986). Therefore, the object of this study was to evaluate the pharmacokinetics of DZ during CPB. Sevenpatients (6 m; I f; age: 52 to 68 yr; weight: 74 to 97 kg) who underwent coronary artery bypass grafting were on 60 mg oral DZ t . i . d , or q.i.d, for at least three months prior to surgery. The total plasma DZ and its two metabolites, N-demethyl and deacetyl DZ, levels (mean • SEM) were 164 • 15, 31.4 • 4.5 and 64.7 • 6.8 ng/ml, respectively, before CPB. DZ concentration dropped to 47 • 1 % of the i n i t i a l value at the beginning of CPB (PO.05). DuringCPB, the levels o f all three species rose to maxima which were equivalent to 63 i 2, 116 • 3 and 162 i 18 % of pre CPB values. Similar levels were maintained within two hours after CPB. The free fraction of DZ in plasma was increased from 0.334 • 0.017 to 0.701 • 0.034 during CPB (PO.05). Twenty hours after the beginning of CPB, the free f r a c t i o n of DZ in plasma was 0.402 • 0.025 and free DZ level was 22 • 2 % of the pre CPB value. These results suggest that a change in d i s t r i b u t i o n and/or reduction in the disposition of DZ and i t s metabolites are responsible for the s l i g h t increase and decline of DZ and metabolite levels du~ing C P B . Therapeutic concentration of free DZ was maintained during and within two hours a f t e r CPB. Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta; Canada, T6G 2N8.

ACUTE AND CHRONIC PHARMACOKINETICS OF TOTAL ZOFENOPRILAT IN HYPERTENSIVE PATIENTS W.J. Louis, L.G. Howes. O.H. Drummer and H. Krum Pharmacokinetics of total 4-thiophenyl captopril (SQ 26,333) were determined following acute and chronic (3 week) administration of Zofenopril once daily at three dosage levels in 24 subjects. Preliminary analysis has been carried out in 6 subjects (7.5 nag), 5 subjects (15 rag) and 4 subjects (30 rag). Total SQ 26,333 was measured by radioimmunoassay using a specific antibody to 4-thidphenyl captopril-NEM with a detection limit of 2 ng/ml. Pharmacokinetic parameters varied between individuals and within individuals following both single doses and repeated administration. Following single-dose administration mean (+ S.E.) peak plasma concentrations of total SQ 26,333 were 280i-_181, 360-3:218 and 539+.r ng/ml for the 7.5, 15 and 30 mg doses respectively. These occurred at 1.2, 1.3 and 2.2 h, respectively. The corresponding AUCs (0-24 h) were 40(082, 1275+426 and 1913+808 ng.h/ml which were consistent with linear pharmacokinetics. The elimination half-life in plasma was estimated at 1-3 h. T-~ increased significantly with increasing dose (independent of duration of treatment) and also increased with chronic administration (independent of dose) (Two-way ANOVA). Following chronic treatment small amounts of total SQ 26,333 were detected in pre-dose plasma (7-25 ng/ml), however Cmax and AUC did not change significantly following chronic administration. Blood pressure was reduced for between 5 to 12 h following both acute and chronic zofenopril administration. University of Melbourne, Department of Medicine, Clinical Pharmacology & Therapeuics Unit, Austin and Repatriation Hospitals, Heidelberg, Victoria, Australia 3084.

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DOXAZOSIN PHARMACOKINETICS IN HYPERTENSIVE PATIENTS ~. Boutagy~ G.S. Stokes, H. Johnston, F. Rumble, J.Wood and G.M. Shenfield, Doxazosin (DOX)is anal-receptor antagonist. A study of the pharmacokinetics ~f oral DOX was conducted as part of a phase III trial in essential hypertension. 13 patients (mean age 57, range 36-68y) were administered a first dose of DOX, 2mg orally (acute study). Serial blood samples were collected pre-dose then at intervals to 8h, Patients were then seen weekly for 8 weeks and DOX dose adjusted to achieve a diastolic blood pressure of 90mmHg or less. The dosage of DOX ranged from l-8mg/day. During this period blood samples were collected 12h post-dose (steady state maintenance phase), i0 of the patients then had a repeat pharmacokinetic study (chronic study) with a single 2mg oral DOX dose and with the same sampling times as the original study. Plasma DOX concentrations were measured by a specific HFLC procedure with fluorescent detection. Results: Acute Study Chronic Study (n=13) (n=10) Baseline Conc.(ng/ml) 0 19.9• Cmax(ng/ml) 12.1+_4.5 34.9+_18.1 Tmax(h) 2.1• 2.0+__0.9 AUCo-Sh(b.ng/ml) 66.6+__20.4 214 _+120 Tl/2elim(h) 11.2+_13.81 12.0+7.1 Vd(1) 578 _+806 797 +__685 The 12h maintenance DOX plasma concentrations on the following doses were: Dose(mg) DOX Conc.(ng/ml) 1 5.4+_2.0 (n~24) 2 8.6+__3.3 (n=21) 4 22.6~13.1 (n=13) 8 53.9• The values show a trend for disproportionate increase in plasma concentrations with increasing dose. Further studies will be necessary to establish whether DOX has dose dependent kinetics. Dept. Clinical Pharamcology, Royal North Shore Hospital, St Leonards, NSW, 2065, Australia.

EFFECT OF H Y P E R L I P I D E N I A ON PHARMACOKINETICS OF P R O C A I N A N I D E / P / AND N - A C E T Y L P R O C A I N A M I D E / N A P A / B. Ga~ro~ska-Szklarz and J. W d ~ c i c k i ~he possibility that h # p e r l i p i ~ m i a - c o u l d influence the pharmacokinetics of various drugs is of practical importance in view of widespread ~vperlipidemia. The present study examines the pharmacokiuetics of P in rabbits with hyperlipidemia. The study was carried out on male rabbits randomly divided into 2 groups /all rabbits presented the fast acetylator phenotype/: group I was control, group 2 received a high-fat diet for 8 weeks. A f t e r that time lipids were assayed in the blood serum. P was administered orally as a single dose and measured by the f l u o r e s c e n c e p o l a r i z a t i o n immunoassay. S i m u l t a n e o u s l y N A P A was determined. The two-compartment open model was applied to calculate the P and NAPA concentration changes in the blood serum. The calculations of pharmacokinetic parameters were performed using the H e w l e t t - P a c k a r d computer. DeCreased concentrations of P and NAPA were revealed in rabbits with hyperlipidemia. The pharmacokinetic parameters were altered in animals of group 2 as well. Area under the curve and half-life for elimination were decreased, while volume of d i s t r i b u t i o n in central compartment and total body clearance were markedly increased. It is to be concluded, that P dosage should be altered in the presence of hyperlipidemia. Department of Clinical Pharmacology, Institute of P h a r m a c o l o g y and Toxicology, ~edical Academy, Powsta~c6w Wlkp. 72, 70-111 Szczecin, Poland

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TRANSTHORACIC IMPEDANCE CARDIOGRAPHY AS A METHOD FOR MEASURING HAEMODYNAMIC CHANGES IN HEALTHY VOLUNTEERS: REPEATABILITY AT REST AND TO SUCCESSIVE 70 ~ HEAD-UP TILTS P.A. Fowler, M. Thomas and S.M. Ludlow_ Postural stress induced by passive head-up tilt is a useful model for studying drug actions upon the cardiovascular system. We have examined the repeatability of this' technique using. impedance cardiography. Blood pressure and pulse rate were monitored using a Narco Scientific Sphygmomanometer. Cardiac impedance was monitored using a Minnesota Impedance Cardiograph. Repeatability of baseline measurements was examined in eight subjects. During a placebo controlled drug study. Coefficients of variation (CV) for baseline stroke volumes were 2 - 8% on the first visit and 3 - 13% on a second visit. In the same study readings taken at selected times for three hours after placebo treatment gave CV's of 5 - 12% for stroke volume and 3 - 9% for heart rate. Ten healthy male volunteers took part in a further study to look at the haemodynamic changes produced by tilting. Baseline readings of biood pressuie, hea;t rate and cardiac impedance were m a d e every 2 minutes over a 10-minute period with the subject supine. The subject was then tilted on a N o m e c O B Tilt table to 70 ~ head-up, and further readings were m a d e during the 10-minute tilt. The above procedure was then repeated: I0 minutes supine baseline followed by a tilt. There were significant changes (mean • SD) in stroke volume (-65.2 • 22.1mi), cardiac output (-2.8 • 1.2g/rain), peripheral resistance (+6.1 • 1.8),pulse rate (+15.8 • 6.8 b/m) P<0.001, and diastolic blood pressure (+3.8 • 3 . 4 m m H g ) P<0.01 between the initial supine period and the initial tilt. There were no significant differences (P>0.05) between the first and second tilting period. Impedance cardiography under basal conditions and after 2 successive head-up tilting procedures is a reproducible, rapid and safe method for measuring haemodynamic changes in healthy volunteers. Glaxo Group Research Ware Hefts. England.

REPRODUCIBILITY OF STROKE VOLUME MEASUREMENTS BY DOPPLER-ULTRASOUND AND IMPEDANCE CARDIOGRAPHY J. Xuhlwann, R. Hors~m~nn, H. Weber, H. s c A m i t z a n d ~ _ h ~ e In clinical pharmacological studies with cardiovascular active drugs the noninvasive methods Doppler-ultrasound (DSG) and impedance cardiography (ICG) are frequently used to determine the stroke volume (SV). To evaluate the within day variability at rest SV measurements were carried out with both methods in a crossover technique with 30 healthy volunteers four times within 1 hour. To compare the day to day variability of SV measurements by DSG and ICG under work load i0 healthy volunteers underwent a 3-step supine bicycle exercise (i00, 120, 140W; 3 min each) on the same days of 3 consecutive weeks. The repeated measurements were performed strictly under identical conditions. Statistical evaluation was performed by analysis of variance, Results (mean SV, ml): Within day variability (at rest): DSG ICG 0 min 160 125 15 min 161 126 30 min 159 126 60 m i n 157 125 Day to day variability (under work load): DSG ICG DAY 1 DAY 2 - - D A Y 3 DAY 1 DAY 2---DAY 3 i00 W 122 116 112 110 107 113 120 W 119 114 99 104 109 i13 140 W 113 117 109 92 103 103 Conclusions: DSG and ZCG lead to Comparable results of calculated SV at rest and under work load. SV values recorded by DSG were 10-25 % higher. Under lower work load levels of i00 and 120W ICG can be performed with smaller variability, undex submaximal exercise with 140W DSG indicates better reproducibility~ DSG and ICG are useful tools to detect hemodynamic effects in clinical pharmacological studies. Bayer AG, ~haZTaa-Forschungszentrum, Institut f~r Klinische Pharmakologie, D-5600 Wuppertal 1

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Withdrawn

HOW SHOULD ECHOCARDIOGRAPHICALLY MEASURED VENTRIOJLAR FIBRJ~ SHORTENING BE CORR~CTY2) ~OR CHANGES IN ~ T P~ATE TO EVALUATE POSITIVE INOTROPIC INTERVENTIONS? E. Schr6ter, G. Neusebauer The utility of non-invasive measurement of inotropic interventions by means of systolic time intervals (STIs) or mean left ventricular circ~nferential fibre shortening (mean Vcf) from M-mode echocardiography is widely accepted. Heart rate ( ~ ) changes per se lead to alterations in duration of STIs and to mean Vcf, which have to be cancelled out to calculate true inotropic effects. We analysed the usefulness of three different rate-corrections (individual, Weissler, Bazett) to obtain a rate-independent parameter of mean Vcf [mean Vcfc). In ten healthy male subjects ~ was increased by incremental i.v. doses of atropine sulfate either until a rate Of 120 b.p.m, or a total dose of 1.4 mg were achieved. Left ventricular ejection time (LVBT) was calculated from measurements of ECG, carotid pulse and phonocardiogram and mean Vcf from M-mode echocardiograms of the LV short axis. The mean regression of LVh~f vs. F~q closely resembled that of Weissler (slope -].7) with a slope of -].55, whereas individual slopes varied from -0.58 to -1.68. The theoretical line obtained with Bazett's formula deviated from the other two regressions especially below ~i~s of 50 b.p.m. There was a slight positive correlation of all individual values of mean Vcf with I~. In some subjects, however, also no correlation was present. After rate-correction of mean Vcf all three methods now led to a negative correlation of mean Vcfc with ~ , i .e. to an "over-correction" which increased from individual correction to the Bazett-correction. Therefore, it is proposed to calculate mean Vcfc either from individual relationships of mean Vcf with ~ or accorddng to our regression: mean Vcf = 0.0015 ~i~ + 0.87. Boehr inger M m m h e i m GmbH, I
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MILTIPLE DOSE HAEMODYNAMIC STUDY OF FAMOTIDINE IN HEALTHY MALE VOLUNTEERS. P. Salmon, A. Darragh, D. Fitzgerald, R. Lambe, Y. Hirata. Following a recent cormnunication (Lancet', September 19th 1987) which indicated the possibility of a negative inotropic effect on healthy volunteers with Famotidine, a new H 2 antagonist, a multiple dose haemodynamic study of Famotidine in healthy male volunteers was undertaken. This randomised double blind, placebo controlled two way crossover study used Duplex ultrasound to assess the effect on stroke index, cardiac index, pre ejection period, left ventricular ejection time and carotid and femoral blood flow. The results indicated that daily administration of Famotidine for seven days caused no clinically significant changes in any of the above parameters, and yielded no evidence of a negative inotropic effect. Institute of Clinical Pharmacology, Sir Patrick Dun's Hospital, Dublin 2, Ireland.

HEMODYNAMIC MEASUREMENTS ON DIFFERENT DOSES OF BREFANOLOL, AN ALPHA-.AND. 1 BETABLOCKING.. ~ AGENT 2 I . Helabl^, U. Gebuh~ , A. Nokhodian , M. Linde 2, A. Halabi z, W. K i r c h In animal experiments b r e f a n o l o l has been shown t o e x e r t s e l e c t i v e a l p h a - r e c e p t o r blocking p r o p e r t i e s and non-card i o s e l e c t i v e b e t a - r e c e p t o r blocking e f f e c t s . Aim o f the present study was t o compare the hemedynemic e f f e c t s o f b r e f a n o l e l with those o f p r o p r a n o l o l . Following randomized a l l o c a t i o n 12 hypertensive p a t i e n t s were t r e a t e d in a p l a c e b o - c o n t r o l l e d crossover study with s i n g l e o r a l doses o f 80 mg p r e p r a n o l o l , 50 and 100 mg b r e f a n o l o l (9 male,' 3 r e male, mean age 57.7 + 9 y r s . , b.w. 77.8 + 9.4 kg, X t SO). 2,4,6,10 and 24 hrs a f t e r each treatment-phase heart r a t e , blood pressure, venous occlusion plethysmagraphy, meehanoand impedance cardiography were measured under standardized c o n d i t i o n s . 80 mg propranelol caused the well-known hemodynamic a l t e r a t i o n s o f betablockers meaning reduction o f heart r a t e , blood pressure, cardiac output, a r t e r i a l blood f l o w and an increase o f the p r e e j e c t i o n period (PEP) and the r a t i o PEP/LVET. 100 mg b r e f e n o l o l produced the same hemodynamic changes as p r s p r s n o l o l with the exception t h a t s y s t o l i c and d i a s t o l i c blood pressure values were r e duced more d i s t i n c t l y (156 + 11/97 t 3 mmHg before t r e a t ment and 137 + 17/83 + 5 mmHg 4 hrs a f t e r a d m i n i s t r a t i o n o f b r e f a n o l o l - l O 0 mg)[ Also 50 mg b r e f a n o l o l s i g n i f i c a n t l y reduced heart r a t e , blood pressure as w e l l as cardiac output. A r t e r i a l blood f l o w ( r e a c t i v e hyperaemia), however, increased 4 hrs a f t e r a d m i n i s t r a t i o n o f t h i s dose o f the drug from 24.4 + 7.6 ml/lO0 ml t i s s u e x min (befsre t r e a t ment) t o 28.3 +-7.0 ml/lO0 ml t i s s u e x min. In conclusion, hemodynamic e f f e c t s with both drugs and both dosages o f b r e f a n o l o l were already seen 2 hrs a f t e r a d m i n i s t r a t i o n with a maximum e f f e c t 4 hrs a f t e r dosing. 10 hrs a f t e r wards no hemedynamic e f f e c t s were seen anymore. Dept. o f Family Medicine, U n i v e r s i t y o f C a l i f o r n i a , Los Angeles, USA- , I . Med. H o s p i t a l , C h r i s t i a n - A l b r e c h t s - U n i v e r s i t ~ t , K i e l , ERGermany

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DYNAMICS AND KINETICS OF ADIBENDAN, A NEW ORALLY ACTIVE POSITIVE INOTROPIC SUBSTANCE, UNDER STEADY STATE CONDITIONS W. Akpan, E. v.M611endorff, G. Neu~ebaucr 16 healthy m M e v o l u n t e e r s received adibendan (A) or placebo (P) p.o. over 9 days in a double blind randomized parallel group study. Single doses of 3 mg A were administered on day 1 and 9, b.i .d. regimen from day 2 to 8. In order to evaluate the inetropic effects of A the systolic time intervals (STI), heart rate and blood pressure were measured about ] h before and 2 and 11 h after each morning dose. Concentration-time profiles were determined on day 1 and 9. Phamacodynamic parameters two hours post-drug are given in the following table:

SIMULTANEOUS MEASUREMENT OF PERIPHERAL BLOOD FLOW COMPARING IMPEDANCE PLETHYSMOGRAPHY AND LASER DOPPLER SONOGRAPHY J. Ulmer, C. Szypula, U. The]B, G. Wieckhorst and P.W. L~eker To evaluate the pharmacodynamie effect of drugs in clinidal pharmacology, non-invasive, uncomplicated, reliable and reproducible methods are needed. Two of these methods, Impedance Plethysmography and Laser Doppler Sonography are applied simultaneously to evaluate the effects on peripheral circulation (regional, general and local) relative to the following criteria: rest, exertion/reactive hyperaemia/heat, cold/position of the site of measurement/Valsalva manoeuvre/orthostatic effects/nicotine and caffeine effects. A standard procedure for both methods will be described. Both techniques will be tested for their validity, reliability and reproducibility. Drug effects on peripheral blood flow can affect arterial input in general or produce a change only in cutaneous microcirculation. Thus, the above techniques are not equally appropriate in order to focus on thesedifferences. The use of both methods simultaneously gives additional information and is still easy to carry out. The results show a good coincidence with the expected effects. Methods: Impedance Plethysmography: change of tissue resistivity on high frequency - low intensity alternating current. Laser Doppler Sonography: Doppler effect of reflected monochromatic light on moving intravasal particles. Statistics: n-lO, paired t-test. Institut f~r klinische Pharmakologie Bobenheim, Riehard-Wagner-Str. 20, D-6718 GrUnstadt

D a y 11 Parameters: P I~ b.p~'m. ...... 59s Ps mmlig 1.16.9+2.7 ~E d nmflig 71.~3.6 QSZc ms -4.6_+2.7 LVETc ms -5.2+1.7

Pms

A 64s 116.0+2.6 67,~2.4 ~34.~8.4 ~ -12.777.2

[ ..... Day "9 " [[' P [ " [ 61s 70+4 []18.8+4.0 1 2 0 . ~ 4 . 3 [ 64.~4.7 63.~4.3 I - 3 . ~ 4 . 0 -39.3~]1.9" I -2.7~4.1 - ] 8 . ~ 8 . 3 87.0+8.0*

103.0Z40 8 .0 60. ll010V O I

TJtest

means and SEM

* p < 0.05 vs )lacebo

Signifikant positive inotropic effects and increases in heart rate were present on each study day at 2 h post-drug. No tolerance to the positive ]notropic action was observed. During steady state increases in maximum concentrations, AUC's and elimination half-life were seen. Close concentration-effec~ relationships could be demonstrated. Boehringer Mannheim GmbH, Klinische Pharmakologie, Sandhofer Str. 116, D-6800 Mannheim 31

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SKIN BLOOD FLOW F O L L O W I N G I N T R A D E R M A L B R A D Y K I N I N M E A S U R E D BY LASER D O P P L E R F L O W M E T R Y T.C. Li K a m We, N.E. Almond, E.D. Cooke and P. T u r n e r Skin response to intradermal bradykinin (Bk) has been studied by m e a s u r e m e n t of weal thickness or area and flare area. The latter is an i n s e n s i t i v e assessment of skin b l o o d flow changes b e c a u s e the flare outline is not always c l e a r l y d e f i n e d and v a s o d i l a t a t i o n can be present in the skin in the absence of visible erythema. The n o n - i n v a s i v e t e c h n i q u e of laser D o p p l e r flowmetry (LDF) enables changes in skin b l o o d ~low to be measured. It is s u g g e s t e d that this may p r o v i d e an a l t e r n a t i v e o b j e c t i v e m e a s u r e m e n t of the skin response to intradermal Bk. The LDF output from the f o r e a r m skin was recorded in 5 h e a l t h y subjects, aged 23-33 years, after intradermal injection of incremental doses (1-20 ug)'of Bk in normal saline. The skin b l o o d flow m e a s u r e d by LDF i n c r e a s e d rapidly d u r i n g the first two minutes after intradermal Bk and p e a k e d b e t w e e n two and four minutes. The peak LDF v a l u e s d i d not allow clear d i f f e r e n t i a t i o n b e t w e e n the Bk doses. H o w e v e r there was a Bk d o s e - r e l a t e d increase in LDF output when the data at 15 minutes were used. The LDF output f o l l o w i n g 20 ug Bk was reduced c o m p a r e d with the i0 ug dose. This may be due to capillary c o m p r e s s i o n or r e d u c e d light penetration in the presence of a large weal. The dose response curves were similar i r r e s p e c t i v e of w h e t h e r the response was expressed in absolute LDF values or as a p e r c e n t a g e increase relative to baseline. These results suggest that LDF is a useful, objective m e t h o d of a s s e s s i n g skin response to intradermal Bk and it may prove useful in the i n v e s t i g a t i o n of interactions by other agents on this effect. Since l~ser D o p p l e r only m e a s u r e s flow in a very local area (i mm-) and there may be spatial v a r i a t i o n in b l o o d flow and asynunetry of the h y p e r a e m i c response, it is s u g g e s t e d that the sensitivity of the m e t h o d may be improved by making several measurements across the flare and computing a mean p e r f u s l o n to the region. D e p a r t m e n t of Clinical Pharmacology, St. Bartholomew's Hospital, London ECIA 7BE.

DUPLEX DOPPLER ULTRASONOGRAPHY - A NEW APPROACH TO MEASURE DRUG EFFECTS ON HEPATIC BLOOD FLOW R. Zahorsky*, A. Maas, G. Leimenstoil, U. Hohenspein*, M. H6fig* Hepatic blood flow (HBF) is usually investigatedby indocyanine green

(ICG) clearance. However, the injection of ICG might be accompanied by complications, e. g. allergicreactions. Moreover, a constant extraction ratio is required, which is not equal in different stages of liver function. Recently a non-invasivemethod, which measures the blood flow directly into vessels of the liver - duplex doppler ultrasonography (DDUS) - has been made available. The aim of the followingstudy w as m compare both methods using the known blood flow reducing effect of propranolol. Study Procedure: 9 healthy, male volunteers between the ages of 24 and 38 were investigated. After a period of 12 hours fasting each received a placebo to begin the study. After a resting period of 90 minutes the HBF was measured by both methods. There after the volunteers received 80 mg ofpropranolol (P). Once again after a ninety minutes restingperiod a second me asurement of HBF was performed using both methods. The HBF measured by ICG (t296 ml/min) and DDUS (1254 ml/min) was in accordance with the results found in the literature (1350 ml/min).After the administration of P a significant reduction of HBF (1296 to 978 ml/ min(ICG) and 1254 to 1107 ml/min (DDUS)) was observed. The amount of decrease in HBF as measured by DDUS was induced by significant changes (P < 0.05, Wilcoxon test) in blood flow of the portal vein, whereas the blood flow in the hepatic artery remained constant. Therefore the duplex doppler ultmsonography is suitable forinvestigationsof the HBF. A significantnegative correlation (Rs = -0.81, P < 0.05, n = 8) was found between the changes of HBF (ICG) and the changes in blood flow of portal vein (DDUS). This could lead to the suggestion, that even in healthy subjects ICG is affected by increasing extraction ratio with decreasing HBF. In contrast DDUS reflects changes of reduction in HBF only. In conclusion DDUS seems to be an accurate, risklessnon-invasiveand anytime usable method to estimate HBF, at least comparable to ICG. Abteilung Nephrologie, *Abteilung Klinische Pharmakologie, I. Medizinlsche Klinik der Christian-Albrechts-Universi~tKiel, FRG, 2300 Kiel

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CHROMAMETRYAND LASER-DOPPLER FLOWMETRY: INTEGRATEDESTIMATIONOF SKIN PERFUSION ~0ffler, A., Seifert, W., and Stake T. Non-invasiveperfnsionmeasurementscan be carriedout by variousmethods. These include venous-occlusionplethysmogaphy,transcutaneonsp02/pC02measurements, Doppler methods and chromanetry,adaptedby us for biomedicalmeasurements.All mentioned techniquessupply only one more or less quantifiablestatement,only chromametryproducestwo parametersin a single pass: the colour angle as expression of the blood gas content and the distanceas the expressionof the plethora. Methodic effort, reliabilityof measurementtechniqueand artefactrecognizability led to the selectionof ehromametryand laser-dopplerfor measurementsat a limb (left forearm) with experimentallychangedblood flow. The sensor of the laserdoppler was attachedto the inner left forearmby an adhesivering. The measuring head of the chromaneterwas placed against the skin in its ilmediatevicinity. After a 10-min. resting and adaptationperiod, ascendingback-pressuresof 50 ~ g (outflowobstruction),90 mmHG (outflowand inflowobstruction)and 160 nHG (complete block) were appliedsubsequentlyfor 5 mia. in each case. The cuff pressure was then completelyreleased.Measurementswere carriedout at each minute.

I N F L U E N C E OF F E N O T E R O L ON U M B I L I C O - P L A C E N T A L CIRCULATION R. K o v ~ M. Kri~ka~ V. G ~ b o r i k o v ~ L. Bebjak~ J. Stencl

In the adaptationphase, all the values remainedstable. With the increase in congestion,there is a 3oo reduction in the flow while the plethora, expressedby distance, increases. The blood gas contentchanges 200 with the consumptionof oxygen (angle from 90~ to 180~ The release of the pressure leads to the ~oo complete picture of reactivehyperemia with a strong flow and strong srterJalization, o

ANGLE (DEGREES) DISTANCE (Rs .U~ITS) CUfF ~Rc~s. mmHG ~

'

flow

~ 5

10

15

20

~'-~--=25 30

35

in,nudes

The combination of laser-doppler and chromametryrepresents a valuable contribution to the alternativesavailablefor the course controlof pharmacologicalor pathophysiologicalparameters. Humanpharmako!ogieI, ScheringAG, Mullerstra~e172, i000 Berlin 65

F e n o t e r o l (F) b e l o n g s to the most f r e q u e n t l y used drugs with t o c o l y t i c action. The p r o p o s e d b e n e f i tial e f f e c t of F on f e t o p l a c e n t a r circulation was m e a s u r e d in an open study. U s i n g D o p p l e r s s o n o g r a p h y u m b i l i c a l blood flow v e l o c i t y was m e a s u r e d in 16 p r e g n a n t w o m e n b e f o r e and after 7 days F ( P a r t u s i s t e n ) t r e a t m e n t in the 30,7 mea.n weeks d u r a t i o n of p r e g n a n c y with p a r a l e l m o n i t o ring of fetal f u n c t i o n s . A/B r a t i o s as a p a r a m e ter of u m b i l i c o p l a c e n t a l c i r c u l a t i o n was d e c r e a sed in i0 women. A n o n - s i g n i f i c a n t i n c r e a s e of fetal h e a r t rate was d e b e c t e d . To e l u c i d a t e the mode of a c t i o n of F f u r t h e r 132 fetal pulse c u r v e s in &6 F t r e a t e d p r e g n a n t w o m e n were m a t h e m a t i c a l l y a n a l y s e d . The e x a m i n a t i o n showed a s l i g h t s h o r t e n i n g of fetal c a r d i a c c y c l e (0,39 + 0,03) and n o n - s i g n i f i c a n t c h a n g e s of a c c e l e r a t i n g time (0,i04 + O,Ol). The r e s i s t a n c e of p l a c e n t a l v e s s e l s bed was significantly d e c r e a s e d . Our r e s u l t s s u g g e s t that F d e c r e a s e s not only the u t e r u s m u s c u l a r tone but d e c r e a s e s the r e s i s t a n c e of p l a c e n t a l v e s s e l s bed as well. H e d i c a l b i o n i c s r e s e a r c h i n s t i t u t e , J e d Z o v a 6, 8 r a f i s l a v a , CSSR.

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REPEATABILITY ANALYSIS OF BLOOD PRESSURE OBSERVATIONS

EFFECTS OF A PERIPHERAL AND CENTRAL ANTICHOLINE R G I C IN H E A L T H Y S U B J E C T S C.Abraham, R.G.Alken, H.HGller Single increasing oral doses (1.5 a n d 3mg) of a new anticholinergic agent (ALE-007) were given to nine healthy subjects at d o u b l e - b l i n d conditions. There was an i n c r e a s e in ratings for symptoms like dry mouth, thirst, drowsiness in the v.Zerssen S c a l e of c o m p l a i n t s . There was no effect on cardiovascular parameters including pulse rate, blood pressure at r e s t a n d s y s t o l i c time intervals. Psychomotor activity as a s s e s s e d by tapping speed and screwing nuts onto bolts was slightly impaired. There was a considerable reduction of p e r f o r m a n c e in the panel-d2-Test done to a s s e s s a t t e n t i o n at stress. Pupil size at m o d e r a t e background illumination and accommod a t i o n p r o v e d to be a f f e c t e d f o r u p to 1 2 h post dose. The reduced visual accommodation might have biassed the performance of t h e attentionstress-test (panel-d2-test), since both effects exhibited to b e p a r a l l e l in t i m e a n d m o s t of t h e subjects complained about difficulties in reading.

M.J.Jamieson S.H.D.Jackson* and T.M.MacDonald Repeated measures of blood pressure (BP) within an individual by a single observer will vary. This variation is due to true intra-individual variation, mechanical imprecision and observer imprecision. Once a systematic difference between duplicate measurements has been excluded, for example by paired t-test, the appropriate method of analysis of such data is by repeatability analysis ~. This analysis derives a mean difference between observations (which will be close to zero) and a repeatability coefficient (r'), with units of mmHg, which represents the absolute value within which a second measurement would occur on 95% of occasions. In an attempt to identify that component of variability in BP measurements due to observer imprecision, videotapes (with syr)chronous soundtrack) of failing mercury sphygmomanometer columns were shown to 24 experienced observers practising in 15 Units throughout the U.K. 10 columns (BP range 136-250/84132) were recorded, duplicated and re-edited in random order. The overall mean differences between duplicates were: systolic 0.5mmHg (95% CI -0.2, 1.3), diastolic 0.3mmHg (95% CI -0.3,1.0). The remaining results are shown in the table.

MEAN DIFFERENCE SD OF DIFFERENCES r'

SYSTOLIC range

DIASTOLIC range

-2.4 to 4.4 1.0 to 7.4 1.9 to 16.7

-3.1 to 4.2 0.9 to 8.9 1.7 to 17.0

These figures indicate the extent of intra-observer disagreement that can still be seen when variation due to patient and device factors has been excluded. This disagreement would account for a substantial proportion of the variability seen in blood pressure measurement. 1, Jackson SHD, Johnston A. Brit J Clin Pharmac, 1988, 25, 642P-643P. 2, BS 5497: Part 1: 1987. British Standards Institution.

Institute of C l i n i c a l Pharmacology, University, P O B 140, B e r l i n , 1 0 4 0 ,

HumboldtGDR

Clinical Pharmacology Unit, Aberdeen University, Aberdeen AB9 2ZD and *Kings College Medical School, London.

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ASSESSMENT OF CLINICAL IMPRDVI~4ENT IN INTERMITI~q79 CLAUDICATION

THE ASSESSMENT OF NAUSEA A. Del Favero, F. Nmila*, C.Bamrto*, V. ~ * , E. Ballatc~iw L. Patoia, M. Torero* and G. T o ~ i * * . Istituto di ClJnica Medica i Universi~ di PerUSe, *DivisiQne di Onoolos~ Medica Ospedale Policlinioo di ~ , w Dipar't/m~'~/~ d i Scienze Statistiche thiversit~ di P~-t.~ia, Italy. ** Istituto di Ricerche FsrmacoloEiche '~4.NeEri",Milano,ltaly. Emesis induesd by c~mce~ c h ~ is a r~levaat clinical problem snd rile efficacy of smtiemetic ckt~s has been evaluated in many clinical ~rials; much less attestiun has been devoted to the search fcr reliable m~zrem~nts of nausea.In order to provide new infatuations an the validi ty of e x i s t ~ methcds fc~ evaluation of reusea ~nd due best ~ to utili ze ~duamin clinical trdals we have oo,paratively essessed in a standardi zed way 3 differ~ut methods ef m e a ~ r~a~ea in 849 patients (pts) en rolled in 4 double blind r ' ~ clinical trials and 2 observaticr~l studies. Naamm ~ s measured befc~e and at 2,4,6,8 and 24 hours afte~ due by ~ a d e s c ~ t i v e s~le (os), a v i s u a l a~alo~ s c a l e (VAS) and an asaloK e a ~ : i a s a s s d ~ c m a t i c s c e l e (ACCS) a~d ~ s e ' ~ . l ~ d acc~'to 4 different dimm~iass: maximal intersity (MI) which is the est value of som~ obtained wihh DS,VAS ~ ACCS at any evaluaticn carried out over hhe 24th period; entity (E) ~uid% is the sum of all the values of intessity of r~usea (1) ~ at each evaluatiua time; dmaties (D) expressed in minutes at each e~aluatiua time and quautity (Q) defined as the sum of the prod~tB of I multiplied by D , ~ at each evaluation time. D ~ c r s of the mess~mants of nausea in hhe p ~ t i c n sAudi ed, s@~ament sines8 scales s~d ~heir sensitivity ~nd ~ amo~ climer~icns stud their sensitivity were smalyzed. A unifcrm distribution of nam~esmms~ant~ was found only in p t s receivi~ chemofb~py wid'Eut s~y afciemetic treah~est. There was a suhstaatial equivalence of the different scales used,~x~ri~ no advant~es in usin~ an smalo~ (VAS) r e s p e c t to a~scr~ptive (DS) scale. A t~md toward inc~esin~ s a - s i t i v i t y i n dete ctir~ diff~ness as %he dima~i~as of n a u ~ esnsidered became ~ r e p r ~ i v e of ~ e vardcus sspec~ of this symptom (Q more sensible ~ E more s~sible ~ MI) ~ s observed. Istituto di C l i n i c a Medica i, Uni%~csit~ d i P e r t ~ i a , ~ , I t a l y .

H. R. Watson, C. P. Shearman and G. Belcher Four clinical trials in intenuittent claudication ~uployed treadmill exercise tests as the primary endpoint and used a cc~mon protocol. Subjective assessments of improvement were also made in all cases. 147 patients were included in total. Different asses~nents of limb blocd flow and peripheral haemodynamics were performed in each study. All patients were assessed on entry to the study and over a period of twelve weeks after starting. A comparison was made of the changes with time in the treadmill exercise tests, subjective assessments and the various objective tests. Improvements were seen in maximum walking distance, 96% (+20), and the distance at onset of claudication, 108% (+27), over the twelve week period. Subjective assessments by the clinician (r=O.31, p=O.OOO2) and by the patient ( ~ . 3 2 , p=O.OOOl) correlated with the results of treadmill exercise tests. However, the changes in objective assessments (ankle-brachial pressure index, ankle pressure recovery time, transcutaneous oxygen tension, transcutaneous oxygen tension recovery time, pulse volt, he recording) did not correlate with the clinical improv~uents shown. A large improv~nent in exercise tolerance was demonstrated by treadmill exercise tests, but the results suggest that the objective tests used are not useful in measuring improvanent in the clinical symptc~as of patients suffering frc~a intermittent claudication. Schering Health Care Ltd, The Brow, Burgess Hill, RHI5 9NE, England.

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ON THE LINEARITY OF RELATIONSHIP BETWEEN EPIGASTRIC IMPEDANCE AND GASTRIC VOLUME J.A. Sutton Epigastric impedance (EI) produces comparable gastric emptying rates to existing methods (1,2). Theory predicts linear relationships between surface EI and volume of internal organs when resistivity ef organ contents is constant. Gastric filling EI responses (Ohms) to 6 x 62, 125, 250, 375, 500 and 750 ml of an orange cerdiai (Quash(R) - water : I-5) "meal" were studied in 2 volunteers. Standard Ag/AgC1 electrodes and positions were used (1,2). Fig 1 shows best fit curves for the 6 meals at each volume were linear. Coefficients of variation (SD/Mean) averaged 35 and 27% (Range 14 - 50%) for 250 - 750 ml, which is comparatively low for biological observations (3).

A SINGLE RISING NTRAVENOUS DOSE TOLERANCE AND PHARMACODYNAMIC STUDY OF ALPHA AND BETA HUMAN CALCITONIN GENE RELATED PEPTIDES (CGRP) IN HEALTHY MALE VOLUNTEERS. P. Salmon, D. Fitzgerald, R. Lambe, A. Darragh, D. O'Shaughnessy, A, Riddell, U. Ney. Calcitonin gene-related peptide is present in sensory nerve fibres in the heart and peripheral arteries. Two separate CGRP genes have heenidentified encoding CGRP alpha and beta which differ by three and one amino acid respectively. In a series of rising doses, the cardiovascular effects of alpha and beta CGRP were examined and compared using Duplex ultrasound. Significant increases in common carotid blood flow and mean velocity occurred following infusion of 8ng,%2ng, and 16ng/kg/min of alpha CGRP and following 8ng and 16ng of beta CGRP. Internal carotid blood flow and mean velocity increased at all doses of alpha but at only the two higher doses of beta CGRP. Similar increases were noted in the external carotid. The increases in cardiac output were expected in view of the known chronotropic and inotropic effects of CGRP. There were no clinically significant adverse reactions or changes in laboratory parameters or ECG indices. The results seem to indicate that cardiovascular effects of alpha CGRP are greater than those of beta CGRP. Institute of Clinical Pharmacology, Sir Patrick Dun's Hospital, Grand Canal Street, Dublin 2, Ireland.

2

Volunteer 2

Volunteer 1

!

0 0

.... Best Fit

Meal Volume (ml)

--

= Group Means

Refs: 1. Sutton, Thompson & Sobnack, (1985) Lancet 898-980 2. McClelland & Sutton, (1985) Gut, 26 6 607-14 3. Feinstein AR (1977) Clinical Bios~tistics, The CV Mosby Co., New York. Clinical Pharmacology Unit, Roussel Laboratories Ltd., Kingfisher Drive, Covimgham Park, Swindam, SN3 5BZ, UoK.

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THE FRACTION OF PARACETAMOLABSORBEDAS AN INDEX OF THE RATE OF GASTRIC EMPTYING M. van Wyk, De K. Sommers, E.C. Meyer, J Moncrieff and P.J. Becket The purpose of this study was to measure gastric emptying by using the modified Wagner-Nelson method (L. Hendeles, R.P l a f r a t e , M. Weinberger. Clin. Pharmakokinet. 9, 95, 1984) of calculating the fraction of an oral dose of paracetamol absorbed over time. To correlate the accurateness of this method as an index of the rate of gastric emptying, six healthy s t a f f members were entered into an e t h i c a l l y approved t r i a l using the following in cross-over experimental design i ) Paracetamol 2g 2) Paracetamol 2g taken with breakfast 3) Codeine 180mg, followed lh l a t e r by paracetamol 2g plus breakfast 4) Paracetamol 2g taken with breakfast, followed 5 min l a t e r with metoclopramide 20g i . v . 5) Codeine 180mg, followed lh l a t e r by paracetamol plus breakfast, followed 5 min l a t e r with metoclopramide 20mg i . v . Treatments 6, 7 and 8 were r e p e t i t i o n of 3, 4 and 5 but without food. The rate and extent of gastric emptying was studied by analysing the paracetamol concentration in serial blood samples and calculating the fractional absorption for each treatment regimen. Compared to when paracetamol was given alone, the fraction absorbed and therefore the rate of gastric emptying was s i g n i f i c a n t l y increased by metoclopramide and decreased by codeine and food. Our results compared and correlated well with those previously described by various authors for the effects of metoclopramide, codeine and food. This method appears to be a sensitive method for the measurement of gastric emptying. Department of Pharmacology, University of Pretoria, P.O. Box 2034, Pretoria, 0001, R.S.A.

SCREENING FOR DRUG EFFECTS ON REACTION TIME IN PARKINSONISM: METHODOLOGY S.G. Bowes, C. Frith, C. Walker, P, Clark, A.A. Deshmukh, C.J.A. O'Neill, R.J. Dobbs and S.M. Dobbs. The relative performance of Parkinsonian patients in simple and choice reaction time (RT) tests differed from that of age matched controls (C. Bloxham et el. Brain, 106, 257, 1984). We have confirmed the findings of this small study in 139 volunteers, aged 30-89 yr and 42 patients wlthidiopathic Parkinsonism, aged 52-85 yr, and have further defined discriminating test conditions. Subjects responded to a command on the computer screen to raise left or right index finger from its pressure sensitive support, following a 'ready' signal, which either did (simple task), or did not (choice task), warn which side was to be lifted. The delay between 'ready' and 'go' was either fixed at 2s or varied randomly between i and 3s. Probabilities given refer to analysis of variance of the effects of test conditions on log transformed, age adjusted RT data. The former was necessary to give normally distributed residuals, the latter because of the effect of age on log RT (P<0.0001). Mean RTs quoted are adjusted to the mean age, 61 yr, for all 181 subjects. RT was slower in Parkinsonians (P<0.O001). Warning reduced RT (P<0.0001), but more so in normals, from 571 (95% C.I.:533,590) to 411 (398,425)ms, than in patients, 721 (678,766) to 594 (559,631) (P
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TOWARDS SCREENING FOR A PRE-CLINICAL STATE IN IDIOPATHIC PARKINSONISM: METHODOLOGY C.J.A. O'Neill, C. Weller, C. Walker, P. Clark, A.A. Deshmukh, S.G. Bowes, S.M. Dobbs and R.J. Dobbs Environmental substances have been i m p l l e a t e d in the pathogenesls of Parklnson's disease, making prevention a possibility. B monoamine oxidase, Inhibitors of which are used in treatment, may bring about their biotransformation to neurotoxins. Definition of a pre-cllnlcal state is a pre-requisite for prophylaxis: objective measurement should be useful in defining it. The terms, rigidity, tremor and postural abnormality, themselves designate the presence of clinical signs. However, it is often difficult to say when poverty or slowness of movement are sufficiently well developed to constitute hypo- or bradyklnesia. As a preliminary to attempting to identify a pre-elinical state, we have measured distance/ time parameters of gait (L. Klenerman et al., Age Ageing, 17, 397, 1988), barefoot, at free walking speed over 20m in 136 healthy volunteers, aged 30-88 yr, and 39 patients, 51 to 85 yr, with clinical Idiopathie Parklnsonlsm. Probabilities given refer to analysis of variance of the effect of subject group on age adjusted gait parameters. Log transformation was necessary for swing length and double support time, but not for speed, in order to give normally distributed residuals. Age had a significant (P
EFFECT OF PSYCHOLOGICAL STRESS ON GASTRIC POTENTIAL DIFFERENCE IN MAN. J.M.Segrestaa, J.F. Bergmann, T. Morell and C. Caulin Stress causes gastric mucosal damage but suitable method in clinical pharmacology for the evaluation of drugs which prevent or treat stress-induced gastric lesions are rare. This study investigated the effect of three different mental stress tests on gastric electric potential difference (PD) which measures the ions H + back diffusion due to the mucosal lesions. PD measurement was carried out in six healthy volunteers using the agar-KCl bridges method (Eur. J. Clin. Pharma.1982, 22, 147) during dichotomous listening (DL), the ringing of a telephone and a 90 dB noise. Cardiac and psychological responses to stress were evaluated at the same time. Two subjects had no change in PD as well as no extragastric modification due to the stressor. The four other volunteers had a marked stress-induced fall in PD (12.5 +- 5.6 mV) with a simultaneous acceleration of heart, an increase in systolic blood pressure and anxiety feelings evaluated on a visual analogue scale. These results, especially those observed after the DL, indicated that simple auditive and psychological stress induces early and persistant changes in the gastric mucosa with H+ ions retrodiffusion an a fall in PD. Its correlation with the non gastric effects of the stress makes this model useful in therapeutic research into the prevention and treatment of stress-induced gastric lesions. Clinique Th6mpeutique, H6pital Lariboisi~re, 2, rue Ambroise Par6 75475 PARIS CEDEX 10 (France).

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VARIABILITY OF PENTAGASTRIN STIMULATED ACID OUTPUT C. Broom and G. Acton Pentagastrin stimulated g a s t r i c acid output is widely used to measure the e f f e c t s of a n t i s e c r e t o r y drugs. We m e a s ured g a s t r i c acid output in 16 healthy male volunteers [mean age 29 years (range 23-38), mean weight 76kg (range 60-90)]. Intravenous pentagastrin (O.6mcg/kg/hr) was i n fused f o r one hour on each of 4 separate study days f o r each subject. Gastric secretion was aspirated continuously and collected i n t o 15 minute a l i q u o t s . Mean (M.A.O.) and peak (P.A.O.) acid outputs were calculated f o r each subject on each day and f o r each of these measurments the mean values, standard deviations (S.D.) and coe f f i c i e n t s o f v a r i a t i o n (C.V.) over a l l study days were derived. Results were:Subject M.A.O.(mmol) P.A.O.(mmol) Mean S.D. C.V. Mean S.D. C.V. 1 7.9 1.2 15% 8.6 1.5 17% 2 5.6 I.I 20% 6.0 1.3 22% 3 6.5 0.7 11% 6.7 0.9 13% 4 7.0 0.9 13% 7.4 0.9 12% 5 5.3 1.0 19% 5.8 0.7 12% 6 4.8 0.7 14% 5.1 0.6 12% 7 5.3 2.4 45% 5.6 2.1 38% 8 5.9 1.4 24% 6.5 1.6 25% 9 4.8 1.6 33% 5.1 1.4 27% I0 5.1 0.6 12% 5.3 0.9 17% II 7.0 0.7 10% 7.5 0.4 5% 12 5.3 1.3 24% 6.4 0.7 11% 13 6.5 1.2 19% 6.9 1.3 18% 14 8.6 3.0 35% 9.2 3.1 34% 15 8.5 0.7 8% 8.8 0.7 8% 16 6.3 0.8 13% 6.8 0.6 9% There was considerable within subject v a r i a b i l i t y on d i f f erent study days (MAO: average 20%, PAO: average 18%). This must be taken i n t o account when assessing the e f f e c t of a n t i s e c r e t o r y drugs. Smith Kline & French Research L t d . , The Frythe, Welwyn, Herts., AL6 9AR, U.K.

USE OF DIMETHICONE IN THE PREVENTION OF THE FALL IN GASTRIC POTENTIAL DIFFERENCE INDUCED BY BILE SALTS. J.F. Bergmann, G. Simoneau, G. Chanteclair, C. Caulin and J.M. Segrestaa. The duodenogastric reflux is a functional anomaly which may induce lesions of the gastric mucosa. It cause a weakness of the gastric mucosal barrier and a back diffusion of H+ ions easily shown by measurement of the transgastrie potential difference (PD). The aim of this study was to determine whether dimethieone, a silicone gastric topic, devoid of antacid activity, could lower the fall in PD induced by taurocholate bile salts. Ten healthy volunteers (age 22-27) had two PD measurements (using the KCl-Agar bridges method) after administration p.o. of 0,2 mM of sodium taurodeoxycholate (TDC) with placebo or with 2,2 g of dimethicone in a simple blind, cross-over, controlled, randomised study design. With dimethicone, the fall of PD is less severe (A max 16.1 -+ 1,0 mV versus 24.8 + 0.9 mV p < 0,01), the area upper curve is smaller (257.2 ---40.8 versus 566.2 + 46.1, p < 0,01), the duration in changes of PD is briefer (32 rain versus 51 rain, p < 0,01) compare to placebo. The dimethicone has no activity on gastric emptying and no buffer effect. Its property in the diminution in the fall of gastric PD could be related to an increase in the cytoprotective capacities of the gastric mucosa. In conclusion 1) Tanrodeoxycholate induces fall in gastric potential difference which could be related to gastric mucosa lesions. 2) This method may be useful as a pharmalogical model for the study of the duodenogastric biliary reflux. 3) This fall can be significantly diminished by the prior intake of dimethicone which probably has a "mucosa protective" property t o w a r d s this bile salt. Clinique Th6mpeutique. H6pital Lariboisi~re 2, rue Ambroise Par6 75475 PARIS CEDEX 10 (France).

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EFFECT OF DOSE IN NON-RESPONDERS TO RANITIDINE S. Walker, D.R. Krishna and U. Klotz

CLINICAL CHARACTERISTICSOF ROXATIDINEACETATE: A REVIEW

Some peptic ulcers are resistant to adequate treatment with a H 2receptor antagonist and only few of them heal after switching to a different H2-blocker. We found recently a higher frequency of so-called non-responders among patients with cirrhosis. The reason(s) of this phenomenon are yet unknown. To identify any dose-dependency of the clinical proble m we tested the effect of a high dose of ranitidine (900 rag) in patients with (n = 10) and without (n = 7) cirrhosis in whom a normal 300 mg dose of ranitidine had failed to suppress acid secretion. Night-time intragastric pH was continously monitored. A rise in the intragastric pH above 4.0 for more than 6 h following the oral dose at 6 pm was considered as response. In addition, plasma levels of ranitidine were monitored by HPLC to exclude pharmacokinetic problems. Among the 10 patients with cirrhosis, 5 did also not respond to the high dose of ranitidine. Similarly, only in 3 of the 7 control patients the 3-fold increase of ranitidine's dose resulted in sufficient acid suppression. In all subjects plasma concentrations of ranitidine (e.g. 4h postdosing) were high enough to inhibit gastric secretion. In non-responders (responders) these levels (mean • SD) increased from 666 _+ 321 ng/ml (501 _+ 268 ng/ml) following the 300 mg dose to 1948 • 842 ng/ml (1848 _+ 1027 ng/ml) after the 900 mg dose. Thus, pharmacokinetic factors can not account for the treatment failure. In conclusion, pharmacodynamic reasons for the non-response to the standard dose of ranitidine have to be assumed, it appears possible to overcome this resistence in some patients by e threefold increase of the dosage. However, long-term treatment with such high doses will also elevate the risk for side effects.

R. Labs, W. Bender, H.G. Dammann

Pharmacodynamic studies revealed that 150 mg of roxatidtne acetate were optima] in suppressing gastric acid s~cretion, and that a single bedtime dose of 150 mg was more effect i v e than a dose of 75 mg twice daily in terms of inhibiting nocturnal acid secretion. When administered orally as a capsule containing a granule formulation, the drug displayed modified-release properties, which led to a sustained suppression of gastric acid secretion. C]inica] t r i a ] s revealed that roxatidine acetate, 75 mg twice daily and 150 mg at night, was highly effective in healing duodenal and gastric ulcers and in reducing ulcer pain, over 4, 6, and 8 weeks of therapy. In a l l efficacy c r i t e r i a (cure, reduction in ulcer size, and pain r e l i e f ) there was no significant difference between roxatidine acetate in a total daily dose of 150 mg, ranitidine in a tota] daily dose of 300 mg, and cimetidine in a total daily dose of 800 mg. Prevention of gastric and duodenal u]cer relapse was achieved b~ roxatidine acetate, 75 mg at night for 6 months, in about 70% of patients, as determined in open, p i l o t studies - a rate comparable to those reported for cJmetidine and ranitidine. Roxatidine acetate shares with ranitidine an improved safety profile when compared with cimetidine. Human pharmacology studies and short-term and long-term clinical t r i a l s have al] shown that roxatidine is an exceptionally well tolerated compound, without the ant]androgenic a c t i v i t y and interference with hepatic drug metabo]ism which have characterized cimetidine treatment. The novel structure of roxatidine acetate probably also underlies the improved safety of the compound. Krankenhaus Bethanien, MartinistraBe 44-46 2000 Hamburg 20, F.R.G.

Supported by the Robert Bosch Foundation, Stuttgart. Robert-Bosch-Krankenhaus, Abt. Gastroenterologie, 112, D-7000 Stuttgart 50/FRG

Auerbachstr.

PP 02.26

PP 02.28

PHARMACOKINETICS AND -DYNAMICS OF FAMOTIDINE IN PATIENTS WITH OESOPHAGITIS U. Gladziwa, D.R. Krishna, B. Dreuw~ N.K. Truong~ H. Mann and U.. Klotz

ROXATIDINE ACETATE: SINGL~NIGHT TIME DOSE IN THE TREATMENT OF DUODENALULCER H.G. Dammann, M. Dreyer, N. Wolf, P. M~ller, 8. Simon

The new histamine H2-receptor antagonist famotidine (fam) represents a well-studied alternative to cimetidine or ranitidine in the treatment of peptic ulcer or in patients with Zollinger-Elllsonsyndrome. However, so far only limited data are available about fam's clinical efficacy and pharmacokinstic properties in patients with reflux oesophagitis. Therefore we have investigated these two aspects In such individuals. Six patients (age range 25-79 years, normal kidney function) with endoscopioally proven oesophagitis of grade I to II received Initially an Intravenous bolus of 20 mg of ram followed on the subsequent days by an individual but fixed oral maintenance treatment (20-160 mg/die) for 6 weeks. Prior to the start of the study two glass pH-electrodes were placed nasally in the distal oesophagus and one in the fundus. The intragastric pH was measured using continuous long-term pH-monitoring (Synectics Medical) for 24 h. During this period multiple blood samples were drawn in order to ana!vze plasma levels of faro by a specific HPLCassay and to detect any relationships between plasma concentrations and intragastral pH profile. Following the iv-bolus ram was eliminated with a half-life of 4.2 _+ 2.3 h (mean • SD) and a total plasma clearance of 324 • 49 ml/min; steady state volume of distribution averaged 1.38 -*- 0.71 I/kg. All these data are comparable to those obtained in healthy subjects. About 40 rain after the injection an intragastric pH-value of 4 was achieved and remained above this level for 4 to 6 h. No clear association between the individual pharmacokinetic and -dynamic data was obvious. The oral treatment with faro resulted only in some improvement of the oeaophagitis which might be due to the relative short treatment period of 6 weeks.

Medical Clinic, Technical University Aachen, D-5100 Aachen/FRG

Roxatidine acetate is a newly developed inhibitor of gastric acid secretion with potent Hz-receptor blocking a c t i v i t y . Roxatidine is characterized by an unique .chemical structure with a piper]dine and benzo]e ring system, an unusually high b i o a v a i l a b i l i t y (>90%) and an outstanding long terminal h a t f - l i f e . We conducted a 4 week, double blind, randomized multicenter (n:37) study in Austria, Belgium, Finland, France, Netherlands and West-Germany. 523 patients with endoscopically proven duodenal ulcers were randomly allocated to treatment with either roxatidine 150 mg nocte or cimetidine 800 mg nocte for 2-4 weeks in a prospective manner. The two groups were similar with regard to age, sex, duration of ulcer disease, smoking habits etc. After 2 weeks treatment 90/248 (36.3%) healed on roxatidine and 89/256 (34.8%) on cimetidine. The corresponding healing rates after 4 weeks were 80.6 and 81.6%. At each time there was n6 statistical difference between the roxatidine and cimetidine groups. There were no differences between the treatment groups in ulcer pain r e l i e f . Krankenhaus Bethanien, MartinistraBe 44-46 2000 Hamburg 20, F.R.G.

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PP 02.31

OMEPRAZOLE PHARMACOKINETICS OF SINGLE AND REPEATED ONCE DAILY ADMINISTRATION OF 10, 20

TEUCRIUM POLIUM EXTRACT : PART I. ITS ANTI-

AND 40 MG AS ENTERIC COATED GRANULES T. Andersson, C. Cederberg, A. Heggelund and P. Lundborg Twelve healthy males were given i0, 20 and 40 mg omeprazole as enteric coated granules for five days and as single intravenous doses. Blood samples were collected for 24 hours on days 1 and 5 and also following the single intravenous administrations. The study was performed as an open cross-over trial consisting of three study periods (one for each dose) with one week's washout in between. The results from the iv doses indicate nonlinear kinetics in the d--ose range 10-40 mg; CL was decreased by 15% from 467 ml/mln for the 10 mg dose to 404 ml/min for the 40 mg dose and corresponding t89 was prolonged by 17% from 0.61h to 0.71h. This small effect is indicative of enzyme saturation and/or product inhibition. The AUC of omeprazole increased proportionately wihh dose on day 1 of oral dosing. However, the results after repeated oral dosing showed nonlinearity; the AUC-values increased from day 1 to day 5 by 21, 69 and 182% for the i0, 20 and 40 mg doses, respectively. The disproportionate increase in AUC with increased dose on day 5 is probably due to decreased hepatic metabolism with chronic dosing of omeprazole. Increased absorption due to decreased intragastric acidity may also contribute. Research Laboratories, AB H~ssle, S-431 83 M61ndal, Sweden.

GASTRIC ULCER ACTIVITY. N.A.A.Twai~

~ A.A.Albdr & A.Abul-Khail.

AQueous extract of Teucrium polium Linn. ( Lsbiatae ) was broadly used in folk medicine for treatment of gastro- intestinal disturbances including peptic ulcers in Iraq and some Arab countries.In our laboratory the induction of gastric ulcer was done in starved r~ts by reserpine ( 20mg/kg i.p. ) or by stress. T. oolium ( 150mg/kg i.p.) ss a crude extract produced 50% healing of ulcers while the oral administration of the extract produced 85% healing activity of the ulcers. These results were comDared with proglumide and with salioe in control animals. Department of pharmacognosy and pharmacology, Biological Research Centre, Scientific Research Council, Jsdiriyah~ P.O.Box 237~, Baghdad- Iraq.

PP 02.30

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EFFECTS OF PHARNIACOTHERAPY WITH SUCRALFATE IN PATIENTS WITH DUODENAL AND GASTRIC ULCER

A META-ANALYSIS OF ZINC ACEXAMATE IN PEPTIC ULCER. J.E. Ba~os*, E. Jim~nez, F. Bosch*, S. Sendr6s, C. Vernetta and J.L. Galm~s Zlnc acexamate (ZAC), a new a n t i u l c e r drug, e x h i b i t s gastric antisecretory (acid and pepsinogen) and mucosal p r o t e c t i v e properties. The present study evaluates i t s clinical effectiveness using a meta-analysls of 18 published and unpublished c l i n i c a l t r i a l s comparing ZAC with placebo and He receptor antagonist drugs (H2-RAD) in peptic ulcer (PU). All studies had s i m i l a r protocols and basal c h a r a c t e r i s t i c s . The study evaluated 1042 patients, 667 were treated with ZAC, 191 with r a n l t i d i n e , 107 with clmetldine and 51 with placebo. We analysed the healing rates (with the I n t e n t i o n - t o - t r e a t method), the incidence Of associated inflammatory processes and the frequency of adverse reactions. The global healing rate with ZAC was better than with placebo [odds r a t i o (0R)=5.55; 95~ and no differences ~ppeared when compared with H2-RAD (OR=I.IOI 95%CI=0.74-1.64). When comparing healing rates by ulcer type, we obtained s i m i l a r results between ZAC and H2-RAD (gastric ulcer: OR=I.14, 95% CI=0.47-2.72; duodenal ulcer: OR=O.g7, 95~ CI=0.13-7.33). However, ZAC was better than H2-RAD in reducing associated g a s t r i t i s (0R=5.51; 95%CI=0.85-35.53) and duodenitls (0R=5.53; 95% CI=2.39-12.78). Adverse reactions frequency was similar in a l l groups, including placebo (less than 2.5%). In conclusion, ZAC is better than placebo in the treatment of PU. When compared with H2-RAD, no differences has been observed in healing rates but ZAC induces a more favourable e f f e c t in the inflammatory associated processes. Thus ZAC is a very i n t e r e s t i n g option in the treatment of PU.

In a randomized controlled clinical study the authors investigated the effectiveness and safety of sucralfate in a dose 4xlg daily, for 3-12 weeks. In a group of 68 patients with endoscopically confirmed diagnosis of duodenal or gastric ulcers the authors confirmed the favourable effect of sucralfate on the regresion of pain (average 2,9 days in duodenal ulcer and 3 days in gastric ulcers)as well as on healing of the u l c e r ( m e a n period in duodenal ulcer 22,4 days and 33,6 days in gastric ulcers)oAs compared with the effect of cimetidine 2x4OOmg daily, sucralfate proved more effectiveoWithin three weeks after sucralfate treatment 88,9% duodenal ulcers healed,after cimetidine treatment 40 %~ Within 5 weekes after sucralfate treatment all duodenal ulcers were healed,while after cimetidine treatment it took 8 weeksoSucralfate was also more effective in gastric ulcer~ After 8 weeks of sucralfate treatment gastric ulcers did not heal in 20% of patients,in cimetidine group it reflects 33,3%~ The only noted side-effect of sucralfate was mild constipationolnVestigating the often discused possible influence of sucralfate on calcium/phosphate metabolism~no serious effect was noticed in period of 3-12 weeks o~ treatment in given dose~ The above observations justify the inclusion of sucralfate among the drugs of first choice in the treatment of duodenal and gastric ulcers~ DptoOf Clinical Pharmacology,Institute for Postgraduate Study,Limbov~ 12,CS-83303 Bratislava

*Dep. Farmacol. Psiquiat. Universidad Aut6noma Barcelona, and Dep. Investigaci6n Cl~nica. Laboratortos Vifias, S.A., Torrente Vidalet, 29, 08012-Barcelona (Spain)

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MESALAZINE AVAILABILITY IN THE GUT AND SYSTEMICALLY: COMPARISON OF THREE PREPARATIONS AND SULPHASALAZINE IN MAN. E.F. Hvidberg, L.A. Christensen, J. Fallingberg, B. Jacobsen, K. Abildgaard and S.H. Hansen In order to deliver optimal amounts of 5-ASA (mesalazine, 5-aminosalicyclic acid) to affected parts of the intestines in inflammatory bowel disease, the release pattern of the preparation must be known. In 9 ileostomy patients and 12 normal subjects 5-ASA and ac-5-ASA concentrations in faeces, urine and plasma were measured after 6 days treatment with 2000 mg/day of Asacol | , Claversal| and Pentasa| , respectively, in a cross-over design. Sulphasalazine (SASP) was administered to normal subjects as a control. Feacal recovery of ac-5-ASA was greater after Pentasa compared with Asacol in ileostomy patients (p
GASTRIC MOTILITY IN MAN IS UNAFFECTED BY PARENTERAL DICLOFENACSODIUM ADMINISTRATION. G.Bassotti, C.Betti, G.Bucaneve, L.Patoia, G.Erhella, *V. Mae-esca, A.Morelli, A.Del Favero. First Dept of Internal Medicine, University of Perugia, and ~Medical Dept, Ciba Geigy, Ori~io, Italy. Recent animal investigations suggest that nonsteroidal antiinflammatory drugs (NSAID) are involved in gastric mucosal damage by increasing amplitude of gastric contractions. However, such an evidence in man is lacking. Therefore, we studied the effects of diclofenae sodium (DS), a widely employed NSAID compound in our country, on haman gastric contractile activity. Nine healthy male volunteers (20 to 30 yr old) were investigated by manometry. According to a double-blind randomized crossover design (DS, 75 im vs placebo), two paired manometric studies were carried out by a multilamen probe and low compliance infusion system. Under fluoroscopic control, the probe was positioned ~n order to have closely-spaced openings recording contractile activity from the distal antrum. After obtaining a basal adaptation period, either DS or placebo were injected, one hour before administration of a 600 kcal meal, to evaluate their influence on a physiological reproducible stimulus. Recordings were then prolonged for three hours after the meal has been assumed. Mean amplitude of gastric contractions following the meal was blindly calculated for lO-min periods. Analysis of variance (by Kruskal-Wallis test) disclosed no differences between DS and placebo administration. It is concluded that in man, at least for DS, motility alterations are unlikely to be responsible for the gastric lesions sometimes reported with this compoand.

PP 02.34

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E X C R E T I O N O F [ 1 4 C ] - A C T I V I T Y A F T E R O R A L ADMINISTRATION OF [14C]-LABELLED OLSALAZINE TO HEALTHY VOLUNTEERS

D I E T A R Y FIBRE, I N T E S T I N A L F A E C A L BULKING.

B. S j ~ q u i s t , B. O d l i n d a n d E. L u n d ~ n Olsalazine is a new drug designed for treatment of ulcerative colitis. In c o l o n t h e a z o b r i d g e is r e d u c e d b y b a c t e r i a to t h e a c t i v e c o m p o u n d 5 - a m i n o s a l i c y l i c acid. T o s t u d y t h e r e c o v e r y o f o l s a l a z i n e in m a n an one gram dose of the drug was administered with [ 1 4 C ] - l a b e l l e d o l s a l a z i n e as a tracer. The drug was administered to six h e a l t h y v o l u n t e e r s as a s o l u t i o n p.o. U r i n e and faeces were collected during 7 days. The faeces samples were combusted and [14C]-labelled CO 2 was counted. T h e [14C] in urine samples were measured by liquid scintillation counting directly. The total recovery of the administered dose was 98• (mean• range 92-i05%). The m a j o r p a r t o f t h e dose, 75%, w a s f o u n d in faeces and 23% was recovered in urine. W i t h i n t h e f i r s t 24 h r s 7 4 % of t h e d o s e h a d b e e n r e c o v e r e d a n d w i t h i n 48 h r s 9 0 % h a d been excreted. In e a r l i e r s t u d i e s u s i n g l i q u i d c h r o m a t o graphic separation and UV and fluorescence d e t e c t i o n o n l y 7 0 % of t h e d o s e h a s b e e n r e c o v e r e d . T h i s is p r o b a b l y d u e t o d i f f i c u l ties to recover 5-aminosalicylic acid or other labile metabolites from faeces. In c o n c l u s i o n , this study shows that olsalazine or its metabolites are not retained in the human body after a single oral administration. Pharmacia LEO Therapeutics AB, Dept. of B i o a n a l y s i s a n d K i n e t i c s , S - 7 5 1 82 U p p s a l a , Sweden.

I.M. R.E.

Baird, J o a n Lister.

Fowler,

TIMES

AND

Staniforth

and

TRANSIT

D.H.

The aim of the s t u d y was to investigate the r e l a t i o n s h i p b e t w e e n small and large bowel t r a n s i t times, faecal bulking and dietary fibre intake in subjects consuming a standardised low c~lorie liquid diet. ( C a m b r i d g e Plan) Obese, but otherwise healthy~ subjects on this r e d u c i n ~ diet of 1 3 8 Mj per day as t h e i r sole n u t r i t i o n a l s o u r c e were used. A three way c r o s s - o v e r d e s i g n with 5 day test periods separated by 3 day washouts was utilised. S u b j e c t s s u p p l e m e n t e d their liquid diet with either 0~, 30.5~ or 21~ of Fiberform (Testa triticum tricum, min. 80% dietary fibre) daily in the form of a s u s p e n s i o n ( F i b e r f o r m Mix, T r i c u m AB, Sweden) taken in three divided doses allocated randomly. 0ro-caecal and colonic transit times were measured usin~ the sulphasalazine/sulphapyridine method combined with low intensity radiography using a radio-opaque marker technique. Total daily f a e c a l o u t p u t was c o l l e c t e d and weighed. The a d d i t i o n of the dietary fibre colonic transit time and increased b u l k in a dose-related manner but e f f e c t on small bowel t r a n s i t time. West M i d d l e s e x Middlesex, TW7

University 6AF, UK.

reduced faecal had no

Hospital~Isleworth~

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A N E F F I C A C Y S T U D Y OF A G U A R G U M F O R M U L A T I O N ON GASTRIC EMPTYING, ABDOMIMAL RELATED SYMPTOMS AND GLUCOSE ABSORPTION PERFORMED ON HEALTHY HUMAN VOLUNTEERS

LACTOBACILLUS GG IN THE PREVENTION OF ANrFIBIOTIC ASSOCIATED DIARRHEA H. Vapaatalo, S. Salminen, S. Siitonen & S. Gorbach

Ph. P a p a l e x i o u , A. P a p a l e x i o u .

N. P u t t e m a n s ,

P. A n d r @ ,

T h e e f f e c t s o f g u a r g u m on the g a s t r i c e m p t y i n g p r o c e s s , the g l u c o s e t o l e r a n c e t e s t a n d the f e e l i n g s o f g a s t r i c r e p i e t i o n a n d h u n g e r h a v e b e e n s t u d i e d in h u m a n normal volunteers. The results have shown that despite a feeling of gastric repletion, the gastric emptying time after a liquid m e a l is n o t s i g n i f i c a n t l y i n f l u e n c e d b y g u a r gum. T h e p l a s m a g l u c o s e c u r v e in the g l u c o s e tolerance test shows lower values and a more flat shape under guar gum administration. The physiopathologic implications of these f i n d i n g s in w e i g h t r e d u c i n g d i e t s a r e d i s c u s s e d .

HSpital Moli~re - Institut Longchamp, Av. W. C h u r c h i l l 255, B - I I 8 0 B r u s s e l s

PP 02.38 THE HUMAN BUCCAL ASSAY: A TEST FOR G A S T R O I N T E S T I N A L I R R I T A T I O N P O T E N T I A L OF DRUGS? K. H. A n t o n i n and P. R. B i e e k The a b i l i t y of drugs, such as NSAIDe to damage g a s t r o i n t e s t i n a l m u c o s a is of great c l i n i c a l i m p o r t a n c e . To define the g a s t r o i n t e s t i n a l i r r i t a t i o n p o t e n t i a l , a test u s i n g b u c e a l m u c o s a of h e a l t h y s u b j e c t s has been d e v e l o p e d r e c e n t l y (V. Place, Clin. Pharmacol. Ther. 43, 233, 1988). Drugs in a q u e o u s gel f o r m u l u were p l a c e d in p l a s t i c cups and a p p l i e d for 60 min to the m u e o s a of the lower lip and the e f f e c t s were m o n i t o r e d . Two mg and 50 mg d i e l o f e n a c s o d i u m (DS)/250 mg gel and 50 mg d i e l o f e n a c free acid (DFA)/250 mg gel were i n v e s t i g a t e d in six young, h e a l t h y v o l u n t e e r s . To test the p o w e r of p r e d i c tion, the b u e o a l assay results were c o m p a r e d in the same s u b j e c t s with g a s t r o s c o p i e f i n d i n g s after t r e a t m e n t for 2 w e e k s w i t h 50 mg DS t.i.d. or placebo. Lesions of the b u c c a l and g a s t r i c m u c o s a were graded u s i n g rating scales. Results: buceal irritation gastroscopie index score placebo i.i + 1.2 0.8 ~ 0.8 DS 2 m g / 2 5 0 mg 1.2 ~ 0.9 50 rag/250 mg 2.7 ~ 0.3 3.5 ~ 2.9 DFA 50 m g / 2 5 0 mg 1.3 + i.i The v o l u n t e e r s showed no or only m i n i m a l b u c e a l i r r i t a t i o n s after p l a c e b o , 2 mg die lofenac sodium, and 50 mg d i c l o f e n a c free acid. U l c e r a t i o n s were seen in all v o l u n t e e r s a f t e r 50 mg d i c l o f e n a c sodium. H o w e v e r , t h e r e were only sl'ight g a s t r o s c o p i c changes. T h e r e was no correlation b e t w e e n the results. It is c o n c l u d e d that the b u c c a l assay is only u s e f u l to test c o n t a c t i r r i t a t i o n u n d e r most u n f a v o r a b l e c o n d i t i o n s . It does not p r e d i c t the g a s t r o i n t e s t i n a l i r r i t a t i o n p o t e n t i a l of drugs. Human P h a r m a c o l o g y I n s t i t u t e , C I B A - G E I G Y GmbH, W a l d h 6 r n l e s t r . 22, D~7400 T ~ b i n g e n , FRG

A newly isolated Lactobacillus strain GG has been indicat e d t o survice gastric conditions and also colonize intestinal tract at least temporarily. A series of studies was conducted in healthy human volunteers to test the effects of Lactobacillus GG fermented milk products in the prevention of penicillin, ampicillin and erythromycin associated diarrhea. The antibiotics were taken three times daily. Thirty minutes after the morning and evening dose 125 ml of Lactobacillus GG fermented milk (a yoghurt type product) or pasteurized control yoghurt was ingested. In case of erythromycin, serum samples were collected for 6 hours on the first and seventh day of treatment to determine the effects of yoghurts on the absorption of the drug. After consumption of Lactobacillus GG fermented milks the microbe was Yound in fecal samples indicating colonization of the bowel of subjects taking penicillin, ampicillin or erythromycin wi~1 it daily fo[ seven days. Faecal samples indicated no Lactobacillus GG at the start of antibiotic treatment but colonization of samples taken on the 7th day of treatment. In all groups Lactobacillus GG products appeared to reduce the incidence of diarrhea and other gastrointestinal side-effects. However, subjects taking Lactobacillus GG fermented milks had more flatulence than the controls. No effect on the absorption of erythromycin was seen. It appears that Lactobacillus GG-fermented milk products may offer a dietary means of reducing gastrointestinal side-effects of con~nonly used antibiotics. Department of Biomedical Sciences, University of Tampere 33520 Tampere, Finland

PP 02.40 PHARMACOLOGICAL EFFECTS OF GOMISIN A (TJN-lOl; (+)-(6S,7S, R-biar)- 5,6,7,8-Letrahydro- 1,2,3,12- s 6,7dimethyl-lO,11-methylenedioxy-f-dibenzo[a,c]cyclooctenol) ON THE LIVER S. Takeda; Y. Ohkura M. Aburada and E. Hosoya Soje l i gna n compounds, which were i s o l a t e d from Schisandra f r u i t s , suppressed CC14-indaced l i v e r i n j u r y . Of the compounds t e s t e d , the e f f i c a c y of gomisin A was most p o ten t. We then attempted to examine v a r i o u s e f f e c t s of gomisin A (GA) on the l i v e r . ( 1 ) 6A showed an i n h i b i t o r y e f f e c t on l i v e r i n j u r i e s in duced by h e p a t o t o x i c c h e R i c a l s . 6A a l s o prevented ilmun o l o g i c a l l y induced acute h e p a t i c f a i l u r e . (2) 6A inc r e a s e d the r e g e n e r a t i o n of the l i v e r and improved the serum r e t e n t i o n r a t e of BSP a f t e F ! p a r t i a l hepatectomy in both nornal and CC14-induced chronic l i v e r i n j u r y . (3) GA suppressed the e l e v a t i o n of serum t r a n s a m i n a s e s and inc re a s e of l i v e r 4-hydroxyprol i ne c o n t e n t in CCl4-induced chronic l i v e r i n j u r y . (4) Regional h e p a t i c blood flow Was i nc re a s e d by GA. (5) GA s i g n i f i c a n t l y i n h i b i t e d both the hemolysis induced by heat or hypotonia and the r e l e a s e of l i v e r lysosomal h y d r o l a s e s . (fi) The i n f l u x of calcium i nt o he pa t oc yt e s and the leakage of t r a n s a m i n a s e s fro= them which were induced by calcium ionophore A-23187 was i n h i b i t e d by GA. Conclusion: GA p r o t e c t s h e p a t o c y t e s from c y t o t o x i c i t i e s , a c c e l e r a t e s the l i v e r r e g e n e r a t i o n a f t e r p a r t i a l hepar e c t o r y , s uppre s s e s the p r o l i f e r a t i o n of l i v e r f i b r o s i s , and i n c r e a s e s h e p a t i c blood flow. And a l s o the eytoprot e c t i v e e f f e c t of GA on the l i v e r c e l l i n j u r y may be rel a t e d to a s t a b i l i z a t i o n of plasma =elhranes and a depression on e x c e s s i v e calcium i n f l u x . Research I n s t i t u t e for Pharmacology, TSUMURA & r Aaiiachi, I n a s h i k i - g u n , I b a r a k i , 300-11 Japan

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DOSE RELATED INHIBITION OF GALLBLADDERCONTRACTIONBY THE CHOLECYSTOKININ INHIBITOR MK-329 G.A. VerDooten, R.A. Giuliano. A.P. Buntinx*, P. Blockx, E. Stab] , B. Gertz and M.E. De Broe MK-329 is a nonpeptidal peripheral cholecystokinin receptor antagonist. The drug was administered for 10 days in a double-blind placebo-controlled study to six panels (A-F) of healthy male volunteers. The treatment scheme is l i s t e d in the table. Meal-induced gallbladder contraction was studied at the expected peak (2 hours postdose on Day 4) and treugh (12 or 24 hours postdose on Day 11) concentrations. 60 minutes before a l i q u i d standard meal, subjects received an IV i n j e c t i o n of 5 ~Ci 99mTc-lminodiacetic acid (5 mg). Scintigraphic measurements of the amount of tracer remaining in the gallbladder were performed at 15 minute intervals for up to 2 hours a f t e r the meal. In the table are l i s t e d the means of the percent of counts remaining in the gallbladder at the 60-minute postmeal time point (maximal contraction).

SERUM BILIRUBIN LEVELS IN HEALTHY VOLUNTEERS K. Wareham and C. Broom We observed that a large proportion of our healthy volunteers had r e l a t i v e l y high b i l i r u b i n concentrations and reviewed, r e t r o s p e c t i v e l y , recent b i l i r u b i n levels in this population. Volunteer f i l e s were scrutinized and the most recent values for b i l i r u b i n were used for this review. Where a v a i l a b l e , two values were taken, one fasted, one non-fasted. All samples were p r i o r to drug exposure. The data was analysed by sex, fasted and non-fasted. The t o t a l data were then combined (197 male / 132 female values). Median b i l i r u b i n concentration in pmol/L (and 98th percentiles) were overall 9 (26); males 10.5 (26.1); females 7.5 (26); fasted 9 ( 2 3 ) and non-fasted 9 (26.4). ALT, AST and Gamma GT were within the reference range. The f r e quency d i s t r i b u t i o n of serum b i l i r u b i n was skewed to the r i g h t agreeing with data from Bailey et al (1977). The conventional reference range for b i l i r u b i n concentration is usually quoted as up to 17~mol/L. Failure to reccgnise the skewed d i s t r i b u t i o n may mean this l i m i t is too low. An upper l i m i t of 17pmol/L would place 9% of our studied volunteer population outside this reference range. Do healthy volunteers with high b i l i r u b i n levels merely constitute the upper l i m i t of the normal skewed range, or do they have G i l b e r t ' s Syndrome? Since reduced drug clearance has been demonstrated following paracetamol (Douglas, 1978) and tolbutamide ( C a r u ] l i , 1976) in G i l b e r t ' s Syndrome further investigation of subjects with elevated b i l i r u b i n levels may be indicated. Bailey A et al. Lancet I: 931, 1977. Douglas A P e t a l . Europ.J.Clin.Pharmacol. 13: 209-212, 1978. Carulli N e t a l . Gut 17: 581-587, 1976. Smith Kline & French Research Ltd., The Frythe, Welwyn, Herts., AL6 9AR, U.K.

Pa,el (n)

Dose% of counts remaining in (mg) gallbladder at 60 min postmeal Peak (Day 4) Trough (Day 11)

placebo (8) A (5) i qd B (5) 1 bid C (5) 2.5 qd D (5) 2.5 bid E (5) 5 qd F (5) 5 bid

11.5 -+ 6.8 25.8 • 15.4 not done 42.0 i 31.7 50.6 -+ 22.5 70.6 _+ 20.3 79.0 + 29.3

11.9 36.4 39.2 38.6 69.4 64.8 51.4

• • • • • • •

6.2 20.5 23.1 19.4 31.0 27.0 30.7

In conclusion, meal-induced gallbladder contraction is antagonized by MK-329 in a dose related manner. Departments of Nephrology and Nuclear Medicine, University of Antwerpen, W i l r i j k s t r a a t I0, B-2520 Edegem and *Merck Sharp & Dchme Research Laboratories, West Point, Pennsylvania 19486.

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S T O R A G E C A P A C I T Y OF H U M A N G A L L B L A D D E R F O R DRUGS DIFFERING IN T H E I R P H Y S I C O - C H E M I C A L PROPERTIES T. G r a m a t t ~ B. T e r h a a g and K. F e l l e r It was to e x a m i n e tne g e n e r a l assumption that all d r u g s e x c r e t e d by b i l e are c o n c e n t r a t e d in the g a l l b l a d d e r ( g b ) . F o r t h i s end, in 21 p a t i e n t s underwent cholebystectomy, drug concentrations were d e t e r m i n e d s i m u l t a n e o u s l y in h e p a t i c bile (hb), gb-bile and plasma. Drugs choosen differ markedly in their properties (acid/base, pKa, l i p i d s o l u b i l i t y = ls, and w a t e r s o l u b i l i t y = ws): S u l f a m e r a z i n (S), P h e n a z o n (P), P h e n y t o i n (pn). All d r u g s w e r e c o n c e n t r a t e d in gb r e g a r d i n g hb: S 3.4-, P 2.0-, P h 4 . 0 - f o l d . The c o n c e n t r a t i o n ratios g b - b i l e : b l o o d of the f r e e (permeable) f r a c t i o n s of the d r u g s were: S 5 . 5 - 1 6 . 6 , P 1.01.3, Ph 0.8-1.7; that means: only S reaches higher concentrations in the gb t h a n in blood. D i f f e r e n t f i n d i n g s for the d r u g s are i n t e r p r e t e d as a consequence of the insufficient p e r m e a b i l i t y p r o p e r t i e s of S ( l o w e s t Is of the drugs tested as well as very low ws). In contrast, P with m o d e r a t e Is a n d the highest ws-v~lue and Ph with the highest Is can p e n e t r a t e t h e g b - m u c o s a r a p i d l y and, hereafter, the c o n c e n t r a t i n g e f f e c t of the gb is adjusted to unity. Moreover, taking into account the l i m i t e d s t o r a g e v o l u m e of the gb, it seems not correct - from a pharmacoklnetic viewpoint to s p e a k g e n e r a l l y f r o m the gb as a c o v e r e d pool of r e l e v a n t a m o u n t s of drugs, r e s p o n s i b l e , e.g. for second peak phenomena. I n s t i t u t e of C l i n i c a l P h a r m a c o l o g y , M e d i c a l A c a d e m y D r e s d e n , F i e d l e r s t r . 27, G D R 8019 Dresden

EFFECTS OF TRYPSIN INHIBITORS AND A XANTHINE OXIDASE INHIBITOR ON DEVELOPMENT OF CHRONIC PANCREATITIS-LIKE LESIONS IN WBN/Kob RATS. J.H.Kim, K.Ohashi, H.Hara, R.Aso, T.Akimoto and K.Nakama The effect of trypsin inhibitors and a xanthine oxidase inhibitor on the prevention of pancreatic lesions in WBN/Kob rats, a spontaneous model of chronic pancreatitis, was determined as follows: 1.20,000 U/body/day urinastatine, an urinary trypsin inhibitor, was given ip to 8-12 week-old rats prior to development of initial pancreatic lesions. At 12 weeks no pathological changes occurred in either urinastatine or control groups~ At 24 weeks, after cessation of drug,the pancreatic parenchyme was more reserved in urinastatine than in non-treated group. 2. i00 mg/kg/day oral camostat, a synthetic trypsin inhibitor, was given at 8-15 weeks. Pancreatic lesions did not develop in this qroup whereas typical pancreatitic lesions appeared in controls. PFD levels of camostat group post-treatment(16 weeks)were significantly higher than those at pretreatment(8 wks) (99.0%~ 6.11;50.8%~ ll.8,p
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USE OF WBN/Kob RATS, SPONTANEOUS OCCURRING MODELS OF CHRONIC PANCREATITIS, FOR EVALUATION OF ANTI-CHRONIC PANCREATITIS AGENTS. K.Ohashi, J.H.Kim, F.Takahashi, H.Hara, R.Aso, T.Akimoto and K.Naksma.

testosterone lowering agents(3mg/kg LH-RH)and depressors of active oxygen (100mg/kg allopurinol,SOD,Catalase). Camostat and allopurinol applied between 8-15 weeks were as effective as estradiol in prevention of pancreatic lesions. Thus, WBN/Kob is a useful model for drug evaluation of anti-chronic pancreatitis agents. Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113, Japan.

EFFECT OF INDUCTION OF CYTOCHROME P450IA1 ON CYTOTOXICITY OF ACETAMINOPHEN IN CONTINUOUS HUMAN LIVER CELL LINES. E.A. Roberts. K.C. Johnson. A. Cribb. and S.P. Spielber~ Acetaminophen (APAP) hepatotoxicity occurs when cellular detoxificatios mechanisms are inadequate for the amount of toxic intermediates generated via cytochromes P-450. The role of induction of cytochromes P-450 in increasing APAP hepatotoxicity is unclear. Early studies showed that methylcholanthrene (MC) treatment increased APAP hepatotoxicity in rodents. Cytochrome P450IA1 induction by MC-type compounds is mediated via the Ah receptor, which we have identified in the continuous human liver cell lines Hep G2, Mz-Hep-1 and SK-Hep1. The Ah receptor in Mz-Hep-1 cells is more abundant and has higher apparent binding affinity for ligand than Ah receptor in Hep G2 cells. The A_A_h._receptor h in SK-Hep-1 cells may be defective as induction of aryl hydrocarbon hydroxylase (AHH) activity by polycyclicaromatic hydrocarbons does not occur in SK-Hep-1. To assess APAP hepatocytotoxicity in continuous liver cell lines, we modified invitro methods for measuring drug metabolite cytotoxicity first developed with human lympbocytes as target tissue (SP Spielberg, J Pharmacol Exp Ther 1980; 213:395); death of liver cells in culture was quantitated spectrophotometrically with the tetrazolium dye MTT. APAP hepatocytotoxicity (concentration range 0.25-15 mM) was measured with and without prior incubation of cells with benz[a]anthracene (BA), a potent inducer of cytochrome P450IA1. The concentration of BA used was the EC50 for AHH induction in each cell line (15 uM for SK-Hep-1). Sequential incubations with BA and APAP were each for 24 hours. Results: BA pre-treatment increased APAP hepatecytotoxicity in Mz-Hep-1 so that % cell death at 1 mM APAP with induction was similar to that at 10 mM without induction. APAP toxicity in Hep G2 and SK-Hep-1 was equivalent with and without BA pre-treatment. These findings illustrate the diversity of effect of cytochmme P-450 induction on drug hepatotoxicity in humans. For cytochrome P450IA1, differences in Ah receptor may be important in determining this effect. Division of Clinical Pharmacology & Toxicology, The Hospital For Sick Children Research Institute, 555 University Avenue, Toronto, Ontario, M5G 1X8, CANADA.

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Determination of the effect of anti-chronic pancreatitis agents has been hampered by the lack of a suitable chronic model. Spontaneous chronic pancreatitis-like syndrome was found in male W'istar Bonn Kobcri (WBN/Kob) rats which manifest diabetes after 9 months. (Acts diabet lat :22,335,1985 ). Histopathologic examinations revealed a distinct infiltration of inflammatory cells with interstitial edema in the acini at 3 months, followed by fibrotic exudation throughout the pancreas with aging. The only abnormal exocrine pancreatic function test detected was lower levels of urinary BT-PABA excretion in Pancreatic Function Diagnostant (PFD). Pancrestic lesions appeared only in male WBN. We discovered that estrogen prevented the development of these lesions. This study was designed to determine the suitability of this rat as a model for the evaluation of anti-chronlc pancreatitis agents. The control agent was i0 ~ g or 40 g estradiol. We compared the effects of trypsin inhibitors ( 2000 u urinastatine, 100mg/kg camostat),

F U R A F Y L L I N E IS A POTENT AND S P E C I F I C I N H I B I T O R OF C Y T O C H R O M E P 4 5 0 I A 2 IN M A N A R Boobis, D Sesardic, B Murray, S Murray, J Segura I and D S D a v i e s F u r a f y l l i n e is a m e t h y l x a n t h i n e that has b e e n shown to inhibit the o x i d a t i o n of c a f f e i n e in m a n in vivo. Caffeine elimination is increased by cigarette smoking, s u g g e s t i n g that f u r a f y l l i n e m i g h t i n h i b i t polycyclic aromatic hydrocarbon-inducible forms of P450 in man. This has now b e e n i n v e s t i g a t e d in vitro with m i c r o s o m a l f r a c t i o n s of h u m a n tissue. The effects of furafylline were determined on o x i d a t i o n p a t h w a y s c a t a l y s e d p r i m a r i l y by one f o r m of P450. These were hepatic debrisoquine 4hydroxylase (P450IIDI), coumarin 7-hydroxylase (P450coh), high affinity phenacetin O-deethylase (P450IA2), p-nitrophenol hydroxylase (P450IIEI), benzphetamine N-demethylase (P450IIBI), ethylmorphine N-demethylase (P450IIIA), aryl hydrocarbon hydroxylase (several forms) and placental aryl hydrocarbon hydroxylase (P450IAI). F u r a f y l l i n e was a potent n o n - c o m p e t i t i v e i n h i b i t o r of p h e n a c e t i n O - d e e t h y l a s e , with a K~ of 0.7 ~M (ICs0 0.07 ~M). The ICs0 for all of the other r e a c t i o n s was > 500 ~M. Thus, furafylline is a h i g h l y specific inhibitor of P 4 5 0 I A 2 in man. Of some i n t e r e s t was the f i n d i n g that i n h i b i t i o n was noncompetitive. This is due p r e s u m a b l y to ligand f o r m a t i o n b e t w e e n a N - a t o m and the h a e m iron of P450. However, this would not explain the specificity, which could be due to an initial interaction with the substrate binding site, b r i n g i n g the l i g a n d into p r o x i m i t y w i t h the haem. F u r a f y l l i n e a p p e a r s to p r o v i d e a p o w e r f u l m e a n s of determining the contribution of P450IA2 to the o x i d a t i o n of f o r e i g n c o m p o u n d s in man. Department of Clinical Pharmacology, Royal P o s t g r a d u a t e M e d i c a l School, L o n d o n WI2 0NN, U K and iInstitut M u n i c i p a l d ' I n v e s t i g a c i 6 M~dica, Barcelona, Spain.

ENTEROHEPATIC CYCLING OF MEXILETINE AND ITS METABOLITES IN HUMAN? W. Popfawska, D, Pa,czkowski, Z. Sadowski, M. Filipek, D. Sitkiewicz The concentrations Of mexiletine (MEX) and its metabolites: p-hydroxymexiletine (p-OHMEX) and hydroxymethylmexiletine (OHMeMEX) were measured by HPLC in serum and feces. In 6 volunteers and 8 patients with ventricular arrhythmias, single i.v. or p.o. dose of 200 mg of mexiletine was given. Samples of the blood were collected before and at 0,5, 1, 1.5, 2, 3, 4, 6, 8, 12, 24 hours after drug administration. Additionally for 4 patients blood samples were also collected after 16, 18and 20 hours. Mean concentration-time data for the last group after oral dose are as follows: time MEX (ng/ml) p-OHMEX OHMeMEX

0.5 1.0 1.5 2.0 3.0 4,0 8.0 8.0 10 12 16 18 20 24 45 248 420 621 764 700 678 650 726 501 430 553 128 88 96 182 243 298 265 212 275 120 95 135 78 65 80 128 520610682651 549628 475381 488 110 72

(-) concentration less than 50 ng/ml. Concentration-time data Obtained for each subject after oral administration shown similar character. Double-peak phenomenon for MEX and its metabolites was observed. In 4 cases with mor e frequent sampling the third peak at 18 hour after dose was easily identified. Double-peak phenomenon on concentration-time profiles after i.v. dose of MEX was also observed. Mexiletine was identified in all samples of feces after p.o. and kv. administration of MEX. Obtained results seem to suggest enterohepatic cycling of mexiletine. It may be important for pharmacokinetics of th e drug. National Institute of Cardiology, Department of Noninvasive Diagnostics ul. Alpejska 42, 04-628 Warszawa.

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IN V I T R O AND IN V I V 0 B I O T R A N S F O R M A T I O N IN HUMAN LIVER DISEASES C O M P A R I S O N TO HISTOLOGICAL CHANGES H. Kraul, J. T r u c k e n b r o d t , G. M a c h n i k and A. Hoffmann To e s t i m a t e c y t o o h r o m e P - 4 5 0 - d e p e n d e n t b i o t r a n s f o r m a t i o n in v i t r o the 7 - e t h o x y c o u m a r i n 0 - d e e t h y l a s e a c t i v i t y (ECOD) was m e a s u r e d in 5 4 l i v e r b i o p s y s a m p l e s of p a t i e n t s w i t h c h r o n i c l i v e r d i s e a s e s . The e n z y m e a c t i v i t y s h o w e d a w i d e range. The m e a n v ~ I u e s were d e c r e a s e d in h e p a t o s i s (n=17, !9.i + 5.0 p m o l / m i n " mg p r o t e i n ) , c h r o n i c h e p a t i t i s (nZ23, 1 4 . 0 + i.9 p m o l / m i n , mg protein, i}<0.05) and l i v e r c i r r h o s i s (n=6, ~ 6 . 2 + 8 . i p m o l / m i n 9 mg p r o t e i n ) c o m p a r e d to n o r m a l T i v e r h i s t o l o g y (n=8, 3 3 . 4 Z 9 . 2 p m o l / m i n . mg p r o t e i n ) . The E O O D c o r r e l a t e d to c h a n g e s of some h i s t o l o g i c a l features: i n t r a a c i n a r fibrosis, p a r e n c h y m a l n e c r o s i s and s t r u c t u r a l t r a n s f o r m a t i o n to c i r r h o t i c l i k e pattern (p<0.05). In i6 p a t i e n t s the k i n e t i c s of m o d e l s u b s t a n ces in v i v o as well as the in v i t r o b i o t r a n s f o r m a t i o n was d e t e r m i n e d . The c o r r e l a t i o n b e t w e e n E C O D and the m e t a b o l i s m of m e t a m i z o l as p a r a m e t e r of the a c t i v i t y of c y t o c h r o m e P - 4 5 0 p ~ was s t a t i s t i c a l l y s i g n i f i c a n t c a l c u l a t e d by ~ l i n e a r r e g r e s s i o n a n a l y s i s . C a f f e i n e as p a r a m e t e r of the a c t i v i t y of c y t c c h r o m e P - 4 5 0 M C s h o w e d no c o r r e l a t i o n . T h e r e is a d i s t i n c t c o n n e c t i o n b e t w e e n E C O D andboth d e s t r u c t i o n of l i v e r s t r u c t u r e and the a c t i v i t y of c y t o c h r o m e P - 4 5 0 p B . F r i e d r i c h - S c h i l l e r - U n i v e r s i t ~ t J~na, I n s t i t u t f~r K l i n i s c h e P h a r m a k o l o g i e , B a c h s t r a S e 18, D D R - 6900 g e n a -

BLOOD UNCHANGEDAND CONJUGATEDPROPRANOLOLAND 4-HYDROXY~ROPRANOLOL LEVELS OBSERVEDAFTER ADMINISTRATION OF SUSTAINED RELEASE FORMULATIONS. A. Roux, C. Walle, M. Benoist, M.S. Boutin and B. Flouvat. Three primary pathways account for the f i r s t pass metabolism of propranolol (P) : glucuronidation, side-chain o x i dation and ring oxidation. Interindividual v a r i a b i l i t y in oral clearance of P is function of the rate of absorption which affects mainly the ring oxidation metabolism, resulting in the formation of 4-OH propranolo] (40HP). 40HP, pharmacologically equipotent to P, is glucuro- and sulphoconjugated. This study was realized a f t e r a single oral administration of two equivalent slow-release propranolol formulations : Inderal (LA) 160 mg and Propranolo] (SR) 160 mg, to s i x healthy volunteers. The urinary ratios of de~risoquine~40H debrisoquine were between 0.30 and 3.9 (m• = 1.13 ~ 1.36). Blood samples were drawn during 30h a f t e r administration and collected on ascorbic acid. Blood P, 40HP and t h e i r conjugates (PC, 40HPC) concentrations were measured by HPLC. Conjugates were hydrolyzed with glucuronidase-sulfatase p r i o r to extraction. For a l l substances, tmax was reached at the 5th hour. The Cmax of P were 24.7 • 19.4 ng/ml (SR~ and 23.2 • 1~.2 ng/m] (LA), the values for 40HP being 4.8 - 2,5 and 4.4 - 1.1 ng/ml. The r a t i o of unchanged P/4OHP AUCO-30 were 7.2 • 7.6 (3.0 to 22.7) (SR) and 7.5 ~ 8.8 (2.6 to 25.3) (LA) and was in r e l a t i o n to the debrisoquine r a t i o . The blood PC Cmax were 3.8 • 1.9 (SR) and 3.6 • 1.5 (LA) times higher than that of unchanged drug ; the values for 40HPC were 16.7 • 6.5 (SR) and 15.3 • 3.7 (LA). The blood ratios of P/PC and P/(4OHP+4OHPC) were 0.28 0.13 and 0.32 • 0.29 respectively, showing equivalence of these two metabolic pathways. These results were s l i g h t l y d i f f e r e n t from those obtained in plasma samples a f t e r a 80 mg conventional propranolol (0.19 : 0.08 and 0.11T 0.12 respectively) (Lennard, Br. J. Clin. Pharmac., 17, 679, 1984). Toxicological and Pharmacokinetic Laboratory, A. Pare Hosp i t a l , 9, avenue Charles de Gaulle, 92100 - BOULOGNE, PROGRAPHARM, 28170 - CHATEAUNEUF-EN-THYMERAIS(FRANCE).

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G l u c u r o n i d a t i o n of o x a z e p a m in p a t i e n t s w i t h h e p a t i c enc e p h a l o p a t h y . J . S o n n e , E. Juhl. F r o m the r e s u l t s of p r e v i o u s w o r k it is g e n e r a l ly b e l i e v e d , t h a t g l u c u r o n i d a t i o n , a p h a s e II m e t a b o l i c p a t h w a y , is p r e s e r v e d in liver disease. In this r e s p e c t it d i f f e r s f r o m the majority of m i e r o s o m a l l y m e t a b o l i s e d drugs. We i n v e s t i g a t e d the m e t a b o l i s m of o x a z e p a m in s e v e n p a t i e n t s w i t h s e v e r e liver d i s e a s e and nine h e a l t h y controls. O x a z e p a m is a b e n z o d i a z e p i ne m a i n l y d e p e n d e n t on m e t a b o l i s m by h e p a t i c g l u c u r o n i d a t i o n . All p a t i e n t s had b i o p s y p r o v e n alcoholic cirrhosis. Clinically they were carac t e r i z e d by c o m a g r a d e I and II, h y p o a l b u m i n e m i a , h y p o t h r o m b i n e m i a and five out of s e v e n h a d asci tes. In the p a t i e n t s the a p p a r e n t oral c l e a r a n c e of o x a z e p a m w~s 42~9 m l - m i n (38.9-68.1), which was s l g n i z l c a n t l y l o w e r t h a n t h e c o n t r o l v a l u e 74.7 m l - ~ i n - l ( 6 6 . 0 - 1 1 5 . 7 ) ; ( m e d i a n and ranqe). E l i m i n a t i o n h a l f - l i f e was 16.6h (13.1-26.0) c o m p a r e d to 6.0h (5.4-6.2) and v o l u m e of d i s t r i b u t i o n . w a s 53.2 1 ( 4 2 . 8 - 9 2 . 5 ) a g a i n s t 39.8 1 ( 2 2 . 6 54.6). The g r o u p s d i f f e r e d s i g n i f i c a n t l y w i t h r e s p e c t to b o t h v a r i a b l e s . C o n c l u s i o n : The c a p a c i t y for g l u c u r o n i d a t i o n m a y be r e d u c e d in s e v e r e d e c o m p e n s a t e d liver disease. M e d i c a l dept. B, d i v i s i o n of h e p a t o l o g y , H v i d o v r e H o s p i t a l and med. dept. F G e n t o f t e H o s p i tal, C o p e n h a g e n

USE OF METABOLITE KINETICS AS A NON-INVASIVE PROBE OF BIOCHEMICAL PROCESSES: INHIBITION OF EPOXIDE HYDROLASE BY VALPROIC ACID D.K. Robbins, S-L. Chan$, P.J. Wedlund A theoretical approach was developed to determine metabolite formation and elimination parameters in-vivo during administration of the parent drug. This concept combined nonparametric analysis of parent drug and metabolite plasma data with the assessment of the fraction of parent drug converted to the metabolite of interest by means of urinary recovery of the metabolite and its sequential products. This concept was subsequently applied to the investigation of the effect of valproic acid (VPA) on the kinetics of carbamazepine (CBZ) and its 10,11-epoxide metabolite in pediatric epileptic patients. All pharmacokinetic parameters of interest were assessed prior and after addition of VPA to the therapeutic regimen of patients stabilized on CBZ. No significant change was observed in CBZ elimination or 10,11-epoxide formation. The elimination of iO,ll-epoxide was significantly decreased during VPA co-administration with a 20% reduction in the free elimination clearance of the iO,ll-epoxide, suggesting the inhibition of epoxide hydrolase by VPA. This study confirmed the results of other investigators and demonstrate~ that the area os metabolite kinetics can be used to probe epoxide hydrolase activity in-vivo without resorting to the administration of the epoxide metabolite per so. It further suggests that metaholite kinetics may become a powerful non-invasive probe of metabolic processes in the body. (Supported by the Epilepsy Foundation of b/nerica and the CRC Unit, University of Kentucky.) College of Pharmacy, University of Kentucky, Rose Street, Lexington, KY 40536-0082.

A 148

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METOPROLOL METABOLISM BY RAT AND HUMAN LIVER MICROSOMES: EFFECT OF STEROIDS. J.M. Pepper, M.S. Lennard, G.T. Tucker and H.F. Woods. The oral clearance of metoprolol (M) is six times higher in pregnant compared to non-pregnant women (Hogstedt et al, Clin. Pharmac. Ther. 37 (1985) 688), which may be due to an increase in the activity of the 'debrisoquine P-450'. Since hepatic mixed function oxidases can be activated by steroids in vitro (Benford et al, Xenobiotiea 19 (1980) 329), we have studied the effect of a series of steroids on the oxidation of M by liver microsomes. Methgds: Liver microsomes were co-incubated with M (rat: 20 pM; human: 40 ~M) and steroid (i00 ~M, dissolved in propylene glycol) for 7 min (rat) or 15 min (human) at 37 ~ and pH 7.4. ~-Hydroxymetoprolol (HM) and O-demethylmetoprolol (ODM) were assayed by hplc. Results: Mean values for the rates of metabolite appearance under control conditions ranged from 0.90 to 1.27 (rat) and 0.25 to 0.29 (human) nmol/mg protein per incubation for HM and 0.43 to 0.56 (rat) and 1.47 to 1.66 (human) nmol/mg protein per incubation for ODM. Significant impairment (p < 0.001) of M oxidation was observed for all of the steroids. Mean (+ sd) data for the % inhibition of HM and ODM appearance (n = 4-6): Rat Human HM ODM HM ODM diethylstilboestrol 100+13 100+16 96+5 98+5 ethinyloestradiol 77~17 84~16 83~28 93~5 beta-oestradiol 37~18 48~17 no-t tested betamethasone 40+8 33+10 not tested progesterone 39~6 39~7 32+21 36+5 testosterone not-tested -~16 20~7 Conclusion: All of the steroids tested caused inhibition of M oxidation. None caused activation of metabolism, a mechanism which may be postulated to account for the pregnancy-induced increase in M clearance. University Department of Pharmacology and Therapeutics, Royal Hallamshire Hospital, Sheffield $i0 2JF, U.K.

PLASMA DEXTROMETORFEAN METABOLITES AND RELATION TO URINARy PHENOTYPING: PILOT STUDY Caturla M~C., de la Torte R.. Conaost M. and Secn~ra J. Drug Oxidation phenotyping with dextrometorphan (Dm) is usually based on urinary metabolic ratio to its metabolite(s) or on plasma levels of Dm. Elaborated methods of analysis are needed because the low levels of Dm in biological fluids. Metabolic products are present in higher amounts in both plasma and urine and criteria based only on their determination would facilitate dissemination of the test in less equiped or experienced laboratories. A study on urinary and plasmatic Dm met~bolites concentrations ha~ been carried out. METHODS 12 healthy volunteers were given Dm twice in a randomized order either in solid or liquid form. Dose was always 30 mg (85.13 ~mol) Dm hydrobromide. 15 blood samples and cumulative urine were collected over 8h. Concentrations of Dm and its main metabolites dextrorphan (D) and morphinan-3-ol (M) were measured by HPLC. RESULTS Areas under the concentration-time curves (AUC) for D in plasma were higher than 2.59 nmol.h.ml -I (up to 8.41) for i0 subjects, around 2.33 nmol.h.ml -I for one subject and lower than 0.175 nmol.h.ml -I for the remaining one. When the AUC's of M were added to those of D, the differences between the three groups were further increased. Strong inverse parallelism of plasma AUC's was found with urinary description of phenotype. Thus, the metabolic ratio between Dm and D was lower than 0.01 for first I0 subjects, around 0.1 for the intermediate one and around 0.7 for the last. Parameters related to levels of Dm metabolites in plasma may act as good indicators of oxidative phenotype. Even one single point determination in plasma of D might be an alternative to other means of phenotyping. A strong correlation between plasma D levels and metabolic classification by both urinary metabolic ratios or plasma AUC's was detectable. Best data fit was obtained by point determination at 2-3 h after Dm administration (r>0.95 at 3 h for both formulations; exponential regression). Further studies with large number of volunteers will be needed to ~stabllsh antimode values. Dept Pharmacol, Inst Mun Inv Mad (IMIM) , P. Maritim 25, 08003-Barcelona, Spain.

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METABOLIC PATHWAYS OF ETHYLMORPHINE (EM) CODEINE (COD) AND DEXTROMETHORPHAN (DM) IN HUMAN FETAL LIVER M.G. Ladona, D.J.Spalding,K.Persson,B.LindstrUm and A.Rane

IN V I T R O F O R E C A S T I N G OF DRUGS INTERACTING WITH SHORT-ACTING BENZODIAZEPINES M . - P . G a s c o n a n d P. D a y e r Liver biotransformation of m i d a z o l a m (MDZ) a n d triazolam, two short-acting benzodiazepines, is mediated by cytochrome P-450 nf, a P - 4 5 0 I I I A subfamily isozyme (Kronbach, 1989). The d u r a t i o n of a c t i o n of t h e s e d r u g s b e i n g r e l a t e d to t h e i r h e p a t i c c l e a r a n c e , we investigated, by in v i t r o s c r e e n i n g , drugs that could interfere w i t h t h e a c t i v i t y of t h e P - 4 5 0 I I I A i s o z y m e . METHODS: MDZ l'-hydroxylation in h u m a n liver mierosomes, at variable concentrations of t h e tested drug, is u s e d as p r o t o t y p e reaction. Metabolite production is monitored in supernatants by direct HPLC-UV detection (254 nm). RESULTS: Km for l'-hydroxylation is 5 ~M. Imidazole antifungics are powerful blockers of the reaction (i.e. k e t o c o n a z o l e , K i 0.2 p_M). Among other types of inhibitors are calcium channel blockers (i.e. n i f e d i p i n e , 5 ~LM?~ e r g o t alcaloids (i.e. ergotamine, 2 ~M), ciclosporine (5 ~M), caffeine (i000 ~M), erythromycin, amiodarone and levomepromazine. CONCLUSION: Oxidation rate, and thus duration of a c t i o n , of s h o r t - a c t i n g benzodiazepines is l i a b l e to v a r y g r e a t l y w h e n t h e y a r e c o m b i n e d with other drugs. Several of t h e t e s t e d d r u g s are competitive inhibitors of this reaction, suggesting that their biotransformation could be mediated b y t h e s a m e or a c l o s e l y r e l a t e d P450 i s o z y m e . Clinical Pharmacology, Geneva University Hospital, C H - 1 2 1 1 G e n e v a 4, S w i t z e r l a n d

Aseries of fetal liver microsomes were analysed for N- and 0-demethylation activities with EM,COD or OH as substrate. The liver specimens were obtained at legal abortion performed on sociomedieal indications. The 0-and N-demethylated metabolites were analysed in the incubates by high performance liquid chromatography utilizing octadecylsilane columns for COD and DM and an alkylnitriJo modified silica for EM.The limit of determination was a few ng/ml of incubation mixture for all demethylated products. The activities of the N-demethylation pathway varied between 42-1278,602567,5-163 pmol/mg/min for EM,COD, and DM respectively. These values are comparable to the adult values.A lack of the O-demethylation activity was observed for all opioids according to negative immuooblots assayes with Nab 114/2, a monoclonal (Mab) antibody against human cytochrome P-450 debrisoquine (kindly supplied by Prof.U.A. Meyer). The fetal Hlp form was immunodeteeted using a Mab PCN 2-13-I/C2 against pregnenolone 16-alpha-carbonitrile induced rat liver eytoehrome P-450 (kindly supplied by Dr. H.V. Gelboin). The laser scans values of immunadetected proteins correlated well with EM N-demethyl~tion activity (r=O.96) and with N-demethylation of DM (r=0.89) suggesting a possible role of the Hlp form in the opioid N-demethylation pathway.Analysis of the enzyme kinetics showed an estimated Km of 1.5 and 5.7 mM and Vmax of 1.33 and 4.18 nmol/mg/min For EM and COD, respectively, performed in the same fetal specimen. Midazolam (0.4mM) completely inhibited the N-demethylation of EM and COD in the investigated.livers. Our results lead to the following conclusions: I)- There is an absence of the oplaid O-demethylationpathway i.e. a lack of expression of the eytochromeP~5Odebrisoc~inein fetal life. 2)- The high opioid N-demethylationactivities are comparable to the adult values. 3)- The data support the assumption of a contribution of fetal cytochrome P-450 Hip to the opioid kLdemethylationpathway with different substrate affinity. Division of Clinical Pharmacology. University Hospital, S-75185 UPPSALA. Sweden.

A 149

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IN V I T R O F O R E C A S T I N G O F D R U G S I N T E R F E R I N G W I T H CODEINE BIOACTIVATION P. D a y e r a n d R. S t r i b e r n i C o d e i n e (Co) a n a l g e s i a is m e d i a t e d t h r o u g h its O-demethylation in morphine (Mo) by the p o l y m o r p h i c c y t o c h r o m e P - 4 5 0 d b I or P - 4 5 0 I I D I ( B i o c h e m B i o p h y s Res C o m m u n f52, 411, 1988). B y m e a n s of in v i t r o s c r e e n i n g in h u m a n l i v e r m i c r o s o m e s w e i n v e s t i g a t e d the e f f e c t on Co bioactivation of several drugs used as a n a l g e s i c s o r a d j u v a n t s for pai n c o n t r o l . M E T H O D S : E x t e n s i v e m e t a b o l i z e r m i c r o s o m e s (db 1 p h e n o t y p e ) are i n c u b a t e d w i t h Co and v a r i a b l e concentrations of the tested drug. Mo p r o d u c t i o n r a t e s are m o n i t o r e d in s u p e r n a t a n t s by HPLC - fluorescence detection. R E S U L T S : In e x t e n s i v e m e t a b o l i z e r m i c r o s o m e s Co for the p o l y m o r p h i c O - d e m e t h y l a t i o n is in [~e 200 bM range. Analgesics (paracetamol, a c e t y l s a l i c y l i c acid, d i c l o f e n a c , i n d o m e t a c i n & piroxicam) and benzodiazepines (chlordiazepoxyde, diazepam, bromazepam & midazolam) do not alter in v i t r o Mo production. Powerful i n h i b i t i o n of the r e a c t i o n is o b s e r v e d w i t h neuroleptics (chlorpromazine, thioridazine, l e v o m e p r o m a z i n e & h a l o p e r i d o l - IC50 i-i0 bM) and tricyclic antidepressants (amitriptyline, nortriptyline, imipramine, desipramine & c l o m i p r a m i n e - I 0 - i 0 0 ~M). C O N C L U S I O N : D u e to the v e r y low a f f i n i t y of Co for the polymorphic db I monooxygenase, its bioactivation in e x t e n s i v e metabolizers is l i a b l e to v a r y g r e a t l y w h e n it is c o m b i n e d w i t h a n y d r u g t h a t has h i g h a f f i n i t y for the i s o z y m e (e.g. t h e s e a n t i d e p r e s s a n t s or a n t i a r r h y t h m i c s and betablockers - K m < 50 bM). Clinical Pharmacology, Geneva University H o s p i t a l , CH - 1211 G e n e v a 4, S w i t z e r l a n d

ANTIPYRINE METABOLISM IS NOT AFFECTED BY TERBINAFINE, A NEW ANTIFUNGAL AGENT J.C. Jensen, R. Seyffer, M. Eichelbaum and U. Klotz

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EFFECTS OF DILTIAZEM (D) ON THE KINETICS AND DYNAMICS OF ENCAINIDE (E) AND ITS ACTIVE METABOLITES M.B. Bottorff, D.J. Kazierad, T.J. Hoon, R.L. Lalonde In most patients, E is metabolized to O-desmethyl encainide (ODE) which is subsequently converted to 3methoxy-desmethyl eneainide (MODE), both being more active than E. Because D has been shown to impair the hepatic elimination of several drugs, we studied the disposition of E, ODE and MODE in 8 extensive metabolizers following E 25mg PO qSH x 7 days alone and with D, 90mg PO q8H x 7 days. Serum and urine were collected for 72 hours after the last dose. Dynamics were expressed as areas under the ECG effect curve for QRS and QTc intervals. Data were compared with the Wileoxon matched-pairs test and expressed as medians (ranges). After D, the E/ODE serum AUC ratio increased from 0.025 (0-0.31) to 0.31 (0-0.47) (P<0.05), suggesting impaired O-demethylation of E. Serum ODE and MODE AUC's and ODE/MODE AUC ratios were unchanged. After D, renal clearance (CLr) of ODE increased from 69 (41-i16) ml/min to 87 (58-133) ml/min (P=0.2); MODE CLr increased from 13 (8-58) ml/min to 26 (13-54) ml/min (P
PHARMACOKIXfE~ICS AND METABOLISM OF METHOTREXATE IN THE RAT Z. H. Ai-Mustafa, Faith M. Williams and M. D. Rawlins. Although methotrexate (MPX) is an important antineoplastic and antipsoriatic agent, its use is associated with many toxic effects. Studies relating to MTX toxicity have mainly been based on measurement of plasma levels of the unchanged drug (R.G. Stoller et al, New Engl. J. Med.297: 630, 1977), but the contribution of its metabolites has not been well investigated. Thus we studied the elimination profile of unchanged MTX and also the formation and fate of its 7-hydroxy derivative (7-OH-MTX) as well as the pharmacologically active polyglutamate metabolites in the rat. Rats w e r e injected with 200mg/kg MTX intraperis and 4 animals were killed at 0.5, 1,3,5,7 and 24 hours. Tissue concentrations of MTX, 7-OH-MID<, MTX diglutamate (G2), end MTX triglutamate (G3) were determined by high performance liquid chrc~atography. MTX levels in plasma, liver, kidney and bone marrow declined biexponentially tp• e• nalf-lives=0.6 and 4.6 h) reaching low plasma levels of 0.2+0.02 ~M (~z~ntsc~m) at 24 hours. Levels of 7-0H-MIX reached peak values in plasma (4.7+2.6 pM), liver (28.5+ii.I nmol/g, wet weight), and kidney (6.9+4.1 nmol/g) at 1 hour before declining in a similar fashion as these of MTX. Hepatic, renal and bone marrow concentrations of G2 fell initially reaching steady levels ranging frc~ 20.0 to 40.0 nmol/g at 3 hours, while those of G3 (range 20.0-60.0 nmol /g) did not change significantly throughout the study. At 24 hours, MIg< pelyglutamates (G2+G3) constituted the predominant form (range 57%-100%) of all MTX-derived material detectable in the tissues. These findings indicate that FffX metabolites, particularly the pelyglutamates, may persist in the tissues in the absence of high plasma MIX levels. This may have important implications for the drug's action and toxicity. Wolfson unit of Clinical Phannacology, The University, Claremont PI., Newcastle Upon Tyne, NEI 7RU, U.K.

It is well known that antifungal drugs such as ketoconazole inhibit not only certain metabolic pathways in fungi but also drug metabolism in man. Therefore it might be possible that the new antifungal agent terbinafine has also a potential for drug interactions at the hepatic site. In order to test this hypothesis a cross-over study was performed in 8 healthy volunteers (are range 23 to 45 years) using antipyrine (10 mg/kg) as probe characterising hepatic capacity for drug metabolism. A single oral dose of antipyrine was administered prior, during a 8 days course of oral intake of terbinafine (125 mg bid) and after this treatment. In muitlple plasma (up to 32h) and urine (up to 48 h) samples antipyrine, its major metabolites 4-hydroxyantipyrine (r 3-hydroxymethylantipyrtne (3-CH3-AP) and norantipyrine (Nor-AP) were analyzed by specific HPLC-assays. In the table the most important pharmacokinetic parameters are compared of the three parts from the interaction study. mean • SD AP's p~rameters

prior to terbinafine

during terbinafine

post terbinafine

tv= (h)

11.7 - 2.5

CL (ml/h/kg) CL R (ml/h/kg) CLM to 4-OH-AP CL M to Nor-AP CL M to 3-CH3-AP

38.5 1.6 12.3 6.7 4.2

1314 • 35.4 • 1.9 • 11.5 • 5.8 • 4.0 •

12.0 39.7 2.0 12.8 7.1 4.2

• • -• •

8.3 0.6 5.7 2.3 2.4

4.0 9.9 0.8 5.7 2.2 2.4

• 2.8 • 10.5 • 1.1 --- 6.4 • 2.8 • 2.5

These data indicate that therapeutic doses of terbinafine neither inhibited nor induced the different metabolic pathways of the test drug antipyrine. Therefore it can be assumed that coadministration of terbinaitne is unlikely to affect oxidative drug metabolism and does not - in contrast to ketoconazole - interfere with biotransformation of other drugs. Supported by the Robert Bosch Foundation, Stuttgart. Dr. Margarete Fischer-Bosch-lnstitut fDr Klinische Pharmakologie, Auerbachstr. 112, D-7000 Stuttgart 50 / FRG.

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PLASMA PHARMACOKINETICS OF NICERGOLINE METABOLITES IN HEALTHY VOLUNTEERS V. Bellotti, N.G. Jannuzzo, E. More, C. Jori, A. Dubini and M. Strolin Benedetti The linearity of pharmacokinetics after nicergoline (N) administration was investigated in healthy volunteers and the pharmaeokinetie parameters of three metabolites calculated. Nine subjects received B0 and 60 mg N orally. Blood samples were taken up to 32 h after administration. Plasma concentrations of MDL (10-~-methexy-9,10-dihydrolysergol),~MNDL (l-methyl-MDL) and I-0H-MMDL (l-hydrexymethyl-MDL) were assayed by ~LC with UV detection. The linearity was estimated from plasma concentration data of the major metabolite MDL. The pharmacokinetie analysis of the thr~e metabolites was carried out ~ following the CO mg dose. The comparison of Cmex and AUC0_ ~ values of~DL after 30 and 60 mg N shewed that pharmacokineties is linear. After 60 mgN@enxvalues of MDL, I-MMDL and I-0H-MMDL were 81.2• 80.0• and 89.i• ng/ml (meaniSEM), respectively, whereas the corresponding AUC (calculated until the last measurable sample) were 909350, 2173106 and 145322 ngxh/ml. The plasma half-life (t~) value of MDL was 11.0• h. The corresponding values of I-MMDL and of I-OH-MMDL were 2.553 0.46 h and 2.42i0.27 h. In 1 volunteer I-MMDL plasma levels were much higher than in the others (AUC = 1038 ngxh/ml; t~ = 5.10 h) and I-0H-MNDL levels were particularly low (AUC = 21 ngxh/ml), probably indicating an impairment of the oxidative metabolic capacity in that subject. FarmitaliaCarlo Erba, Research and Development - Erbamont Group, Via Imbenati 24 - 20159 Milan (ITALY).

THE EFFECTS OF RIFAMPIN TREATMENT ON THE STEREOSELECTIVE METABOLISM OF HEXOBARBITAL ~ IN THE YOUNG AND ELDERLY SUBJECTS R. A. Blouin~ D. A. Smith~ M. H. H. Chandler~ S. I. Sheldlofsky~ P. J. Wedlund Previous studies have demonstrated an age-related preferential decline in the metabolism of Z-hexobarbital over d-hexobarbital in man following the oral administration of racemic hexobarbital (M. H. H. Chandler et al, Clin. Pharmacol. Ther. 43, 436, 1988). The purpose of this study was to investigate the impact enzyme induction may have on this age-related stereoselective decline. Consequently, the influence of rifampin (RMP) treatment on the stereoselective elimination of hexobarbital (HE) was studied in 6 young and 6 elderly male volunteers. Each subject received 500 mg of racemic HB before and after 14 days of RMP therapy (600 mg nightly). Serial plasma samples were quantitated by chiral HPLC. The oral clearance (CIo) of the d-enantiomer in the young, before and after induction, was 1.91 • 0.286 and 13.2 i 3.18 ml/min/k~, respectively. In the elderly, the Clo of the d-enantiomer before and after induction was 1.84 • 0.184 and 9.46 • 2.56 ml/min/kg, respectively. In contrast, the l-enantiomer's Clo in the young, before and after induction, was 15.6 • 16.4 and 559 • 327 ml/min/kg, respectively, and, in the elderly, was 10.34 • 2.96 and 222 • 98.8 ml/min/kg, respectively. The results clearly show that RMP dramatically increases the Clo of both the d- and l-enantiomers of HB in each of the age groups. The Clo of the 1-isomer was increased to a greater extent than the d-isomer (in the young, approximately 48 vs 7 fold and in the elderly, approximately 27 vs 5 fold). In conclusion, RMP treatment preferentially induces the metabolism of I-HB over d-HB in both young and elderly subjects with the magnitude of the response for both enantiomers being somewhat less in the elderly. Colleges of Pharmacy and Medicine, University of Kentucky, Lexington, Kentucky, U.S.A., 40536-0082.

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METABOLIC PATHWAYSOF THE NEWMUCOREGULATORYDRUG TASULDINE H. Verqin, H. Schimmel and P. M6rsdorf Tasuldine (2-(pyridyl-3-methylthio)-pyrimidine) is a newly developed mucoregulatory agent which normalizes the pathologically altered tracheobronchial mucin pattern in patients suffering from chronic bronchitis. The drug is absorbed from the gastrointestinal tract almost quantitatively in man and laboratory animals; the systemic avail a b i l i t y of the parent drug amounts to 40-50 % in all species investigated. Tasuldine shows a marked hepatic pre-systemic elimination, which is mainly dependent on the liver blood-flow. 8-12 renally excreted metabolites have been observed independently of the route of administration. Canine urinary metabolite fractions were isolated by preparative HPLC on Nucleosil I00-C18 and purified using preparative HPLC on Fractogel TSK-HW 40S and semi-preparative HPLC on Nucleosil IO0-NHg. 5 main metabolites, ~ i c h accounted for about 60 % of~the total dose (5 mg/kg ~"C-Tasuldine.i.v.) in canine urine, could be identified by means of 1H-NMR- and idC-NMR spectroscopy, electron impact-(EIMS) and f i e l d desorption mass-spectrometry (FDMS) and by comparison with reference compounds.- The present data show that Tasuldine is metabolized along 3 pathways: 1. pyridine-N-methylation : (M12: 2-(1-methylpyridin-3-yl-methylthio)-pyrimidine) 2. pyridine-N-oxidation and sulphoxidation (M9: (N-oxido-pyridin-3-ylmethyl)-pyrimidin-2-yl-sulfon) 3. pyridine-C-oxidation degradation and conjugation (M4: 2-(pyrimidin-2-ylthio)ethanol-O-B-D-glucuronide) (M6-1: (pyrimidin-2-ylthio)methanol-O-B-D-glucuronide. M6-2: pyridin-3-yl-O-B-D-glucuronide). The same metabolic pattern was found in the urines of all other species including man, the only exception was the metabolic product M12, which is specific for the dog.

STEREOSEIECYIVE INHIBITION OF PROPRANOIOL METABOLISM BY ANESTHESIA M. Wood, E. Whelan, I. Blair and A.J.J. wood Previous studies have shown that volatile anesthetics such as halothane are inhibitors of drug metabolism. Propranolol is administered clinically as a racemate, with the 1-isomer being i00 times more potent a 8blocker than the d-isomer. Thus the aim of the study was to determine whether halothane-induced inhibition of drug metabolism is stereoselective. We studied 8 dogs (27+2.4 kg) who had vascular catheters implanted 7 days previously on two study days. On the first day, 40 mg racemic propra~olol was infused into the portal vein when the dogs were a w a ~ and again 24 hr later during halothane anesthesia (2.0 MAC). Blood samples were taken over the next 4 hr for the measurement of d and l-propranolol concentrations, by HPIC following derivitization with (-) - m e n t h y l chloroformate. Halothane reduced (p<0.05) the intrinsic clearance (Cl~ t) of total propranolol; (CI; t) for the 1-isomer f e l ~ ~ from 11.0+2.7 to 2.6+0.7 ~ i n (p<0.05) while (Cl. ~) of the d - i ~ fell frc~ 4.3+0.8 to 1.5+0.3 L / ~ L , u p<0.05 so that the fall is CI~ t of lpropranolol was greater than the fall in CI'. ~ of d~ 9 1/1 , propranolol. The ratlo of the plasma concentration of 1 to d-propranolol was higher (p<0.05) at each time point during halothane anesthesia. Thus, halothaneinduced inhibition of propranolol metabolism produced a greater reduction in 1 than d-clearance, resulting in proportionally higher concentrations of the mere potent 1-isomer. TABLE: ProDranolol/Clearance (L/rain) Ratio 1 _d total AUC-d/AUC-I Awake ii.0 4.3+ 6.1 2.4 +2.7 -+0.8 -+i.i +0.3 Halothane 2.6* 1.5,+ 1.84, 1.7, +0.7 -+0.3 -+0.4 -+0.i *p
Department of Pharmaceutical Research, Heumann Pharma, Heideloffstr. 18-28, D-8500 Nfirnberg, FRG

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ENANTIOSPECIFIC INVERSION OF ARYLPROPIONIC ACIDS IN VITRO M.P. Knadler and S.D. Hall Inversion of R-arylpropionic acid NSAIDs to the S enantiomer is thought to occur via the sequential action of a CoA thioester synthetase and a postulated racemase. The nature of the enantiospecificity and substrate selectivity of this inversion is poorly defined. The racemate (rac) and enantiomers (0.42 mM) of fenoprofen (Fe), ibuprofen (Ib) and flurbiprofen (FI) were incubated with whole homogenate, eytosol, microsomes, and mitochondria of rat liver in the presence of ATP, CoA, and tritiated water. T h e enantiomers and their thioesters were quantified by a stereoselective hp]c procedure. When S-Fe, S-Ib, S, R, or rac F1 were substrates, thioester formation, tritium incorporation, and inversion of configuration was not detected. For rae, Ib and Fe levels of R enantiomer declined to 82% and 10%, respectively, of initial values. When the R isomers of Ib and Fe were substrates, 35% and 50%, respectively, formed thioesters and net inversion occurred such that the final S:R for non-esterified Fe was unity. S:R for all thioesters formed was unity. When inversion occurred, tritium was distributed equally between R and S enantiomers. For Ib and Fe, thioester formation occurred in mitochondrial and microsomal but not cystolic cell fractions. Following formation of thioesters from the R isomer, racemization occurs in mitochondrial and cytosolic fractions, but in microsomes 30% of the thioesters formed are inverted and racemization goes not occur. These data indicate that CoA thioester synthetase is probably responsible for the substrate selectivity and enantiospecificity noted in the inversion of arylpropionic acids. Furthermore," thioester formation in vitro correlates with the degree of inversion in vivo (Fe>Ib>F1). Division of Clinical Pharmacology, Indiana University School of Medicine, Wishard Memorial Hospital, 1001 West 10th Street, Indianapolis, IN 46202, USA.

STEREOSELECTIVE HYDROXYLATION OF PACHYCARPINE ((+)-SPARTEINE) IN THE RAT T. Ebnera, C.O. Meesea and P. Fischer b (-)-Sparteine (SP) is well-established as substrata for microsomal cytochrome P-450 dbl mediated oxidation, and has been studied inten-sively in the last decade, due to a genetic polymorphism linked with the formation of its major metabolites in man (M.Eichelbaum et al. Xenobiotlca 16" 465 (1986)). In rats, SP is metabolised mainly to 2,3-didehydrosparteine. The percentage formed, however, differs considerably between individual rat strains. We here report on the in v/vo and in v/tro metabolism ot~ pachycarpine (PA), the much less frequently occuring (+)-enantiomer of SP. In marked contrast to SP, PA is metabolised principally to a hydroxy derivative. This has been identified by GC-MS, and, after isolation from rat urine end chromatographic purification, characterieed structurally and stereoohemically by high resolution and two-dimensional 1H and 13C NMR techniques. Oxidation of PA proceeds via stereoselective formation of (+)-(4S)-OH-PA as dominant metabolite (55-60% of the dose administered), with the OH group exclusively in axial position. Other metebolites ere formed in minor quantities. 13 9

~

P

A

1~

14

H

HO

(4S)-OH-PA

The metabolic capacity of different rat strains exhibited the same interstrain differences in PA metabolism as those observed for SP or other drugs affected by the sparteine/debrisoquine polymorphism. SP inhibited in a competitive manner the in vitro metabolism of PA in rat liver microsomes. These data indicate that both enantiomers of this quinolizidine alkaloid are metabolised by the same P-450 isozyme which has a remarkable regio and stereoselectivity for the two enantiomers. Supported by the Robert-Bosch-Foundation, Stuttgart. e) Dr. Margarete Fischer-Bosch-lnstitut for Klinische Pharmakologie, Auerbachstr. 112, D-7000 Stuttgart 50.-b) Institut fQr Orgsnische Chemic der Universit~it Stuttgart, Pfaffenwaldring 55, D-7000 Stuttgart 80

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CUMENE HYDROPEROXIDE-SUPPORTED OXIDATION OF PROPRANOLOL ENANTIOMERS BY HUMAN LIVER MICROSOMES S.V. Otton, M.S. Lennard, G.T. Tucker & H.P. Woods There is evidence that cnmene hydroperoxide (CuOOH) supports preferentially oxidations catalysed in vitro by P450-DB (Zanger et al~ Biochemistry 27, 2447, 1988). Accordingly, the role of P450-DB in the metabolism of propranolol (P) was examined by comparing NADPH- with CuOOH-mediated oxidations. Microsomes from nine human livers were incubated with 40NM (+)P or (-)P in the presence of either CuOOH (125pM, 2min at 20 ~ or an NADPH-generating system (10min at 37~ NADPH supported the formation of 5-hydroxy-P (5HP), 4-hydroxy-P (4HP) and N-desisopropyl-P (NDP) in microsomes from all nine livers. In contrast, NDP was no[ detectable in the presence of CuOOH. Nor did CuOOH support the formation of 5HP and 4HP by microsomes from one liver phenotyped in vitro as a P450-DB 'poor metaboliser j. However, in the remaining eight livers, 5-hydroxylation of (+)P and (-)P varied from 0.010• (mean• n=3) to 0.116• nmol/mg/2min and from 0.016• to 0.245• nmol/mg/2min, respectively. Similarly, 4HP formation varied from 0.021• to 1.87• nmol/mg/2min and from 0.031• to 1.73• nmol/mg/2min. There was a strong correlation between 4HP and 5NP formation from (+)P (r=0.96, p
AN EX VIVO CARBON-13 NMR STUDY ON THE METABOLISM OF S-CARBOXYMETHYL-L-CYSTEINE IN MAN - A REINVESTIGATION C.O. Meese, D. Specht 1, U. Hofmann, P. Fischer 2 and M. Eichelbaum The human metabolism of the mucolytic agent S-carboxymethyI-Lcysteine 1(!) has been reported to proceed via S-oxidation and/or Nacetyiation. In addition, the decarboxylation product S-methyi-Lcysteine ~ and its corresponding metabolites have been detected in human urine after oral administration of 1_ (R.H. Waring, Eur. J. Drug Metab. Pharmacokin. 5:49 (1980)). Because of e large interindividual variability in sulfoxidation capacity which exhibits a bimodal distribution a genetic polymyorphism of this pathway has been suggested (S.C. Mitchell et al., Br. J. Clin. Pharmac. 18:507 (1984)). However, the known analytical methods for the determination of 1 and its metabolites either rely on paper chromatography or require the presence of a free amino group in the analyte. Further more, some of the metabolites Identified are also present as normal food constituents or endogeneous compounds, or are known to be formed by autoxidation during work-up and chromatography. In order to monitor the metabolites which are formed from 1, the stable isotope labelled analogue S-carboxy-[13C]methyI-L-cysteine (13C-1_) was synthesized and administered to humans. Subsequent analysis of native or lyophilized urine samples by carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR) revealed the predominant excretion of two compounds in comparable amounts: unchanged 13C-land 13Cthiodiglycollicl~cid (13C-3_). Simultaneously, small amounts of the sultoxide of C-3. but only traces of the sulfoxides of 1 and essentially no S-methylcysteine metabolites could be detected. These results were confirmed using a newly developed GC/MS assay for the quantitation of endogeneous and metabolically formed 3_. The cumulative urinary excretion of 3, the major metabolite of 1_, during 8h ranged from 8 to 16 % of the dose (1.5 g of 1_) administered (n=lo). On the basis of the present data obtained from the methods described, the existence of a polymorphic sulfoxidation of I is questionable. Supported by the Robert Bosch Foundation, Stuttgart. Dr. Margarste Fischer-Bosch-lnstitut for Klinische Pharmakologie, Auerbachstr. 112, D-7000 Stuttgart 50. -1Abt. Kiln. Chem. RobertBosch-Krankenhaua. -21nstitut f. Org. Chem., Univ. Stuttgart

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RISK ASSESSMENT OF FENOTEROL TREATMENT IN PREGNANCY DESIGN AND EVALUATION STRATEGIES OF A STUDY IN WOMEN WITH PREMATURE LABOUR. R.Hildebrandt,J.MaaBen,H.Kohl,I.Kruck,R.Meister, U.Gundert-Remy,H.Helge and H.Weitzel Premature labour that requires drug treatment occurs to an extent of 10% of pregnancies. In Germany, Fenoterol has been introduced in the treatment since 15 years. However, systematic studies on its safety with regard to the development of fetus and child are lacking. Reports in the literature on the effect on myocardial performance are contradictory. The influence on the regulation of blood glucose level and the psychomotor development has also attracted attention.In an attempt to estimate the possible risks we designed an open study in which women treated with Fenoterol for premature labour were included. The main objectives were myocardial performance measured by systolic time intervals and echocardiogaphy in the neonates, insuline and glucose concentrations in cord blood. Psychomotor development of the children was measured up to 2 years age using Bayley Scales. A nonmedicated controll group could not be introduced for ethical reasons. However, the problem was overcome by stratification of the patient group according to the amount of drug entering the systemic circulation of the mothers as an equivalent to the amount to which the fetuses were exposed. Maternal plasma levels were measured at regular intervals throughout the treatment period. From the data in the literature we calculated a number of 300 patients as an appropriate sample size. Up to now 240 patients were included in the study and 60 children were followed up to the age of 2 years. 65% of elegible patients were included and the drop out rate was 20%. Until now, no major side effects were detected in the children. At the end of the study we will be able to estimate the risk of a treatment of premature labour with Feueterol and to give advise on the rational of therapy. Frauenklinik, Klinikum Steglitz,FU,Hindenburgdamm 30, D-1000 Berlin 45

MATURATION IN ~ - M E T A B O L I ~ IN FAN D.Ullrich; M.Grotefendt; B.M6nch; A.Branden and J.Bircher. Children differ from adults in respect to several aspects of drug metabolism, yet knowledge about development of the corresponding enzyme systems is scarce. Since caffeine (C) undergoes many metabolic transformations we compared urinary C metaboliten in ii apparently healthy children (5 to ii y.) with 7 adolescents (15 to 19 y.) and 15 adults (20 to 68 y.). None of then was smoking or took drugs. They were allowed unrestricted alimontation and xanthine history was recorded. Samples of 24-h urine collections were analyzed by HPLC for C and 14 of its metabolites, using two different chromatographic conditions.Main results: (Medians and ranges) Children Adolescents Adults

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FENOTEROL METABOLISM IN PREGNANT WOMEN U.Gundert-Remy, R.Hildebrandt and B.Wagner The B agonist fenoterol is widely used as a tocolytic 2 agent.The systemic availability of the drug is low, with only I-2% of the dose reaching the systemic circulation on oral administration. In rats, fenoterol glucuronides have been identified as the main metabolitea whereas the metabolic pattern in humans has not been investigated so far. Women treated with the drug in therapeutic doses (5 mg p~o. 4 to 8 times daily or 1.0 to 2.7 ~g/min by continous intravenous infusion) volunteered in an observational study with the aim of establishing concentrationeffects relationships. Blood samples were collected in the course of the treatment. Plasma fenoterol concentrations (F) were determined using a radioimmunoassay after an extraction procedure which separated unchanged fenoterol from its polar metabolites (Rominger, unpublished results). Fenoterol glucuronides (G) and fenoterol sulphates (S) were measured after enzymatic cleavage of the conjugates and determination of unchanged fenoterol. F ranged from 195 pg/ml to 1239 pg/ml and from 665 pg/ml to 2214 pg/ml in oral and intravenous treatment, respectively. S and G were detected in the plasma from both patient groups. The ratio between G and F was 12.8 + 4.9 (n=lO) and 1.6 + 0.3 (n=4) and the one between and F was 105.5 ~ 4~.4 and 3.5 ~ 1.9 in the orally and intravenously treated patients, respectively. The ratio between G and S was 0.13 + 0.06 and 0.64 + 0.37 in the orally and intravenousTy treated patients, respectively. From our results we conclude that the low systemic availability of fenotprol can be explained by extensive presystemic elimination. With both routes of administration, the metabolite pattern is qualitatively the same. However, their quantitative distribution is different. This finding suggests that gut wall metabolism plays an important role in the presystemic elimination of fenoterol. Institut for Arzneimittel, Seestr. i0, D-IO00 Berlin 65

Total output of Cderivatives (mg124h)

86* (87-693)

309 (163-583)

501, (223-i061)

CAFFEINE D~THYLATION~ ) (%): Paraxanthine formation 47(19-83) Theophylline formation 18(5-30) Theobrc~ine formation 38(6-58)

62(30-75) 12(7-26} 22(16-40)

60(27-83) 13(5-24) 19(9-47)

i - ~ OXIDATIOn, (%): l-methyluric acid formation 99(93-100)* 94(91-100)

86(71-100)*

~c~-n~oN reACTIONS: (%): 13-dimetbyluric acid 0(0-0.2)* 0(0-0.5) 17-dimethyluric acid 0.2(0-1.2)* i(0-1.8)

0.9(0-8.5)* 4(0-7)*

*significant difference p<0.001;1)sum of respective dimethyl-manthine and derived meta~olites in percent of total C-metabolites;2)in percent of total l-methylxanthine. Conclusions: Since the above findings were not dose dependent, the study demonstrates quantitative age related changes. Assessment of C-metabolism appears well suited to study maturation of several pathways relevant for the metaholien of xenobioties in pediatric patients. Department of Clinical Pharmacology; University of G6ttingen;FRG.

XENOBIOTIC EXPOSURE vIA BREAST MILK: A COMPUTER MODEL P.J. McNamara and R.Teng Today greater than half of all newborn infants are breastfed and thereby exposed to a variety of drugs and environmental contaminants via breast milk. To determine the safety for the neonate, it is essential to be able to predict the amount of drug presented to the neonate (dose). Studies in humans and rabbits suggest that most drug milk to plasma ratios (M/P), hence neonatal dose, can be predicted from simple laboratory experiments using a diffusion model. However, it is critical that risk assessment focus on drug concentration at the site of action in the neonate following acute/chronic exposure. Literature evidence suggests that estimating infant risk using M/P values to calculate and express neonatal exposure relative to the maternal daily dose may be misleading. For example, caffeine would appear to present limited exposure to the infant expressed in terms of maternal dose, whereas plasma concentrations may approximate those of the mother and constitute a greater concern. A pharmacokinetic model was developed which incorporates drug transfer between maternal plasma and milk via a diffusional clearance of unbound, unionized drug, and the physiological constraint that 75% of the milk compartment is regularly turned over due to nursing. Model simulations will be presented to illustrate several key issues: first, M/P values do not directly relate to infant exposure. Secondly, the ultimate effects of neonatal exposure via milk can only be recognized following multiple dose exposure since neonatal plasma levels may accumulatevery slowly. Thirdly, it appears unlikely that milk will act as a 'deep' compartment due to the substantial turnover of this compartment. A realistic assessment of infant exposure/risk to a particular xenobiotic via breast milk must take into consideration not only the infant dose, but the pharmacokinetics in the neonate, as well as, the pharmacological sensitivity and immature physiology of the neonate. College of Pharmacy, University of Kentucky, Lexington KY, U.S.A,, 40536. (Supported in part by ROI GM38836-OIAI)

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SULPIRIDE EXCRETIONIN LACTATING MOTHERS *T. A. Moreland,+M. L. Donnet,*j. McEwenand+P. W. Howie

CEFMENOXIME PHARMACOKINETICS AND RENAL FUNCTION IN N E W B O R N I N F A N T S A. Higashi, C. N a k a m u r a , T. Ikeda, K. Iribe, N. I n o t s u m e , M. N a k a n o a n d I. M a t s u d a

The dopamine receptor antagonist sulpiride can augment lactation at conventional doses (50 mg bd). Work in Dundee (McMurdo et al, Brit J clin Pharmacol 24, 133, 1987) has shown that very low doses of sulpir]-de (1 mg) retain potency in respect of prolactin release, so may retain the a b i l i t y to augment lactation. We have examined the excretion in milk of single oral doses of either 3 mg (n = 5) or I0 mg (n = 4) of sulpiride in lactating mothers who were expressing milk postpartum. Sulpiride levels were assayed by HPLC-fluorescence. The results (see Table) show significant excretion of sulpiride in human milk. In three patients (I, 2, 8) the plasma profile of sulpiride was also studied: maximum levels were 2 to 6 fold lower than in milk and sulpiride was v i r t u a l l y undefectable in plasma at 24h. patient 1 2 dose (mg) 3 10 mcg in milk 8.3 18.5 over 24h max milk 37 78 conc (ng/ml)' milk conc 13 29 at 24h

3 4 3 10 2.8 46.3

S 3 3.5

6 10 5.6

7 3 1.2

8 10 3.8

9 3 9.9

23

293

23

61

10

37

28

12

84

13

35

13

32

9

Although the amount in milk appears small as a percentage of the dose, even with low dose s u l p i r i d e treatmenf a baby could receive the adult equivalent of about I mg per day, which we have p r e v i o u s l y shown to cause significant e l e v a t i o n of plasma p r o l a c f i n .

The p h a r m a c o k i n e t i c d i s p o s i t i o n of c e f m e n o x i m e (CMX), w h i c h is a n e w t h i r d g e n e r a t i o n cephalosporin add active against most gramp o s i t i v e a n d - n e g a t i v e agents, was s t u d i e d in n e w b o r n infants, s i n c e r e l e v a n t d a t a w e r e lacking. C M X is m a i n l y e l i m i n a t e d t h r o u g h the k i d n e y and, thus, d e v e l o p m e n t of r e n a l f u n c t i o n in r e l a t i o n to d r u g m e t a b o l i s m was t a k e n i n t o a c c o u n t in the study. C M X c o n c e n t r a t i o n s in s e r u m a n d u r i n e w e r e m e a s u r e d by HPLC. The d r u g (17-49 mg/kg) was g i v e n i n t r a v e n o u s l y to 7 n e w b o r n i n f a n t s (4 p r e m a t u r e a n d 3 m a t u r e ) a n d 4 o l d e r i n f a n t s (3 to 13 m o n t h s ) . T h e m e a n TI/2 value was 6.2• (mean• h in n e w b o r n i n f a n t s and 0.8• h in o l d e r i n f a n t s (p<0.001). The a p p a r e n t v o l u m e of d i s t r i b u t i o n w a s S i m i l a r in the d i f f e r e n t age g r o u p s . The t o t a l c l e a r a n c e of C M X was p o s i t i v e l y c o r r e l a t e d w i t h c r e a t i n i n e c l e a r a n c e (y:0.98) as w e l l as the r a t e of t u b u l a r r e a b s o r p t i o n of ~2 m i c r o g l o b u l i n (BMG) (y=0.83), a n d n e g a t i v e l y w i t h the u r i n a r y B M G concentration (u The r a t i o of r e n a l C M X c l e a r a n c e to c r e a t i n i n e c l e a r a n c e was l o w e r in newborn infants than older infants, indicating t h a t t u b u l a r e x c r e t i o n of C M X w a s d e v e l o p e d a f t e r the n e w b o r n p e r i o d . The urinary BMG c o n c e n t r a t i o n m i g h t be a u s e f u l i n d i c a t o r for p r e d i c t i n g t o t a l C M X c l e a r a n c e in i n f a n i s .

*Drug Development (Scotland) Ltd and+Dept of Obstetrics and Gynaecology, Ninewells Hospital and Medical School, Dundee, DDI 9SY, Scotland.

D e p a r t m e n t of P e d i a t r i c s , K u m a m o t o U n i v e r s i t y M e d i c a l School, K u m a m o t o 860, J a p a n

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TNZRJIo FGNCTION, PHYSICAL AND MENTAL DEVELOPME~I' I[q INFANTS WHO RECEIVED CARBIMAZOLE DURING FETAL LIFE AN[; LACTATION

PHARMACOKINETICS AND SAFETY OF PROCHLORPERAZINE IN PEDIATRIC PATIENTS RECEIVING CANCER CHEMOTHERAPY M.C. Nahata, C. Ford, J. Koepke, F. Ruymann and Nell Grossman Nausea and vomiting are common clinical problems in patients receiving cancer therapy. Metoelopramide is often used but it frequently causes extrapyramidal reactions. In search for an alternative, proehlorperazine is prescribed but no pharmacokinetics data are available in pediatric patients to guide the dosage requirements. The primary objectives of this study were to evaluate the pharmacokinetics and safety of intravenous prochlorperazine in pediatric patients receiving cancer chemotherapy. Eleven patients (ages one to nine years) receiving high doses of cisplatin or cyclophosphamide were-given three or four intermittent doses of prochlorperazine, 0.2 mg/kg intravenously over six to nine hours. Multiple bl~ed samples were collected and prochlerperazine was quantitared by a specific gas liquid chromatographic method. Peak serum concentrations ranged from 402 to 5,608 ng/ml. Total clearance, apparent distribution volume and elimination half-life ranged from 0.03 to 0.28 (mean: 0.12) L/kg/hour, 0.24 to 1.2 (mean: 0250) L/kg and 1.2 to 15.5 (mean: 5.6) hours, respectively. No adverse effects were observed in our patients. Three patients had uncontrolled episodes of vomiting during prochlorperazine therapy. The serum concentrations of proehlorperazine in these patients were low, and ranged from 402 to 1202 ng/ml. These data suggest: (i) there was a substantial interpatient variability in prochlorperazine pharmaeokinetics so the dose requirement may differ among patients; and(2) prochlorperazine appeared safe at the doses used but higher doses may be required to control nausea and vomiting in pediatric patients receiving high-dose cisplatin or cyclophosphamide therapy. Colleges of Pharmacy and Medicine, The Ohio State University and Children's Hospital, Columbus, Ohio and Florida A&M University College of Pharmacy, Tallahassee, Florida

PN Bennett, ARR Cain, GD Dunster, 53 Humphries, BA Marriott,S Murray, LJ Notarianni, JP Osborne, JPD Reckless, ~s Rudd. Suppression of thyroid function may be necessary during pregnancy and lactation but the effects of such dru 9 treatment on infants needs to be assessed. Fifteen mothers received carbimazole 10-20 mg/d for 12-40 weeks during pregnancy and 9 continued to take the drug during 2-26 weeks of lactation. Their infants were monitored for up to 18 months. Infant thyroid function was within nornml over this period, the range of mean values for individuals being TSH 1.4-5.9 mu/l, free T3 6.2-9.3 pmol/l and T4 104-189 nmol/l. Steady state concentrations of carbimazole (assayed as methimazole by h.p.l.c) in milk from 5 mothers were 6-51 ug/l and the milk to plasma ratio was 0.49-0.61. The estimated quantity of carbimazole ingested by the infants in milk was 0.5-3.2% of the weight-adjusted maternal daily dose. Ten mothers who received no carbimazole either during pregnancy or lactation and who were studied concurrently also exhibited normal thyroid function, with TSH 2.0-5.6 mu/l, free T3 6.6-9.0 pmol/l and T4 i16-176 nmol/l. Physical examination at intervals for 2-18 months was normal in all infants who received carbimazole and Griff~ths mental development scales (i) were normal in all 6 infants who were assessed at 18 months. The data suggest that exposure to carbimazole during fetal life and lactation does not impair infant thyroid function, physical or mental development. (i) Griffiths R (1954) The abilities of babies. University of London Press. School of Postgraduate Medicine, BA2 7AY, United Kingdom.

University of Bath, Bath

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INFLUENCE OF DIFFERENT ANTIEPILEPTIC THERAPEUTIC MODALITIES ON PLASMA FOLATE CONCENTRATIONS IN CHILDREN. C.M.Eodriguez-Lopez, E.P.Calandre, E.RodriguezSanchez. It is usually assumed that anticonvulsants decrease serum levels of relic acid and can, eventually, originate megaloblastic anemia; this effect has been demonstrated for phenytoin, phenobarbital and primidone, but data about other antiepileptic drugs are rather scanty. We measured f01ic acid and vitamin BI2 plasma concentrations in 113 epileptic children (age range:2-18 years; mean:9.02~3.8) and in 32 matched controls. Epileptic subjects received chronic treatment with valproic acid (n=54), earbamazeplne (n=21), phenobarbital (n=ll) or politherapy (n=27). Folate plasma levels were significantly lower in each group of treated children than in controls (mean values:5.62+2.3 for valproate, 5.21+2.3 for earbamazepine,-4.2Ozl.l for phenobarbital, 4.40~2.5 for politherapy, and 7.08+2.1 in healthy subjects; F=6.632, P < 0.00017. Vitamin BI2 concentrations were similar in controls and in epileptic patients. Folate l e v e l s ~ 5 ng/ml were found in 29 (87.5%) controls, in 44 (63.8%) children receiving valproate~ i0 (47.6%) children receiving carbamazepine, 9 (33.3%) children receiving politherapy, and only 1 (9.1%) child receiving phenobarbital (X2: 84.45, P ~ 0.0001). It is concluded that although every one of the investigated therapies exerts an antifolate activity, this side-effect is substantially lower when using valproic acid or carbamazepine than phenobarbital or politherapy. Departamento de Farmacologia. Facultad de Medicina. 18012 Granada. Spain.

IBUPROFEN LIQUID: MULTIDOSE TREATMENT OF FEBRILE CHILDREN P.D.Walson, G. Galletta, F. Chomilo, P. Graves, L. Alexander and M. L. Scheinbaum The antipyretic efficacy of ibuprofen has been demonstrated in children, but most studies have compared single ibuprofen doses to relatively low doses (I0 mg/kg) of acetaminophen. A double-blind, multiple-dose (q 6 hr for 1 to 2 days), parallel-group study was done to compare the efficacy of three doses of ibuprofen liquid (2.5, 5.0, and I0 mg/kg) with acetaminophen elixir (Tylenol ~, 15 mg/kg) in the treatment of pyrexia in children (n=64) aged 6 me through ii yrs. In 61/64 evaluable patients, the rates of temperature reduction and maximal reduction of fever were equal for ibuprofen 10 mg/kg and acetaminophen 15 mg/kg and both were more effective than smaller doses of ibuprofen. Six children were withdrawn from the study; 2 for dosing errors, 3/16 acetaminophen patients for hypothermia (temp < 96~ and gastrointestinal distress in 1/16 ibuprofen (2.5 mg/kgl treated children. No other significant symptoms or adverse laboratory or physical findings were noted. Ibuprofen liquid (2.5 to i0.0 mg/kg/dose given every 6 hours for 24-48 hours) appears to be a safe and effective antipyretic in febrile children. Clinical Pharmacology/Toxicology, Dept of Pediatrics, Children's Hospital, The Ohio State University, Columbus, Ohio, 43205.

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EFFECTS OF INCREASINGDOSESOF VIGABATRIN~SEIZURES AND PLATELETGABA-T ACTIVITY IN CHILDRENWITH REFRACTORYPARTIAL EPILEPSY. Armijo J.A., *Arteaga R. and *Herranz J.L. Clinical Pharmacology and *Neuropediatrie Divisions, Hospital "M. de Val decilla", University of Cantabria School of Medicine, Santander. Spain.

PHARMACOKINETICS OF KETOROLAC IN CHILDREN E.-L. Maunuksela and K, T. OIkkola Ketorolac 0.5 mg/kg was given intravenously to eight small healthy children (age 4-6 yr, weight 18.5-23.3 kg) after minor surgery, Plasma concentrations were measured until the next morning. The individual plasma concentrations (Fig. 1) were fitted to a biexponential equation interpreted as a two-compartment open model using weighted nonlinear least-squares regression. Volumes of distribution (Vda) , clearances (C1) and elimination half-lives were calculated according to standard formulae.

Effects of Vigabatrin (GVGi on number of seizures and platelet GABAaminotransferase (GABA-T) a c t i v i t y were studied, as add-on therapy, in 17 pediatric outpatients (12 g i r l s ) , aged from 5 to 20 (15.5~3.5, M+_SD), with drug resistant partial epilepsy treated with 1.6 (I or 2) antiepileptic drugs: benzodiazepines (9), valproate (8), carbamazepine (6), phe nytoin (2), phenobarbitone ( I ) and primidone ( I ) . After 2 months baseline and I month single-blind placebo periods, a fixed dose of GVG was given for 2 months ( I , 1.5 or 2 g/day for children between 12-16, 17-22 and 22 kg, respectively). In 13 patients whose seizures were not suppre~ sod, GVG doses were increased to 1.5, 2 and 3 g/day respectively for at least 2 months more. Efficacy, toxicity, antiepileptic plasma conceotrations and platelet GABA-T a c t i v i t y were monthly evaluated. With the low dose of GVG (56~16 mg/kg/day) a reduction in the number of seizures of 68+29% was observed (I00%, 75-100%, 50~75% and 0-50% in 4, 4, 5 and 4 patients, respectively). The number of seizures/month lowed from 44+59 to 20+50 (paired "t"=2.9, p <0,01). Platelet GABA-T ac tivity decreased from 13.2 +7,8 to 4.7§ pMol/min/mg protein. Threre was a significan t correlation between GVG doses and seizure reduction percentages (r:0.51, p < 0.05) but not either between GVG doses and GABA-T inhibition (r=O.07) or between seizure reduction and GABA-T inhibition (r=0.22). Side effects were observed in only one patient (con~ tipation), Influence of GVG on plasma concentration of other antiepilep tic drugs was not detected.

In the 13 patients whose GV$ doses were increased, not a significant reduction in the number of seizures was found (54~76, 26~55 and 28+55 seizures/month for non-GVG, GVG low doses and GVG high doses periods, respectively). Furthermore, not a greater inhibition of platelet GABA-T activity was seen (14.8~8.3, 4.7~2.5 and 4.8~2.8 pMol/min/mg protein, respectively). Short-term vigabatrin add-on treatment has been effective and well tolerated in children with refractory partial epilepsy, but we have not found a clear relationship between efficacy and GVG doses or platelet GABA-T inhibition.

Figure 1 Semilogarithmic plot of plasma ketorolac concentrations after intravenous ketorolac

Plasma llJ `

ketorolac

(rag/I)


istration to eight children.

0,011 0

. 200

. . . l 400 600 800 1000 1200 1400 Time (min)

M e a n (_+ SO) e l i m i n a t i o n half-life was 342 _+ 112 rnin, Vd# 0,56

+- 0.35 1/kg and CI 1.11 _+ 0.34 ml/min/kg. Ketorolac clearance and volume of distribution were about two times higher than in adults. Accordingly, the mean elimination half-life was at the same level as in adults. The higher clearance in small children is in good agreement with previous studies on the pharmacokinetics of various drugs in different age groups. Correspondingly, since ketorolac is a water soluble drug, its larger volume of distribution is in agreement with the larger extracellular fluid volume of this age group. Department of Ophthalmology, Helsinld University Central Hospital, Haartmaninkatu 4, SF-00290 Helsinki, Finland

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P A R E N T D R U G P R E S C R I P T I O N IN C H I L D R E N J. Boada, J. D u q u e and E. S a n z The s t u d y w a s p e r f o r m e d in the " H o s p i t a l de N i ~ o s " of T e n e r i f e (The C a n a r y I s l a n d s ~ Spain). A questionnaire, i n c l u d i n g social, m e d i c a l and pharmacological s u b j e c t s , w a s f i l l e d in by p e d i a t r i c i a n s in c h a r g e of o u t - p a t i e n t c o n s u l t ing. Data f r o m i005 r a n d o m l y s e l e c t e d p a t i e n t s , a g e d u n d e r ~4 years, w e r e c o l l e c t e d . M o s t of the c h i l d r e n (73%) w e r e a l r e a d y u n d e r t r e a t m e n t at the m o m e n t of the c o n s u l t a t i o n ~ the p a r e n t s b e i n g r e s p o n s i b l e for p r e s c r i p t i o n in 6 9 % of the cases. 2/3 of them r e c e i v e d o n l y o n e drug, w h e r e a s t h o s e t r e a t e d by p h y s i c i a n s r e c e i v e d a s i n g l e d r u g in o n l y i/3 of the c a s e s A n a l g e s i c s (55%) and a n t i b i o t i c s (9%) w e r e t h e d r u g s m o r e c o m m o n l y p r e s c r i b e d by the p a r e n t s ; p h y s i c i a n s u s e d a n t i b i o t i c s in 24% of p a t i e n t s and a n a l g e s i c s in ~3%. T h e i n f o r m a t i o n s o u r c e s h a b i t u a l l y h a n d l e d by parents were previous physician prescriptions and p a c k a g e i n s e r c s (PI). T h e y c o n s u l t e d the d o c t o r en ~/5 of the cases, and o n l y s e l d o m they a s k e d a p h a r m a c i s t or a n o t h e r person. W h e n a d i s c r e p a n c y b e t w e e n the d o s e p r e s c r i b e d by the d o c t o r and that d e s c r i b e d in the PI w a s d e t e c t e d , n e a r l y 70% of the p a r e n t % f o l l o w e d the p h y s i c i a n ' s r e c o m m e n d a t i o n s , but 20% of t h e m f o l l o w e d the PI i n f o r m a t i o n or their own c r i t e r i a . 9 1 . 3 % of the p a r e n t s c l a i m e d to u n d e r stand the PI, w h i c h w a s in d i s a g r e e m e n t w i t h the m u l t i p l e m i s t a k e s n o t i c e d in the p ~ e s c r i p tions. T h e s e d a t a r e i n f o r c e the r e l e v a n t r o l e p l a y e d by the p h a c m a c o l o g i c a l a n a m n e s i s in the general medical practice. Dept. F a r m a c o l o g { a . U n i v e r s i d a d de La L a g u n a . P.O. Box 55~ La C u e s t a . 38080 S a n t a C r u z de T e n e r i f e . Espa~a.

BETWEE~AND WITHIN-SUBJECT VARIABILITY IN PSYCHOMETRIC TEST SCORES B. F. Johnson, K. Hoch and J. Johnson A major problem in studying drug effects upon psychometric functions is that subjects show spontaneous improvement with repeated testing. It has therefore been recommended that subjects be trained before entering multiple test experiments to study drug effects after the effect of practice has stabilized. This practice effect was determined in six types of tests given on eight occasions over 12 weeks to 13 (six male, seven female) healthy volunteers, aged 20-60. All abstained from caffeine, smoking and alcohol, and none tookdrugs of any kind. No plateau in the practice effect occurred. Stepwise mean (ZSD) decrease in Choice Reaction Time (0.53• to 0.44• see), Short Term Memory Errors (91• to 36• and Card Sorting Time (62• to 55• sec) and stepwise mean increase in scores for Mathematical (40.5• to 53.7• Visual Vigiiance (123• to 152• and Digit-Symbol Substitution (319• to 407• skills developed progressively over the sequence of tests. An alternative approach to training is to perform parallel design studies. However, between-subject variation was also large both for baseline scores and in the slope of practice improvement~ so that variability between randomized groups could be large. Pre-trial training is usually impractical for clinical trials. Variability in the practice effect makes it essential to define individual learning rates by pre- and post-intervention placebo runs. Division of Clinical Pharmacology, University of Massachusetts Medical Center, Woroester~ Massachusetts 01655 USA

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ASPIRIN PLASMA MONITORING IN JUVENILE CHRONIC ARTHRITIS AND ITS EFFECTS ON LIVER FUNCTION TESTS S.D.Seth, B.Sharma, V.geth, N.Basu and A.Beotra. Thirty two patients suffering from juvenile chronic arthritis (,]CA) in the age group of 5-15 years were taken from the Pediatric Rheumatology Clinic of the A.I.I.M.S., New Delhi for saJicylate monitoring. Of these, 15 (46.9%) had polyarthritis, 11 (54.4%) suffered from systemic onset type of JCA and only 6 (18.7%) had pauciarticular type of arthritis. The salicylates (free, bound and total) and albumin levels on 1,7,14 and 21 days were estimated after therapy in 52 patients of .]CA. The fluorimetric method was used for estimating salicylates. Serum SGOT and 5GPT were monitored besides clinical evidence of hepatotoxicity. The therapeutic levels of saticy]ates in the range of 1S to 25mg/dl were achieved by the dosi~ge in the range of 70-110mg/kg/day or 1.9 to 2.8gm/M~/day. Steady state was achieved by seventh day and the level was 2.8 times higher than the Ist day. Binding was found to be dependent on the dosage of salicy~ates and a]bumJn levei. It was not saturated in the dosage range given. The increase in transaminase levels was only one-and-half to twice the normal ~evet. None of the children developed clinical evidence of hepatntoxicity. The studies indicate that dosage of salicylate can be given either oq body weight or surface area basis in children. A malnourished child with lower levels of serum albumin may be more predisposed to salicylate toxicity, due to higher levels of free salicylates. There was no evidence of hepatotoxicity in the dosage range of 70-110mg/kg/day or 1.9 to Departments of Pharmacology and Pediatrics. All India Institute of Medical Sciences, New Delhi, India.

STANOARDIZATION OF A COMPUTERSUPPORTEDPtYCHOEXPERIMENTAL TEST-BATTERY COVERINGTHE PSYCHOLOGICALFUNCTIONSPSYCHOMOTOR PERFORMANCE, COGNITION,V[SU-~OTOR COORDINATION,AND MOOP~ OBJECTIVITY, RELIABILITY,AND VALIDITY H. Oft, O. ,$eitz r B.Vost, R, B~eel 35 male volonteers participated in a drug-free nethodo~oglca] study. The psychoexper~menta} testrbattery (constructed by G, Sch~ler and W. Reske) consisted of the foHowing tests; Tapping, pegboard, visual reaction tlne (MRT), delayed retention '(MRT/G),' video-trackiog, Paeli-perfsrnance-test, and visual analogue scales, The computer supported test-battery was adninistered on 3 subsequent study days with 3 measurements separated by a time interval of 2 hoers between each test ru~, and a 4th study day after 7 days with the same measurement points in the mor~ing, noon and afternoon. The learning curves of the individual subject as wel} as of the tote| group were established, At the end of the learning plateau on study ~ay S to 4 toe r e l i a b i l i t y cdefficients ranged between .~5 (MRT/G) und .92 (Tapping), Accordlng to the high r e l i a b i l i t y coefficients the duraRion of some of ~he tests COuld be reduced.Fao~or analysis with VARI~AXrotation revealed fear indegende~ factors which were claesifled as mood ("8efind]ichkeit"), cognition, motor-performance and visu-~e%er coordination. The Raven-Co]oaredProgressive Matrices, a non-verbal intelligence measure, was to some extend related to the measures of cognitlons. garlier humanpharmaeologica] studies with compounds from different drug classes including benzodiazepines and neuro]eptIce have demonstrated the "pharmaco sensitlvity" of the psyeheexperimental measures. The computerized psy~hoexperimental test-battery wl]1 meet the criteria of the classical test theory and the requirements of standard operation procedures (SOP) of the intarnatlonal GCPguidelines. Scherlng AG. Main Dept, Bumanpnarmacology, Oegt. PharmacopsychoJegy, Postfach 66 03 11, D-tOO0 Berlin 65

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COMPARISON OF V~$UAL AND AUTOMATIC ANALYS~$ OF NIGHT-SLEEP EEG L. H~ller, St. K u b i ~ I. Beta. R. Dorow Oxford Medical has introduced an automatic sleep stager ~ased on the stage scorin~ criteria by REcHTSCHAFFEN and KALES. The aim of this investigauion was to examine the reliability o~ this automatic stage-scoring system (Oxford sleep staser, version 3.0), and to compare the results with those of two independent visual raters, Ten a!l-ni~ht sleep recordings of subjects without sleep disturbances Served as a basis for the comparison. Each sleep-recording was scored twice automatically by the stager, ~wlce visually hy the first rater and once by the second rater. The two autommtic analTse ~ of the sleep recordings differed by 4.3 Z in a total of 13,850 epochs (1 epoch e 20 sac) regardin~ sleep stage scoring. The difference between the first and the second visual evaluation by the same rater amounted to 5,? Z, whereas the results of the two independent ra~ers deviated by ~.7 ~. Compared to the results of the visual analysis reached as a consensus by both raters the so-called optimized visual analysis - the stager showed a 26.9 Z difference. The automatic analysis scored less epochs as stages wake, REM, and 2 and more as stage i, 3 and 4. The sleep stager's frequen~ difficulty in identifying stage wake correctly as well as its inCorreCt allocation to other stages - mainly stage RE}4 - could lead ~o misinterpretations of sleep recordings, whereas the increase in stages i, 3 and 4, as compared with visual scoring, is negligibla. Schering A@, .Main Dept. HumanpharmacOlCgy, Dept. Pharmacopsychology, Postfach 65 05 ii, D-1000 Berlin 66

EFFECTS OF THE DoPAMIN KECEPTOK ANTAGONISTS HALOPERIDOL AND BROMERGURIDE ON MOOD, PSYCHOMOTOR pERFOKMANCE, FKAILMAG0-EE@, AND PROKAOTIN SECRETION IN HEALTHY VOLU~TEEK$ A:Kohlo~f, H. Oft 45 male volunteers received either 4 mg Haleperidol, or 4 mg Bromerguride (an ergolina derivative under research), or placebo in a single oral dose aocordin~ to a randomized double-blind parallel group design (n - IS per group). The aim of the hUman pharmacological study was to identify the "neuroleptie profile' of Bromerguride in comparison to Haloperidol. Both drug treatments reduoad the performance in gross motor 5ehaviour, visumotor coordination and impaired well-being and mood compared to placebo. The pharmacoEEG-prcfile was characterized by an increase of the portions in the delta-, theta-, and beta-frequencles and by a decrease of the alpha portions. Both druss showed the typical dopamin-blockade by the increase of prolactin levels and the production of the wellknown spectrum of "neuro!eptic side effects". The main difference between Bromerguride and Haleperidol disclosed as well on the behavioral level as on the level of hypophysis was the time laE between the two time-effect-curves; Bromer~uride 4 mg induced earlier and s~ronger the above mentioned behavioural impairments and visilance reductions than Haloperidol 4 m~; under Bromerguride 4 mg the pro!actin secretion peaked e~rlier and less higher than under Mslcperidol 4 mg. In conclusion, Bro~erguride 4 m~ revealed the typical '~neuroleptic profile" as known% by Haloperidol but the effects culminated earlier and lasted shorter than under Halcperidol 4 mg. Sobering A~, Main Dept. Humanpharmaeology, Dept. Pharmacopsyehology, Postfach 65 05 Ii, D-1000 Berlin 65

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PSYCHOTROPIC DRUGS DIFFERENTLY INFLUENCE THE HIGH-AFFINITY BINDING OF 3H-IMIPRAMINE IN HUMAN PLATELET MEMBRANES D. Marazziti, A. Rotondo, M.F. Falcone, G.B. Cassano The effects of various psychotropic drugs, desipramine (D), amitriptyline (A), chlorpromazine (C), haloperidol (H), phenytoin (PH), pentobarbital (P), phenobarbital (PHE), morphine (M), orphenadrine (O), carbamazepine (CA), verapamil (V), nifedipine (N), phenelzine (PZ), and lithium carbonate (L), were studied on the binding of 3H-imipramine (3H-IMI) in human platelet membranes. The binding was studied with 2nM 3H-IMI. Of the drugs tested, the tricyclics D and A exerted the strongest inhibitory effect that was concentration-dependent. Significant inhibition was obtained with C, H, V and N, while the remaining drugs had no significant effect on the binding of IMI. Dose-response curves of the active drugs indicated that nanomolar concentrations were enough to exert displacement of IMI. These results do indicate that different psychotropic drugs, with different molecular structures, interact with the same target, i.e., the binding of IMI to platelet membranes. Department of Psychiatry and Department of General Pathology, Medical School, University of Pisa, via Roma, 67, 1-56100 pisa, Italy

BENPERIDOL SERUM CONCENTRATIONS AND CLINICAL EFFECT IN ACUTE SCHIZOPHRENIA M. Furlanut, G. Colombo, P. Benetello, G. Zara, M.Baraldo. Nineteen acute schizophrenic patients, untreated with other neuroleptics for at least a month, were administered benperidol (B) in monotherapy. Twelve were males, 7 females. The age ranged from 17 to 72 years. Mean (_+SD) b.w. and mean (+SD) B oral dose (mg) were 63.42+9.54 and 4.63+1.68, respectively. Antipsychotic effect was evaluated by means of BPRS; extrapyramidal symptoms by EPS. B-serum concentrations were determined according to an HPLC procedure coupled with eletrochemical detection. After a week of treatment, 7 patients experienced >50% improvement, 1 worsend, 1 did not respond, and l0 scarcely responded (28.25+17.57% improvement). BPRS and EPS correlated positively with B serum concentrations (y=30.444+l.39x, r=0.32; y=18.052+1.81x, r=0.47). Mean (+SD) serum concentrations (ng/ml) in improved patients were sTgnificantly higher (7.47--+5.33) than in uniproved ones (3.33+--2.59). The difference was statistically significant (p=0.03). Departement of Pharmacology, Institute of Psychiatry, Institute of Neurology, University of Padua, Italy.

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INFLUENCE OF MILACEMIDEAND TRANYLCYPROMIHEON TYRAMINE PRESSOR RESPONSEIN HEALTHYVOLUNTEERS *C. J. Durnin, *J. McEwen, +J. E. Kirby and +P. S. Kiff

* * * p
DANISH UNIVERSITY ANTIDEPRESSANT GROUP (DUAG) - A PERVANENT INDEPENDENT MULTICENTER GROUP FOR I~PROVED C~ALITY IN CLINICAL TESTING OF NEWANTIDEPRESSANTS L.F. Gram, P. Kragh-S~rensen P. Beeh, N. Reisby, P. Vestergaard and T.G. Bolwig Concerns about the q u a l i t y o f c o n t r o l l e d t r i a l s w i t h new a n t i d e p r e s s a n t s and the p o t e n t i a l r i s k o f marketing of less e f f e c t i v e a n t i d e p r e s s a n t s led to the formation o f DUAG. This permanent m u l t i c e n t e r group encompasses the t h r e e u n i v e r s i t y p s y c h i a t r y departments, some o t h e r leadin9 p s y c h i a t r y departments and a c l i n i c a l pharmaco1o9y department in Denmark. Through t r i a l s w i t h new antidepressant~ the group aims at improvin 9 standards and methodology o f such s t u d i e s . Two s t u d i e s on two s e l e c t i v e s e r o t o n i n reuptake i n h i b i t o r s have been concluded, and a t h i r d study on a r e v e r s i b I e M A O - i n h i b i t e r viii be concluded in 1990. In a l l three s t u d i e s c l o m i pramine served as r e f e r e n c e treatment. The f i r s t two studies showed the s e l e c t i v e s e r o t o n i n reuptake i n h i b i tons ( c i t a i o p r a m , p a r o x e t i n e ) to be c t e a r i y less e f f e c t i v e than clomipramine. A f t e r 4 weeks treatment, the percentage of p a t i e n t s c l a s s i f i e d as non-responders ( r a t i n g scale) were: Study I : c i t a l o p r a r n : 45 (n=5O) c]omipr~Tline: 13 (n=52) Study I I : p a r o x e t i n e : 34 (n=56) clomipramine: 13 (n=46) Likewise, the 9roup average Hamilton r a t i n 9 score was 14-15 f o r c i t a l o p r a m and p a r o x e t i n e and 9-10 f o r the two clomiprernine m a t e r i a l s . These resuJts are in sharp contrast to a v a i l a b l e t r i a l data on s e t e c t i v e s e r o t o n i n reuptake i n h l b i t o r s , u s u a l l y concluding "no d i f f e r e n c e " against t r i c y c l i c a n t i d e p r e s s a n t s . The inclusion of only in-patients, strict c o n t r o l o f drug i n t a k e and r i g l d adherence to a f i x e d , e f f e c t i v e dose schedule in the DLt~G-studies are methodological f a c t o r s that may e x p l a i n the d i s c r e p a n c i e s . Independent, permanent t r i a l groups o f t h i s kind are ne6~ded to ensure the q u a l i t y o f the c l i n i c a l t e s t i n g o f a n t i d e p r e s s a n t s in the f u t u r e . Department o f C l i n i c a l Phar!r~cology , C~dense U n i v e r s i t y , J.B. Winslews Vej 19, DK-5000 Odense C.

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Milacemide is a glycine prodrug and an inhibitor of MAO-B; its therapeutic properties as a novel neuropsychotropic agent are being investigated. In order to assess the effects of chronic administration of milacemide on the pressor reponse to tyramine, 12 healthy volunteers (6M, 6F) completed a double-blind parallel group study, with tranylcypromine as positive control. Subjects assigned to milacemide received 1200 mg tds for 21 days, with placebo tranylcypromine during Days 19-21; subjects assigned to tranylcypromine received placebo milacemide for 21 days, with tranylcypromine 10 mg bd during Days 19-21. During the study alcohol intake was restricted and a tyramine-free diet was taken. A standard tramine pressor test (Ghose et al, Lancet 1975 i, 1317) was performed on Days O, 18 and 21: the dose of tyramine required to raise the systolic arterial pressure by 30 mm Hg (T30) was calculated. The results are shown in the Table. Tranylcypromine caused a marked increase in tyramine sensitivity, whereas milacemide was indistinguishable from placebo in this respect. We conclude that there is no evidence for an interaction of milacemide with tyramine. T30 values milacemide group tranylcypromine group Day 0 Day 18 Day 21 Day 0 .Da~ " 18 Day 21 Mean (SD)

5.0 1.8

4.6 1.4

4~7 1.4

4.2 1.1

3.9 1.0

***0.7 0.2

MEASUREMENT OF AMITRIPTYLINE SERUM CONCENTRATION IN DEPRESSIVE PATIENTS M. Munjiza Serum concentrations measurement of amitriptyline has the cilinicar value in monitoring: patients who do not respond to usual oral doses, in high risk patients because of ther age or concurrent illness, when drug interaction or noncompliance are suspected of causing poor patients responce, when the dose required to achieve therapeutic range exceedsthe recommended limit etc. The main charcteristic of the method is a homogenious enzyme immunocessay based on the competition between drug in the sample eluate and enzyme-labeled drug (G6PDH) for antibody bindir~g sites. Enzype activity is measured spectrophotometHcally because it converts NAO to NADH, visible on 340 nm, and those changesa r e proportional to drug concentration. We standardized our method (elut[on, manipupation with wluate, multiplication factor on spectrophptpmeter etc.), and eventually we obtained a smooth standard curve on vicyclic semilogaritm graph papaer. The adequate correlation of the results was shown by the valuesof both standards on the obtained standard curve. The group consisted of 34 adult depressive patients (28 femates, 6 males) wthout any liver or kidney disease.All of them were treated with amkriptytine longer than two weeks: They were all hospitalized or partly hospitalized patients. The drug was orally administred (Amyzol pills a 10 or 25 mg.). Minimal daily dose was 30 rag, maximal 150 mg. all patients used benzodiazepinesalso. Four patients (11,8%) had unmeasurable coneetrations and 2 were overdosed. After consUlting with the therapeutist the testings of patients with a poor correiationn betweendiiy doseand serum concentration were repeated. The obtained results pointed out that this method could be used in any laboratory equiped with a spectrophotometer which has a visible spectre and qives reproducible results. Measurablevaluesare between 7.96 x 10 - 9 mol/I and 79.6 x 18 - 9 mol/I and recommended therapeutic concentrations are 16 x 10 - 9 to 48 x 10 -9 mol/L evaluctingthe results obtained we came to the conclusion that the measurement of amitrip-tyline concentration had its clinical value. The cfearence (dily dose mg/serum concetration ng/ml) was calculated for all patients except for these whose serum concetration could not be measuredor for these who had an extremely bad correlation (3). The clearance was C = 0.63 - 1.31. Institute for Mental Health, Department of Clinical Psychophar-macology, Belgrade,Palmoticeva 37, Yugoslavia

EFFICACY OF PAROXETINE IN THE TREATMENT OF MAJOR DEPRESSION RESISTANT TO CONVENTIONAL ANTIDEPRESSANTS F.G.M. MOiler, C.A. Gagiano, J. F o u r i and J.F. Le Roux AIM

A six week, open efficacy and tolerabllity study was carried out in 28 patients (7 males and 21 females all younger than 65 years) who fulfilled the 0SM-111 diagnostic criteria for depression. All had a Hamilton Depression Rating (HAMD) score of 18 or more while receiving alternative antidepressants and entered the study without a washout period. HAMD scores were measured at the end of weeks 1, 2, 4 and 6. Patients received 20 or 30mg paroxetine/day as a single dose ingested with breakfast. RESULTS Eighteen patients completed the 6 week study; 6 were withdrawn because of poor therapeutic response; 2 withdrew for non-drug related reasons. A good therapeutic response was observed in 69.2% of patients, os whom the majority had been receiving amitriptyline. The mean pretreatment scores for paroxetina responders and non-responders were 23.5 and 25.1, respectively. The mean score for responders fell to 10.6 within 2 weeks and to 6.4 at 6 weeks. Paroxetine was generally well tolerated. The main adverse events included constipation, dry mouth and drowsiness. CONCLUSION Paroxetine may be of therapeutic value in patients failing to respond to other antidepressants, notably amitriptyline. Dept. of Psychiatry, University of the Orange Free State PO Box 339, Bloemfontein, South Africa

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EFFECT OF FLUVOXAMINETREATMENTON BODYWEIGHT M. D'Armiento, E.A. Jannini and M. Ciampini The role of serotoninergic neurotransmission in the regulation of food intake is well established. Aim of the present study was to evaluate the effect of fluvoxamine, a new antidepressant drug that selectively inhibits the re-uptake of 5-HT, on body weight in a population of obese depressed or non-depressed outpatients. 20 females (aged 18-57 yrs) with BMI between 25 and 40 were included into the study. They were divided in two groups of lO patients each, i . e . depressed or not, based on Hamilton test (HT). A further subdivision was made on the basis of Dutch Eating Behavior Questionnaire (DEBQ): 7 patients in each group were treated with 50mg f]uvoxamine per os, given once daily at lO.O0 p.m., while the other 3 received placebo in a double-blind fashion. Treatment duration was 45 days. Before starting the treatment, after approximately 14 and 28 days and at the end were checked: HT, OEBQ, body weight, BMI, blood pressure (both clino- and orthostatic) and any side-effect. 3 drop-outs occurred, all being treated with fluvoxamine. The analysis of the results showed, at the end of the study period, an overall improvement of depression symptoms in fluvoxamine-treated patients; of them, 47% showed a statist i c a l l y significant reduction of body weight and BMI, i r respective of the severity of their obesity at study entry. In our opinion, fluvoxamine may be helpful in the treatment of obese patients in which the increase in body weight is associated with depression symptoms. Chair of Endocrinology, University of L'Aquila, 67100 L'Aquila, I t a l y .

EFFECTS OF SINGLE DOSES OF 50 mg ATENOLOLAND 0.25 mg TR!AZOLAM ON RESPONSESTO DELAYED AUDITORY FEEDBACK. D. Enterling, C. de Mey and I. Meineke. The effects of 5 ~ reading a randomly selected t e x t under delayed auditoryfeedback (DAF), on heart rate (HR), blood pressure (SBP/DBP) and plasma catecholamines (NE & E), were assessed in 6 normal subjects, 150 min after an oral dose of 50 mg atenolol (A), 0.25 mg triazolam (T) or matched placebo (P). Treatments were allocated in doubleblind fashion and period-balanced cross-over design. Under P, 10 min s i t t i n g immediately p r i o r to DAF, caused an average rise of +6 bpm in HR, +7 mmHg in %BP and DBP, +0.22 nM of plasma NE and +0.11 nM of plasma E, vs the supine resting state. Treatment with A tended to decrease this postural HR-response (A-P: -4.5 mmHg, 95% CI: -g.2 to 0.3), but had l i t t l e effect on the further responses. Treatment T had l i t t l e effect on the postural responses but tended to reduce supine E-levels p r i o r to testing (TP: -.053, 95% CI: -.108 to 0.003). After P, 5 min DAF in s i t t i n g position caused a +14 bpm rise of HR, and +9/+17 mmHg rise of SBP/DBP; NE rose +0.33 nM and E +0.03 nM, r e l a t i v e to pre-test s i t t i n g . Treatment A tended to decrease the HR-response (A-P: -5.4 mmHg, 95% CI: -12.5 to 1.7), to enhance the SBP-response (A-P: +4.5, 95% CI:-2.5 to 11.5) but hardly affected the DBP-response (A-P: -2.1, 95% CI: -10.0 to 5.9); the NE-response was not affected, but the E-response was larger (A-P: +0.20, 95% CI: 0.01 to 0.40). Treatment T had l i t t l e effect on these responses. Performance q u a l i t y under DAF was not formally assessed, but T-treated subjects appeared to read more f l u e n t l y , whilst appearing more sedated and detached. We conclude that: i) larger sample sizes are needed to reduce the risk of Type I I error caused by the large residual errors on these (postural and DAF) responses, 2) postural changes have to be accounted for during DAF-test, 3) within the present constraints, the increased adrenaline response to mental stress after 50 mg atenolol is to be highlighted, even when devoid of immediatecirculatory effect. SK&F-Institute Appl. Clin. Pharmacel., SKD, G~ttingen, FRG

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INTERACTIONS OF PSYCHOTROPIC DRUGS ON HUMAN PERFORMANCE AND MOOD: SINGLE DOSES OF ORG 3770, AMITRIPTYLINE, AND DIAZEPAM M.E. Mattila 1, M.C. Vrijmoed-de Vries3, and M.J. Mattilal'_~2 Actions and interactions with diazepam of two different antidepressants on human skilled performance and mood were studied in a randomized double-blind crossover trial with single oral doses of placebo, 50 mg amitriptyline (AMI) and 15 mg Org 3770, given alone and in combination with 15 mg diazepam (DZ) to 12 young healthy subjects at one-week intervals. Objective tests for coordinative, reactive and cognitive skills, and subjective assessments (visual analogue scales) were performed and venous blood sampled at baseline and L5, 3, 4.5 and 6 hours post treatment. Placebo hardly affected performance and mood. DZ, in contrast to previous studies, only prolonged choice reaction times and caused exophoria, and proved sedative in the sujecrive tests. AMI produced sedation and impaired coordination, attention and cognitive performance (digit substitution), most clearly at 3 to 4.5 hours. ORG 3770 resembled AMI in impairing objective and subjective performance and having no effects on choice reaction time. However, ORG 3770 did not impair coordination, whereas AMI did. Their combined effects with DZ were additive in objective tests but subadditive in subjective tests. The drug combinations, but not any single drug, impaired learning acquisition. Plasma concentrations were in the expected range. We conclude that the different pharmacological profiles of "equisedative" antidepressants may lead to varying decrements in objective psychomotor tests. The combination of DZ with the antidepressants used in this study impair skilled performance but may not cause major problems. Departments of 1 Pharmacology and Toxicology, and 2 Clinical Pharmacology, University of Helsinki, Finland. 3Organon International B.V., Medical R&D Unit, Oss, The Netherlands.

OF PANIC D~SORDER WITH ALPRAZOLAM AND IMIPRAMIN-COMPARISON OF EFFICACY AND TOLERABL!TY H.Heikkinen, U. Lepola Promising results of alprazolam i n relieving panic attacks and those indicating some antidepressant efficacy have been published. In this nine weeks double blind study following a matched pair randomization we compared the antipanic effect and tolerability of alprazolam and imipramin by registering attac frequency and asking for adverse effects. To evaluate the effects of these drugs on anxiety and depression often involved in panic disorder, Hamilton Rating Scale for Anxiety (HAM-A) and Montgomery-~sberg Depression Rating Scale (MADRS) were completed at the beginning of the treatment and after three and nine weeks. 56 out-patients with an anamnesis of panic attacks were included. 55 of the patients (31 women and 24 men, age 37 • 9.5 years) met the diagnosis of DSNIII for panic disorder and had suffe[ed from panic attacks for ~t least three months. Both dr~l~s ~ c r e a ~ e d the ~ttack fre.quency: alprazolam from 17 f 12.3 to 5 • 14.6 attacks, imipramin from 21 • 23.4 to 2 • 6.6 attacks per three weeks. The HAM-A scores decreased in the alprazolam group from 22 • 6.4 to 9 • 9.2 (pK0.001) and in the imipramin group from 23 • 8.5 to 9 • 9.1 (p<0.001).The scores on M~DRS decreased from 9 • 4.6 to 4 • 5.6 (p<0.001) and 9 • 6.6 to 3 • 5.0 (p<0.001) in the alprazolam and the imipramin groups, respectively. The tolerability of alprazolam seems to be better than that of imipramih. In conclusion, both alprazolam and imipramin were found to be effective antipanic agents. The terapeutic action of both drugs on the frequency of panic attacs, generalized anxiety and depressive symptoms occured in concert. Vaajasalo Hospital and Medical Department, Orion Pharmaceutica, P.O.Box 65, SF-02101 Espoo TREATMENT

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PSYCHODYNAMICS AND KINETICS AFTER BUCCAL AND ORAL ADMINISTRATION OF THE ANTIPANIC PARTIAL BENZODIAZEPINE (BZ) AGONIST RO 16-6028 R. Gieschke, R. Pricker, G. Roncari, W.H. Ziegler RO 16-6028, partial agonist at the BZ-receptor, is currently under investigation for the treatment of panic disorders. We have studied the pharmacokinetics of RO 166028 and its relationship to dynamics particularly considering the early phase of absorption. Six healthy male subjects (fasting) received 2 mg of RO 16-6028 as oral tablet and as buccal aqueous solution on two occasions in an open randomized two-way cross-over design. The aqueous solution was expelled i0 min after administration. Phenol red was used as a marker to determine the absorbed fraction of the dissolved dose. Pharmacodynamic measurements included the DSST and subjective ratings on visual analogue scales for sedation, muscle relaxation, concentration ability and 'drug feeling'. Maximal psychometric effects and peak plasma concentrations after oral dosage were higher than after buccal administration reaching statistical significance in DSST, 'drug feeling' and plasma concentratiO~So No significant differences were observed in timepoints of maximum effect and maximum concentration and in duration of effects. Hysteresis loops combining drug concentrations and effects in DSST showed no differences between the two administration routes. Sensitivity to RO 16-6028 was comparable in five and considerably increased in one subject. During early phase of absorption (20 min) pharmacokinetic parameters differed widely between and within the two administration routes. However, these variations were individually well reflected by pharmacodynamic parameters~ Thus, the absorption of RO 16-6028 following buccal administration is as rapid as after oral dosage on an empty stomach. The buccal route may be useful in treatment of panic disorders. Division of Clinical Pharmacology, Department of Medicine University Hospital, CH-8091 Zurich.

PSYCHOACTIVE DRUGS AND THE CLINICAL TEST FOR DRUNKENNESS T. Kuitunen. M.J. Mattila and T. Sepp/il~ Clinical test for drunkenness (CTD) evaluates alcohol-induced impairment of driving fitness. We conducted two placebo-controlled randomized double blind crossover trials, 12 subjects in each, to study the effects of therapeutic single doses of psychoactive drugs on the standard CTD test which comprised motor (walking with eyes open and closed, gait in turning, finger to finger, collecting small objects), vestibular (Romberg with eyes open and closed, nystagmus) and mental tests (subtraction as to time, subtraction backwards). The tracking error severity index (TESI) and cumulative reaction times (RT) were recorded as variables of simulated driving used as a reference "machine" test. In Trial I, 15 mg diazepam, 50 mg amitriptyline and 15 mg Org 3770 each alone showed minor effects in the CTD. The combination of diazepam and Org 3770 caused strongest impairment in motor subtests as compared to placebo or either drag alone. M e drag combinations impaired TESI and RT up to 6 h while single drugs wgre less effective, yet subjectively sedative. In Trial II, 0.8 g/kg ethanol alone significantly impaired motor and vestibular CTD subtests while 7.5 mg zopiclone and 0.25 nag triazolam alone showed minor effects. Single drug effects were significant at 2 h only while the hypnotic-ethanol combinations impaired performance up to 5 h.TESI and RT proved more sensitive to hypnotic drugs than to ethanol, and the hypnotic-ethanol combinations showed an additive effect on these functions. Thus, the CrD detects ethanol and drug+ ethanol effects better than those of single drugs or drugdrug combinations while simulated driving easily detects coordinative and reactive impairments. Department of Clinical Pharmacology, University of Helsinki, Paasikivenkatu 4, SF-00250 Helsinki, Finland

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COMPARISON OF THE MOCLOBLM!DE-ET~L~NOL AND CLOMIPRA~MINEETHANOL INTERACTION IN HEALTHY SUBJECTS. A.Cournot, I.Berlin, R.Manfredi, AM.Pedarriosse, P.Molinier, A.J.Puech and R.Zimmer. Therapharm Recherches,19, rue de la Tour,75016 Paris, Dept. of Clinical Pharmacology, Hop.de la Salp~tri&re, 47,Bd de l'H$pital, 75013 Paris, Produits Roche, 52, Bd du Pare, 92521 Neuilly/Seine, Hoffmann-La Roche Ltd. Ch-4002, Basle. The interaction of clomipramine (C) and moclobemide (M, new reversible MAOI-A) with ethanol was compared in a double blind 2 parallel groups study in 24 healthy volunteers.M was given in therapeutic dose (200 mg t.i.d.) but C in subtherapeutic dose (25 mg b.i.d.) because of its poor tolerance in healthy subjects. Psychometric evaluations were performed during a placebo run-in and after a 5 day's treatment period before, lh and 4h after ethanol ingestion. Ethanol doses were pre-determined for each subject in order to produce an alceholemia of 0.6 g/L and this dose was given on the days of evaluations. The day before ethanol ingestion somatic measures were made to assess antieholinergic effects of the drugs. Ethanol significantly increased body sway, decreased vigilance (decreased critical flicker fusion frequency and digit s)~mbol substitution, prolonged choice reaction time), impaired memory tasks and increased satisfaction and tension of the subjects. Drugs potentialized the effect of ethanol on memory tasks, body sway and critical fusion frequency. C without ethanol increased body sway, prolonged choice reaction time and with ethanol potentialized the effec~ of ethanol on these tests. Subjects on C were less relaxed and after ethanol they had more adverse effects than subjects in the M group. No clinically relevant changes occured in blood pressure and heart rate. Salivary excretion was blocked only by C. Conclusion : There were no important psychometric differences between M (full therapeutic dose) and C (subtherapeutic dose) with respect to their interaction with ethanol but C, contrary to M, showed clear anticholinergic effects and a poor tolerance.

EFFECTS OF ALFENTANIL, FENTANYL AND MORPHINE BOLUSESON AN EXPERIMENTAL PAIN MODEL IN HUMANSUBJECTS

Male volunteers (ages 21-40) were employed in t h i s study o f r e l a t i o n s h i p s between plasma concentration and analgesic effect of alfentanil, fentanyl and~morphine. We used electrical tooth pulp stimulation to produce experimental pain and measured subjective pain report (PR) and evoked potential (EP) amplitude at vertex. On each test day, stimulus intensity was set at the level producing strong pain. During a baseline period, we delivered 150 stimuli and the subject reported pain intensity after each block of 50 t r i a l s . Immediately after baseline, a|fentanil (15mcg/kg), fentanyl (2mcg/kg), morphine (142mcg/kg), or saline was injected over 60 sec. Testing was then repeated, exactly as during baseline, in 6 epochs over the next 2 hours. Blood samples were drawn from 1-300 min after injection for drug concentration assays. Alfentanil produced an immediate decrease in EP and PR with peak effects at about 2 min after injection and duration of effects of about 20 min. Effects of fentanyl on EP amplitude and PR were maximal between 5 and 25 min and recovery was complete within 60 min. Morphine clearly affected both measures but the effect was poorly defined. With alfentanil, analgesic effect magnitude paralleled closely the changing plasma concentration of the drug after the bolus. In contrast, there was appreciable lag between plasma fentany] concentration end effect. Effects of morphine were not clearly related to plasma concentration. These results may reflect differential clearance of the 3 opioids from the central nervous system in humans. Pain and Toxicity Research AB-122, Fred Hutchinson Cancer Research Center, Seattle, Washington, 98104 U.S.A.

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A SI"UDu 70 COMPARETHE USE Of: KETOROLAC AND PETHIDINE: IN LABOUR PAIN.

U n i v e r s i t y Department o f Obstetr:[cs and Gynaec:olocly, Glasgow Royal Maternity Hospital, Rottenrow, Glasgow, G41 2EE, United Kingdom.

DEMONSTRATION OF BETA 1 SELECTIVITY OF METOPROLOL CR/ZOK USING TERBUTALINE-INDUCED CHANGES IN PLASMA GLUCOSE AND POTASSIUM. _M,J. Kendall, S. Akhlagi and H. Lewis Beta1-selective beta blockers cause less beta2-adverse effects and are preferable. However, several methods of demonstrating selectivity in man are difficult and not very reproducible. An alternative is to use terbutaline, a selective beta2 agonist which causes a rise in plasma glucose, a fall in plasma potassium and in diastolic blood pressure. The impact of beta blockers on these processes may be used to assess selectivity (Br J clin Pharmac 1983;16:557-560). Could this method be used to determine whether a controlled-release beta 1-selective drug, metoprolol CR/ZOK (MCR), by produc;ng lower plasma concentrations, is more selective than conventional metoprolol (M) and atenolol (A) each at a dose of 100 mg?. In 12 healthy volunteers, a terbutaiine infusion of 6pg/kg was given i.v. over one hour on 4 occasions. 3.5 hours before the infusion they were given MCR, M, A or placebo in random order singleblind. Mean adjusted reductions in plasma potassium concentrations (K +) (mmol/I) at the end of the infusion were after MCR=-0.64, M=-0.35, A=-0.30, pl=-1.02. The reductions in K+ was significantly greater after MCR than after M (p=0.005) and A (p=0.001). For glucose (mmol/I) the corresponding increases were MCR=0.46, M=0.14, A=0.06, pl=1.08. MCR differed from M and from A (p=0.03). Conclusion- (1) The terbutaline infusion test is a useful simple test for betal-selectivity. (2) Keeping plasma concentrations low improves selectivity, an advantage of m e t o p r o l o l C R / Z O K demonstrable by this technique. Department of Pharmacology, Medical School, Birmingham B15 2TJ, United Kingdom.

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THE RELATIONSHIP BETWEEN SERUM MEPERIDINE LEVELS AND ANALGESIC RESPONSE IN POSTSURGICAL PATIENTS USING PATIENT-CONTROLLED ANALGESIA VERSUS INTRAMUSCULAR DOSING T.J. Baumann, M.A. Smythej B_~.Marikis, B.A. Bivins This investigation examined the relationship between serum meperidine eoneentrations and analgesic response in postsurgieal patients allowed to use patientc o n t r o l l e d a n a l g e s i a (PCA) and c o m p a r e d t h e m to patients reeeiving conventional intramuscular (IM) dosing. Six patients who had undergone abdominal surgery were randomly entered into this trial (3 PCA 3 IM). A sequence of 5-point pain and sedation rankings and serum meperidine levels were obtained in all patients the day after surgery. Minimum effective concentration (MEC) was defined as the level of meperidine at which patients felt pain relief as indicated b y a decrease in pain rankings. The MECs for all PeA patients ranked from 192 to 478 ng/ml (296 +/I13) and approached statistical difference from those seen in the IM patients, 398 to 724 ng/ml (551 +/- 164) with P<0.]0. Mean maximum change in meperidine concentrations in PCA patients (177 +/- 88 ng/ml) was significantly different than the IM group (484 +/- 125 ng/ml), P<.05 and ranged from l]J to 499 and 91 to 753 ng/ml respectively. Mean maximum changes in both pain and s e d a t i o n s c o r e s for PCA p a t i e n t s were not significantly different than those recorded in IM patients. During this investigation, PCA patients experienced smaller swings in meperidine levels than IM patients. This was true despite no differences in maximum change in pain and sedation scoring. Minimum effective concentration analysis suggests postsurgical abdominal patients using P C A m a y experience pain relief at meperidine levels lower than those needed in patients receiviug IM injections. D e p a r t m e n t of P h a r m a e y P r a c t i c e , W a y n e S t a t e University~ Departments of Surgery and Pharmacy Services, Henry Ford Hospital, Detroit, MI. 48202

N E W S L O W - R E L E A S E M E T O P R O L O L E Q U I P O T E N T TO A T E N O L O L IN M I L D TO M O D E R A T E H Y P E R T E N S I O N T. M e n z e l A r a n d o m i z e d d o u b l e - b l i n d p a r a l l e l g r o u p study was p e r f o r m e d to c o m p a r e the e f f i c a c y of a n e w m e t o p r o l o l f o r m u l a t i o n (M) ( m e t e p r o l o l succinate) w i t h a t e n o l o l (A) in the t r e a t m e n t of m i l d to m o d e r a t e h y p e r t e n s i o n . A f t e r a 2 weeks' p l a c e b o r u n - i n p e r i o d p a t i e n t s w i t h s u p i n e DHP 95 nun Hg w e r e r a n d o m l y a l l o c a t e d to an 8 weeks' t r e a t m e n t w i t h 50 m g M (n = 97) or 50 m g A (n = 95) o n c e daily. A l l m e a s u r e m e n t s w e r e p e r f o r m e d 24 h a f t e r d r u g intake. F o u r weeks' t r e a t m e n t d e c r e a s e d s u p i n e BP f r o m 1 6 6 . 5 / 1 0 1 . 6 to 1 4 9 . 0 / 9 0 . 5 m m Hg on M and f r o m 1 6 6 . 4 / 1 0 2 . 0 to 1 5 0 . 7 / 9 1 . 8 m m Hg on A. M l o w e r e d e x e r c i s e BP (6 min. w i t h 2 min. on 50, 75 and i00 Watt, reap.) b y 1 9 . 7 / 1 1 . 6 m m Hg, A by 1 6 . 8 / 1 0 . 1 m m Hg. BP c o n t r o l (supine H P ~ 90 m m Hg) w a s a c h i e v e d in 66 % on 50 m g M and in 54 % on 50 mg A. S u b s e q u e n t l y , m o s t of the nonr e s p o n d e r s r e c e i v e d the d o u b l e dose. C o m p a r e d to b a s e l i n e , s u p i n e BP a f t e r 8 weeks' h i g h or low d o s e t r e a t m e n t w a s 1 4 3 . 6 / 8 6 . 7 m m Hg on M and 1 4 6 . 9 / 8 8 . 4 m m Hg on A. A l s o 8 weeks' e x e r c i s e BP r e d u c t i o n w a s m o r e p r o n o u n c e d w i t h a dec r e a s e of 2 6 . 8 / 1 5 . 9 nun Hg in the M g r o u p and 2 2 . 5 / 1 2 . 7 m m Hg in the A group. For all m e a s u r e m e n t s the d i f f e r e n c e s b e t w e e n the d r u g s w e r e not s i g n i f i c a n t , i n d i c a t i n g t h a t 50 (i00) m g of M are e q u i p o t e n t to 50 (i00) mg of A in t r e a t m e n t of h y p e r t e n s i o n . B o t h t r e a t m e n t s w e r e w e l l t o l e r a t e d w i t h 14 p a t i e n t s w i t h a d v e r s e e v e n t s on M and 16 on A, r e s p e c t i v e l y . M C - s t u d y g r o u p for p h a r m a c o t h e r a p e u t i c r e s e a r c h , T. M e n z e l , R o t h e n b a u m c h a u s s e e 119, D - 2 0 0 0 Hamb u r g 13

L_io..y_d.,__..Z..;._~_~ 1 '~.eL__..~ ._J.)_L_a.:g h n .s_~.~,r_~,_..~.._L. B_u.!.}~i.O.~h~.m.,__~i. S....... The o b j e c t i v e of t h i s study was to compare the e f f i c a c y of intramuscular doses o f e i t h e r I0 mg ketorolac tromethamine (KT) or 50 mg or 100 mg pethidine (P). KI is a prostaglandin synthetase i n h i b i t o r . The study was a double,,-bh[nd, single dose randomised study. The patients were parous women e i t h e r in spontaneous labour or admitted f o r induct:i.on oF labour. Pain :[r~tensity (on verbal and v i s u a l analygue scales), and sedation were assessed at entry and then at 0.5, I , 1.5, 2, 3, 4, 5 and 6 hours post dose, or" u n t i l d e l i v e r y or a d m i n i s t r a t i o n of f u r t h e r analgesia. Apgar scores f o r the neonate were obtained at deliwery and were repeated l a t e r i f low. 128 women entered the study, The analqes:[c e f f i c a c y was analysed f o r 2 hours post dose as the major:i.ty of babies (58%), were d e l i v e r e d by then, The analysis showed s t a t i s t i c a l l y superior e f f i c a c y f o r pethidine compared with ketorolac 10 nlg. The pethidine doses were not s t a t i s t i c a l l y d i s t i n g u i s h e d and both doses had poor e f f i c a c y in t h i s s i t u a t i o n . No adverse events were recorded f o r any mother or [:oetus. Maternal sedation and f o e t a l depression were s t a t i s t i c a l l y less in the ketorolac group.

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THE 6-RECEPTOR OCCUPANCY AS A MEASURE OF DRUG ACTIVITY IN PLASMA T.Kaila, I.Kantela, E. Iisalo The betablocking drugs exert their actions by binding to the 8~- and 62-adrenergic receptors. We quantitated the betaz- ( ~ - R O ) and beta2rece ptot occupancy (~2-RO) in plasma of several betablocking drugs after their oral administration using radioligand binding technics. Fifteen healthy male volunteers received a single dose of placebo, acebutolol, atenolol, boplndolol, metoprolol, pindolol or propranolol in a randomized cross-over fashion study. The doses were based on clinical impression about che equal beta~ blocking effect. Drug Dose Conc.ng/mg -RO% ~2-RO% Ace. 200 mg 500+290 54 5+16.4 49.3+20.6 i0.7~ 3.6 Ate. 50 mg 230+85 61 i~ 8.1 79.7~ii.8 Bop. i mg 3.1TI.2 54 5T 9.6 Met. 50 mg 77~50 66 7+12.8 16.5+14.4 98.3+ 0.5 Pin. 7.5 mg 35+6.9 97 4+ 0.8 96.5+ i.4 Pro. 80 mg 52+27 75 8+ 8.4

PHARMACOKINETIC AND PHARMACODYNAMIC EVALUATION OF METOPROLOL CONTROLLED RELEASE (CR) 50 MG. I Wieselgren 7 P Lundbor.q, A Sandberg, B Olofsson, R Bergstrand. Metoprolol CR is a multiple-unit controlled-release preparation for oncedaily dosing. In this placebo-centrolled steady-state study in 12 healthy male volunteers, a low dose (50 mg) of metoprolol CR (CRS0) was compared with a conventional metoprofol tablet (CT50) after once-daily dosing for 5 days. Methods: On Day 5, plasma samples were frequently taken and the [~f-antag~ effect (E) was measured as the per cent reduction in exercise heart rate relative to placebo baseline (bicycle ergometer test) during 24 hours after dose. Results: CR50 showed an even 24-hour plasma concentration profile in all subjects, with a lower peak concentration (Cmax), a higher trough concentration (Cmin) and less variation of plasma levels (fluctuation index) over the dosage interval as compared to CT50. The bioavailability (AUC) did not differ significantly between the two preparations. The pattern of ~1 -blocking effect rellected the plasma concentration curve and was maintained at a more constant level over the 24-hour period after CR50. Thus, both the maximum (Emax) and minimum (Emin) effect differed significantly between the two treatments. CR5O produced a better total effect over the 24-hour interval than did CR50, as indicated by the significantly

tligher ~rea under effect curve (AUEC;)values.

Pla

The ~ - R O was in accordance with the cllnical impression. However, the ~z-RO after pindolol was extremely high. The 8z-RO after atenolol was smaller than that of metoprolol. After acebutolol the 82-RO was almost as high as the ~t-RO. Diaeetolol and other metabolites with ~z-blocking activity probably explain the phenomenon. In conclusion, by measuring ~t-RO and 82-R0 in vitro, a picture of drug activity in plasma is obtained which is based on the mechaisms of drug action. Department of Clinical Pharmacology and Medicine, Turku University, SF-20520 Turku, Finland.

Mean Cmin

Cmax

FI*

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A P L A C E B O - C O N T R O L L E D STUDY ON THE EFFICACY AND T O L E R A B I L I T Y OF A C O N T R O L L E D - R E L E A S E FORMULATION OF METOPROLOL 50 MG IN HYPERTENSIVE PATIENTS AGED 60-80 YEARS. A. J~tte]~ In a double-blind randomised study with parallel groups 34 elderly hypertensive patients (60-80 years) received either placebo or 50 mg once daily of a new controlled-release (CR) formulation of metoprolol for 4 weeks. In c o m p a r i s o n with the placebo group, supine DBP was significantly more reduced in the metoprolol CR group 24 hours after dose intake: - 7 . 9 mmHg in the metoprolol group vs -1.8 mmHg in the placebo group (p=0.042; 95% C1=-12.1, -0.2). Reductions in SBP and HR did not differ significantly b e t w e e n the g r o u p s : - 6 . 4 vs - 6 . 0 mmHg and - 9 . 2 vs -7.4 beats/min, respectively. Fiftynine percent (59%) of the metoprolol CR group and 18% of the placebo group had a DBP <95 mmHg with a concomitant reduction >5 mmHg (p=0.032). The tolerability of the 50 mg dose of metopro]ol CR was good and equalled that of placebo. In conclusion, metoprolol CR 50 mg once daily appears to be an effective dose in the treatment of elderly hypertensive patients. Jorv Hospital, Espoo, Finland

EFFICACY AND TOLERANCE OF A NEW CONTROLLEDRELEASE FORMULATION OF METOPROLOL, ONCE DAILY, COMPARED TO CONVENTIONAL TABLETS, TWICE DAILY, IN MiLD TO MODERATE HYPERTENSION. M. Moore, presenting on behalf of a Canadian muIticentre group. In a randomised double-blind MC study in hypertensive patients (n=77), the antihypertensive effect of once-daily (o.d,) dosing with a new controlled-release (CR) formulation of metoprolol was compared with that of twice-daily (b.d.) dosing with metoprolol conventional tablets, 24 hours after dose. The treatment duration was 8 weeks with a starting dose of 100 mg in the CR group and 50 mg b.d. in the tablet group. At the end of the first 4-week period, the dose was increased to 200 mg o.d. and 100 mg b.d, respectively, in nonresponders (DBP>95 mmHg). SBP, DBP and HR were reduced compared to baseline in both treatment groups after both 4 and 8 weeks' therapy. Although there was a tendency for a greater effect following CR administration (mean reduction in DBP: 18.5 vs 13.6 mmHg at week 4; 19.7 vs 14.0 mmHg at week 8, respectively), there was no statistically significant difference in either SBP, DBP or HR between the treat-ment groups. Nor was there any difference in the percentage of responders. After 4 weeks 85% of the CR group and 74% of the tablet group had DBP<95 mmHg. After a further 4 weeks, the corresponding figures were 93% and 93%. Both treatments were equally well tolerated. In conclusion, the antihypertensive effect of once-daily dosing (100-200 rag) with the new CR formulation of metoprolol appears to be at least as effective as that of twice-daily dosing (50-100 mg) with conventional metoprolol tablets. AB Hassle, S-431 63 M~lndal, Sweden.

(SD) (nmol/I) (nmol/I) (~

AUC24

(nmol-h/I)

Emin

(%)

Emax

(%)

AUEC24

(%'h)

CR50 39(50) 71(78)

69(24) 1312(1548) 9.0(9.2) 13.6(7.8) 250(197) CT50 6(16) 221(157) 529(18't) 1364(1571) 0.4-(6.8) 1g.1(6.3) 149(181) * FI

Crnax - Cmin

x 100; ~=24h

AUC/'~ Conclusion: Once-daily administration of metoprolol CR 50rag to healthy subjects resulted in smooth plasma concentration and produced a ~1 -blocking effect for 24 hours in most of the subjects. CR50 once daily might therefore be a valuable and clinically effective dose. Research Laboratories, AB Hassle, S-431 83 M61ndal, Sweden

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COMPARISON OF TWO LONG ACTING PREPARATIONS OF METOPROLOL ON AMBULATORY ELECTROCARDIOGRAPHY IN HEALTHY VOLONTEERS 1P. Kantelip (1), P. ~ - M a r u l l a z (2), 3.5. Lecaillon (3) and F. Badin (3) 1~ de Pharmacologte, Explorations Fonctionnelles C~r@brale: et Respiratoire (Prof. Magnn) O-R 25030 B e ~ Cedex, 2 INSERM U 195 Fac. Md=~mine 63001 Clermont-Ferrand Cedex, 3 ~=~:iic,'aland P~rmao:~dnettc Depar~rrents Lab. CIBA GEIGY, Reuil Ma~raison, FRANCE.

THE ACUTE EFFECTS OF ORAL DILEVALOL (SCH 19927) ON PLASMA NORADKENALINE KINETICS AND PLASMA LIPOPROTEIN CHOLESTEROL LEVELS L.G. Howes~ H. Krum and W.J. Louis Plasma noradrenaline (NA) kinetics were measured in arterialized blood following a constant one hour intravenous infusion of L-ring[3H]NA (i.i TBq/rmnol, NEN) (total dose 2 mBq) in 15 normotensive volunteers 3 hours following the oral administration of placebo, 200 mg or 400 mg of dilevalol in a randomized crossover study. Plasma total, HDL and LDL cholesterol were also measured 3 hours post dose. Dilevalol had no effect on supine blood pressures or heart rate but caused a significant fall in systolic blood pressure following standing and attenuated the rise in diastolic blood pressure and heart rate that usually accompanies standing. Acute dilevalol administration did not significantly alter plasma lipoprotein cholesterol levels, indicating that the beneficial effect of dilevalol on plasma lipoproteins requires chronic administration. Dilevalol significantly (p < 0.025) increased plasma NA levels in a dose dependent manner (placebo 1.18 • 0.51 nmol, 200 rag: 1.60 • 0.53 rnnol/l, 400 mg: 1.91 • i.i; Mean • SD) due to a significant (p < 0.01) increase in NA spillover (placebo: 0.99 ! 0.48 nmol/min/m 2, 200 mg: 1.35 ! 0.37, 400 mg: 1.74 • 0.90). In contrast, NA clearance remained unaltered (placebo: 0.85 • 0.25 i/min/m z, 200 mg: 0.85 • 0.37, 400 mg: 0.96 • 0.36). Supine plasma DHPG (a neuronal metabolite of NA) also increased following dilevalol (placebo: 4.89 • 1.73 nmol/l, 200 mg: 8.14 • 4.50, 400 mg: 7.~4 • 3.14) indicating that the increase in NA spillover was not due to the blockade of neuronal uptake. Acute dilevalol increases plasma NA levels by increasing sympathetic activity, possibly by baroreceptor activation or stimulation of pre-synaptic beta-2 receptors.

The effects of heart rate and on the pharmacckinetlc pararreters ef metoprolol were ca'rl~ared dunng repeated aOninBtrauon of 1~/190 metq>colol OROS and 200 rrg LOPRESSOR S.R.o.d. for 10 days. Nne healthy rmde volunteers received each fcrrmlation and placebo in a three period cross over desig~l study under double blind c'~xlitic~ Heart rate w&s continuously recorded over 24 h (l-biter rnorutormg) on days 1,3,5,7,10 during the trealraent and on the llth, 13th and ISth days. Pla.~ra sarrples were taken after ad-ninkstrationon days 1 and 10 over 2~ and 36h, resl:ectively, and on days 3, 5 and 7 just before dosing and 6 h after dosrg. The concentrattor~s of metqurolol were ~ by an t-PI.C method and expre.,r:,ednn tetr~ of free bases. Decrease in diurnal beart rate was obtained earlier w~th SR tablets (1 h : 9 %) tYan with OROS tablets. Significant decrease in nocturnal l-eart rate was ob~ after 3 days of treatment with OROS tablets (13 %) and after 7 days with SR tablets (13 %) Steady .state effect on rrean heart rate (i 6 %) over 24 h and steady .state metoprolol co~entrat~orts were nearly obtained after 3 or 5 days of trea~ffnentwith th~ 2 forcaMtiorts.Alt]-ough there was no dilferer~e in bradycardac eIIects at steady state, pr^ed~n~ cor~_'entrations were higher with the 1g/190 metoprolel OROS tablets (231 - 152 nmol/l) than with the S.P,, tablets ( (:9.3+ 85.8 rrnol/l). Fltm'ttations of plam'a cxmcentraUons dtring a dosing interval was ~ m,aller for Its/190 metoprolol OROS tablets than for the S.R. tablets. After cessation el the treatrrent with metoprolol ORO5 tablets duma[ t~art rate rm-aired mSrfilicantiylowered on the Iirst day posttrea~nent. No rebound effect was ola~ewe~ "[here was slight diffenmcea in kinon~ of negative chronotropic effects between the 2 forrmlations measured ruder basal corflit~ortswhich are not reIlectmg nkaxroJn beta adrenc~eptor blockade. C h a i r e de Pharmacologie E x p l o r a t i o n s f o n c t i o n n e l les cfirCbrale et respiratoire - C.H.R. 25030 BESANCON CEDEX FRANCE

Department of Clinical Pharmacology and Therapeutics, Austin Hospital, Heidelberg, Victoria, 3084, Australia.

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DOUBLE-BLIND C L I N I C A L TRIAL C E L I P R O L O L VS. ATENOLOL IN MODERATE H Y P E R T E N S I O N J. Honorato, J.R. Azanza, M. C a t a l a n and J.R. Suarez In order to compare the e f f i c a c y and tolerance of Cellprolol in h y p e r t e n s i o n (I-II), we design B linear, doubleblind, randomized and c o n t r o l l e d clinical trial in which the control group was treated with Atenolol. The criteria for inclusion were: age included b e t w e e n 21 and 70 years old, male sex or sterile female Or submitted to contraception and signing of the informed consent, The criteria for e x c l u s i o n were: heart failure and a n y other organic or psychical pathology and the use of cortlcosterolds and IMAO, sympathomimetic, etc. The study was done in 4 phases (stages): a wash-out p e r i o d (2 weeks), dose fitting p e r i o d ( 6 weeks) in which the d o s e could be doubled if the initial dose turned out to be ineffective, maintenance period (6 weeks) and a p e r i o d of suspension of the a d m i n i s t r a t i o n of tbe active m e d i c a t i o n (2 weeks). In every c o n s u l t a t i o n the c a r d i a c frequency is controlled (60 sg.) a s wel~ as supine and s t a n d i n g b l o o d pressure. Twelve (60%) from the 20 patients treated with C e l i p r o l o l were men and 8 (40%) were women, the average related to the age was 48.9 + 8.3 (26 - 64) years old and their weight 82.7 Z 17.3 (56 - 113) Kg. In the group treated with A t e n o l o l 17 from the 20 p a t i e n t s were women (85%) and 3 were men (15%), their age was 55.35 + 6.12 148 - 72) years old and 70.2 + 12.8 (52 - 95) Kg. The initial dose Of Atenolol was 50 m E / d a y and of C e l i p r o io1 200 mE/day. (O.D.) The active treatment of anyone with of both drugs implied a significant decrease in the d l a s t o l i c b l o o d p r e s s u r e (10-12% of reduction), and systolic blood pressure (10%) and cardiac frequency, returning t o normal in 65% of the patients treated with the initial dose. Of the cases 14.39 were refractory to that dose a n s w e r e d at 400 mg of C e l i prolol and 42.9 at 100 mg of Atenolol. The intergroup differences were not significant except for the cardiac frequency during the active treatment, in which Celiprolol showed a much lower effect (7% of r e d u c tion related s the basal) than A t e n o l o l (179) ( p ~ O , O O l ) . A quarter of the treated p a t i e n t s ocassionally had cephalalgia in both groups. C o n s t i p a t i o n was d e s c r i b e d in the group treated with C e l i p r o l o l and a case Of c o n s t i p a tion, another of maleolar edema and a third of s o m n o l e n c e among the patients treated with Atenolol. Conclusion: C e i i p r o l o l is a drug as e f f e c t i v e as A t e n o l o l in the treatment of mild and m o d e r a t e h y ~ r t e n s i o n and equally well tolerated. It is b e c a u s e of this that Celiprolol could be the b e t a - b l o c k e r of choice s p e c i a l l y in cases which deal with m y o c a r d i c or b r o n c h o pulmonary pathology. Clinical P~armacology Service, Universltary Clinic of Navarra, University of Navarra, Pie XII s/n, 31080 Pamplona, Spain.

NON INVAS1VE SYSTEMIC AND REGIONAL HEMODYNAMICS OF BISOPROLOL AND ATENOLOL IN HEALTHY SUBJECTS. C. Thuillez) 3.P. Leroy, E. Pussard and 3.F. Giudicelli. Acute adr~nistration el beta-blocking drugs has been g~own to decrease cardiac aN~ut (03) and to increase syst~nic vasoAar resistar~ (SVR). The goals of the present study were to ~ in healthy volunteers the effects of two doses of blscprolol [10 (BIO) or 20 (B2O) mg], a new highly selective beta l-blod
These results indicate that, in oonlrast

to wowanolol (/k Simon et al., Prr~ 1 Cardiol., 537781, 198t~; C. Thuillez et al., Arch. Mal. Ceetr, in press, 867_, 1989), cardicr:elective beta-blocking 9 ugs 40 afford a relative protection of peripheral flows, this effect being wore marked in the carotidthan in the forearm vasoAar bed. Service de P h a r m a c o l o g i e Clinique, HSpital de BicStre, 78, rue du G~n~ral Leclerc, 9@275 - Le K r e m l i n - B i c ~ t r e C~dex, France.

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PHARMACOKINETICS AND fl-ADRENERG1C ANTAGONIST ACTIVITY OF BISOPROLOL AT REST AND DURING EXERCISE IN NORMAL VOLUNTEERS. F. Le Coz. P. Sauleman, B. Lecocq, M. Midavaine, J.-M. Poirier, C. Funck-Brenta.no, P. Jaillon. Exercise has been shown to alter the disposition of several fl-adrenoceptor antagonists. The consequences of this exercise effect remain uncertain but may well be of clinical relevance since a relationship between plasma concentrations of certain fl-blockers and their effects has been occasionally shown. We therefore investigated the influence of exercise on the pharmacokinetics and fl-blocking activity of the new fl-blocker bisoprolol (Bi). Eight normal volunteers received a single oral 20mg dose of Bi on two occasions, one week apart, in a randomized crossover study. Once they remained at rest and once they underwent repeated exercise tests 0.45h before (control) and 2.5, 5, 10, and 24h after Bi. Exercise (75% maximum workload) was performed on a cycloergometer. Pharmacokinetics of Bi were compared at rest and during exercise. Supine resting heart rate (HR) was measured every hour on both resting and exercise st.dy day. HR measured within lh following exercise were excluded. Average HR during 12h was determined from the AUC of effect. Exercise significantly decreased Bi AUC 0 ~ from 993• to 919• ng/ml/h (P<0.05) but did not alter Bi renal clearance (2.5:~0.7 vs. 2.5• ml/min~g), T89 (9.5• vs. 9.3• Cmax (86• vs. 90• ng/ml). The small but significant decrease in Bi AUC during exercise was associated with an increase in average resting HR over 12h from 56.2• to 60.7a:5.8 bpm (P<0.02). Bi significantly decreased maximum exercise HR from 136• to 105• at 2.5h, 106• at 5h, 109• at 10h and ll3• at 24h (all P<0.05). Conclusion: 1) Exercise increases Bi clearance or decreases Bi bioavailability, 2) This pharmacokinetic interaction is associated with a reduction of Bi effects on resting HR, 3) The /3-blocking activity of Bi following a single dose lasts at least 24h. Unit6 de Pharmacologic Clinique, H6pital Saint-Antoine, 184 rue du Faubourg Saint-Antoine, 75012, Paris, FRANCE.

THE EFFECTS OF LCNG-T~M BUNITROL(L THERAPY ON GLUCOSE METABCLISM IN PATIJR~TS WITH ESSENTIAL HYPERTENSION: A MULTICLINIC S%~3DY E. Gotoh, H. Shionoiri, T. Matsukawa, T. Arita, Y. Shioya and Bunitrolol Study Group ~he long-term antihypertensive response to bunitrolol (20-30 rag/day) and 75 g oral glucose tolerance following 6-month period of bunitrolol administration was evaluated in 30 patients with essential hypertension. Twenty-one of these 30 patients exhibited impaired glucose tolerance (IGT), while the remaining nine patients had normal glucose tolerance (NGT). All patients tolerated long-term bunitrolol therapy with no untoward effects except vision blurred, rash and pruritus for one patient. The bunitrolol therapy significantly decreased blood pressure in patients with NGT from 166+5/96+1 rmtHg (mean-+SE) to 148+5/88+i mmHg, and fran 171+4/98+2 mmHg to 166-+3/99_+3 nmHg in patients with IGT. Heart rate decreased significantly from 76 bpm to 63 bpm in NGT. On the other hand, it did not change in IGT. No patient with NGT developed diabetes mellitus. Neither fasting nor post-glucose-load venous blood glucose deteriorated in both groups during the therapy. There were no significant changes in the insulinogenic index (AIRI/~BS at 30 minutes after glucose load) in both groups. In patients with IGT, the concentration of glycosylated hemoglobin ( ~ Ar and Hb Ar did not change significantly from 9.4+0.6% to 9.9+0.7% and frem 7.3-+0.4% to 7.7_+0.5% respectively after the bunitrolol therapy. Ser~n lipids (total cholesterol, triglyceride, LDL-C, and HDL-C) did not alter in both groups. These results suggest that in addition to its antihypertensive effects, long-term bunitrolol therapy does not compromise glucose metaboli~n in hypertensive patients. The 2nd Department of Internal Medicine, Yokohana City University, 3-46, Urafune-cho, Minami-ku, Yokohana, 232 JAPAN

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DIFFERENTIAL CHANGESIN CARDIAC~i" AND ~2-ADRENOCEPTORS IN DIFFERENT FORMSOF HEART FAILURE. S. Motomura~ M.C. Miche1~ M. Khamssi, H.-R. Zerkowski*) and O.-E.Brodde

EFFECT OF AMOSULALOL ON HEMODYNAMICS IN ESSENTIAL HYPERTENSION - COMPARISON WITH PROPRANOLOL AND PRAZOSIN T. Saito~ K. Yamamoto and Y. Ina~aki In the treatment of hypertension appropriate drugs should be chosen for each patient, considering the hemodynamic features of the patients and the effects of drugs on the patients' hymodynamics. In comparison with propranolol and prazosin, we evaluated the hemodynamic effects of amosulalol during long-term therapy in patients with essential hypertension. Amosulalol (40-60 mg/day), propranolol (30-90 mg/day) or prazosin (1.5-6 mg/day) were given orally for 3 months to 22 patients with mild or moderate essential hypertension. It was found that amosulalol increased cardiac output and decreased total peripheral resistance but had no effect on heart rate. Its B-blocking action may be important in this respect by suppressing reflex tachycardia, which is probably related to decreased total peripheral resistance. Propranolol decreased cardiac output, increased total peripheral resistance and decreased heart rate. Prazosin slightly increased cardiac output decreased total peripheral resistance and increased heart rate. The effect of amosulalol differed from that of propranolol, suggesting that decreased total peripheral resistance due to the selective ~l-hlocking action of the drug may be important in its overall effect on hemodynamics. In conclusion , the hemodynamic effects of amosulalol that were demonstrated suggest that it may be a more desirable drug than either propranolol or prazosin for antihypertensive therapy in the aspect of hemodynamies. The third department of Internal Medicine, Chiba University, School of Medicine, 1-8-1, Inohana, Chiba City, Chiba 280, Japan

Evidence is rapidly accumulating that in heart failure cardiac ~-adrenoceptors (AR) are down-regulated presumably by increased catecholamines due to an { r e f l e c t o r i l y ) enhanced sympathetic a c t i v i t y . Since human heart contains both ~1and ~9-AR we studied changes in both ~-AR subtypes in d l f f-e-~ent kinds of heart failure. Total ~-AR density was decreased in right atria and right and l e f t ventricles from patients with end-stage idiopathic dilated and ischemic cardiomyopathy (NYHA functional class 1V) and in patients with Fallot's tetralogy. Moreover, in patients with mitral or aortic valve disease and varying degrees of heart f a i l ure (NYHA class II to class IV) right a t r i a l and l e f t vent r i c u l a r B-AR densities gradually declined in relation to the degree of heart failure. Assessment of ~ - and ~9-AR densities revealed, that in idiopathic dilated cardibmyopathy and aortic valve disease the ~-AR decrease is predominantly due to a decrease in ~I-AR density, whereas ~2-AR density is only marginally affetted; on the other hand, in ischemic cardiomyopathy, Fallot's tetralogy and mitral valve disease i t is caused by a concomitant decrease in ~land 89-AR density. Concomitantly with ~-AR density contr-" ~il~ responses of isolated e l e c t r i c a l l y driven right a t r i a and l e f t papillary muscles to isoprenaline were reduced, and this was related to the degree of heart failure, too. These data suggest that in different kinds of heart failure cardiac ~i- and 82-AR function is changed in a d i f ferential manner;'however, a common phenomenonfor a11 kinds of heart failure seems to be a down-regulation of cardiac ~-AR that might contribute to the progression of the disease. Supported by the SANDOZ-Stiftung f. Therapeut. Forschung and the Deutsche Forschungsgemeinschaft. Med.Klinik & P o l i k l i n i k , Abt. Nieren- & Hochdruckkranke and *) Abt. Thorax- & Kardiovasku1~re Chirurgie, Universit6tsklinikum Essen, Hufelandstr. 55, D-4300 Essen, FRG

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SODIUM INTAKE MODDIATES S~SITIVITY TO BETA RECEPTOR MEDIATED VASODIIATION DI~VJ~NTLY IN HYPERI~SIVES AND NOI~q~SIVES T. Naslund, D.J. Silberstein, W.J. Merrell, J.H. Nadeau and A.J.J. wood To determine the contribution of altered beta receptor function in the vasculature to the increased peripheral vascular resistance seen in hypertension the effects of intra-arterial infusions of isoproterenol (ISO) and epinephrine (EPI) on forearm blood flow were determined in ii male normotensives (NBP) and ii male hypertensives (HBP) during I0 and 250 m~ol/day Na diets. In the HBP sensitivity to ISO decreased on 250 n3~ol diet causing an increase from 43+_7 to 90_+21 ng/min (p<0.05) in the dose of ISO required to produce 50% of ISO increase in blood flow (ED50). In contrast, in the NBP increased Na intake resulted in an increased sensitivity to ISO induced vasodilation (ED50 decreased from 60+-13 to 32+5 ng/min, p
PHARFt~CODYNAMICSAND TOLERABILITY OF ULFS 49, A NEW SPECIFIC BRADYCARDICAGENT. D. N. D_uong1~ J.H.G. Jonkman2,~.B.M. Zuiderwijk2~ R.G.L. van Tel j and P.J.G, Corne]issen . The dose-response relation of ULFS 49, an agent which pharmacologically reduces heart rate (HR) without impairing c o n t r a c t i l i t y and coronary perfusion, was assessed in healthy male volunteers regarding pharmacodynamics and t o l e r a b i l i t y . ULFS 49 was administered by infusion (20 min.) in increasing doses (1,2,5,10 and 15 mg) as a single dose. The doses were divided over 5 treatment groups, each consisting of 4 volunteers. Of each group I subject received placebo and 3 subjects received ULFS 49 in a randomised double-blind design. The effect on HR and blood pressure was measured in resting condition as well as during exercise (bicycle ergometry). During all dose regimens no marked influence on blood pressure related to ULFS 49 was observed. No marked influence on HR occurred in resting condition as well as during exercise following infusion of ] mg and 2 mg compared to placebo. However, following infusion of 5, 10 and 15 mg ULFS 49 a pronounced reduction of HR was found both at rest and during exercise. Heart rate reduction compared to pre-drug values at rest, 60 min after start infusion Placebo 5 mg 10 mg 15 mg -8.4% - 1 1 . 1 % - 2 1 . 7 % -30.1% during exercise, 3 hrs after start infusion Placebo 5 mg i0 mg 15 mg +3.9% - 9.7% -23% -21.5% 10 hrs post-dosing there was s t i l l a HR reduction during exercise of about -14% in the 10 and 15 mg groups. The t o l e r a b l l i t y of all doses of ULFS 49 was good. ECG monioring and recordings, laboratory t ~ t s remained normal. Dr.Karl Thomae GmbH,Biberach (D), LPharma Bio-Research, Assen (NL), 3Boehringer Ingelheim, Alkmaar (NL).

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LONG-TERM EFFECT OF BOPINDOLOL ON SUPINE AND UPRIGHT RENAL FUNCTIONS IN PATIENTS WITH ESSENTIAL HYPERTENSION E. MIYAJIMA, Y. YAMADA, K. SUGIYAMA, T. MIYAKAWA, Y. TOKITA, H. SHIONOIRI, 0. TOCHIKUB0 and M. ISHII

R E C E N T D E V E L O P M E N T S OF T H E W H O I N T E R N A T I O N A L DRUG MONITORING PROGRAM INTENSIFIED SIGNAL ANALYSIS AND WIDER ACCESS TO DATA C. B i r i e l l , M. L i n d q u i s t

To investigate the long-term effect of a new long acting beta-blockade, bopindolol (BOP) on renal function in ~upine and upright postures, glomerular filtration rate (GFR), renal plasma flow (RPF), renal vascular resistance (RVR), plasma renin activity (PRA), plasma aldosterone concentration (PAC), plasma catecholamine concentrations (PCA) and plasma atrial natriuretic peptide (HANP) were measured in ! 1 patients with essential hypertension (av. age: 52•
The W H O I n t e r n a t i o n a l D r u g M o n i t o r i n g P r o g r a m a n d its C o l l a b o r a t i n g C e n t r e in U p p s a l a h a v e d u r i n g the p a s t 20 y e a r s a c c u m u l a t e d a d a t a b a s e of 600 000 a d v e r s e r e a c t i o n r e p o r t s and a w i d e e x p e r i e n c e in a d v e r s e r e a c t i o n m o n i t o r i n g and signal generation. In 1986 a n e w p r o j e c t was l a u n c h e d in o r d e r to i m p r o v e the e f f i c i e n c y of the W H O P r o g r a m to identify new adverse reaction signals. A panel of r e v i e w e r s f r o m p a r t i c i p a t i n g n a t i o n a l d r u g m o n i t o r i n g c e n t r e s four t i m e s a y e a r c h e c k the r e p o r t e d m a t e r i a l for n e w A D R s i g n a l s . D u r i n g o n e year, J u l y 87 - J u n e 88, c o m m e n t s o n 71 n e w p o t e n t i a l s i g n a l s w e r e c i r c u l a t e d to N a t i o n a l C e n t r e s . S o m e of the m o s t i m p o r t a n t w i l l b e published. Confidentiality restrictions on the adverse r e a c t i o n m a t e r i a l h a v e i m p o s e d a v e r y low p r o file o n the W H O P r o g r a m . Its r e s u l t s h a v e b e e n k e p t w i t h i n the c i r c l e o f p a r t i c i p a t i n g c o u n t ries and have b e e n a l m o s t n o n - v i s i b l e to t h e m e d i c a l p r o f e s s i o n in g e n e r a l . At the 1988 a n n u a l m e e t i n g of r e p r e s e n t a t i v e s of N a t i o n a l Centres delegates agreed on a procedure by which it w o u l d be p o s s i b l e to r e s p o n d to any i n q u i r y for a d v e r s e r e a c t i o n d a t a f r o m the W H O Centre. A r e q u e s t w o u l d be c i r c u l a t e d to N a t i o n a l C e n t r e s i n v o l v e d and a r e s p o n s e b a s e d o n t h e i r c o m m e n t s w o u l d be g i v e n w i t h i n two m o n t h s . It is a n t i c i p a t e d t h a t this n e w p r o c e d u r e w i l l be i m p l e m e n t e d d u r i n g 1989, and t h a t this w i l l lead to a b e t t e r use o f t h e W H O d a t a base. W H O C o l l a b o r a t i n ~ C e n t r e for I n t e r n a t i o n a l D r u g M o n i t o r i n g , B o x 607, S-751 25 U p p s a l a , S w e d e n

GFR 2 (ml/min.l.73m ) R P F 2 RVR (ml/min.l.73m) (mmHg/ml/min.l.73m 2) bef6re after before after before after ..................~...............~ ...................... Supine 99• i15• 440• 507• 0.16• 0.13• Upright 72• 92• 271• 369• 0.26• 0.17• -3....................................................... p < 0.05 compared to pretreatment value. Deptartment of Internal Medicine Yokohama City University ~chool of Msdicine~ 3-46, Urafune-sho, Minami-ku, Yokohama 232, Japan

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BAYESIAN DIFFERENTIAL D I A G N O S I S OF SEVERE IDIOSYNCRATIC REACTIONS TO NEW DRUGS. K.L. Lanctbt, D.A. Lane, C.A. Naranjo Severe idiosyncratic adverse reactions are an important source of morbidity and mortality. For example, they are frequently responsible for the discontinuation of newly marketed drugs. The differential diagnosis of these adverse events is complex because there are often several possible drug and nondrug causes. We tested a Bayesian-based aid for the differential diagnosis of drug- versus nondrug-induced illnesses. The Bayesian Adverse Reaction Diagnostic Instrument (BARDI) takes into consideration both background (e.g. epidemiological data) and case information (e.g. time of onset) in calculating a p o s t e r i o r p r o b a b i l i t y (PsP) in favour of the drug versus other etiologies. We applied BARDI to two examples of severe reactions associated with new drugs: 1) 9 cases of Guillain-Barr~ Syndrome (GBS) associated with zimelciine (Z) : and 2) 9 cases of neutropenia (Np) occurring during the administration of mexiletine (MXL). BARDI indicated that the probabilities that the 9 cases of GBS were caused by Z were very high (range PsP = 0.97-0.99), whereas the probabilities that the 9 cases of Np were caused by MXL were low (range PsP=0.0001-0.2). In the latter series of cases the PsP were in favour of procainamide for 6 cases (range PsP=0.8-0.999), captopril for 2 cases (PsP=0.7 and 0.99) and cyclic Np in 1 case (PsP=0.92). These results suggest that BARDI discriminates between drug-induced and nondrug- induced adverse events and can be applied in similar situations of severe idiosyncratic reactions to new drugs. Clinical Pharmacology Program, Addiction Research Foundation, and Departments of Pharmacology and Medicine, University of Toronto, 33 Russell St., Toronto, Ontario M5S 2S1, Canada

REQUIREMENTS FOR AN INTEGRATEDDATA-BASESYSTEM FOR THE EVALUATION OF ADVERSEDRUGREACTIONSAND FIRST EXPERIENCES WITH A NEW DATAMODEL (INMAST) H. Nowak, E. Ulbrich During international r e g i s t r a t i o n processes i t is necessary to keep ADR evaluation updated based on the state of international c l i n i c a l experience with the investigational compound. The large number of data and t h e i r inhomogenicity as well as the v a r i e t y of d i f f e r e n t strategies of analyses require adequate data processing and management. Computerized data-base systems seem to be an appropriate tool for this objective. As there are many subjects within one t r i a l and as different ADRs might be observed by just one subject, "relational data-base systems" (RDBS) are required. Following detailed system analysis which has to cover various legal obligations as well as scientific purposes, programs are established which have to be modular and f l e x i b l e . Ruies are defined for reducing the v a r i e t y amongst the individual reports on ADRs for the sake of a r a t i o n a l , transparent and managable standard. Thus, a hierarchical coding system should be integrated in the RDBS. Based on this experiences and according to the above requirements we have established a new data model called INMAST (Information Management~stem for _Trials). This is explained and our so far experience is outlined by examples. ASTA Pharma Aktiengesellschaft, D-6000 Frankfurt i , West Germany

Weism~llerstrasse 45,

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E L E C T R O N I C B I B L I O G R A P H I C DATA BASES : H E L P F U L FOR R E V I E W I N G A D V E R S E DRUG R E A C T I O N S ? THE ASPIRIN EXAMPLE

HOWTO EVALUATETHE SZDEoEFFECT PROFILE OF A DEVELOPNENTAL DRUGBASEDON STUDY MONITORINGAND CRFs E. Ulbrich, H. Nowak The information given in CRFs (demonstrated by examples) is very frequently unclear, misleading or even contradictory. GCP techniques are explained how to overcome inconsistent reporting. Advantages and problems of certain techniques developped to sort out the variety of safety items are described (e. g. WHO preferred terms). The necessity of these instruments for a proper evaluation of definable ADRs is shown, also explaining that this procedure alone might simplify information. Examples w i l l be given how misleading the definition of ADRs may be i f i t is based on these computed terms only (e. g. shock fragments attributed to various organ classes could be taken as independent symptoms). Careful examination of the correlation of symptoms one to each other potentially forming syndrom is most important. I t w i l l be concluded that biometric techniques are the only appropriate instrument in the managementof large safety data. Stratification by subgroups of patients defined e. g. by age, sex, comedication (with respect to interactions) and underlying diseases can thus be achieved. Transaminases are used as an example how important i t is to define borderlines of c l i n i c a l l y relevant changes of laboratory values. However, for most of the parameters, apart from trent analysis, no such reliable tool exists. The important difference between "adverse events" and "adverse experiences" w i l l be outlined and techniques for a proper d e f i n i t i o n are shown (biometric strategies for items without objective symptoms, e. g. "tiredness", casuistic evaluation of important reports and validation vs. placebo). ASTA Pharma Aktiengesellschaft, Weism~llerstrasse 45, D-6000 Frankfurt i , West Germany

F. H A R A M B U R U 1, J. E L M A L E M 2, J.C. PE RE1, B. BEGAUDI~ A.CASTOT 3 P. CARLIER 3, J. CARON 4. R.J. ROYER 5 Literature search are of major interest in all fields of medecine. We present a computer-based literature search on aspirin-induced adverse effects. Three electronic data bases were used : MEDLINE, EMBASE, RINGDOC. W e focused on years 1985 and 1986. The key-words used were ASPIRIN + ADVERSE EFFECT or TOXICITY. All the papers were gathered and analysed according to the organs involved and the type of papers. Three hundred fifty six papers were collected. The number of papers for each organ is as follows : gastrointestinal 118 aspirin-induced asthma, allergy 76 liver (inc/uding Reye's syndrome) 46 blood, hemostasis 36

poisoning skin kidney miscellaneous

24 21 15 24

For gastrointestinal effects, the papers were : clinical studies (69), reviews (12), drug surveillance (11), epidemiological studies (10), case reports (9), miscellaneous (7). With such a literature search, some drawbacks are highlighted : inadequacy of keywords for some papers dealing more with efficacy than with tolerance, poorly documented congress abstracts etc. leading to notable wastage. 1 Cenlre de Pharmacovigilance - H6pital Pellegrin - F 33076 Bordeaux - Cedex 2 Laboratoire Hoechst - F 92080 Paris La D6fense - Cedex 3 Centre de Pharmacovigilance - Hfpital Fernand Widal - F 75010 Paris 4 Centre de Pharmacovigilance -F 59045 Lille 5 Centre de Pharmacovigilance - CHRU - F 54037 Nancy - Cedex

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ADHERENCE TO REPORTING GUIDELINES FOR ADVERSE DRUG REACTION REPORTS MADE TO A REGIONAL MONITORING CENTRE F.M.Hickey,K.Oriffiths,P.Magee and L.Beeley The West Midlands Centre for Adverse Drug Reaction Reporting has been operating since 1981 as a regional monitoring centre processing yellow card reports for the UK Committee on Safety of Medicines (CSM). The region has a population of 5.2 million and the ~,400 hospital doctors, 2,800 general practitioners and 700 community health medical staff are encouraged to send ADR reports direct to the centre. A regular bulletin which lists ADRs received is distributed to reporting doctors. In this feedback the centre analyses the reports received in terms of suspected causality and whether or not the reaction is established for a particular drug or class of drugs. This assessment is dependent upon the completeness and quality of reporting. The regional bulletin and the CSM Current P r o b l e m s newsletters encourage doctors to report all suspected ADRs to new drugs (marked with a ~ in the British National Formulary and the Monthly Index of Medical Specialities) and unusual and severe reactions to older drugs. Reports from hospital and general practice doctors in the years 1981 to 1988 were separately evaluated and compared regarding: (I) the extent to which reports contained sufficient information to assess causality, (2) the proportion of reports which concerned ~ drugs, and (3) the proportion of reports which concerned unusual and/or serious reactions. The data presented give some indication of the effectiveness of CSM guidelines. Drug and Therapeutics Unit, Wolfson Building, Queen Elizabeth Medical Centre, Birmingham B15 2TH, United Kingdom.

IMPACT OF FEE ON REPORTINGOF ADVERSEDRUG REACTIONS J. Feely and P. O'Connor Spontaneous reporting of adverse drug reactions (ADR) through the yellow card system is grossly under u t i l i s e d . Only 20-35 ADR for 15,000 admissions were recorded annually in our hospital. We circularised prescribers with guidelines on what to report to a designated doctor and offered a small (s reporting fee. Within 6 weeks 150 ADR were received and these included 2 deaths (pentamidine associated pancreatitis and anaphylaxis with thrombolytic therapy). There were 32 serious or l i f e threatening ADR (including bone marrow suppression, gastrointestinal haemorrhage, arrhythmias, jaundice, Stevens-dohnson syndrome, warfarin interactions and pseudo-membranous c o l i t i s ) . T h i r t y additional ADR were received in the 6 weeks following termination of fee incentive and subsequently reporting declined steadily, The majority of prescribers were reporting for the f i r s t time and indicated ' f o r g e t t i n g ' , u n a v a i ! a b i l i t y of yellow cards and lack of f a m i l i a r i t y with the reporting system as the major constraints in reporting AOR. The majority (80%) indicated that the small fee provided an additional incentive. This study confirms that many including serious ADR go unreported. A small fee resulted in 6 weeks in a number of reports equivalent to that of the previous 6 years' spontaneous reports. Furthermore i t introduced many prescribers to the reporting system and preliminary evidence suggests that some of these doctors have continued to report ADR in the absence of a fee. This scheme is worthy of longer term evaluation. Department of Pharmacology and Therapeutics, T r i n i t y College Medical School, St James's Hospital, Dublin 8, Ireland.

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E F F I C A C Y OF SPONTANEOUS R E P O R T I N G F R O M AN A L E R T I N G P O I N T OF V I E W

THE INCIDENCE OF A D V E R S E DRUG REACTIONS (ADRS) DUE TO H z - B L O C K E R S IDENTIFIED BY AN INTENSIVE DRUG M O N I T O R I N G SYSTEM.

P. TUBERT*, B. BEGAUD**, J.C. PERE**, J.LELOUCH*, F. HA1L~MBURU** In drug surveillance, spontaneous reporting is the most efficient way for picking up new associations between a drug and a disease. For a given risk and a given area, the probability for detecting new associations is depending on : - the reporting ratio : MU - the relative risk in exposed patients : RR the number of exposed patients : NP the background incidence of the reaction in the general population : I

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The null hypothesis is that observed associations between a given drug and an adverse event are due to chance. Rejection, with a given risk, of this null hypothesis leads to an alert. Using the exact Fisher test it is possible to calculate, for given values of MU, RR, NP and I, the probability P for rejecting the null hypothesis. We calculated P for 144 different situations. For instance, with 15000 cases of the disease in the general population and, during the same period, 15000 patients exposed to the drug and a relative risk of 3.5, P=I for a reporting fraction of 0.5, P= 0.25 for a reporting fraction of 0.3 and P= 0 for a reporting fraction of 0.25. With 15000 case and 3000 exposed patients, P values are respectively : 0.95, 0.05 and 0. So in many cases, on the basis of spontaneous reports, it is not possible to confkm the relationship between a drug and a disease, except if the relative risk is extremely high. *

INSERM U 169 - HOP1TAL PAUL BROUSSE - 16, Avenue Paul Vaillant Couturier - 94800 VILLEJUIF - FRANCE

**

Centre de Pharmacovigilance de BORDEAUX - AQUITAINE H6pital PELLEGRIN - Zone Nord Bat 1A 33076 BORDEAUX - CEDEX - FRANCE

An

Intensive Drug M o n i t o r i n g Study, based in U n i v e r s i t y of H e i d e l b e r g Medical C l i n i c , identified a total of 73 ADRS due to H2Blockers in the period 1980-1986. In 1980-1982, 12% of admissions received Cimetidine during their in patient stay and in 1983-1986, 25~ of admissions r e c e i v e d Ranitidine. The incidence rate for Cimetidine was 1.74% which was higher than that for Ranitidine - 0 . 2 7 % . When these ADRS were r e - e x a m i n e d using the patient's clinical notes; 16.4% (of the 73) were r e j e c t e d and 45.2% were classifiable as p o s s i b l e or probable. In the remaining 38.4~, it was not p o s s i b l e to judge whether the ADR was due to the H2-Blocker or not. There is a significant difference b e t w e e n the ADR incidence rates identified by the o r i g i n a l documentation system (Cimetidine 1.74~, Ranitidine 0.27%) and those identified d u r i n g the re-examination (1.48~ and 0.22% the

respectiveley). H2-Blockers are amongst the most commonly p r e s c r i b e d hospital drugs, ADRS occur only very se!domly with rates of 1.42~ for c i m e t i d i n e a n d 0.22% for Ranitidine. Tamara J a c u b e i t , Div. Clin. Pharmacol. Univ., Bergheimer Str. 58, D-6900 Heidelberg, FRG While

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PP 04.10 A REVIEW OF SEVERE (ADRS) IDENTIFIED BY ADR REPERTING SYSTEM C L I N I C IN 1 9 8 8 .

ADVERSE DRUG REACTION~ AN INTENSIVE SPONTANEOUS IN A U N I V E R S I T Y MEDICAL

A bi-weekly visit is m a d e to e a c h ward in a University medical clinic (c.240 beds, 9.500 admissions/year) and ward doctors are asked to report any suspected ADRS. The clinical records of t h o s e p a t i e n t s reported to h a v e h a d an A D R are then examined in d e t a i l to e l u c i d a t e if a n ADR had actually occured. In 1 9 8 8 , 1 1 4 S e v e r e A D R S w e r e r e p o r t e d (a f u r t h e r 40 r e p o r t s w e r e r e j e c t e d ) . 90 of t h e s e i n volved only 1 drug, 23 i n v o l v e d 2 drugs and ! involved 3 drugs. The ADR was the reason for admission in 83 i n stances (73% of t o t a l ) , the remainder (31, 27%) occured during the inpatient stay. The drugs most frequently implicated were anticoagulants (44, 29%) %nd analgesics/antirheumatics (36, 24%). O t h e r c o m m o n l y implicated drugs were cardiovascular drugs (15, I0%) and antibiotics (II, 7 % ) . The commonest reported ADRS involved haemerrhage (48,. 42%) of w h i c h the m a j o r i t y involved t h e GI-tract (34). 1 previously unreported ADR (liver necrosis) was identified a n d 9 r a r e A D R s w e r e a l s o seen. Although the overall incidence of A D R S is l o w in comparison to total patient admissions (114:9.500), the systematic approach provides a clearer picture of t h e n o s a n d t y p e s of A D R s that occur in a h o s p i t a l than would be f o u n d via the normal spontaneous reporting systems. The study is supported by the Bundesgesundheitsamt. Dr. David Griffith, Div. Clin. Fharmacel. Univ., Bergheimer Str. 58, D - 6 9 0 0 Heidelberg, FRG.

EARLY DETECTION OF HEPATIC ADVERSE DRUG REACTIONS BY THE MEDICAL PRACTITIONER : MICROCOMPUTERISED BANK TO DIAGNOSIS A.ESCOUSSE*, C.SGRO*, M:BIOUR**, J.C. REGIN*, V.RIGOULOT* The early detection and monitoring of adverse drug rea~ions (ADR) by the medical practitioner is one of the most efficient methods to increase an knowledge of drug toxicity and prevent this toxicity. However, the most recent toxicological information on new drug is largely inavailable to the general practitioner for differential diagnosis of iatrogenic disease. Many possible ADR therefore remain unrecognized and unreported. This is the reason we tried to build a micro-computer (PC compatible) based expert system to help medical practitioner reach the diagnosis of iatrogenic disease and inform the physician how such a diagnosis is reached. We chose drug-induced hepatic disorders as the first target of this expert system, because there exist a consensus on the diagnosis of these disorders. The software consisted of two interactive modules : 1) The expert system : because of the lack of validated data on the epidemiology of drug-induced hepatic disorders, the system was based on "inexact reasoning", using the "min" algorithm : elimination of the most improbable diagnosis for the clinical (or biological) signs chosen, each with its specific weighing. 2) An interactive databank, H@petox (1) a computerised databank of published hepatic drug side effects containing specific information of the 641 drugs in the bank : chemical and pharmacological families, clinical and biological characteristics of toxicity, epidemiological data on hepatic ADR, number of publications, the databank is updated monthly. To detect the possible ADR, the physiean imputs the clinical and biological data, the names of the patients durgs. The interaction between the expert system and the databank then gives the probability of iatrogenic disease and the causality assessment of the drugs. This microcomputer-based system has been validated by comparing its conclusions with those of medical experts, on large numbers of established drug-induced hepatic disorders. (1) BIOUR M. etal H@patoxicit@ des m@dicaments. Mise & jour du fichier biobliogmphique des atteintes h@patiques et des m(}dieaments responsables. Gastroent@rol. Clin. Biol., 1988 ; 12 : 48-60 * Pharmacol.Clin., C.H.U. Dijon **PharmacoI.Clin., C.H.U. Paris St-Antoine

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ADVERS DRUG REACTIONS BY GENERAL PRACTITIONERS, INCIDENCE AND STATISTICAL RELIABILITY D. D r i s c h , D. G r i f f i t h , T. J a c u b e i t From the "Intensive Spontaneous Adverse Drug Reactions (ADR) M o n i t o r i n g System for General Practitioners", a study was undertaken in 1 9 8 8 to c a l c u l a t e the ADR incidence by using the reported A D R ' s in c o m p a r i s o n to the n u m b e r s of drugs prescribed. T h e p u r p o s e of t h e s t u d y w a s to i d e n t i f y the p r o p o r t i o n of ' c o m m o n ' A D R ' s that were actually reported. T h e i st s o u r c e of d a t a w a s a s t u d y in 1 9 8 4 of G e n e r a l P r a c t i t i o n e r s ' presribing habits. T h i s s h o w e d t h a t D o c t o r s w r o t e , on a v e r a g e , 18000 prescriptions per year and that the prop o r t i o n of t o t a l p r e s c r i p t i o n s t h a t w i l l be accounted f o r an i n d i v i d u a l d r u g c a n be p r e d i c ted within known statistical limits (+/- 25 %) as l o n g as the d r u g a c c o u n t s for at l e a s t 0.4 % of t o t a l p r e s c r i p t i o n s a n d t h a t at l e a s t 20 doctors are included in t h e s t u d y . T h e 2 nd s o u r c e of d a t a w a s all t h e A D R ' s r e g i s t r a t e d f r o m 1 9 8 2 - 87 b y G e n e r a l P r a c t i t i o n e r s reporting at l e a s t i0 A D R ' s . T h e s e 62 d o c t o r s r e p o r t e d 378 A D R ' s a s s o c i a t e d w i t h t h e m o s t 12 f r e q u e n t l y prescripted drugs ( n e a r l y i0 % of a l l p r e s c r i p t i o n s ) . The average reporting period was 1074 days. The average incidence was 0.117 % with some drugs being more commonly indicated (Adalat 0 . 3 5 %, V o l t a r e n 0 , 2 8 %) a n d s o m e m o r e r a r e l y (Adumbran, reported o n l y o n c e , 0 . 0 0 4 3 %). In c o n j u n c t i o n with the results from our and other clinic-based ADR systems, it s h o u l d b e possible to q u a n t i f y the a c c u r a c y of d o c t o r s ' reporting practices a n d to c a l c u l a t e the statistical reliability of t h e A D R - r e p o r t s themselves. T h e s t u d y is s u p p o r t e d by the "Bundesverband der Pharmazeutischen Industrie". Dominik Drisch, Div. Clin, Parmacol. Univ., Bergheimer Str. 58, D - 6 9 0 0 H e i d e l b e r g , FRG

DRUG M A N U F A ~ IN ADVERS~ DRUG REACTIONS (ADR) REPORTING B. Vrhovac and I. Frenceti6 Pharmaceutical industry (PI) is interested in ADR since they can cc~oromias the success and even cc~oletely "kill" I/heirproduct (new or old). Early identification of esp. severe ADR decreases drug-indsced diseases, save money end the image of its producer. All, esp. irmovative, firms have their own ADR services. A questioeneare has been sent to 27 comntries officially in the W~D ADR monitoring program. The results have been ccmpletsd by the published data. The majority - 9/11 ~8~/o) countries with high reporti~ rate (h.r.r.), i.e. 120 reports/lO inhab/year - r~spcnded. The analysis showed that The input of PI to the W~3 monitoring p r o ~ is surprisingly different in various countries. The percentage of reports received through thc PI varies between 0 and 90, the nordic countries and the USA being at the extremes. Cc~paring all h.r.r, countries, no cesmcn dencminater could be identified - attitude to the usefulness of PI reports, the impor'u~nce of feedback of the National centre (NC) to reporters, organisatien of tional m e e t ~ on ADR end inclusion of the reporting form into the prescription pads, even in the law enforcement of reporting bY6the PI. On the contrary, the countries with a lower input (2.4-120 rep/lO inhab) agree about the usefulness of the mentioned m e s s e s for reDortir~ stimulation. The majority of counthies are aware of the CIC~ activity in making the international data e x c ~ e less es~plex with a positive attitude. This study has identified a number of differences in otherwise similar coG~tries. All these and other informaticn collected indicate the need for regular analyses of various aspects of ADR monitoring with the aim of furthar improving the present situation. Th6 importance of manufacturers in ADR reporting depends on different conditions in various coustries. Of eot~se, the reports are everywhere orig~ted by the doctor who should ideally send his observations directly to the NC. National ADR centre, Section of Clin.Pharmacol., Dept. of ~dicine, University Hospital Rebro, Ki~oatideva 12, 41000 Zagreb, Yugoslavia

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DRUG MONITORING ~ R V I C E IN HUNGARY. Eggenhofer J.,Borvend~g J.,Gampe L.,Hank6 S. National Institute of Pharmacy,Budapest,P.B.450 National Institute of Pharmacy /N.I.P./ is responsible for monitoring and evaluating advers drug reactions /ADRs/ in Hungary. Reporting ADRs is not compulsory in this countr~ The munher of voluntary reports is 250-350/yea~ Three-quarters of cases are reported by hospital doctors, the rest by G.P.-s and pharmacists. The cause-effect relationship Can be classified as "definite" or "probable" in more than 50% of the cases. In a few cases/year quality problems are found to be responsible for the side effect~ The maiority of ADRs are firstly allergic, anaphylactiod reactions caused by i.v. X-ray contrast media, polydextran preparations, secondly hepatotoxic, haematological reactions indmced by hidrazin-derivatives, ~-methyldopa, pyricarbatum, steroids and cyanidanol. N.I.P. is responsible for giving information to the voluntary reporters in form of letters and if it is necessary to medical professionals as publacations, warnings, etc. It is also the d u ~ of N.I.P. to take other steps /e.g. withdrawing the incriminated preparation from the market as it happened in the case of Endocystobil and Catergen -, amending the package insert etc./ if required.

MODIFICATION OF THE KARCH-LASAGNA'S ALGORITHM FOR THE ASSESSMENT OF ADR IMPUTABILITY V Moreno, P Avila , M Ortiz, D Capell~ Several algorithms have been proposed to assess the imputability of drugs in adverse reactions. When compared, they show that a general concordance e x i s t s , but in each method the evaluation process gives each item a d i f f e r e n t weight. We have developed a modification of Karch-Lasagna's algorithm, which is generally used in the Spanish Drug Surveillance System. The structure of the algorithm has been modified in order to c o l l e c t , in a summarized way, as much information about the ADR as possible. Each item of Karch-Lasagna's algorithm has been modified to accept more subtle categories of the answer than the dual way of answering to the o r i g i n a l , and other items of i n t e r e s t have been added. The f i n a l c l a s s i f i c a t i o n in imputability categories is accomplished by counting a weight related to each answer, s i m i l a r l y to the method used by Kramer's or Narnajo's algorithms. The algorithm has been applied to the Spanish ADR database. About 4,000 spontaneous reports have been c l a s s i f i e d in the following categories: improbable (2%), conditional (8%~, possible (20%), probable (63%) and d e f i n i t e (7%). The comparison with the results obtained by other algorithms, as expected, shows great concordance. This concordance is greater with the original Karch-Lasagna's algorithm (k=0.69) but similar to the concordance with Kramer's (k=0.63) and Naranjo's (k=0.61). The concordance with the French algorithm is low (k=0.48). The i n t e r e s t in our proposed algorithm, besides the imputability assesssment -which is similar to that obtained with other ones- is the method of summarizing relevant information about the causal relationship between the drug and the adverse reaction through a systematic questionnaire. Servei de Farmacologia Clfnica. CS Vall d'Hebron. 08035 Barcelona.

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SIGNALS GENERATION IN A SPONTANEOUSADVERSE DRUGREACTION REPORTING SYSTEM (SADRRS) P Avila, b Capell~, V Moreno, M Ortiz, R Mendieta The characteristics of the Spanish drug market is f a r from r a t i o n a l : some 3,000 active principles in 13,000 preparations, of which approximately 55% are fixed dose combinations, the volume of information gathered in the SADRRS in Catalonia is about 4,000 reports, 124 per million inhab and year. However, the SADRRShas allowed f o r the discovery or improvement of ADR signals and p r o f i l e s , and f o r the generation of working hypotheses f o r epidemiological studies -the main objectives of the International WHO programme. The information on new drug-reaction associations in the database is p e r i o d i c a l l y reviewed and various ADR p r o f i l e s of drugs of the same pharmacological groups have been compared. Some relevant adverse effects of preparations of unproven effectiveness have been described: i) cinepazide, a cerebral and peripheral vasodilator, has been related with a high r i s k of agranulocytosis (93 per m i l l i o n prescriptions); 2) c i t i o l o n e , used as a mucolytic in Spain, but as a hepatoprotective agent in other countries, causes ageusia and hypoageusia; 3) bendazac, an NSAID used f o r the oral treatment of cataracts, is associated with the r i s k of hepatotoxicity; 4) cinnarizine and f l u n a r i z i n e , promoted as "cerebral vasodilators", can cause parkinsonism and depression. This system has also enabled the comparison of the risks of d i f f e r e n t unwanted e f f e c t s f o r preparations of the same therapeutic group: a greater risk of photosensitivity associated with demeclocycline, compared with the other tetracyclines; an excessive r i s k of extrapyramidal reactions by clebopride, compared with metoclopramide; or a similar r i s k of hepatotoxicity by the various erythromycin salts. These findings lay open the need to establish i n t e r n a t i o n a l l y co-ordinated drug surveillance systems. Servei de Farmacologia Clfnica. CS Vall D'Hebron. 08035 Barcelona.

ADVERSE DRUGREACTIONMONITORINGSYSTEMUSING DISEASE REGISTRATIONSYSTEM --Analysis of 9 years experience at a community hospital - R. Hama, K. Mori, M. Hashinotsume, H. Miura, Y. Okamoto, T. Arima, S. Murata and N. Hashimoto, H, Endo. Usefulness of the Adverse Drug Reaction(ADR) Monitoring System at our hospital was assessed. {Methods ] (i) System:an ADR case is registered as a diagnosis name. I t is written as "AR-rash-ampicillin" on a diagnosis name-sheet which is attached to a prescription sheet. ADR case l i s t s are generated periodically. Doctors and pharmacists make reports and f i l e them. Important ADRsare feed-backed to daily medical practices. (2) Early detected and supposed important ADRs are sometimes investigated by means of formal studies. [Results ] (~) 2197 ADR cases were filed during 9 years. (~) Affected organs/systems:skin;31%,GI;22%,CNS;9%,systemic;8% CausativeDrugs:cardiovascular;21%, CNS drugs including NSAIDs;21%, antibiotics;17%. Severe reactions ranked as category 1(WHO) :184 cases. (~) Formal studies: I)A survey carried out after experiencing a cotrimoxazol-induced pancytopenia revealed that frequency of blood disorder was twenty times higher or more than that reported previously in Japan. 2)Incidence of leukopenia and/or thrombocytopenia was s i g n i f i c a n t l y higher in cimetidine injection users than in non-users. 3)The increased incidence of post-transfusion h e p a t i t i s in 1980~81 was related to the over-production of component blood prodcts especially fresh-frozen-plasma and its use. 4)Incidence of anaphylactoid reaction to oral antibiotics were comparedafter experiencing four cases of cefaclor-induced anaphylaxis. ~ncidence f o r cefaclor was s i g n i f i c a n t l y higher than the others. [Conclusions ] (~)Although the system is base on a spontaneous reports, (~)readily writable system makes early reporting of important ADR cases (~)which are feed-backed to the usual medical practices. (~)Comparisonof frequency of a paticular ADR is available. (~)someformal studies conducted a f t e r reporting important ADRsoften revealed new facts. | contribute to the safe and rational use of drugs.

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A PROSPECTIVE STUDY OF ADVERSE DRUG REACTIONS IN AN INTERNAL MEDICINE DEPARTMENT. A. Due~as-Laita, J.C. Martin-Escudero and M. Pozuelo Clinical Pharmacology Research Group, A r e a o f Pharmacology, Faculty of Medicine, University of Valladolid and R~o Hortega Hospital, Valladolid, Spain. A one year pilot intensive drug surveillance program has been established on the Internal Medicine wards (102 beds) of the Rfo Hortega Hospital. This program uses methods modified from those developed by the Boston Collaborative Drug Surveillance Program. Data from 1079 (mean age 61.i~ 17.9, ~ ~ SD) in-patients (647 male and 432 female)monitored have been analysed. We detect 262 adverse drug reactions(ADRs)in 227 patients (21%), from those 24 (10.5%)had more than one ADR. In 29 patients (2.7% of the total population) the hospital admission was due to an ADR. During the study only one death was directly attributable to an ADR,which represents the 1.4% of the in-patients causes of mortality. The ADRs were considered severe in 26 (9.9%), moderade in 141(53.8%) and mild in 26 cases (36.2%). Gastrointestinal symptoms (vomiting, abdominalpain, etc.) were the most frequent ADR (33.9%), followed by central nervous system (21.8%), cardiovascular (11.0%), endocrino-metabolic (ii.0%)and cutaneous manifestations (8.4%). The most common drugs involved in ADRs were: insulin, digoxin, nitrates, diuretics, amoxycillin/clavulanic acid, cytotoxic drugs and corticosteroids. Patients without ADRs stayed in the hospital for an average of 12.3 ~ i0.9 days and the population suffering from ADRs 16.9 ~ 15.8 days (p
EVALUATION OF CYCLOSPORIN-A SIDE ~FECTS IN HEART TRANSPLANT RECIPIDITS: STABLE SYSTEMIC h~F~FENSION- SDOWLY PROGRESSING RN~A5 mSIFFI~

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STEVENS-JOHNSON AND LYELL SYNDROMESCOLLECTED BY A SPONTANEOUS REPORTING SYSTEM M O r t i z , D Capell&, V Moreno, P A v i l a , R Mendieta The skin is often affected by medication. Although most cutaneous adverse reactions are s l i g h t , some can be severe, such as Lyel] and Stevens-Johnson syndromes. iSince 1983, the Catalan Adverse Drug Reaction Reporting System has received around 4,000 reports of adverse r e a c t i o n s , of which 30% a f f e c t e d the skin and appendages. There have been i i cases of Stevens-Johnson (8 men and 3 women), with a mean age of 29 (6-60), the mean duration of the reaction was 6 days (5-42). They a l l recovered a f t e r medication was withdrawn, although two had sequels. The implicated drugs were a n t i b i o t i c s in 7 cases, an a n t i m a l a r i a l in one, anti-inflammatory analgesics in another ( i n c l u d i n g a fixed-dose combination of ascorbic acid, c a f f e i n e , chlorphenamine, codeine, paracetamol and s a l i c y l a m i d e ) , and an antigout in two. Seven cases of Lye]l syndrome have been reported (6 men and 1 woman) with a mean age of 63 (21-90), the mean duration of the reaction was 22 days (2-36). They a l l recovered when medication was withdrawn, except f o r one f a t a l case. The implicated drugs were a n t i b i o t i c s in 5 cases ( a z ] o c i l l i n , fosfomycin, cefonicid and c e f t a z i d i m e ) , a n t i e p i l e p t i c s in one, and a d i u r e t i c in another -with p o s i t i v e re-exposure. The age d i f f e r e n c e s and male predominance in both syndromes are worth noting. Despite the short number of cases, new associations between drugs and adverse events have been detected, such as Stevens-Johnson syndrome caused by the r e f e r r e d fixed-dose combination, and Lye]] Syndrome caused by a z l o c i l l i n , fosfomycin, cefonicid and ceftazidime. In a l l of them, however, the i n d i c a t i o n f o r the use o f these drugs ( f l u , pneumonia by pseudomonas or sepsis) could have been a confounding f a c t o r . Servei de Farmacologia C]fnica. C S Vail D'Hebron. 08035 Barcelona.

W yon Scheidt, U Zie~ler, A Remmel, R Uhl, BM Komkes*, g ~xhnann C!mlesporin-A (CYA) is known to induce systemic hypertension and impairmant of renal fenction. It is not clear, however, whether both side effects are progressing with time. This problem is test investigated in non-renal transplant recipients to exclude dlenges caused by transplant rejection or other renal problems. We investigated 45 heart transplent recipients by yearly cardiac catheterization over a period of up to 5.5 years. Creatinime-, snditm- and other biochemical values as well as CYA-levels were obtained simaltsnsously. Results: Interval since HTX mo. 12.2 23.8 37.2 49.1 68.0

n 36 23 14 ii 5

Aortic pressure CI aye dia mean I/ m~g mim.~

SYR CRs dyn-smr ~ ~7%

CYA Na§ dose lev. mol/ mg/d r ~ I

147 140 149 134 142

1492 1397 1453 1390 1375

350 349 355 289 280

90 92 92 86 87

112 113 115 105 iii

3.1 3.6* 3.4 2.9 3.1

1.68 1.89 2.00 1.80 2.10

95 82 90 99 87

141 142 141 141 141

*p 0.05 The dose of antihypertensive drugs (betablockers, Ca-antagnnists, ACEinhibitors and/or diuretics) or corticosteroids was not changed significantly during this time. Concltmien: Treated CYA induced systemic hypertension is characterized by a cardiac index (CI) and systemic vascmler resistance (SYR) in the upper normal range. Deterioration does not occur in a follow up of 5.5 years (stable relation of systemic hypartension/dosagn of antihypertensive &rugs). Moderate renal function impairment seems to progress very slowly. These investigations in heart transplanted patients show that CYA induced side effects (renal insufficiency, hypertension) may differ in their mechanism and severity from those in renal transplant recipients. Medizinische Klinik I und Herzchimtrgische Klinik*, K l ~ hedern, Universit~t M&nchan, D-B000 Mfmchen

6r~-

CONVERTING ENZYME INHIBITORS AND COUGH:A PREDICTABLE A D V E R S E REACTION? C. Kreft, X. Jeunemaitre, E. Billaud, C. Weber, P.F. Ploui n The a i m of the study was to assess the incidence of cough in a p o p u l a t i o n of patients treated with Captopril (C) or Enalapril (E) and to determine whether clinical features could enable the p r e d i c t o n of this adverse reaction. Between january 1980 and december 1987, 2310 hypertensive patients seen in one hypertension clinic received an a n g i o t e n s i n converting enzyme inhibitor: 34% received C and 66 % E. Cough was reported by 96 patients: 75 E, 21 C. The incidence of cough was 4.9 and 2.7 % (p<0.0l) respectively. Mean daily E dose was similar in patients w i t h or without cough (18+5 vs 19+5 mg) but was lower in patients under C in-whom cough d e v e l o p e d (76+31 vs 113+61 mg, p<0.01). Cough was independant of d o s e used and the d e l a y of repporting was e x t r e m e l y variable (5 days to 29 months). The following table describes the clinical features in b o t h groups: Cough Age Sex B.M.I. ~ P SBP Creatinine Smoking CAO Associated M% kg/m2 length rmnHg [mnol/l % Yes % No BB % Di~r. Yes NO

50 54

61 63

25 25

B.M.I.: ~cdy Mass Index }~P: High Blood Pressure

9 Ii

181 182

102 i00

20 13

97 95

21 24

58 56

CAO: Chronic Airways Obstruction BB: Beta-Blocker ; Diur.: Diuretic

NO significant statistical difference was seen among the clinical and biological features tested. No significant sex difference was shown. Previous smoking habits or chronic airways obstruction did not screen a high risk population. Symptoms were sufficiently disturbing to warrant withdrawl in 75% of patients. Service Pharmacologie Clinique, Service Hypertension Art~rielle. HOPITAL BROUSSAIS, 96, rue Didot, 75674 PARIS CEDEX 14.

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CARDIAC EVENTS UNDER CHEMOTHERAPYINCLUDING 5FU RETROSPECTIVE REPORTOF 24 CASES.

The

J.L REBISCHUNG, A. PONZIO, J.M VANNETZEL. Unit6 d'oncologie m~dicale-Hopital Saint Joseph-PARIS 14~

Muzolimine is a H e n l e ' s l o o p d i u r e t i c w i t h a rapid and long-lasting effect.This pyrazolon d e r i v a t e h a d to be r e m o v e d 2 y e a r s a f t e r official a d m i s s i o n in the F . R . G . b e c a u s e of n e u r o l o g i c a l side effects. We o b s e r v e d a s u b a c u t e s e v e r e n e u r o m y e l o p a t h y in, 7 patients with chronic renal failure. The c r i t i c a l d o s e of m u z o l i m i n e f o r f i r s t n e u r o l o g i c a l i m p a i r m e n t w a s 52g a f t e r an a v e r a g e t r e a t m e n t p e r i o d of 78 days. T h e p a t i e n t s p r e s e n t e d w i t h pallhypaesthesia, s p i n a l a t a x i a a n d s i g n s of peripheral neuropathy. W i t h i n in a f e w w e e k s a myelopathy w i t h p a r a - or t e t r a s p a s t i c paresis developed. Neuroradiologieal investigations and laboratory findings excluded known causes for the n e u r o m y e l o p a t h y . Neurophysiological measurements a n d p o s t m o r t e m f i n d i n g s in two cases demonstrated m a i n i n v o l v e m e n t o f the spinal posterior c o l u m n a n d the l a t e r a l corticospinal tract. No s i g n i f i c a n t r e c o v e r y w a s s e e n in a f o l l o w - u p p e r i o d of 2 y e a r s a f t e r interruption of m u z o l i m i n e - t h e r a p y . The most severe neurological deficits occurred in n o n - d i a l y t i c p a t i e n t s . As m u z o l i m i n e itself is m a i n l y m e t a b o l i z e d prerenally, a partially dialysable t o x i c m e t a b o l i t e of the d r u g h a s to be d i s c u s s e d f o r its n e u r o t o x i c i t y .

Among 143 patients treated by chemotherapy including 5FU by continuous infusion (600 mg/m2 d I-4) we detailed 24 concomitant cardiac events. I t was 4 females, 20 men, median age 57 y (42-79). All but one received 5FU with Vindesine or VP16, Cis Platyl and radiotherapy (11 on chest aera). Cardiac complications were symptomatic in 22 cases, with 7 ischemic chest pains (ICP), 3 p e r i c a r d i t i s (P), 14 rythmic disorders (RD) including 5 grade 4 with 4 t o x i c deaths, 10 grade 3, 2 grade 2 and 7 grade I . No dose-effect correlation can be etablished. Reintroduction in 14 cases was positive for 4 ICP despite n i t r a t e derivates or amiodarone, one P and 4 RD. A retrospective analysis of cardiac enzymes, metabolic perturbations, h o l t e r , bidimensional echography is presented and a strategy proposed for reintroduction of 5FU including cardiac story, t o x i c i t y grading.

P.

neurotoxicity Berlit,

of m u z o l i m i n e

B.Pohlmann-Eden,

N. G r e t ~

Neurologische und Nephrologische Klinikum Mann~eim , Universtit~t

Klinik, Heidelberg,F.R.G.

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ADVERSE DRUG REACTIONS REPORTING ON ORAL CONTRACEPTIVES

RISK OF SPONTANEOUS LIVERRUPTURE UNDER FIBRINOLYTIG THERAPY G. Piper, M. Hammerer, W. Remmele, H. v. E~idy Bleedings from the liver under fibrinolytis therapy (ft) of deep vein thrombosis are extremel V rare. Eight not by trauma or tumor sufficientl V explained cases of spontaneousl V rupturing livsrhematomas are reported (I-5): 2 men, 6 women, 2?-64-years-old, 4 women (as far reported) used oral contraceptives (ms). 3/5 histologies showed staatosis.Bleedings developed later than 48 hours of ft.7/8 patients received standard streptokinase,I/8 had one period ultra-high dose streptokinase (6), then standard-dose urokinsse.4/8 patients survived by immediate surgical treatment. We treated s 49-years-old woman with ultra-high-dose streptokinese because of pelvic vein thrombosis. No minor bleeding happened, Clotting parameters changed to fibrinolytic state. 4 hours after the 4th treatment period, in the 82nd hour the patient reported uncertain abdominal complaints and developed a foudroyant hypovolemic, letsl shock. Fluid masses were detected by ultrasound intraabdominally. Necropsy revealed a deep rupture of the right liver lobe without detectable source of bleeding. Histology: Up to 50 % Fatty liver degeneration~ minor to moderate hepatitis r no peliosis hepatis. The patient took oc over 8 years and conjugated estrogens during the last 9 months. Data hint to some risk factors: Risk arises an 3rd day of ft, seems to be higher in women (7/9) after pretreatment with oc or estrogens (5/7 women) and is related to stestosis hepatis (4/6 histologies). Observations support speculations (4, 5) about hormonally induced minor forms of peliosis as reason for intrahepatic vascular fragility. Only very early detection of intraperitoneal bleeding leaves s chance to successful emergency laparotomy. (I) EklBf et el., VASA 6,369-371, 1977, (2) Mriessmenn et el., Fortschr.Med. 95, 856-866, 1977, (3) Willis, Bailey, Arch.lntern. Med. 144, 2064-2085, 1984, (4) Pansold et el. Z.Brztl.Fortbildung 79, 575-576, 1985, (5) Habscheid, Brush, Intensivmed 25, 288-288, 1988, (6) Martin et el. Dtsch.med.Wschr. 108, 157-171, 1983. Medizinische Mlinik A und Institut for Pathologie, Hlinikum der Landeshauptstadt, 6200 Wiesbaden, F. R. Bermany

G. Hopf, B. M a t h i a s a n d C. Piper A p r e v i o u s s t u d y (C. Piper a n d B. Mathias, Med. Klinik, in press) reviewed a d v e r s e d r u g r e a c t i o n s (ADR) of oral c o n t r a c e p t i v e s w h i c h were r e p o r t e d to t h e D r u g C o m m i s s i o n of t h e G e r m a n Medical P r o f e s s i o n u n t i l 1986. We n o w m a d e a follow-up s t u d y of reports of 1987 a n d 1988 a n d c o m p a r e d it to the former study. In b o t h s t u d i e s a b o u t 4 0 % of t h e r e p o r t s were a t t r i b u t e d to w o m e n aged 15-30 years a n d 30 % to t h o s e aged 31 a n d over. 7 % (10 % in t h e earlier study) of all r e p o r t s were related to p r e p a r a t i o n s c o n t a i n i n g more t h a n 0.05 m g estrogen, 19 % (66 %) to t h o s e c o n t a i n i n g 0.05 m g a n d 74 % (24 %) to c o n t r a c e p t i v e s w h i c h c o n t a i n less t h a n 0.05 rag. Like betore, t h e r e were few r e p o r t s o n ADR c a u s e d b y p r o g e s t a g e n only preparations. The p e r c e n t a g e of r e p o r t e d d i s o r d e r s of m o s t o r g a n c l a s s e s were similar i n b o t h s t u d i e s (i.e. skin, n e r v o u s s y s t e m , liver a n d b i l i a r y s y s t e m , g a s t r o i n t e s t i n a l system). Only reports o n arterial a n d v e n o u s t h r o m b o s i s s h o w e d lower p e r c e n t a g e s , t h u s s u g g e s t i n g a positive correlation b e t w e e n lower c o n t e n t of e s t r o g e n a n d less r e p o r t s of ADR. No significant age-related effects could b e n o t i c e d , b e s i d e s l e s s I~eports o n r e p r o d u c t i v e d i s o r d e r s in older w o m e n a n d on b e n i g n n e o p l a s m s of t h e liver in y o u n g e r women. Arzneimittelkommission der deutschen ,~rzteschaft, Herbert-Lewin-StraJ3e 5, 5000 KSln 41, FRG

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MULTIPLE ASCENDING DOSE STUDY OF LOW MOLECULAR WEIGHT HEPARIN (CY216D) IN COMPARISON TO UNFRACTIONATEDHEPARIN IN NORMALVOLUNTEERS PT Leese, MD Freedman, R Prasad, D Hayden Unfractionated Heparin (UH) has been associated with significant elevation of serum transaminases. CY216D, a new low molecular weight heparin, MW=4500, was evaluated in two studies for safety, tolerance and pharmacokinetics. Study One involved 50 normal males randomly assigned to I of 5 single-blinded treatment groups. Each group, consisting of 8 Active ( 1 5 , 30, 45, 60 or 90 mg) and 2 Placebo participants, received 5 daily subcutaneous (SC) injections. All active group means for serum transaminases were significantly elevated in comparison to placebo by the last day of dosing (P<.01) and were generally higher 48 hours following the final dose. Study Two involved 18 normal males randomly assigned to I of 4 double-blinded treatment groups. TID SC injections for 14 days were administered as follows: Group I. Placebo TID, Group If. 5000u. UH TID, Group I l l . 30 mg CY2160 qd, Group IV. 60 mg CY216D qd. Group I had 3 subjects; Groups I I , I I I and IV had 5 subjects each. Subjects were also evaluated f o r a i0 day washout. In Groups I I and IV, ALTs were statistically significant in comparison to placebo by DOS 8. All group ALTs were decreased at DOS 12 ( a c t i v e period) and continued to decrease during the wash-out period; group I I I (30 mg CY216D) had no AST or ALT abnormalities. In summary, there is i n t e r - s u b j e c t v a r i a b i l i t y in the transaminase response to subcutaneousl y administered UH or CY216D. The d i f f e r e n t i a l diagnosis of t h i s phenomenon in patients so t r e a t e d should include a d i r e c t drug e f f e c t . We conclude that the g~ycosaminoglycans which produce hypertransaminasemia with UH are also present in t h i s LMWH. Quincy Research Center, 5104 East 24th Street, Kansas City, MO 64127

THE CLINICAL ANALYSIS OF MEPIVACAIN AND3BUPIVACAIN ACTION ON THE ELDERLY AND S E N I L E A G E PATIENTS AT THE CEREBROSPINAL A N A E S T H E S I A A.N.Agh%yan and R . G . B o r o y a n The action of mepivacazn and bupivscain, used for the subarachnoidal (SA) and peridural (PD) anaesthesia at the surgical operations was stud i e d on 272 patients at the age of 60-99.Anaesthesla was carried out on the occasion of general surgical,urological,traumotological and orthopedical operations. The catheteral PD anaesthesia in combination with n e u r o l e p t a n a l g e s i a was performed for some patients. All the patients had one or more concomitant ~iseases (diseases of c a r d i o - v a s c u l a r and r e s p i r a t d r y systems,diabetes mellitus and others). The results of investigations allowed to establish,that neither mepivacain (subarachnoidal adm i n i s t r a t i o n of 4% solution in dose of Img/kg), nor bupivacain (subarachnoidal or peridural adm i n i s t r a t i o n of 1-4ml 0,5% solution),which induced rather dup a n a e s t h e s i a , p r a c t i c a l l y had no influence on the systemic arterial p r e s s u r e , t h e respiratory system f u n c t i o n s , a c i d o - a l k a l i n e conditions and blood gases (pOo,pCOp),or on the ECG-indices.Moreover,the p o ~ t o p e P a t i v e mortality was comparatively low (3,6%) and was not in the direct connection with the way of anaesthesia,The changes of these indices at n e u r o l e p t a nalgesia were considerable and m o r t a l i t y in p o s t o p e r a t i v e period was higher (IO,5%).At comb i n B b i o n of n e u r o l e p t a n a l g e s i a and catheteral PD anaesthesia by the help of b u p i v a c a i n the complications of n e u r o l e p t a n a l g e s i a are minimized and the m o r t a l l t y dzdn t exceed 5,4%. Meisenweg 5 6588 B i r k e n f e l d / N a h e F.R.G. and Yerevan-25,Kirov str.2,Medical Institute, U.S.S.R. 375025

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HAEMOLYSIS IN STROKEPATIENTS RECEIVING GLYCEROL: IN VIVO AND IN VITRO STUDIES.

TRIAZOLAM-INDUCED BRAIN IMPAIRMENT: FREOUENT MEMORY DISTURBANCES E.O. Bixler, A. Kales, R.L. Manfredi and A.N. Vgontzas The effects of bedtime drug administration on daytime memory were evaluated in three groups of six subjects each (triazolam, 0.5 mg, temazepam, 30 mg, and placebo). A double-blind, parallel-group design was employed which used both within-and between-group placebo control. The 12 consecutive night sleep laboratory study included a placebo baseline followed by a varying schedule of five nights of active drug and three additional placebo nights. Assessment of drug use on immediate recall in the morning upon awakening indicated no difficulty for subjects in any of the three groups. However, during the day, five of the six triazolam subjects (83%) experienced a total of 12 episodes of memory difffculty, either anterograde memory impairment or frank amnesia. The rate of this triazolam-induced brain impairment was 40.0% (12 episodes per 30 subject days). For all five subjects this behavior was atypical and did not occur during either baseline or placebo periods. Because triazolam has an ultra-short half llfe, these effects cannot be attributed to daytime carryover of hypnotic effects. No such episodes were reported by any of the subjects in the Temazepam Group, while one subject in the Placebo Group reported an incident of daytime memory impairment during each of the three conditions. When recall of a word list presented in the morning was tested subsequently in the evening at bedtime, subjects taking triazolam remembered the least (N.S.). Further, their delayed evening recall of tasks performed in the morning was significantly impaired compared to the Placebo Group and close to three times more impaired than that of the Temazepam Group. Thus, daytime brain impairment induced by bedtime use of triazolam is shown to be a frequently occurring phenomenon. These severe impairments, combined with the fact that such side effects are unexpected and not easily attributed to the drug, may result in marked behavioral/emotional consequences for patients. Sleep Research & Treatment Center~ Milton S. Hershey Medical Center, Hershey~ Pennsylvania 17033

CR Kumana, GTC Chan, YL Yu, IJ Lauder, T Chan, M Kou Patients with acute strokes entering a double blind, randomised controlled t r i a l of therapy with intravenous glycerol, had the extent and pathogenesis of any ensuing haemolysis monitored / investigated using standard laboratory tests and i n - v i t r o techniques. 20 patients received 10% glycerol (500 ml over 4 hours) on 6 consecutive days and 15 received corresponding control treatment ( s a l i n e ) . A degree of glycerol induced intravascular haemolysis was evident after the f i r s t infusion; compared to the controls the treatment group had i) greater reductions in serum haptoglobin concentrations (p
In v i t r o studies revealed that primary exposure of blood to 1-10% glycerol (in saline) did not per se induce red blood cell (RBC) lysis. On RBC re-exposure to lower glycerol concentrations (secondary exposure), lysis ensued provided there was a minimum osmotic gradient between primary and secondary exposure.

Thus, RBC lysis probably ensues, only when venous blood acquiring high glycerol concentrations mixes with blood containing l i t t l e or no glycerol. The patients we studied did not have c l i n i c a l l y significant glycerol induced intravascular haemolysis. Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong.

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PP 04.30 HIGH PREVALENCE OF SIDE EFFECTS WITH TRIAZOLAM: AMNESIA, HYPEREXCITABILITY AND WITHDRAWAL DIFFICULTIES A. Kales, E.O. Bixler, R.L. Manfredi, A.N. Vgontzas, and J.D. Kales Recently, three separate European drug regulatory agencies (France, Italy, West Germany) removed the 0.5 mg dose of triazolam from the market citing highly undesirable side effects including amnesia, hyperexcltahillty states and withdrawal difficulties. However, such clinical reports and adverse drug reaction surveys, while useful, do not provide a true prevalence for the occurrence of side effects. To obtain a prevalence rate for certain side effects, we analyzed nine double blind and placebocontrolled studies previously conducted in our laboratory with triazolam, 0.5 mg; temazepam, 30mg; flurazepam, 30 mg; and placebo. In one 0.5 mg study of triazolam that assessed memory effects, we found five of six subjects (83%) had daytime episodes of memory impairment or anterograde amnesia with a total of 12 episodes following 30 drug nights(40Z rate for this type of acute brain impairment). In the other studies, we assessed the prevalence of hypere• states during drug administration (early morning insomnia) and withdrawal difficulties (rebound insomnia). A high proportion of triazolam subjects manifested hyperexcltability states (7 of 8 subjects, 88%) and withdrawal difficulties (6 of 8 subjects, 75%). Furthermore, the degree of early morning insomnia and rebound insomnia for triazolam ranged from three to five times that of temazepam, flurazepam and placebo. Thus, we demonstrate that a number of the serious side effects reported worldwide for triazolam occur in the majority of subjects taking the drug, an alarming prevalence rate. There are a number of reasons why these side effects are not reported this frequently in clinical practice: I) they are quite unexpected by the physician and patient and thus not easily attributed to the drug; 2) amnesia, by definition, is not noticed; 3) patients do not have the frequent contact with physicians as do our laboratory/research subjects; 4) physician and public education for triazolam side effects is greatly lacking although the current recommended dose has been reduced to 1/4 of the dose originally marketed worldwide as safe and effective. Sleep Research & Treatment Center, Milton S. Hershey Medical Center, Hershey, Pennsylvania 17033

PP 04.32 ASSESSMENT OF SIDE EFFECTS OF ANTIHISTAMINES ON CENTRAL NERVOUS SYSTEM B t Dhor~anintra, C. Bunnag*and T. Sriprasong Limitation of the clinical use of conventional antihistamines are the CNS-related side effects such as drowsiness, sedation and somnolence.

At present there

are quite a lot of new antihistamines claimed to be free from these annoying symptoms.

In order to evaluate such

advantage of some new antihistamines marketed in Thailand; Astemizele, Mequitazine, Acrivastine, a group of assessing methods for both subjective

tests : visual

analogue and alertness rating scales, and objective tests : card sorting, glassbead picking, recording of the reaction time were performed

in both normal

volunteers and allergic patients using a double blind crossover placebo ccntrolled desert. Chlorpheniramine was used as a standard antihistamine. The results revealed that, there was no significant difference of CNS-related side effects between these three antihistamines and placebo, but significantly less than those produced by chlorpheniramine. Division of Allergy and Immunopharmacology, of Pharmacology;

Department

Division of Allergy, Department of

Otolaryngology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.

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EBAST1NE: A NON-SEDATIVE ANTIHISTAMINE HI WITH A SIDE EFFECT PROFILE SIMILAR TO THAT OF PLACEBO X. Luria, O. Bakke, J.P. Perez Modern Hi-antihistamines have a remarkably wide safety margin with few side effects. Ebastine (EB) is a novel non-sedating antihistamine with optimal therapeutic efficacy at a dose of 10 mg o.d. We present an overview of adverse effects reported with EB and placebo (PLC) during the clinical development of the drug as of January 1989. Methods: A total of 2188 patients participated in 12 clinical trials of ebastine (1-40 mg o.d.) in seasonal and perennial allergic rhinitis and chronic urticaria. An analysis of spontaneously reported and elicited (check-list) adverse events was carried out for adults and adolescent patients treated with EB (n = 725) at the established therapeutic dose (10 mg o.d.) in comparison with PLC (n=533) for 1-4 weeks in randomized double blind trials. Dose-effect relationships were also assessed. Results: The following incidences were observed in the EB and in the PLC recipients: Drowsiness (EB: 13.6%, PLC: 15.2%), dry mouth (EB: 12.1%, PLC: 9.2%}, headache (EB: 5.9%, PLC: 9.9%), increased appetite (EB: 7.2%, PLC: 4.1%), asthenia (EB: 4.1%, PLC: 6.4%), stomach uPsets (EB: 5.1%, PLC: 6.9%), nausea (EB: 2.1%, PLC: 2.4%), nervousness (EB: 3.7%, PLC: 4.3%), diarrhoea (EB: 1.5%, PLC: 1.9%), constipation (EB: 1.7%, PLC: 0.9%}, sialorrhea (EB: 1.4%, PLC: 1.1%). No serious adverse reactions were observed in either treatment group. Poor tolerability of the medication was the cause of patient withdrawal in 21 cases with EB and in 19 cases with PLC. Overall, there was no clear relationship between reported side effect and the dose level of EB. Conclusions: Patients with allergic disease treated with EB do not experience drowsiness more often than patients receiving PLC. The full side effect profile of a well tolerated drug cannot be assessed until a large number of patients have been treated. Institute of Research, Laboratorios Almirall, Cardoner 68-74, 08024 Barcelona, Spain

THE GASTROLESIVE POTENCY OF TENOXICAM AND DICLOFENAC. A DOUBLE-BLIND COMPARATIVE TRIAL. H.G. Dammann, R. Kangah, P. MDller, B. Simon Non-steroidal a n t i - i n f l a m m a t o r y drugs (NSAIDs) c o n t r i bute s i g n i f i c a n t l y to the development of gastroduodenal bleeding. In g e n e r a l l y i t is assumed t h a t NSAIDs with an outstanding long h a l f - l i f e l i k e proxicam produce a marked gastroduodenal mucosal damage. 12 healthy male and female subjects aged 25-39 years were administered e i t h e r d i c l o f e n a c 50 mg bid or tenoxicam 20 mg mane on two d i f f e r e q t 14 days treatment periods in a randomized, crossover, double-blind (double dummy technique) design. Only subjects without endoscopically revealed gastroduodenal lesions were e n r o l l e d i n t o the study. Endoscopy was repeated at days 7 and 14 of therapy. Between treatment periods a 4 weeks wash out phase was interposed. The gastrod~odenal lesion score was the f o l l o w i n g : score 0 = no i n j u r y , score I = erythema, score 2 : < 1 0 l esi ons, score 3 = > 1 0 lesions ( pet echi ae/ er osi o n s ) , score 4 = ulcer. There was no s i g n i f i c a n t d i f f e r e n c e in the t o t a l lesion scores between th~ two treatmen~ groups (diclofenac days 7 and 14 0.58 - 0.29 and 9.42 z 0.19, r e s p e c t i v e l y , te~oxicam days 7 and 14 0.42 z 0.19 and 0.42 T 0.15 (mean - SEM)). In no volunteer a peptic ulcer was discovered under therapy. The newly developed NSAID tenoxicam seems to possess a low mucosa damaging potency which is equivalent to diclofenac. H.6. Dammann, Krankenhaus Bethanien, M e r t i n i s t r . 44-46 2000 Hamburg 20, F.R.6.

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Withdrawn

INHIBITION OF INTRACELLULAR ESTERASE ACTIVITY IS AN EARLY INDICATOR OF SULFAMETHOXAZOLE HYDROXYLAMINE (SMX-HA)-INDUCED TOXICITY J.S. Leeder, H.-M. Dosch, S.P. Spielberg We have previously developed a high-sensitivity, high throughput cell viability assay using 2',7'-biscarboxyethyl-5(6)-carboxyfluorescein (BCECF), peripheral blood mononuclear cells (PBMC) and an adaptation of the particle concentration fluorescence (PCFIA) technology (Baxter-Pandex). With this cell concentration fluorescence (CCF) method, SMX-HA, but not its parent c o m p o u n d sulfamethoxazole (SMX), produced a concentration-dependent decrease in cellular fluorescence 18 hr after drug challenge. Based on the properties of BCECF, it was conceivable that SMX-HA toxicity reflected several possible effects, an analysis of which should provide insight into the cell biology of both the toxic process and the detection method. After a 2 hr drug challenge, SMX-HA produced a decrease in cellular BCECF fluorescence which was not accompanied by a corresponding increase in propidium iodide (PI) fluorescence indicating that compromised cell membrane integrity alone did not account for the changes in BCECF fluorescence. Dissipation of pH gradients across the cell membrane with nigericin and monensin demonstrated that decreased intracellular pH was only a small component of SMX-HAinduced toxicity. Loading PBMC with BCECF 30 min prior to SMXHA challenge produced only a 3% decrease in cellular fluorescence at a SMX-HA concentration of 1 mM whereas addition of BCECF after drug challenge resulted in a 71% decrease in fluorescence. Monitoring BCECF cleavage in cell lysates in the presence and absence of SMXHA demonstrated that inhibition of cellular esterase activity accounted for the observed loss of cellular fluorescence after drug exposure. Since changes in cellular BCECF fluorescence at 2 hr correlate well with toxicity at 18 hr, we conclude that SMX-HA inhibition of intracelluar esterase activity is an early indicator of cell death in PBMC. In light of the known polymorphisms in the activity of other esterases (pseudocholinesterase), this may be an important model for determining individual susceptibilities to SMX-induced hypersensitivity reactions. Divisions of Clinical Pharmacology/Toxicology and Immunology/ Rheumatology, The Hospital for Sick Children, and The Centre for Drug Safety Research Toronto, Canada, M5G 1X8.

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SIDE EFFECTS, TOXICITY AND EFFICACY WITH THE U S E O F T E T R A C Y C L I N E IN A S S O C I A T I O N W I T H Q U I N I N E SULPHATE OR AMODIAQUINE HYDROCHLORIDE IN P. f a l c i p a r u m C A R R I E R S . J . M DE S O U Z A and N.P. A B D O N

IS SULFAMETHOXAZOLE HYDROXYLAMINE (SMX-HA) THE PROXIMAL TOXIN FOR SULFAMETHOXAZOLE (SMX) TOXICITY? S.P. Spielberg, J.S. Leeder, A.E. Cribb, H.-M. Dosch Peripheral blood mononuclear cells (PBMC) from patients experiencing hypersensitivity reactions to SMX demonstrate increased in vitro susceptibility to SMX-HA relative to controls. Since these differences could reflect deficiencies in detoxification pathways, we investigated the interaction between SMX-HA and reduced glutathione (GSH). Initially, the stability of various concentrations of SMX-HA in cell-free incubation medium (37~ was monitored for 3 hr by HPLC in the presence and absence of 1 mM GSH. In the absence of GSH, the SMX-HA concentration declined with time at all concentrations tested. When SMX-HA was present at concentrations
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W e r e s t u d i e d 120 c a s e s of f a l c i p a r u m malaria c o m i n g f r o m the a r e a s of m i n i n g g o l d (garimpos) w h e r e the p r e s e n c e of m u l t i d r u g - r e s i s t a n t s t r a i n s is high. C h i l d r e n , p r e g n a n t a n d n u r s i n g women, and m e n o l d e r t h a n 60 y e a r s w e r e r e f u s e d from the study. F o u r s c h e d u l e s w e r e used, two w i t h q u i n i n e (l,0g e a c h t w e l v e hours) and two w i t h a m o d i a q u i n e ( s t a n d a r d dose) b o t h in a t h r e e d a y s course. T e t r a c y c l i n e was u s e d t o g e t h e r q u i n i n e as w e l l as a m o d i a q u i n e , in the same way: 0,5g b.i.d, for 7 d a y s and 1 , 0 g b.i.d, for 5 days. The u s e r s o f q u i n i n e s h o w e d m o r e p r o b l e m s r e l a t e d to the c e n t r a l n e r v o u s system: d i z z i n e s s a n d t i n n i t u s . A l l the 120 p a t i e n t s h a d c o m p l a i n t for the G.I. a p p a r a t u s : b i t t e r taste, n a u s e a , e p i g a s t r a l g i a , v o m i t and d i a r r h o e a . The s i d e e f f e c t s w e r e m i l d a n d t r a n s i e n t and no n e e d e d the i n t e r r u p t i o n o f the t r e a t m e n t or the use o f some s y m p t o m a t i c drug. N o c a s e s of t o x i c i t y o c u r r e d . The e f f i c a c y o f the four s c h e m e s s h o w e d the f o l l o w i n g rates: a) q u i n i n e plus t e t r a c y c l i n e for 5 d a y s - 23 S and 7 RI; b) quinine plus t e t r a c y c l i n e for 7 days - 25 S a n d 5 RI; c) a m o d i a q u i n e p l u s t e t r a c y c l i n e for 5 d a y s - 23 S and 7 RI; d) a m o d i a q u i n e p l u s t e t r a c y c l i n e for 7 d a y s - 20 S a n d i0 RI. In c o n c l u s i o n the s c h e m e b s h o w e d less s i d e - e f f e c t s a n d m o r e e f f i c c a c y a n d m a y to b e r e c o m e n d e d for the t r e a t m e n t of resistant falciparum malaria. UNIDADE DE FARMACOLOGIA CL~NICA DE A N T I P A R A S I T ~ R I O S , N O C L E O DE P A T O L O G I A R E G I O N A L E H I G I E N E , U N I V E R S I D A D E F E D E R A L D O PAR~. AV. G E N E R A L I S S I M O D E O D O R O , 92 66.040 B E L ~ M - PAR/I - B R A S I L

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PATHOPHYSIOLOGY AND CLINICAL COURSEOF AGRANULOCYTOSIS ASSO CIATED WITH PARENTERAL HIGH DOSESOF B-LACTAMANTIBIOTICS J Juan, E P4rez, X~Carn4, L Ib6~ez, and JR Laporte In spite of the large number of case-reports on B-lactam-induced agranulocytosis, clear diagnostic c r i t e r i a of this condition have not been proposed, neither a series of cases large enough has been systematically studied. A series of 21 cases of parenteral -]actam-induced agranulocytosis has been assembled in seven years, from 18 hospitals participating in the Catalan network of the International Agranulocytosis and Aplastic Anemia Study (IAAAS). For each case, causality relationships were established using a modification of Karch and Lasagna's algorithm. The induction period, i . e . the period of time elapsed between starting the allegedly causal treatment and the appearance of the symptoms of agranulocytosis averaged 20 days (95% CI 16.9-22.9, range 3 to 36 days). Only in one patient a sharp drop of the granulocyte count was recorded, and in another patient a gradual drop was seen. No information is available concerning the remaining patients. The median number of days between drug withdrawal and anaylitical recovery was 6.5 days (95 CI 4.7-8.3, range 2 to 11). 6-1actam-induced agranulocytosis appears after a long exposure -13 days or more in a l l but one case- to very high doses of the drug. In 11 out of the 21 cases the disease was discovered in a routine laboratory screen. Seven cases presented hipersensitivity symptoms before or during the episode of agranulocytosis. Comparedwith the clinical course observed in other cases included in the IAAAS, the recovery of the granulocyte count seemed faster in the cases attributed toB-lactams. Bone marrow aspirate did not show any differences from the bone marrow specimens of cases attributed to other drugs. We conclude that regular monitoring of the leucocyte count in a l l patients treated with high doses of 6-1actam antibiotics f o r periods longer than twelve days would be advisable. Servei de Farmacologia Clfnica. CS Vall d'Hebron. 08035 Barcelona.

CLOZAPINE-INDUCED NEUTROPENIA AND AGI~ANULOCYTOSIS IN FINLAND E. S. Palva, E, %Nu0tto and L, M~Ikonen Clozapine, an atypical neuroleptic drug, was launched in Finland in 1975. During a few months period, 17 cases of neutropenia or agranulocytosis were reported, 8 of these cases being fatal (Idanpaan-Heikkila et al., Europ, J. Clin. Pharmacol, I I, 193, 1977), The risk of neutropenia was calculated to be 0.6 % and that of agranulocytosis 0.5 %, Clozapine was subsequently withdrawn from the Finnish market. Thereafter clozapine has been available on special licenses only. Its use is restricted for hospitalized patients and the white blood cell count has to be monitored two times weekly, During the years 1982-1988, 35 cases of neutropenia and 25 cases of agranulocytosis related to clozapine treatment have been reported to the Adverse Drug Reaction Register in Finland. In accordance with the earlier Finnish observations, the appearance of clozapine-related neutropenia or agranulocytosis has proved to be stable, roughly I in I00-150 patient years. However, with these precautions taken, only one fatal case has been observed during these years. It seems that clozapine-induced blood dyscrasias are too common to allow its unrestricted use, In carefully selected cases resistant to other neuroleptic treatment, it is possible to use clozapine relatively safely when the patients are closely monitored. National Medicines Control Laboratory, Mannerheimintie 166, SF-00300 Helsinki, Finland

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GRANULOCYTOPENIA AND THROMBOCYTOPENIA INDUCED BY LOW-DOSE FLUCYTOSINE IN PATIENTS WITH CRYPTOCOCCAL MENINGITIS UNDER COMBINATION WITH AMPHOTERICINB B K. Bhindo, Y. Matsumoto, Y. Hashimoto, T. Mizuno, A. Ito, and T. Okuho Both two patients were admitted complaining of fever and headache. They were diagnosed as cryptococcal meningitis, since cryptococcus neoformans were found in an India Ink preparation of their cerebrospinal fluids. Both amphotericine B and flucytosine, the latter used in a low dose (50mg/kg/day), were concomitantly administered to the patients. Before the combination therapy, ~n the two pa- 3 tients the white blood cells were 7200/mm ~ with 4300/mm of granuloeytes a~d 8900 with 51~0, and thrsmbocyte cell counts were 17xlO~/mm and 23xlO-,respectively. BUN and creatinine in the serums were 16mg/dl and l.Omg/dl, 17 and 0.9, as low as normal, respectively. During administration of 50mg of amphotericine B, BUN and creatinine in the serums gradually rose to 3 2 a n d 2.7, 35 and 3.0, respectively, whereas the granulocyte and thrombocy~e cell counts decreased gradually to 1960 and l. BxlO , 2300 and 2.3xi0-, respectively. After the combination therapy was discontinued, the granuloeyte and thrombocyte cell counts increased following the recovery of BUN and creatinine levels in the serums. The second administration of amphoterieine B alone induced the increase of BUN and creatinine, however, neither granulocytopenia nor thromhocytopenia occurred. These results suggest that the mechanisms of granulocytopenia and thrombocytopenia may be toxic reactions of flucytosine to bone marrow in the azotemic state caused by amphoterieine B. Hence our report emphasizes the need for greater attention to granuloeytopenia and thromboeytopenia in patients recieving treatment with both of amphotericine B and flueytosine, even though the combined flucytosone was used in a low dose. The First Department of Internal Medicine, Yokohama City University School of Medicine, 3-46, Urafune-cho, Minami-ku, Yokohama 232, Japan.

CIMETIDINE INJECTION AND BLOODD~SORDERS A.Sakagami, R. Hama, S. Izumi, K. Mori, M. Hashinotsume, H. Miura, Y. Okamoto, T. Arima and S. Murata, H. Endo Three cases of leukopenia and/or thrombocytopeniaat this hospital brought us to conduct a retrospective-prospective study on blood disorders and use of cimetidine injection. tMethods ] Eligible patients were 198 whose main diseases were peptic ulcers and/or stomach malignancis with data available. Of these 90 were cimetidine injection users(av, as users) and 108 were non-users, Data on age, sex, body weight, main diseases, complications(malignancies, l i v e r diseases etc.), transfusions, laboratory data(CBC, LST, LAT, BUN, Cr.), use of cimetidine(injection and/or tablet) and other drugs including dose and duration of the treatment were obtained from medical records. [Results ] Most of the base-line data were not significantly different except the frequency of acute bleeding and that of abnormal renal function test(both were higher in users) and except that of anti-cancer agents users(higher in non-users). Frequency of i n i t i a l abnormal blood count(WBC<4,0OO/mm3and/or PLT<150,OOO/mm3) was not significantly different. Frequency of leukopenia was significantly higher in users than in non-users (WBC<3,500/mm~;17.6 vs 7.4%, WBC<2,5OO/mm3; 4.4 vs 0%). Frequencyof thrembocytopenia(PLT<120,OOO/mm3) was also significantly higher in users(24.4 vs 12.6%). Risk was higher in patients with liver disease and/or with i n i t i a l abnormal blood counts. {Discussion and conclusions] Frequencyof blood disorders in cimetidine users was reported only 0.04%(5/13,470) previously. But in this study the frequency of blood disorders induced by cimetidine injection seemedmuch morer. Bone-marrowtoxicity of H2-antagonists is thought to be related to its a b i l i t y to block cell-cycle changes in the pluripotent stem cell. So H2antagonists might influence blood counts much more than usual because differenciation of stem cells might be necessitated after massivebleeding and/or after a surgical operation. This study indicates that the blood disorders in cimetidine i n j e c t i o n treatment may be c l o s e l y r e l a t e d to i t s pharmacological actions.

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DRUG-INDUCED SEVERE SKIN REACTIONS IN FINLAND E. J. Nuotto, E. S. Palva, L. Malkonen The Finnish Adverse Drug Reaction Register was searched for the years 1978-1988 in an attempt to evaluate data relating to reported drug-induced severe skin reactions: Erythema multiforme (EM), Stevens-Johnson syndrome (SJS) and Lyell's syndrome (LS). The total number of all reports submitted during the 1 l=year period was 6131 (455-726 per year) and the total number of all skin reactions reported was 2262 ( 37'% of all cases). A total of 1.6 %of all cases were classified as severe skin reactions, comprising 55 cases of EM, 32 cases of SJS and 11 cases of LS. As expected, almost half of the reports (43 cases) were related to the use of antimicrobial agents (sulfonamides, trimethoprim, tetracyclines, aminopenicillins and cephalosporins). Carbamazepine, phenobarbital and other CNS-active drugs were related to the severe skin reactions in 17 cases and non-steroidal anti-inflammatory drugs in 14 cases. It was interesting to notice that in spite of their widespread use, propionic acid derivatives (ibuprofen, naproxen and ketoprofen) did not appear in these adverse reaction reports. On the other hand, diltiazem, after, being only for 2 years on the Finn2sh market, was related to 4 reports of EM and 2 reports of SJS. It seems that although diltiazem seems to be otherwise well tolerated in most patients, it induces more severe skin reactions than other calcium entry blockers. National Medicines Control Laboratory, Mannerheimintie 166, SF-00300 Helsinki, Finland

ISOLATED CELLS AS M O D E L S FOR E V A L U A T I O N OF S I D E AND A D V E R S E DRUG REACTIONS. R.J.Nos&I, K.Dr&bikov&, V.Jancinov&, J . P e c i v o v & In c a r d i o v a s c u l a r diseases the i n t e r a c t i o n of b e t a a d r e n o c e p t o r b l o c k i n g (BAB) drugs w i t h blood platelets was d e m o n s t r a t e d as a result of side effects. On the other hand, for studying the adverse reactions of BAB drugs in asthmatics, isolated mast cells provide a suitable model. Histamine liberation w i t h o u t d e g r a n u l a t i o n oc curred from isolated mast cells t r e a t e d w i t h lipophilie BAB drugs such as exaprolol, propranolol and K~ 1124. This was accompanied by intracellufar c a l c i u m displacement, decrease in phosphatidylinositol turnover, arachidonic acid liberation, increase in m e m b r a n e fluidity, and e n h a n c e d binding with intracellular p e n e t r a t i o n of these drugs. All studied BAB drugs i n h i b i t e d the uptake of e x t r a c e l l u l a r h i s t a m i n e and serotonin into the mast cells. BAB drugs inhibited stimulated a g g r e g a t i o n of blood platelets depending on their liposolubility. Exaprolol, propranolol, m e t i p r a n o l o l and alprenolol were found to be the most active. The inhibition followed the rank order of stimuli: collagen>thrombin>ADP and correlated with intracellular c a l c i u m displacement, m e m b r a n e fluidization, p h o s p h o i n o s i t i d e turnover and archidonic acid liberation. The e x p e r i m e n t a l data obtained at c e l l u l a r and m o l e c u l a r level correlated w i t h clinical findings in patients treated with BAB drugs. Nonreceptor, rather than receptor interaction, seems to be involved in the cellular response for side and adverse reactions. Institute of E x p e r i m e n t a l Pharmacology, CPS, Sloyak A c a d e m y of Sciences, DGbravsk& 9, 842 16 Bratislava, C z e c h o s l o v a k i a

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PRELIMINARYCHARACTERIZATIONOF AN ANIMALMODELOF SULFONAMIDE HYPERSENSITIVITYREACTIONS A. E. Cribb and S. P. Spielberg We have previously established the metabolic basis of sulfonamide hypersensitivity reactions (SHR) in humans: slow acetylation and decreased detoxification of P450 generated sulfonamide reactive metabolites (SRM), as demonstrated using an in vitroperipheral blood mononuclear cell (PBMC) toxicity assay. Investigation of contributing factors and lreatment interventions requires an animal model. SHR in dogs, characterized by polyarthrJtis, fever, blood dyscrasias, and drug eruptions, has been reported. Doberman Pinschers are the predominant breed affected. To assess the utility of the Doberman as an animal model, we characterized in vitro sulfonamide microsomal metabolism and SRM cytoloxicity in dogs. Microsomes isolated from dog liver are capab/e of metabolizing suIfonamides and microsome-generated SRM are toxic to canine PBMC. A Doberman Pinscher with a known SHR showed a significantly greater PBMC cytotoxicity than control mixed breed dogs in the microsomal toxicity assay (16.2 • 3% vs. 1.2 • 2% at 2mM sulfadiazine). Using the synthetic hydroxylamine metabolite of sulfamethoxazole, we investigated in vitro cytotoxicity in 15 Dobermans (including the above) and 10 mixed breeds. A s)gnificant number of Dobermans (n=7) showed cytotoxicity, as indicated by LD-50 values, outside the 95% C.I. for mixed breeds (Chi-square; p<0.05). The Doberman sample was divided into two groups based on Probit transformation. One group (including the Doberman with a SHR; n=7) showed a significantly greater cytotoxicity than mixed breeds (LD-50=56 + 9.5#.M vs.177 _+ 19#M; p=0.001), while the other group (n=8) showed similar toxicity to the mixed breeds (212 + 33 FM). A polymorphism in the ability of Dobermans to detoxify SRM suggests detoxification capacity is involved in predisposition to SHR in dogs. Dogs do not acetylate sulfonamides. Therefore, the metabolic basis of SHR in dogs and man may be similar and a canine model valuable in investigating sulfonamide hypersensitivity reactions. Division of Clinical Pharmacology, Hospital for Sick Children, Toronto, Canada M5G 1X8

EFFECT OF RANITIDINE ON THE RABBIT ISOLATED JEJUNUM O. Sabzevari and A. R. Dehpour R a n i t i d i n e i s a s p e c i f i c and p o t e n t H 2 - r e c e p t o r a n t a gonist w i d e l y used in t h e e f f e c t i v e t h e r a p y o f p e p t i c u l c e r d i s e a s e . I t has been r e p o r t e d t h a t i t a l s o exerts cholinergic-like e f f e c t s a t the same concent r a t i o n s which b l o c k H 2 - r e c e p t o r s . We have s t u d i e d t h e e f f e c t s o f r a n i t i d i n e on the r a b b i t i s o l a t e d jejunum which is p a r t i c u l a r l y sensitive to muscarinic agonists and a n t a g o n i s t s in o r d e r t o d e f i n e these a p p a r e n t l y c h o l i n o m i m e t i c a c t i o n s . A l b i n o r a b b i t s o f e i t h e r sex were used. The desected muscle was suspended in a 10 ml bath c o n t a i n i n g Tyrode s o l u t i o n and bubbled w i t h 95% 02 and 5% C02. A f t e r a h a l f hour e q u i l i b r a t i o n p e r i o d , a p p r o p r i a t e q u a n t i t i e s o f r a n i t i d i n e were added to the media and ensuing changes in t h e muscle t e n s i o n were measured. R a n i t i d i n e ( 0 . 5 - 5 0 0 ~M) induced c o n t r a c t i o n in a dose dependent manner. The response was antagonized by a t r o p i n e ( 0 . 2 ~M). The o n s e t o f ranitidine acti:on was s l o w ; the peak e f f e c t was a t t a i n e d a f t e r s e v e r a l minutes and the e f f e c t was s t i l l e v i d e n t a f t e r s e v e r a l washings. No t a c h y p h y l a x i s was observed. The ED50 v a l u e o f r a n i t i d i n e was found t o be 76 ~M. The drug c o n c e f i t r a t i o n t o induce c o n t r a c t i o n s was c l o s e d t o the t h e r a p e u t i c l e v e l s . The p r e s e n t data i s in agreement w i t h o t h e r i n v e s t i g a t o r s showing c h o l i n o m i m e t i c - a c t i v i t y o f the drug on the other tissues. Dept. o f T o x i c o l o g y , C o l l e g e o f Pharmacy, U n i v e r s i t y o f Tehran. Tehran-IPJ~N

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THE EFFECT OF PLACEI~ON POST-OPERATIVE PAIN

M. T u l u n a y , F. Cankat T u l u n a y , A l k i s , S. D e m i r a l p

C.

Tezcan,

N.

i'n t h i s s t u d y we i n v e s t i g a t e d the analgesic eff e c t of p l a c e b o ( 0 . 0 9 % NaC1), M o r p h i n e , D y p i r o n (non-narcotic analgesic) on p o s t - o p e r a t i v e pain in a d o u b l e - b l i n d f a s h i o n . A f t e r c o m p l e t i o n of s u r g e r y p a t i e n t s w e r e r a n d o m l y a s s i g n e d in to 4 g r o u p s (12 p a t i e n t s in e a c h g r o u p ) . Group I (control g r o u p ) was n o t g i v e n any m e d i c a t i o n during study period. The o t h e r 3 groups received i.v. placebo but they were told that they are receiving a pain killer (Group I I ) , m o r p h i n e (Group I I I ) and d y p i r o n (Group IV). Forty-five min a f t e r first placebo injections patients were told they will receive t h e 2nd d o s e of p r e v i o u s l y i n j e c t e d d r u g s . At t h i s t i m e G r o u p I I r e c e i v e d 2nd d o s e o f p l a c e b o , Group l I I and IV r e c e i v e d i . v . 10 mg o f m o r p h i n e and 1 g of d y p i r o n, respectively. Pain assessments (VAS, VRS-4 and % p a i n s c o r e ) w e r e made a p proximately 1 hr after operation a n d 45 m i n after injections. F i r s t d o s e of p l a c e b o d i d n o t p r o d u c e d any s i g n i f i c a n t analgesic effect in 3 treatment g r o u p s b u t s e c o n d d o s e of p l a c e b o produced significant analgesic effect in G r o u p I. M o r p h i n e and d y p i r o n p r o d u c e d s i g n i f i c a n t analgesic effect 45 m i n a f t e r injections. However p a i n i n t e n s i t y s l o w l y d e c r e a s e d in c o n trol group but this decrease was not significantly different daring study period. This results suggest that convincing of patients t o d r u g h a s n o t any r o l e in p l a c e b o response. On t h e o t h e r hand, it seems that repeated dose has more important role in placebo response. Dept. of Anesthesiology, M e d i c a l S c h . o f Ankara University, Iba| Sina Hospital, Ankara, Turkey.

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A. ~ a ~ . During investigation of a novel am~pound with potential memory enhancing properties nine parallel forms of the Buschke Selective Reminding Test were required for repeated measures testing. To create word lists of cfm~arable difficulty a previously published methodology and master list were used (H.C. Kraemer et al., Psych. Bull. 94, 367-380, 1983). Over several studies data on each of the nine forms were obtained for 21 subjects, average age 30, who received a single placebo dose. These data were analysed to assess the equivalence of the test forms. Analysis of variance revealed a highly significant subject effect. As large inter-individual differences in performance had been observed during testing the subjects were eategorised as poor or good performers. The criterion for poor performance was a consistent long-term retrieval score at least one standard deviation below the mean established for a group of 24 subjects of comparable age. In a subsequent analysis the test forms were not found to differ to a statistically significant degree, confirming the utility of the m e ~ o l o g y and master list for the creation of ur~atched word lists of similar difficulty. Institute of Clinical Pharmacology, Sir Patrick Den's Hospital, Lr. Grand Canal St., Dublin 2.

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IMPORTANCE OF SUGGESTION IN n4E PLACEE~DMEC:HANISM C. Granveeu, C. Crowe-McCann, L. Silvy-Leligeis, M. Frisk and P. Meyer The u n d e r l y i n g mechanisms of t h e placebo e f f e c t e r e l a r g e l y unknown. The c o m p l e x i t y o f human p e r c e p t i o n and t h e d i v e r s i t y of t h e p a t i e n t groups s t u d ied have made i t d i f f i c u l t t o c h a r a c t e r i z e t h e persons who respond to p l a c e bo. The a s s o c i a t i o n , i n a homogeneous group of h e a l t h y s u b j e c t s , between t h e p l a c e b o response and p s y c h o l o g i c a l c h a r a c t e r i s t i c s has Peer t h e s u b j e c t of v e r y few s t u d i e s . The purpose of t h i s s t u d y was i ) t o c l a r i f y t h e r o l e of s u g g e s t i o n i n t h e p l a c e b o response, i i ) t o i d e n t i f y a p e r s o n a l i t y p r o f i l e of t h e placebo r e s p o n d e r s ; ' i i i ) to investigate the cardiovascular response ( b l o o d p r e s s u r e (BP) and h e a r t r a t e (HR)) t o a s t r e s s f u l s i t u a t i o n during t r e a t m e n t w i t h e i t h e r an a n x l o I y t i c o r placebo ( w i t h and w i t h o u t suggestion). Methods: This single blind cross over randomized study included one baseline add 5 treatment sequences comparing alprazoiam (0,5 mg p.o.), placebo (sin ~ gle placebo) and placebo with a verbal suggestion of an anxiolytic action by one of the investigators (active piacebo). 32 young volunteers participated; psychological testing (Catteii 16 PF, SCL go (R)) was carried out prior to study. A standard procedure was followed during each session, BP + HR were measured repeatedly and mental arithmetic (lterative subtractions) was used es the stress test, In the subjects who displayed at baseline a significant reaction (increase in systolic BP and/or H R ~ 20%), a positive response to placebo was regarded as an absolute variation of systolic BP and HR during stress o f ~ 1 0 ~ . Analysis of variance was applied to cha~ges within and between groups. R e s u l t s : H a l f of t h e v o l u n t e e r s responded t o t h e p l a c e b o (most of them t o t h e a c t i v e p l a c e b o o n l y , and t h e o t h e r s t o s i n g l e p l a c e b o ) . Comparing 8P and HR changes of t h e p l a c e b o r e s p o n d e r s end non r e s p e n d e r s , a s i g n i f i c a n t diff e r e n c e was found o n l y f o r t h e a c t i v e p l a c e b o (BP: p ~ , 0 2 , HR: p ~ , O l ) , An a s s o c i a t i o n was found between a p o s i t i v e p l a c e b o response and a l o w e r s c o r e of F a c t o r 0 I V i n t h e C a t t e l l 16 PF ( p ~ . 0 2 ) . T h i s i s a measure of i n d e p e n dence vs s u b m i s s i o n and r e s u l t s s u g g e s t t h a t t h e responders a r e more s u b m i s s i v e , c o n s e r v a t i v e and dependent. C o n c l u s i o n : The p r e s e n t s t u d y , performed w i t h o b j e c t i v e p a r a m e t e r s , shows t h e i m p o r t a n c e of some p s y c h o l o g i c a l c h a r a c t e r i s t i c s i n t h e placebo e f f e c t . I t has beam found t h a t t h i s e f f e c t o c c u r r e d i n s u b j e c t s p r e s e n t i n g s u b m i s s i ve c h a r a c t e r i s t i c s and i l l u s t r a t e s t h e i m p o r t a n c e of s u g g e s t i o n . Such d a t a c o u l d be t a k e n i n a c c o u n t i n c l i n i c a l trials, i f same c o n c l u s i o n s were reached w i t h o t h e r types of s t r e s s . Dept of Pharmacology, U7 INSEF~4/UA 518 CNRS, H ~ p i t a l Sevres, 75015 P a r i s , France

M~4ORY A S S E S S M ~ : E Q U I V A L ~ WE~D LISTS FC~ THE HUSCHKE SELECTIVE R~4INDING T ~ T . R.F. (ben~ T. Kinsellaf R. Lamber M. Kenny and

Necker,

161

rue de

PROCAINE HYDROCHLORIDEAS A LIMBIC SYSTEM CTIVATOR: DISTRIBUTION OF 14C-PROCAINE IN THE RAT BRAIN. P. Sanhueza, D. Simko, K,E. Livingston. I t has been postulated that procaine hydrochloride administered intravenously as a bolus is a limbic system a c t i v a t o r and a c o r t i c a l suppressor. (K.Livingston. Limbic mechanisms, Plenum, New York, p.p 521-533, 1978). Human studies indicate that procaine produces behavioral and subjective effects li~e those produced by d i r e c t e l e c t r i c a l stimulation of the human limbic system. (R. Adamec. Limbic Epilepsy and the dyscontrol syndrom: Elsevier, North Holland Medical press, Amsterdam, p.p 117-131,1979). To gain understanding into such phenomena we studied the patterns of d i s t r i b u t i o n of 14-C procaine hydrochloride (14C-P) in the rat brain following intraperitoneal (ip) and i n t r a a r t e r i a l (ia) administration. Procaine-HCl lOmg/ kg in a volume of 0.2 ml labeled with 14C-P (2uCu/ml) was administered to hooded rats either through the femoral artery or i n t r a p e r i t o n e a l l y . Animals were k i l l e d at d i f f e r e n t i n t e r v a l s and r a d i o a c t i v i t y in blood, brain, l i v e r , kidney and ommental f a t was determined. Brain d i s t r i b u t i o n was determined following dissection of the brain in 16 specific areas. Dose-nesponsecurves in blood and brain were also done. Highest levels of the isotope were found.in l i v e r and kidney, followed by brain. Peak levels in brain after ia injection occurred earlier and were 3.8 times higher than after ip injection. No differences in distribution in specific areas of the brain were found. The estimated procaine concentrations in brain were in the range in which pharmacological effects of procaine in the central nervous system in experimental studies has been described. Our results suggest that central accumulation of procaine depends upon the route of administraion and that i t s effects on the limbic system are not due to differential brain regional distribution. Department of Psychiatry. Toronto Western Hospital. Carvell Wing. 399 Bathurst St. Toronto, Ontario. M5T 2S8.

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INTERACTION BETWEEN PAST EXPERIENCE AND BARBITURATE POSTHYPNOTIC HYPERACTIVITY M. Sansone. F. Pavone. M. Battaa]ia and J. Vetulani Although generally cegarded as sedatives, under some conditions, barbiturates may stimulate locomotor activity in laboratory animals. We have recently observed that hyperactivity occurs not only in mice r e c e i v i n g subhypnotio doses of pentobarbita], but also in animals recovering from pentobarbital-indueed anesthesia. Since novelty of the environment is a very important factor in the locomotor stimulatory action of drugs, in the present study we investigated how a previous experience affects the stimulatory action of a subhynotic dose of pentobarbita] and the posthypnotic hyperactivity. Locomotor activity of CD-I mice, tested in an unfamiliar environment (toggle-floor box), was increased either by a subhypnotic dose (20 mg/kg) of pentobarbital or after recovery from pentobarbitai-induced (50 mg/kg) anesthesia. On the contrary, when mice were tested 6 h after a single exposure to the apparatus, pentobarbital in either case failed to produce hyperactivity. The results demonstrate that novelty of the environment is crucial for the locomotor stimulation induced by a subhypnotic dose o f pentobarbital as well as for the hyperactivity exhibited by mice during recovery from pentobarbital anesthesia. It was already known that the locomotor effects exerted by various drugs can be less expressed or absent in a familiar test apparatus. Thus, the interaction between past experience and the effect of the subhypnotic dose of pentobarbital was not unexpected. Conversely, the interaction between past experience and posthypnotic hyperactivity was not so predictable, since the past experience could have been distorted by barbiturate anesthesia. The present results demonstrate that mice recovering from barbiturate anesthesia maintain susceptibility to the exteroceptive stimuli provided by a novel environment and knowledge of the environment acquired during past experience. Istituto di Psieobiologia e PsieofarmacoIogia, CNR, via Reno i, 00198 Roma, Italy

C H R O N O P H A R M A C O L O G Y O F O R A L N I F E D I P I N E ~IN HEALTHY SUBJECTS B . L e m m e r I ~ S.Behne ~ and H.J.Becker 2 T h e pharmacokinetics and the hemodynamic effects of hired• (CordicantR Kapsel, I0 mg) w e r e studied in 12

PP 04.51 A COMPARATIVE STUDY OF DIMETHYL-AND DIETHYLAMINOETHANOL USING AN INHIBITORY AVOIDANCE TASK AND A MOTOR PARADIGM IN THE RAT E. Kafetzopoulos and M. Marselos I t has been proposed that dimethylaminoethanol may ameliorate t a r d i v e dyskinesia, as well as some other neurological diseases. An influence on a t t e n t i o n , arousal and memory has also been suggested, possibly mediated through central c h o l i n e r g i c mechanisms. The purpose o f the present study was to compare dimethylaminoethanol and diethylaminoethanol e f f e c t s in the r a t , the l a t t e r beeing a close s t r u c t u r a l analog and expected to have some s i m i l a r p r o p e r t i e s . Using an i n h i b i t o r y avoidance task (step-down avoidance) i t was found t h a t both drugs when given 30 min p r e - t r i a l l y in 25 or 50 mg/kg, showed a s t a t i s t i c a l l y b e t t e r r e t e n t i o n o f the task a f t e r 24 hours than the s a l i n e treated control r a t s . Other groups o f rats were tested in the open f i e l d a f t e r the same doses o f the druds and not s i g n i f i c a n t change o f t h e i r motor a c t i v i t y was observed. On the contrary, both drugs were e f f e c t i v e in producing i p s i l a t e r a l turning a f t e r u n i l a t e r a l lesion o f the substantia nigra with i b o t e n i c acid. These r e s u l t s i n d i c a t e t h a t these two drugs may have a s i m i l a r pharmacological p r o f i l e i n f l u e n c i n g avoidance learning and s t r i a t a l motor mechanisms. Dept. o f Pharmacology, Medical School, U n i v e r s i t y of loannina, loannina, Greece

healthy male subjects after oral drug application at either 8~176or at 19~176 local time. Automatic 24-hours recordings of systolic and diastolic blood pressure [BP] and heart rate [HR] were performed with a portable device (PARPHISIO-PORT, kardiotec, Mannhaim). Control hemodynamic parameters displayed significant daily variations (ANOVA:p <0.001) and drug effects were calculated in relation to the individual circadian controls. At either occasion blood samples were taken at 0, 15, 30, 45, 60, 90, 120, 210, 300, 720 min after drug intake. Nifedipine plasma concentrations were determined by gaschromatography. The results demonstrate significant daily variations in the pharmacokinetics of nifedipine: In all of the 12 subjects peak drug concentrations were higher after morning than after evening dosing (mean+_SD:Cmax: 82.0 +- 22.6 vs. 45.7 -+ 22.1 ngjml, p<0.01) with tmax being significantly shorter after morning than after evening dosing (22.5 • 10.1 rain vs. 37.5 • 13.6 rain, p<0.01). Bioavailability was greatly reduced after evening dosing (-36.5%) as calculated by the AUCo_2h. Maximum decrease in systolic and diastolic BP, maximum increase in HR and time to peak drug effects were not circadian phase-dependent; cumulative drug effect in HR increase [AUCo_3~] was significantly greater after evening than after morning dosing (20.9 i 11.0 vs. 8.3 • 12.0 b/minJ3h, p<0.05). In conclusion, the results give evidence that the pharmacokinetics of nifedipine vary significantly with time of day. Furthermore, the data indicate a circadian phase-dependency in the dose response relationship of this calcium channel blocker. The study was supported by Mundipharma, Limburg, and approved by the Ethical Committee, University Frankfurt. ~Zentrum der Pharmakologie, J.W. Goethe- UniversitY• D-6000 Frankfurt]M, 2Stadtkrankenhaus Hanau, F.R.G.

PP 05.02 CHRONOPHARMACOLOGY OF iSOSORBIDE-5MONONITRATE (IMMEDIATE RELEASE, RETARD

FORMULATION) IN HEALTHY SUBJECTS B.Scheidel~ G.Lenhard2, H.Blume1~ H.J.Becker 3 and B. Lemmer 4 The pharmacokinetics and hemodynamic effects on blood pressure [BP] and heart rate [HR] of isosorhide-5-mononitrate [IS-5-MN] in an immediate release formulation (A, IS-5-MN Stada) and a retard formulation (B, Coleb-Duril e s R) w e r e s t u d i e d i n h e a l t h y s u b j e c t s a f t e r o r a l d r u g i n t a k e of 60 m g a t t w o d i f f e r e n t t i m e s of d a y ( A : 6 3 ~ 18~~ B:8~176176176 Plasma concentrations of I S - 5 - M N were determined by a capillary gaschromatographic method w i t h E C D - d e t e c t i o n . D r u g e f f e c t s w e r e c a l c u l a t e d in r e l a t i o n to c i r c a d i a n c o n t r o l v a l u e s i n BP a n d H R . S i g n i f i c a n t daily variations were found in the pharmacokinetics of the immediate release formulation (A) but not for the retard formulation (B). For A tmax (mean• was 0.9 -+ 0.9h and 2.1 _+ 1.2h, p(0.01 after the morning and evening administration, reap, Cmaxand t 89 were not significantly different. For B tmax was 5.2 + 2.3h and 4.9 • 0.9h for morning and evening administration, reap., with no difference in Cmax and t89 However, after either formulation maximum decrease in systolic BP and maximum increase in H R occurred at the same time as peak drug concentrations after morning application and in advance of peak drug concentration after evening d r u g application. T h e results give evidence that even the kind of drug formulation m a y be important whether or not the pharmacokinet• are circadian phase-dependent. Furthermore, data indicate a circadian phase-dependency in the dose response relationship of IS-5-MN. The studies were supported b y Astra, Wedel, and Stada AG, Bad u

~Zentrallaboratorium Dtsch. Apotheker, Eschborn, 21nst. Kiln. Pharmakologie, Overath, ~Stadtkrankenhaus Hanau, 4Zentrum der Pharmakologie, J .W. Goethe-Universit~it, Frankfurt/M, F.R.G.

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CHRONOPHARMACOKINETIC STUDY OK VALPROIC A C I D IN MAN:CON~ARISON OF ORAL AND RECTAL ADMINISTRATION Y . Y O S H I Y A M A * , S . N A K A N O * * , F . T O M O N A G A * and N.OGAWA ~*

CHRONOPHAP~COLOGICAL ASPECTS OP H Y P O T E N S I V E TREATMENT WITH PRAZOSIN. H. Adamska-Dyniewsks, S. Dziekas The goal of the study was the individualisation of treatment with p r a z o s i n om the base of automatic blood pressure m o n i t o r i n g /Accutracker-Oxford/. The group consisted of 22 patients with mild or m o d e r a t e h y p e r t e n s i o n /the m e a n age 54• yr/. There were 3 stages of p r a z o s i n monotherapy. Stage I./3 m o n t h s / - the increasing dosing of p r a t o s i n starting with 0,5 mg up to dose clinlcaly needed. Stage II /9 months/ - hypotensive treatment with stable doses from I to 7 mg /the m e a n daily dose 3,1+1,8 mg/. Stage III /6 m o n t h s / - i n d i v i d u a l i a t i ~ n of dosing on the base of chronofarmacological observations, c o n t i n u a t i o n of treatment. ,,Natural" profile of blood pressure was less disturbed ~ e n p r a z s ~ i n was prescribed twice daily at 8- and 13 , than in the m o r n i n g and in the evening. In some cases p r a z o s i n had to be used thrice daily. The m e a n blood pressures before treatment were: 185/104, after I stage 152/88, after II stage 157/90, a f t e r III stage 145/84 m m Hg. A good or very good effectiveness of p r a z o s i n as h y p o t e n s i v e drug was observed in 65% of patients.

C i r c a d i a n s t a g e - d e p e n d e n t c h a n g e s of v a l p r o i c a c i d (VPA) k i n e t i c s h a v e been r e p o r t e d in m a n and r o d e n t s . C i r c a d i a n s t a g e - d e p e n d e n t c h a n g e s of a n t i c o n v u l s a n t a c t i v i t y of t h e drug h a v e also b e e n d e m o n s t r a t e d in m i c e a f t e r oral a d m i n i s t r a t i o n and this finding s e e m s to be due to t h e t i m e - d e p e n d e n t c h a n g e s in VPA kinetics. T i m e - d e p e n d e n t g a s t r i c e m p t y i n g t i m e i n f l u e n c e d by t h e a m o u n t of food r e m a i n i n g in the s t o m a c h m a y play a m a j o r role in c r e a t i n g t h e s e c h a n g e s in VPA k i n e t i c s a f t e r o r a l a d m i n i s t r a t i o n . If so, the r e c t a l a d m i n i s t r a t i o n of the drug m a y e l i m i n a t e t h e t i m e - d e p e n d e n t c h a n g e s of VPA kinetics. This s t u d y w a s designed to e x a m i n e this possibility. Eight h e a l t h y young m a l e v o l u n t e e r s took a single oral or r e c t a l dose of VPA 400 rag, in a f o r m of sodium v a l p r o a t e , on t w o o c c a s i o n s , in the m o r n i n g (0830) or in the evening (2030), in an e x p e r i m e n t a l design using two L a t i n squares. Meals w e r e s t a n d a r d i z e d to fit the s u b j e c t s ' usual m e a l a m o u n t . Meal t i m e was f r o m 0800 to 0810 for b r e a k f a s t and f r o m 1800 to !830 for dinner. Subjects w e r e s y n c h r o n i z e d with diurnal a c t i v i t y and n o c t u r n a l r e s t as t h e i r usual life. Blood s a m p l e s w e r e d r a w n 0 . 5 , 1 , 1 . 5 , 2 , 3 , 4 , 6 , 1 2 , 2 4 , 3 6 and 48 hr a f t e r dosing. P l a s m a VPA c o n c e n t r a t i o n s w e r e d e t e r m i n e d by a g a s c h r o m a t o g r a p h y with FID d e t e c t o r . A f t e r oral a d m i n i s t r a t i o n , m e a n t o t a l VPA c o n c e n t r a t i o n s in p l a s m a w e r e s i g n i f i c a n t l y higher in t h e m o r n i n g t h a n in the evening during t h e a b s o r p t i o n phase. C m a x w a s higher (p<0.05), t m a x w a s s h o r t e r (p<0.05) and a b s o r p t i o n r a t e c o n s t a n t (ka) was l a r g e r (p<0.05) for VPA in the m o r n i n g t h a n in the e v e n i n g , a l t h o u g h no d i f f e r e n c e was d e m o n s t r a t e d in o t h e r p h a r m a e o k i n e t i c values b e t w e e n m o r n i n g and evening trials. A f t e r r e c t a l a d m i n i s t r a t i o n , no s i g n i f i c a n t d i f f e r e n c e w a s d e m o n s t r a t e d in VPA k i n e t i c s b e t w e e n m o r n i n g and evening trials. Thus, the r e c t a l a d m i n i s t r a t i o n m i g h t h a v e an a d v a n t a g e to e l i m i n a t e t h e t i m e - d e p e n d e n t c h a n g e s of VPA k i n e t i c s . 9 School of P h a r m a c e u t i c a l S e i e n c e s , K i t a s a t o Univ. T o k y o , J a p a n 9 * D e p a r t m e n t of P h a r m a c o l o g y , E h i m e Univ.School of Medicine E h i m e - k e n , 791-02, J a p a n

Zaklad Farmakologii Klinioznej IMW W A M 90-451 ~6d~, ul. Kniaziewicza 1/5, Poland

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PLASMA HYDROCORTISONE SUPPRESSION AFTER DEXAMETHASONE ADMINISTRATION AT DIFFERENT TIMES OF DAY, ASSESSED WITH A PHARMACOKINETIC MODEL R.P. Koopmans, M.C.P. Braat, B. Oosterhuis, and C.J. van Boxtel The suppression of plasma hydrocortisone (HC) after dexamethasone (DEX) administration (0.5 mg iv) was investigated for DEX dosage times 08.00 h and 20.00 h. HC production after DEX administration was analysed by applying a pharmacokinetic model to the time course of plasma HC over a 24 h period following DEX. After DEX at 08.00 h HC production was instantaneously reduced to a minimum level, and HC rapidly disappeared from plasma with an elimination half-life of 1.32 • 0.28 h (mean • SD). Almost complete suppression of HC production lasted for 20 hours. The nocturnal increase in HC p r o d u c t i o n at 20 h after DEX administration was still attenuated compared to the preceding night. After DEX administration at 20.00 h plasma HC was lower than control for about 20 h, but it was not reduced to the minimum level observed after DEX dosage at 08.00 h. Approximately 20 hours after dosage of DEX at 20.00 h HC production seemed to follow the normal diurnal variation of the control values again. The present findings indicate that the hypothalamic-pituitary-adrenal axis exhibits a diurnal variation in its sensitivity to suppression by a small dose of dexamethasone, with greater sensitivity, and thus stronger suppression, after dosage in the morning. Clinical Pharmacology Section, Department of Internal Medicine, and Department of Pulmonology, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.

INFLUENCE OF THE MENSTRUALCYCLE ON THE ABSORPTION OF THE D-XYLOSE C. F i s e t , M. LeBel ~"e--e'rFect~menstrual cycle on D-xylose absorption was studied in 10 healthy female volunteers (mean age • SD: 24.0 • 2.9 years; mean body weight: 57.5 • 5.4 kg). D-xylose k i n e t i c s were determined a f t e r 25 g oral and 5 g intravenous administration on two successive days, during the f o l l i c u l a r , the ovulatory and the l u t e a l phases o f the menstrual cycle. D-xylose was assayed by c o l o r i m e t r i c analysis. Pharmacokinetic parameters a f t e r oral administration were determined by extended l e a s t squares (MKMODEL) and are displayed in the following table. Follicular Ovulatory Luteal F (%) 47.3 • 1 1 . 3 5TTI~T'~--I-~.8 54.--6-~-T5.4 Ka (H- i ) 0.9~ 0 . 6 2 0 . 8 7 • 0.34 0 . 9 4 • 0.35 TLag (H) 0.14• 0.6 0.16~ 0 . 1 0 0.12t 0.03 Cmax(ug/mL) 496.9 • 509.6• 439.8~101.0 Tmax (H) 1.6~ 0.52 1.42 0.59 1.45• 0.75 AUC(~g.H/mL) 1530 • 472 1713 • 451 1537 • 373 Vss (L/kg) O.4E 0.25 0.38 0.10 0 . 4 3 • 0.10 CL (mL/min) 306.2 • 261.6 • 8 0 . 7 285.6 • 67.7 t ~ (H) 0.95~ 0.15 1.0~ 0.37 1 . 0 ~ 0.16 p < 0.05 (ANOVA, repeated measure} These r e s u l t s could not show any s i g n i f i c a n t d i f f e r e n c e in the D-xylose pharmacokinetics during the menstrual cycle. Although, the Cmax value tends to be smaller during the luteal than the other phases, t h i s parameter does not reach s t a t i s t i c a l threshold (p = 0.07). It appears t h a t the hormonal changes during the menstrual cycle does not a f f e c t the absorption of D-xylose in normal healthy females. Ecole de Pharmacie, Universit~ Laval et Centre de Recherche, Centre H o s p i t a l i e r de l ' U n i v e r s i t ~ Laval, Quebec, Quebec, Canada, GIV 4G2.

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PP 05.07 DIURNAL VARIATIONS IN T H E ETHANOL IN Y O U N G A G E D M I C E S. M i n e s h i t a , H. S h i n o d a a n d

METABOLISM Y.

OF

Honda

Purpose of the study: This study was carried out to investigate whether diurnal variations exist in the metalolism of ehanol in young and aged mice. Materials and methods: Experiments were

performed w i t h 80 5 - w k s o l d a n d 60 25-wks old male ddy mice, which were adapted for at l e a s t 2 w k s to a 1 2 / 1 2 h l i g h t - d a r k cycle (with l i g h t f r o m 8 : 0 0 to 2 2 : 0 0 ) . Ethanol (l.0g/kg) was administered i.p. at either 9:00 or 2 1 : 0 0 . Serum samples were taken 20, 40, 60 a n d 80 m i n a f t e r t h e i n j e c t i o n . Ethanol concentrations were determined by m e a n s of f l u o r e s c e n c e immunoassay. Results: T h e s l o p e of t h e e t h a n o l (P<0.05) at 9 : 0 0 t h a n at 2 1 : 0 0 in y o u n g mice, but the difference w a s not s i g n i f i c a n t in a g e d mice. Comparison of the ethanol elimination curves showed that there was a significant slope reduction in a g e d mice compared to y o u n g m i c e . Conclusions: There exists a diurnal variation in the ethanol metabolism in young mice. In young mice that were a d a p t e d to l i g h t c y c l e of 8 : 0 0 to 22:00, ethanol was eliminated at a significantly faster rate when administered at 2 1 : 0 0 t h a n 9:00. The diurnal variation seemed to decrease with advancing age'.

STEREOSELECTIVE DISPOSITION AND GLUCURONIDATION OF CARVEDILOL IN HEALTHY SUBJECTS M_~.Fujimaki~ Y_~.Murakoshi~ and H. Hakusui Following oral dosing, the disposition of R(+)- and S (-)-carvedilol (C) and their glueuronides was studied in healthy subjects. Methods: Five healthy male subjects each reeieved 20 mg C with subsequent collection of plasma samples. Plasma concentrations of R(+)- and S(-)-C before and after enzymatic hydrolysis with B-glucuronidase were determined by a stereospecific HPLC assay. The pharmaeokinetic parameters between both enantiemers were compared for the evaluation. Results: After an oral administration of C, there was a significant difference in Cmax and AUC between two enantiomers. The mean Cmax and AUC for R(+)-C were 2.7 and 2.8-fold greater than those for S(-)-C, respectively. The ratios of Cmax and AUC for R(+)/S(-)-C glucurohides were 2.5 and 3.0, respectively. Plasma enantio ratio for glucuronide was similar to that for unchanged C. The systemic availability of S(-)-C was only 53% of that of R(+)-C, and the Cltot of S(-)-C was 1.4-fold greater than that of R(+)-C, whereas ti/2 values for both enantiomers were nearly identical. That was explained by the larger Vd for S(-)-C compared to R(+)C. Conclusion: The present study showed that the disposition of C is stereoselective in human and the difference between enantiomers must be mainly ascribed to a stereoselective first pass metabolism. The glucuronide conjugation pathway is demonstrated not to be related to such a stereoselective metabolism of C. Drug Metabolism Research Center, Research Institute, Daiichi Seiyaku Co, Ltd., 1-16-13, Kitakasai, Edogawa-ku, Tokyo 134, Japan.

Department of Social Medicine, Medical Research Insitute, No.3-10, 2-chome, Kandasurugadai, Chiyoda-ku, T o k y o , i01, J a p a n .

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PP 05.08 PHARMACOKINETICS, HEMODYNAMIC AND EFFECTS OF THE NITRENDIPINE ENANTIOMERS G.Mikue~ V.Mast, D.Rat.qe, H.Wisser~ M.Eichelbaum

BIOCHEMICAL

Nitrendipine is a calcium antagonist with dihydropyridine structure which has potent vasodilating properties. It is used clinically as a racemate containing (-)-S- and (+)-R-nitrendipine. The present study was undertaken to determine the pharmacokinetics, hemodynamic and biochemical effects of the nitreridipine enantiomers. Six healthy volunteers (3 female, 3 male) received on 5 different occasions placebo, 20 mg (-)-S-, 20 mg (+)-R-, 80 mg (+)-R- and 20 mg peeudoracemic (10 mg (-)-S- and 10 mg [13C4]-(+)-R- ) nitrendipine as a solution p.o.. Over the first 4 h blood pressure, heart rate, peripheral blood flow, plasma renin, adrenaline, noradrenaline, dopamine and aldosterone were measured. Serum nltrendlplne was determined up to 30 h using a GC-MS method. No effects on any pharmacodynamic or biochemical parameter were observed after placebo, 20 mg (+)-R- and 80 mg (+)-R-nitrendipine. After administration of 20 mg (-)-S-nitrendipine several biochemical parameters were influenced with the most pronounced effect- on pl~_=ma r_~nim. Significsmt reductions of blood pressure and peripheral vascular resistance were observed. The effects were less marked after 20 mg pseudoracemic nitrendipine. Nitrendipine serum levels showed pronounced interindividual variations. Calculated biovailability was 44.4 +_ 22.8 % (20 mg (-)-S) and 10.7 .- 7.4 % (20 mg (+)-R). After pseudoracemic administration biovailebility for (-)-S-nitrendipine was unchanged whereas that of the (+)-Risomer increased (22.1 _+ 11.9 %). Thus, nitrendipine exhibits stereoselective first pass metabolism with a possible interaction of the enantiomers when it is administered as a racemate. At therapeutic nitrendipine doses (-)-S*nitrendipine alone is responsible for the pharmacological effects observed. Supported by theRobert Bosch Foundation, Stuttgart. Dr. Margarete Fischer-Bosch-lnstitut f~ir Klinlsche Pharmakologie, Auerbachstr. 112, D-7000 Stuttgart 50 ] FRG.

THE INFLUENCE OF THE HYDROXYLATION PttENOTYPE ON THE PHARMACOKINETICS AND BETA 2 RECEPTOR PHARMACODYNAMICS OF METOPROLOL AND ITS ENANTIOMERS. R.E. J o n k e r s , R.P. K o o p m a n s a n d C.J. v a n Boxtel. The i n f l u e n c e o f t h e h y d r o x y l a t i o n p h e n o t y p e on t h e pharmacokinetics a n d p h a r m a c o d y n a m i c s of m e t o p r o l o l (METe) w a s i n v e s t i g a t e d in p o o r m e t a b o l i s e r s (PM) a n d e x t e n s i v e m e t a b o l i s e r s (EM) o f METe. P h a r m a c o k i n e t i c s w e r e analysed using classical compartmental models. Pharmacodynamics were compared using the antagonism by METe of b e t a 2 r e c e p t o r m e d i a t e d e f f e c t s ( t e r b u t a l i n e (TER) induced hypokalemia), by pharmacokinetic-pharmacodynamic m o d e l l i n g . T h e c o m p u t e r p r o g r a m NONLIN w a s u s e d f o r c u r v e fitting and modelling. Six h e a l t h y EM p h e n o t y p e s a n d 5 m a t c h i n g PM p h e n o t y p e s v o l u n t e r e d . EM r e c e i v e d 0.5 mg TER s.c. on two d i f f e r e n t o c c a s i o n s a t a b o u t 9 A.M.: 1. w i t h o u t p r e t r e a t m e n t 2. one h o u r a f t e r 150 mg METe p.o.. PM r e c e i v e d 0 . 7 5 rag TER s.c. on d a y 2. Blood s a m p l e s f o r a n a l y s i s of p l a s m a K+, METe ( t o t a l , R - a n d S - i s o m e r ) a n d a - O t i m e t o p r o l o l (a-OHMETO) concentrations were taken at regular time intervals during 8 h o u r s . C o n c e n t r a t i o n - t i m e c u r v e s of METe, c~-OHMETO a n d TER were fitted to the appropriate equations. P h a r m a c o d y n a m i c s of d a y 1. w e r e m o d e l l e d to a slgmoid E m a x model, t h o s e o f d a y 2. to a c o m p e t i t i v e i n t e r a c t i o n sigmoid E - m a x model. PM h a d h i g h e r METO/a-OHMETO a n d R / S - i s o m e r AUC r a t i o s a n d a l s o h i g h e r t o t a l METe IC50 v a l u e s c o m p a r e d to EM. When t h e c o n c e n t r a t i o n s of t h e a c t i v e S - i s o m e r , i n s t e a d of t h o s e of t o t a l METe, w e r e m o d e l l e d , a (small) d i f f e r e n c e in t h e ICS0 v a l u e s b e t w e e n EM a n d PM p e r s i s t e d . T h e r e w e r e significant correlations between several pharmacokinetic and p h a r m a c o d y n a m i c i n d i c e s . The p o s s i b i l i t y of b e t a 2 r e c e p t o r a n t a g o n i s m b y a - O H M E T O is s u g g e s t e d . A p p a r e n t d i f f e r e n c e s b e t w e e n PM a n d EM f o r t h e b e t a 2 r e c e p t o r a n t a g o n i s m b y METe, c a n be a t t r i b u t e d to d i f f e r e n c e s in METe d i s p o s i t i o n . C l i n i c a l P h a r m a c o l o g y S e c t i o n , A c a d e m i c Medical C e n t e r . M e l b e r g d r e e f 9, 1105 AZ A m s t e r d a m , T h e N e t h e r l a n d s .

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STEREOSELECTIVE SULFATE CONJUGATIONOF CHIRAL PHENOLIC AMINE DRUGSBY HUMANLIVER CYTOSOL. UK Walle and T Walle. In a previous in vivo study of the metabolism of propranoIoi in man i t appeared that the sulfate conjugation of i t s main metabolite 4-hydroxypropranolol (HOP) was stereoselect i v e , favoring the (+)-enantiomer about 4-fold. As stereo s e l e c t i v i t y in sulfation had not previously been reported for any chiral drug in man, we pursued this question i n v i t r o , using human l i v e r from LTPADS with racemic HOP as a model substrate. The preparation used was the l i v e r cytosol together with the cosubstrate PAP~SS. The enantiomers of i n t a c t HOP sulfate formed during incubations were separated and measured by chiral d e r i v a t i z a t i o n , HPLC and l i q uid s c i n t i l l a t i o n counting. Complex biphasic v e l o c i t y vs. substrate concentration (0.I-I000 pM) curves were observed with peak sulfation a c t i v i t i e s occurring at 3 ~M and 500 ~M HOP. The high a f f i n i t y reaction (3 ~M) produced a Kmapp of 1 ~M for 5oth enantiomers. The Vmaxapp was, however, 4-fold higher for the (+)-enantiomer, exactly as in vivo. The low a f f i n i t y reaction (500 ~M) produced a K m a ~ - ~ 3 2 ~M for both enantiomers, however, without any enan~1omeric difference in VmaXann. The pH dependency was similar for both s i t e s , demonstrating optimum a c t i v i t i e s at pH 9.0-9.5. Dichloronitrophenol was a potent i n h i b i t o r (ICs0
P H A R M A C O K I N E T I C S OF E0747 E N A N T I O M E R S IN M A N T. Seki, M, Shimomura. J. H a s e a a w a , T. K a ~ @ z a w a a n d N. M o r i s h i ~ @ E0747 is a n e w c l a s s Ic a n t i a r r h y t h m i c agent which is a r a c e m a t e and has one asymmetric c a r b o n atom. In s e v e r a l a n i m a l species, there w a s no n o t a b l e d i f f e r e n c e in in vitro p r o t e i n binding between the enantiomers. T h e in vitro p r o t e i n b i n d i n g o f t h e d - f o r m in h u m a n s e r u m was 98%, t h a t of t h e 1 - f o r m , 60%, a n d t h e ~ l - a c i d glyco-protein (AAG) b i n d i n g of t h e e n a n t i o m e r s was m a r k e d l y different. We s t u d i e d the e f f e c t of the protein binding difference between enantiomers on t h e p h a r m a c o k i n e t i c s of o r a l E0747 in h e a l t h y volunteers. M e t h o d s : P l a s m a a n d u r i n e samples w e r e c o l l e c t e d after oral administration of the r a c e m a t e to healthy male volunteers. U s i n g H P L C m e t h o d , we determined the enantiomers of E 0 7 4 7 in p l a s m a a n d urine, a n d a m e t a b o l i t e (-COOH) in urine. We measured plasma AAG levels, plasma protein binding and electrocardiographic parameters. Results: The d - f o r m p l a s m a l e v e l for s e v e r a l h o u r s a f t e r E 0 7 4 7 o r a l a d m i n i s t r a t i o n was a b o u t 20 t i m e s h i g h e r t h a n t h a t of the 1-form. U r i n a r y e x c r e t i o n s of u n c h a n g e d e n a n t i o m e r s were 20% (dform) and 9% (1-form), and those of the metabolite (-COOH) w e r e 2% a n d 9%. T h e m e a n p l a s m a h a l f - l i v e s of t h e e n a n t i o m e r s w e r e 11.7 hours (d-form) and 5.5 h o u r s (l-form) . T h e p l a s m a p r o t e i n b i n d i n g of the r a c e m a t e was 96%, and there was a relationship between Cmax and AAG concentrations. Conclusion: T h e r e was a s i g n i f i c a n t d i f f e r e n c e b e t w e e n p l a s m a levels of the e n a n t i o m e r s in man, that was p r e d i c t e d f r o m the d i f f e r e n c e in the in vitro p r o t e i n binding. D i v i s i o n of R e s e a r c h a n d D e v e l o p m e n t , E i s a i Co., Ltd., K o i s h i k a w a 4, Bunkyo-ku, T o k y o 112, J a p a n

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MODELS OF HEPATIC ELIMINATION: IMPLICATIONS FROM STUDIES OF THE SIMULTANEOUS ELIMINATION OF TAUROCHOLATE (TC) AND DIAZEPAM (DZ) UNDER VARYING CONDITIONS OF BINDING M. S. Ching, D. J. Morgan and R. A. Smallwood Various kinetic models have been developed to describe the elimination of substances by the liver, but there is no agreement about which is "the correct" model, since experimental evaluation is incomplete and results conflict. We have shown (J. Pharm. Biopharm. 16, 377, 1988) that TC elimination is best described by models that embody a--high degree of sinusoidal heterogeneity or mixing, while another study (J. Pharm. Biopharm. 12, 129, 1984) showed that DZ elimination is best described by models that embody a low degree of sinusoidal heterogeneity or mixing. To investigate this discrepancy we examined, in the isolated perfused rat liver, the simultaneous elimination of TC and DZ. The effect on hepatic availability of varying unbound fraction ( f ) in a single pass, steady state system (perfusate flow ~6 ml/min) was studied in 6 livers for TC (fu 0.066-0.966) and DZ (f 0.051-0.675) by varying perfusate albumin concentration ~0-60 g/l). As before, elimination was better described by the venous equilibrium model and dispersion model with a high dispersion number (DN = ~ ) (well-mixed models) for TC, and the undistributed sinusoidal model and dispersion model with a low dispersion number (DN = 1.04) (unmixed models) for DZ. A third model, a distrlbuted model incorporating heterogeneity of sinusoidal blood flows and intrinsic~clearances, fitted the data for both TC and HZ. The fitted coefficients of variation of both flow (cv') and intrinsic clearance (cv'') were large for TC (176, 164, respectively), but for DZ ev' was large (200) while cv'' was small (0.807). We conclude that the difference between TC and DZ kinetics is not due to differences in transverse heterogeneity of sinusoidal blood flow, but can be accounted for by differences in transverse heterogeneity of sinusoidal intrinsic clearance. Our results provide a conceptually plausible and operationally accurate description of hepatic elimination kinetics. Dept. of Medicine, Austin Hospital, Melbourne 3084~ and Victorian College of Pharmacy, Melbourne 3052, Australia.

ENANTIOSELECTIVITY OF E-10-HYDROXYNORTRIPTYLINE GLUCURONIDATION IN MAN, IN V I V O A N D IN V I T R O E. D u m o n t , M.L. D a h l - P u u s t i n e n a n d L. B e r t i l s s o n E-10-hydroxynortriptyline (E-10-OK-NT) is the m a j o r m e t a b o l i t e of n o r t r i p t y i i n e . E - 1 0 - O H - N T is a p o t e n t i n h i b i t o r of n o r a d r e n a l i n e u p t a k e and h a s v e r y l i t t l e a n t i c h e l i n e r g i c e f f e c t . It m i g h t b e c o m e an a n t i d e p r e s s a n t d r u g b y itself. The disposition of racemic E-10-OH-NT hydrogen m a l e a t e w a s s t u d i e d a f t e r a 75 m g o r a l d o s e to i0 h e a l t h y s u b j e c t s . C o n c e n t r a t i o n s of the enantiomers and their glucuronides were determ i n e d in p l a s m a a n d u r i n e b y H P L C a n d m a s s f r a g m e n t o g r a p h y . T h e p l a s m a c o n c e n t r a t i o n s of the ( - ) - e n a n t i o m e r w e r e 2-5 t i m e s h i g h e r t h a n t h o s e of ( + ) - E - 1 0 - O H - N T . O f the a d m i n i s t e r e d ( + ) - E , 1 0 - O H - N T dose, 64 + 12% w a s r e c o v e r e d as g l u c u r o n i d e a n d 14 + 5% as u n c h a n g e d c o m p o u n d . Glucuronidation (35--~ 10%) a n d r e n a l e l i m i n a t i o n of u n c h a n g e d c o m p o u n d (36 + 10%) w e r e e q u a l l y i m p o r t a n t for ( - ) - E - 1 0 - O H - N T . T h e r e n a l c l e a r a n c e of u n b o u n d ( - ) - E - 1 0 - O H - N T e x c e e d e d t h a t of t h e ( + ) - e n a n t i o m e r (p<0.005), a n d an enantioselective tubular secretion was suggested. G l u c u r o n i d a t i o n of ( ~ ) - E - 1 0 - O H - N T w a s s t u d i e d in v a r i o u s h u m a n o r g a n s in vitro. I n c u b a t i o n s w i t h l i v e r a n d k i d n e y h o m o g e n a t e s r e s u l t e d in t h e f o r m a t i o n o f t h e g l u c u r o n i d e o f (+)-, b u t n o t of ( - ) - E - 1 0 - O H - N T . In c o n t r a s t , h u m a n i n t e s t i n a l m u c o s a c a t a l y z e d the g l u c u r o n i d a t i o n of ( - ) - E - 1 0 - O H - N T , b u t n o t of the ( + ) - e n a n t i o mer. I n c u b a t i o n s of the s a m e o r g a n s w i t h the p u r i f i e d e n a n t i o m e r s c o n f i r m e d t h e p r e s e n c e of organspecific enantioselective glucuronosylt r a n s f e r a s e s in h u m a n s . D e p a r t m e n t of C l i n i c a l P h a r m a c o l o g y , K a r o l i n s k a Institute, Huddinge University Hospital, S-141 86 H u d d i n g e , S w e d e n

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STEREOSELECTIVE KINETICS AND DYNAMICS OF FENFLURAMINE ENANTIOMERS R.P. Richards, D. Taylor, S. Garattini, D. B Campbell Only recently, with the development of new analytical techniques, has the importance of stereoselective kinetics of drugs with chiral centresbeen more fully investigated. Racemic fenfluramine has been used for many years for the treatment of obesity, but now it has been shown that the eudismic ratio, the relative effectiveness of a reduction in food intake, is 2 times greater for the (+) enantiomer than for the (-) enantiomer in animals and with no activity of the (-) enantiomerin man. Although the(-) form does not alter the kinetics of the (+) form, when administered together there is a stereoselective preference for the metabolism of the (+) form in man. The radioactive (14C) enantiomers of fenfluramine (30rag) have been administered to 2 healthy volunteers and body fluids taken for the measurement of plasma kinetics and urinary metabolites. Maximum plasma levels (100ng equiv.ml-1) are similar for both enantiomers, but the half-life of radioactivity of the (+) form is faster (tr than the (-) form (tr Although the metabolic pathways are the same for both :forms, there is less { + ) fenfluramine (9% of dose) in the urine than the (-) form (13%). The same is true for norfenfluramine and the de-ethylated metabolite, (6 and 8% respectively), whilst for all further metabolites formed by oxidative deamination this ratio is reversed. This suggests that there is a stereoselectivity of the oxidative deamination metabolism of fenfluramine and not de-ethyJation. This stereoselectivity was further confirmed in 8 volunteers administered the enantiomers for 15 days (30mg daily). Steady state levels of fenfluramine achieved after 8 days were approximately 1.7 times higher for (-) fenfluramine (50ng.ml-1) compared to the ( + ) form and the terminal half-lives of unchanged drug were 25h and 18h respectively. Since (-) fenfluramine is inactive on food intake, but does elicit side effects, the clinical use of the (+) enantiomer alone has led to the development of a new, more acceptable treatment for the obese patient. Servier Research & Development Ltd., Fulmer, Slough, Bucks, SL3 6HH.

THE PHARMACOKINETIC$ OF IBUPROFEN ENANTIOMER$ IN MAN

It has only recently become obvious that the optical isomers of chiral xenobiotics are handled bY atereoselective processes during absorption, metabolisation and excretion. The resulting pharmacokinetic differences are of putative therapeutic relevance. Therefore, we studied ibuprofen, a nonsteroidal antiinf]ammatory drug, belonging to the group of 2-arylpropionic acids which exist as 8(+)- and R{-)- enantiomers. The racemic mixture of this drug is currently one of the most ~idely used antiinflamaatory

analgesics.

In man, there is only l i t t l e

conversion of the

pharmacotherapeutically inactive R(-]-isomer to the active S(+)isomer. Consequently, i t appears of potential c l i n i c a l advantage to employ the $(+)-isomer only, particularly since i t would allow for reduction of the drug load to the human body without losing much therapeutic a c t i v i t y . In order to obtain proof for this contention, we analysed the f u l l pharmacokinetic behaviour of both isomers being given either alone or as racemate in 11 volunteers over a dose 2-a~ge of 150-500 mg ibuprofen (single dose). It turned out that the conversion of R{-)ibuprofen after raoommte administration in man calculated from tha AUC is approx, one third, moreover, we found that S[+)ibuprofen given alone reaches high plasma concentrations faster than either R(-)-ibuprofen alone or ibuprofen given in a racemic mixture. I n addition, in a double-blind controlled study, we found that 1,2 - 1,6 g/day $(+)-ibuprofen were as effective as 1,8 - 2,~ g/day ibuprofen racemate. We conclude, that S(m]-ibuprofen given alone may be advantageous because a) the metabolic load to the human body is reduced b} peak plmmma concentrations and, by that, probably pain-relief is reached faster and c) patients are more l i k e l y to comply when dosed with 1,2 - 1,6 g/day am compared to 1,8 - 2,~ g/day of drug. Institute of Pharmacology, University Univermitaetsstr. 22, 0-8520 Erlangen, FRG.

of

Erlangen,

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$TEREOSELECTIVE DISPOSITION OF MORPHINANS WITH A QUATERNARY AMMONIUM CROUP, STUDIED WITH THE ISOLATED PERFUSED RAT LIVER. A.B.L. Lanting, D.K.F. Mailer, R.A. de Zeeuw, B.F.H. Drenth Enantiomers of morphinans show large differences in pharmacological properties: only the l-isomer of levorphanol is used as an analgesic, and the d-isomer, dextrorphan, is not. Considering these large differences between enantiomers on the receptor-level, differences in interaction with metabolizing and/or transporting proteins are in principle possible. The morphinaniums have a permanent positive charge. Specific properties are e.g. virtually no transport across the blood-brain barrier, but extensive carriermediated transport in various organs in the body. We have previously shown that quaternizing the tertiary amine function of morphinans does not affect the stereospecificity in receptor interaction in guinea-pig ileum. We examined the pharmacokinetic behavior of the. radioactively labelled, enantiomers N-methyldextrorphan (NMD) and Nmethyllevorphanol (NML) in the isolated perfused rat liver. Quantitation in bile and perfusate was done by liquid scintillation counting. Bile and perfusate samples were also analysed by TLC and by HPLC. to establish a metabolic profile for the enantiomers. The morphinaniums and metabolites were detected by on line fluorescence spectraphotometry and by off line radioactivity counting. Preliminary results show differences in half life of plasma disappearance for the parent compounds NML and NMD. The maximal biliary excretion rate was 9 . 1 n m o l / m i n for NML and 16.6 nmol/min for NMD. The total amount excreted in bile was 50% of dose for NMD and 38.5% of dose for NML. Gonjugation with glueuronie acid and sulphate appears to be the maj or metabolic pathway for these morphinaniums. A small amount of other metabolites with intermediate polarity could he detected. So stereoselectivity occurs not only in interaction with receptors ~ u t also in hepatic disposition of the morphinaniums. University of Groningen, Centre for Pharmacy, A Deusinglaan 2. 9713 AW Groningen, The Netherlands

PHARMACOKINETIC PROFILE OF ALFUZOSINE ENANTIOMERS IN HEALTHY VOLUNTEERS AFTER AN INTRAVENOUS ADMINISTRATION OF RACEMIC ALFUZOSINE 9 A. Rouchouse F A. Durandq J.P. Th~not and P.L. Morsel li Alfuzosine (XatralM), a ~l-adrenoceptor antagonist, recently introduced in therapeutics for the treatment of the benign prostate hypertrophy, is a racemate. A direct liquid chromatographic method was developed for the determination of its enantiomers in plasma, using a chiral ~l-acid glycoprotein second generation column and applied for the evaluation of the pharmacokinetic profile of alfuzosine enantiomers in healthy volunteers after one single intravenous dose (5 mg) of racemic alfuzosine. The enantiomers and their internal standard, structuraly related to alfuzosine, were extracted from plasma with a mixture dichloromethane/diethyl ether under basic conditions (pH 12). They were eluted by a mixture phosphate buffer 0.025M + T B A 0.025 M (pH 7.4) acetonitrile (94/6, v/v). Fluorometric detection allowed the quantification of alfuzosine enantiomers down to I ng.ml -I. Both isomers were eliminated from the central compartment according to a triphasic process with terminal elimination half-lives of about 3.6 + 0.6 hours and 2.5 + 0.3 hours for the R and S enant~omer, respectively. Although this difference between the R and S isomer kinetics is significant, it might b e of no clinical relevance since, the experiments conducted in the rabbit demonstrated that the pharmacological activity of the (R) and (S) enantiomers is identical. Synth~labo Recherche (L.E.R.S.) Clinical Research Department, 58 rue de la Glaciate 750]3 Paris FRANCE -

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EFFECTS OF AGE ON THE PROTEIN BINDING AND APPARENT AFFINITY OF I-PROPRANOLOL FOR CARDIAC BETA-RECEPTORS R.L. Lalonde, D.M. Tenero, V.L. Herrinm. M.B. Bottorff There are stereoselective differences in the receptor affinity, pharmacokinetics and protein binding of propranolol enantiomers. However, previous studies have failed to account for enantiomeric differences in serum concentrations and p~otein binding of propranolol in the determination of the sensitivity of cardiac betareceptors in vivo. We studied 1O young (28 • 3.3 y.o.) and i0 elderly (64 i 7.5 y.o.) healthy nonsmoking men. The dose of isoproterenol (short bolus) required to increase resting heart rate by 25 bpm was determined before and during an intravenous infusion of racemic propranolol. The serunl concentrations of each enantiomer were determined by HPLC and the unbound fraction of the pharmacologically active l-propranolol was measured by equilibrium dialysis. Data are reported as the median (range). The apparent receptor dissociation constant for unbound l-propranolol (Kd-free) increased from 0.049 ng/ml (0.017 - 0.18) in the young to 0.13 ng/ml (0.0700.95) in the elderly (p<0.01). The unbound fraction of lpropranolol (fu) decreased from 0.15 (0.ii - 0.18) in the young to 0.12 (0.09 - 0.16) in the elderly (p<0L05). There was a significant correlation (r=0.46) between age and Kd-free (pi00 fold variability in the dissociation constant measured in terms of total (bound+unbound) l-propranolol (Kd-total). With the removal of the 2 fold variability in fu, the resulting overall variability in Kd-free was reduced to 55 fold. We conclude: i) advancing age is associated with a decrease in apparent receptor sensitivity to propranolol; 2) given a total serum Concentration of lpropranolol, the large variability in pharmacologic effect is due mainly to variability in Kd-free and. to a lesser extent, to differences in protein binding. Department of Clinical Pharmacy, 26 South Dunlap St @202 University of Tennessee, Memphis, TN, 38163

A CIRCULATORY LAG MODEL FOR AN OSCILLATION IN THE THIOPENTAL CONCENTRATION-TIME CURVE T.K. Henthorn, M.J. Avram, T.C. Krejcie & C.A. Shanks We have reported the pharmacokinetics (PK) of IV thiopental (TP) in 12 patients; frequent early arterial blood sampling focused on early drug disposition I (In 8 subjects, a single oscillation in TP plasma concentrations was observed 4.5 to i0 minutes after its injection. Standard PK models cannot account for fluctuations in the plasma concentration-time curve). ~ A similar secondary peak was not seen in the curve for indocyanine green (ICG) administered simultaneously. We hypothesize that these findings can be characterized by adding a lag function to a peripheral intercompartmental rate constant. METHODS: The 12 hr. plasma concentration-time data 1 following IV injection of TP, 3 mg/kg, and ICG, 0.5 mg/kg, were reanalyzed. A peripheral compartment was added to the model, incorporating a lag function which delayed drug return from it to the central compartment. RESULTS: To best model the secondary peak in TP concentrations, this additional compartment requires: (a) a lag time of approximately 3 min, (b) a distribution volume of approximately 5 L for TP and 1 L for ICG, (c) an intercompartmental clearance of 1.5 L/min for both TP and ICG and (d) elimination occurring from it. Minor variations in items (a)-(c) result in an unapparent secondary TP peak. DISCUSSION: The new model can account for the oscillation observable in the TP plasma concentration-time curve following IV bolus injection. The additional peripheral compartment is probably related to the portal circulatinn, a languid part of the vasculature. 2 Elimination of both agents occurs in the liver. The lack of oscillation in the ICG curvereflects its greater hepatic extraction. REFERENCES: iHenthorn TK, et al: Clin Pharmaeol Ther 45:56-65, 1989. 2Green JF: Am J Physiol 232:HI52-HI56, 1977. Department of Anesthesia, Northwestern University, Chicago, IL 60611, USA

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STEREOSELECTIVE P H A R M A C O K I N E T I C S OF MK-927, A NOVEL TOPICAL C A R B O N I C A N H Y D R A S E I N H I B I T O R F O L L O W I N G O C U L A R AIIMINISTRATION. J Biollaz~ EA Lippa~ T Baclin~ G WinchelltBK Matuszewski A Munafe t M Piquet t F Brunner-Ferber~ JL Schelling. ~(-927, a novel c a r b o n i c a n h y d r a s e i n h i b i t o r (CAI) designed for t o p i c a l ocular a d m i n i s t r a t i o n , lowers intraoeular p r e s s u r e in patients, Three drops of 2% M K 927 s o l u t i o n w e r e i n s t i l l e d in b o t h eyes of 7 h e a l t h y subjects o v e r 2 m i n u t e s ( t o t a l dose: 3.9+0.3 rag). Concentrations of MK-927 (raeemic) and of its [ enantiomers were determined over 14 days in plasma~ whole blood and urine using stereoselective HPLC assay methodology (R and S d e t e c t i o n l i m i t of 12.5 ng/ml). C o m p e n s a t i n g for overflow and tearing (paper tissue colleetion)~ the effective dose a d m i n i s t e r e d ranged f r o m 0.8 to 3.1 m g (median 2.3 rag). P l a s m a levels w e r e a l w a y s less t h a n 2% of whole blood levels and only the R-isomer was detected in urine. The t i m e to 50% a b s o r p t i o n s and T 89 w e r e 0.24 vs 0.57 h and 5.4 vs 300 h for R- vs S-isomer~ r e s p e c tively (all at p
USE OF A PHARMACOKINETIC MODEL TO PREDICT STEADY STATE PHENOBARBITONE LEVELS M__L. Fesly, S. Kumar, S. Peaker, H. Chryatyn , P. Rice and T. Pullar We have attempted to improve the accuracy of the technique of assessing compliance using low-dose phenobarbitone (PB), as a pharmacological indicator (Feely et sl, Br. J. olin. Pharmac. 24, 77, 1987). In s previous study, pharmacokinetie data from 10 healthy volunteers was used to derive a model to predict steady state PB levels from measurements after a single dose, using Bayesian analysis (Kumar et al, Br. J. olin. Pharmsc. 1988, in press). We have now tested this model in 8 (other) healthy volunteers (6 males, 2 Females; aged 25 to 43 yrs). Each subject was given PB 8 mg as a single dose and, after an interval of 96 hrs, PB 2 mg daily for 28 days. Blood samples were taken at intervals of 24, 48, 72 and 96 hrs post single dose and pre-dose and st I, 6 and 24 hrs following the last of the repeated doses. Plasma PB levels were measured using HPLC. Predictions of steady state peak and trough PB levels were made from single PB measurements st 24, 48, 72 and 96 hrs Following the single dose, using the previously derived pharmacokinetie model. The 96 hr post single dose PB level gave the most precise prediction of steady state peak (shown in table) and trough PB levels (root mean squared error of 26.8 and 38.0 respectively).

Div. of C l i n i c a l P h a r m a c o l o g y , U n i v e r s i t y Bospital~ Lausanne, Switzerland and MSDRL, West Poinb, PA, USA.

Subject No

1

Steady s t a t e PB levels Measured (ng/ml) 386 Predicted (ng/ml) 390

2

]

4

5

6

7

8

453 460

355 410

365 390

255 250

413 430

398 386

361 331

Steady state PB levels can be predicted from one measurement at a timed interval following a single dose; this may allow more accurate detection of incomplete compliance. Clinical Pharmacology Unit, The General Infirmary, Leeds, LSI 3EX, and School of Pharmacy, University of Bradford, Bradford, BD7 IDP, UK.

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USE OF A PHARMACOK1NETIC-DYNAMIC MODEL FOR AUTOMATIC FEEDBACK CONTROL OF ATRACURIUM K. T. Olkkola and H. Schwilden Pharmacokinetic-dynamic modeling provides a useful tool for determining dosing regimen for particular time requirements. The applicability of model-based adaptive feedback control of atracurium (ATR) administration during anesthesia was studied in eight surgical patients. Pharmacokinetics of ATR was described by a two-compartment open model where the central compartment was connected to an effect compartment (biophase). Sigmold Emax model was used to describe drug effect as a function of effect compartment concentration. Muscle relaxation was measured using Datex Relaxograph ~ NMT-monitor. Depending on the discrepancy between model-based theoretical effect and measured effect, parameters of the kinetic model were adjusted in order to minimize the discrepancy. Anesthesia was induced with thiopentone and maintained with the use of 60 % N20 in O v Fentanyl and flunitrazepam were used to supplement anesthesia as required. All patients were given a bolus dose of ATK. ."!~..e setpoint for muscle paralysis was set to 10 ..~ of control. Automatic feedback control of muscle relaxation was initiated as soon as the setpoint was reached for the first time after ATr~ administration. Mean (-+ SD) feedback time was 129 -+ 67 min. Offset from setpoint was 0.04 +_ 0.46 % and standard deviation from mean 1.85 _+ 0.63 % during feedback. Based on a nonlinear regression model (cumulative ATR dose = D*[1-ek'ti~]+ Ratess*time), mean ~,Trt requirement in steady state was 0.37 _+ 0.10 m g / k g / h . Accordingly, model-based adaptive closed-loop control of ATR infusion provided excellent control of muscle relaxation which guaranteed good operative conditions and fast postoperative recovery of the neuromuscular junction. This approach gives a solution to the problem of adapting pharmaeokinetic and pharmacodynamic data to individuals when using mean data as starting values for drug therapy. Department of Clinical Pharmacology, University of Helsinki, Paasikivenkatu 4, SF-00250 Helsinki, Finland

DOES THE RESPONSE OF THE HUMAN SKIN TO INTRACUTANEOUSLY APPLIED HISTAMINE REALLY DEPEND ON THE TIME OF APPLICATION? D. Rehn*, H.Gei~ler 2, U. Sch6nbrunn 2, H.Lukas 2, and

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once a day - a d o s e - e f f e c t - r e l a t i o n

Fenistil

I . Andresen l , D. Rehnl , H. Lukas 2 R

F e n i s t i l once a day is a new sustained release form of dimetindene maleate known as a classical Hi-antagonist of high potency. From t h i s g a l e n i c a l f o r m u l a t i o n dimetindene maleate is l i n e a r l y l i b e r a t e d reaching more than 90 % l i b e r a ' t i o n a f t e r 14 hours. In order to explore the d o s e - e f f e c t - r e l a t i o n the reduction of histamine-induced weal and f l a r e reactions (the r a t e , the extent and the duration of the e f f e c t ) was i n v e s t i g a t e d . The provocation was performed by intracutaneous i n j e c t i o n s of 0.05 ml of a I0- % aqueous histamine s o l u t i o n . All 3 d i f f e r e n t doses of FOAD (2, 4, 6 mg dimetindene maleate) were separately i n v e s t i g a t e d versus placebo by using a two-period cross over study design. ~iaximal i n h i b i t i o n of the histamine-induced f l a r e s was observed at the 4th and 5th provocation i . e . 14 and 17 hours a f t e r a p p l i c a t i o n of FOAD. The weal and f l a r e areas recorded at 5, I 0 , 20 and 30 minutes a f t e r provocation were t r a n s f e r r e d i n t o i n t r i n s i c area under the curve (AUC) values using the trapezoidal rule. The log AUC 0.05 - 0.30 at the time of maximal e f f e c t s were 3.64 (FOAD 2 mg), 3.70 (FOAD 4 mg), and 3.37 (FOAD 6 mg) as compared to pretreatment values of 4.14, 4.24, 4.13 and to placebo treatment values of 4.04, 4.14: 3.96. I) Zyma GmbH, Hauptabteilung Medizinische Entwicklung, Z i e l s t a t t s t r a ~ e 40, 8000 MUnchen 70; 2) PAZ GmbH, In der Schildwacht 13, 6230 Frankfurt 80.

G. HenningsX The intracuteneous histamine application is a suitable provocation model for investigating the E, - antagonistic effects of potentially antiallergic drugs. Previous investigations of Reinberg et al, suggest a circadiane rythm of skin sensitivity to histamine provocations (A. Reinberg, et al., Chronopharmacological study of antihistamines in man with special reference to terfenadine, Eur.J.Clin.Pharmacol.,14, 245-252, 1978). In order to investigate the effectkinetic profile of dimethindene maleate (Fenistil R ) it was necessary to collect more detailed information about potential circadiane influences. 8 male healthy volunteers were treated with placebo in various formulations (i.v., p.o. solution, p.o. capsules). Histamine solution was intracutaneously injected at time -i, 2, 5, 14, 17, 20, 23, 26, and 29 [hi. Weal and flare reactions were recorded 5, I0, 20, and 30 [min] following the histamine injections. Provocation time specific area under the reaction/time curve were calculated according the trapezoidal rule. The resulting AUCs-so [ml,] are log normal distributed. Medians of log AUC are between 3.945 and 4.24, 3.636 and 4.3, and 3.964 and 4.206 following 3 different capsules for p.o.-administration. Respective values for p.o. solution are 3.921 and 4.082. I.v. injection results in median log AUC values between 4.18 and 4.418. There is no indication in the available set of data for a circadiane dependance of skin reactivity to histamine injections, neither in the criterion weals nor flares. Also saisonal changes (the trials using 5 different placebo formulations were carried out in a period of 2 years) could not be detected. i) Zyma GmbH, Hauptahteilung Medizinische Entwieklung Zielstattstra~e 40, 8000 Mfinchen 70; 2) PAZ GmhH, In der Schildwaeht 13, 6230 Frankfurt 80.

KINETIC-DYNAMIC MODELING OF TERBUTALINE INDUCED SMALL AND LARGE AIRWAY RESPONSES, AND PLASMA POTASSIUM CHANGES IN ASTHMA PATI EArlS. FL C.P. Braat, P~ E. Jonkers, C.J. van Boxtel. Clinical 'Pharmacology Section and Department of Pulmonology, Academic Medical Centre, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands. We compared the concentration-effect relationships of terbutaline induced responses of Small and large airways and systemic (potassium) effects in asthma patients (AP) in stable conditio~ Seven AP, 3 females and 4 males, age 19-46, received a 0. 01 mg/kgbw s.c. dose o f terbutaline at about 9 k 5%. Plasma terbutaline and potassium concentrations, and lung function parameters of small (FEF50) , larger (FEVI) and large (PEF) airways, were monitored during 7 hours. Maximum achievable lungfunction (Emax) was established at t = 7 hours, after beta 2 mimetic nebulizatiorL Baseline (EO) as well as maximum (Emax) lungfunction, expressed as % predicted, were dependent on the function parameter employed, with mean Emax values of 66 +- 19 %, 96 -+ 18 % and 123 -+ 20 % for FEF50, FEV 1 and PEF ~esp., ar~ showed a strong negative correlation with age. The apparent beta 2 receptor affinity constant of terbutaline (EC50), was higher for PEF (4. 81 + 0. 83) than for FEV 1 (3. 84 -+ 1.08) (N.S.) and FEF50 (3. 69 + 0.68) (p=0. 05). EC50 for the potassium response was 4. 25 + I. 44; There was no consistent relationship between the pharmacodynamics of the potassium response and those of lungfunction within the group of AP. There was however an apparent difference in the potassium Emax and EC50 parameters between the AP and a group of 11 healthy s ubj ects. In conclusion, using kinetic-dynamic modeling, we were able to show differences in the beta 2 receptor mediated response of large and small airways in AP, and possibly differences in the beta 2 receptor dynamics between asthma patients and Healthy subjects.

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COMPARISON OF A PHYSIOLOGICAL PHARMACOKINETIC-PHARMACODYNAMIC MODELWITH AN EFFECTCOMPARTMENTMODELDESCRIBING THE HYPOKALAEMIC EFFECT OF TERBUTALINZ WITH AND WITHOUT METOPROLOL R,E. Jonkers, C.J. van Boxtel and N.H.G. Holford The hypokalaemic effect of terbutaline 0,5-07 mg s.c. was studied in healthy volunteers. Studies were performed with and without the administration of metoprolol 150 mg p.o. 1 hour previously~ Terbutaline and metoprolol were measured by HPLC and plasma potassium by flame photometry, The time course of terbutaline and metoprolol concentrations were describable by compartmental models. The time course of potassium was describable by an effect compartment model linking drug concentrations to effect with a sigmoid Emax model. The mean pharmacokinetic and pharmacodynamic parameters from the individual subjects were used to simulate data with typical experimental error. These simulated data were describable equally well by the effect compartment model (EC) (used to generate them) and a physiological kinetic model (PHK). The effect compartment e x i t rate constant estimated from the simulated data using EC was 7 h- I . PHK predicted an elimination rate constant for potassium of 5.8 h-l. Other model predictions were: Emax 3.0 (EC) and 1.45 (PHK) mmol/L; EC50 13.6 (EC) and 20.4 (PHK) ug/L terbutaline; KI 52 (EC) and 51 (PHK) ug/L metoprolol. Dept. Pharmacology & Clinical Pharmacology, University of Auckland, Private Bag, New Zealand.

P R E D I C T I O N O F DIGOXIN P L A S M A LEVELS IN R E P E A T E D DOSE REGIMEN BY A COMPARTMENTAL MODEL OF THE F I R S T 24 H O U R P L A S M A A N D U R I N E K I N E T I C S

.~.,__~:~...n-~hi,.....G....~....~...e.g~g,._-q..,..b_T~.~ The purpose of this w o r k is to ascertain whether it is possible to predict the values of plasma digoxin concentration following the initial administration by using only the first 24 hour kinetics. 22 patients with heart failure received the 0ral initial dose of 1 m g of digoxln; a dose of 0.5 or 0.25 m g was administered for m a n y following days. Plasma values were determined at 0.5, i, 1.5, 2, 3, 4, 8, B, i0, 12, 24 hours a n d at least twice for each of the following days. Urine levels were determined within 24 hours. T h e following compartmental model w a s formulated to describe the first 24 hour kinetics:

compartment

1=

drug

in

gastrointestinal

tract;

compartment 2= plasma compartment; compartment 3 = extravascular compartment; compartment 4 =urine; @ = delay in hour; k~= transfer constants (h-I) from eomp. i to comp.j; 9 =site of dose administration. The above model was solved by digital computing techniques a n d used to simulate the digoxin plasma kinetics for m a n y days. In most cases the calculated prediction was in agreement with the experimental values. Istituto di Farmacologia, Universit~ Scotte 6, 53100 Siena, Italy

di Siena,

Via

delle

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THE USE OF KINETIC-DYNAMIC INTERACTIONS OF ALMITRINE TO UNDERSTAND THE NEURONAL FEEDBACK REGULATION IN THE CONTROL OF RESPIRATION D.B. Campbell, Y. E v r a r d , B.H. Gordon, D.S. McQueen Almitrine bismesylate improves blood oxygen in patients with chronic obstructive lung disease (COLD) by stimulating the carotid body and improving ventilation perfusion mismatching in the lung. Following, single intravenous infusions to patients ( 0 . 5 m g . k g - ' over 30 rain) the relationship o f plasma levels to the increase, in blood oxygen showed a clockwise hysteresis suggestive of tolerance, inhibitory metabolites or feedback regulation. Similarly, following 3 months oral d r u g treatment (50rag b . i . d ) to COLD patients (n=32), a bell shaped relationship between the drug levels and activity was found with the h i g h e r plasma l e v e l s (>800ng.ml-1) r e d u c i n g t h e e x p e c t e d t h e r a p e u t i c r e s p o n s e . To gain an u n d e r s t a n d i n g of t he mechanism of action involved in t h e s e f i n d i n g s , animal s t u d i e s were u n d e r t a k e n in the r a t , dog and cat. These have shown r e s p e c t i v e l y t h a t almitrine does not p r o d u c e (a) t a c h y p h y l a x i s or t o l e r a n c e , (b) the major c i r c u l a t i n g metabolites are n e i t h e r a g o n i s t i c nor a n t a g o n i s t i c b u t (c) t h a t almitrine a c t i v a t e s a feedback i n h i b i t o r y p a t hw a y via the ganglioglomerula s y m p a t h e t i c autonomic n e r v e s and to a lesser extent the contralateral carotid nerve, thereby modulating carotid body stimulation of the carotid sinus. Thus, unexpected clinical kinetic dynamic interactions have lead to the design of pharmacological studies which, in t u r n , have provided us with a greater knowledge of the possible mechanisms controlling breathing. Servier Research & Development Ltd, Fulmer Hall, Windmill Road, Fulmer, Slough SL3 6HH, UK.

PHARMACOKINETICS OF R E C T A L M E T O C L O P R A M I D E (MCL) A N D PHARMACODYNAMICS OF TWO HIGH ANTIEMETIC RECTAL DOSAGES OF M C L A G A I N S T D I F F E R E N T E M E T I C DOSES OF C I S P L A T I N (CIS) F O R C H E M O T H E R A P Y A.Hellstern, R.Saller, D.Hellenbrecht, M.Haug, G.Achtert*, P.Brockmann*, W . D a h m e n * Lower (50-<90 m g / m 2) and h i g h e r (90-120 m g / m 2) doses of CIS w e r e given in 48 c y c l e s (38pts, 21-65 yrs) for tumors of testis or lung. T h e lower (7mg/kg) and h i g h e r (14 mg/kg) d o s e s of M C L per cycle were given r e c t a l l y as microenema. R e c t a l M C L was started w i t h m q / k g or Z m g / k g as loading d o s e 2 hrs before CIS, followed bv same doses at 0 , 4 , 8 , 1 2 , 1 6 , a n d 20 hrs after CIS. In 5 pts (22 - 55 yrs, 61 - 80 kq bw) MCL trough levels and full p l a s m a kinetics after last d o s i n g w e r e m e a s u r e d over 16 hrs. The incidence of emetic episodes (EE) per t r e a t m e n t w a s o b s e r v e d by I e unlnformea members of the staff. Patlents s if e s t i m a t i o n (SE) of severity of v o m i t i n g was m e a s u r e d by 100 m m visual a n a l o g u e scale (VAS). ,

Table A: P h a r m a c o d ~ n a m i c s of e f f i c a c y of rectal M C L CIS per c y c l e ( ) m g / m 50- &90 90-120 M C L per cycle(mg/kg) 7(n=8) 14(n=I0) 7(n=9) 14(n=21) EE per 36 hrs 3,5 1,6 6,0 1,3 m e a n ({anqe) (0 - 5) (0 - 4) (5 - 7) (0 - 5) patients SE (mm) 62 21 75 09 m e d i a n (range) (0-82) (0-62) (71-87) (0-52) Table B: P h a r m a c o k i n e t i c s of rectal M C L 14 m q / k g / c y c Kinetic constants median (range) (n=5] 1 AUC(20-24} 3210 (1820 - 3300) ng x h x kgPlasma ti/2 5,1 (4,3 - 5,6) hrs i _I CL(dose/AUC20-24) 0,63 (0,54 - 1,1) 1 x h-{ x kg " Vdss 5.2 (3.8 - 8.1) 1 x kq-~ T r o u g h Css 385 (350 - 490) ng x ml-" . The pharmacokinetic constants of rectal MCL were very similar to the IV and oral values published previously. Absolute rectal bioavailability was

101%.

T h e results show that the best o b j e c t i v e und subjective r e s u l t s w e r e o b t a i n e d w i t h %he h i g h e r d o s e of MCL. F o r vet u n k n o w n reasons rectal MCL was less effective t h a n intravenous MCL (results published reviousl~). entre of Internal M e d i c i n e and Pharmacoloqy, University,Theodor-Stern-Kai7, D-6000 FrankfurtTa.M. * Kali - Chemie Pharma, D-3000 Hannover. FRG.

~

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PHARMACOKINETICS OF FCE 22178, A NEW THRQMBOXANE SYNTHASE INHIBITOR, IN HEALTHY VOLUNTEERS AND RELATIONSHIP WITH THROMBOXANE B 2 (TxBz) PRODUCTION M. Strolin Benedetti, D. Santarato, E. Pianezzola, M.G. Jannuzzo, C. Ferti and D. Cusi* The objective of this study was to investigate the pharmacokinetics and pharmacodynamics of FCE 22178 [5,6dihydro-7-(iH-imidazol-l-yl)-naphtalen-2-carboxylic acid] in 6 male healthy volunteers given single oral doses of 400 and 800 mg. Blood samples were taken from 0 up to 120 h after administration. Urine was collected within the same interval. Plasma and urinary concentrations were determined by a specific HPLC method with UV detection (E. Pianezzola et al.,unpublished). The inhibition of thromboxane synthase was evaluated measuring by a RIA method serum TxB~, after whole blood clotting at 37~ for lh (C. Patrono et al., Thromb. Res., 17,317, 1980). Drug mean peak plasma levels of 29.3 and 40.7 ~g/ml were obtained within l-2h after the administration of 400 and 800 mg doses, respectively, the corresponding mean values of AUC~__ being 149.4 and 301.7 ~gxh/ml. Plasma half-life values calculated within 24-!20h were 20.5 and !9.3h, rp~pect~veiy. FCE 22178 was excreted mainly as conjugate: the mean urinary excretion of unchanged drug (free+conjugated) up to 120h accounted for 86.3% and 73.0% of the 400 and 800 mg doses respectively. FCE 22178 was able to inhibit thromboxane synthase by 90% within 1 h, the maximal effect lasting for 4 h after 400 mg and 6 h after 800 mg. The recovery of TxB 2 platelet production was not complete until 24 h for 400 mg dose and between 24 and 48 h for the higher dose. The combination of pharmacokinetic and pharmacodynamic information allows to define a rational dosage regimen: on the basis that 2 ~g/ml drug levels are necessary to obtain an inhibition of 60% in the TxB2 platelet production, a repeated doses computer simulation suggests that a 400 mg t.i.d, schedule should be able to obtain a biologically significant TxB 2 reduction over 24 hours. Farmitalia Carlo Erba, R&D - Erbamont Group, Via Imbonati 24, 20159 Milan, *Institute of Medical Sciences, University of Milan, Via F. Sforza 35, 20122 Milan, Italy.

PHARMACOKINETIC-PHARMACODYNAMICMODELINGOF THE EEG EFFECTS OF MIDAZOLAM BY APERIODIC ANALYSIS IN VOLUNTEERS L.T.M. BREIMER, P.J. HENNIS, A.G.L. BURM, M. DANHOF, JOH. SPIERDIJK, J.G. BOVlLL, A.A. VLETTER

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PHARMACOKINETICS AND PHARMACODYNAMICS OF A N E W C L A S S III A N T I A R R H Y T H M I C D R U G (E4031) IN H E A L T H Y SUBJECTS. Y.Tomono, J. H a s e a a w a . M. M i h a r a . H. T a k a h i r a . N. M o r i s h i t a . A. O h n i s h i E 4 0 3 1 is a n e w class III a n t i a r r h y t h m i c c o m p o u n d w i t h a n o v e l c h e m i c a l structure, a n d is n o w u n d e r e v a l u a t i o n for its t h e r a p e u t i c p o t e n t i a l . Methods: E4031 was administered by 5-min i n t r a v e n o u s i n f u s i o n to h e a l t h y s u b j e c t s at doses rising f r o m 0 . 0 1 to i0 ~ g / k g . The pharmacodynamics were assessed from measurements of the Q T c i n t e r v a l . The c o n c e n t r a t i o n s of E 4 0 3 1 in the plasma and the urine were measured by HPLC method. R e s u l t s : The Q T c i n t e r v a l was p r o l o n g e d a f t e r t h e administration of 3 ~ g / k g or m o r e of E4031, a n d t h e e x t e n t of p r o l o n g a t i o n was l i n e a r l y r e l a t e d to t h e dose. The p e r c e n t a g e c h a n g e of Q T c p e a k e d at 2.5 m i n a f t e r t h e e n d of i n f u s i o n , and the v a l u e a f t e r i n f u s i o n of i0 ~g/kg was 23.2 • ii.0 % (mean • S.D., n=8) of the p r e - i n f u s i o n value. The plasma pharmacokinetics of E 4 0 3 1 was b e s t d e s c r i b e d b y an o p e n l i n e a r 3 - c o m p a r t m e n t model, a n d t h e t h r e e h a l f - l i v e s w e r e 1.42 • 0 . 2 1 min, 16.4 • 4.05 m i n a n d 7.01 • 1.09 hr, r e s p e c t i v e l y , a f t e r i0 ~g/kg, the p l a s m a c l e a r a n c e b e i n g 8.51 • 0.57 ml/min/kg. The s e r u m p r o t e i n b i n d i n g was 72.2 • 1.7 %. A Combined pharmacokineticpharmacodynamic model was used to analyze the relationship between QTc prolongation and plasma concentration, a n d the h a l f - l i f e of b i o p h a s e e q u i l i b r a t i o n was 4.64 • 0 . 4 8 min. Conclusion: A strong and selective QTc p r o l o n g a t i o n e f f e c t was d e m o n s t r a t e d for E 4 0 3 1 in man, and no clinically significant unwanted e f f e c t was observed. S e c t i o n of C l i n i c a l P h a r m a c o l o g y , E i s a i Co., Ltd. Koishikawa-4-6-10, Bunkyo-ku,Tokyo, 112 Japan.

DOSE-~CT REIATIONS"HIP OF EPIDURAL NALHUPHINE IN POSTTHORACOYOMY ANALGESIA. S. Lac[aniere, A.D. Baxter, B. Samson and I.J. McGilveray Introduction. Epidural narcotics are being increasingly used for postoperative analgesia. Morphine (M) provides prolonged pain relief but i s associated with delayed respiratory depression. N a ~ HCI (NAL), a potent agonist-antagonist narcotic, possesses analgesic potency similar to M. This study evaluated the efficacy and safety of 2 dose levels of NAL for p o s t ~ t i v e pain. Methods. Twenty-six patients, mean age 56 years (range 24-75), ASA Classes 1-3, undergoing thoraootcxm] or lobectomy were selected. Prior to induction, an epidural catheter was placed at L2-3 or L3-4 and anaesthesia was standardized with NO2/O2, pancuronium, isoflurane, succinylcholine and fentanyl (<5~g/kg). In a doubleblind manner, NAL was administered in a single dose of either 0.075 (N=I0) or 0.15 mg/kg (N=I0) about an hour before the end of surgery. Ccmparisons were made with epidural M (0.15mg/kg) (N=6). Results. There was no statistical difference between the groups prior to and during operation. The pO02 values for the M group were about 50 torr over the first 12 hours post-op; however no respiratory depression (PC02> 50torr) was determined in any group. Pain intensity was recorded and further pain was treated with 25 ~g of fentanyl prn. Results indicated less pain in the M group vs any dose of NAL and, with NAL, higher amounts of fentanyl were required hourly to control the pain. Plasma concentrations of NAL were measured by HPLC ever a 12 hour period. The pharmaookinetic parameters estimated were not statistically significant (p<.05) between the NAL groups. Values found were: Clearance, 1.44 -+ .45 L.kg/h; Vd~, 4.74 _+ 1.08 L/h, TI/2B , 2.4 +_ .5 h.One patient e x p e r i ~ pruritus with M Cohclusions. Our study de~oastrated that epidural doses of .075 and .15 mg/kg were not effective in controlling pain c o ~ to M. Investigations continue with higher

The c l i n i c a l effects of benzodiazepines are usually measured with psychomotoric tests. Such tests lack s e n s i t i v i t y , s p e c i f i c i t y and r e p r o d u c i b i l i t y and cannot be performed continuously. EEG may provide an a l t e r n a t i v e tool to quantitate the effects of benzodiazepines. We investigated simultaneously the pharmacokinetics and pharmacodynamics of midazolam. After obtaining i n s t i t u t i o n a l approval and informed consent, eigth healthy male volunteers p a r t i c i p a t e d in the study. Aperiodic EEG analysis was performed and the t o t a l number of waves in the 12-30 Hz range TNW (12-30 Hz)/s, was used as a measure of e f f e c t . The EEG was recorded between FpI-MI and Fp2-M2 using the Lifescan TM. After a 15 min baseline recording (eyes closed) midazolam (15 mg in 50 ml saline) was administered iv in 5 min and the EEG was recorded f o r 3 h. Blood samples were obtained at regular i n t e r v a l s u n t i l 8 h a f t e r the infusion. Midazolam plasma concentrations were measured by HPLC. Within 2-4 min a f t e r s t a r t i n g the midazolam infusion a l l subjects were asleep with loss of eyelid r e f l e x . The volunteers awoke, unstimulated, 40-70 min a f t e r the s t a r t of the midazolam infusion. The plasma concentration-time data were best characterized by a t r i - e x p o n e n t i a l function f o r a l l volunteers. The pharmacokinetic data were: t l / 2 ~: 186 • 36 min, Vc: 8,9 • 3.8 L, V,,: 78 • 12 L, CL: 391 • 45 ml/min. The effect vs concentration data were characterized by a sigmoid E~x model. Pharmacodynamic parameters were: t l / 2 k e o : 1.7 • 0.7 min, Eo = 0.7 • 0.43 waves/s, Em~: 9.7 • 1.5 waves/s, ECs0:290 • 98 ng/ml, The results indicate that at least in volunteers the EEG effect of midazolam can be quantitated adequately using an aperiodic EEG analysis technique. University Hospital Leiden, Dept. of Anesthesiology, P.O. Box 9600, 2300 RC Leiden, The Netherlands.

d~

of ~ibuphine.

Bureau of Drug Research and Dept. of Anaesthesia, Univ. of Ottawa, Ottawa, Canada, KIA-OI2.

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PLASMA CONCENTRATIONS OF IMMEDIATE (IR) AND SUSTAINED (SR) RELEASE PARACETAMOL AND THE SIMILARITY TO ANALGESIC EFFECT H. Quiding, C. Graffner, H. Arwidsson and Y. Jaksch Sustained release formulations of paracetamol will provide convinience to patients on long time therapy and may also suppress pain during a whole night. The purpose of this cross-over study was to investigate the plasma concentration after single and repeated doses of paracetamol 4 gm daily. In a randomized way 12 healthy volunteers received I gm paracetamol as standard tablets q.i.d., 2 gm paracetamol IR+SR in relation I+3 b.i.d, and 2 gm paracetmol SR b.i.d. After a single dose C , t and AUC was 15.4, 9.9 and 6.9 ug/ml, 0.~axl .6 max tot 56, 97 and 4.0 hours, and 90 ugxh/ml respectively. At steady-state the corresponding values were 17.3, 11.8 and 9.4 ug/ml, 0.5, 1.7 and 3.0 hours, 53, 80 and 77 ugxh/ml (AUC ). Steady state pre-dose levels were 3.3, 0- n 3.1 an~ 3.5 ug/ml after 4 days administration of tablets, IR+SR and SR and the half-lives were 3.6, 4.4 and 5.4 hours respectively. The present formulations have been investigated clinically (Quiding et al Clin Pharm Ther 45 No 2 1989) and the analgesic effect curves are similar to the present plasma concentrations. However, the results indicate that high initial peak concentrations of paracetamol do not correspond to better analgesic efficacy. Thus, SR paracetamol may be an important formulation in clinical practice. Clinical Research, Astra L~kemedel AB S-151 85 S~Sdert~lje, Sweden

THE P H A R M A C O K I N E T I C S A N D P H A R M A C O D Y N A M I C S OF L I S I N O P R I L B A S E D ON ITS B I N D I N G C H A R A C T E R I S T I C S T . O g u m a r T . Y o s h i k a w a , H . Y a m a d a and M . N a k a s h i m a The p r o t e i n b i n d i n g of l i s i n o p r i l has not been studied in detail. Recently, it was s u g g e s t e d that the n o n l i n e a r p h a r m a c o k i n e t i c s of l i s i n o p r i l m i g h t be e x p l a i n e d by the s a t u r a b l e b i n d i n g to A C E ( A n g i o t e n s i n c o n v e r t i n g enzyme) (Beermann, Acta Pharmacol. Toxicol., 49, 66, 1986). In this study, the p r o t e i n b i n d i n g c h a r a c t e r i s t i c s of l i s i n o p r i l in h u m a n serum and the p h a r m a c o k i n e t i c - p h a r m a c o d y n a m i c relationship of lisinopril in v o l u n t e e r s f o l l o w i n g oral a d m i n i s t r a t i o n were i n v e s t i g a t e d . The p r o t e i n b i n d i n g d e t e r m i n e d by u l t r a f i l t r a t i o n was shown to be s a t u r a b l e in serum at the very low c o n c e n t r a t i o n of 10 ng/ml. The b i n d i n g and ACE a c t i v i t y were d e t e r m i n e d in the s e r u m p r o t e i n f r a c t i o n s w h i c h was s e p a r a t e d by a S e p h a c r y l S-300 column. The b i n d i n g and ACE a c t i v i t y were o b s e r v e d in the same p r o t e i n fractions, s u g g e s t i n g l i s i n o p r i l binds to ACE. The k i n e t i c s of the b i n d i n g of l i s i n o p r i l to ACE was a n a l y z e d as well as p h a r m a c o k i n e t i c s of l i s i n o p r i l in v o l u n t e e r s f o l l o w i n g oral a d m i n i s t r a t i o n . The time course of the r e m a i n i n g ACE a c t i v i t y c a l c u l a t e d as u n b o u n d f r a c t i o n of ACE using the b i n d i n g and p h a r m a c o k i n e t i c p a r a m e t e r s o b t a i n e d from the a n a l y s e s c o r r e s p o n d s with that of the o b s e r v e d b l o o d p r e s s u r e r e d u c t i o n in v o l u n t e e r s f o l l o w i n g oral a d m i n i s t r a t i o n . The p h a r m a c o d y n a m i c s of l i s i n o p r i l can be d e s c r i b e d by the p h a r m a c o k i n e t i c s ,and the b i n d i n g k i n e t i c s of the drug. Shionogi R e s e a r c h L a b o r a t o r i e s , 5-12-4, Sagisu, F u k u s h i m a - k u , O s a k a 553, Japan.

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S U L P I R I D E H A S A HIGHER PROLACTIN INCREASING POTENCY THAN REMOXIPRIDE, A N E W SELECTIVE DOPAMINE D2-RECEPTOR ANTAGONIST

CHARACTERIZING THE EFFECT OF PARENT COMPOUED ON THE IN VITRO POTENCY OF THE METABOLITE OF FIVE ACE INHIBITORS JR Harrigan, DMHughes, PA~Meredith an___d_dJLReid. Hysteresis has been observed following the oral administration of perindopril but not after intravenous dosing of its metabolite perindoprilat. Work already carried out to compare the in vitro potency of different ACE inhibitors highlighted the difference between species whilst demonstrating the consistency within species. The present study examines the effect of parent compound on the in vitro potency of the metabolite in rabbit and man. Dose response curves for enalaprilat, perindoprilat, benazaprilat, S-I0211 and quinaprilat were prepared. The curves were fitted to Hill and Langmuir models and model selection made on the basis of the F-Ratio test. Potency was measured using C50 values, the concentration of metabolite producing 50% inhibition. The effect of parent compound was studied by repeating the dose response curves for the metabolites in the presence of the parent compound. In rabbit, while no effect of parent was detected for enalapril, perindopril or benazapril, the presence of parent increased the C50's for S-I0211 and quinaprilat by 55 and I04~ respectively. In man the presence of parent increased the C50's for enalaprilat and perindoprilat by 21 and 110% respectively. No effect was observed for the remaining three compounds. In addition, in man only, the effect of perindopril on enalaprilat caused a 26~ increase inthe C50 for enalaprilat, similar to the increased observed in the presence of enalapril. These studies further highlight the differences between species and suggest that some parent drugs, by a mechanism such as steric b~ndrance, may perturb the concentration/ACE inhibition relationship of the active metabolites. This may account for the hysteresis observed after oral administration of perindopril. Department of Materia Medica, Stobhill General Hospital, Glasgow~ Scotland, G21 3UW.

C. yon Bahrl~ G. Movin I, P. Eneroth 2, P. Jansson I , F.-A. Wiesel ~ Si~ female and six male healthy volunteers (23-40 years) received i00 mg remoxipride, a new antipsychotic drug, and 200 mg sulpiride and placebo as single oral doses in a double-blind trial with a randomized crossover design. The objective was to compare the effect of the two drugs on plasma prolactin levels.

Frequent blood sampling was performed during 36 hours after drug administration. Remoxipride and aulpiride concentrations in plasma were determined by HPLC and prolactin concentrations in serum by RIA-technique. Sulpiride and remoxipride increased the serum levels of prolactin to similar levels. The effect ,#as larger in female than in male subjects. Sulpiride increased prolactin levels at much lower plasma concentrations than remoxipride, and the effect of sulpiride persisted much longer. Sulpiride thus had a higher potency for prolactin release than remoxipride. Plots of drug concentration vs prolactin increase exhibited a marked hysteresis for sulpiride but not for remoxipride. Both remoxipride and sulpiride were well tolerated. Adverse symptoms were in general mild and the pattern was similar within the three treatments. IDepartment 9f Clinical Research, Astra Research Centre, s~dert~lje ~Unit~for Applied Biochemistry, Euddinge Research Centre, Department of Psychiatry, Karol~nska Hospizal, Karolinska Institute, Stockholm, Sweden.

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DIURETIC EFFECT AND DIURETIC EFFICIENCY AFTER IV DOSAGE OF FUROSEMIDE G. A l v ~ n , L. H e l l e d a y , A. L i n d h o l m , E. S a n z a n d T. V i l l @ n The diuretic effect of furosemide can be interpreted according to the Hill equation, the stimulus being excretion rate of furosemide. Howe v e r , t o t a l c u m u l a t e d e f f e c t o f a d o s e g i v e n is independently a consequence of acute effectconcentration relationship and the pharmacokinetic concentration pattern of the drug. Efficienc y is t h e v a r i a b l e t h a t b r i n g s a m o u n t o f e f f e c t p e r a m o u n t o f s t i m u l u s i n t o a c c o u n t a n d is o b tained dividing both hand sides of the. Hill+ e~ation by the stimulus: Eff = Em'cS-• c ) w h e r e E f f is e f f i c i e n c y , E m is m a x i m u m D ~ f e c t , C is s t i m u l u s , C_0^ is s t i m u l u s a t w h i c h 5 0 % o f t h e m a x i m u m d r u ~ ~ f f e c t is o b t a i n e d a n d s is a s l o p e f a c t o r . W e i n v e s t i g a t e d the consistenvy of measured diuretic efficiency for volume, Na , Cl- and K- with that derived from the stimulus-effect relationship a f t e r iv a d m i n i s t r a tion of furosemide (0.5 m g / k g bw) in f i v e healthy subjects. The Hill parameters were estimatedby nonlinear regression. The urinary recovery of furosemide was 74-95% of dose. There was a general consistency over the range of C between efficiency calculated from the Hill-parameters and that obtained from direct observatio n s w h i c h is a l s o t o b e e x p e c t e d a s t h e s a m e e x perimental observations was the origin for both estimations of Hill parameters specifying the diuretic effect and calculation of diuretic efficiency. The relative values of C~0 ~ and the furosemide excretion rate related ~o~ efficiency were dependent on whether s was less o r g r e a t e r t h a n 2 as t h e o r e t i c a l l y predicted. Dept of Clinical Pharmacology,~Huddinge University Hospital, S - 1 4 1 86 H u d d i n g e , Sweden

APIS : A SOFTWARE FOR CLINICAL PHARMACOKINETICS A. Iliadis APIS is a user-friendly software package which provides a reliable approach in optimizing drug therapy. This software was designed to assist clinicians in interpreting serum drug levels so that drug therapy may be more cost-effective. The phsrmacokinetic analysis is based on mathematical modeling. APIS incorporates the principles of Bayesian pharmaeokinetics, making it possible to use partial patient information to determine patient-specific phsrmacokinetic parameter estimates. The parameter estimates can then be used to design an optimal and individualized drug regimen. Dynamical and steady-state dosage adjustments are possible, allowing either a quick or a progressive achievement of clinical objectives. The study of linear mammillary models, associated with intra- or extravascular routes and single or repeated dose administrations, results in a complete review of particular cases. Extensive graphics capabilities enable the clinicial to display a patient's current concentration-time profile or to simulate that of a new drug regimen. APIS may be used on any IBM or i00 % IBM compatible PC/AT, PS using the WINDOWS-MICROSOFT environment. The software is menu driven to provide a very user-friendly tool. Print-outs of the patient data and graphs can be generated by using a variety of dot matrix printers or digital plotters. As it enables physicians to rapidly determine and attain therapeutic drug levels, APIS is an attractive and useful tool for developments in clinical pharmacokinetics. It reduces the cost of patient care without reducing quality. INSERM U 278, Faeult~ de Pharmacie, 27, bd Jean Moulin 13385 MARSEILLE C@dex 5

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QUINOLONE INHIBITION OF CAFFEINE DISPOSITION IN HUMANS R. de la Torre. G. Barnett, M. Carb6 and J. $e~ura Quinolone antimicrobial therapy is an area of current research activity, due to the development of the new synthetic 6-fluoroquinolones. Drug-drug interactions with methylxantines, wich frequently result in altered methylxantine plasma levels, have been r e p o r t e d . Two studies reported by Carb6 et al. (Clin. Pharmacol. Ther. 1989, i n press) and Staib et al. (Eur. J. Clin. Pharmacol. 9, 193, 1987l provide a database upon wich we analyze (using SAAM-Consam software) the C-t curves for norfloxacine (NFC), pipemidic ac. (PPA), ciprofloxacine (CIP), enoxacine (ENX) and ofloxacine (OFL), and develop a relatively simple pharmacokinetic model for the interaction of these quinolones with caffeine (C) metabolism in humans. Caffeine kinetics was best described by 1-compartment model with first order absorption and elimination. The effect of quinolones was found to be best described as an inhibition of C elimination, thus resulting in a nonlinear elimination process. The inhibiton constants (Ki) were determined. On the basis of values obtained, a scale of relative p o t e n c y for the quinolones as inhibitors, may be proposed. ENX (Ki=l.8) is the most potent, OFL has no apparent effect on C elimination, CIP (Ki=0.2) and NFC (Ki=0.17) are equipotent and 1/10 th the strength of ENX, while PPA (Ki=0.81) is 1/4 th of its potency. A unified model for the evaluation of the effect of quinolones on the disposition of C has been developed. It is also directly aplicable to the interaction with other methylxantines (i.e. theophylline). Dept Pharmacol, Inst Mun Inv Med (IMIM), P.Maritim 25, 08003-Barcelona, Spain. Acknowledgments: supported by a grant #188/84 of CAICYT.

COMPARATIVESTUDY OF THE NEW TOPICALCARBONIC ANHYDRASE INHIBITORMK-927 AND ITS S-ENANTIOMERMK-417 IN MAN. N. Pfeiffer, ]'. Gerling, L. Lippa.F. Brunner-Ferber and F. Grehn The Carbonic anhydrase inhibitor (CAI) MK-927 has been shown to lower intraocular pressure (IOP) in glaucoma patients (R. Hennekes, N. Pfeiffer et al. Invest. Ophthalmol Vis Sci 1988, 29:82). We investigated efficacy and local tolerability of MK-927 (1% & 2%) and for the first time in man of its S-enantiomer MK-417 (1% & 1.8%). The investigation was performed in a double-masked, randomized, placebo-controlled, five-period crossover fashion in twenty volunteers. A single drop of the test c o m p o u n d was administered bilaterally at 2 p.m. Subjects were monitored for tolerability and side-effects. IOP was measured three hours postdrop and was found to be decreased doseKtependantly with all four CAI treatments, significantly so with MK-417 (mean IOP decrease 9.1% of baseline, p<.05). Pupil-size was not changed by the drugs. Compared to placebo, subjects reported increased burning and tearing for all CA1 solutions tested. Incidence and intensity of burning were dose dependent and significantly more than that caused by placebo (p<.05). Also, the mean duration of burning a n d tearing were significantly prolonged as compared to placebo (p<.01 and p<.05). In this model a single drop of I or 1.8% MK-417 seems to penetrate the intact cornea well enough to quantitatively inhibt the h u m a n carbonic anhydrase present in the ciliary body. The IOP lowering effect of MK-927 and MK-417 and good local tolerability in the absence of an influence on pupil-size suggests a high potential as topical glaucoma drugs and warrants further evaluation in patients. Department of Ophthalmology, University Hospital, D-7800 Freiburg, FRG and MSD Clinical Pharmacology, West Point USA

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THE EFFECT OF A SINGLE ORAL DOSE OF PERGOLIDE ON INTRAOCULAR PP~ESSURB ~ND PUPIL DIAMETER IN NORMAL VOLUNTEERS M. R. Al-Sereiti , R. F. P. Quik and P. Turner It has been shown that bromocriptine (B) in a single 1.25 mg oral dose (Q. Mekki, et al. Lancet i, 1250, 1983) and 0.025% eye drops (Q. Mekki, et el. Lancet i, 287, 1984) and lisuride in a single 0.1mg oral dose (M.R. Ai-Sereiti & P. Turner, Br. J. Clin. Pharmacol. 1989 (in press)) reduced intraocuiar pressure (IOP) in normal human eyes significantly compared with placebo. Pretreatment with metoclopramide, a relatively selective D2-receptor antagonist, abolished the effect of B eye drops on IOP (Q. Mekki & P. Turner, Br. J. Ophthalmol. 69, 218, 1985). B also reduced IOP in glaucoma patients (O. Geyer, et al. J. Ocular Pharmacol. 4, 291, 1987). Pergolids (P) had a longer duration of action and was more potent than B in terms of IOP reduction in monkeys (D. Potter & J. Burke, Curt. Eye Res. 2, 909, 1983}. P produced mlosis in rabbits (D. Potter & J. Burke, Curt. Eye Res. 2, 909, 1983) and mydriasis in monkeys (M. Siegel, et al. Exp. Eye Res. 44, 227, 1987). The effect of P on human pupil diameter (PD) has not been studied. 12 healthy volunteers were given a single oral dose of 25ug P, 10mg timolol (T) as a positive control, or matched placebo, on three occasions in a double-blind, cross-over design. IOP was measured by non-contact tonometry, just before and at i, 2, 3, 4, 5 and 6 hours after treatment. PD was measured by photography, just before and at 1.5, 3 and 4.5 hours after dosing. Postdosing data were analysed by multiple regression with base line values included as a continuous independent variable. Considering all postdosing measurements, compared with placebo, IOP was reduced significantly by both P and T in both right and left eyes (p< 0.0001). Neither of the drugs had a significant effect on PD. these results support the finding that D2-recepter agonists reduce IOP and show that P is a potent ocular hypotensive drug with no effect on PD. i. Clin. Pharmacology Depart., St Bartholomew's Hospital, London, ECIA 7BE. 2. Lilly Research Centre Ltd, U.K.

TOLERABILITY AND PHARMACOKINETICS OF A NEW URINARY TRACT ANTISPASMODIC DRUG, REC 15-2053, IN HEALTHY VOLUNTEERS. E. Colli, M. 8catigna, A. 8artani,A. Tajana, S.J. Warrington and S. Turner REC 15-2053 is a new flavone derivative (D. Nardi et al., British Patent no. 2104507, 1981) chemically correlated to flevoxate. In various experimental models, REC 15-2053 produced spasmolytic activity at the bladder level (C. Pietra et al., Neurology and Urodynamics, 6 (3),247,1987). Binding studies (G.A. Abbiati et al., Pharmaceutical Res., 5 No. 7,430,1988) on receptors directly or indirectly involved in the nervous control of the lower urinary tract functions showed that REC 15-2053 is devoid of antioholiS nergic activity and presents only a weak binding to H-nitrendipine and muscarine receptors (IC O14 ~ H and 19/uM respectively), too low to account for its mechanism of action. REC 15-2053 has shown a high PDEI inhibition activity, which might be related to its muscle-relaxing activity (R. Testa, Personal communication). In a single dose tolerability study, 8 healthy male volunteers received orally up to 600 mg of REC 15-2058. Tolerabiiity was very good; no adverse symptoms or change in heart rats, blood pressure, ECG or laboratory screening were observed. Pharmacokinetics were investigated in those subjects ~iven 50 a n d 4 0 0 mg. REC 15-2053 was rapidly absorbed, with mean T m a x values ranging l-2h for both doses. Peak plasma concentration (Cmax) averaged 1.72• and 3.99• ~g/ml after the 50 and 400 mg doses respectively. Half life was 27.6• h for the 50 mg dose and 29.7• for the 400 mg dose. Repeated dose tolerability studies are ongoing. The dose of 50 mg once a day for two weeks was very well tolerated.

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EFFECTS OF NIFEDIPINE AND ~TOPROLOL ON INTRAOCULAR PRESSURE IN HEALTHY SUBJECTS T. Walley, S. Kelly Nifedipine (N) is associated with eye pain, possibly due to raised intraocular pressure (lOP) because of retinal arterial dilation (Coulter D, Br Med J 1988; 296: 1086). N, often used in hypertension or angina in the elderly, might therefore adversely affect pre-existing glaucoma. We studied the effects of N, given alone and after pretreatment with metoprolol (to determine if this ~ u l d protect against the expected rise in lOP), on lOP (measured by Goldman applanation tonometer), blood pressure (BP), heart rate (HI{) and forearm blood flow (FBF, by strain gauge plethysmagraphy). 6 healthy subjects were given N (0.75 mg bolus and 1.2mg infusion for 6 hours and then 20ms oral slow release tablet this regimen maintains plasma levels between 20-30 ng/ml), or matching vehicle placebo in a double blind study. On a third open day, subjects were pretreated with metoprolol 100rag 12 hourly for 48 hours before receiving N. lOP, HR, BP and FBF were measured pre treatment and at 3 and 8 hours during treatment.

ABSENCE OF METABOLIC EFFECTS OF THE NOVEL TOPICALLY ACTIVE CARBONIC A N H Y D R A S E I N H I B I T O R M K - 9 2 7 A N D ITS S - I S O M E R DURING A T W O - W E E K OCULAR ADMINISTRATION. T Buclin~ EA Lippa~ J Biollaz~ F Brunner-Ferber~ M Sch~neich; R Fa~oloni~ A Ykmafo~ JL Scheilin@. To investigate the systemic and especially renal effects of an o p t h a l m i c s o l u t i o n of the r a c e m a t e M K - 9 2 7 (R/S) at 2% and its more active S-enantiomer MK-417 (S) at 1.81, a double-masked, r a n d o m i z e d p l a c e b o - c o n t r o l l e d s t u d y w a s performed in 16 h e a l t h y s u b j e c t s s u b m i t t e d to an 18-day controlled diet. F o l l o w i n g 4 days for m e t a b o l i c e q u i l i bration, a b i l a t e r a l , q.i.d, r e g i m e n w a s s t a r t e d for 14 days, 6 s u b j e c t s r e c e i v i n g a t o t a l d a i l y dose of 4.8 m g R/S, 6 of 4.3 m g S and 4 of the vehicle. B l o o d and u r i n e parameters (electrolytes, urate, citrate, creatinine, osmolality) and a c i d - b a s e p r o f i l e s w e r e m e a s u r e d on 5 split s p e c i m e n s , p r i o r to and on Day I, 7, 14 of t r e a t ment. Daily 24-hour urine was also collected. The ratio of the t r e a t m e n t vs Day -i v a l u e s w e r e c o m p a r e d by m u l t i variate ANOVA, the factors being treatment, study day and sampling time. Nyctohemeral variations remained similar, in phase and intensity, f o r all parameters and treatment groups. P e r c e n t a g e c h a n g e s vs Day -i are l i s t e d in t a b l e below: Urinary excretion R/S S Vehicle Profile days: sodium ~ - ~ potassium + 9~0 + 6% - 5~ citrate + 12~ + 5~o + 15~ Over the 14-day treatment period the total daily excretion of creatinine, Na, K and citrate differed from the vehicle by less t h a n 3, 12, 12 and 2.3%, r e s p e c t i v e l y . None of t h e observed differences were statistically significant. Local and systemic tolerance was good. Taking into account biological variability~ this study design would have detected any clinical ly relevant changes due to therapy. In conclusion, MK-927 and M K - 4 1 7 a d m i n i s t e r e d t o p i c a l l y s 2 w e e k s do not i n d u c e s i g n i f i c a n t m e t a b o l i c c h a n g e s either statistically or clinically. DivJslon of C l i n i c a l P h a r m a c o l o g y , U n i v e r s i t y Hospital, Lausanne, Switzerland and MSDEL, West Point, PA, USA.

lOP (Mean + sere)

Placebo

N

N + matoprolol

12.6 + 1.8 ]2.6 + 1.2 ]3.0 + 2.6

13.6 + 2.3 11.6 + 1.7 i0.0 _+ 2.2

9.4 + 2.3 9.3 + 1.8 8.9 + 1.7

mmHg Pre 3 hrs 8 hrs

Metoprolol significantly reduced lOP (P ~ 0.05), while N had no effect. N increased HR during bolus administration (5.7 _+ 2.0 bts/min, P g 0.05), but had no effect chronically. N had no significant effect on BP. Metoprolo] decreased HI{ by 10 + 2.2 bts/min and mean BP (=DBP + 1/3 x pulse pressure) by i0 + 2.4 mm Hg compared to other trial days (P < 0.05 for both). N increased FBF, both in the presence and absence of matoprolol (64 + 15 and 73 + 20% respectively, P ~ 0.05). N, in vasodilating doses, does not increase lOP in normal subjects, and is not contraindicated in glaucoma. Depts. of Pharmacology and Therapeutics and Ophthalmology, University of Leicester, Leicester LE2 7LX, U.K.

Recordati S.p.A. Medical and Pharmacokinetic Departments Via Civitali, i, 20148 Nilan (Italy). - Charterhouse, Clinical Research Unit L t d -

London (U.K.)

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PHARMACOLOGICAL TREATMENTOF DRUG DEPENDENCEIN PATIENTS SUFFERING FROM DAILY CHRONIC HEADACHE E. S t e r n i e r i , G. Bergonzini, A. Ferrari, L. G i r o l d i , and L.A. Pini

ROLE OF DOPAMINE IN REINFORCEMENT EFFECTS OF PHENCYCLIDINE (PCP) IN THE RAT MODEL OF INTRAVENOUSDRUG SELFADMINISTRATION J. E. Moreton and K. L. Marquis Phencyclidine (PCP) an arylcyclohexylamine dissociative anesthetic is abused by humans and supports self-administration behavior in animal models. The self-administration of several psychomotor stimulant drugs appears to be mediated by dopaminergic mechanisms in the brain. Since phencyclidine inhibits dopamine uptake, dopamine may contribute to the reinforcing effects and abuse potential of PCP. Therefore, the effects of the dopamine receptor haloperidol on PCP self-administration were determined in comparison with its effects on cocaine self-administration in the rat. Female $prague-Dawley rats bearing a chronic indwelling jugular vein cannula were trained to intravenously self-administer cocaine (i mg/kg/inj) or PCP (0.5 mg/kg/inj) in daily 3 hour sessions on a fixed-ratio lO schedule of reinforcement. Pretreatment with haloperidol (0.05 to 0.i5 mg/kg ip) i hour prior to a ~elf-administration session, either increased or decreased the number of cocaine injections. A decrease was associated with an extinction pattern of responding. In contrast, haloperidol pretreatment produced only decreases in the number of injections of PCP without an apparent extinction pattern. Repeated injections of haloperidol (0,075 mg/kg ip) for 7 consecutive self-administration sessions produced a sustained reduction in number of PCP injections per session. These data are in contrast with previous reports of continued increases in number of injections of cocaine with repeated haloperidol treatment (Roberts and Vickers, Psychopharmacology 93:526, 1987). Our preliminary results indicate that both acute and repeated treatment with haloperidel alter PCP self-administration in a manner that is different from its effects on cocaine self-administration. (Supported by NIDA grant DA03173) Dept. Pharmacology and Toxicology, University of MarySchool of Pharmacy, Baltimore, Maryland, USA, 21201

Daily use of analgesic drugs, even i f i n e f f e c t i v e , is common in d a i l y chronic headache (DCH). Generally t h i s is considered "abuse", but in DSM I I I abuse is defined as a pathological use associated with worsening of social or domestic relations due to drug use. This does not happen in individuals suffering from headache. They use analgesics to improve t h e i r social capacity by eliminating pain. Looking at t h i s type of use (which is neither "abuse" nor "misuse") we prefer to define i t as a " d a i l y use", a l though sometimes the symptoms which present a f t e r discontinuing drugs containing barbiturates or codeine may resemble withdrawal. In a series of 2661 headache sufferers who v i s i t e d our center between 1982-88, we found 278 (10.45%) patients with DCH, 77 of them (27.7%) using drugs d a i l y and one half using mixtures containing barbiturates. The main problem, which is more evident in patients using barbiturates, is to prevent relapses a f t e r druq use is discontinued. We propose the following therapeutic program: (I) Discontinue the use of mixtures, prescribe decreasing doses of single drugs, and replace short- with long-acting barbiturates, (2) use symptomatic drugs to a l l e v i a t e withdrawal symptoms, and (3) start prophylactic treatment f o r headache. At the end of t h i s schedule 57% of patients had improved by more than 50%, and 3 months l a t e r 36% had not relapsed. Department of C l i n i c a l Pharmacology, University of Modena Via del Pozzo, 71, 41100 Modena, I t a l y

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COCAINE TOXICITY AFTER PRE- AND POST-NATAL VALPROIC ACID (VPA) EXPOSUREIN RATS S.K. Sobrian, N.L. Robinson, L.E. Burton, H. James and A.K.N. Nandedkar This laboratory has reported that VPA prevents cocaine-induced convulsions (CICs); y e t , VPA gretreatment (VPA-P) increases cocaine's f a t a l i t i e s twofold and the incidence of cocaine sudden death. Prenatal VPA protects offspring against VPA/cocaine t o x i c i t y but reduces i t s postnatal anticonvulsant activity. Offspring of rats exposed to VPA (PV) or water (control:PC) on gestation days 15-21 were treated at 60 or 180 days of age with 200mg/kg of VPA, or vehicle, 30 min p r i o r to a 60mg/kg i . p . dose of cocaine. Cocaine toxicfty was scored and compared with EKG and enzyme a c t i v i t y from serum taken immediately after behavioral testing to determine the affected organ systems. Total lactate dehydrogenase (LD) was elevated in animals that died without CICs compared to those that convulsed or showed no t o x i c i t y . Liver enzymes (alanine aminotrasferase:ALT) were increased in animals that convulsed but decreased in animals that died (gamma glutamyl transpeptidase:GGT). VPA-P also increased t o t a l LD and ALT, but not GGT. Neither total creatinine kinase (CK), CK-MM, (muscle), CK-MB (cardiac) nor EKG parameters correlated with cocaine t o x i c i t y . However, CK-MB was increased in a l l cocaine rats and CK-BB (brain) was increased by ClCs. Results suggest that cardiac involvement in cocaine f a t a l i t i e s may be secondary to derangement in l i v e r function. The increase in CK-BB followfng ClCs implicates the CNS as a major mediator of cocaine t o x i c i t y , and introduces this isoenzyme as a serum marker for abnormal brain a c t i v i t y . Behavioral data dictate caution in using VPA t h e r a p e u t i c a l l y in cocaine i n t o x i c a t i o n . Depts. Pharmacol. & Biochem., Howard University, College of Medicine, Washington, D.C. 20059, USA.

EVALUATION OF THE ABUSE POTENTIAL OF ZOLPIDEM ~).R. Jasinski and D.R. Preston

Zolpidem, a selective agonist of benzodiazepine 1 receptors, used clinically as a hypnotic. To learn if zolpidem produces a diazepam-like profile of effects the subjective effect profile of zolpidem 10, 20, and 40 mg were compared with those of diazepam l0 and 20 mg and placebo in 12 volunteer male substance abusers using a double blind crossover technique. Drugs were administered orally according to two 6 x 6 latin squares on consecutive days while the subjects resided on an experimental research unit. Subject-rated measures consisted of visual analog scales for self-reported drug efect, drug identification, liking and disliking, and other symptoms, and subscales from the ARCI. Observer measures consisted of visual analog scales measuring drug effect, drug liking and disliking, and various signs. Vital sign changes were assessed concurrently. Measures were taken prior to drug administration and at 30 to 60 min intervals for six hours and then at three to six hour intervals until 23 hours post dosing. In the doses tested zolpidem was psychoactive with a shorter onset and duration than diazepam for self-reported drug effects. Subjects identified the effects of zolpidem as benzodiazepine-fike and reported increased scores for liking, disliking, and high and on the sedation and euphoria scales of the ARCI similar to those produced by diazepam. The prbfile of effects following zolpidem administration, however, was not identical to that of diazepam. Diazepam was clearly more sedating than zolpidem as indicated by identification of diazepam, but not zolpidem, as a barbiturate or sleeping medication and greater degree of reported sleepiness and decreased energy. Observers reported more intense "sleepy" and "nodding" scores for diazepam than zolpidem. Zolpidem, but not diazeparn, produced reports of visual disturbances (primarily diplopia) and greater ratings of confusion. Zolpidem, but not diazepam, increased heart rate in the supine position and blood pressure in the erect position. On the basis of these studies, we conclude that single oral doses of zolpidem and diazepam produced similar but not identical profiles of effects in substance abusers and that zolpidem has some potential for abuse of the diazepam type. Francis Scott Key Medical Center, Johns Hopkins School of Medicine, D-5-West, 4940 Eastern Avenue, Baltimore, MD 21224, U.S.A.

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PP 06.05 DIFFERENTIAL

PATTERNS

PP 06.07 OF B E N Z O D I A Z E P I N E

ABUSE

Benzodiazepines (B) are f r e q u e n t l y u s e d drugs. High dose abuse of t h e s e d r u g s is r a r e and patterns of abuse have not been well characterized. D a t a on p a t i e n t c h a r a c t e r i s t i c s (e.g, age, sex) a n d p a t t e r n s of d r u g use (e.g. name, dose, d u r a t i o n and f r e q u e n c y of use) w e r e systematically collected in 284 patients, meeting DSM III-R criteria for B abuse, admitted to the Clinical Institute of the Addiction Research Foundation. T w o g r o u p s of abusers were identified: abusers of only B (ABO) (N=41) a n d m u l t i p l e d r u g a b u s e r s (MDA). M D A w e r e f u r t h e r d i v i d e d in p r i m a r y B a b u s e r s (PBA) (N=I31) a n d n o n - p r i m a r y B a b u s e r s (NPBA) (N=II2). ABO abusers were significantly older (p<0.05) than both PBA and NPBA (age, x + SD: A B O = 37 + 11.6 yrs; P B A = 28 + 7.6; N P B A = 32 + i0). Male:female r a t i o was i:i i n all 3 groups. Median abused doses were 2-4 times higher than maximum recommended doses (dail~ dose, mg/day, d i a z e p a m e q u i v a l e n t s , x + SD: A B O = 83 # 92; P B A = 167 + 241; N P B A = 113 + 205). M o s t f r e q u e n t l y abused' B w e r e d i a z e p a m (60%), chlordiazepoxide (9~), oxazepam (8~) and lorazepam (7%). Rapidly eliminated B (e.g. oxazepam, lorazepam) were more frequently a b u s e d by A B O (39%) and P B A (31%) t h a n by N P B A (17%). In MDA, the m o s t c o m m o n o t h e r d r u g of a b u s e was e t h a n o l w h i c h was m e n t i o n e d b y 142 patients (58%), f o l l o w e d by c a n n a b i s 82 (34%), codeine 81 (33%) and b a r b i t u r a t e s 73 (30%). These data show that B can be exclusively a b u s e d at h i g h d o s e s b u t are m o s t l i k e l y to be a b u s e d in c o m b i n a t i o n w i t h o t h e r drugs. Pharmacy Department, Addiction Research Foundation, a n d F a c u l t y of P h a r m a c y , U n i v e r s i t y of Toronto, 33 Russell Street, Toronto, O n t a r i o , M5S 2SI CANADA.

SEROTONIN UPTAKE INHIBITORS (SUI) DIFFERENTIALLY ALTER ADDICTIVE BEHAVIOURIN PROBLEM DRINKERS C.A. Naranio. E.M. Sellers and K.E. Kadlec Alcohol consumption and cigarette smoking are widespread, highly .correlated addictive behaviours. Effective pharmacological interventions to decrease the consumption of alcohol and tobacco are not available for clinical use. Years ago we developed a research program for testing the effects of SUI on addictive behaviour in problem drinkers, The effects of four SUI (zimeldine [Z], citalopram [C], viqualine [V] and fluoxetine [F]) on consumption of alcohol and cigarettes were assessed in double-blind, randomized, placebo (P)-controlled studies in male problem drinkers. Compliance with SUI treatment was objectively determined and no advice or other intervention was administered. In a crossover study (n = 13), Z 200 mg/day decreased daily alcoholic drinks from baseline by an average of 14.2% to 5.5 + 0.9 (x_.+SEM) compared with 6.0-- 0.8 during P (F1 12 = 5.8, p < 0.05~- In other crossover studies, C 40 mg/day (n ~- 19) decreased daily drinks compared with P (6.7--+ 0.7 vs. 6.0-+ 0.8, F1 17 = 5.3, p < 0.05), with average decreases from baseline of 16.2% (0 40 mg/day) and 5.5% (P), and V 200 mg/day (n = 14) decreased daily drinks to 6.4-+ 0.8 compared with P (7.7-- 0.8) (F1 12 = 5.3, p < 0,05). Average decreases from baseline were 20.5% (V ;~00 mg/day) and 2.4% (P). Smoking (cigarettes/day during SUI vs. P in daily cigarette smokers) was not significantly affected by Z 200 mg/day (25.9-+ 3.9 vs. 27.1 + 3.9, n = 5), C 40 mg/day (19,1 + 4.4 vs. 19.6-+ 4.2, n = 8), or V 200 mg/day (33.1 -+ 7.6 vs. 36.3 + 6.6, n = 6) (all p > 0.05). In a parallel design study F 60 rag/day (n = 11) decreased daily alcoholic drinks from 8.3 + 0.7 during baseline to 6.9-+ 0.7 (F1 10 = 16.2, p < 0,01) with an average decrease of 17.3%. The 7 daily sm~)kers significantly increased cigarettes/day from 25.1 + 4.6 during baseline to 26.9 + 4.5 during F 60 (F1 6 = 11,0, p < 0.05)--P (n = 10 drinkers, n = 5 smokers) had no significant effects (p > 0.05). Our results show that SUI consistently decrease alcohol consumption whereas cigarette smoking is not altered. These findings suggest that SUI may have a differential effect on addictive behaviour. Claudio A. Naranjo, M.D., Clinical Pharmacology Program, Addiction Research Foundation and Departments of Pharmacology and Medicine, University of Toronto, 33 Russell Street, Toronto, Ontario M5S 2S1, Canada.

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RELATIONSHIP OF ADMITTING BLOOD ALCOHOL LEVEL (BAL) TO BENZODIAZEPINE (BZ) REQUIREMENTS DURING ALCOHOL DETOXIFICATION J.T. Sullivan and R.W. Swift There is interest in the prognostic value of an admitting BAL as a predictor of the severity of the subsequent alcohol withdrawal syndrome (AWS). An admitting BAL was taken on 114 patients admitted for alcohol detoxification. Subjects were not in AWS and usually exhibited mild signs of intoxication. Severity of AWS was determined by total BZ dosage (in diazepam equivalents DZE) provided during hospitalization. BZ was only given if they scored ~ 1O on a validated withdrawal scale. The mean (• age, BAL, BZ dose in DZE were 41• yrs., 222• 50• respectively. Relationship between BAL and BZ dose was not linear (r=.097). Rank correlation coefficients however revealed a relationship between BAL (in mg/dl), and BZ dose (Spearman's r=,21, p=.025) and also between BAL and age (p=.023) but not between age and BZ dose (p=.64). For subjects admitted with BAL400mg/dl (n=7) was BAL predictive of subsequent BZ dose (86% received > 60mg DZE). In conclusion there is a relationship between admitting BAL and subsequent BZ dose but only rarely is this of predictive value in individual cases. Department of Medicine, Brown University, Providence, Rhode Island 02908, U.S.A.

NALTREXONE: A POST-MARKETING SURVEILLANCE STUDY G. Bergonzini, A. F e r r a r t , C. F e r r e t t i , and L.A. Pini Since 1985 we have been evaluating the side e f f e c t s o f c h r o n i c a l l y o r a l l y administered naltrexone in heroin addicts (50 mg d a i l y f o r several months, 6 on average). As p r e v i o u s l y reported in p a r t , we have not observed any e f f e c t s o f naltrexone on the hepatic microsomal drug metabolizing system (by evaluating a n t i p y r i n e h a l f - l i f e ) , and we have i n v e s t i g a t e d the action of naltrexone on c a r bohydrate metabolism (absence of r e l e v a n t m o d i f i c a t i o n s of i n s u l i n and C peptide s e c r e t i o n , s l i g h t decrease of insulinemia, maybe due t o enhanced hepatic u t i l i z a t i o n ) . To date, the post-marketing s u r v e i l l a n c e study o f n a l t r e xone includes 91 p a t i e n t s (70 men and 21 women), aged 18-33 years (24.8 on average). The side e f f e c t s recorded in these 91 subjects are: orotractedabstinence syndrome (41% of p a t i e n t s ) , headache (29%), less a p p e t i t e (27%) without r e l e v a n t change in body weight, g a s t r o i n t e s t i n a l d i s t r e s s (19%), hypertransaminasemia (15%), asthenia and drowsiness (10%), u r t i c a r i a (one p a t i e n t ) . I t is worth evaluating n a l t r e x o n e - r e l a t e d headache. In at1, 20 subjects were a f f e c t e d . Six (30%) presented with migraine w i t h o u t aura, while the remaining 14 (70%) had t e n s i o n - t y p e headache. In most p a t i e n t s headache occurred during the i n i t i a l phase of induction as the d a i l y dose naltrexone increase. I t often seemed t o be dose r e l a t e d and was not accompanied by changes o f beta-endorphin in the plasma. Department of C l i n i c a l Pharmacology, U n i v e r s i t y of Modena, Via del Pozzo 71, 41100 Modena, I t a l y

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INDEPENDENT QUALITY CONTROLS IN THERAPEUTIC TRIALS. ABOUT AN EXPERIENCE OF SEVENTEEN INDEPENDENT AUDITS OF CLINICAL INVESTIGATORS PERFORMED IN FOUR EUROPEAN MULTICENTRIC TRIALS. G. Lagier1, J-F. Bergmann2, F. Calvo1and C. Caulin2

CONCEPT AND EVOLUTION OF ~ ESSF3CrlhL D~UG LIST A.W.ELBOROLOSSY This is an attempt to explain the concept of the Essential Drug List (El)L) initiated by WHO to help developing countries chose and procure drugs needed far their health services within the constraint of limited financial resources . The problem of drug availability todeveloping countries is discussed as well as relevant factors such as manpower deficiency,lack of financial resources and other socioeconomic problems.Next the paper discusses how can WHO help developing countries to overcome such problems and obtain their essential drugs of the right quality at a reasonable price.In the third part the paper explains the proceedure followed by WHO in the preparation and revision of the EDL.The role of the National authorities is then explained if they are to get the maximum benefit from the F.DL and other services offered by WHO.The paper ends by giving examples to explain how drugs are included in the EDL and how such list is periodically revised and updated according to developments in drug therapy .

Strict methodology, good clinical practices and quality control are necessary in therapeutic trials, especially when multicentric. Independent quality control site visits (audits) aim to control the reality and quality of data collection. They are essential in the quality control procedures. Guidelines to such site visits are to assess : 1) the accordance of the investigator to the protocol (characteristics of the study centre, of patients included and the follow up); 2) the review of data collection (concordance of flow sheet with the clinical chart); 3) the relationship between the investigator and the promotor of the trial (on site visits, information transfers, monitoring). General format of a site visit (who, where, when ?) has to be specified. Although needed by the promotor, independent clinical audits of investigators have to be independent and scheduled in the protocol. Our experience of 17 audits of clinical investigators performed in 4 european multicentric trials (72 centres, 3300 patients), shows that they are well accepted and contribute to the quality of data collection. From now, they appear to be. necessary in France, especially in large multicentric therapeutic trials. Quality control site visits to the promoter may also certainly contribute to improve therapeutic trials and allow quality of the work done being recognised.

l Cfinical Pharmacology, H6pital Fernand Widal and 2Therapeutic Department, Hdpital Lariboisi#re, 75475 PARIS Cedex 10, FRANCE.

PP 06.10 A CLINICAL TRIAL (C.T.) DATA BASE IN SPAIN A.J.Carcas, M.A.S. Castro, M.J. Gonz~lez de Suso and F. Garcia-Alonso, Ministry of Health, Madrid, Spain. Since 1982 regulations have existed in Spain to control the conduction of C.T. with new medicinal products, requiring the prior approval of the study protocol by the Ethical Committee and the Regulatory Authority. In this context we planned to design procedures that would allow for the simple and sistematic evaluation and collection of relevant aspects in a C.T. protocol. This would in turn allow the design of a data base to record and anlyze, collectively or individually, the information thus obtained. A coded data collecting form was devised made up of 155 items divided into the following sections: 1. Basic identifying data; 2. Evaluation results; 3. Essential requirements (pre-clinical data); 4. Type of clinical trials; 5. Design considerations; 6. Ethical issues; 7. C.T. monitoring; 8. Statistical analysis; sections 1, 2 and 4 include descriptive items whilst the other sections also include analytic items. The data base was created Using an IBM compatible programme named SIGma. Searching and management of data can be performed with all of the records or just with those that fulfil some selected conditions. It is possible to establish conditions for any field and chain more than one using the logic operations AND/OR. Data are susceptible of statistical analysis without having necessity of temporary files. Conclusion: This system permits t h e use of the data collection form as a "check-list" for the evaluation of C.T. providing standarization amongst evaluators. Transferring the information to a computer file would enable us to value the main characteristics of the C.T. conducted in Spain and their variation in time.

PP 06.12 KNOWLEDGE AND ATTITUDE OF PRIMARY CARE PHYSICIANS ON ESSENTIAL DRUGS A. MUCHTAR Department of Clinical Pharmacology University of Indonesia School of Medicine Jakarta, Indonesia One hundred and thirty-nine physicians who just returned from primary health care service were asked to fill in a questionaire on essential drug concept (EDC) and its implementation. One hundred and eleven respondents (80%) disclosed that they did not understand EDC, although the majority of them were aware of activities of its implementation. Those who were already aware of the activities of EDC implementation stated the necessity of publishing not just the list of essential drugs, but also a concise information including the indication, duration of treatment, precaution, contraindication, side effects, and wrong use of each essential drugs. According to respondents, such kind of formulary should be distributed freely to every physicians in primary heaith care level.

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MAIN PROBLEMS AND OPPORTUNITIES OF PHASE IV

IMPACT OF FINANCIAL REWARDING ON THE MOTIVATION OF HEALTHY VOLUNTEERS TO PARTICIPATE IN CLINICAL TRIALS J. Bigorra and J.E. Bafios Clinical research in healthy volunteers remains a necessary step in the e a r l y development of new drugs. Several studies have been performed on t h e i r m o t i v a t i o n s to v o l u n t e e r , but the impact of f i n a n c i a l rewarding (FR) has rarely been s p e c i f i c a l l y addressed. The aim of t h i s survey was t w o f o l d : to examine the proneness of medical students to volunteer and to evaluate the importance of FR and o t h e r general details in healthy volunteers who had already p a r t i c i p a t e d in clinical trials. A specific questionnaire was given to each group and answered anonymously. Among the 239 medical students (mean age 21.7 y ) who completed the q u e s t i o n n a i r e , o n l y 2.9% had already v o l u n t e e r e d , 39.7% manifested t h a t t h e y never would p a r t i c i p a t e , 24.7% would do f o r scientific interest, 32.2.% f o r scientific interest and FR, and o n l y 4.2% f o r FR only. Eighty volunteers participating in phase I clinical trials (mean age 25.2 y ) answered the q u e s t i o n naire. FR was the main reason to p a r t i c i p a t e (90%) f o l l o w e d by c u r i o s i t y (6.3%). The FR a c t u a l l y received was considered adequate by most of the v o l u n t e e r s (83.7%) and compensated the time and the d i s c o m f o r t , The i n f o r m a t i o n provided by the i n v e s t i g a t o r s and the arrangements made to t r e a t any hazardous event were considered adequate (47.5%) or very correct (42.5%). Nearly a l l (93.8%) answered p o s i t i v e l y when asked about f u r t h e r p a r t i c i p a t i o n in the f u t u r e . The present r e s u l t s show t h a t FR is a v e r y important m o t i v a t i o n f o r h e a l t h y v o l u n t e e r s to decide to p a r t i c i pate in c l i n i c a l t r i a l s . A m a j o r i t y considered adequate the f i n a n c i a l rewarding and agreed w i t h the provided i n f o r m a t i o n and arrangements.

MULTINATIONAL EUROPEAN CLINICAL TRIALS AN UPDATED REVIEW

G. Bai@ (*), R Rondel (**), L. St~ru (***), E. Szapiro (***) We have recently reviewed risks and opportunities associated with designing and monitoring of Phase IV multinational clinical trials in Europe (Drug Inf. J., in press, 1989). Requirements and possibilities are still different in each European country, in spite of a clear move towards higher standards for monitoring and evaluation. This presentation will expand on that subject, taking into account the latest regulations and their foreseeable consequences. Particular attention will be paid to recently published documentation, including the new French regulations accepted by the French Parliament in December 1988.

(') F. Hoffmann-La Roche & Co. Ltd, CH-4002 Basle, Switzerland (**) L T.E.M. Ltd, West End, Wokin~ Surrey GU24 9PW,, England (***) L T.E.M., 93 avenue de Fontainebleau, 94270 Krernlin-Bic~tre, France

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Departamento M~dico. Qulmica Farmac~utica Bayer S.A., E-08029 Barcelona, and ~Departament de F a r m a c o l o g i a i Psiquiatria Universitat Aut6noma de B a r c e l o n a

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STUDY ON SELECTION OF V O ~ IN PHASE I TRIAL : EVALUATION OF S~RLM TRANSAMINASE VAIDE M. Kobayeshi, S. Arai, N. Yameda, T. Nishikawa, H. Shibata Purpose: In spite of normal value of liver function tests before administration of teat drug in phase I trial, abnormal data were observed in some cases after administration. Therefore, we studied which volunteers would give abnormal data of liver function teats (GOT, GPT and ~'-GTP) among placebo-receiving group. Subjects: Phase I Clinical Studies had been performed for 720 volunteers for 3 years in our division. One month and one hour before the first administration, conventional liver function tests were.given placebo. P~sults:Among t h e 61 placebo~ 9 cases showed abnormal liver function test values of GOT or GPT after administration. 5 cases out of the 9 abnormal group had obesity index over +10%. On the other hand, only 7 cases out of the 52 normal liver function group had high obesity index over +10%. Difference the two groups was siginificant (9(0.05). Value of ~-GTP showed 20 u(mesn) in the normal function group and 36 u(mean) in the abnormal liver function group(p<0.05). Normal range of ~-GTP is 6 to 60 u in our laboratory. All 9 cases with abnormal liver function test value showed GOT/GI~ ratio of less s 1.0 even within normal range of GOT and GPT at pre-check. 0nly 20% of normal function group and GOT/GI~ ratio of less than 1.0. Its difference was siginificant(P~0.05). Canclusion: In the selection of volunteers for phase I trial, following criteria should be filled. (i) GOT value is higher than GPT value, and both values are within normal rangea. (2) [-GTP value is less than 40 u. (3) Obesity index is below +10%.

INTERINDIVIDUALDATA-COMPENSATIONAND DEVIATION-AREAEQUIVALENTS:A NEWMETHODFQR ASSISTING DECISION-MAKINGWITH LOW NUMBERSOF CASESIN BIOMEDICALEXPERIMENTS Snhl. Susanne and Seifert. Wolf The evaluation of biomedical t r i a l s with healthy volunteers and low number@ of cases is complicated by marked inter-individual variances. The Ratio Value (RV), the ratio of the intra-individuai to the inter-individual variances, indicates wether i t would be better to use intra-individual reference ranges for the evaluation instead of so-called 'normal ranges'. This is the case with RV's of
Toe Division of Clinical Pharmacology, Kiteaato University Fast Hospital, 863-1 Asamizodai, Sagmr~hara, KANAgAWA

Only transformations 4 and 5 lead to RV's >i and thus to a compensation of inter-individual differences in level, The deviation area equivalent (AUCeg) as a measure of scatter can be consldered as the expression of the dynamics of a series of measurements,

Intra-individual reference ranges cannot be used, however, in clinicopharmacological t r i a l s when comparisons of independent groups are carried out. The purpose of this project was to transform original data in order to obtain RV'a->I so that inter-individual differences in level could be kept as small as possible and extra-experimental reference ranges can be made applicable beyond the groups they were derived from. From the data of two investigations with healthy young volunteers (n-18) under

placebo, appropriate new RV's for the day profile (DP) and for the day-today profile (DTD) were obtained by 5 different transformations (TI-5): TI: x~= Igx~ T2: X l : X . - X 1 T3:

x =x + lOO/x,

T4: x~ = x-n - ~ i n T5: x t = x . i 0 0 / ~ i . ,

Ratio Values on the basis of transformad original data

TI: Sodium

Potassium Uric acid

T2:

T3:

T4:

T5;

DP

DTD

DP

DTD

DR

DTD

DP

DTD

0.41

1.94

0.3

0.85

0.3

0m83 1 . 2 2 2.13

DP

DTD

1 . 2 2 2.13

0.52 1.02 0.38 0.8 0.38 0.8 1.18 1.62 1.1g 1.63 0.26 0.32 2.18 o.g5 2.01 0.g5 4.62 1.59 4.27 1.66

Bilirubin 0.34 Alc,Phosph. 0 . 0 7 gGT 0.02

0 . 9 9 0.44 0.53 0.48 0.53 1 . 5 6 1 . 7 3 I.B9 1.68 0.25 0 . 9 7 0 . 5 1 0 . 9 2 0 , 5 1 ],75 1 . 5 6 1 . 7 2 1.54 0.33 0.16 0.37 0 . 4 4 0 . 3 7 1 . 1 6 1 . 2 4 1.18 1.27

easily obtainable by the use of appropriate programs, where XiT = single transformed value. ~ - i x , r _ }OOi AUC.q = x , .

n

Conclusion: Through the reduction in the inter-individual variances and the subsequent forming of deviation area equivalents, on-line decision-making can be facilitated even in group comparisons with low numbersof cases. Humanpharmakologie I, Schering AG, MSlierstraBe 172. 1000Berlin 65

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USE OF MULTIPLE COMPARISONS IN JAPANESE THERAPEUTIC RESEARCH

ABSORPTION OF NIFEDEPINE FROM NOVEL ORAL AND SUBLINGUAL FORMULATIONS. M S Henderson, P Rachitzky, J McEwen. J A Clements

T. Ishigaki, Y. Ohashi The problem of "multiplicity" has been well recognized in the f i e l d of medical s t a t i s t i c s ,

and the use of a p p r o p r i a t e

s t a t i s t i c a l procedures such as multiple comparison techniques or repeated-measurements analysis is advocated in many s t a t i s t i c a l guidelines of medical journals. To grasp the present status of the art in Japan, we have surveyed the latest volumes of 2 Japanese leading journals for c l i n i c a l pharmacology :"Japanese Journal of Clinical Pharmacology and Thecapy"(Vol.15 through 19)and "Clinical Evaluation"(Vot.12 through 16). Of 244 original articles, 37 a r t i c l e s carried out comparisons among more than two groups or time periods and only 3 of them used analysis taking account of multiplicity.

The others used multiple

t - t e s t s or z 2 t e s t s .

In t h i s presentation, the detailed analysis of the survey is presented and the reasons why appropriate s t a t i s t i c a l procedures have not been used are i n v e s t i g a t e d .

Adalat and 2 novel formulations of nifedipine (N) were compared for bioavailability after oral and sublingual administration. 12 h e a l t h y volunteers took p a r t in a r a n d o m 6-way crossover study. A liquid drop formulation of N provided faster absorption than Adalat by both routes (Tma x f o r d r o p s 27 & 48 m i n v s T m . f o r A d a l a t 73 & 80 min for oral and su~ingual routes respectively). Bioavailability was higher after N drops than Adalat (AUC r a t i o = 1 . 3 0 after oral and 1.19 after sublingual). A powder formulation of N gave similar oral absorption to Adalat but delayed sublingual absorption (T_ a. 74 & 92 m i n r e s p e c t i v e l y ) . Bloavailabzlz[~ was similar to that of Adaldat by both routes. Overall, profiles from the drops were similar to Adalat whereas for the powder the delayed sublingual absorption probably occurred after swallowing of buccal contents. Inveresk Research International, Edinburgh E H 2 1 7UB, UK. L a b s Boi, B a r c e l o n a , S p a i n Drug Development Scotland, Dundee

NIPPON SYSTEXK.K., Research Data Management Dept. Tokyo Tatemono Shlbuya Bldg., 9-9, Shibuya 3-chome, Shibuya-ku, Tokyo 150, JAPAN

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CLINICAL TRIALS AND CLINICAL PRACTICE: DO DOCTORS USE THE SAME CRITERIA TO JUDGE OUTCOME? DM Chaput de Saintonge, GJ Crane, JR Kirwan. Doctors' judgments of what is a successful treatment outcome can be modelled using patient simulations. We have shown how these models could be used to improve the power and impact of clinical trials (Chaput de Saintonge DM et al Br J Clin Pharm 1988;26:355-362). But do doctors judge the success of trial outcomes in the same way as they judge their patients' progress? If not, the convincing power of trials could be compromised by the choice of inappropriate variables. We gathered 30 sets of clinical data from patients with rheumatoid arthritiS. Each provided values for i0 variables before and after treatment. Each data set w a s p r e p a r e d in two formats with an associated task. In the 'patient' format typewritten sheets represented data from individual patients, and the task was to judge the degree of improvement in disease severity. In the 'trial' format each data set was professionally printed and laid out as a summary report of a small uncontrolled clinical trial. The task was to judge the degree of improvement in the trial patients. 14 rheumatologists completed the two tasks on separate occasions. Their judgments were modelled using multiple regression analysis with the clinical variables as predictor variables. 'Patient' models explained a mean of 63% of the variance and 'trial' models 64%. Three doctors judged 'trials' as showing significantly less improvement than 'patients' and 4 the reverse. Wide variation was observed between both doctors ~ judgments and the models describing them. Aggregate models were constructed which weighted each judge's contribution in proportion to his consistency. The same 3 variables accounted for 85% of the variance in both formats. The outputs of the models correlated well (rs=0.95). Thus while individual doctors may judge patients and trials differently, the basis for the aggregate judgment of groups of doctors is very similar. London Hospital Medical College, Turner Street, London, El 2AD

URICOSURIC EF[ECT OF AMBRgXOL 3 B. Oosterhuis-1 , G. Nehmiz-l, P" J'G" Corneli~sen , P.B.M.. Zuiderwijk , H.J. ~euring , J.H.G. Jonkman , C.A.P.F. Su 2 and R.G.L. van Tol-. Clinical studies with ambroxol investigating doses up to 120 mg daily demonstrated improvement of bronchopulmonary symptoms. The aim of the present double-blind, dose-response study was to assess the effect on uric acid plasma and urine levels, the mode of action and the tolerability of ambroxol following oral administration at a dose range of 250 to lO00 mg daily. Forty-eight (48) healthy male volunteers were included in the study and were assigned at random to one of the following treatment groups: placebo, ambroxol 125 mg b.i.d., 250 mg b.i.d, and 500 mg b.i.d. The trial consisted of 3 pre-medication days (baseline values) and 5 medication days. Five days following withdrawal of the trial measurements were repeated in order to check whether levels had returned to the normal range. In addition, blood was sampled for determination of creatinine and hypoxanthine levels. Ambroxol induced a significant, dose-dependent, lowering effect on uric acid plasma levels (250 mg b.i.d.: 18-20%; 500 mg b.i.d.: circa 30~). The uric acid clearance was dose dependently increased, while no effect was observed on creatinine clearance. Furthermore, hypoxanthine plasma levels were not affected by ambroxol. No severe adverse events were reported and no drug induced alterations were observed in the clinical laboratory values. It is concluded that ambroxol has an uricosuric action following oral dosing in higher doses (250 mg-500 mg b.i.d.) and is well tolerated. Ipharma Bio-Research International bv, Assen, NL. 2Dep. of Medicine, Dr. Karl Thomae GmbH, Biberach, FRG. 3Dep. of Clin. Res., Boehringer Ingelheim bv, Alkmaar, NL.

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PP 06.21 A DOUBLE-BLIND

S ~ 3 D Y T O DETEI~MINE T H E E F F E C T O F

PHARMACOKINETICS AND METABOLISM OF A NEW INTRAARTICULAK LUBRICANT, POLYVIHYLPYRROLIDONE

DIFLD-NIS~L A N D P L A C E B O GIVEN PRIOR TO ORAL S U R G E R Y O N P O S T - O P E R A T I V E P A I N A N D ANALGESIC REQUIREMENTS P. B r o w n a n d D.R.

Mehlisch 100 patients were stratified into two equal groups: Group A (I or 2 impacted wisdom teeth extracted) and Group B (3 or 4 impacted wisdom teeth extracted). One-half of the patients in each group were randomly assigned under double-blind conditions 1O00mg diflunisal or placebo to be taken I hour prior to surgery as a single pre-operative dose only and then evaluated following surgery for 12 hours. 6 patients did not remedicate during the 12 hour period after pre-operative diflunisal versus I patient on placebo. These 7 patients were excluded from analysis which understandably biased this study against diflunisal. On average, of the patients who remedicated, those receiving pre-operative diflunisal remedicated approximately I hour later than those receiving pre-operative placebo (p 0001). On a scale of I to 10, the median pain intensity was 5 units in the diflunisal group and 6 units in the placebo group (p 0.01). The median difference in the time from end of surgery to remedication was 53 minutes for Group A (p 0.05) and 37 minutes for Group B (0.05 p 0.02). For each group, the median pain intensity was I unit lower for the diflunisal patients than for placebo patients (p 0.05; 0.05 p 0.2 for Groups A and B, respectively). Pre-eperative diflunisal reduces pestoperative dental pain. With a single 1000mg dose, effects may be somewhat more pronounced in patients having I-2 third molars removed than in patients having 3-4 third molars removed. Biomedical Research Group, Inc., 1500 W. 38th Street, #51, Austin, Texas, USA 78731

IPVP)

A. A, Matulis, U, H. Dadoniene .................................. Results of our experimental studies of PVP solutions adminisiraled intraarticulariy for local treatment of osteoarihritis ate presented. The purpose of the experiment was to de!ermine pharmacckineiic and Theologic properties of the preparation. We found by direct radiometry technique that the half-period of its elimination from the articular cavity is two days in case of low-molecular mass PVP given as a 2#% solution of the 20,000 D PVP and three days in case of middle-molecular PVP given am a i5% solution of the 30,000 D PVP. A complete elimination of PVP from the articular cavity occurs within five to six days in the first case ~nd six to seven days in the second one. The main part of PUP solutions is excreted through the kmdneys and liver: 44% and 5~%, respectively, with ~0% solution, and 4S~ and 58Z. respeciively, wiih !5~ solution. In six days, the radioactivity level of the organs examined ~ppyoaohes to background values, no cumulative effect having been recorded. The viscosity- an~ interferometry dale showed ihal !he Theologic properties, viscosity and condensability, fully depend on concentration and molecular mass of PVP, Delng of significance to the way of behaviour of such a preparation in ihe organism. The comparative analysis of PUP solutions is therefore considered rovidin# a deeper insight into cerlain ~harmacoineiic aspects of intraarticular use o~ lubricants.

~

Research Institute of Experimental and Clinical Medicine, Pozelos i8, ~33600 Vilnius, Lithuania, USSR

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DOSE RESPONSE OF PICENADOL IN POSTOPERATIVE PAIN AT FOURTEEN CENTERS D.J, G o l d s t e i n , R. L. B r u n e l l e and D. M. Zimmerman The e f f i c a c y and s a f e t y of s i n g l e oral doses of picenadol (5, 15, 30 and 60 mg), an o p i o i d a g o n i s t ( d - i s o m e r ) a n t a g o n i s t ( I - i s o m e r ) , was compared w i t h codeine (30 and 90 mg) and placebo in 590 p a t i e n t s w i t h moderate or severe p o s t o p e r a t i v e pain in a m u l t i c e n t e r , randomized, double-blind, parallel study. Pain i n t e n s i t y and r e l i e f were assessed f o r up to s i x hours f o l l o w i n g drug a d m i n i s t r a t i o n and adverse events were c o l l e c t e d . The mean Visual SPID and TOPAR scores and m u l t i p l e , comparison i n t e r v a l s (p=.O5) are presented below. Both 15 mg o f picenadol and 30 mg o f codeine were s i g n i f i c a n t l y more e f f i c a c i o u s than placebo f o r the 3-hour Visual SPID but not the 3-hour Visual TOPAR. The verbal scores were s i m i l a r but not aB s e n s i t i v e . The adverse experience p r o f i l e s o f the a c t i v e treatments were not s i g n i f i c a n t l y d i f f e r e n t from placebo. Single dose e f f i c a c y and s a f e t y o f 15 mg o f picenadol were comparable to 30 mg o f codeine.

ANTIPROTOZOAL ACTIVITY OF THE NEW ANTIBIOnc (MT81) AGAINST L eishmania donovani PROIVlASTIGOTF.SIN VITRO.

MEANS AND MULTIPLE COMPARISON INTERVALS

,oi T/ 20

> z

100 . . . . . . . . . . . . . . . g

0 2. . . . . . . . . . . . . . . . . . . . . . . . . .

50

Inhibition of growth of L.dono'gQtlJ promastigotes (Indian strain UR-S) cells in presente of MT81 in [iquid culture media was estimated. T h e oxygen uptake of L.doF[ovart[ suspension was measured in a Warburg respirometer Jn presence of known concentration of MT81. Glucose supported respiration was also measured. MT81 caused growth inhibition of cells in liquid culture medium in low cor~cer~ration (2 pgJml). Studies on kinetics of bxygen uptak9 by L. donovs cells in presence of MT81 revealed a significant (P / 0.001) respiratory inhibition. antiprotozoal activity of the new

Pharmacology Research Laboratory, Dept. of Pharmacy, ]adavpur University Calcutta- 700 052, India.

. . . . . . . .

30 90 5 IB 30

A new antibiotic (MT81) has been discovered in our laboratory from the culture media of Penicillium nigricans (Indian Patent No.156916). Chemical studies revealed its structure as a poiyhydrexy anthraquininane with a molecular formula of C 2H1807 and molecular weight of 594. The present communication dea~s with the antiprotozoal activity of MT81 towardsb.donovani promastigotes in culture.

The results vividly demonstrate the antibiotic (MT81).

T ,',--~_L

~O PLACEBO .k

T.Chatter}eeand M. Gupta.

50

30 90 B 15 30

60

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GCP-CONFORM PROCEDURES IN HUMANPHARMACOLOGY B. SchiJtt. W. Seifert The requirements to be observed in the performance of clinical studies are increasingly being specified by laws and decrees. These include the German Drug Law (AMG), the Declaration of the World Medical Association and the international directives concerning "Good Clinical Practices". These requirements apply to both content and form: - scientific quality inclusion of an ethics committee standardizedproceduses for easier reconstructibility. The realisation of these requirements in the work of our Human Pharmacology Department using commercially available standard software is described below. The 19rocedure in the plznnln~,, performance and evaluation of the studies is laid down m internal work specificat,ous. Use ts made of standard text modules for the study plan and for the information for volunteers. A parameter form permits a rapid overview of target parameters and their measurement times. All the methods available in the department are set out in a catalog containing a reference relating to the method, the limit values and a clear 4-digit identification. A detailed description of the methods is given in the corresponding SOP's (Standard Operating Procedures). Laboratory requirement cards and data acquisition sheets for the methods selected are automatically printed with the aid of the Symbios software program. The values measured are read into the program via an interface to the laboratory computer. All other data are entered manually. Limit-value overshoots and subsequent changes to data are logged both with automatic and manual data input. These protocols carrying a serial number are part of the data stock and permit the reconstruction of the data path from the individual data to the evaluation. After the input of the data, these can be recalled in graph and tabular form on a menu-controlled basis. It is possible to select the original data of one participant with all the treatments (intra-individual cornparis" on) or of all participants for one treatment (inter-individual comparison). The presentation can initiallybe on the screen and for the final evaluation on hard copy. This allows the course control, which is particularly important when new compounds are being applied for the first time, to be carried out in parallel with the performance of the study. Data overviews show missing values or limit-value overshoots. The requirements for standard procedures permitting the reconstructibility of the study also for inspection purposes are tberfore met. The automation of the data input reduces errors and also permits staff economies. The standard format of the documentation sheets facilitates the review of the data. A further evaluation by transfer to other programs presents no problems. The formal requirements are therfore met, staff can concentrate on scientific work and the cost-calculation for biomedical research is favorably influenced. Hamanpharmakologie I, Schering AG, Postfach 650313, D-1000 Berlin 65

PHYSIOLOGICAL DISPOSITION OF A REDOX-SENSITIVE COPPER COMPLEX WITH SIGNIFICANT LIPID SOLUBILITY. R.P. Maiekel~ I.D. Baerga and M.A. Green. A radionuclide generator, i.e., the zinc62/copper-62 system, has been suggested as a potential source for use in diagnostic imaging by position emission tomography (PET). Such a system would be useful for sites which lack an in-hospital cyclotron for radionuclide production if it could be utilized for PET imaging of specific organ blood flow, especially if a suitable lipid soluble moiety ~ontaining the copper were available. Copper (II) bis(N -methylthiosemiearbazone) [Cu(PTSM)] is highly extracted by organs such as brain and heart; prolonged retention of radiocopper occurs due to intracellular redox breakdown of the complex by sulfhydryl-containing moieties. The subcellular distribution of radiocopper was studied in brain, heart, and liver of rats following i.v. administration of Cu(PTSM) labeled with copper-67. At i0 minutes postdosage, subcellular fractions of brain prepared by homogenization and differential centrifugation showed 51%, 35%, 11%, and 3% of total brain radiocopper in the cell cytosol, cell debris + nuclei, mitochondrial, and microsomal fractions, respectively. A similar distribution was obtained when CufPTSM) was added to whole brain homogenate in vitro followed by differential centrifugation. When animals were killed 24 hours postdosage, the m~tochondrial fraction was somewhat elevated (18%) and the cell cytosol (38%) decreased. Distribution of Cu(PTSM) in the liver at i0 minutes after i.v. dosage was: cell cytosol (46%), cell debris + nuclei (25%), microsomes (17%) and mitochondria (12~), similar to the distribution obtained 10 minutes after i.v. administration of Cu-citrate. Thus, the i.v. administration of tracer Cu(PTSM) followed by intracellular redox degradation appears to result in entrance of Cu into the normal cellular pools for copper ions. School of Pharmacy and Pharmacal Sciences, Purdue University, West Lafayette, Indiana 47907, USA.

-

-

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Withdrawn

LOW-DENSITY-LIPOPROTEIN FOR ~ I N G OF LIPOPHILIC DRUGS TO MALIGNANT CELLS. S. Vitols, G. Gahrton, M. Masc2/elier, C. Peterson, Mats 'Rudlln~, K. S~derber~. Low-density-lipoprotein (LDL) is the major cholesterol-carrying lipoprotein in h~m~n plasma and is delivered to cells by receptor-mediated endocytosis. Previous studies have shown that h~nan leukemic cells and certain solid ttmDurs have higher LDL-receptor activity than the corresponding normal cells or tissues. LDL has therefore been proposed as a drug carrier for anticancer agents. The present studies were performed to further elucidate the possibilities to use LDL as a drug carrier in the treatment of malignant disease. Hesults: Long-chain fatty acid derivatives of anthracyclines and a lipophilic alkylating agent (WB 4291) were incorporated into LDL. The drug ;-LDL complexes showed different in vivo stabilities after i.v. injection in animals. The type of fatty acid seems to be crucial for the fate of the LDL-incorporated anthracyclines. Balb-C mice with experimental leukemia were treated i.p. with WB 4291-LDL. 40% of the treated animals were long time survivors while all in the control group died within two weeks. The binding of 125I-LDL to crude tumour hcxnogenates of htm~n pancreatic and gastric carcincmas was in several cases very high. In vivo studies on 10 patients with acute leukemia showed that the radiolabeled LDL injected i.v. accumulated progressively for 12-30 hours postinjection in the leukemic cells. The uptake of radioactivity correlated well with the LDL-receptor-determinations on leukemic cells performed in parallel in vitro. Postmorten tissue biopsies frcm one patient shewed that the adrenals and the liver were the two organs which acctm~lated most radioactivity. Department of Clinical Pharmacology, Karolinska Hospital, 104 01 Stockholm, Sweden.

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PP 06.29 CONTROLLED RELEASE OF INDCMETHACIN FROM SOFT CONTACT LENS Jeffrey Grove, Claude Bunel*, Jean Claude Meslard*, Jean Pierre Vairon* and Bernard Plazonnet Centre de Recherehe, Merck Sharp & Dohme-Chlbret, Riom, Prance *Laboratoire de Chimie Maeromnl%culalre Universlt% de Pierre & Marie Curie, Paris, France. The sustained release of eo-valently bound Indomethacin from soft contact lens was followed over 7 days in albino rabbits. The lens were designed to release about i0 ~g of Indomethacin/day. The lens were hydrated with saline overnight and placed in both eyes of albino rabbits. The animals were subsequently sacrificed at 0.5, i, 2, 4, 6, 24, 48 and 72 hours and 7 days post- administration. Cornea, aqueous humor and iris + ciliary body were sampled for drug assay by HPLC with fluorimetrlc detection. Corneal concentrations increased slowly to a maximum of 2.24 pg/g at 6 hours. The corresponding values for aqueous humor and iris + ciliary body were 0.12 pg/ml and 0.07 pg/g at 4 hours post-adminlstration. Steady-state concentrations were then attained between days i and 7 in the cornea, ranging from 0.57 to 0.93 pg/g. Corresponding values for aqueous humor were 0.02 - 0.05 pg/ml and iris + ciliary body were 0.05 - 0.07 pg/g. These data indicate an initial release of loosely-bound Indomethaein during the first few hours. Thereafter ocular concentrations declined and by 24 hours a steady state was attained which was maintained up to 7 days later.

PP 06.31 EFFECT OF Q ~ I N E (Q), CIMETIDn~E (C) AND PENTOBARBZTAL (P) ON ~ DISI~3SITION OF NIFf~)IP~ (NlV), S P A R ~ (SP) AND HEP}IEI~TOIN (HP) AS.~SSESSEDBY A 'COCKTAIL APPROACH' JHM Schellens~ H Ghabrial~ GR Wilkinson and DD Breimer In 2 experiments the effect of enzyme inhibition, by Q and C, and induction, by P, was studied using the 'cocktail' of NF, SP and MP. The 'cocktail' of the first study also contained antipyrine. In the first study 15 healthy subjects (including 4 poor metabolizers [PM] of SP and 4 of MP) received the 'cocktail' without pretreatment, after P induction and again during C treatment. In the 2nd study i0 healthy subjects (including 1 P M of SP and 1 of MP) received the 'cocktail' without pretreatment and after intake of Q. Concentrations of NF, pyridine metaholite M-O, SP, dehydro-SP (DHS) were determined in plasma and M-I (ester hydrolyzed M-O), SP, DHS and 4-hydroxy-MP (OH-MP) in urine. Clearance (CL) of NF had increased 270% after P and decreased 33% after C. It was not significantly influenced by Q. AUC of M-O and urinary excretion of M-I had also decreased after P, but they were unaffected after C. AUC of M-O had decreased significantly after Q by 51%. Neither extensive metabolizers (EM) nor PM's of SP and MP were sensitive to P treatment. CL of SP was reduced by 55% in EM's and 59% in PM's after C, but metabolic ratio SP/DHS (MR) in urine was hardly influenced. CL of SP was reduced after Q from 979• to 341• ml/min. AUC of DHS had decreased from 553• to 56!89 ng.h/ml after Q. Formation clearance of DHS after Q was almost completely abolished. MR of all EM'a of SP had increased after Q and 2 EM's became PM'a temporarily. No effect of Q was found on urinary excretion of OH-MP. P, C and Q differentially affected the disposition of NF, SP and MP, probe drugs for characterization of the activity of the cytochrome P-450 system. The 'cocktail' approach seems to be feasible to assess induction and inhibition of the metabolism of model substrates simultaneously. Division of Pharmacology, Center for Bio-Pharmaceutical Sciences, POBox 9503, 2300 RA Leiden, The Netherlands Dept Pharmacology, Vanderhilt University, Nashville, USA

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PERCUTANEOUS ABSORPTION OF ACITRETIN C. Surber, K.-P. Wilhelm, D. A. Berman and H.I. Maibach Acitretin, a synthetic aromatic retinoid and the main active metabolite of etretinate, offers many potential benefits in the treatment of psoriasis and other keratinization disorders (J. M. Geiger et al., Curr. Ther. Res., 35. 735, 1984). Despite acitretin's pharmacokinetic advantage of beinig rapidly eliminated, this compound shares etretinate's toxicologic profile. These side effects make a topical form of acitretin with few or no systemic side effects desirable. To further characterize the therapeutic potential of topically delivered acitretin, we quantitively assessed its percutaneous absorption in nine healthy human volunteers using a topical, radiolabeled acitretin formulation. We found that a 24 hrs topical administration of a saturated acitretin isopropylmyristate formulation by occlusive dressing resulted in drug concentrations of 155 n g / g r (punch biopsy), 358 ng/gr (shave biopsy), 3796 ng/gr (suction blister skin), and 86 n g / g r (suction blister fluid), obtained by extraction of the respective specimens. Analysis of a 14 days collection of urine and feces from these subjects revealed no detectable drug levels9 These results suggest that topical delivery of acitretin renders skin concentrations which exceed those reported after oral administration of etretinate (O. Rollmann et al., Br. J. Dermatol. !09, 439, 1983) without achieving significant systemic drug concentrations. University of California San Francisco, School of Medicine, Department of Dermatology, San Francisco, CA 94143-0989, U.S.A.

DEBRISOQUINE OXYDATIVE METABOLISM PHENOTYPING : COMPARAISON OF A SHORT (3h) VERSUSSTANDARD (Sh) URINE COLLECTION TIME PERIOD D. Gangji , B. Noyelle, S. Bucquoye, P. F i f i l l s . Oxidative metabolism phenotyping is used in pharmacogenetic of drug response and to study genetic control or s u s c e p t i b i l i t y to certain diseased states. Debrisoquine (D) hydroxylation polymorphism is determined from the metabolic r a t i o of D/4-OHD in urine obtained over 8 h following an oral dose of D. D hydroxylation segretates into d i s t i n c t phenotypes : extensive (EM) and poor (PM) metabolizers. Metabolic r a t i o greater than 12.6 indicate PM phenotype and are found in 5-9 % of caucasian populations. A shorter urine c o l l e c t i o n time period would be more convenient for large populations or patients studies. We therefore compared the D/4-OHD metabolic r a t i o obtained a f t e r 0-3 and 0-8 h urine collections on two d i f f e r e n t occasions. We studied a group of 35 healthy volunteers not previously phenotyped and 4 poor metabolizers (D/4-OHD > 12.6). All subjects collected on two d i f f e r e n t occasions, a 0-3 and 0-8 h urine a f t e r a i0 mg D (Declinax R) oral dose. D and 40HD analysis was simultaneously achieved by HPLC. Among the 35 subjects two were i d e n t i f i e d as PM. A l l subjects i d e n t i f i e d as PM or EM by the 0-8 h test were s i m i l a r l y segregated by 0-3 h t e s t . There was a good correlation (r : .91) between the metabolic r a t i o determined a f t e r 0-3 and 0-8 h f o r the 39 subjects suggesting that the short urine c o l l e c t i o n time period may be used for further population studies. C l i n i c a l Pharmacology Unit, HSpital Erasme, School of Medicine, Universit6 Libre de Bruxelles, 808 route de Lennik, 1070 Brussels, Belgium

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A MIXTURE MDDEL OF DRUG PDLYMORPHISM P.LledO, S.H.D.Jacksen, A.Johnston & R.M.Pearson

QUINIDINE POTENTLY INHIBITS THE 2-HYDROXYLATIONOF IMIPRAMINE AND DESIPRAMINEBUT NOT THE DEMETHYLATIONOF IMIPRAMINE K. Brosen and L.F. Gram The 2-hydroxylation of imipramine and desipramine is cata]yzed by the sparteine/debrfsoquine oxygenase, P45Odb1, whereas demethylation of imipramine is catalyzed by a different P450 (I). Quinidine is a potent inhibitor of P450dbl function in v i t r o and in vivo but may inhibit other P450's as well. In two separate periods, each lasting 12 days, 6 healthy extensive metabolizers (EM) daily took 200 mg of a sustained release preparation of quinidine sulphate (Kinidin Ouretter). On day 4 in the f i r s t period each volunteer took a single oral dose of 100 mg imipramine HCL (Tofranil) and in the second period, 100 mg of desipramine HC] (Pertofran). Blood samples were drawn at

Graphical methods are generally employed to provide evidence for drug pnlvmorphism by demonstrating muitimodalitv in the distribution of the metabolic ratio (MR) (parent drug: metaboHte), with the antimodes corresponding to the breakpoints of the different metabolizing groups. An alternative approach (Evans,D.A.P. et at.,J.Med.Genet. 20, 321,1983; MitcheH,S.C. et aL,Br.J.Ciin.Pharmac. 18,587,1984; Lled6,P. et al.,Proeeedjngs BPS,5-7 Apr. 1989) is based on the assumption that the (log) MR is distributed as mixture of normal components. Using 8ayes' theorem, individuals are allocated to that component for which, given the MR, the probability of belonging is greatest. Maximum likelihood estimates (MLE) of the parameters of the distribution are obtained using a straightforward iterative algorithm (e.g. the EM algorithm, MeLachtan,G.J. & Basfard,K.E.,"Mixture Models: Inference and Clustering AppJications",N.Vork,M.Dekker,1988). A fundamental question is how many metabolizing groups there are. Since the number of components in a mixture is not necessarily equal to the number of modes in the distribution, tests for ~he number or modes are not appropriate. Unfortunately, the likelihood ratio test does not have the expected ~C-~ distribution. However, this test can be easily "bootstrapped" by generating random samples from the MLE of the assumed distribution function (McLachian g 8asford, op.cit.). We have applied the above techniques to three different data sets of debrisoquine urinary MR from white Caucasians (Siean,T.P.,unpublished

PhD dissertation,University

of London,

1980; Steiner,E. et aL,Clin.Phamac.Ther.44,431,1988; Lled6,P. et ai.,np.cit.). The results suggest that the usual classification into two metabolizing groups is probably insufficient. Mixtures may be erroneously found if the distribution is skewed. Log-transforming the data usually removes skewness, but we have also considered the more general Box-Cox transformation (3.R.Statist.Soc.B,26,211,1964). Department of Clinical Pharmacology, St.Barthoiomew's Hospital, London EC1A 7BE, UK.

regular ~ntervais f o r 9 days, and imipramine and i t s metabolites were assayed in plasma by q u a n t i t a t i v e thin layer chromatography. The t o t a l clearance (CL) and imipramine CL via demethylation and other pathways was calculated. The values (means • s.d.) obtained in the same EM and in 6 poor metabolizers (PM) without quinidine (-q) (1) are used as controls.

Imipramine CL( l min-1) Desipramine Total 6EM (+q! 1.4 + 0.9 6EM (-q) 2.2 + 1.1 6PM (-q) 1.4 • 0.2 EM (+q)vs. EM (-q) N.S.

Demethyla- Other tion pathways 1.2 + 0 . 8 1.5 _+ 1.2 1.1 _+ 0.3 N.S.

0.2 + 0.2 0.7_+ 0.3 0.3 + 0.2 p
Total 0.2 + 0.1 1.2 • 0.3 0.2_+ 0.1 p
(1) Brosen et al (1986). Clin Pharmacol Ther 40:543-9 Department of C l i n i c a l Pharmacology, 0dense University, J.B. Winslowsvej 19, DK-5000 0dense, Denmark

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EFFECT OF DIAZEPAM ON THE DEBRISOQUINE AND MEPHENYTOIN L~fDROXYLATION PIIENOTYPE E. Spina, A.L. Buemi~ E. Sanz, L. Bertilsson Recent studies indicate that the metabolism of diazepam is related to S-mephenytoin but not to debrisoquine hy-

BIMODAL DISTRIBUTION OF REDUCED HALOPERIDOL (RHAL)/ HALOPERIDOL (HAL) RATIOS AMONG JAPANESE PSYCHIATRIC PATIENTS AND HAL REDUCTASE IN HUMAN RED BLOOD CELLS T. Inaba(ll, T. Someya(2), S. Takahashi(2), M. Shibasaki(2) W. Kalow(1), S.W. Cheung(3) and S. W. Tang(l,3).

droxylation phenotype (L. Bertilsson et al., Clin Pharmacol Ther, in press). Moreover diazepam inhibits the hydroxylation of S-mephenytoin in vitro in human liver microsomes (T. Inaba et al., Drug Metab Disp, 13, 443, 1985). We investigated the effect of diazepam treatment on the debrisoqtLine and mephenytoin hydroxylation phenotyping tests. Nine male patients were phenotyped with debrisoquine (10 m~ p.o.) and mephenytoin (I00 mg racemic p.o.) before and during diazepamtreatment at a daily dose of i0 or 15 mg. Gas chromatographic methods were used to measure debrisoquine, 4-hydroxydebrisoquine, S- and R-mephenytoin in the 0-8 hour urine. The debrisoquine metabolic ratio and the S/R enantiomeric ratio of mepheny~oin did not change significantly during diazepamtherapy. We can thus conclude that the debrisoquJ~le and mephenyrain hydroxylation tests can be performed in diazepam treated patients. It is likely that therapeutic doses of diazep~n are too low to inhibit the hydroxylation of Smephenytoin in viva. Istituto di Far~acologia, Facolt& di Medicina e Chirurgia~ Universit& di Messina, Piazza XX Settembre 4, 98100 Messina, Italy

Haloperidol is one of the most commonly prescribed neuroleptics, and its plasma levels are known to vary widely between individuals. Reduced haloperidol is one of the HAL metabolites and was found in plasma from patients on chronically administered HAL. We measured plasma levels of RHAL and HAL in 45 Japanese patients and the following points became apparent. The mean RHAL/HAL ratio (n=45) was 0.57 • 0.38 (SD) (range: 0.i2.1). The distribution of individuals in relation to RHAL/HAL ratios had an apparent bimodal pattern and 0.7 appeared to be the antimode. There were 8 individuals (18%) who had high. R HAL/HAL ratios, while 37 had ratios (82%) lowere than 0.7. Secondly, RHAL/HAL ratios remained constant in a given subject indicating small intra-individual variability compared to the variability between individuals. A site of HAL reduction is the liver. Human red blood cells (RBC) from healthy subjects (n=8) reduced HAL to RHAL in the presence of NADPH. Inhibitors of the RBC reaction were the same as those for the HAL reductase present in human liver suggesting that RBC may serve as a valuable tissue to estimate the drug reductase activity in humans. i) Department of Pharmacology, University of Toronto, Toronto, Canada. 2) Department of Psychiatry, Shiga University of Medical Science, Otsu, Japan. 3) Psychopharmacology Unit, Clarke Institute of Psychiatry, Toronto, Canada.

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THE PHARMACOKINBTICS OF MELATONIN IN EXTENSIVE AND POOR METABOLISER8 OF DEBRISOQUINE T.Edeki, P.Francis, M. Stalteri, R. Silman and P.Turner. Melatoni n is an indolic hormone secreted by the pineal gland and metabolised at the carbon 6 position to form 6-hydroxymelatonin (Kopin et al 1960, Biochim. Biophys. Acta 40:377-378). The metabolic control of indoramin, another indolic compound which is hydroxylated at the carbon 6 position, cosegregates with that of debrisoquine (Pierce et al 1987, Bur J Clin Pharmacol 33: 59-65)~ We considered of it interest to investigate a possible influence of debri$oquine genetic polymorphism on the pharmacokinetics of melatonin. 9 subjects (5 females), aged 20-30yrs and weight 60-81 kg, made up of 5 extensive (EM) and 4 poor (PM) metabolisers of debrisoquine, matched for age and sex, were given 50mg melatonin capsules orally with 50mi of water. Blood was collected before and at 20, 30, 40, 60 and 90 minutes and 2, 3, 4, 5, 6 and 8 hours. Analysis was by RIA. Th~ elimination of melatonin from blood showed a moanor biphasic elimination with first-order kinetics. The pharmacokinetic parameters of EM and PM compared by students t test showed no significant differences for AUC to infinity and Cmax 250890 + 197480 vs 126400 + 372131 pg/ml.h and 157450 + 125540 vs 127830 + 117530 pg/ml respectively. There was however a significant difference ( p < 0.05) in the terminal elimination half-lives 1.12 ! 0.5 vs 3.07 ~ 1.27 hours respectively. These results do not clearly demonstrate that the control of melatonin metabolism cosegregates with that of debrisoquine. This may be due, at least in part to wide intersubject variation in melatonin absorption. To clarify this further, we will proceed to a more direct measurement of melatonin metabelites. Department of Clinical Pharmacology, St. Bartholomew's Hospital, London EC IA 7BE.

CIGARETTE SMOKING AND DEBRISOQUINE OXIDATION PHENOTYPE J.Cobaleda, A.LLerena, J.Benftez. Department of Pharmacology, Medical School, University of Extremadura, Badajoz, Spain. The most common environmental factor known to induce the metabolism of drugs is cigarette smoke. To see wether smoking could influence the debrisoquine oxidation capacity we decided to phenotype healthy volunteers, both while smoking and after quiting smoking. Therefore, after obtaining their informed consent, 19 healthy smokers (11 males and 8 females) ranging in age from 20 to 65 years (mean 32.9!=13.5 years old) were recruited to participate in this study. All of them had been smoking 10 cigarettes or more for at least 5 years (mean 21.9i-_9.9cigarettes/day). The debrisoquine oxidation phenotype for all subjects was determined by-the method described by Lennard et al. They were phenotyped during smoking and 1 to 3 months after cessation of smoking. Three subjects (2 females and 1 male) were poor metabolizers (I'M) and remained so after cessation of smoking. The other 16 subjects were fast metabolizers ant they also remained so after cessation of smoking. Howewer, there was a slight reduction of the debfisoquine metabolic ratios after cessation of smoking in all but three of the fast metabolizers (mean 0.68+_0.29 during, and 0.58-+0.29 after cessation of smoking). This difference was statistically significant (9=0.01). These results suggest that although smokingdoesn't seem to change the classification of a subject as poor or extensive metabolizer it could modify the MR to a certain extent and this should be kept in mind when phenotyping populations including smokers. 1.- M.S.Lermard et al. J.Cromatogr 133:161-165, 1977.

Supported in part by grants CAICZT PB85-0154 and F1Sss 87/1434. JesOs Cohaleda Polo. Faeultadde Medtelna.Av.de Elvas s/n. E-06071 BadaJoz. Spain.

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DEBRISOQUINE OXIDATION PHENOTYPE AFTER OVARIOTOMY

RELATION OF ACETYLATOR AND DEBRISOQUINE HYDROXILATOR PHENOTYPES TO GASTRIC AND COLON CANCER N. Drakoulis, I. Janicke, M. Cuprunov, S. Minks, I. Roots Various earlier studies revealed a relationship between certain genetic traits in foreign compound metabolism and individual cancer susceptibility. Thus, the prevalence of high and low activity phenotypes of N-acetyltransferase and cytochrome P-450 debrisoquine 4-hydroxylase activity was evaluated in gastric and colon cancer patients as well as in 383 reference patients without any carcinoma. Metabolic ratio (MR) of debrisoquine (D)/4-OH-D was determined in 5-hrs urine samples after application of 5-10 mg D. MR-values > 12 represent homozygous poor metabolizers (PM). Acetylator phenotype was determined by the molar ratio of 5-acetylamino-6-formylamino-3-methyluracil (AFMU) and l-methylxanthine (iX) in urine after caffeine intake.Gastric cancer patients (n=184) showed a significant underrepresentation of PMs (4.3%) as compared to reference patients (10.7%, p=0.006). This underrepresentation seems to exist only in the so-called intestinal type according to the histological classificition of Laur~n (p=0.0009) and not in the diffuse type. Interestingly, patients with exorbitantly high debrisoquine 4-hydroxylase activities (MR < 0.2) and intestinal type have more often blood group 0 (p=0.047) than expected. Slow acetylators are significantly overrepresented in both histological forms: 63.3 % in intestinal type, p=0.03, and 65.8 % in diffuse type, p=0.01, vs 52,0 % in 383 references. In contrast, ii0 colon cancer patients showed no significant overrepresentation of either acetylator phenotype. The differential distribution of certain genetic traits such as hydroxilator status and blood groups among intestinal and diffuse type of gastric cancer might support the notion that both types represent different nosological entities. Among patients with colon cancer no overrepresentation of fast acetylators was found in contrast to reports of other authors. Acetylator and hydroxilator phenotypes seem to constitute genetic host factors for certain types of cancer. Institut ffir Klin. Pharmakologie, Klinikum Steglitz, Freie Universit~t Berlin, Hindenburgdamm 30, D-1000 Berlin 45

A.LLerena 1, A.M.Pner~01 , C.Martfnez 1, M.J.Valdivielso 1, J.Cobaleda 1, ~l,Benftez 1, r

2, J.Arbues 2. Departments of Pharmacology 1 and

Gynecology2. Medical School. University of Extremadara, Badajoz, Spain. The oxidative hepatic metabolism of some substrates in the rat is sex-dependent. In the DA rat the female is poor metabolizer (PM) of debfisoquine while the male is extensive metabolizer (EM). The origin of this sex difference has been suggested to be due to some hormonal effects on the hepatic P-450 system. The present study was underlaken to investigate wether similar hormonal effects could exist in humans. For this we have studied 16 women before and after ovariotomy for the treatment of uterine leiomyoma that were otherwise healthy. They ranged in age from 36 to 50 years (mean 45+_3.7 years). None of them was smoker. After obtaining their informed consent they were phenotyped by the method of Lennard et al (1) in two ocasions: I) in the week before ovm'iotomy, II)within the first two weeks after ovariommy. One woman was PM and remained so after ovariotomy. The other 15 women were EM and they also remained so after ovariotomy. However, there was a slight reduction of the debrisoquine metabolic.ratio in all but four of the EM and this difference was statistically significant (9---0.04, two ways Anova parametric test). These results confirm the interspecies differences with regard to the P-450 dependent debrisoquine oxidation. However, the slight differences found deserve further investigation. 1.- M.S.Lermard et al. J.Cromatogr 133:161-165, 1977.

Supported in part by grants CAICYT PB85-0154 and FISss 87/1434. Adri~. LLerena. Facultad de Medlcina.Av.de Elvas s/n. E-06071 Badajoz. Spain.

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GENETIC POLYMORPHISM OF N-ACETYLTRANSFERASE:

IMPAIRED HYDROXYLATION OF CHLORPROPAMIDE IN POOR DEBRISOQUINE METABOLIZERS J. Kallio, R. Huupponen and K. Pyykk~ The pharmacokinetics and the ratlo of unchanged chlorpropamide (CP) to its hydroxylated metabolites (metabolic ratio) after slngle oral 250 mg dose of CP was studied in six extensive and five poor metabolizers of debrisoquine. Ammonium chloride (36-38 g) was given orally during 96 h to acidify the urine and to make the elimination of the parent drug dependent on metabolism only. The concentration of unchanged CP in serum was determined with HPLC. The metabolic ratio of CP in urine was determined with GC-MS during the ist and 4th days of the study. On the 4th day, the metabollc ratio of CP in urine was significantly higher in poor metabolizers of debrisoquine (0.71+0,37) than in extensive metabolize~s (0.25+0.~4; p=0.017, Mann-Whitney U-test). However, The concentration profile and the pharmacokinetic parameters of the unchanged drug in serum were similar in both phenotypic groups. As the 2-OH-chlorpropamide is the major metabolite of CP in urine, it is suggested that other metabolic reactions of CP compensate for the impaired hydroxylation in poor debrisoquine metabolizers. Departments of Pharmacology and Clinical Pharmacology, University of Turku, Kiinamyllynkatu i0, SF-20520 Turku, Finland

ENZYME A C T I V I T Y AND CONTENT IN LIVER BIOPSIES CORRELATES WITH A C E T Y L A T O R PHENOTYPE DETERMINED WITH CAFFEINE D.M. Grant, M. Eichelbaum and U.A. Meyer V a r i a t i o n in the m e t a b o l i s m of many clinically useful arylamine drugs is related to differences in liver arylamine N-acetyltransferase (NAT) activity. A simple test using caffeine (Grant et al, Br J Clin Pharmac 17, 459) is safe, practical and sensitive in determining the acetylator phenotype. The goal of the present study was to compare caffeine acetylation phenotyping results with newly developed biochemical and immunological m a r k e r s for liver NAT activity and content. Liver wedge biopsies were obtained from 14 patients who had previously supplied urine samples after caffeine intake, and acetyl CoAdependent NAT activity in cytosols from the l i v e r samples was measured using four different acceptor amine substrates. The in vivo urinary A F M U / I X ratio after caffeine administration correlated very highly with in vitro NAT activity (r=0.98). Moreover, Western blots using an antiserum raised against purified human liver NAT showed a decrease or absence of a protein of Mr 31 kDa in cytosols from slow acetylators when compared with that present in rapid acetylators. Our results provide a direct validation of the caffeine test as a measure of liver NAT activity in man, and suggest a decrease in enzyme protein content in liver as a mechanism for defective drug acetylation. Department of Pharmacology, Biocenter, U n i v e r s i t y of Basel, 4056 Basel, Switzerland.

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METABOLIC CORRELATION BETWEEN TRIMETHADIONE AND ANTIPYRINE, TWO INDICATOR DRUGS USED FOR ASSESSING OXIDATIVE DRUG-METABOLIZING CAPACITY IN H U M A N S E. Tanaka z and K. Nakamura 2 To ten healthy male volunteers trimethadione (TMO;4 mg/kg) and antipyrine (AP;500 mg/man) were administered alone or concomitantly to determine whether the m e t a b o l i s m of TMO and AP would be mediated by the same or closely related forms of the cytochrome P-450 system. When the two drugs were administered alone or coadministered, clearance (CL) and half-life (tlj2) of TMO and AP did not significantly alter the disposition of either drug. Good correlations between CL and tzl 2 of TMO and AP were shown (alone: r=0.755 and 0.623, respectively; coadministerd: r=0.771 and 0.503, respectively). Excretion of AP and its main metabolite (% of dose) and clearance for production (CLm;ml/min) of AP metabolites after AP was administered alone were net significantly different from those after TMO and AP were .coadministered. When the two drugs were administered alone or coadministered, the correlation between CL of TMO and excretion of 3-hydroxymethyl-3-nonantipyrine (NORA) were good (alone: r=0.734, coadministered: r=0.749). Correlations between CL of TMO and CLm of NORA when TMO and AP were administered alone or concomitantly were 0.762 and 0.772, respectively. These findings suggest that TMO m e t a b o l i s m and the formation of NORA in healthy subjects is mediated by reasonably related form(s) of the cytochrome P-450 system. ~Institute of Community Medicine and 2Institute of Clinical Medicine, U n i v e r s i t y of Tsukuba, Tsukuba-shi, Ibaraki-ken 305, Japan

XbaI-RFLPs ASSOCIATED WITH THE POOR METABOLIZER PHENOTYPE OF THE SPARTEINE/DEBRISOQUINE POLYMORPHISM A. Gaedigk and M. Eichelbaum The sparteine/debrisoquine-polymorphlsm is a clinically important genetic defect of oxidative drug metabolism affecting 6.5"/= of the German population. Two mutant alleles of the gene ceding for the synthesis of human cytochrome P-450db1, the isozyme responsible for this polymorphic oxidation, have been described recently (R.Skoda et al., PNAS 85,5240, 1986). Leucocyte DNA of 51 unrelated poor metabolizers (PMs) corresponding to a population sample of 765 individuals was examined by Southern analysis using Xbal restriction enzyme and dbl-cDNA. The RFLPs associated with the PM-phenotype described by Skoda et al. were 29/29, 44/44, 44/29, 44/11.5 and 29/11.5 kilobaae (kb) fragments. We found additional fragment patterns In our PMs: 11.5/11.5, 44/16 + 9, 29/16 + 9 and 29/9 kb. Whether the 16+9 and 9 kb fragments constitute other mutant alleles cannot presently been decided. Only 27.5% of the PMs are homozygous or heterozygous for 44 or 11.5 kb or reveal the 44/16+9 kb pattern. All other PMs carry at least one 29 kb f~gmant which also ocours in all extensive metabolizers. Thus the wild-type and mutant 29 kb allele cannot yet be discriminated by RFLP analysis. A hypothetical restriction map of a normal dbl-gene based on single and double digests of certain DNAs was designed by R.Skoda. The DNAs of our 11.5 kb homozygous individuals were digested with several restriction enzymes in order to test the map. The results indicate that a DNA deletion could be responsible for the occurence of the Xbal 11.5 kb fragment. This theory will be evaluated by cloning and restriction mapping of an appropriate genomic fragment of the 11.6/11.5 kb individuals. Supported by the Robert-Bosch-Foundation, Stuttgart. Dr. Margarete Fischer-Bosch-lnstitut f~r Klinische Pharmakologie, Auerbachstr. 112, 7000 Stuttgart 50/FRG.

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STEREOSELECTIVE PROPAFENONE DISPOSITION IN POOR AND EXTENSIVE METABOLISERS OF SPARTEINE A.S. Gross, D. Trenk, H. Kroemer, C.O. Maese, E. J~thnchen and M. Eichelbaum

PARACETAMOL METABOLISM IN CHINESE AND INDIANS IN SINGAPORE H.S. Lee~ T.Y. Ti and A. Hsu Our preliminary study (4th SEA/WP Regional Meeting of Pharmacologists 1985 p20) has indicated that significantly less paraeetamol sulphate conjugate was recovered in urine of Indians than Chinese. T h i s paper compares the 24 hour urine recovery of paracetamol and its metabolites between 24 Chinese and 24 Indian males. Their mean ages were 25.9 • 1.27y and 24.0 • 0.66y; mean heights, 169 • 1.18cm and 171.5 • 1.3cm and mean weights 59.1 • 1.27kg and 63.2 • 1.62kg respectively. 2 tablets of PANADOL | were taken after an overnight fast and 24 hour urine was collected and frozen until assayed. Estimation of paracetamol and its matabolites was done using HPLC method modified from Howie et al (J. Pharm. Pharmac. 29, 235, 1977) and Adriaenssens & Prescott (Br. J. Clia. Pharmac. 6, 87, 1978).

Propafenone is a Class lc antiarrhythmic drug, administered as a racemate, which is extensively metabolised. Formation of the primary metabolite 5-OH propafenone is impaired in poor metabolisers (PMs) of sparteine. R- and S-propafenone have similar activity on fast sodium channels, however the S enantiomer has additional ,3-blocking activity. During propafenone therapy PMs experience a higher incidence of side effects than extensive metabolisers (EMs). The present study was initiated to determine whether the pharmscokinetics of propafenone are enantioselective and to establish whether phenotyplc differences occur which in turn could influence the spectrum of side effects observed in EM and PM patients. Racemic propafenone HCI (150rag) was administered to eight young healthy volunteers (4EMs and 4PMs of sparteine). Blood samples were collected at timed intervals over 12 hours in EMs and 24 hours in PMs. Plasma concentrations of R- and S-propafenone were determined after formation of diastereomers with (R)-(-)-f-(fnapthyl-ethyl)ethyl isocyanate by liquid chromatography with ultraviolet detection. Plasma concentrations of both propafenone enantiomers were greater in PMs than in EMs (Cmax[ng/ml] PM R:210• S:284• EM R:38• S:66• In all subjects the concentration of S-propafenone was higher than that of the Renantiomer. S-propafenone AUC [hng/ml] was therefore greater than R-propafenone AUC in both PM (S:3366• R:2335• 1009) and EM (S:215 -+ 144 R:112 • 64) subjects. The half-life of both enantiomers was similar in each subject. The ratio of the concentration of Spropafenone to that of R-propafenone was similar in EM (S/R 1.77• and PM (S/R1.53-+0.30) subjects. The disposition of propafenone is therefore stereoselective in both EMs and PMs. No large difference in the degree of enantioselectivity is observed between the phenotypes. Supported by the Robed Bosch Foundation, Stuttgart. Dr. Margarete Fischer-Bosch-lnstitut f6r Klinische Pharmakologie, Auerbachstr. 112, D-7000 Stuttgart 50 / FRG.

PARACETAMOL AND ITS METABOLITES RECOVERED IN 24h URINE (% OF ADMINISTERED DOSE) Total G/S G S PA CYS Met recovered ratio Chinese Mean 4 9 . 3 26.3* 3.08 1 . 8 9 3.07 83.7 1.99 n = 24 sere 2.78 1 . 0 3 0 . 1 6 0 . 2 5 0.41 2.75 0.41 Indians Mean 5 4 . 9 21.1" 2.8 2.0 2.9 83.8 2.94 n = 24 s ~ 2.67 1.41 0.2 0.26 0.27 2.67 0.27 G = glucuronlde, S = sulphate, PA = paracetamol, CYS = cysteine, Her = mercapturic acid, *p
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PHENOTYPIC DIFFERENCES IN THE STEREOSELECTIVE DISPOSITION OF FLECAINIDE IN EXTENSIVE AND POOR METABOLISERS OF SPARTEINE C. Fischer, A.S. Gross, G. Mikus, R. Hertrampf, U. Gundert-Remy and M. Eichelbaum

S-MEPHI~IYTOIN HYDROXYLATION IN A SPANISH POPULATION. J. Reviriego, J. Benitez, L. Bertilsson, J. Cobaleda, A. Llerena, J. Rodriguez, E.J. Sanz, M.J. Valdivielso The polymorphic S-(4')-hydroxylation of the anticonvulsant drug mephenytoin was discovered by Ki~pfer et al (J. Pharmacol. Exp. Ther 218, 193, 1981). As it is the hydroxylation of S- and not R- mephenytoin that is affected, the urinary S/R ratio can be used to phenotype individuals after administration of the race~lic drug (Wedlund et al, Clin Pharmacol Ther 36, 773, 1984) . We have investigated the incidence of poor metabolizers (PM) of S- mephenlrtoin in 136 (61 males and 75 females) healthy, drugfree Spanish Caucasian subjects. After emptying their bladder, all subjects took one tablet of i00 mg of racemic mephenytoin (Mesantoin, Sandoz), at bed time. Urine was collected during two consecutive nights, 0-8 h and 24-32 h, after drug intake. The mephenytoin S/R ratio was determined by gas chromatography, with a Chirasil-Val capillary coltmtn. The minirm~n measurable S/R ratio was 0.05. In the total sample of 136 subjects, one had an S/R mephenytoin ratio higher than 1 in the urines of beth collection periods. He was considered to be PM of Smephen~rhoin (0.73%, with a 95% confidence interval of 0.0-2.1%). The other 135 subjects had S/R ratios <0.9 in the first collection period and all of them decreased to <0.25 in the second urine. These were considered to be extensive metabolizers (I~4), since S-mephenytoin is more quickly eliminated than the R-enantiomer in EFLs. The second night sanples clearly separated the two phenotypes from each other. Two of the EMs had a high S/R ratio of 0.86 and 0.88 in the first ttrine and a ratio of 0.14 and 0.22, respectively, in the second urine. These might be considered intermediate hydroxylators. Department of Clinical Pharmacology, Karolinska Institute, Huddinge University Hospital, S-141 86 Huddinge, SWEDI~q and Deparil~ent of Pharmacology, Faculty of Medicine, University of Extremadura, 06071 Badajoz, SPAIN.

Flecainide is a Class 1C antiarrhythmic drug. The metabolism of flecainide cosegregates with the polymorphic metabolism of sparteine/debrisoquine. Flecainide is administered as a racemate, and it is known that enantioselective drug disposition can differ in poor (PM) and extensive (EM) metabolisers. The pharmacokinetics of (+)-S- and (-)-R- fIecainide has therefore been studied in healthy volunteers to establish whether the disposition is stereoselective and to ascertain whether phenotype differences occur. Five PMs and 5 EMs phenotyped using sparteine were administered 50mg of racemic flecainide acetate orally under conditions of controlled urinary flow and pH. Plasma and urine samples were collected for 60 hours. The concentrations of (-)-R and (+)-S flecain[de in urine were determined by HPLC after derivatisation. Plasma R- and S-flecainide concentrations were measured by GCMS using a chiral capillary column, In EMs no differences in the plasma concentrations of R- and Sflecainide were observed. The urinary excretion of R- (6.8-+1.Omg) and S- (7.0-+ 1.0mg) flecainide was also comparable. Consequently no differences in the pharmacokinetics of the enantiomera were noted in EMs. In PMs urinary recovery of R-flecainide (13.6• was greater (p< o.o5) than that of the S enantiomer (10.5z3.2mg). In PMs plasma concentrations of the enantiomers were initially comparable, however with time the proportion of the R enantiomer in plasma increased. The half-life of R-flecainide (13.0h) was longer (p<0.05) than that of the S enantiomer (9.9h). The renal clearances of Rand S-flecainide were similar. Total clearance was greater for the S enantiomer and consequently the nonrenal clearance of S-flecainide was nearly double that of R-flecainide. During chronic flecainide therapy in PMs, higher concentrations of R- than S-flecainide can therefore be anticipated. Supported by the Robert Bosch Foundation, Stuttgart. Dr. Margarete Fischer-Bosch-lnstitut h3r Klinische Pharmakologie, Auerbachstr. 112, D-7000 Stuttgart 50 / FRG.

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POLIMORPHISM OF THE 4-HYDROXYLATION OF DEBRISOQUINE IN THE SAN BUSHMENOF SOUTHERNAFRICA De K. Sommers, J. Moncrieff and J. Avenant The metabolic o x i d a t i o n of debrisoquine has been studied in a group of 96 San Bushmen, a population which is presumably more g e n e t i c a l l y homogeneous than Caucasians. Debrisoquine (10 mg) was given to the f a s t i n g subjects and a l l urine was collected f o r 8 h postdose. The metab o l i c r a t i o (MR) f o r each subject was calculated from the quotient: % dose eliminated as debrisoquine/% dose eliminated as 4-hydroxy-debrisoquine in the c o l l e c t i o n period. The on-column d e t e c t a b i l i t i e s were 50 and 20 ug f o r debrisoquine and 4-hydroxy-debrisoquine respectivel y . When no metabolite was detected, the minimum detectable concentration f o r the method was used in cal cul at i n g the r a t i o s . Using an MR>I2.6 as the c r i t e r i o n f o r poor metabolism, the assay r e s u l t s showed 18 slow metabolizers in the 96 Bushmen subjects i . e . 18.75% which is very much greater than either the 10% found in Caucasians (A. K~pfer, Eur. J. Clin. Pharmacol. 26, 753, 1984) or the 0% in Japanese (J. Nakamura, CTTn. Pharmacol. Ther. 38, 402, 1985). The median result, 1.54, for fast metaboli~rs shows a shift to the right for the Bushman results as compared to published Caucasian results of 1.1. Furthermore, in the San Bushmen, the extensive and slow metabolic groups are not separated by a large antimodel gap and probit analysis of the data suggests that four groups may be present, i.e. at least three isozymes for the 4-hydroxylation in this population. The putative presence of these in the presumably genetically homogenouspopulation, raises the question as to what selective pressures may be responsible for bringing about such inter-ethnic differences in isolated groups. Department of Pharmacology, University of Pretoria, P. O. Box 2034, PRETORIA, 0001, South Africa.

I~-ACEgYIATION PHENOTYPING ~ITH SULPHADIMIDINE IN A TURKISH POI~JIATION A. Bozk-art, N.E. Bs@cl, S. IG%lan and S.O. Kayaalp The distribution of acetylator phenotypes ~,~s studied in 244 unrelated subjects. Sulphadimidine and its acetylated mstabolite were measured in 6 h plasma and 0-6 h urine samples after an oral dose (I0 mg/kg). Subjects with 4 3 7 . 5 % acetylated-sulphadimidine in plasma ~ s regarded as slow acetylators mld others as fast acetylators. The mean plasma concentration of acetylated-sulphsdimidine was about 2. 5 times lower in slow acetylators than in the rapid acetylators. Urinary excretion of total sulphadimidine (free + aoetylated) was also si~ificant!y (p~0.05) lo~er in slo~; aoetylators compared with fast aceiylators. The frequency of slow acetylators was 60. 7 % in the population. Sulphadimidine acetylation sho~.~ed no variation due to sex, age, weight and presence of disease. Department of Pharmacolo~, School of ~ledicine, Hace%tepe University, 06100, Ankara, Tumkey

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GENETIC ANALYSIS OF DEBRISOQUINE/DESIPRAMINE HYDROXYLATION POLYMORPHISM IN A SWEDISH POPULATION M.-L. Dahl-Puustinen~ I. Johansson, D. Lee t M. Ingelman-Sundberg and F. Sj6qvist The capacity to hydroxylate debrisoquine (D) is bimodally distributed in the population, 5-10% of Caucasians being slow hydroxylators. Pedigree studies suggest that the slow hydroxylator phenotype is inherited as a monogenic, autosomal recessive trait. Recently, a cDNA for human cytochrome P-450dbl, the deficient enzyme, has been cloned (Gonzalez et al 1988), and two polymorphic restriction fragments associated with the slow hydroxylator phenotype have been identified (Skoda et al 1988). Earlier studies from our laboratory indicate that 2-hydroxylation of desipramine (DMI) is under the same genetic control as hydroxylation of D. We are now determining the metabolic ratio of DMI in a Swedish population with known D hydroxylation phenotype, including a number of two-generation families (Steiner et al 1985). Genomic DNA from the same individuals is analysed by RFLP in order to find polymorphisms associated with the slow hydroxylator phenotype. In our material, polymorphisms in the P-450dbl-gene have been shown using the restriction endonucleases Xba I, Eco RI, Hind III and Bgl II, and three different RFLP-patterns have been identified among the slow hydroxylaters. Results on the analysis of the P-450dbl-gene with RFLP in the Swedish population will be presented and related to the hydroxylation phenotype assessed with both D and DMI. Dept of Clin Pharmacol, Karolinska Institute, Huddinge Univ Hosp, S-141 86 Huddinge, & Dept of Physiol Chem, Karolinska Institute, S-I04 Ol Stockholm, Sweden

DEBRISOQUINE HYDROXYLATION POLYMORPHISM AND PERSONALITY C. Alm, L. Bertilsson, C. de las Carreras, G. Edman, D. Schalling and J. Wid@n The debrisoquine hydroxylation polymorphis~ has clinical significance as the enzyme involved also metabolizes several important drugs, e.g. tricyclic antidepressants. The distribution of the urinary metabolic ratio of debrisoquine/4-hydroxydebrisoquine has been found to be bimodal with appr. 5-10% of Caucasian populations, being poor hydroxylators of debrisoquine. Since the start of debrisoquine phenotyping of healthy Swedish subjects in 1979 (n=769), we have examined a large ntmlber of poor hydroxylators and have got the impression that they differ in personality from the extensive hydroxylators. The idea occurred that the debrisoquine hydroxylase may also metabolise endogenous substances related to personality. Method: All poor hydroxylators (n=5l) and 102 age- and sex-matched controls among the 718 extensive hydroxylators got a personality questionnaire, the Karolinska Scales of Personality (KSP) inventory. As many as 88% of the poor and 81% of the extensive hydroxylators filled in the questionnaire. Results : Mean KSP scale scores in beth groups were close to the average in a standardization sample. Poor hydroxylators had significantly lower scores in the KSP Psychasthenia scale (F(I,124)=4.52; p<0.05) and had a higher frequency of extreme response alternatives (F (i,124)=7.58; p<0.01) as compared to extensive hydroxylators. This shows that the poor hydroxylator personality is characterized by high vitality , alertness, efficiency and ease of decision-making. We suggest that the debrisoquine hydroxylase is involved in the formation or catabolism of an endogenous substance of importance for CNS-function. Dept of Clin Pharmacol, Karolinska Institute, Huddinge Hospital, S-141 86 Huddinge, SW~DI~ and Dept of Psychiatry and Psychology, Karolinska Institute, Karolinska Hospital, Box 60500, S-I04 01 Stockholm, SW~DE~.

A 202

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PP 06.55

POLYME~RPHICF{]6~I~TIIBNOF MIRPHI~FR~ CODEI~ IN POORAN) EXTENSIVE ~TY~BOLI~RS [}- DEXTRCMZTFK]RPF~:RELATIONTO T~ PRESENCEOF AN I ~ IDENTIFIED CYT~CMs P~50 Mortimer (J, PerssomK, L a ~ M G, Spalding D, MeyerU, Race A The effect of many drugs depends to a large extent on the activities of drug metabolizing e~ymas in the liver. Genetic variation is probably the most iMoortant cause of the large differences in drug metabolism between individuals. The mast wallknswe polymarphlsm of the enzymatic drug oxidations is the debrisogajne ([]3) type, dol, ~hich constitutes 5-I~6 of the caucasian population, having an impaired espacity to metabolize DB, dextromethorphan (ON) and many other drugs. This study describes the formation of morphine (M) and noreodeine (NO) from the analgesic drug c~deine (C) in human liver mierosomas of poor (PM) end extensive (EM) metabolizers of DM (in rive and in vitro). Methods: Liver mierosomns were isolated from wedge biopsies obtained at laparat~my of 12 patients. The oxidation of C or DM was studied and plasmO and incubation s~les ,~ere analysed with Bn H~ The content of eytanhrcm P-45D ~l was gaantitated in Western blots using a specific antibody (MAb 114/2) against the P-450 cbl isoenzyme. Results: The O-demethylatian of C was highly correlated with the O-demethylation of DM (formatien of dextrorphan (D)) (0.90). The formatian of NC yeas cata]ysed at a (>-Fold higher rate than the formation of M. The ratio:funned NC/fsrmad M, was sppr. 50 in the PM (n:2) and 2.6-11 in the ~4 (n=10). The corresponding ratio of N-/O-dem. metsbolites of DM in the PM was sppr~ I0 and in the EM 1.2-4.6. No protein band was found with Western blots in liver mierosomes of the ?M but in add micros~s of the [}4. The band intensity correlated with the rate of M-Formation (0.95) and the rate sf D-fo~matien (0.88) in the EM. Co~rlusiona: The Formation of M from C correlates with the formatian of D from []M and is probably concordant with the eytschrome P-450 enzyme of the debriscgaine-type. The co-measurement of NC and M formation from C may provide a tool to phematype individwals in vitro with respect to the F~lymorphism of the cytschrome P-450 type dog. seems preferable for the phenotyping of the some polymerphism in vivo.

POPULATION STUDY ON ACTIVITIES OF CYTOSOLIC AND MICROSOMAL EPOXIDE HYDROLASES IN HUMAN LYMPHOCYTES M.J. Moor and R.H. Levy Many cytotoxic and genotoxic arene oxide metabolites of drugs and chemicals can be inactivated by the epoxide hydrolase (EH) enzyme system. Since EH activity seems to be a determining factor for individual susceptibility to arene oxide mediated toxicity, knowledge of an individual's capacity to eliminate epoxides would allow rational risk assessment. In the present study, microsomal (EHm) and cytosolic E H (EHc) were investigated in subcellular fractions of lymphocytes from 108 adult individuals. Cis and trans-stilbene oxide were used as substrates. Activities of EHm and EHc were repeatedly determined (n=5) in 6 individuals and were found to be stable over a 2 month period. Mean coefficients of variation were 14.5% and 15.0%, respectively. Within the investigated population EHm activities were between 28.3 and 78.4 pmol/min/mg (mean + SD: 50.5 + 11.6 pmol/min/mg). These finding indicate that a possible polymorphism of EHm activity has to occur in much lower frequencies than other well known polymorphisms in oxidative drug metabolism. The observed variation in EHc activities was much larger and values were determined between 2.86 and 31.6 pmol/min/mg (mean + SD: 19.1 + 5.6 pmol/min/mg). Additionally, one subject was found to be deficient in EPIc activity. The toxicological significance of this finding is not yet understood. Department of Pharmaceutics, University of Washington, 303 Bagley Hall, BG-20, Seattle, W A 98195.

Div. of Clinical Pharmacology, University Hospital, S-751 85 Uppsala, Swaden

PP 06.56

PP 06.54 SEX

DIFFERENCES

IN A M I N O P Y R I N E

ACTIVITY IN D.A. RAT I / V E R

N-DEMETHYLASE

MICROSOMES.

I. Benltez y LA. Garda-Ag~ndez.

Department of Pharmaco]ogy, Medical School, University of Extremadura, Badajoz, Spain. Previous studies have shown that debrisoquin hydroxylation presents sex differences in D.A. rats. males being extensive metabolizers while females are poor metabolizers. The present study was undertaken to investigate if the N-demethylation of aminopyrine is also sex related in D.A. rats. Therefore, we have assayed aminopyrine N-demethylase activity in liver microsomes from 12 DJ~. rats (6 males and 6 females]. Our results show that aminopyrlne N-demethylation in D.A. rata is higher in males (99 + 5 mU/mg) than in females (67 i 6 mU/mg) and this difference was statistically significant (P = 0.002). On the other hand, P450 levels were not significantly different (P = 0.277) between males (1.3 + 0.2 nmal/mg) and females (0.95 + 0.2 nmol/mg) in these rats. Our results suggest that aminopyrine N-demethylase activity is somewhat related to sex in D.A. rats. Whether this difference is related to sexual hormones (as it has been shown for debrlsoquin hydroxylation in these rats) or to any other mechanism, deserves further study. Supported in part by CAICYTgrant PB 85-0154. J. Benitez, Facultad de Medicina. Av. de Elvas s/n. E-06071 Badajoz. Spain

IMMUNOLOGIC CHARACTERIZATION OP CYTQCHROME P450 lID SUBFAMILY IN NON HUMAN PRIMATES. Edacqz-Ai~rmin~ K.Gue~uen"r I,Rnhieux und LAlvarmz'. The most widely investigatedpolynorpbiam of oxidative drug metabolism is related to debrisoquime hydroxyiation. 3 to 9% of the caucasian population, because of a specific debrisoquina cytuchrone P45D (P45D dbl) defect, are poor metabnlizers. It is admitted that an animal model for pharmanogenetic studies would provide distinct advantages over studies in man. We recently reported the in vitro polymorphic metabolism of dehrisoquine in non human primates. We conducted in vitro immunologic studies using anti liver kidney microcome antibody (LKMI) found i~ autoinune hepatitis which specifically recognize P450 dbl [dB kDA] in human liver, to characterizethis model. MATERIELS AND METHODS, . Sere containing various antibodies were obtained from 8 patients at the onset of autoimmune hepatitis. In innuncblot analysis of rat aicrosomes, sere were identified as having LKNA (anti 50kDA, n:3 associated with anti 66kDA in 2 cases, anti 66hDA alone n=3), SMA {n=l) or anticytonol antibody (n=1). . Microsomea were prepared from livers of two extensive met~olizers primates. Metabolic studies used dextrnnmthnrphan(DEM} as a substrata of P450 dbl. The formation nf dextrorphan I~SR} its hydrnxylmtmd metabolitm wa~ memsnrud by KPIC following a simple extraction procedure. R~@ULT@ lunnoblot analysis. Serum (SI) from a patient with a high titer of anti LKMA (anti 50hDA) was used. Two proteins of OhDA and (TXDA respectively were recognized by this specific antibody in primate liver minrosomes. It elan showed a reactivity with a protein of IBhDA (P450 dbl) in human liver nicrononua and 50kDA (P450 dbl and @2) in rat liver microsomes. Innunoinhibition studies, The inhibitory effects of various hera nn DEM metabolism were studied, With Sl, a strong effect was observed at titers of 1:1000 or higher. The maximum inhibitory potency uncured at DEM concentration of 50pM. Sera containing anti (gkDA and anti 47hDA antibodies were tested at titers of hl0g and 1:500. The relative DOM formation was less than 50% at 1:100 and less than 75% a~ 1:500, when compared to control serum. In contrast, sara containing other types of antibodlen had no inhibitory effect on DEM metabolism. COMCLUSION The anti LKMI antibody used specificallyrecognizes two microaomel proteins (UkDA and ~9kDA) of the P45011D snbfamily in primate livers. This antibody exhibits e )troug inhibitoryeffect on DEK metabolism in vitro, The )ri~mte is u useful model for studien on PISDIID subfamily polymorphisn, M~pital MOBERT DEBMK, " INBERM U56 - Paris FRANCZ.

A 203

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PROPAFENONE: CONCENTRATION-RESPONSE EFFECTS ON ECG AND VENTRICULAR ECTOPY E.B. Kirsten, A. F i s h e r , R.G. Zoble, J. Brewinqton and the Propafenone Research Group.

INFLUENCE OF BARUCAINIDE ON RENAL FUNCTION AND HEMODYNAMIC PARAMETERS IN PATIENTS WITH KIDNEY DISEASE A. N o k h o d i a n , M. L i n d e , A. H a l a b i and W. K i r c h Barucainide, a pyridine derivative, i s a new I B antiarrh~thmic a g e n t which i s m a i n l y m e t a b o l i z e d by the l i v e r . The p h a r m a c o k i n e t i c s and the i n f l u e n c e o f b a r u c a i n i d e on r e n a l f u n c t i o n as w e l l as on e l e c t r o c a r d i o g r a p h i c p a r a m e t e r s were s t u d i e d in 12 p a t i e n t s w i t h normal and w i t h impaired renal function. 200 mg b a r u c a i n i d e were a d m i n i s t e r e d as a s i n g l e o r a l dose t o t h e s e subj e c t s . Peak plasma l e v e l s , t h e area under the plasma l e v e l t i m e - c u r v e and the t o t a l body clearance of barucainide did not differ signific a n t l y between p a t i e n t s w i t h normal and w i t h impaired renal function. The t o t a l body c l e a r a n c e o f b a r u c a i n i d e was 26.1 + 13.3 I / h in p a t i e n t s w i t h i m p a i r e d r e n a l f u n c t i o n and 31.0 + 21.8 I / h {X ~ SD) in p a t i e n t s w i t h normal r e n a l - f u n c t i o n . Thus, f o l l o w i n g a s i n g l e o r a l dose o f b a r u c a i hide t h e r e were no a l t e r a t i o n s o f plasma l e v e l s in p a t i e n t s w i t h r e n a l i n s u f f i c i e n c y as compared w i t h t h o s e w i t h normal r e n a l f u n c t i o n . In a d d i t i o n , b a r u c a i n i d e d id n o t have any s i g n i f i c a n t e f f e c t s on k i d n e y f u n c t i o n o r on e l e c t r o c a r d i o graphic parameters. I. Medizinische Klinik, Christian-AlbrechtsUniversit~t, S c h i t t e n h e l m s t r a s s e 12, D-2300 K i e l

Propafenone (PPF) is a Class IC sodium channel blocker with beta blocking activity. We examined its antiarrhythmic and ECG effects in a placebo-controlled double-blind study of 169 patients with frequent ventricular ectopic activity (YEA). Patients were randomized to 1 of 5 parallel groups: placebo or PPF (112.5, 150, 225 or 300mg) every 8 hours. Ambulatory monitoring and 12-1ead ECGs were obtained at baseline (placebo) and after two weeks of therapy. These data were grouped by six ranges of trough PPF concentration. ECG data were expressed as % of baseline while YEA data were expressed as % of patient s with ~90% VEA suppression.

PVCs Pairs Runs PR QRS HR *p<0.5

Propafenone <.i .1<.25 18 30 38 74 50 83 1.3 12.6,* 0.9 6.8** 2.6 -2.4 **p<0.01

Concentration (ug/mL) .25<.5 .5<1.0 1.0<1.5 >1.5 47 55 60 67 70 88 71 83 78 94 i00 i00 13.3"* 13.0"* 25.6** 29.9** 8.7** 7.5** 12.5,* 16.0,* -i.i -4.8 -8.7* -8.8*

PPF suppression of YEA was concentrationdependent with pairs and runs suppressed at lower PPF concentrations than PVCs. PPF increased PR & QRS duration. QTc was unchanged. Minimal (9%) h e a r t rate slowing was seen at 1 ug/mL; presumably due to 9-blocking activity. Knoll Pharmaceuticals, University of South

Whippany, NJ Florida, Tampa,

07981 FL

and

PP 06.58

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FIRST pHASE OF A CLINICAL ASSAY WITH A SUPPOSED NEW ANTIARRHYTHMIC IC: CRE-1087. J.R. Suarez, J.R. Azanza, M. Catalan and J. Sonorato We report the results obtained after the administration to 8 healthy volunteers men between the ages Of 19-24, and 75 Kg., of a single dose of placebo 150, 300, 450, 600, 750 y 900 mg. They were given every 15 days orally for determining the active dosis without t o x i c effects. The volunteers had passed a physical exam and exhaustive c o m plementary explorations and avoided fatigue, lack of sleep, alcohol, nutrition alterations since at least a week before the study. The evaluation was based on clinical parameters (temperature, respiratory and heart rate, systolic and diastolic blood pressure, neurologic exploration and anamnesls) ECG (PR, QRS, QT and QTC) and isotopic technics (Muga tecnic - TC 99m~ to determinate the ejection f~action) as Well as Other complementary analyses (blood cell count, serum biochemistry and urine analysis).

THE PLACE OF DIGOXIN IN THE T R E A T M E N T OF VENTRICULAR FAILURE DUE TO C0R PULMONALE

Farmacocinetir

TmaX = 3-4 h, T{i/2)(Beta), 23 h. (AUCI: Individual varlability. Dosls-dependent kinetics

(900 mq)

Pharmacodynamics DOSIS 0 150 300 450 600 750

900

EFFECT ON Physical rameters

pa

no

no

no

no

no

no

(EP,HR ...| ~

no

no

no

no

no

no

~22.6ms~

no

no

no

no

no

no

(14.6~) no

TOLERANCE An hour after the dosage of 600 mg, in one of the patients appeared a feeling of light intoxication (inebriety) and mental slowness of an'hour's duration. A dosage of 750 mg was given to one patient with good tolerance. The two patients to whom a 900 mg dose was given showed sickness, weakness, blurred vision and a metallic taste in the mouth 45-60 minutes after taking the 900 mg dose. The maximum intensity of the adverse reaction occurred 3-4 hours later when they had scalp paresthesla, mental toxicity feeling, concentration disturbance, decrease of alertness and mental activity, cephalalgia, weakness and tiredness a s w e l l a s sleepiness or hypersomnia that was prolonged for 8 hours. CONCLUSION ~RE-1087 at the indicated dosls produce sigmlflcant electrocardiographic effects (increase in PR and ORS) and inotroplcs (decrease in EF), whose appearance and duration correlated well with the plasmatic levels, which occur a s well wlth the appearance of the adverse r e a c t i o n s Clinical Pharmacology Service, Universltary Clinic of Navarra, University of Navarra, Plo XII s/n, 31080 Pamplona, Spain.

S. Poll6,

Z. Rumboldt,

Z. Duji6,

RIGHT

J. Bagatin

The value of digoxin in the treatment of decompensated chronic cot pulmonale was ~nvestigated in a randomized double-blind, cross-over, placebo-controlled trial. Successive 34 patients with evident right heart failure were included in the study. The severity of heart failure was assessed according to a clinicoradiographie scoring system (Heart Failure Score). The heart failure worsened during the placebo-period in 8 (4 with atrial fibrillation, 2 with S gallop, one with cardiothoracie ratio > 0.50 and on~ with sinus rhythm) or 23.59 of t h e p a t i e n t s . By regression analysis the heart failure signifieantly deteriorated only in the subgroup of patients with atrial fibrillation. The mean maintenance daily dose of digoxin was 0.30+ 0.03 m~ with the mean serum level of 1.7+0.7 nmol/LU Digoxin was successfully discontinued (without worsening of the heart failure) in 26 patients (76.59), and no significant improvement on digoxin was observed in the subgroup of patients with S~ g a l l o p . It is concluded that digoxin has no beMeficial effect on heart failure in patients with chronic cot pulmonale except in those with atrial fibrillation. The side-effects may seldom be avoided, however.

Clinical Hospital "Firule" 58000 Split, Yugoslavia

A 204

PP 06.61

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PHYSICO-CHEMICAL ASPECTS OF COMPLEX FORMATION FOR GLYCOSIDE AND NONGLYCOSIDE CARDIOTONICS E. V ~ . R o s c h u p k i n a l A.I. G r i n e v i c h ? V. U. D y a c h e n c o , T. G. S s m a r s k a y a I a p r e s e n t w o r k w e h a v e s t u d i e d the p r o c e s s of c o m p l e x f o r m a t i o n for g l y c o s i d e and n o n g l y c o s i d e c a r d i o t o n i c s b y t h e m e t h o d of e l e c t r o n U V spectrophotometry. The q u a n t i t a t i v e e s t i m a t i o n of c o m p l e x f o r m a t i o n w a s p e r f o r m e d b y t h e a i d of s p e c t r o p h o t o m e t r i c t i t r a t i o n . The t ~ p i c a l s t r i a l s of d r a g a b s o r b t i o n w e r e c h o s e n as a control. It h a s b e e n s h o w n t h a t t h e m o s t s t a b l e c o m p l e x e s are f o r m e d as a r e s u l t of i n t e r a c t i o n b e t w e e n d i E o x i n ( X ) a n d d o b u t a m i n e (II), and t h e w e a k e s t o n e s - b e t w e e n s t r o p h a n t i n (III) sand II (they differ aproximately in 7 times in stability). C o m p a r i n g t h e s t a b i l i t y c o n s t a n s f o r t h e same d r u g w i t h the s e l e c t e d g l y c o s i d e one c a n r e v e a l t h a t d o p h s m i n e (IY) c o m p l e x e s are of approximately equalstrength, theophylline (Y) f o r m s m o r e s t a b l e c o m p l e x e s w i t h III, and II w i t h I. The d e t e c t e d e f f e c t c a n be e x p l a i n e d b y d i f f e r e n t d o n o r - a c c e p t o r p r o p e r t e s of g e t e r o e toms i n n o n g l y c o s i d e c a r d i o t o n i c s t r u c t u r e and also b y d i f f e r e n t p o l a r i t y of I and III. T r i p l e c o m p l e x e s o~ d r u g s i n q u e s t i o n w i t h g l y c o s i d e s , C a L § and M g ~ + ions are m o r e s t a b l e i n c o m p a r i s ~ with double complexes,excluding II+I+Ca2+ and Y + I I I + C a ~ + i n t e r a c t i o n s . I n t h i s case t h e a d d i t i o n of Ca 2+ ions to the s y s t e m of g l y c o s i d e and n o n g l y c o s i d e c a r d i o t o n i c s l e a d s to. The d e c r e a s e i n s t a b i l i t y c o n s t a n t of c o m p l e x e s to b e f o r m e d . The e s t a b l i s h e d p h e n o m e n o n p r o v i d e s f o r such p r o c e s s e s to e x i s t i n t h e l i v i n g o r g & u i s m , t h a t s t i p u l a t e s i n s p e c i a l i t i e s of p h a r m a c o d i n a m i c s f o r c o m p l e x a p p l i c a t i o n of g l y c o s i d e and nonglycoside cardiotonics. Kiev Medical Institute, Dept.of Pharmacol.& Cli~ Pharmacol.,Bulv.T.Schechenko~13,Kiev, USSR

S ~ U M CONCI~WfRATICNS OF DIGITOX~ (DGTX) AS RELATF/D TO CARDIAC TOXICITY IN A CASE OF S ~ ~ E TREATED WITH FAB FRA~4~!~ OF DIGITALIS ANTIBODIES (FAB) V. Kurowski~ H. Iven r H. E0onlagic* and G. Taubert* The injectlon of FAB hasbeen shown to be an effectivi method of treating digitalis toxicity. The FAB dose to be applied is usually based on an estimate of ingested drug (80 mg FAB for I mg digoxin or DGTX) and is generally infused over a short period of time. In the case reported here massive DGTX intoxication was treated by prolonged i.v.-infusion of FAB. Blood and urine samples were taken at 3 h intervals for monitoring the efficacy and adequacy of FAB treatment. In an attempted suicide a 36 year old man ingested 35 mg DGTX. Arriving at the ICU he developed ventricular fibrillation which was repeatedly treated by cardiac defibrillation. Conccmittantly 320 mg FAB ~ s infused within 4 h. Total ~ concentrations ~ r e determined in s e ~ n end urine directly and after 16 h dialysis of a I ml sample against I 1 phosphate buffered saline by fluorescence polarization immunoassay (after protein precipitation to release albumin and FAB-boundDGTX). The difference in concentration (hetween unprocessed end dial~sed sanples) was an index of DGTX bound to FAB. Initlal sel~m DGTX concentration ~as 535 nmol/l. Cardiac toxicity ceased when most of the DGTX in serum was FABbound, however, reappeared with increasing amounts of non-antibody-bound DGTX. This necessitated 3 additonal FAB infusions within the next 48 h (400 mg, 80 mg, 80 mg). During the infusion of FAB serum DGTX concentrations always rose, (peak level: 635 nmol/l, > 90 % FABinactivated) indicating redistribution of DGTX from tissue to se~-um~. 5~ximum renal clearance of FAB-bound DGX~ was 36 ml/min. No ensaturatedantibody and only little free DGTX was found in the urine. In addition to FAB therapy cholestyramine (3 x 8 g/d, throughout) was given orally. 98 h after onset of therapy DGTX se~-~m level was back within the therapeutic range. In conclusion cardiac toxicity of DG~fX can be easily reversed with FAB antidot. In cases of massive DGTX overdose FAB - after a loading dose - should be infused at an appropriate rate for several hours to guarantee sufficient inactivation of redistributing drug, Inst. filr phamL~ukologieund Klinik fiir Innere Medizin*, Medizinische Universit[t zu ~dbeck, D-2400 ~dbeck, FRG

PP 06.62

PP 06.64

PREDICTION OF DIGITOXIN DOSE AND PI~XSMA CONCI~NTRATIONS DURING MAINTIg~ANCE TRF~ATMENT B.G. Woodcock, T. Gundlach, J. Lurg, K. Tews~ K. Abt. From studies on 15 selected patients Bussey et al. (Pharmacotherapy, 8, 235, 1988) reco~nended a digitoxin maintenance dose of 0.00143mg/kg lean body weight based on a target concentration of 22 ng/ml. Concentrations above 25 ng/ml occurred in 3 patients and above 30 ng/ml in I patient. We have carried out multiple linear regression analysis on 247 hosptalised patients, mostly with cardiac insufficiency of which 53 had plasma concentrations above 25 ng/ml. All subjects were in steady-state, none had liver disease, and drug interactions as a source of variation in Cp could he excluded. The equation Cp = -1.85 + 16(DOSEug/BWkg), which accounted for 69.4% of the variance, predicts that a maintenance digitoxin dose of 0.0012mg/kg body weight should produce a digitoxin plasma level of 1 7 . 5 ng/ml (approximately the mid-point of the range 10-25 ng/ml). Differences in age, creatihine clearance and sex made no significant improvement in this prediction accounting for a further increase of less than 3.6% in the coefficient of determination when taken together. The correlation between Cp-observed and Cp-predicted using the above equation, was examined prospectively 9 in a further 68 patients. Confidence intervals for 8 (Binomial distribution), showed that a maximum of 23% of patients would have concentrations outside the range 10-25 ng/ml and a maximum of only 14% outside the range 10-30 ng/ml (P = 0.1). These results emphasise the importance of h0dy-weight for the determination of digitoxin maintenance doses and confirm that Cp can be predicted within clinically useful limits. Abteilung f. Klinische Pharmakologie, Universitatsklinik, Theodor-Stern Kai 7, D-6000 Frankfurt/Main.

DOSE-RESPONSE H. F. Marlow

RELATIONSHIPS

OF XAMOTEROL

Xamoterol ('Xamtol', 'Cerwin') is a partial agonist acting on the ~l-adrenoceptor effective in the treatment of heart failure. Invasive haemodynamic studies have shown that xamoterol has a mild positive inotropie effect. The relationship between oral doses of xamoterol (20, 50, i00 and 250 mg) and the positive inotropic response measured by systolic time intervals, QS21 , showed that the top of the dose-response curve was reached with a dose of 100mg. The present study was conducted in 8 subjects at rest to study the doseresponse relationships over a 24 hour (h) period comparing the effects of oral doses of xamoterol (I00, 200 and 400mg) and placebo on QS21 using a double-blind, randomised, cross-over design. Decreases in QS21 (milliseconds) compared with placebo were: Dose 100mg 200mg 400mg

lh

2h

31"**

28***

33*** 35***

28*** 29***

6h

14h

24h

5

0

9*

15"* 17'**

8* I0"*

3 7*

*p
A 205

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CLINICAL STUDIES OF XAMOTEROL TREATMENT FOR CONGESTIVE HEART FAILURE WITH CHRONIC ATRIAL FIBRILLATION (AF) M. Takeshi, T. Sato, O. Tamura, H. Tazawa and H. Miyashita The clinical efficacy of xamoterol, a new beta~ partial agonist, was investigated in 13 patients with mild to moderate cardiac failure accompanying chronic AF during maintenance therapy with digitalis. Xamoterol maintenance i00 mg twice daily was administered for 6 months, and we compared the NYHA functional classification, cardiothoracic ratio (CTR), left ventricular function estimated by means of echoeardiography and gated equilibrium radionuclide angiog~aphy, blood chemistry, plasma catecholamine, serum digoxin concentration (SDC) before the treatment started with the same parameters at i, 3 and 6 months after the start. Also the effect of xamoterol on the ventricular response of AF was studied during 24-hour ambulatory electrocardiography and during treadmill exercise. The plasma xamoterol concentration was measured by RIA. Three months after the xamoterol treatment began, the NYHA functional classification had improved (p < 0.0i), and the CTR had decreased from 57.2% to 56.1% (p < 0.05). After 6 months the ejection fraction, determined by gated equilibrium radionuc]ide angiography, increased from 35.4% to 40.2% (p < 0.05). During the period between 7 P.M. and 8 A.M., the hourly ventricular rate significantly increased. Xamoterol reduced the ventrioular rate during exercise periods. After the treatment, the SDC decreased. Xamoterol appears to be a promising drug for mild to moderate cardiac failure, and is effective in stabilising ventricular rate during AF both at rest and during exercise. The Second Department of Medicine, Teikyo University School of Medicine, 2-11-i Kaga, Itabashi-ku, Tokyo, 173,

EFFECT OF R G W - 2 9 3 8 (AN I N O T R O P I C V A S O D I L A T O R ON S Y S T O L I C T I M E I N T E R V A L S IN H E A L T H Y V A L U N T E E R S . D.J. W e i d l e r , Q . A . M e k k i , L. P a v e s , N. B a l t o d a n o R. R i l e y a n d D . C . G a r ~ . R-GW-2938 was found to be a novel inotropic vasodilator agent in animal studies. Its tolerability and effects on systolic time intervals (STI) were studied in 16 healthy volunteers. STI were derived from simultaneous recording of ECG, p h o n o c a r d i o g r a m and indirect carotid pulse. Subjects were randomized in a double-blind f a s h i o n to r e c e i v e , in t h e f a s t i n g s t a t e , in 3 sessions, 3 o r a l d o s e s of p l a c e b o (4 subjects) or 3 i n c r e a s i n g doses of RGW-2938, e i t h e r I, 4 and 8 mg (6 s u b j e c t s ) or 2 , 6 a n d l0 mg R G W - 2 9 3 8 (6 s u b j e c t s ) . H e a r t r a t e (HR), STI, pre-ejection period (PEP), left ventricular ejection time index (LVET-I), total electromechanical systole index (QS2-I) and the ratio Q S 2 / L V E T w e r e m e a s u r e d b e f o r e , a n d at 2#4, a n d 6 h o u r s a f t e r e a c h d o s e . No c h a n g e s w e r e o b s e r v e d w i t h d o s e s of 1 and 2 mg.

Japan

Maximum DOSE Placebo 4 mg 6 mg lOmg

Mean Changes HR PEP + 2 + 7 +18 +19

-ii -15 -13 -17

(4 h o u r s ) LVET-I -Ii -19 -37 -37

from Baseline. QS2-1 QS2/LVET -21 -33 -48 -52

-0.02 -0.01 +0.03 +0.03

STI a r e m e a s u r e d in m i l l i s e c o n d s . HR was increased, while LVET-I and QS2-1 decreased (p
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A PHASE I STUDY OF MS-857, A NEW POSITIVE INOTROPIC AGENT M. Ohta, H. Sasaki, M. Ohsaka, Y. Sasaki, N. Kawaguchi, K. Munakata, S. Etoh, Y. Okazaki, H. Hayakawa An isoquinolinone d e r i v a t i v e MS-857 is a new i n o t r o p i c agent and has been c l a s s i f i e d , on the basis of i n i t i a l in v i t r o and in vive experimental studies, as a phosphodiesterase (PDE) i n h i b i t o r with marked p o s i t i v e i n e t r e p i c and v a s o d i l a t i n g actions. A phase I study of t h i s agent, in which t o t a l of 19 healthy male volunteers aged 32.7• 7.9 years were subjected, was performed to define i t s pharmacological c h a r a c t e r i s t i c s and safety. Following a single oral administration of I, 2, 5, I0, and 15mg of MS-857 (n=5 f o r each), Tmax and Tel/2 were approximate]y 1.5 and 8 hours, r e s p e c t i v e l y , and both Cmax and AUC0_24increased dose-dependently. Heart rate increased s i g n i f i c a n t l y , whereas blood pressure remained unchanged. Following repeated oral administration of 5 and lOmg t . i . d , f o r 3 days (n=5 and 4, r e s p e c t i v e l y ) and of lOmg t . i . d , f o r 7 days (n=4), the AUC0_8 on the f i r s t day coincided well with that on the l a s t day of the study, i n d i c a t i n g no accumulation of the drug. Under echocardiographic observation, a p o s i t i v e i n o t r o p i c e f f e c t of the drug, with the dose of 2mg or more f o r the single administration and with e i t h e r dose f o r the repeated administration, was confirmed by the s i g n i f icant changes of a l l parameters except f o r endodiastolic dimension and volume. No serious adverse e f f e c t s were noted. In conclusion, MS-857 is a potent i n o t r o p i c agent and may be used safe and b e n e f i c i a l l y in the treatment of congestive heart f a i l u r e . Department of Medicine, Nippon Medical School, I - I - 5 Sendagi, Bunkyo-ku, Tokyo 113, Japan

CLINICAL EVALUATION OF AMEZINIUM METILSULFATE IN TREATMENT OF HYPOTENSION S. TSUTSUI, K. Tsuboi, K. Nagasawa and R. Honda Department of Psychosomatic Medicine, Toho University Tokyo Japan The clinical usefulness of amezinium metilsulfate (AMZ; |0 mg x 2 doses/day) in the treatment of hypotension was investigated by means of a multi-center double-bllnd comparative study using etilefrin hydrochloride (EF; 5 mg x 3 doses/day) as the control drug. The subjects of this study were 237 patients. In the evaluation of the final overall improvement, a rating of "improved" or better was given to 59.4% of the AMZ group cases and 53.4% of the EF group cases, and this difference was not statistically significant. However, when only the cases of essential hypotension were analyzed, it was found that the improvement wa s significantly superior in the AMZ group compared with the EF group. In both the AMZ and EF d~ug treatment groups, the supine systolic blood pressure was found to be significantly increased at the time of completion of the therapy compared with the time of starting the therapy. The diastolic blood pressure, on the other hand, was significantly increased only in the AMZ group. The heart rate was also found to be significantly elevated in the AMZ group at the time of completion of the therapy. Side effects were recorded for 5 AMZ group cases (4.6%) and 3 EF group cases (2.8%), but none of those symptoms were serious. In the evaluation of the usefulness there was no significant difference between the AMZ and EF groups, although the rate of "useful" or better was slightly higher in the AMZ group: 58.3% compared to 52.4% in the EF group. In other words, it was found that, in terms of the usefulness of the therapy, the administration of 2 daily doses of AMZ was sufficiently comparable to EF administered in 3 daily doses.

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ANTIBRADYCARDIC EFFECTAND KINETICS OF THE SPECIFIC MUSCARINIC ANTAGONISTAF-DX 116 BS IN HEALTHYVOLUNTEERS C. A. P. F. Su, P. Tanswell, U. Busch~ G. Heinzel, G. Nehmiz Conventional treatment of bradycardic arrhythmias comprises pacemaker insertion or therapy with anticholinergic drugs such as atropine. The chronic use of the latter is however limited by their side effects. A potent i a l new entity for this indication is AF-DX 116 BS (Thomae), a novel M2=cholinoceptor antagonist which has demonstrated high cardioselectivity in receptor binding and functional studies. We performed a double blind, randomized Phase I study in 4 groups of 12 healthy male volunteers receiving oral doses of placebo (P), 120 mg (DI), 240 mg (D2) or 480 mg (D3) AFDX116 BS respectively. Baseline heart rate (HR; i/min) were (mean • SD): 64 + 7 (P), 61 + 8 (DI), 64 t 6 (D2) and 64 + 7 (D3) (n.s.~ Maximal changes in HR were - 3 + 5 (P), 4 • 5 (DI; p < 0.1 vs P), 15 + 7 (D2; p < 07001), and 21 • 9 (D3; p < 0.001). Median duration of action was 3.2 h (DI), 14.0 h (D2) and 22.7 h (D3). No significant changes were observed in salivary flow, pupil diameter and near-point vision. Peak plasma concentrations of AFLDX 116 BS (analyzed by HPLC) were 84 (DI), 370 (D2) and 920 (D3) ng/ml; AUC values were 750 (DI), 2710 (D2) and 7560 (D3) ng.h/ml. Time to peak was 2.3 - 2.6 h; duration of effective plasma levels was prolonged as indicated by the mean residence time of 12.5 - 15.3 h. In conclusion, efficacy, specificity, and pharmacokinetics of AF-DX 116 BS after single oral doses in humans are highly promising and j u s t i f y further t r i a l s with chronic administration. Dr. Karl Thomae GmbH, Departments of Medicine and Biochemistry, D-7950 Biberach/RiB, FRG

SUPERFICIAL VEIN RESPONSIVENESS TO NORADRENALINE IN MONOZYGOTIC AND DIZYGOTIC TWINS S.G. Carruthers, A. Luthra and K.R. Borkowski Noradrenaline (NA) induced constriction of dorsal hand vein (HV) diameter, measured by linear variable differential transformer, shows wide intersubject variability. Genetic factors influencing the dose-response and concentrationresponse relationships of HV contractility to NA and the disposition of NA within the vein have been investigated in a study of twins. Doses of NA required to constrict HV by 50 percent (ED50) and the corresponding NA concentrations (EC50) were determined at steady state over an incremental range of NA infusion rates. The subjects were 6 pairs of monozygotic (MZ) twins, 6M, 6F, aged 17 to 42 years, and 6 pairs o f dizygotic (DZ) twins 8M, 4F, aged 20 to 28 years. ED50 ranged from 0.7 to 39 for MZ and 1.2 to 48 ng/0.1 ml/min for DZ twins. EC50 ranged from 2.1 to 46 for MZ and 0.9 to 32 ng/ml for DZ twins. Relationships between dose and concentration of NA for individuals exhibited positive linear relationships. Slopes of regression lines reflect disposition of NA which ranged from 0.87 to 1.62 ml/min for MZ and 0.74 to 2.5 m]/min for DZ twins. MZ twins showed a high level of concordance for ED50, EC50 and disposition of NA, whereas variability between DZ twins was similar to that between unrelated subjects. Since variability in NA disposition accounted for only a 3-fold range between subjects, we conclude that genetic aspects of alpha-adrenoceptor function and/or vascular contractility must account for the wide variability in HV responsiveness to NA. Robarts Research Institute, University Hospital, University of Western Ontario, London ON, N6A 5A5; Victoria General Hospital, Dalhousie University, Halifax NS B3H 2Y9, Canada

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RE-PERFUS'IONPOST ISCBEMIA AND OPIOIDS; EFFECT OFOPIOID ON SUPEROXlDE GENERATION AND CALCIb~ INFI~X IN PHNs. H. Katoh, M.Nozaki*, K. Tsurumi* and M; Yamamoto~rk Recently, endogenous mu-opioids have been proposed as i n d i r e c t i n j u r y f a c t o r s following acute b r a i n ischemia on the b a s i s of the t h e r a p e u t i c e f f e c t s of opioid a n t a g o n i s t s and kappa-opioids. We have r e p o r t e d t h a t the binding manner of k a p p a - r e c e p t o r i s r e v e r s i b l y modifyed by r e - p e r f u s i o n following ischemia, and t h a t pathophysio l o g i c a l e f f e c t s of the mu-opioids may be modified and p r o t e c t e d by dynorphin and k a p p a - r e c e p t o r system. On the o t h e r hand, t h e r e i s c o n s i d e r a b l e evidence t h a t an

COMPARISON OF UPPER AND LOWER LIMB SUPERFICIAL VEIN RESPONSIVENESS TO NORADRENALINE A. Luthra. K.R. Borkowski and S.G. Carruthers Noradrenaline (NA) induced constriction of dorsal hand vein (HV) diameter measured by l i n e a r variable differential transformer shows wide intersubject variability. We propose to investigate this variability further by examining i_nn vitro responsiveness of lower limb superficial veins removed during varicose vein stripping or other vascular surgical procedures. Hence it is important to first establish that a relationship exists between i_D_nvivo responsiveness to NA of foot vein (FV) and HV diameter. Doses of NA required to constrict veins by 50 pe'rcent (ED50) and the corresponding concentrations of NA (EC50) were determined at steady state over an incremental range of NA infusions. The subjects were 12 healthy volunteers, 9M, 3F, aged 26 to 38 years. Hand Vein Foot Vein p Diameter (mm) 0.78 ! 0.16 0.54 • 0.14 0.01 EDS0 (ng/min) 5.1 to 121 1.3 to 22 0.01 EC50 (ng/ml) 3.0 to ii0 4.0 to 78 N.S.

activation of PMNs (polymorphonuclear lenkocytes) plays an important role in systemic reaction following local Jschemia such as re-perfusiun syndrome. PMN has opioid receptor on the cell surface, but its function is still uncertain. In this paper, the direct effects of opioid on the function of PMNs were evaluated in vitro. TreatinR PMNs with nM concentration of mu-liRand, morphine, or delta-ligand, DADLE, potentiated development of luminol dependent chemi-!uminescence (LDCL) induced by zymozane or f-MI2. However, these opioids, at high concentration, inhibited the LDCL. In contrast, kappa-ligand, U-50488H or dynorphin, potentiated the LDCL from PMNs in a concentration dependent manner. U50488H and fentanyl inhibited Ca**-influx into PMNs induced by f-MLP. These results suggest that kappaopioid and/or opioid receptor excert its effect on reperfusion post ischemia as an endogenous regulator in CNS but also as a direct modification factor against the function of PMNs. Dept. of Anesthesiol., Matsunami General Hospital, Kasamatsu, Gifu 50]-6|, and Depts. of *Pharmacol. and **Anesthesiol, Gifu Univ. Sch. of Med., Gifu 500, Japan.

The use of EC50 is an effective means of comparing vascular responsiveness to NA in superficial veins and avoids differences in ED50 which may result from variability in basal vein diameter or disposition of NA. Since individual EC50 values were similar for constriction of HV and FV we conclude that the use of superficial vein samples from the lower limb is a valid surrogate for hand vein in further investigation of alpha-adrenoceptor activity and smooth muscle contractile response to NA In vitro. Robarts Research Institute, University Hospital, University of Western Ontario, London ON. N6A 5A5; Victoria General Hospital, Dalhousie University, Halifax NS B3H 2Y9, Canada

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A PRELIMINARY PHARMACOLOGICAL EVALUATION OF THE NOVEL ALPHAI-ADRENOCEPTOR ANTAGONIST UK-52,046 R.F. $ch~fers, P.A. Meredith, H,~ Elliott, J,L, Reid, Alpbal-adrenoceptor antagonist drugs have been shown in shims• experiments to be effective against ischaemia and reperfusion-induced arrhythmias but confirmatory studies in man have been restricted by the potentially adverse effects of blockade of peripheral vascular alpha 1adrenoceptors. UK-52,046 is a novel, selective alpha 1adrenoceptor antagonist, which in animal studies appears to have a greater selectivlty for cardiac than for peripheral vascular alphal-adrenoceptors. We have investigated in 7 normotenstive males (20-36 years) the duration of action of a single i.v. dose (0.5 ug/kg) by measuring blood pressure (BP), heart rate (HR) and the pressor response to the alphal-adrenoceptor agonist phenylephrine (PHE). UK-52,046 had no significant effect on supine or erect BP but there was a slight and significant increase in HR, particularly on standing: 86• with placebo, 97• with UK-52,046. The pressor dose response curve to PHE was significantly shifted to the right for up to 12 hours post dosing with UK-52,046: dose ratios (diastolic BP) were 3.2 (95% CI:~.5 to 2.2) and 1.5 (95Z CI:2.2 to 1.1) respectively at I and 12 hours. Whole blood levels of UK-52,046 measured by HPLC were detectable for up to 12 hours post dosing with a mean whole blood clearance of 63• and a terminal elimination half-life of 5.9• h. For the group there was a significant correlation between the extent of alpha antagonism (PHE dose ratio) and the log dose concentration for both systolic and diastolic BP (r=0.60 and r=0.80, p< 0.01 respectively). Thls study confirms that UK-52,046 has alphal-adrenoceptor antagonist activity in man which is related to drug levels. It was not possible in the present study to confirm "cardioselectivity" but in the absence of profound haemodynamic changes this drug warrants further clinical investigation. University Department of Materia Medica, Stobhill General Hospital, Glasgow G21 3 ~ T, UK.

GLOBAL DEPLETION OF SUPEROXIDE DIMUTASE AND CREATINE PHOSPHOKINASE AT BOTH INFARCTED AND NON-INFARCTED MYOCARDIUM IN RATS D.Z.Dai, P R o n g We have reported that noradrenaline and ATP are depleted at both infarcted (IZ) and non-infarcted zone (NIZ) following ligation of the left coronary artery in rats. The NA depletion response at NIZ wa~ mild but sustained, however, depleting ATP at NIz was temporary. Propranolol and verapamil were effective partially in preventing depletion. Superoxide dimutase (SOD) in myocardium was measured by inhibiting the auto-oxidation of adrenaline. The control value of SOD in the left and right ventricle was 2.72 ~ O . 4 3 & 2.61s 0.2 u/mg WT (s respectively. Measurements were done at 6,12,18,24,48,72 h,9 & 21 d following AMI. The SOD level dropped significantly 6 h at IZ and even lower on 21 d. The decline in SOD level at NIZ (the right ventricle) was not substantial untll 48 h and down to lower level on 9 & 21 d. Decline in creatine phosphokinase (CPK) wa~ also remarkable at both IZ & NIZ. Om 21 d myocardial CPK was well depleted at ~IZ. The free fatty acid (FFA) increased markedly at both IZ within 6-18 h & NIZ at 18 h, thereafter, declined in parallel. The derangement of SOD,CPK & FFA combined with depleting NA could turn NIZ a 'vulnerable substrate' which is responsible to develop malignant arrhytnmias in the presence of stresa. The deranged biochemical situation could be corrected by drug treatment. Depletion of SOD,CPK & NA is sustained at NIZ t suggesting that patients with a chronically infarcted heart healed from an acute episode of a heart attack should be treated for getting rise of these bioactive substances to normal level.

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THE EFFECT OF AUTONOMIC BLOCKERSON HEART-RATE: A COMPARISON BETWEEN ETHNIC GROUPS E.C. Meyer, De K. Sommers, H. Schoeman and J.C. Avenant The effect of atropine on heart-rate may very between individuals at equivalent doses (C.H. Crawford, J. Pharmacol. exp. Ther. 22, 1, 1923). A difference in atropine response has been described between Whites and Blacks (H. McGuigan, J. Am. Med. Ass. 76, 1338, 1921). This study was undertaken to determine whether a possible varying pharmacogenetic s e n s i t i v i t y to atropine's cardiac effects could be demonstrated in a third genetic population, i . e . the Va'Sekele or nomadic Angolan San Bushmen. A single-blind, e t h i c a l l y approved placebo controlled t r i a l was carried out on 10 Bushmen and 8 White volunteers who gave informed consent. Atropine 1,0 mg was administered intravenously to the fasting and supine volunteers. Pulse rate was calculated from ECG tracings taken periodically during the 5 hour t r i a l . The t r i a l consisted of two phases, without and with prior beta-blockade consisting of atenolol 100 mg the evening before and 1 hour prior to atropilne administration. There were significant differences in heart-rate response between the White and Bushmen volunteers at one, 270 and 300 minutes. The early and late bradycardic effects of atropine on the Whites were accentuated by atenolol, while atenolol had no effect on the Bushmen. The Bushmen were s i g n i f i c a n t l y more susceptible to the i n i t i a l and late bradycardic effects of atropine than were the White volunteers. These results support the hypothesis of a varying genetic s e n s i t i v i t y to atropine. Department of Pharmacology, University of Pretoria, P. O. Box 2034, PRETORIA, South Africa, 0001.

PHARMACOLOGICAL STUDY OF CEREBRAL BLOOD VESSELS - NEWLY DEVELOPED MODEL OF PERFUSION SYS17~ T.Ohta, M.Mori, R.Ogawa, M.Tsuji, A.Yasuda, K.Yamada, K.Shimizu, M.Abe* and S.Yokoyama* Pharmacological investigations of vascular reactivity to vasoactive agents using an isometric tensionmeasurement technique have sacrificed the physiological characteristics of the blood vessel as a itminal organ. In order to overcome such handicap, a constant flow perfusion system have been newly developed, with which the function of the vascular smooth muscles is able to investigate independently from the inside and outside of blood vessels. A rabbit basilar artery was isolated as a cylindrical section. The artery was suspended in the new perfusion system, with the inner and outer spaces of the blood vessel completely isolated from each other, and the preparation was loaded with a basic tension of 0.75 g and a basic circulation pressure of 8 mmHg, and an intralt~ninal perfusion was performed at a constant flow of 8 ml/min. The vascular reactivity to the vasoactive agent was measured by using a differential pressure gauge, recording the contraction and dilation of the blood vessel as an increase and decrease of pressure gradiant. The incubating and perfusing solutions were designed to run in different systems to prevent mixing. KCI 30 nJM administered intraluminally caused marked constriction, whereas it induced only a slight constriction by extraluminal administration. On the other hand, Serotonin (5-HT) 2xlO-TM administered intraluminally and extraltmJnally showed similar constrictions. Aeetylcholine (ACh) administered intralt~dJnally and extraluminally in the blood vessel precontracted with 30 ram KCI presented a greater relaxing action when administered intralt~ninally, and it began to show a vasodilating action from 10-6M. Department of Neurosurgery, Osaka Medical School, 2-7 Daigakumachi, Takatsuki City, Osaka, 569, Japan * Nagano Keiki Seisakusho Co.Ltd.

China Pharmaceutical

University,

Nanjing, China.

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SENSITIVITY TO ANTIHYPERTENSIVE ACTION OF HYPOTHALAMIO NOREPINEPHRINE WAS POTENTIATED BY CASTRATION IN SHR T. Kumai, Y. Masubuchi and M. Hirai, Department of Pharmacology, St. Marianna Univ. Seh. of Med., Kawasaki, JAPAN

EFFECTS OF SEROTONIN AND KETANSERIN IN HUMAN PLACENTAL VESSELS J. Marfn. J. Revirie~o. M. S. Fern~indez-Alfonso. M. J. Alonso and J.A. Carrillo The aim of the present study was to analyze the receptors involved in the contractions elicited by 5-hydroxytryptamine (5-HT), as well as the capacity of ketanserin to block different receptors in cylindrical segments of human chorionic arteries and veins. The method used for isometric tension recording has been described elsewhere (MaNn et al, J. Phamx Pharmacol. 31,456, 1979). 5-HT, noradrenaline (NA) and histamine (HIS) caused concentration-dependent contractions, whereas clonidine did not induce effect. 5-HT, mainly, and HIS elicited potent contractions, while NA produced weak responses in some segments (less than 30%). The order of potency (EC50 values) was: 5-HT > NA > HIS. Single concentrations of these agonists produced transient contractions and tachyphylaxis. Segments desensitized to one of the three agonists responded normally to the other two. Gradual desensitization was obtained in segments successively exposed to single or elevated concentrations of NA, 5-HT or HIS. 5-HT contractions were non-competitively blocked by phentolamine (10 -6 and 5 x 10-6M), methysergide (10-7M) and ketanserin (50 nM-1 gM). Ketanserin (10 -6, but not 10-7M) also inhibited the actions produced by NA and HIS. Responses induced by HIS were diminished by diphenhydramine (106M). Low 5-HT (3 x 10-8 or 10-7M) concentrations amplified contractions elicited by NA (10-6M) and HIS (10 6M) in both kinds of vessels. This effect was blocked by 30 min preincubation with ketanserin. These data indicate: (1) 5-HT is the most potent constrictor agent tested; (2) its actions are mediated, at least, by 5-HT2 and alphaladrenergic receptors, and (3) ketanserin, at therapeutic plasma concentrations (around 10-7M, Williams, et al, Br. J. Clin. Pharmacol. 22, 301, 1986), possesses more affinity to block 5-HT2-receptors than to block alphal-adrenergic- and Hi-receptors. Supported by Grants from FISS (88/841) and CAICYT (327/84) Departamento de Farmacologfa. Facultad de Medicina. Universidad Aut6noma de Madrid. C/Arzobispo Morcillo, 4, 28029-MADRID, Spain.

We feund that castration reduced hypertension of SHR in early studies. At present, role of sex hormones in mechanisms of action of naloxone (Nal) as opiate antagonist to systolic blood pressure(BP) were examined. Exp. I: Male and female SHR originated Kyoto Wistar were castrated (Cast)

at 4 weeks old (W) and experiments performed on 28-38W. BP measured by tail-cuff method(KN-208) in eoneious rats. Nal (lOmg/kg,i.p.) was given and the BP was measured at 15-20 min after injection. These results demonstrated that Nal enhanced BP hut, the significant increase appeared in Cast male and female SHR suggesting brain opiates increased by

a tack of n e g a t i v e feedback mechanisms due to Cast, t h u s , the BP led to d e c r e a s i n g . Reasonably Nal a c t to i n h i b i t s the a c t i v i t y of brain opiate system, then the BP appeared as i n c r e a s i n g . Exp. II: Catecholamines(CA) were determined. Male SHR c a s t r a t e d at 4W and experiment performed on 58-82 W. Nal treated a n i m a l s were killed 15 min later. Cerebellum, hypocampus, mid-brain i n e l u d e t h a l a m u s and hyp0thalamus were resected by G1owinski's method. Analysis of CA were made with HPLC. In conolussive remake as correlation between BP and hypothalamie ME in groups of Int and Cast SHE, when hypothalamie ME was increased, the BP showed lower value, namely, while BP increased with Nal, hypothalamic NE decreased. However,though the presser response by Na] was significantly higher in Cast-group than that of int-group,the degree of decreasing was lower in the former , t h u s , s e n s i t i v i t y to a n t i h y p e r t e n s i v e a c t i o n of hypotha-

lamio NE was p o t e n z i a t e d by c a s t . R e s u l t i n g i n f o r m a t i o n with Epi was same as NE as above mentioned. A d d i t i o n a l y , i t should he noted t h a t content of Epi was 1/20 of NE.

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PP 06.78 IMIDAZOLINE PREFERRING RECEPTORS

: A TARGET FOR CENTRAL

ANTIHYPERTENSIVE DRUGS P. Bousquet, G. Bricea, M. Dontenwill, A. Belcourt According to the data obtained from structure-activity relationship studies, we proposed that the central hypotensive effect of imidazoline-like drugs might be mediated through medullary non-adrenergic receptors. In fact, all the imidazolines induced an hypotension when directly injected in the ventrolateral part of the cat's brain stem where no catecholamine or phenylethylamine influenced blood pressure. Binding experiments were performed in order to substantiate the existence of such specific imidazoline preferring receptors in the ventrolateral part of the human brainstem. Using neuronal membranes, prepared from dissected human nucleus reticularis lateralis, the [3H]clonidine binding was saturable, reversible and specific with a K D of 6-7 nM and a Bmax of 65 • 33 fmol/mg protein. The amount of specifically bound labelled clonidine was not displaced by an excess of (-)norepinephrine. At the opposite, imidazolines with a structure similar to that of clonidine were able to compete with [oH]clonidine. Cirazoline proved the most potent competitor. Thus, the human nucleus retieularis region provides the first model of an homogenous population of imidazolinepreferring non-alpha-adrenergic membrane receptors. These receptors might constitute the target for clonidine-like substances triggering their central hypotensive effect. Laboratoire de Pharmacologie Cardiovaseulaire et R4nale, URA D0589 CNRS, et Unit4 de Pharmacologic Clinique, Universit4 Louis Pasteur, ii rue Humann, 67000 Strasbourg, France.

METABOLIC EFFECTS OF FIXED HYDROC~LOROTHIAZIDE/ AMILORIDE COMBINATIONS. COMPARISON OF TWO DOSE LEVELS IN HYPERTENSIVE PATIENTS H. Allonen, P.J. Pentik~inen, G. Aschan The antlhvDertensive dose-response curve of diuretics is less steep than that of adverse metabollc.effects. Therefore smallest effective ant'lhypert,enslve doses should be used i n the treat-sent or nyp@r~enslon~ The antihypertenslve and met abollC e f f e c t s . o i h y d r o c h l o r o t h i a z i a e (HTZ) -amiloriue (A) comDlnanlon in two dose levels were evaluated in a cross-over study in 135 Datients with mild to .moderate byp@~tension. Following a four week run-ln period d[/ring which the pa~ienus received r_nelr p.revlous antih~pertensive m~dication exept for dlure~ics and pQtasslum supplements HTZ/A w a s star~ed in a uose of 50/5 mq or 25/2.5 m g daily wnile o t n e r m e q i c a ~ i o n s were kept unchanged. Treatment perloas lasted 6 weeks an~ the order of the treatments was ranaomlzea. Blood pressure measurements and l a b o r a t o r y tests wereperformed at ends of run-ln and ~reatmen~ Deriods. Low (25/2.5 m g ) and conventional (50Z5 m s) ~ose of HTZ/A reduced blooa pressure by_ I~/~ .r~n.g and 17/9 mmHg .res~ectively~ Ip<0:0001 Zor Do~n) 9 Compared to the Daseline level r-he lOW dose decreased serum potassium (0.I stool/l, 1.4 %, p<0.05) and increased se_~!m urate (33 r&mol/l, 13 ~, p<0.0001) significantly (p<0.0001) less than the_conventional dose (0.2 mmol/l, 4.6 %. p<0.0001 and Dl stool/l, l~ %, p<0.0001, respgctively) 9 Serum t o t a l cholesterol was increased only Dy ~ne conven~lonal dose. n u ] r cholesterol and 5 1 o o d glucose remained unchanged while serum triglycerides were increased (14 %. and 15 % respectively) during the low and conventlonal doses o F HTZ/A. Serum magnesium level snowed a similar decrease ( 4 . 1 % and 5.4 %) during both. doses. Subjective side effects occurea slmilarly a u r l n g D o ~ n treatments. Thus,_ HTZ/A in the low d o s e snowed similar antihvDertenslve effects bus c• less biochemical ~averse effects than the in the conventional dose suggesting t h e use of the low dose in the treat-sent of hypertension. Leiras. Clinical Research, P.O. Box 325 SF-00101 Helsinki. Finland and Third Department of Medicine, University of Helsinki.

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IMPACT OF MIDAZOLAM AND EPHEDRINE ON POSTEXERCISE CARDIOVASCULAR CONTROL C. S t r ~ m b e r g , A. L i n d q v i s t , T. S e p p ~ l ~ , J. V a n a koski P. P a r v i a i n e n and L.A. Laitinen Midezolam (M) a n d e p h e d r i n e (E) h a v e a c t i o n s on autonomic nervous system (ANS) and therefore they probably influence neural circulatory control. ANS modulation of cardiovascular reflexes can be estimated by measuring cardiovascular oscillations. In order to study M or E effects on ANS modulation two different haemodynamic states were elicited: Post-exercise hypoand hypervolaemia~ Single d o s e s o f M 15 mg, E 50 m g or placebo were given to six female volunteers in a double-blind cross-over study. The effect of hypo- and hypervolaemia w e r e s t u d i e d 15 m i n u t e s after cessation of a 30-minute submaximal exercise on treadmill. Bipolar ECG lead and skin blood flow (SkBF) were recorded continuously for five minutes at supine rest, in 70 ~ head-up tilting and -i0 ~ head-down tilting. A low-pass filtered cardiac event series was used to estimate continuously the periodic heart rate variability (HRV, Lindqvist e t al, C a r d i o v a s c u l a r Research, March 1989). A fast Fourier transform program was used to estimate the power spectral density function of periodic HRV and oscillations of SkBF between 0 . 0 1 a n d 0 . 5 0 Hz. E c a u s e d greater periodic HRV but lower oscillations of SkBF than M at supine rest. On the contrary, both during head-up tilt and during head-down tilt M caused a greater effect than E on periodic HRV. However, these latter conditions did not modify drug effects on SkBF. In conclusion, both M and E clearly but differently affect the post-exercise cardiovascular regulation. Department of Pharmacology and Toxicology, University of Helsinki, Siltavuorenpenger i0, S F - O 0 1 7 0 Helsinki, and Research Institute of Military Medicine,CentralMilitaryHospital,Helsinki,Finland

EFFECTS OF ANTIHYPERTENSIVE DRUGS ON EXERCISE INDUCED HEMODYNAMIC CHANGES IN ESSENTIAL HYPERTENSION J. Iwata, S. Kobayashi, K. Yamamoto, F. Deguchi, A. 8akaguchi, M. Tonooka, T. Saito and Y. Inagak~ To investigate the effects of antihypertensive drugs on the hemodynamic changes at exercise, we used Ca antagonists (nifedipine, nicardipine), diuretics (trichrolmethiazide, spironolactone), B-blocker (pindolol) and angiotensin converting enzyme inhibitor (captopril, enalapril) (ACEI) for 4 to 6 months in 32 patients with' mild or moderate essential hypertension. Before and after treatment, patients are subjected to supine bicycle ergometer (1.25 W/kg 6 min) and blood pressure (BP), heart rate (HR) and cardiac output (CO) are measured before and during exercise. In the results, i) All the drugs significantly lowered resting BP and had no effect on HR at rest. 2) Ca antagonist and ACEI reduced total peripheral resistance (TPR), but 6-blocker and diuretics decreased CO and slightly increased TPR at rest. 3) At exercise, Ca antagonist lowered peak BP with enhanced decrease in TPR without reduction of peak CO. 4) Diuretics had small effect on BP change inspite of reduction of peak CO at exercise. 5) Blood pressure and CO response to exercise were suppressed with E-blocker. 6) ACEI had small effect on BP change at exercise. These results suggest that various antihypertensive drugs have different effects on hemodynamics not only at rest hut also at exercise, then it was concluded that exercise induced hemodynamical change should be considered in antihypertensive therapy. The Third Department of Internal Medicine, Chiba University School of Medicine, 1-8-1, Inohana, Chiba City, Chiba 280, Japan

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ORAL CALCIUM LOADING PREVENTS THE MINERALOCORTICOIDINDUCED INCREASE IN BLOODPRESSURE (BP) IN SPONTANEOUSLY HYPERTENSIVE RATS (SHR)

THE EFFECT OF GUANFACINE ON HIGH PLASMA VASOPRESSIN LEVELS IN PATIENTS WITH ESSENTIAL HYPERTENSION

I. P~rsti, H. Wuorela~ P._S~yn~v~lammi, P. M~mmi, P. Arvola, A.-K. Nurmi and H. V a a a ~

At the present time considerable attention is being given to evaluating the possible role of vasopressin (VP) in the pathogenesis of hypertension. An increased VP plasma level has been reported in some patients with mild to moderate essential hypertension (EH). Additionally, yohimbine, a selective alpha-2 adrenoceptor antagonist, has been shown to increase the plasma VP level and blood pressure (BP) in man. The present study was undertaken to evaluate the effects Of chronically administered guanfacine, a centrally acting alpha-2 adren0ceptor agonistr on high plasma VP levels in patients with mild to moderate EH in whom no other causes responsible for elevated plasma VP levels were present. The relations among VP, BP and renin-angiotensfn-aldosterone system (RAAS) were also investigated. Eleven patients (8 women and 3 men aged 62+8 years) with untreated EH and normal renal function were included in the study after a two-week placebo period and kept on a diet containing 120 mmol sodium and 80 mmol potassium daily. In all patients treated once daily with 1 mg of guanfacine for four weeks, the druginduced changes in plasma levels of VP and aldosterone (AL), plasma renin activity {PRA) and BP were evaluated. A marked reduction in plasma VP levels was observed (from 8.21~2.81 to 2.81~1.37 pg/ml, p < 0.001) and this was accompanied by a significant fall in supine mean arterial pressure {from 122.45~4.92 to I03=18~4.46 mmHg, p< 0.0Ol). PRA and plasma AL levels were not significantly altered. The results suggest that guanfacine might suppress VP secretion via alpha-2 adrenoceptors without having any significant effect on RAAS.

We studied the effects and mechanisms of action of calcium (Ca) and deoxycorticosterone (DOC) on BP in SHR. 50 young SHR were divided into 4 treatment groups: control, Ca, DOC and Ca+DOC (mean BP 178 mmHg in each). Ca was given as 1.5 % CaOl2 in drinking f l u i d , and DOC by weekly injections (25 mg/kg s . c . ) . During the 9-week study systolic BP (measured by t a i l cuff) rose in a l l groups, but the increase was greatest in the DOC group (BPs: c o n t r o l 210 f 2, Ca 202 • 3, DOC 235 • 3, Ca+DOC 209 • 3 mmHg, mean f SEM). U r i n a r y e x c r e t i o n s o f Na +, K+ and Ca ++ were enhanced by Ca l o a d i n g . U r i n a r y Ca++ e x c r e t i o n was a l s o i n c r e a s e d i n SHR receiving DOC a l o n e . The plasma l e v e l o f ANF was c l e a r l y i n c r e a s e d by DOC, b u t n o t by Ca o r Ca+DOC. The Na+ and K+ c o n t e n t s o f t h e t a i l a r t e r y were e l e v a t e d i n t h e DOC g r o u p compared t o t h e o t h e r s . Ca l o a d i n g i n creased the activity o f red b l o o d c e l l CaATPase. The i n vitro relaxation of the mesenteric artery by sodium nitroprusside was augmented in the Ca and Ca+DOC groups, whereas DOC alone markedly impaired this relaxation,

These results indicate that the enhanced increase in BP caused by DOC is associated with accumulation of electrolytes and impaired relaxation in vascular smooth muscle. Ca interferes with the BP-increasing effect of DOC by preventing the actions of this mineralocorticoid on electrolytes and vascular relaxation. Department of Biomedical Sciences, University of Tampere, Box 607, SF-33101Tampere, Finland. Grant: Sigrid Jus~lius Foundation, Finland.

E. Berkman, N.T6zHn, Y.Taga and U.Oral

In conclusion, guanfacine appears t0 be an effective drug for the first-line treatment of mild to moderate EH associated with high plasma VP levels. Department of Pharmacology, Medical Faculty of Marmara University, 81326 Haydarpa~a, ~stanbul - TURKEY

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INDENOLOL, A BETA ADRENOCEPTOR BLOCKINGDRUG , VASODILATES VASCULAR DISTRICT THROUGH ITS SYMPATHOMIMETIC(S) ACTIVITY IN ESSENTIAL HYPERTENSIVE PATIENTS. Stefano Taddei, Roberto P e d r i n e l l i , Marzia S~essot, ~iovanni Panarace, Gisela Grothold4~ Antonio S a l v e t t i • S properties may reduce side - e f f e c t s caused by ~adrenoeeptor blocking drugs. Indenolol(1) is a new non s e l e c t i v e ~ - a d r e n o e e p t o r blocking agent whose i n t r i n s i c S p r o p e r t i e s , shown in v i t r o and animal s t u d i e s , could part e c i p a t e to i t s e f f e c t in man. Howeverno data are a v a i l able to support t h i s hypothesis. For t h i s reason we infused I a t three cumulative infusion r a t e s (50,150,500 pg/min x 15 min each) into the b r a c h i a l a r t e r y in n=9 hypertensive patients. F blood flow ( F B F , venous plethysmography), MAP and HR were continously monitored. Active drug infusion was preceded by s a l i n e infusion (S, 0.2ml/min x 15 min) which did not change FBF (from 3.3• to 3.3• MAP and HR. During I infusion a t 50 }tg/min, FBF did not change (from 3.3• to 3.3• but F v a s o d i [ a t i o n toB-adrenoceptor stimulation by isoproterenol (0.2 },g/min x 3"min; n=] preliminary case) was abolished, f u r t h e r confirming the ~-blocking p r o p e r t i e s of the drug. At the g r e a t e r infusion r a t e s I increased FBF (150 pg/min: from 3.3• to 4.3~1.9, p<.05 vs S; 500 pg/min: from 4.3+1.9 to 7.7+2.7, p<.0l vsS). This v a s o d i l a t i n g action was~mediated b~0-adrenoceptor stimulation since it was abolished by pretreatment with propranolol (]00 ~g/min x 15 min), a ~-blocker devoid of S activity (S: 3.3• PRO: 1 50: 2.8• 150: 2.7• 500: 3.9• n=5 additional pts). Thus I directly vasodilates forearm arterioles, when infused into the brachial artery, and this effect is abolished by previous ~ -blockade. These data demonstrate the intrinsic S actlvity of I also in man which may possibly contribute to its therapeutic action in man, Hypertension Unit, I Clinica Medlca, University of Pisa, 56]00 PISA, Italy.

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HAEMOSTASIOLOGICAL PARAMETERSAND CIRCADIAN BLOOD PRESSURE VALUES IN HYPERTENSIVESON CHRONIC CELIPROLOL ADMINISTRATION A.Halabi, K.-H. Zurborn, P. Kaiser. W. Kirch; I. Medzinische K l i n i k Christian-Albrechts-Universit~t, Kiel, FRG Celiprolol is a r e l a t i v e l y new cardioselective betablocker with i n t r i n s i c sympathomimetic a c t i v i t y . Non-cardioselect i v e betablockers enhance thrombocyte aggregation and decrease f i b r i n o l y t i c a c t i v i t y of hypertensives ( I ) . Therefore, aim of the present study was to investigate the influence of c e l i p r o l o l on haemostasis. In a placebo-cont r o l l e d study 12 patients with a r t e r i a l hypertension were treated with 200 mg c e l i p r o l o l once d a i l y for 1 month (8 men, 4 women; mean age 55 • 9 y r s . ; body weight 78 t lOkg; t SEM, d i a s t o l i c blood pressure values~95 mm Hg).Atthe end of a 3-4 weeks lasting placebo period and following 4 weeks of c e l i p r o l o l treatment, circadian blood pressure values (Accutracker, Oxford Instruments, Wiesbaden, FRG), haemostasiological parameters (fibrinogen, f i b r i n o p e p t i d A , AT I I I , plasminogen, p l a t e l e t factor 4, PTT, Quick), venous occlusion plethysmography and viscoelastometry ( o s c i l l a ting capillar-rheometer, Chempro GmbH, Hanau, FRG) were determined. Celiprolol led to a s i g n i f i c a n t decrease of the circadian blood pressure p r o f i l e and of heart rate. React i v e hyperaemia as a parameter of limb perfusion was 18.3• 4 ml/lO0 ml tissue/min after placebo and 15.2• 3.1 ml/lOOml tissue/min following c e l i p r o l o l treatment. In viscoelastomerry no s i g n i f i c a n t differences between placebo and c e l i prolol were seen. Also haemostasiological parameters including thrombocyte function were not s i g n i f i c a n t l y altered by c e l i p r o l o l compared to placebo. In conclusion, c e l i p r o Ioi as cardioselective betablocker had no s i g n i f i c a n t influence on parameters of plasmatic haemostasis, thromboc~e function and viscoelastometry of hypertensives. I. Winter, K.: The effect of B-blockade on p l a t e l e t function and f i b r i n o l y t i c a c t i v i t y . J Cardiovasc Pharmacol I0:$94-$98 (1987)

SYSTEMIC B-BLOCKADE BY LOW TIMOLOL CONCENTRATIONS: IMPLICATIONS FOR OCULAR THERAPY E. l i s a l o , T. Kaila, R. Huupponen, S. Karhuvaara, FT-lTa-vula, L. Salminen A highly sensitive radioreceptor assay of timolol (50 pg/ml) was used for measuring systemic absorption of the drug after ocular application of 30 ql of 0.5 % timolol (T) to both eyes in 9 vQlunteers. The mean peak plasma level of 810 pg/ml (range 350 - 1550 pg/ml) was achieved already in 15 minutes. After 4 hours the mean concentration was 490 pg/ml. Plasma concentrations of T needed for e f f e c t i v e Bblockade were studied in 6 volunteers. Isoprenaline (I) was infused intravenously in increasing doses u n t i l the heart rate increased by 25 beats/min (125-test). After basal r e g i s t r a t i o n , 0.5 mg of T was infused intravenously during 15 minutes. Blood samples were drawn for repeated determinations of plasma T, cAMP, potassium and magnesium. 125-test was repeated 15 minutes and 4 hours a f t e r T infusion. The mean plasma T concentrations were 790 • 230 at 15 minutes and 390.• 170 pg/ml at 4 hours. T strongly increased the amount of I required for the rise of heart rate. I t also nearly t o t a l l y abolished the increase in cAMP caused by I. The concentrations of potassium and magnesium remained unchanged throughout the study. I t is concluded that T already at low plasma concentrations (450 - 860 pg/ml) induces an e f f e c t i v e B-blockade. These levels are similar to those achieved and maintained at least 4 hours after ocular application of the drug. Systemic B-blockade is obvious a f t e r local ocular a p p l i cation. Departments of Clinical Pharmacology, Pharmacology and Ophtalmology, University of Turku, SF-2520 Turku, Finland

I. Medizinische K l i n i k , Christian-Albrechts-Universit~t Schittenhelmstr. 12, 2300 Kiel l

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EFFECTS OF D1 AND D2 DOPAMINERGIC AGONISTS ON BLOOD PRESSURE AND PLASMA CATECHOLAMINES IN PARKINSONIANS G. Durrieu, J.M. Senard. O. Rascol, M.A. Tran, J.L. Montastruc and P. Montastruc The effects of several dopaminergic agonists (DI: CY 208-243, D2: bromocriptine and mixed D1 / D2 : levodopa) on lying and standing blood pressures (BP) and heart rate (HR) as well as on plasma catecholamine (CA) levels were investigated in patients with Parkinson's disease (PD). The DI or the D2 agonist significantly (p<0.05) decreased BP, HR and plasma noradrenaline (NA) (but not adrenaline (A)) levels in lying position, whereas levodopa (+dopa decarboxylase irihibitor) remained without effect. After 1 min in standing position, CY208-243 (but not bromocriptine or levodopa) significantly (p<0.05) decreased BP; the three drugs significantly potentiated the standing-up-induced increase in HR.The rise in plasma NA elicited by standing up was significantly lower in patients treated by CY208-243, bromocriptine or levodopa than in controls. These results confirm the sympatholytic properties of the D2 agonist bromocriptine and describe a similar action for the D1 agonist CY 208-243. Since CY reduced Bp, HR and plasma CA, its cardiovascular action may involve the central nervous system, thus suggesting a role for central D1 receptors in the regulation of sympathetic tone. Lab. de Pharmacol. M6dicale et Clinique, Inserm U317, Fac. de M6decine,37Al16es J Guesde,31073 Toulouse France

ATIPAMEZOLE, A NOVEL ~2-ADRENOCEPTOR ANTAGONIST, INCREASES PLASMA CATECHOLAMINES AND BLOOD PRESSURE IN HEALTHY MALE VOLUNTEERS S. Karhuvaara, A. Kallio, M. Scheinin and H. Scheinin Single doses {i0, 30 and 100 mg) of anipamezole (MPV-1248), a novel potent and selective ~2adrenoceptor antagonist, or sallne placebo were administered to six healthy male volunteers as 20 min intravenous infuslons in a randomized double-blind cross-over phase I study. Infusion of i00 mg atipamezole clearly elevated both systolic and diastolic blood pressure (from 112+10/55+6 mmHg to 130~17/78~ii mmHg, mean• whereas the rise was significantly lower after 30 mg and not distinguishable from placebo after 10 mg. Heart rate was increased in one subject after the highest dose; otherwise it remained unchanged during all sessions. The mean plasma noradrenaline concentrations were increased by 440 % after i00 mg, and by 137 % after 30 mg. The mean concentrations of adrenaline in plasma w e r e significantly elevated only after i00 mg (from 0.092+0.049 to 0.57~0.71 nmol/l). Subjective drug effects were seen mainly after the highest dose and included restlessness, coldness and sweating of hands and feet, tremor, shivering and increased salivation. The effects are compatible with the presumed e2-adrenoceptor antagonistic mechanism of action of the drug, with blockade of presynaptic inhibitory autoreceptors leading to enhanced noradrenaline release, and are in general concordance with the results obtained earlier with other ~2-adrenoceptor antagonists, yohimbine and idazoxan. Department of Pharmacology, University of Turku, Kiinamyllynkatu 10, SF-20520 Turku, Finland.

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ABSENCE OF HYPERTENSION DESPITE CHRONIC INCREASE I N SYMPATHETIC TONE: DESENSITIZATION OF ALPHA ADRENERGIC RECEPTORS. J.M. Senard, M. Berlan, P. Valet, G. Durrieu, L- Estan, M.A. Tran, M. Garrignes* and J.L. Montastmc

EFFECT OF T A L I N O L O L ON E X E R C I S E T A C H Y C A R D I A IN H E A L T H Y SUBJECTS M.Eallweit, R.G.Alken, H . H ~ l l e r T a l i n o l o l , a b e t a - l - s e l e c t i v e a d r e n o c e p t o r blocking agent, is r e c o m m e n d e d to be a d m i n i s t e r e d at individual doses t.i.d. Due to controversial results p u b l i s h e d on kinetic p a r a m e t e r s at various doses by d i f f e r e n t a n a l y t i c a l techniques and equivocal clinical o b s e r v a t i o n s concerning the duration of action of Talinolol further i n v e s t i g a t i o n seemed to be appropriate. Talinoioi was given to eight h e a l t h y subjects at single oral doses of 50 and 150mg, at a placebocontrolled design and d o u b l e - b l i n d conditions, propranolol (75mg orally) was given as a positive control. P a r a m e t e r of b e t a - b l o c k a d e was the e x e r c i s e - i n d u c e d change in pulse rate, systolic blood pressure and double p r o d u c t at a standard exercise test. The effect of a single dose of 50mg Talinolol proved to be e f f e c t i v e for about 6h p.d. but did not reach m a x i m a l i n h i b i t i o n Of exercise response. The effect of 150mg Talinolol did exhibit a m a x i m a l level and was detectable for more than 24h p.d. Thus, a single dose per day might be a p p r o p r i a t e for a therapeutic regimen in hypertensives. Institute of Clinical Pharmacology, HumboldtUniversity, POB 140, Berlin, i040, GDR

Adrenergic receptors and receptor-mediated function are reduced by chronic exposure to eatecholamines. This phenomenon, well known for beta-receptors, remains controversial for alpha-adrenoceptors. We describe a case of increased levels of plasma noradrenaline without hypertension associated with desensitization of alpha-adrenoceptors. A 44 years old woman presented chronic and stable high levels of plasma noradrenaline (NA: 883 to 1208 vs 269-+78 pg/ml in 5 controls) without any major change in adrenaline (65 to 100 vs 48-+22 pg/ml). Urinary eatecholamines or metabolites were in normal ranges. Blood pressure (BP) and heart rate (HR) were normal. Infusion of increasing doses of NA was unable to induce a change in BP or HR untill the rate of 41/ag/min. In controls the dose necessary to increase BP for 15 mmHg was 24 lag/min. Yohimbine administration (0.2 mg/kg p.o) increased plasma NA from 958 to 2150 pg/ml in the patient whereas the same dose rose NA from 269+78 to 507-+104 pg/ml in controls. In both cases, neither blood pressure or heart rate were modified after yohimbine administration. Platelet alpha2-adrenoceptors evaluated by [3H]-yohimbine specific binding showed a significantly lower level (110 fmoVmg protein) as compared to controls (190+17 fmoVmg protein) without any modification in Kd. The results show that sustained increased in plasma NA can induce a desensitization of alpha-adrenoceptors as reflected by lack of response to noradrenaline infusion and decreased platelet alpha2-adrenoceptors. This phenomenon can explain the lack of arterial hypertension despite an increased sympathetic tone. Laboratoires de Pharmacologie Medicale et Clinique et de Physiologie*, INSERM U317, Faculte de Medecine, 31073 Toulouse cedex, France.

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NORADRENALINE DOSE-RESPONSE AND CONCENTRATIONR E S P O N S E R E L A T I O N S H I P S IN D O R S A L H A N D V E I N

C A T E C H O L A M I N E R E L E A S E A N D LIPID M O B I L I Z A T I O N INDUCED BY YOHIMBINE ADMINISTRATION IN OBESE WOMEN M. Berlan, M.A. Tran, M. Garrigues, R.. Flores and M. Lafontan. The utilization of alpha2-antagonists could represent a lipid mobilizing stategy for the improvement ofweight loss in obese patients submitted to energy restriction. These drags can increase the sympathetic tone through central and presynaptic alpha2 adrenoceptors antagonization and promote a blockade of the antilipolytic alpha2 adrenoceptors located on adipocytes. In 6 fasting non obese women (age: 35.5-+2.7 years, weight: 56.2-+2.5 kg, body mass index: BMI=20.2-+0.5) the mean plasma non-esterified fatty acids (NEFA) levels was: 411-+52 riM. Oral yohimbine (YOH) administration (0.2mg/kg) significantly increased plasma NEFA during the time course of the experiment (240 min) (+236-+27 rim 60 min after YOH ) when compared to placebo administration. Plasma noradrenaline levels (NA) (hut not adrenaline) were increased (507-+104 vs 269-+78 pg/ml 60 min after YOH). There was no significant action on heart rate and blood pressure. Neither plasma insulin or glucose levels were modified. Ten obese w o m e n (age: 37-+3.6 years, weight: 94-+5.1 k g , BMI=36.4-+2.1) exibited fasting plasma NEFA levels signiticantly higher than non-obese (528-+32 riM). YOH provoked an increase in plasma NEFA which was not significantly different to that observed in non obese subjects (+345-+41 rim 60 rain after YOH). Plasma NA increased in the same proportions than in controls (496-+69 vs 243-+25 pg/ml). Cardiovascular parameters remained unchanged. No modification was observed in plasma insulin or glucose levels. Five of the 10 obese patients agreed 1o receive 3x4 mg YOH daily during 1 month, without modifying their caloric intake, and to perform a second YOH test at the end of the treatment. The acute response to YOH was not modified: plasma NEFA level increased from 562+71 to 858-+ 111 rim vs 476-+ 16 to 705-+86 !aM and plasma NA levels increased from 200-+32 to 472-+66 vs 268-+39 to 537+93 pg/ml. Apha2-antagonists can increase lipid mobilization through a rise in sympathetic tone inducing a beta-adrenergic mediated increase in lipolysis at adipose tissue level. This effect is not reinforced in obese. The mechanims underlying the lipomobilization are not submitted to tolerance after chronic administration of YOH. INSERM U317 Laboratoire de Pharmacologic Medicale et Clinique et de Physiologic, Faculte de Mddecine,31073 Toulouse cedex, France.

K.R. B o r k o w s k l . A. L u t h r a and S.G. C a r r u t h e r s There is m a r k e d i n t e r s u b j e c t v a r i a b i l i t y , unr e l a t e d to age or gender, in the d o s e of noradrenaline (NA) r e q u i r e d to c o n s t r i c t d o r s a l hand v e i n (HV) d i a m e t e r by 50 p e r c e n t (ED50). Differences in d i s p o s i t i o n of NA by uptake, washout and m e t a b o l i s m may account for this v a r i a t i o n . We have, t h e r e f o r e , i n v e s t i g a t e d the r e l a t i o n s h i p b e t w e e n NA c o n c e n t r a t i o n and HVD and compared the concentration required to p r o d u c e 50 p e r c e n t v e n o c o n s t r i c t i o n (EC50) with the E D S 0 at s t e a d y s t a t e f o l l o w i n g i n c r e m e n t a l NA infusions. HV r e s p o n s e was m e a s u r e d by linear variable differential transformer (LVDT). P l a s m a NA was m e a s u r e d by HPLC/ED. The s u b j e c t s were 15 h e a l t h y v o l u n t e e r s 13M, 2F, aged 21 to 38 years. ED50 ranged from 3.4 to 120 ng/0.1 ml/ min. E C 5 0 of NA in p l a s m a r a n g e d from 1.4 to ii0 ng/ml. T h e r e was a p o s i t i v e linear r e l a t i o n s h i p b e t w e e n dose and c o n c e n t r a t i o n in each s u b j e c t (r=0.76 to 0.96, p<0.0l). The slopes of the lines r e l a t i n g dose and c o n c e n t r a t i o n r e f l e c t NA d i s p o s i t i o n w i t h i n the vein, r a n g i n g from 0.53 to 1.76 ml/min. The use of EC50 is an e f f e c t i v e means of e x a m i n i n g the r e l a t i o n s h i p b e t w e e n N A concentration and HV constriction. Although there is a 3-fold range in d i s p o s i t i o n of NA, the wide range of EC50 was s i m i l a r to the range of ED50 o b s e r v e d in this and e a r l i e r studies. We C o n c l u d e that d i f f e r e n c e s in NA k i n e t i c s are r e l a t i v e l y u n i m p o r t a n t , but d y n a m i c a s p e c t s of alpha-adrenoceptor function and/or smooth muscle c o n t r a c t i l i t y a p p e a r to a c c o u n t for the wide intersubJect variability. R o b a r t s R e s e a r c h Institute, U n i v e r s i t y H o s p i t a l , U n i v e r s i t y of W e s t e r n Ontario, London, ON N 6 A 5A5; V i c t o r i a G e n e r a l Hospital, D a l h o u s i e U n i v e r s i t y , H a l i f a x NS B3H 2Y9, C a n a d a

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PHARMACOKINETICSAND PHARMACODYNAMICSOF YOHIMBINE IN NORMAL VOLUXITEF/{S T. Heclner, J. Hedner, A. Pettersson and B. Persson

SIMILARITY BETWEEN HUMhN AND hNIMhL ALPHA-2 hDRENOCEPTORS J.R. OocherL~ and S. Eonnau_zhton. V a r i o u s a u t h o r s have s u g g e s t e d t h a t t h e r e may be s p e c i e s differences in a l p h a - 2 a d r e n o e e p t o r s or t h a t p r e - and postjunctional a I p h a - 2 a d r e n o e e p t o r s may d i f f e r . In t h i s study we have cnmpared t h e p o s t j u n c t i o n a i alpha-2 a d r e n o c e p t o r s of the human saphenous v e i n and human piatelet with the p r e j u n c t i o n a l a l p h a - 2 a d r e n o c e p t o r s of t h e r a t a t r i u m and r a t v a s d e f e r e n s , employing a s e r i e s of a l p h a - 2 a n t a g o n i s t s i n c l u d i n g yohimbine and t h e t e s t compound SK ~ F 104078 uhich i s r e p o r t e d t o show selectivity f o r p o s t j u n c t i o n a l a l p h a - 2 a d r e n o c e p t o r s . In human saphenous v e i n , c o n t r a c t i o n s t o n o r a d r e n a l i n e a r e mediated by a l p h a - 2 a d r e n o c e p t o r s : yohimbine and SK & F 104078 had ph 2 v a l u e s a g a i n s t n o r a d r e n a l i n e of 7.40 and 6.33 ( - l o g M), r e s p e c t i v e l y . In human p l a t e l e t membranes, ~ d v a l u e s of 8.00 and 6.73 were o b t a i n e d f o r yohimb~ne SK & P 104078, r e s p e c t i v e l y , f o r d i s p l a c e m e n t of Hyohimbine b i n d i n g . In r a t vas d e f e r e n s , p r e j u n c t i o n a l ph v a l u e s of 7.50 and 6.39 were o b t a i n e d f o r y o h i a b i n e an~ SK & F 104078, r e s p e c t i v e l y , at antagonising the prejunctional inhibition by t h e a l p h a - 2 a d r e n o e e p t o r a n t a g o n i s t x y l a z i n e of i s o m e t r i c c o n t r a c t i o n s to a s i n g l e stimulus. In r a t a t r i a ; yohimbine and SK & F 104078 had prejunctional EChO v a l u e s ( c o n c e n t r a t i o n p r o d u c i n g 30Z p o t e n t i a t i o n of s ~ l m u l a t i o n - ~ v o k e d o v e r f l o w of t r i t i u m An tissues p r e - i n c u b a t e d u i t h H - n o r a d r e n a l i n e ) of 7.89 and 6.68, respectively. Other a n t a g o n i s t s i n v e s t i g a t e d a l s o failed to distinguish betmeen human p o s t j u n c t i o n a l and rat prejunctional alpha-2 adrenoceptors (e.g. prazosin Ph v a l u e s mere 6.20 in t h e r a t y e s d e f e r e n s and 6.~ in t h e human saphenous v e i n ) . Hence, i t i s concluded t h a t human p o s t j u n c t i o n a i a l p h a - 2 adrenoceptors are similar to prejunctional alpha-2 adrenoceptors in the r a t , at least for the tissues examined in t h i s s t u d y . Bepartment of C l i n i c a l Pharmacology, Royal C o l l e g e of Surgeons in I r e l a n d , Dublin 2, I r e l a n d

The indolalkaloid yohimbine is an ~z-adrenergic antagonist which is derived from several biological sources. Although yohimbJ~nehasbeen known for over 100 years, the pharmacologyand pharmacokinetics in man is not well described. We have studied the plasma concentrations as well as the autonc~ic effects of intravenous yohimbine (0.25 mg/kg b.w) to 10 normal volunteers. Blood pressure (HP) and heart rate (HI{) were measured by automatic techniques and stroke volt,he (SV) and cardiac output (CO) were estimated by in~0edance cardiography. Subjective autonomic effects were estimated by visual analogue scales (VAS). Yehimbine was rapidly eliminated from plasma and elimination half life ranged from 25 to 41 mJ_n while one subject had a half life of 150 min. Systolic and diastolic BP was increased by approximately 10% during 30 min after the injection, while HI{, SV and CO r e ~ i n e d unchanged. Subjective effects included increased sweating, cold hands and feet, and "wet dog shakes". These effects appeared within 5 min and generally disappeared within 30 rain. The data suggest that yohinlbine has a short half life corresponding to its transient haermx~ynamic subjective autonomic effects. Dept of Clinical Pharmacology, Sahlgrenska University Hospital, S-413 45 Gothenburg.

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EFFECTS OF DENOPAMINE ON ORGAN HEMODYNAMICS Y. Morioka, H. Nonaka, K. Hayashi, N. Shiomi, M. Saito, K. Ban? K. Houda r K. Yoshimura, A. Nakatani, A. Kamimoto~ N. Tsujimoto, A. Ueda, Y. Morita, K. Okada and H. Ishikawa The effects of denopamine (D), a 51-receptor stimulator, on the hemodynamics of various organs were investigated. Methods: Catheters were inserted into the aorta, inferior vena cava and portal vein, and electromagnetic flowmeters were fitted to several vessels of anesthetized mongrel dogs. Then a normal (i ~g/kg/min) or a high dose (i0 Dg/kg/min) of D was injected intravenously. Results: l) The normal dose of D increasedcardiac output (CO), but caused no change either in heart rate (HR) or in arterial blood pressure (ABP). In contrast, at the high dose of D, CO and HR increased and ABP tended to decrease. 2) The local effects of the normal dose were increased cervical blood flow (CBF) and femoral blood flow (FBF), but superior mesenteric blood flow (SMF), hepatic blood flow (HBF), portal blood flow (PBF) and renal blood flow (RBF) did not change. The high dose caused an increase in CBF, FBF and RBF, a decrease in SMF ~ d ~ F , and had no effect on PBF. 3) Overall, D had no significant influence on renal function; only a tendency for C P A H t O increase and a tendency for Ccr and filtration fraction to decrease were observed. Conclusion: Since CO increased and BP showed no clear change, it appeared that D lowered vascular resistance. However, changes in local blood flow differed for the normal and high doses, so, in the clinical application of this drug, it is necessary t o consider organic correlations. Since D tended to increase CpAHand to decrease Ccr, the possibility that efferent arterioles were relaxed more than afferent arterioles was suggested. The First Department of Internal Medicine, Nara Medical University, 840, Shijo, Kashihara, Nara, Japan

DIFFERENTIAL RATES OF ~ -

and ~-ADRENOCEPTORDOWN-REGULATION FOLLOWING,~HRONICA~MINISTRATION OF CATECHOLAMINES.

N.M. Deighton ", C.A. Hamilton and J.L. Rei d The rate of adrenoceptor down-regulation has been implicated in certain c l i n i c a l situations, for instance, the bene f i c i a l actions of some antidepressant drugs may be p a r t l y due to a progressive ~-adrenoceptor (AR) desensitization (Dye et a l . , Br.J.Pharm.80:665,1983). Also the degree of heart f a i l u r e has been associated with a progressive decrease in ~-AR number (Fowler et a l . , Circ. 74:1290,1986). L i t t l e is known concerning the mechanisms which control the rate of AR-loss.We, therefore, studied the time-course of ~-and 5-AR desensitization following long-term exposure to adrenaline and noradrenaline. Male New Zealand white rabbits (2.5-3.5 kg b.w.) received in vivo intravenous infusions of adrenaline (0.05 ~mol/kgT6~--6?--noradrenaline (0.09 ~mol/kg/h) or vehicle (0.1% ascorbate) for 0.5, I, 2, 3 and 10 days via osmotic minipumps (n~6). Five to tenfold elevations in circulating catecholamines were achieved in a l l catecholamine-treated animals. At the end of the infusions p l a t e l e t and renal m~-AR were assessed by [3H]yohimbine binding and c ~ i a c ~nd lung ~-AR (mainly ~I-AR in the rabbit) by ( - ) - [ l]iodocyanopindolol binding. A decrease in cardiac (40%) and lung (32%) ~-AR numbers was evident within 24h of adrenaline- or noradrenaline-infusions; however,a similar reduction (36 %) in p l a t e l e t ~-AR was not apparent unti! the end of 3 days adrenaline-in~usion; s i m i l a r l y renal ~-AR number had decreased (21%) only after 3 days of nbradrenaline-infusion. These results indicate that endogenous catecholamines down-regulate ~ and ~-AR at d i f f e r e n t rates. Thus, agonist efficacy anff d i f f e r e n t i a l accessibility of receptors to agonists may both influence the time-course of AR-degradation. University Department of Materia Medica, Stobhill General Hospital, Glasgow G21 3UW, U.K. *) Present address: Med. Klinik & P o l i k l i n i k , Abt. Nieren& Hochdruckkranke, Universit~tsklinikum Essen, Hufelandstrasse 55, D-4300 Essen, FRG.

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ANALGESIC A C T I V I T Y C F B^ A G O N I S T S . J.K. GR~R, H. P O P L I ~ Z p . S~%,AK Analgesia may be adrenergic in nature was reported by Beckett in 1952. Thirty healthy volunteers ( b o t h m a l e 'and f e m a l e s ) r a n g i n g between 25-50 years were included in this study. Pain was induced by standard cold technique. Study was carried out in double blind c r o s s o v e r d e s i g n . G l u c o s e },as u s e d as p l a c e b o and acetylsalicylic a c i d ( 3 0 0 mg) as s t a n d a r d control. Onset of pain was reCorded in s e c o n d s , b e f o r e a n d 30 m i n u t e s a f t e r d r u g adminstration. Average onset in males was 167.45 + 10.8 seconds while in females it %as 197.45 ~ 14.8 secOnes before and 351.7 § 23.9 a n d 4 0 7 ? 6 ~ 4 1 . 3 s e c o n d s a f t e r 2.5 a n d [ . 0 m g of oral terbutaline respectively. Asthalin (2 a n d 4 mg) p r o d u c e d s i m i l a r a c t i v i t y . V a l u e s i n t h e p l a c e b o a n d d i s p r i n t r e a t e d g r o u p s %~ere 205.1 + 71.2 and 255.3 + 11.6 seconds. b[ifedip--ine (i0 mg) a n d ~ e r i ~ s h y ! l i n e (i00 m g ) increased the duration which was statistically not significant (p> 0.05). Analgesic effect of terbutaline and asthalin was found to be significant. Males %ere found to be more sensitive to pain than females. Analgesic effect of B2 agonist ~as more marked in asthmatic p~tients. Stimulation of B 2 receptors in brain probably produces analgesia.

THE E F F E C T S OF S U L F A T E D O P A M I N E C O N J U G A T E ON I S O L A T E D P E R F U S E D RAT H E A R T A N D R O L E OF A T R I A T. OHUCHI, Y. ISHIMURA, K. MINAKUCHI, K. TERAOKA, M. OKA, S. MATSUOKA and H.A.H.M. Mahbubul A l a r g e a m o u n t of d o p a m i n e ( D A ) , m o r e t h a n 70% of the t o t a l c a t e c h o l a m i n e s ( C A ) , c i r c u l a t e s in conjugated form in the plasma. This fact i n t e r e s t s us g r e a t l y and lead us to i n v e s t i g a t e its o r i g i n and p h y s i o l o g i c a l s i g n i f i c a n c e . We s t u d i e d the e f f e c t s of s u l f a t e D A c o n j u g a t e , s y n t h e s i z e d c h e m i c a l l y b y the m e t h o d of J e n n e r and Rose (Biochem. J. 135, 109, 1973) on i s o l a t e d p e r f u s e d rat h e a r t and d e m o n s t r a t e d that DA-4-sulfate had a positive inotropic a c t i o n (increase in d e v e l o p e d t e n s i o n , m a x i m a l rate of contraction and maximal rate of relaxation) o n the rat heart. These effects w e r e q u i t e s i m i l a r to t h o s e of D A i t s e l f e x c e p t that the c o n j u g a t e s h o w e d a lag t i m e b e f o r e the onset of the a c t i o n and intact atria were essential for the activity. The results s u g g e s t e d t h a t D A s u l f a t e h a d no d i r e c t e f f e c t on the v e n t r i c u l a r m u s c l e , b u t was c o n v e r t e d w i t h i n the a t r i a l t i s s u e s into free D A w h i c h m a y be r e s p o n s i b l e for the p o s i t i v e i n o t r o p i c action. The f u r t h e r s t u d y w a s c a r r i e d out to a s c e r t a i n w h e t h e r d e c o n j u g a t i o n of D A - s u l f a t e a c t u a l l y o c c u r s in the heart. DA-4-sulfate was c o n s i d e r a b l y d e c o n j u g a t e d to D A in the a t r i a l tissues [11.76 • 0.83 (n=5) n m o l e s / g / m i n (• S.D.)] b u t not in the v e n t r i c u l a r t i s s u e s [0.95 • 0.08 (n=5) n m o l e s / g / m i n (• S.D.)] of the dog. The r e s u l t s c o i n c i d e w i t h our s u g g e s t i o n that DA conjugate acts on the h e a r t after d e c o n j u g a t i o n in the a t r i a l tissue, Department of Pharmacology, Tokushima University School of Medicine, 3-18-15 K u r a m o t o , T o k u s h i m a 770, J A P A N

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COCAINE BLUNTS THE BARORECEPTOR REFLEX IN RATS R. Trouv& A. KvDson. C. Latour and G. Nahas. Cocaine, a noradrenaline uptake inhibitor, liberates catecholamines, and may cause cardiac and cerebral damage through catecholamines and angbtensin II overflow. These effects may be reversed with calcium channel inhibitors such as Nitrendipine, Diitiazem, Flunarizine, Nicardipine or an association of angiotensin converting enzyme inhibitor (enalaprilat) and diazepam. However the lack of efficiency of Verapamil in centroiting cocaine hypertensive cdsis, demonstrates that the peripheral effects of catecholamines are only partially responsible for the observed disturbances and that angiotensin II or/and baroreceptor reflex impairment are involved. In order to test the latest hypothesis, 2 groups of 6 rats maintained under anesthesia,one control and the other receiving 50 mg/kg cocaine IP at the beginning of the experiment, were fitted with a caudal arterial catheter and connected to a computerized system monitoring cardiovascular parameters. The baroreceptor reflex was challenged by clamping both common carotid arteries for 2', 4 times over a 30' period, and measuring the resulting maximal variations in arterial pressure. An Anova (analysis of variance) performed on arterial pressures before clamping, showed no significant difference between the control and treated groups. Following the first clamping, the mean increases in pressure were 48.8 and 9.7 mm Hg respectively and 32 and 12.2 mm Hg for the last clamping. An Anova performed on the maximal variation in pressure following clamping indicated a significant difference (p<0.0001) between both groups. In order to ascertain that this result was only due to cocaine effects on the baroreceptor reflex pathway, and not to any difference in pressure inside the clamped carotids between groups, 2 groups of 6 rats treated as previously (control and cocaine) were fitted with a catheter in the left carotid artery. Two successive bilateral clampings for 2' were performed. No difference in pressures before clamping was found. The drops in arterial pressures were not different in the control and in the cocaine treated group. An Anova on minimal carotid pressures after clamping did not exhibit any difference between groups (p<&41). These experiments provide evidence that beside the well known sympathetic overflow, cocaine may also impair the arterial pressure control through inhibition of the baroreceptor reflex pathway. As angiotensin II is also known to inhibit the baroreceptor reflex, these results may be another illustration of the rapid disturbance of angiotensin II levels induced by cocaine. Department of Anesthesiology, Columbia University, New York, USA and Laboratoire de Pharmacologie et Toxicologie, INSERM, Paris, France.

INHIBITION OF NORADRENALINE RELEASE FROM CORTICAL SYNAPTOSOMES AND STIMULATION OF ( N A + + K + ) - A T P A S E A C T I V I T Y BY C L O N I D I N E IN RATS T_:_.N i s h i k a w a ~ T. T e r a m o t o and S. S h i m i z u Effects of c l o n i d i n e on noradrenaline (NA) r e l e a s e from rat e e r e b r o c o r t i c a l synaptosomes and on the synaptosomal (Na++K+)-ATPase activity were determined. Preparation of synaptosomes and assay of (Na++K+)-ATPase a c t i v i t y were c a r r i e d out as d e s c r i b e d b e f o r e (T. N i s h i k a w a et al., Biochem. Biophys. Res. Commun. 126, 893, 1985; Jap. J. Pharmacol. 47, 143, 1988). C l o n i d i n e (10-5-10 -7 M) caused a d g s e - r e l a t e d i n h i b i t i o n of e n h a n c e d p r e l a b e l e d [JH]NA r e l e a s e from s y n a p t o s o m e s e v o k e d by high c o n c e n t r a t i o n of K + and this i n h i b i t o r y a c t i o n of c l o n i d i n e was a n t a g o n i z e d by the s~ecifi~ (~2-adrenergic a n t a g o n i s t ]~ohimbine (I0 -D, 10 -~ M). C l o n i d i n e (I 0 - 5 - I 0 - " M) s t i m u l a t e d the synaptic membrane (Na++K +)-ATPS~e activity suppressed b y F e C l 2 (5 x 1 0 M) i n t h e i n c u b a t i o n m e d i u m c o n t a i n i n g 10 -6 - 2.2 x 10 -7 M f r e e Ca 2+, a l t h o u g h clonidine failed to s t i m u l a t e the ( N a + + K + ) - A T P a s e a c t i v i t y in the a b s e n c e of F e C I 2. T h e s t i m u l a t o r y e f f e c t of clonidine was antagonized by yohimbine. Yohimbine alone had no effect on the enzyme activity. The c o n c e n t r a t i o n s of the s y n a p t i c membrane-bound Fe w a s 3.2 + 0.4 x 10 -6 m o l eq./g m e m b r a n e p r o t e i n in the a b s e n c e of added FeCI 2. These r e s u l t s i n d i c a t e that c l o n i d i n e may stimulate the s u p p r e s s e d (Na+ +~K+ ) -ATPa se activity by interacting with F e z+ a t e 2adrenoceptor sites and inhibit membrane d e p o l a r i z a t i o n a n d / o r r e l e a s e of NA t h r o u g h its stimulatory action on the (Na++K+)-ATPase a c t i v i t y in the rat c e r e b r a l cortex. Department of Pharmacology, Kagoshima U n i v e r s i t y Dental School, K a g o s h i m a 890, Japan.

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EFFECT OF METOPROLOL ON MYOCARDIAL BETA-ADRENERGIC RECEPTORS IN EXPERIMENTAL DOXORUBICIN-INDUCED CARDIOMYOPATHY IN RATS

PHARMACOLOGICAL CHARACTERISTICS OF VOMITING P R O D U C E D BY D O P A M I N E D. Jovanovi~-Mi6i6 ~R. Samard~i6 and D. B. Beleslin The role of dopamine receptors involved in the regulation of emesis in the area postrema has not been fully elucidated yet. Apparently~ early pharmacological studies suggested that neuroleptics affect emesis via central dopamine receptors. H o w e v e r ~ reports on dopamine-induced e m e s is as well as on the participation of dopamine receptors in this emesis are still scarce (D.Jovanovi6-Mi6is et al. Met.Brain Dis.,i,55~1989). Therefore~ the aim of the present experiments was to evaluate the emetic activity and to study the pharmacological properties of receptors in the area postrema involved in the emesis evoked by dopamine injected into the cerebral ventricles of unanaesthetized cats. Intracerebroventricalar (i.c.v.)injections of dopamine produced dose-dependent and shortlasting emesis~ which was abolished after ablation of the area postrema. The dopamine antagonist chlorpromazthe~ the alpha-adrenergic blocking agent yohimbine and the antihistamine chIoropyramine injected i.c.v, inhibited the emetic response of dopamine. Yohimbine and chloropyramine were m o r e potent antagonists than chlorpromazine. O n the other hand~ the ganglionic blocking agent m e c a m y l a m i n e ~ the antimuscarinic drug ~ atropine and the opiate antagonist~ naloxone had no effect on the emetic response of i.c.v, dopamine. These results suggest that alpha-adrenoceptors rather than dopamine receptors in the area postrema reflect the emetic response to dopamine. Supported by a grant from the Scientific Fund of the SR of Serbia~ Beograd~ Yugoslavia. Dept. of Pharmacology, Medical Faculty~P.O.Box 662~ ii000 Beograd~ Yugoslavia.

N. Fujita, M. Hiroe~ Y. Tsurumi, T. Toyosaki, Y. Ohota, M. Hasumi, T. Horie and S. Hosoda The effect of beta-blockade (Metoprolol; lOmg/kg B.W./ day s.c. via osmotic minipump) on myocardial betaadrenergic receptors (BAR) in doxorabicin (DOX)-induced cardiac damage was investigated. DOX was injected via the tail vein to rats at doses of 3mg/kg B.W./week for 5 weeks. One week after the final injection, rats were divided into two groups, M(with Metoprolol; n=9) and D (without Metoprolol; n=lO). After 3 weeks' infusion, plasma norepinephrine (p-NE) levels and BAR density ( 1-125 iodocyanopindolol binding on crude membranes) were measured. Left ventricular end-diastolic pressure (LVEDP) was also measured and the results were compared with those from a control group (C; n=6). In group D, decreased BAR density and increased p-NE levels were revealed, indicating the down -regulation. But in group M, the BAR density and p-NE levels were similar to those in the control. The LVEDP was increased in group D, but was normal in group M. BAR density(fmol/mg) p-NE (ng/ml) LVEDP (mmHg)

group C 62• 0.6• 6.0•

group D 44• 3.6• 13.4•

group M 55• 1.0• 8.4•

These results suggest That Metoprolol is a promising drug for treatment of DOX-induced cardiomyopathy. Department of Internal Medicine, The Heart Institute of Japan, Tokyo Women's Medical College, 8-i, Kawada-eho, Shinjuku-ku, Tokyo 162, Japan.

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ACTION OF DIHYDROERGOKRYPTINE(DEK) ON BLOODPRESSURE(BP) AND NOREPINEPHRINE(NE) RELEASE FROM NERVE ENDINGS IN HUMANS A.Palermo, F.Colombo, P.Bertalero, N.Borchini, A.Libretti and F.Mailland DEK is a hydrogenated ergot alkaloid with strong dopaminergic a c t i v i t y in CNS according to animal pharmacology and human studies. Our aim was to investigate the a c t i v i t y of DEK on cathecholamine release and systemic circulation in humans. The studies were performed on eighteen healthy male volunteers, according to a within/between subjects design : I) DEK (3-6 mg os) antagonism to tyramine (TYR:I-6 mg i v ) induced r i s e in BP and NE release : comparison with prazosin (PRZ:2 mg os) and placebo (PLC); 2) s u l p i r i d e (SULP:IO-IO0 mg im) antagonism to DEK (0.25 mg i v ) induced decrease of BP and plasma NE. BP was recorded sphygmomanometrically and NE and epinephrine (E) measured by HPLC method. Results : TYR caused an increase of both SPB (by 32%) and NE release (by 40%) that was unaffected by DEK while the pressor e f f e c t of TYR was p a r t i a l l y prevented by PRZ (SBP from 113.0 + S.D. 4.7 to 145.8 + 3.8 mmHg a f t e r TYR + PLC and from I I~.2 + 4.0 to 1 3 8 . 3 ~ 7.5 a f t e r TYR + PRZ; NE from 161.5 + 48.5 to 272.7 + 60.1 and from 170.7 + 52.7 to 313.3 ~ 8 8 Z , r e s p e c t i v e l y ) ? On the contrary, DEK-caused a decrease of BP and plasma NE that was dose-dependently prevented by SULP (NE 4]% decrease a f t e r DEK, 0.6% a f t e r SULP, 18% a f t e r I0 mg SULP+DEK, 0.6% a f t e r I00 mg SULP+DEK). I t is concluded that DEK is able to stimulate presynaptic DA2 receptors, while i t does not a f f e c t alphal receptors of vascular bed in humans.

ARE THE CENTRAL MUSCARINIC HETEROGENOUS ?

M-2

RECEPTORS

Institute ofCIinica Medica, "L.Sacco"Hospital, Milan

R. Samard~i6, K. Stefanovi6 -Deni6 and O.B. Beleslin The effect on behaviour of carbachol and the muscarinic ganglionic stimulant M c N - A - 3 4 3 injected into the cerebral ventricles (i.e.v.) of the cats w a s studied and compared. l.c.v, carbachol in smaller doses caused longlasting aggression without convulsions~ whereas large doses evoked convulsions preceded by shortlasting aggressive behaviour. I.c.v, M c N - A - 3 4 3 evoked only autonomic and motor effects. Only w h e n M c N - A - 3 4 3 was used in the largest doses~ inconsistent and shortlasting aggression of slight intensity w a s observed. The antimuscarinic drugs (atropine~scopolamine~ trihexyphenydyl ~ biperiden~homatropin~eucatropin and hexocyclium) ~ but not the ganglionic blocking agents and propanteline~ all injected i.c.v. , attenuated or blocked the aggressive behaviour induced by non-convulsant doses of i.c. v. carbachol. The largest doses of ganglionic blocking agents prolonged the duration of aggression indUced by carbachol. W h e n convulsant doses of carbachol w e r e injected i.c. v. ~ the antimuscarinic drugs in selected doses~ but not the ganglionic blocking agents~ prolonged the duration or had no effect on aggressive behaviour ~ and at the s a m e time inhibited convulsions. It is postulated that the aggressive behaviour and the convulsions of i.c.v, carbachol reflect rather the central muscarinic M - 2 than central muscarinic M - I mediation~ and that the central muscarinic M - 2 receptors at least functionally are not homogenous. Supported by the Scientific Fund of the SR of Serbia~Beograd~ Yugoslavia Department of Pharmacology, Medical Faculty ~P. O. Box 662, 11000 Beograd ~ Yugoslavia.

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MUSCARINIC AUTORECEPTOR INHIBITION OF ACH RELEASE FROM THE FROG SARTORIUS MUSCLE IN VITRO. M.S. Arenson Muscarinic autoreceptor induced inhibition of acetylcholine (ACh) release might limit the effectiveness of anticholinesterase treatment in Alzheimers disease, This report describes the results of some electrophysiological experiments using muscarinie ligands to investigate feedback inhibition on a simple frog muscle preparation. Fibres were impaled with microelectrodes and samples of mepps and epps were recorded before (control) and in the presence (test) of a muscarinic ligand. The amplitude quotient e ~ / ~ - p was used to calculate quantal content (M); mepp frequency (F) was the index of spontaneous release. Results, F or M, are expressed as a percentage change and compared with data from u~reated fibres. In Mg- -paralysed fibres (low ACt release) the agonists muscarine and oxotremorine (10-100 ~M) reduced M evoked at 0.33 or 20 Hz by up to 60% whereasno change (0.33 Hz) or a small increase (13%, 20 Hz) was recorded for the untreated group. The reduction in M evoked by oxotremorine was attenuated by atropine (100 nM). Oxotremorine (30 and i00 ~M) reduced F by 28 and 42% respectively but muscarlne was less effective. The oxotremorine evoked red~tion in F was prevented by atropine (I00 nM). In Mg- paralysed fibres atropine had no effect on M evoked at 0.33 or 20 Hz or on F. In giycerol~treated fibres (normal ACh release) atropine (i00 nM) increased F but did not affect M evoked at 0.33 Hz. At 20 Hz the mean M-value of the last iO of a train of 140 epps was 82 + 1.8% of that of the first epp. Atropine (100 and 300 nM) did not affect M of the first epp or the subsequent rundown. These data suggest that the frog muscle is a useful modal for studying muscarinic presynaptic inhibition. Department of Pharmacology, St. Bartholomew's Hospital Medical College, Charterhouse Square, London ECIM 6BQ, UK. Supported by the Joint. Research Board.

CHARACTERIZATION OF A SIGMARECEPTOR IN HUMAN LYMPHOCYTES BY BINDINGSTUDIES WITH 3H-DTG. t. Henriksson. A. Wahlstrbm, E. Weber* and A. Rane

The sigmareceptor has been shown to produce psychotemimetic e f f e c t s in humans, The aim o f t h i s study was to find out if the receptor w a s to be found on lymphocytes and characterize them. The human lymphacytes have been isolated From whole blood by passing over a density gradient (Fieall-Paque, Pharmacia). In some experiments the cells were stored at -70~ for no more than 5 days and then sonicated prior the binding assay. The binding assay was performed according to Weber et a] (1986), using guinea pig brain membranes. In brief, the lymphocytes or a sonicated fraction (protein cone 0.25-1.8 mg/ml) were incubated with 1.3-di(Z-[5-iH]tolyl) guanidine, (DTG) (cone. 1.7 nM) For 60 min at room temperature. The non-specific binding was defined in the presence of 10 uM DTG. The incubation was terminated by rapid filtration under vacuum through Whatman GF/B glassfiber filters using a Brandel 48-well cell harvester. The filters were washed twice and dissolved in aquasol and the radioactivity was measured by liquid scintillation spectrometry. The binding was specific and saturable. However, the n o n specific binding somewhat high probably attributed to contamination of other blood components. The lymphocytes may need further purification. Binding os various drugs to the 3H-DTG specific sigma-receptor showed the same rank order in lymphacytes as in guinea pig brain membranes. *Vollum Institute for Advanced Biomedical Research and Depts. Biochemistry and Psychiatry Oregon Health

Sciences U n i v e r s i t y , Portland, USA., Oiv. of Clinical Pharmacology, University Hospital, S-751 85 Uppsala, Sweden.

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PP 07.24 S T U O I E S ON THE P H A R M A C O K I N E T I C S AND P H A R M A C O D Y N A M I C S OF P R O P I V E R I N E BY A D D I T I O N A L USE OF A RADIORECEPTOR ASSAY K.-O. H a u s t e i n ~ G. HOller~ U. W i n k l a r and

H. K l a t t The p h a r m a c o k i n e t i c s of p r o p i v e r i n e (P; ~r phenyl-n-propoxy-l,2-acetic acid-4-(1-methyl-piperidinyl)ester), a novel a n t i s p a s m o d i c drug, was s t u d i e d in 12 h e a l t h y v o l u n t e e r s in cross over after i.v. i n j e c t i o n of 5 mg and oral intake of 15 mg. The } v a g o l y t i c c a p a c i t y ' of the p l a s m a s a m p l e s was m e a s u r e d by a r a d i o r e c e p t o r assay. The r e c e p t o r s were d e r i v e d from rat brain. P was e l i m i n a t e d from the p l a s m a with a halfli~e time of 4.1 h. W i t h i n 4 days, 87.5 (i.v.) or 53.5 % (per as) of the a d m i n i s t e r e d dose was e x c r e t e d in urine. P u n d e r g o e s an e x t e n s i v e deg r a d a t i o n by o x i d a t i o n of the t e r t i a r y n i t r o g e n in the p i p e r i d i n y l m o i e t y y i e l d i n g N - o x i d e s , o x i d a t i o n of one of the C - a t o m s of the p r e p i o n y l side chain, o x i d a t i o n of the N - m e t h y l group res u l t i n g in N - d e m e t h y l a t i o n p r o d u c t s , and ester c l e a v a g e . If c o m p a r e d by r a d i o r e c a p t o r assay, the d e s a l k y l - P (M2) p o s s e s s e s a 500 to l O 0 0 f o l d h i g h e r v a g o l y t i c a c t i v i t y than P, and it p o s s e s ses the same a c t i v i t y as s c o p o l a m i n e . The changes in s a l i v a t i o n , a c c o m o d a t i o n , p u p i l a r y size, and heart rate m e a s u r e d in the v o l u n t e e r s were c o m p a r e d w i t h the data of the r a d i o r e c s p t o r assay. B e c a u s e u n c h a n g e d P a p p e a r e d in p l a s m a and urine at about 6 to 8 % o f a d m i n i s t e r e d dose, the p h a r m a c o d y n a m i c e f f e c t s are c a u s e d by P and M2 due to drug l a t e n t i a t i o n . I n s t i t u t fur K l i n i s c h e P h a r m a k o l o g i e der Mediz i n i s c h a n A k a d e m i e Erfurt, N o r d h ~ u s e r S t r a g e 74, O O R - 5 0 1 0 Erfurt

PP 07.26 A CENTRAL ANTICHOLINESTERASE PHARMACOKINETICS

DRUG (MEPTYL-PHYSOSTIGMINE):

IN RATS AND HUMANS AFTER DIFFERENT DOSES

R. Urso, D. Cerri, A. Baldi, G. Se~re MF-201 (Mediolanum, Milan, Italy) is an anticholinesterase drug similar in structure to physosti~mine from which it differs for the presence of a chain of 7 carbon atoms. The pharmasokinetics of this drug was assessed in rats using an electrochemical HPLC method and in humans measuring plasma acetylcholinesterase activity. In rats the MF-201 kinetics was followed in plasma, kidney,liver, heart and brain after intramuscular (4 mg/kg) and oral (8 mg/kg) administration. The oral bioavailability was 28%, while the tissue to pl~ sma concentration ratios after the i.m. and p.o. doses w~ re: 4.4 and 6.7; 4.9 and 8; 3.1 and 23.6; 7.8 and 0.8 in heart, brain, liver and kidney, respectively.After i.m. ad ministration, drug plasma clearance and volume of distribu tion were computed: Cl = 1.42 L/h, Vd = 9 L.The plasma tar minal half-life was about 15 hours. After multiple oral doses ~n rats (8 mg/kg twice a day for 7 consecutive days) drug concentrations after the last dose were higher than after the first dose in plasma,kidney and liver while brain and heart concentrations did not increase. In humans the drug was administered orally (0.5; 0.25; 0.i; 0.0,6 mg/kg) to four groups of three subjects and the plasma kinetics was followed up to 96 hours after administration. The drug tar minal half-life was very long (above 5 days) and the mean plasma AUC during the time interval 0-24 hours were: 16.2+ 16; 44.4~12; 49.15~14; 66.3~16 for the four doses respecti rely in increasing order. Istituto di Farmacologia, Laboratorio di Farmacocinetica, Universit~ di Siena, Via Della Scotte 6, 53100 Siena, Italy

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AF-DX 116 - M2A-CHOLINOCEPTOR-SUBTYPESELECTIVITY (CARDIOSELECTIVITY)IN VITRO AND IN MAN

PRELIMINARY PHARMAKOKINETIC STUDIES ON GLYCOPYRROLATE J. Kanto, T. Ali-Melkkil~, T. Kaila, E. lisalo

* Schulte B, ** Pitschner W, * Volz C, *Horne C, *** Su C, ** Schlepper M, * Mutschler E, * Palm D The Mrcholinoceptor(NPchc)-antagonist AF-DX ll6 (ll-((2- (diethylamino) methyl )-l-piperidinyl )acetyl )-5,11-dihydro-6H-pyrido(2,3-b)(] ,4) benzodiazepine-6-one) has been shown to differentiate between 3 M-chc-subtypes. ~an Ki-values, determined in receptor binding studies: cardiac M~a-chc: 193 nM; glandular M2B-chc: 4.3 uM; M.- chc: 489 nM. To investig~Ife this selectivity in man, AF-DX ll6 effects on heart rate and salivary flow were measured, Effects were correlated to the in vitro occupancy of M~a- and M~-chcs as determined by a subtypeselective radioreceptorassa~/~(RRA) of~the #F-DX If6 amount in plasma, sampled in parallel to effect measurements. AF-DX ll6 concentrations were calculated from the RRA and detected by HPLC. Pharmaco- and effect-kinetics were compared after oral (240rag,n=7) and i .v. (38ng,n=8) administration of AF-DX ll6. - Both doses (24Cmg/35mg)were equieffective with respect to heart rate increase (mean max. effect:+24 bpm/+24.7 bpm), they did not decrease salivary flow, Time course of heart rate increase differed distinctly: After oral administration maximumeffects were reached after one hour and lasted for the next 8 hours. In contrast, after i .v. administration maximumeffects occured instantaneously, but disappeared within 6-8 hours, - In vitro M~a-chc-occupancycorrelated well with heart rate increase. No significant' M~-chc-occupancy was observed, which confinTed lack of effects on saliv6~ly flow in man. - The comparison of AF-DX 116 plasma concentrations calculated from M-chc occupancy and detected by HPLCafter both routes of administration gave no evidence for the occurrence of active metabolites, mean elimination tl/2 after i.v. drug a~inistratien was 182 min/208 min (RKaJHPLC). Thus, AF DX 116, at the doses given, differentiates in a absolute selective manner between M~a- and M2B-chc in man. M-chc-occupancy, obtained from a subtype select~ge RRA c~n help to predict AF-DX I16 effects in man. These effects are not due to active metabolites. Delayed and prolonged effect and concentration kinetics after oral drug administration are assuTedto be due to prolonged absorption time. *Dpts of Pharmacology, University of Frankfurt, FRG **KerckNoff Klinik der Max-Planck-Gesellschaft, Bad Nauheim, FRG ***Firma Thomae, Biberach, F~G

Up to now, there is almost no knowledge about the pharmacokinetics of glycopyrrolate, an anticholinergic drug used to treat various gastrointestinal disorders and in anaesthetic practice as well. A sensitive radioreceptor assay for the measurement of glycopyrrolate (lower limit of sensitivity = 100 pg/ml) was used to evaluate the basic kinetics of the drug. The intra- and interassay variation was within 10 %. Patients undergoing ophthalmological surgery were studied. Their age varied from 44 to 79 years.

-

Following an oral dose of glycopyrrolate (4mg, n = 6), an apparently low (a few per cents) and variable gastrointestinal absorption was found. On the contrary, an i.m. injection, 0.008 mg/kg, produced a fast and more predictable systemic drug absorption with a mean peak at 16 min (C = 15.8 + 10.7 ug/l, n = 9). After an i.v. injection 0.~ m g / k g ~ n = 6), glycopyrrolate was rapidly distributed with a half-life of 2.2 + 1.3 min. The half-life of the elimination phase was 0.8 + 0.2 h. The total body clearance was 0.54 + 0.14 i/kg/h~nd the distribution volume during the eTimination phase 0.64 ~ 0.29 i/kg. About half of the parent drug and/or metabolites binding to muscarinic receptors was excreted into the urine within the first 3 hours after the intramuscular dose (0 - I h : 33 + 10 %, I - 3 h : 16 + 5 %, 3 - 6 h : 8 + 4 %, 6 - 8--h = 3 + 2 9). No correlation between the pla--sma levels and different drug effects was observed (heart rate, blood pressure, antisialogogue effect). Departments of Clinical Pharmacology and knaesthesiology, University of Turku, SF-20520 TURKU, FINLAND

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BLOCKADE OFVAGALLY-INDUCEDBRADYCABDIABYCIMETIDINEAND

uI-ACID GLYCOPROTEIN AND DRUG BINDING IN CONTINUOUS AMBULATORY PERITONEAL DIALYSIS PATIENTS F.M. Belpaire, E_=.J. Van de Velde, N.H. Fraeyman~ M.G. Bogaert and N. Lameire~--*--"

~'ITIDIRE M,C. E. Gwee and L.S. Cheah The histamine H2-receptor antagonists cimetidine and ranitidine are w~dely used in the treatment of peptic ulcer disease and in hyperacidity states. The drugs also mediate some actions which appear to be unrelated to H 2receptor antagonism. Recently, experimentally large doses of cimetidine and ranitidine have been found to have actions at cholinergic sites in the autonomic ganglia, neuromuscular junction and the cholinesterase enzyme.

The effects of cimetidine and ranitidine on vagallyinduced bradycardia were studied. Dunkin-Hartley guineapigs of both sexes between 450 a n d 60Ogm were anaesthetised with a mixture of pentobarbitone sodium (15 mg/kg) and urethane (I g/kg)o Blood pressure and heart rate were continuously recorded on a Grass polygraph. Bradyeardia was induced by stimulating (6-15 Hz) either vagus nerve at 3 min intervals. When conditions were stable, intravenous infusion of either cimetidine (15 pmol/kg/min) or ranitidine (5 pmol/kg/min) was started. Both drugs progressively blocked the vagnlly-induced bradycardia during the infusion period; infusion was stopped at maximum blockade. The vagally-induced bradyeardia recovered spontaneously on stopping the infusion. Bradycardia induced by methacholine was similarly abolished by both clmetidine and ranitidine. Our results show that eimetidine and ranitidine can cause reversible blockade of cardiac muscarinic receptors. The clinical implications of our findings will be discussed. Department of Pharmacology, National Singapore, Kent Ridge, Singapore 0511 Supported by a grant (RP University of Singapore.

70/84)

from

University the

of

The influence of continuous ambulatory peritoneal dialysis (CAPD) in renal failure patients on concentrations and on concavaline A (Con A)-dependent microheterogeneity of ul-acid glycoprotein (AAG) in serum and dialysate, and on serum binding of oxprenolol, propranolol and phenytoin was studied. In the patients before CAPD (n = 8), as compared to healthy volunteers (n = 6), the serum binding of oxprenoioi and propranolol was higher and that'of phenytoin lower, and serum AAG concentrations were higher. During the first weeks after starting CAPD, the serum AAG concentrations rose, with a concommitant increase in the binding of oxprenolol and propranolol. Subsequently, AAG concentrations and binding of oxprenolol and propranolol decreased to the values found before starting CAPD. The binding of phenytoin showed little change. The glycan heterogeneity of AAG, expressed as a reactivity coefficient (ratio of the Con A-reactive AAG component to the Con A-non reactive AAG component) did not change significantly during CAPD treatment. AAG concentration in dialysate was 2 to 5 % of that in serum, and there was a good correlation between the reactivity coefficients in the dialysate and those in the corresponding sera. CAPD thus influenced serum drug binding transiently, due to a change in AAG serum concentration. Heymans Institute of Pharmacology and Department of Nephrology*, University of Gent Medical School, Gent, Belgium.

National

PP 07.29

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PLASMA-PROTEIN BINDING OF DIAZEPAM, FLUNITRAZEPAM AND ITS MAIN METABOLITES IN CRITICAL CARE PATIENTS INFLUENCED BY PARENTERAL NUTRITION USING FAT EMULSIONS Heinemeyer G., *Ebersp~cher U., ~Papadopoulos G., WStriebel H.W., "Link J. and *Roots I: Beratungsstelle f o r Vergiftungserscheinungen, Pulsstra6e 3-7, 1000 Berlin 19, * I n s t i t u t fQr Klinische Pharmakologie and ~Ktinik fQr An~sthesiologie und operative Intensivmedizin, Klinikum Steglitz, 1000 Berlin 45

POSSIBLE IMPLICATIONS OF PROTEIN BINDING DISSOCIATION RATE CONSTANTS ON THE H A L F - L I F E OF HIGHLY PROTEIN BOUND DRUGS (e.g. OLSALAZINE) N - O Ahnfelt, LI. Elding and M. Ryde The protein binding kinetics to human serum albumin and the elimination pharmacokinetics were compared for olsalazine, a new drug intended for the treatment of ulcerative colitis, the metabolite olsalazine-O-sulfate and warfarin. These compounds are all bound to more than 99% to human serum albumin and the volume of distribution after i.v. administration, was found to be low, viz. olsalazine = 5.7 1 and warfarin = 7.61 (O'Reilly et al, Thromb. et Diath. Haemorrh. 25, 178, 1971). In spite of this, olsalazine was cleared rapidly (tv2 = 0.9 h), via the liver and kidneys in about equal parts, possibly due to higher dissociation rate constant, k2,1 = 28 s -1.

Introduction: Free f a t t y acids (FFA) are well known modif i e r s of plasma protein binding of highly bound drugs such as benzodiazepines, given f r e q u e n t l y in critical care patients f o r sedation. FFA concentrations increase greatly in those patients when receiving high caloric parenteral nutrition. Plasma free levels (fu) of diazepam (0), desmethyldiazepam (DD) and flunitrazepam (F) were t h e r e f o r e studied in 9 operative intensive care patients receiving parenteral n u t r i t i o n with fat emulsions. All determinations were performed gaschromatographically. Results: FFA concentrations (C16:0-61B:2) during fat i n f u sions measured o v e r a period of 24 hours increased from basic values of 0.5-0.9 up to maximal levels of 6.1 mmol/I. D and DD free concentrations also varied o v e r a great range o f 40 up to 300 ng/ml, due to an increase in the free f r a c tion of 2 to ~20%. Excellent correlation with FFA concentrations as calculated f o r all values measured was found f o r 0(r=0.91) and DD-(r=84) fu (pO.05). In all cases changes in fu o c c u r red within 3 hours. Discussion: Modulation of benzodiazepine free concentration that is responsible f o r pharmacological efficacy can be explained by variations in free f a t t y acid concentrations. Extensive changes in its levels must be expected when fat emulsions are given. Sedative effects of benzodiazepines can t h e r e f o r e varied in such situations. The difference between Diazepam and Flunitrazepam shows that less bound drugs should be p r e f e r r e d in this extreme clinical situation.

D + P

kl ~ k- 1

DP'

k2 ~_~ k- 2

DP

k2,1 = k_2 * k_l/(k_l + k2.)

In contrast, olsalazine-O-sulfate (tv2 ~ 170 h) and warfarin (tv2 = 31 h, see ref. above) both exhibit relatively low dissociation rate constants, k2,1 = 1.1 and 3.0 s -1 (N. Rietbrock et'al, Arch. PharmacoL 313, 269, 1980), respectively which correlates to the long half-life. They also exhibit a stronger shift in the second conformafional relaxation step, K'2(= k2/k..2): 2.7 and 15, respectively as compared with 0.62 for olsalazine. This might also contribute to the difference in elimination rate. In conclusion this study shows that a detailed analysis of both the extent of protein binding and the dissociation rate constants might explain differences seen in the pharmacokinetics for similar compounds. Dept. of Bioanalysis and Kinetics, Pharmacia LEO Therapeutics AB, S-751 82 Uppsala, Sweden.

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PP 07.32 T H E B I N D I N G OF D - P R O P R A N O L O L PROTEINS

TO C E R V I C O - V A G I N A L MUCUS"

A QUANTITATIVE PHARMACO EEG S ~ Y ON WEB 1881 Y. OKAJIFi~, T.KINOSHITA, A.SAITO, K.NOBUHARA, T.YAGYU, N.SAITO, K.HATASHITA, Y.HATASHITA and M.SAITO

I.G. Salas, R.M Pearson, P. Turner Propranolol is a basic (pka 9.5) and lipid soluble drug, which is extensively bound (92-97%) to serum protein, mainly alpha-l-acid glycoprotein. D-propranolol 80mg given by mouth to 6 healthy female volunteers achieved concentrations in cervicQ-vaginal mucus greatly exceeding those in plasma at 12 and 24 hours (Pearson, R.M et al. Lancet 2, 1480, 1980). It is important to determine if its concentration in c.v. mucus could be explained by binding to proteins. Twenty healthy female volunteers, aged 18- 35 years, (ten of them drug free, ten on oral contraceptives) were asked to attend on day 12 of their menstrual cycle. Samples of c.v. mucus were taken by them in privacy. The sample was transferred to a pre-weighed vial and was re-weighed afterwards. Cervico~vaginal mucus was diluted in an equal weight of phosphate buffered saline. Aliquots (i00 ul) of c.v mucus were dialysed against the same volume of phosphate buffered saline (pH=7.36). CI~ D-propranolol was added to phosphate buffered saline in a concentration of 460 ng/ml. Dialysis was performed at 37 ~ for 3 hours. The Mean ~ Sem percentage binding of D-propranolol to c.v.- mucus proteins in drug free female volunteers was 25.8% + 2.6 and those on OC was 30.0% ~ 1.9. No significant difference was found between the groups (Two sample T test). The secretion of D-propranolol into c. v. mucus could not be explained by binding to proteins OC does not influence D-propranolol cervico-vaginal protein binding. St. Bartholomew's Hospital, Clinical Pharmacology Dpt., West Smithfield, London ECIA 7BE, U.K.

PP 07.33 T H E I N F L U E N C E O F P L A S M A P R O T E I N B I N D I N G ON T H E P E N E T R A T I O N OF O R A L A N T I F U N G A L A G E N T S I N T O S K I N BLISTER FLUID M. S c h ~ f e r - K o r t i n q , H.C. K o r t i n q a n d A. L u k a c s I m p e d e d t r a n s f e r of antibacterial drugs from p l a s m a to t i s s u e s b y s t r o n g p l a s m a p r o t e i n b i n ding has been discussed repeatedly. Since many oral a n t i f u n g a l a g e n t s are bound extensively (e.g. ketoconazole, 98-99%; itraconazole, 99.8%), t h e i m p a c t o n d r u g l e v e l s at t h e t a r g e t tissue has to be evaluated. With respect to d e r m a t o p h y t o s i s of g l a b r o u s skin, a c c e s s is obtained by the skin blistering techniques. 18 h e a l t h y v o l u n t e e r s r e c e i v e d s i n g l e d o s e s of g r i s e o f u l v i n (330 mg), k e t o c o n a z o l e o r i t r a c o n a z o l e (200 mg). T h e n t h e y ingested the drugs o n c e d a i l y for 5-10 days. F o l l o w i n g t h e u l t i m a t e doses, s t e a d y s t a t e s h o u l d h a v e b e e e n o b t a i ned. T o t a l d r u g l e v e l s in plasma, s u c t i o n b l i s t e r f l u i d (SBF) a n d c a n t h a r i d e s blister fluid (CBF) w e r e d e t e r m i n e d f o l l o w i n g t h e s i n g l e and t h e u l t i m a t e dose. F r e e d r u g l e v e l s w e r e c a l c u lated taking protein binding in t h e s e fluids into a c c o u n t . F o l l o w i n g t h e u l t i m a t e dose, t h e c o n c e n t r a t i o n s of f r e e g r i s e o f u l v i n a n d k e t o c o n a z o l e in b o t h b l i s t e r f l u i d s w e r e c l o s e t o free drug levels in p l a s m a . T h u s distribution equilibrium was obtained. Itraconazole concentrations in b o t h b l i s t e r fluids, h o w e v e r , w e r e l o w e r t h a n e x p e c ted. T r o u g h l e v e l s of u n b o u n d itraconazole in SBF and CBF were 0.239• and 0.334• n g / m l (serum l e v e l s 0 . 4 2 2 • ng/ml; p ~ 0 . 0 5 ) . Thus plasma protein binding exceeding 99% m a y delay drug distribution considerably. P h a r m a k o l o g . I n s t i t u t f. Naturwissenschaftler, Universitat Frankfurt, Theodor-Stern-Kai 7, D - 6 0 0 0 F r a n k f u r t / M . , FRG

Rapid increase of senile population is now bec(mting socially as well as medically the most important problem in Japan. From the clinical view point, it is an unsolved problem whether any anti-dementia substance exist or not. Recently various nootropio drugs have been developed, but we knew that they were not the anti-dementia agent in a narrow sense. Boehringer Ingelheim has developed WEB 1881, whose chemical structure is close to those of piracetam, oxiracetam and aniracetam, which are known as nootropic agents. In order to determine clinical effects of W ~ 1881 as objectively aspossible, we havecarried out a quantitative pharmaco EEG study in patients group. Six patients with senile dementia of Alzheimer type (SDAT) have been chosen for this study. Their ages ranged from 68 to 85 years and the severity of dementia ranged from slight to moderate. The oral administration of WEB 1881 was continued for twelve weeks, the daily dosage was started at 400mgper day and it was increased every four weeks at doctors choice up to 120Omg per day. EEG were recorded beforeand after every four weeks and examined with our analysis system. As the results, WEB 1881 produced a decrease of slow activity in EEG after the first four weeks, a decrease of slew activity associated with an increase of alpha waves and fast activities after eight weeks and an increase of alpha waves and a decrease of fast activity after twelve weeks particularly in frontal to central area of the brain. The EEG changes induced by WEB 1881 can be classified as the vigilance enhancer type, which are shown by the noctropic agents. The F~G changes have been imaged by EEG mapping system and examined with the reference to the changes of serLml concentration of WEB 1881 as well as clinical symptomatologies. Kansai Medical University, Moriguchi-shi Osaka 570 JAPAN

PP 08.02 EFFECT OF AGE UPON STEADY-STATE SORBITOL CLEARANCE

J. Zeeh~ J.L.C. Dall, A.C.A. Glen, and D. Platt~ A l t e r a t i o n s in l i v e r perfusion occur for various reasons and may i n t e r f e r e with the elimination of various endoand xenobiotics~ S t e a d y - s t a t e e x t r a r e n a l s o r b i t o l c l e a r ance (S-Clss) was shown to be a measure of parenchymal l i v e r plasma flow(I) . Age changes of S-Clss were studied in 54 p a t i e n t s (29 female, 25 male; age range 68-95 y). They had been admitted f o r stroke r e h a b i l i t a t i o n (n=19), poor mobil i t y / f r a i l t y (n=14), ischaemic heart disease (n=6), Parkinson's (n=5), others (n=9). None of them was acutely i l l . Liver disease and decompensated cardiac failure were excluded by appropriate examinations. In the supine and fasted subjects sorbitol (S) was infused i.v (50 mg/min). Steady state plasma S concentrations from 150-180 min and urine S output were measured ensymatically. S-Clss was calculated as infusion rate divided by steady state plasma S concentration, corrected for renal Cl, and expressed as ml/min. Data were analyzed together with S-C1 va]ues obtained by the same technique in 32 subjects (1) . There was a fall in S-Clss with age: after stratification into age groups of <45y (n=14), 46-70y (13), 71-75y (13), 76-80y (17), 81-85y (17), and >85y (12) mean S-Clss were 723• 760• 635• 622• 540• and 474• ml/min, respectively. Spearman's rank correlation coefficient was rs=-0.94. No correlation was found between age and SClss per body weight (ml/min*kg). It is concluded that sorbitol clearance as a measure of liver perfusion decreases with age. The fall approximates 35% if the oldest and the youngest group are compared. Considerable interindividual variation renders predictions of S-Clss from age imprecise. The sorbitol method as a noninvasive technique may be used to assess liver perfusion in the elderly. (1)Zeeh et al., GASTROENTEROLOGY 95, 749-59 (1988) Victoria Geriatric Unit, Glasgow, UK and r ffir Gerontologie, Universit~t Erlangen, 8500 Nfirnberg, FRG

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PHARMACOKINETICS OF TIAPROFENIC ACID IN ELDERLY PATIENTS H.Eicher, D , H i l g e r t , D . P l a t t , W.Rieck, The pharmacokinetics o f t i a p r o f e n i c acid (T) and i t s influence on the e l e c t r o l y t e balance was studied on a group o f 20 g e r i a t r i c

SINGLE DOSE PHARMACOKINETICS OF SODIUM FLUORIDE IN THE ELDERLY P. Netter, F. Lapicque, C. Jeandel, B. Bannwarth C. Monot, P. Fener, F. Penin, G. Cuny, R.J. Royer

p a t i e n t s b e t w e e n t h e a g e s of 70 a n d 84 years. E a c h of t h e s e p a t i e n t s s u f f e r e d f r o m cardiac insufficiency w i t h o u t the c l i n i c a l s i g n s of deeompensation. T w a s g i v e n at a d o s a g e of 300 mg t w i c e a d a y f o r s e v e n days. On the first and t h e last d a y a s i n g l e oral dose pharmacokinetic study was performed. Serum l e v e l s w e r e determinated by HPLC. T h e f o l l o w ing p h a r m a c o k i n e t i c parameters were calculated u s i n g a m o d e l - i n d e p e n d e n t kinetic:

AUC0-| 119.9 ~ 5 4 . 7 ; C l t o t 50.5 • t~ 3.1 ~ 0 , 8 ; MTT 3 . 9 9 • V=s 1 1 . 3 • NO a c c u m u l a t i o n c o u l d be f o u n d during the seven days o f t h e r a p y . B l o o d p r e s s u r e , bo d yw e i g h t , edema, serum l e v e l s o f Na+ and K+ and 25 laboratory values showed no relevant c hange. No c o r r e l a t i o n was f o u n d between c r e a t i n i n e clearance and t i a p r o f e n i c acid clearance. The r e s u l t s o f t h i s study i n d i c a t e t h a t T is save in the treatment o f geriatric p a t i e n t s w i t h o u t accumulating or interfering w i t h t h e e l e c t r o l y t e and w a t e r b a l a n c e ,

Sodium fluoride (NAY) is used in the treatment of axial osteeporosis so that it is mostly given to elderly patients. The aim of this study was to compare pharmacokinetics of NaY in 12 elderly in-patients (aged 65 to 75) and 12 young healthy volunteers (aged 21 to 28). Each subject was given an enteric-coated tablet containing 50 mg NaY. Blood samples were drawn before dosing and 0.5 to 48 h thereafter. Urines were collected the day before and the 2 following days. Serum and urine fluoride was assayed with an ionselective Orion electrode. The pharmacokinetie parameters were calculated by interpolation through third degree Lagrange polynomials and monoexponential extrapolation. The Mann Whitney test was used for statistical analysis.

Tmax ranges (h)

Cmax (~g/1) Half-life (h) AUC (h) M

RT0-48 0-48 (h)

Vss/F (1)

young subjects 1.6 - 4.0

elderly 0.7 - 7.8

420 ! 95

651 ~ 398

0.235

6.5 + 1.4 2011 ! 313

9.9 + 5.1 3474 • 1821

0.046 0.085

10.3 -+ 4.1

0.184

99 + 18

128 + 162

0.387

8.5 + 2.9

8.4 + 3.0

0.712

8.5 -+ 1.4

p l.O00

I n s t i t u t f Q r Gerontologie d e r U n i v e r s i t a t Erlangen-NOrnberg, Heimerichstr.58,

48h Urine F-(mg)

D-8500 NQrnber9 9 0 , B u n d e s r e p u b i l k

A great inter-subject variability was observed specially in the elderly. Nevertheless the elimination half-life and the bioavailability as determined by AUC seem to be increased in old subjects.

Deutschland

D~partement de Pharmacologie Clinique, URA CNRS 1288 et Clinique M~dioale B, 84805 Vandoeuvre les Nancy (France)

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INCREASED RENAL TUBULAR CELL EXCRETION BY PATIENTS RECEIVING CHRONIC THERAPY WITH GOLD AND NONSTEROIDAL ANTI-INFLAMMATORY DRUGS M. M. R e i d e n b e r q , S. A. P a g e t a n d C. J. G a n l e y Using rheumatoid arthritis patients receiving gold as a model, we evaluated the renal effects of the chronic administration of very low doses of a nephrotoxic drug. The heavy metal, gold, has been shown to increase u r i n a r y e n z y m e e x c r e t i o n w h e n g i v e n in u s u a l doses to treat rheumatoid arthritis (Clin. Pharmacol. Ther. 28, 216, 1980). It is n o t clear whether chronic drug therapy, capable of raising urine enzyme excretion, represents i n j u r y to t h e k i d n e y o r m e r e l y d r u g effect. Urinary N-acetyl-~-glucosaminidase (NAG) and renal tubular cell excretion rates were measured in 19 patients receiving chronic treatment with gold and nonsteroidal antiinflammatory drugs (NSAID) for rheumatoid arthritis, i0 patients receiving NSAID's alone, and 8 healthy controls. None had evidence of kidney disease. The NAG was e l e v a t e d in t h e g o l d t r e a t e d g r o u p as b e f o r e . Median cell excretion rates (range) w e r e 72 (33 190) cells/mg urine creatinine in controls, 82 (0 - 370) in t h e N S A I D - t r e a t e d , a n d 330 (280 - 500) in t h e g o l d a n d N S A I D treated patients (p < 0.05 c o m p a r e d t o o t h e r two groups). This shows that there was i n c r e a s e d r e n a l t u b u l a r c e l l t u r n o v e r in t h i s group, suggesting low level renal tubular i n j u r y a n d n o t m e r e l y d r u g e f f e c t at t h e u s u a l d o s e of gold. Departments of Pharmacology and Medicine, Cornell University Medical College, 1300 York A v e n u e , N e w York, N Y 10021

THERAPY OF AGE RELATED CERE6RAL INSUFFICIENCY WITH ClTIDINE DIPHOSPHOCOLINE R. Eberhardt, G.-E. KUhne, I . Derr C it id in e Diphosphocholine (CDP-choline) probably acts through pharmacological compensation f o r the presumed deficiency of phospholipids and neurotransmitter metabolism, which are important in the development of age related brain function disordes. This placebo controlled double-blind cross-over study was performed to assess the effectiveness of CDP-choline in g e r i a t r i c patients with cerebral i n s u f f i c i e n c y , i . e . dementia of d i f f e r e n t e t io lo g y. A f t e r an i n i t i a l wash-out period of two weeks the patients received according to randomized order e i t h e r CDP-choline or placebo f o r 5 weeks; a f t e r a second washout period of f u r t h e r two weeks the patients received the a l t e r n a t i v e drug f o r additional 5 weeks. 6 psychometric and c l i n i c a l tests (Nuremberg G e r i a t r i c Inventory, SCAG) were performed at the end of each medication period with CDP-choline or placebo treatment. The s t a t i s t i c a l evaluation of a ll tests revealed: CDP-choline as f i r s t treatment improved s i g n i f i c a n t l y the results of a ll 6 tests compared to baseline whereas placebo as f i r s t treatment leads to a s i g n i f i c a n t improvement of the results in 4 of the 6 t e s t s . The f u r t h e r improvement during the 2nd cross-over phase in comparison to the I s t phase was more d i s t i n c t and s i g n i f i c a n t l y better during CDP-choline administration f o r a ll 6 tests whereas placebo did not show f u r t h e r s t a t i s t i c a l l y s i g n i f i c a n t improvement f o r any t e s t . These results indicate that the status of disease was improved during both cross-over phases by CDP-choline only. PHARMALOG I n s t i t u t e f o r Clinical Research, Frauenlobstrasse 28, D-8000 MUnchen 2 / FRG

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PHARMACOKINETICS OF LAMOTRIGINE, A NOVEL ANTICONVULSANT IN YOUNG AND ELDERLY. J. Posner, P. Creme and B. Weatherley. Clearance of drugs by conjugation is not generally considered to be greatly affected by ageing. Lamotrigine (3,5-diamino-6-(2,3-dichlorphenyl)-l,2,4-triazine), a new anticonvulsant, is cleared mainly by N-glucuronidation with subsequent excretion in urine. We have compared the pharmacokineties of lamotrigine in 2 groups of 12 healthy non-smoking volunteers: 5 men and 7 women aged 65-76 (mean 71) and 8 men and 4 women aged 26 - 36 (mean 31) years. Each subject received a single oral dose of 150 mg lamotrigine after an overnight fast. Blood was sampled at intervals and urine collected continuously for 168 h. Plasma and urine were assayed by h.p.l.e, and individual plasma data were fitted to a one-compartment open model using NONLIN. Mean (SD) kinetic variables are given in Table I. Table I

ABSOLUTE AVAILABILITY OF THE ANTIDEPRESSANT T I A N E P T I N E IN T H E E L D E R L Y : P R E L I M I N A R Y R E S U L T S I N 11 S U B J E C T S

Young Elderly Cmax #g.ml "I 1.67 (0.31) 2.06 (0.26) Tmax h 1.46 (0.99) 1.44 (1.24) AUC #g.mlfl.h 60.5 (24.5) 93.9 (20.2) 1.17 (0.II) 1.07 (0.i0) Vd/f l.kg "i i CL/f ml.min- .kg 0.66 (0.28) 0.42 (0.07) tl/2 h 24.3 (i0.i) 30.0 (5.5) CL R ml.min -I 2.57 (0.51) 2.45 (0.51) ~ose recovered 68 (7) 65 (6) excreted free 9.65 (4.7) 14.6 (3.7) The higher mean Cmax and AUC are largely attributable to the substantially smaller CL/f in the elderly. Recovery of drug was unaffected, therefore the difference in plasma clearance is probably attributable to diminished N-glucuronidation of lamotrigine in the elderly. Human Pharmacology Unit, Wellcome Research Labs. Beckenham and Orpington Hospital, Orpington, Kent, UK.

D. Carlhant *, J. Le Garree *, Y. Guedes *, C. Riehd *, C. Salvadori** and D. Mottier *** The absolute availability of tianeptine and the pharmaeokinetics of its major MC5 and MC3 metabolites were evaluated in 11 elderly volunteers (mean age 78.8 • 4.7 years - range 73-86} after oral and intravenous doses of 12.5 m g of tianeptine sodium salt given in random order and separated by 2 weeks. Plasma samples and urines were collected over 48 and 72 h periods respectively. Tianeptine and metabolites plasma and u r i n e c o n c e n t r a t i o n s were assessed u s i n g a n H P L C p r o c e d u r e . Pharmaeokinetie medelling was performed using SIPHAR program. T i a n e p t i n e w a s a b s o r b e d r a t h e r r a p i d l y ( t m a x 1.8 • 0 . 6 h , Cmax 246 5:55 ng.ml-1) and very efficiently (F = 0.79 +- 0.13 - 0.59-0.99) The mean residence time was 5.24 -+ 2.05 and 3.00 • 0.65 hrs after oral and i.v. administration respectively ; the mean time of absorption was 2.23 + 1.94h. After i.v. administration, following a limited distribution in the tissues (Vd ss = 0.41 • 0.08 1.kg-1) t i a n e p t i n e was r a p i d l y e l i m i n a t e d (t~tz = 3.14 • 1 . 1 6 h ) m a i n l y t h r o u g h biotransformation (CIR < 1 ml.min-1 -C1w = 128.5 _27.2 ml.min-l). The main plasma metabolite (MCs) appeared 0.18 - 0.04 h following the b e g i n n i n g of t h e i.v. a d m i n i s t r a t i o n (tmax 2.8• 1.0 h, Cmax 88 • 25 ng.ml-1). MC s metabolite was excreted mainly via further metabolism, with a terminal half-life of 10.8 -+ 7.3 h. After oral route, the kinetics of the MC5 metabolite remained unchanged except the tmax which was delayed (tmax : 3.7 • 0.6 h). The study showed that tianeptlne's absolute availability was good in elderly subjects. Furthermore, the administration was well tolerated, no alteration in ECG was observed even after i.v. dose. * ** ***

Laboratoire de Pharmacologic, H6pital Morvan, 5 avenue Foeh, 29285 BREST, France I.R.I.S., 27 rue du Pont, 92200 NEUILLY sur SEINE, France Service S6bileau, Hbpital Morvan, 5 avenue Foch, 29285 BREST, France

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CLINICAL PHARMACOLOGY OF PROCHLORPEEAZINE IN HEALTHY ELDERLY FEMALE VOLUNTEERS A.O. Isah, D.N. Bateman and M.D. Rawlins Proehlorperazine (PCZ), a piperazine phenothiazine derivative, is widely used in the symptomatic control of nausea, vomiting and vestibular disorders. Information on its kinetic and pharmaeodynamie profile in the elderly is limited. Methods: Six elderly female volunteers (mean age 69.3 + 2.3 years) were studied, receiving 3 treatments at least 7 days apart, viz. i. I.V. 3.125mg PCZ + placebo capsules (P)2. Oral 25mg PCZ + I.V. saline (S) 3.P + S in random order. The study was double blind and of cross-over design. Blood was sampled at intervals for determination of plasma PCZ, N-desmethyl PCZ (NDPCZ) by HPLC - ECD and prolactin (PRL) levels (EIA). Pulse, BP, salivary flow, choice reaction time (CRT), critical flicker fusion frequency (CFF) and subjective sedation, restlessness and dryness of mouth using visual analogue scale (VAS) were assessed at intervals. Results: Following l.V. PCZ the mean apparent volume of distribution was 14.9 ~ 1.81/kg, total body clearance CL= 1.7 + 0.31/kg and elimination half-life t89 = 7.5 + 1.8 h. PCZ was poorly absorbed after oral dosing Cmax 1.8 + 0.6ng/ml at (Tmax) 4.0 • 0.7 h with a mean bioavailability of 14.7 J 1.5%. NDPCZ levels were detected only after oral administration in 4 subjects Cmax 1.47 + 0.4ng/ml at 4 h. PEL rise peaked at 2 h after I.V. and at 6 h following the oral dose. Other pharmacodynamic measures were not significantly affected. No side effects were reported. Conclusion: The kinetic profile of PCZ is outlined. The elderly tolerated the PCZ dose administered, however, the low oral bioavailability may hav~ important therapeutic implications. Wolfson Unit of Clinical Pharmacology, The University of Newcastle upon Tyne, NEI 7EU, England.

AGING DOES NOT INFLUENCE THE ELECTROPHYSIOLOGIC AND HEMODYNAMICRESPONSES TO VERAPAMILIN ISOLATEDRAT HEARTS. O. Schmidlin and J.B. Schwartz Verapamil(V) has been reported to cause greater PR interval increases in young vs. geriatric patients, whereas the sinus node appeared more sensitive to V in the elderly. No data on potential age differences of hemodynamie parameters in response to V is available. To study the age effects of V on sinus node, atrioventricular conduction (AVC), and heart work independent of autonomic input we compared young adult (5me, n=8) with old (24mo, n=8) Fischer 344 rats in an isolated retrogradely perfused nonejeering Langendorff model. Spontaneous heart rate (HR), PR interval, AV block cycle length (AVBCL), mean dP/dt, and rate pressure product (RPP: HR*left ventricular systolic pressure) were recorded at baseline and after V (10, 20, 50, 100 ng/ml). Results: HR, PR interval, and AVBCL differed significantly at baseline but changes caused by V (regression analysis of dose vs effect data) did not differ between groups. Spontaneous AV or SA block, respectively occurred in 5/8 old vs 1/8 young rats at 100 ng/ml, p=ns. Mean dP/dt and RPP differed neither at baseline nor after peffusion with V. A ~e "Baseline p $10ne p , HR young 218+_5.5 <05 - 1.05-+18 ns (bpm~ old 179_+7.3 -1.03+-15 PRinterval yamg 43.0+1.9 <05 t .22:t08 ns L~_) old 62.1 _*4.3 .30• AVB(Z, young 119-+1.8 <05 2.21+_57 ns (ms) old 152+_5.5 $.18• dP/dt young 2.7,3+_.16 ns ] -.018~04 ns (mmH~Jms) dd 237+_16 -,021 +-003 RPP young 23824:038 ns -140+_20A ns (b~m*mm,H~) old 18991-_1031 -144+,24,1 l~ults are givenas ~+_~ L

F I I

Conclusions: AVC increases and HR decreases with increasing age, however no changes in hemodynamics were observed. The effects of V on electrophysiologic and hemodynamic parameters of the isolated heart are comparable in young adult and senescent rats. University of California , San Francisco, CA 94143-0446, USA

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S E R U M L E V E L A N D H A L F L I F E OF N I F E D I P I N E GERIATRIC PATIENTS

IN

R.B~cker,RzPeter,[email protected],D.Platt ~ S e r u m c o n c e n t r a t i o n s of n i f e d i p i n e w e r e m e a s u r e d in g e r i a t r i c p a t i e n t s d u r i n g t h e i r h o s p i t a l s t a y at the f i r s t d a y of a n a n t i h y p e r t e n s i v e t h e r a p y . 14 g e r i a t r i c p a t i e n t s p a r t i c i p a t e d in the s t u d y a f t e r t h e y h a v e g i v e n t h e i r w r i t t e n c o n s e n t (8 m a l e s w i t h a m e a n age of 7 7 . 5 y e a r s and a m e a n w e i g h t of 76kg, 6 f e m a l e s w i t h a m e a n age of 81.3 y e a r s and a m e a n w e i g h t of 66.8kg). N i f e d i p i n e t a b l e t s (IOmg) w e r e g i v e n b e f o r e b r e a k f e s t a f t e r a n o v e r n i g h t fast. B l o o d s a m p l e s w e r e d r a w n b e f o r e (blank) and a t v a r i o u s time i n t e r v a l s (up to 10 hours) a f t e r the a p p l i c a t i o n of the drug. The b l o o d s a m p l e s w e r e d e v e l o p e d for the a n a l y s i s und e r the e x c l u s i o n of light. S o d i u m c a r b o n a t e w a s a d d e d to the p l a s m a and then the s a m p l e s w e r e e x t r a c t e d w i t h d i c h l o r m e t h a n e - h e x a n e (8:1). The o r g a n i c l a y e r s w e r e e v a p o r a t e d u n d e r n i t r o g e n and the r e s i d u e s d i s s o l v e d in the s t a r t i n g e l u e n t of the g r a d i e n t h i g h p e r f o r m a n c e l i q u i d c h r o m a t e g r a p h y . T h e a n a l y s e s w e r e run o n C18 r e v e r s e d p h a s e c o l u m n s (30% a c e t o n i t r i l e to 8~% a c e t o n J t r i l e in 0.5% p h o s p h o r i c a c i d d u r i n g 6 m i n u t e s w i t h a f l o w r a t e of 1.4 m l / m i n ) . The e l u e n t w a s m o n i t o r e d s i m u l t a n e o u s l y at 234 and 350 nm. T h e d e t e c t i o n l i m i t w a s 2.5 ng/ml. T r a c e a m o u n t s of n i f e d i p i n e w e r e seen 5 m i n u t e s a f t e r the i n t a k e of the drug. C m a x was r e a c h e d a f t e r 40 m i n u t e s ( 1 0 5 n g / m l ) . T h e e l i m i n a t i o n h a l f l i f e t I/2~ w a s 165 m i n u t e s .

P H A R M A C O K I N E T I C S OF T R I A M T E R E N E IN G E R I A T R I C P A T I E N T S - I N F L U E N C E OF P I R E T A N I D E AND HYDROCHLOROTHIAZIDE W. Mdhlberg, H. Spahn, D. Flatt, and E. M u t s c h l e r . P h a r m a c o k i n e t i c s of t r i a m t e r e n e (single oral dose of 50 mg) and its p h a r m a c o l o g i c a l l y active m e t a b o l i t e ( O H - T A - e s t e r ) were d e t e r m i n e d in 20 g e r i a t r i c p a t i e n t s with m u l t i p l e diseases. Mean peak c o n c e n t r a t i o n of t r i a m t e r e n e was i n c r e a s e d in the e l d e r l y p a t i e n t s c o m p a r e d with the data of young healthy v o l u n t e e r s . C o a d m i n i s t r a t i o n of p i r e t a n i d e seems to lower the mean plasma c o n c e n t r a t i o n (AUC) and the mean c o n c e n t r a t i o n after 24 h of t r i a m t e r e n e as c o m p a r e d with coadm i n i s t r a t i o n of h y d r o c h l o r o t h i a z i d e . With inc r e a s i n g age, g l o m e r u l a r f i l t r a t i o n rate (GFR), renal plasma flow, and tubular e x c r e t o r y c a p a city are reduced. GFR is also i m p a i r e d after a d m i n i s t r a t i o n of thiazides. As c o m p a r e d with h y d r o c h l o r o t h i a z i d e , the c o a d m i n i s t r a t i o n of p i r e t a n i d e does not impair the GFR and is still e f f e c t i v e in reduced renal f u n c t i o n - w h i c h may e x p l a i n the results of our study. L e h r s t u h l Innere M e d i z i n / G e r o n t o l o g i e , U n i v e r s i t ~ t E r l a n g e a - N ~ r n b e r g ; 2. Med. Klinik, K l i n i k u m Ndrnberg, Flurstr. 17, D - 8 5 0 0 NHrnberg, FRG. P h a r m a k o l o g i s c h e s I n s t i t u t fdr N a t u r w i s s e n schaftler, Universit~t Frankfurt/Main, D - 6 0 0 0 F r a n k f u r t / M a i n , FRG.

L e h r s t u h l for T o x i k o l o g i e und P h a r m a k o l o g i e d e r Universit~t, Universit~tsstr.22, D8520 Erlangen and I n s t i t u t f~r G e r o n t o l o g i e d e r U n i v e r s i t ~ t H e i m e r i c h s t r . 58, D 8 5 0 0 N N r n b e r g

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THE INFLUENCE OF AGEING ON THE PHARMACOKINETICS OF AN EXTENDED-RELEASE (ER) COMBINATION TABLET OF FELODIPINE AND METOPROLOL S. Lsndahl', B. Lernfelt*, P. Lundborg**, C-G. Reg&rdh**, K. Lidman**, A-M. Tal[berg**

A DOSE-RANGING STUDy IN ELDERLY SALT-REPLETE NORMOTENSIVE SUBJECTS WITH S - 9 6 5 0 , A NEW ANGIOTENSIN CONVERTING ENZYME INHIBITOR

The pharmacokinetics of felodipine (F, Plendil ~) have previously been show~ to be affected by age, Age-dependent changes in metoprolol (M, 8eloken ~) kinetics seem to be of minor clinical importance. The steady state pharmacokinetic profiles of F and M after a fixed ER combination tablet 10+100 mg were compared between elderly hypertensive patients and young healthy men. , Methods: Ten young healthy men (aged 22-32 years) and ten elderly hypertensive patients (2 male, 8 female; aged 7 0 - 7 6 years) took the combination tablet of F+M once daily for 7 days. Blood samples were collected over 24 hours on day 7. The plasma concentrations of F and M were determined by specific gas chromatography methods. Resu ts: The peak (Cmax) and trough (C m ,) plasma concentrat ons the areas under the plasma concentrat on vs hme curves (AUC), and oral p asma clearance (CLoral) were (mean+SD): F Young Cmax (nmol/L) Cmin (nmol/L) AUC (nmol.h/L) CLoral (L/min)

8.5+5,0 2,1:1:1,3 103+55 7,7•

M Elderly 14.5+5.9 5,1• 190+96 4.2+2.7

Yon.0 108+54 50+32 1960•

Elderly 190+97 109+71 n.s. 3696+2118

*p<0.05 Conclusion: Reduced hepatic blood flow and enzyme activity are possible reasons for the altered pharmacokieetiesof F in the elderly. The differences in the pharmacokinetics of M between young and elderly individuals could be explained by the imbalance of slow and rapid metabolizers, that existed between the two study groups. Possibly, the first-pass effect is more pronounced in young subjects due to vasodilalion caused by F. Age-related physiological changes may also play a minor role. *)Geriatric and tongterm Care Medicine, Vasa Hospital, S-4t I 33 G6teborg **)Clinical Pharmacology, Cardiovascular Research, AB H&ssle, S-431 83 M61ndal, Sweden

R.W. Jones, P.Y. Ng, S.J. Barnes, O. CuerX The new angiotensin converting enzyme (ACE) inhibitor S-9650 (Servier Laboratories, France) requires in vivo de-esterification to yield its active metabolite S-I0211. S-9650 was studied in order to establish the dose-ranging activity (using plasma ACE activity as the index) and to assess its tolerance in elderly healthy volunteers. 7 male and 7 female salt-replete normotensive subjects aged 66-74y gave informed consent to participate. Age-matched pairs, one of either sex, received single oral doses of S-9650. The initial dose of O.img was selected as being approximately the dose at which 20% peak inhibition was observed in younger subjects (MacDonald N.J.et al. International Symposium on ACE inhibition, London, 1989). The range of doses administered thereafter was 0.25, 0.5, 0.75, 1.0, 1.5 and 2mg S-9650. Bloods for measurement of ACE activity, renin activity and aldosterone were taken over the 48h following dosage. Plasma and urine were also collected for measurement of parent compound and metabolite levels. Blood pressure and pulse rate were measured over 96h. The tolerance of S-9650 was satisfactory in all subjects. Mild headache and dizziness on standing were reported by a few subjects; there were no cases of orthostatic hypotension. Blood pressure and pulse rate showed no clinically significant change. Peak plasma ACE inhibition occurred about 3-4h after dosage as previously found in young subjects; the range of ACE inhibition achieved was also similar. At 0.Smg S-9650, peak ACE inhibition was approximately 50% and approached maximal (85%) at 1.5mg. At all doses, the percentage of ACE inhibition at 24h was about 50% of the peak value. S-9650 was well tolerated and an effective ACE inhibitor in these elderly subjects showing a similar profile of activity to that in younger subjects. The Research Institute for the Care of the Elderly, St Martins Hospital, Bath BA2 5P.P, U.K.

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PHARMACOKINETICS OF THE ACE-INHIBITOR QUINAPRIL IN Y O U N G A N D E L D E R L Y V O L U N T E E R S . M. N e u b I, K.-O. V o l l m e r I, J. A n d e r t o n , A. D a r r a g h , G.J. F r a n k 2, A.M. H o r v a t h 2, J.Hosie, S.C. O l s o n ~ Q u i n a p r i l is a n e w potent, n o n s u l f h y d r y l , n o n p e p t i d e a n g i o t e n s i n - c o n v e r t i n g e n z y m e (ACE) inhibitor. A f t e r oral a d m i n i s t r a t i o n , q u i n a p r i l (Q) is d e e s t e r i f i e d into its a c t i v e m e t a b o l i t e q u i n a p r i l a t (QA). In two s t u d i e s the p h a r m a c o k i n e t i c s of Q and Q A w e r e i n v e s t i g a t e d in young, n o r m o t e n s i v e s u b j e c t s (YS) and elderly, h y p e r - t e n s i v e p a t i e n t s ( E P ) ( s t u d y A: 15 YS, 15 EP; s t u d y B: 15 YS, 14 EP). YS a n d EP r e c e i v e d 20 or 40 m g (study A) a n d 20 m g (study B) oral Q d o s e s o n c e d a i l y for 28 days. P l a s m a c o n c e n t r a - t i o n s of Q and Q A w e r e a s s a y e d u s i n g an H P L C m e t h o d w i t h f l u o r e s c e n c e d e t e c t i o n . R e s u l t s of b o t h s t u d i e s w e r e in c l o s e accordance. Statistically significant increases in Q A A U C ( 0 - ~ ) a n d tmax, t o g e t h e r w i t h a d e c r e a s e in a p p a r e n t e l i m i n a t i o n rate c o n s t a n t Xz for Q A in EP r e l a t i v e to YS, w e r e d e t e c t e d . In s t u d y A, Q A A U C ( 0 - ~ ) , ~z and t m a x v a l u e s w e r e 87 % greater, 40 % less, and 3 1 % later, r e s p e c t i v e l y , in EP r e l a t i v e to YS. In s t u d y B, the c o r r e s p o n d i n g v a l u e s w e r e 122 % greater, 2 4 less, and 53 % later, r e s p e c t i v e l y . A s t a t i s t i c a l l y s i g n i f i c a n t c o r r e l a t i o n (p<0.001 in b o t h studies) b e t w e e n c r e a t i n i n e and Q A c l e a r e n c e s u g g e s t s t h a t c h a n g e s in rate of Q A e l i m i n a t i o n are a s s o c i a t e d w i t h d e c l i n i n g renal f u n c t i o n r e l a t e d to age r a t h e r t h a n w i t h age itself. * G 6 d e c k e R e s e a r c h Institute, D - 7 8 0 0 Freiburg, FRG; 2 P a r k e - D a v i s P h a r m a c e u t i c a l R e s e a r c h D i v i s i o n , W a r n e r - L a m b e r t Company, A n n Arbor, MI 48105, U S A

DIGOXIN DISPOSITION IN ELDERLY HYPOCHLORHYDRIC HUMANS R.H. Reunin$, J. Hui, A. Chandrasekaran, D.R. Geraets, Y.M.C. Wang, L. Robertson and J.H. Caldwell Digoxin (D3) metabolism is partially mediated by the GI tract. Both major pathways, sugar hydrolysis and bacterial reduction, may be influenced by stomach acid. The hypothesis that hypochlorhydria influences digoxin disposition was tested in 6 normochlorhydric (NC) and 4 hypochlorhydrie (HC) subjects, all but one of whom were >60 yr. Gastric acid secretory function was evaluated by basal and pentagastrin-stimulated acid production. D3 tablets were administered daily until steady-state; then quantitative urine and fecal samples were collected over 3 more days of dosing. Samples were analyzed for D3, 4 sugar-hydrolyzed metabolites and 4 reduced metabolites by fluorescence-derivatization HPLC. Excretion of D3 in urine increased from 37% of the dose in NC to 46% in HC, consistent with decreased hydrolysis of D3 by stomach acid in HC. Conversely, excretion of D3 in feces decreased from 29% in NC to 14% in HC. The altered D3 excretion was significant (p<0;05). Sugar-hydrolyzed metabolites were excreted in most subjects (2-]3%) with no identifiable difference between NC and HC. Reduced metabolites were excreted in only 2 subjects (14-53%), both HC. In each subject D3 was added to anaerobic cultures of (i) feces and (2) an aspirate of upper jejunal fluid. D3 was reduced to dihYdrodigoxin in all but two of the fecal incubates and was not reduced in any of theineubates of jejunal fluid. Thus, in vitro measures of bacterial reduction of D3 were not predictive of in vivo excretion of reduced metabolites. It is concluded that D3 disposition is altered by hypoehlorhydria and that identification of the metabolic mechanisms requires further study. Supported by NIN/NIA grant R01-AG04119, NIH Clin. Res. Center grant RR-34, and Burroughs-Welleome. Ohio State College of Pharmacy, 500 W. 12th Ave., Columbus, OH 43210, USA.

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THE P H A R M A C O K I N E T I C S AND P H A R M A C O D Y N A M I C S OF O I H Y D R O E R G O T O X I N E IN L O N G - T E R M A D M I N I S T R A T I O N TO AOED PATIENTS. M. 6rundmann~ O. K~mpel~ K.. StanGk~ K. Neuwirt~ K. 8 a f a r ~ i k and M. Cech. D i h y d r o e r g o t o x i n e (DHE) is used in g e r o n t o p s y c h i a t r y to i n f l u e n c e the s y n d r o m e of senile de meetia. In the course of 8 weeks, we f o l l o w e d the p h a r m a c o k i n e t i c s of DHE, and in the end of the study, its c l i n i c a l effect and i n f l u e n c e on cerebral blood flow. DHE ( S e c a t o x i n gtt. forte) was a d m i n i s t e r e d in a dose of 2 mg 3 times a day per os. the levels of DHE were det e r m i n e d with the RIA method, and p h a r m a c o k i netic analysis was c a r r i e d out using i- comp a r t m e n t model. C l i n i c a l effect was e v a l u a t e d a c c o r d i n g to C r i c h t o ~ S g e r i a t r i c scale and cerebral blood flow using a s c i n t i l l a t i o n camera with sodium p e r t e c h n a t e as r a d i o a c t i v e indicator. In the e x p e r i m e n t a l group, there were 40 p a t i e n t s - 15 men and 25 women - with organic p s y c h o s y n d r o m e s of a t r o p h i c and vsscu

ABSORPTION OF DIGOXIN AS TABLETS (LANOXIN) AND CAPSULES (LANOXICAPS) IN AN ELDERLY MAN. P. Hooymans, G. van der Aa, W. Hermens, R. Janknegt and J. Lohman. ~ a d y state serum digoxin concentration of 0.66 ng/m] was found in a 87 year old i n - p a t i e n t of a g e r i a t r i c u n i t during digoxin maintenance therapy of one t a b l e t of 0.25 mg d a i l y . In order t o i n v e s t i g a t e an impaired digoxin absorption we compared the steady state digoxin serum concentration a f t e r intravenous (0.25 mg d a i l y ) and oral digoxin admi ni st r at i on. Oral digoxin was given as t a b l e t (Lanoxin, 0.25 mg d a i l y ) and as an encapsulated sol ut i on (Lanoxicaps, 0.1 mg, 2 or 3 d a i l y ) . No data are a v a i l a b l e about the b i o a v a i l a b i l i t y of digoxin capsules in the e l d e r l y . The b i o a v a i l a b i l i t y of oral digoxin in young healthy volunteers is 60-70% f o r t a b l e t s and 90-100% f o r capsules. The dosage regimens were maintained during at least a week to obtain steady state conditions. A blood sample was drawn 12 hr a f t e r dosing on the l a s t day of each treatment period and a 24-hr urine c o l l e c t i o n was obtained. Digoxin concentrat i ons were determined in serum and urine by radioimmunoassay. The r e s u l t s are shown in the t a b l e .

l a r e t & o l o g y ; t h e a v e r a g e age was 7 5 , 4 y e a r s ( 6 1 - B G ) . P h a r m a c o k i n e t i c s was f o l l o w e d i n 8 patients, c e r e b r a l b l o o d f l o w i n 10 p a t i e n t s . Results: AUC 0-24_1 C max -1 T max pmol.h.1 pmol.1 h i. a d m i n i s t r a t i o n 2. week 4. week

i 605 2 085 2 438

177 136 319

0,29 0,5 0,25

B. week

3 280

241

0,57

C l i n i c a l i m p r o v e m e n t was o b s e r v e d in 16 patients with d i s t u r b a n c e of c o n s c i o u s n e s s . Blood flow was a c c e l e r a t e d in 5 p a t i e n t s and in other 5 patients, s l o w - d o w n was observed. When a d m i n i s t r a t i o n of DHE was repeated, an i n c r e a s e in b i o a v a i l a b i l i t y of the drug was observed. O e p a r t m e n t of C l i n i c a l P h a r m a c o l o g y , R e g i o n a l Hospital, 708 52 Osfrava, C z e c h o s l o v a k i a .

L.v. dose (mg) 0.25 serum digoxin level (ng/ml) 1.16 renal digoxin clearance (ml/min) 77 c r e a t i n i n e clearance (ml/min) 60 bioavailability % 100

tablet 0.25 0.66 85 65 57

capsule 0.2 0.3 0.64 1.03 78 83 58 69 68 74

The renal digoxin and creatLnine clearances were stable during the study period. The absorption of digoxin from t a b l e t s was not impaired in t h i s e l d e r l y p a t i e n t , but the absorption from capsules was much less than expected from published data in young healthy volunteers. Pharmacy Department and C l i n i c a l Pharmacokinetics and Toxicology Laboratory, Hospital S i t t a r d , Walramstraat 23, 6131BK S i t t a r d , The Netherlands.

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CORRELATION BETWEEN SERUM CONCENTRATION OF NETILMICIN AND RENAL FUNCTION IN THE ELDERLY. Reiko Aoi, Tadao Ishioka

GASTROINTESTINAL ABSORPTIONOF CLODRONATE(DICHLOROMETHYLENE BISPHOSPHONATE) IN MAN ?.Ylitalo~ K . H o l l i , J.M~nkk~nen, H.A.EIo and M.Karlsson Clodronate is a new bisphosphonate successfully used in the treatment of malignant hypercalcaemia and o s t e o l y t i c bone metastases. I t is known to absorb poorly from gast r o i n t e s t i n a l t r a c t , but systematic studies on i t s absorption are scanty. Since the drug is not metabolized in man and cannot as yet be measured r e l i a b l y in serum, we studied i t s excretion in urine by GLC in three groups of subjects: I) a f t e r single oral dose of 400, 800 and 1,600 mg (Bonefos | Leiras Pharmaceutical Co, Finland) to healthy volunteers (n=11) in a cross-over manner, 2) at the end of one-week treatment periods in cancer patients given 400, 800 and 1,600 mg twice d a i l y , each for I week (n=7), and 3) during the customary therapy of cancer patients treated continually with 400 mg t r i c e d a i l y (n= 10). The excretion percentages (mean• were as follows:

To investigate the infuluence of renal function on the pharmacokinetics of netilmicin(NTL) in the elderly, 100mg of NTL injected intramuselary to 15 patients, ranging in age from 60 to 87 years(mean 74.9 years). Range of serum creatinine(Cr) of these cases remained within 0.6 to 1.5 mg/dl(mean 0.93mg/dl) and creatinine clearance(CCr) within 17 to 89ml/min(mean 48.9ml/min). The serum concentration of NTL was measured by SLFIA method. The peak serum concentrations were obtained at 30 or 60 minutes after administrations, and it ranged from 4.8 to 8.8ug/ml(mean 7.02ug/ml). Ranges of AUC were from 18.1 to 26.6ug.h/ml(mean 21.92ug.h/ml). and TI/2 from 1.55 to 4.04h(mean 2.618h). This TI/2 was significantly prolonged comparing with 1.68h previously obtained from youger generation. The regression lines between AUC and Cr(Y= 21.92+1.25X), AUC and CCr(Y=21.92-0.02X) were calculated, but these regression coefficients were insignificant. The regression lines between TI/2 and Cr(Y=2.62+2.24X), TI/2 and CCr(Y=2.62-0.O3X) were calculated, and these regression coefficients were significant(p
Dosage

400 mg

Single dose I week b . i . d . Continually t . i . d .

2.8 + 1.4 1.1 _+ 1.0 3.1 -+ 2.2

800 mg

I ,600 mg

1.7 +_ 0.7 2.6 • 2.9

2.6 • 1.2 3.1 -+ 4.6

In any of the study groups, there were no s i g n i f i c a n t differences in the excretion percentages between drug doses. Although the involvement of bone deposition in the kinetics of clodronate is not known q u a n t i t a t i v e l y , the results suggest that only a few per cent of the drug is absorbed from gastrointestinal track. Further, the i n t e r and i n t r a i n d i v i d u a l v a r i a t i o n in the absorption is probably large and proposes the drug monitoring in patients treated with oral clodronate. Grant: The Medical Research Council, The Academy of Finland. Department of Pharmacology and Toxicology, University of Kuopio, Tampere University Central Hospital, and Leiras Pharmaceutical Co, P.O.B. 6, SF-70211 Kuopio, Finland.

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PHARMACOKINETICS OF UNCHANGED CISPLATIN IN PATIENTS WITH CANCER N.Yoshimura~ M.Kinoshita~ H.Oqata~ D.Tsujino, T.Takahashi, K.Masuhara, T.Ohno, Y.Tanaka and K.Someya Cisplatin(CDDP) is one of the m o s t a c t i v e a g e n t s available for the treatment of germ cell, ovarian, head and neck, and bladder cancer. However, it has a l s o the d o s e - l i m i t i n g toxicity in a c u t e r e n a l t u b u l a r d a m a g e . To u n d e r s t a n d the disposition of C D D P in p a t i e n t s is t h e f i r s t s t e p for a d j u s t i n g the d o s a g e w i t h o u t the s e v e r e toxicity. Although the active f o r m of C D D P is u n c h a n g e d one, t h e d i s p o s i t i o n of u n c h a n g e d C D D P has not been clarified yet due to non-specific quantitation including active parent and its metabolites. In the present study we applied a specific HPLC method for unchanged CDDP in plasma and urine with post-column reaction detector(K.C.Marsh et ai,1984) with a modification. A plasma ultrafiltrate and urine(100 ~i) were injected onto Hitachi #3013-N column, and CDDP was detected at 2 9 0 nm. M e a n h a l f - l i v e s of C D D P in p l a s m a a n d u r i n e s t o r e d at 37 c w e r e 54.3 m i n a n d 4.5 h o u r , r e s p e c t i v e l y . Patients with cancers(lung and stomach) received CDDP(8O mg/m 2 ) by 2-hour infusion(500 m l of normal saline) after pre-hydration(IL of 4.3% glucose solution containing 0.09% NaCI, 0.149% KCI and 0.224% lactic acid). Post-hydration(IL) was also loaded after infusion. Mean total clearance of C D D P w a s 707.6 m l / m i n and mean renal clearance w a s 124.0 m l / m i n . T h e r a t i o of renal clearance to creatinine clearance was 1.78, s h o w i n g a c t i v e r e n a l t u b u l a r s e c r e t i o n of CDDP. The renal clearance of CDDP was significantly correlated with creatinine clearance(p <0.05). Dept. Biopharm., Meiji Coll.Pharm.,Tokyo and Sch.Med.,St.Marianna University~,Kawasaki,Japan

PHARMACOKINETICS MITOXANTRONE W.D.

Pact,

OF INTRAPLEURALLY

E. M u s e h

and

ADMINISTERED

U. B o d e *

Mitoxantrone (M), a anthraeenedione derivative is u s e d in the t r e a t m e n t o f d i f f e r e n t n e o p l a s t ic diseases i n c l u d i n g b r e a s t cancer, l y m p h o m a and leukemia. Because of high tissue-binding and high therapeutic index M is a f a v o r a b l e d r u g f o r local a n t i n e o p l a s t i c therapy. W h e r e a s the p h a r m a e o k i n e t i c s of intravenous M have been studied extensively , data after intrapleural and intrapericardial a p p l i c a t i o n a r e rare. In the p r e s e n t study the pharmacokinetics of M were s t u d i e d in ? p a t i e n t s r e c e i v i n g M i n t r a pleurally for malignant pleural effusions. P l a s m a l e v e l s a n d M l e v e l s in pleural effusion were determined b y HPLC. P e a k p l a s m a l e v e l s o f M were determined within 2.5 hours after intrapleural (i.pl.) application. High variability was f o u n d with r e s p e c t to p e a k p l a s m a levels, ranging from 10 to 400 ng/ml. The p l a s m a level d e c a y a f t e r i. pl. a p p l i c a t i o n in m o s t p a t i e n t s was best d e s c r i b e d b y a two c o m p a r t m e n t model. In o r d e r to g a i n information on the s y s t e m i c availability of i.pl. a d m i n i s t e r e d M, the a r e a under plasma concentration curves a f t e r i. pl. administration were c o m p a r e d to those o f ? p a t i e n t s r e c e i v i n g i n t r a v e n o u s M. This c o m p a r i s o n s h o w e d a m e a n s y s t e m i c a v a i l a b i l i t y o f a b o u t 20 o f the i n t r a p l e u r a l l v a d m i n i s t e r e d M dose. In addition to p h a r m a c o k i n e t i c d a t a a f t e r i.pl. administration preliminary data after intraper i c a r d i a l a p p l i c a t i o n will be p r e s e n t e d . Medizinische Universit~tsklinik and Universit~tskinderklinik*, D-6300 Bonn

Bonn, V e n u s b e r g Adenauerallee,

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TAMOXIFEN AND METABOLITES IN HUMAN BIOLOGICAL FLUIDS.

ANTHRACYCLINE STIMULATED LIPID PEROXIDATION IN H U M A N C A N C E R C E L L LINES. I Havlik, R Danseyj J Keeping, C Ickinger r W R Bezwoda, F S E Monteaqudo. The c y t o t o x i c a c t i o n of the a n t h r a c y c l i n e s is generally considered to result from an intracellular interaction with DNA. It is still unclear whether anthracyclinestimulated lipid peroxidation plays an additional role and whether differences occur in d r u g r e s i s t a n t , as c o m p a r e d w i t h s e n s i t i v e , cells. In o u r s t u d y b o t h a d r i a m y c i n - r e s i s t a n t and s e n s i t i v e h u m a n t u m o r cell lines w e r e c o m p a r e d with regard to glutathione (GSH) c o n t e n t , adriamycin transport, and drug induced lipid p e r o x i d a t i o n . D r u g i n d u c e d lipid p e r o x i d a t i o n was measured by malonaldehyde (MDA) production. The r a t e of 1 4 C - a d r i a m y c i n u p t a k e w a s s i m i l a r in a d r i a m y c i n sensitive and resistant lines. GSH content was significantly lower in resistant cell lines. MDA production was stimulated in t h e p r e s e n c e of a d r i a m y c i n , e x o g e n o u s N A D P H a n d o x y g e n in r e s i s t a n t c e l l s b u t n o t in s e n s i t i v e c e l l s . D e p l e t i o n o f G S H by the addition of BCNU resulted in an i n c r e a s e of M D A p r o d u c t i o n . L i p i d p e r o x i d a t i o n t h u s a p p e a r s to be r e l a t e d to cellular GSH content. However lipid peroxidation is u n l i k e l y t o b e an i m p o r t a n t m e c h a n i s m of a d r i a m y c i n c y t o t o x i c i t y . Department of Experimental and Clinical P h a r m a c o l o g y and M e d i c i n e , U n i v e r s i t y of the Witwatersrand, Medical School, 7 York Road, 2193 P a r k t o w n , S o u t h A f r i c a

E.A. Lien, E. Solheim, O. Lea, S. Lundgren, S. Kvinnsland and P. M. Ueland Metabolism is a major determinantof drug action. Biotransformation may lead to inactivation and excretion, and some metabolites may have pharmacological effects. This is certainly the case for tamoxifen, which may be regarded as a prodmg, since it is converted into more active metabolites.

Several metabolites of tamoxifen, including 4-hydroxy-Ndesmethyhamoxifen (metabolite BX), 4-hydroxy-tamoxifen (metabolite B), N-desmethyltamoxifen (metabolite X), the primary alcohol (metabolite Y) and N-desdimethyltamoxifen (metabolite Z) were identified, and their concentrations determined in fluids and feces from patients receiving chronic tamoxifen treatment. In serum, tamoxifen itself, and the metabolites X and Z were the prevailing species, but significant amounts of the metabolites B and BX were also detected. Maximum amounts of tamoxifen as well as X, Y, Z and B were found in serum about 3 hours after drug intake. The pioLein binding of tamoxifen and its major serum metabolites (X, Y, Z) was higher than 98 %. Albumin was the main carrier for tamoxifen in human plasma. The concentrations of tamoxifen and its metabolites in pleural, pericardial and peritoneal effusions equalled those detected in serum, corresponding to a effusion/serum ratio between 0.3 and 1. Only trace amounts of tamoxifen and metabolite X were detected cerebrospinal fluid (CSF/semm ratio 0.01). In saliva concentrations of tamoxifen and X exceeded the amounts of free drug in serum, suggesting active transport or trapping of these compounds in saliva. Bile and urine were rich in the hydroxylated, conjugated metabolites (B, BX and Y), whereas in feces unconjugated metabolite B and tamoxifen were the predominating species.

Department of Pharmacology and Toxicology, Universityof Bergen, N-5021 Bergen, Norway

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MONITORING ANTIFOLATE EFFECT BY DETERMINATION OF PLASMA H O M O C Y S T E I N E DURING METHOTREXATE TREATMENT.

THE USE OF DEGRADABLE STARCH MICROSPHERES (DSM) TO TARGET FOTEMUSTINE IN THE TREATMENT OF METASTATIC LIVER TUMOURS R.M.J. Ings, B.H. Gordon, M.P. Hiley, B. Gerard, C. Lucas R. Jochemsen, H. Bleiberg, d.C. Pector, J-P Bizzari and D.B. Campbell The prognosis of metastatic liver tumours tends to be poor since the concentrations of the drug required for effective chemotherapy are also often associated with undesirable systemic toxicity. Thus, any procedure which could target a drug to the site of the tumour, avoiding the systemic circulation should improve the chances of successful therapy. With this objective in mind, fotemustine, a novel nitrosourea developed for the treatment of malignant melanoma, was given to patients with liver tumours, as a bolus at a dose level of 50-75mg.m-2. An escalation dose study is underway based on pharmacokinetic and toxicity data. On the first occasion, fotemustine was administered alone, directly into the hepatic artery via a catheter. One week after, fotemustine was coadministered with degradable starch microspheres supplied by Pharmacia LEO Therapeutics AB, Sweden (DSM - 2 x 300mg per patient 45p in diameter and a half-life of 25min). Venous blood samples were collected at predetermined times after dosing and the pharmacokinetics of fotemustine compared between the two treatments. Although the half-life of fotemustine remained relatively constant (apprex 20 - 30min), the systemic clearance doubled from approx I000 to 2000ml.min-i when DSM were eoadministered with a concomitant increase in the volume of distribution. Since separate in vitro studies demonstrated that DSM may not degrade fotemustine, the apparent increased systemic clearance in extraction of the drug within the confines of the liver would suggest that DSM are successful in containing fotemustine at the site of the tumour and reducing its systemic availability and subsequent toxicity.

H. Refsum, S. Helland, and P. M. Ueland The metabolism of homocysteine is partly dependent on the folate metabolism since regeneration of methionine from homocysteine needs 5-methyltetrahydrofolate as a cofactor. We have recently reported that high doses (1-13 g) of the antifolate drug methotrexate induced a transient increase in plasma and urinary homocysteine in cancer patients. In the present study we investigated the homocysteine metabolism and its response to low dose methotrexate (10-25 mg) in 13 psoriasis patients. The patients had a significantly higher pretreatment homocysteine level than matching controls. There was a small but consistent increase in plasma homocysteine within 48 hours after low-dose methotrexate. The plasma homocysteine returned to pre-treatment levels within one week. This response was repeated after each administration, and was observed at least 8 times in 3 patients. There was no long term effects on plasma homocysteine as reported with high-dose methotrexate. The homocysteine response to methionine loading test was abnormal in four of the patients (not significant), indicating impaired h o m o c y s t e i n e metabolism in these patients. Notably, methotrexate did not affect the plasma profile for homocysteine after methionine loading compared to methionine alone. These results indicate that plasma homocysteine is a sensitive and responsive parameter to antifolate effect.

Clinical pharmacology unit, Department of Pharmacology and Toxicology, University of Bergen, N-5021 Haukeland Hospital, Bergen, Norway

Servier Research and Development Limited, Fulmer Hall, Windmill Road, Fulmer, Slough SL3 6HH, Bucks, U.K.

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INTERSPECIES PHARMACOKINETIC AND TOXICITY SCALINGOF THE ANTITUMORAGENTS, AMSACRINEAND A NEWANALOG(CI-921) J.W. Paxton and L.R. Whitfield The aimwas to investigate relationships between species body weight (W), and pharmacokinetics and t o x i c i t y of the antitumor agents, amsacrine and i t s 4-methyl-6-(N-methylcarboxamide) analog, CI-921. Pharmacokinetic data for both agents was available for mice, rats, rabbits, dogs and humans, and t o x i c i t y data after a single i . v . exposure for mice, rats, rabbits, dogs and humans for CI-921, but only for mice, dogs and humans for amsacrine. Significant allometric equations were obtained for CI-921 between W~nd volume of distribution at steady state (Vss = 1.22WU-O~; r = 0.971, P = 0.006), and total plasma clearance (Cl = 0.91W0.51; r = 0.911, P = 0.031); for amsacrine these equations were Vss = 3.37W0.81 (r = 0.996, P <0.001), and Cl = 2.28W0.46 (r = 0.952, P = 0.012). The dog was a noticeable outlier in the relationship between the maximumtolerated dose in mg/k9 (MTD) of CI-921 and W. Omission of the l a t t e r , resulted in a hiqhly significant allometric relationship, MTD = 23.6W"0.14 (r = 0.988, P = 0.012). A similar equation was not developed for amsacrine due to limited t o x i c i t y data. The prolonged elimination h a l f - l i f e { t 8 9 for CI-921 in the dog and i t s increased susceptib17ity to CI-921 t o x i c i t y suggested a relationship between MTD and kinetic parameters. The best linear correlation was between loge MTD and t% (r = -0.994, P <0.001), from which the following equation was developed, MTD = 47.5e-O'51t89 . Thus, i t was possible to develop allometric equations from animal d a t a which allowed a reasonable estimate of Cl and Vss for CI-921 and amsacrine in patients, despite the compounds being eliminated mainly by biotransformation. However, similar relationships between MTD and Wwere susceptible to variation between species. Species differences in t o x i c i t y were predictable from t~ This study emphasized the importance of pharmacoklnetic data in pre-clinfcal t o x i c i t y and efficacy testing of antitumor agents. Department of Pharmacology, University of Auckland School of Medicine, Auckland, New Zealand

PP 08.28 CYTOKINETIC EFFECTS TAXOL JX Ma a n d

ANTI-TUMOUR

N.A. Habib, D.E. Khoo, S. KelIE, E. A p o s t o l o v , C.B. Wood, W. B a r k s r and R.E. Lister. M a l i g n a n t cell t r a n s f o r m a t i o n is associated w i t h a r e d u c t i o n in the ratio of membrane s t e a r i c to oleic acids (Saturation Index, S.I.) w h i c h is a s s o c i a t e d w i t h a d e c r e a s e in m e m b r a n e rigidity, an increase in cellular metabolism and proliferative activity. l o d o s t e a r i c acid (ISA) has been shown to selectively inhibit colony formation, the s y n t h e s i s of DNA and p r o t e i n s and has been s h o w n to i n h i b i t chemically induced tumour g r o w t h and e s t a b l i s h e d n e o p l a s i a s in rats. We have i n i t i a t e d a Phase I s t u d y in p a t i e n t s with a d v a n c e d g a s t r o - i n t e s t i n a l malignancies refractory to conventional therapy using 5 0 0 m g ISA in r e c t a l suppositories. After 3 months daily treatment no hepatic, renal, bone marrow or local toxicity has been detected. 2 of the first q0 patients developed transient diarrhoea but no other adverse elects were noted and patient a c c e p t a b i l i t y was good. The r a t i o of stearic to o l e i e acids (S.I.) in RBCs was raised by over 50% in 6/q0 patients. These p r e l i m i n a r y r e s u l t s i n d i c a t e that ISA is well t o l e r a t e d at d o s e s which can alter the S.I. in a f a v o u r a b l e direction. Bristol

Royal

I n f i r m a r y , Bristol,

BS2

8HW,

UK.

PP 08.30 OF A N E W

ANTICANCER

DRUG

R Han

Taxol was isolated from the stem bark of Taxus chinensis (Flit.) Rehd. The mechanism of action is very unique. It interacts with the assembly of tubulin ,promotes tubulin polymerization and stabilizes microtubules against depolymerization in vitro. Cell culture experiments demonstrated that at a concentration o f 5 nM t o 40 nM t a x o l decreased the colony forming efficiency of L1210 a n d B16 c e l l s . The mitotic index of L1210 cells was decreased while the cell size was enlarged under the action of taxol. Flow cytometry showed that most of the L12t0 cells in control g r o u p w e r e i n G1 a n d S p h a s e , while cells i n G2+M ( 4C ) w e r e l e s s t h a n 10%. As l o n g a s t h e e x p o s u r e time to taxol was prolonged the cell population i n G2+M p h a s e w a s increased gradually at a concentration o f 25 nM. Sixty hours after the addition of taxol there are o n l y 16% of the c e i l s are in G1 p h a s e and 47~ of the c e l l s p o s s e s s e d 4C or m o r e than 4C DNA c o n t e n t , of w h i c h s o m e p o l y p l o i d y cells a p p e a r e d . It was found i n t e r e s t i n g l y that t h e a c c u m u l a t i o n of c e l l s in G 2 + M was c o n c e n t r a t i o n d e p e n d e n t . M o s t of the L I 2 ] O c e l l s w e r e in G 2 + M and t u r n e d to be p o i y p l o i d y in the p r e s e n c e of 40 nM of taxol. In c o n t r a s t , the G] p e a k a l m o s t disappeared. Institute Medical

F R E E D O M F R O M T O X I C I T Y IN A N O V E L D R U G - I O D O S T E A R I C ACID.

of Materia Medica,Chinese Sciences, Beijing 100050

Academy

of

PHARMACOLOGY AND MOLECULAR IDENTIFICATION OF VASOACTIVE INTESTINAL PEPTIDE (VIP) RECEPTORS IN SIX HUMAN BREAST CANCER CELL LINES. W. Bawab 1, P. de Cremoux2, F. Calv02 and C. Gesoach 1 VIP is a neuropeptide widely distributed in many tissues which exerts its biological effect on endocrine and exocrine secretions via cyclic AMP (cAMP). cAMP is involved in regulating the function and proliferation of normal and transformed epithelial cells. We evaluated VIP receptor activity (1251 VIP, intracellular cAMP generation, adenylate cyclase activity) and pharmacological specificity in six well characterized human breast cancer cell lines. 1251 VIP bound to T-47D ceils in a specific, saturable and reversible manner. Scatchard plots were compatible with the presence of one class of VIP receptors with high affinity (Kd = 4.5 x 10 -10 M, Bmax = 293 fmol/mg protein). VIP and its natural analogues inhibited the binding of 1251 VIP and stimulated cAMP generation in T-47D cells 96-fold (ECbo= 7 x 10 -10 M VIP). Adenylate cyclase activity rose from 72.2 + 14 to 1069 +- 66 pmol cAMP/min/mg protein after the addition of 10 -7 M VIP to T-47D plasma membranes. In agreement with our pharmacological results and the Scatchard analysis of the binding data, sodium dodecyl sulfate polyacrylamide gel electrophoresis o f the solubilized receptor in the T-47D membranes permitted identification of one autoradiographic band with a molecular weight of 69,000. VIP also increased cAMP generation in H4-66B, HSL 53, MCF 7, MDA-MB 231, ZR75-1 cancer ceil lines. These results imply that the VTP receptor-cAMP system has a potential role in human breast cancer cells.

IlNSERM U55, Hbpital Saint Antoine, 75012 PARIS; 2pharmacology Laboratory and INSERM U204, Hdpital Saint Louis, 75010 PARIS, FRANCE

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THALIBLASTINE(TB) - CLINICAL TRIAL AND PHARMACOKINETIC BEHAVIOUR So Yanev and *E. Krusteva Institute of Physiology,Bulg.Acad.Sci. and National Oncological Center, Sofia, Bulgaria

THE U S E O F M E T H Y L P R E D N I S O L O N E , E T O P O S I D E (VP-16) A N D C Y C L I C A M P F O R P U R G I N G IN V I T R O OF BONE M A R R O W IN A C U T E L Y M P H O B L A S T I C L E U K E M I A (ALL). J. P. Skala. P. C. J. R o q e r s a n d W. C. R o d r i a u e z A n o p t i m a l in v i t r o p u r g i n g p r o t o c o l for b o n e marrow harvested from ALL during the first remission, and subsequently cryopreserved for possible autologous transplantation, should e l i m i n a t e e f f e c t i v e l y all t u m o r cells. At the same t i m e it s h o u l d p r e s e r v e a s u f f i c i e n t n u m b e r of n o r m a l p l u r i p o t e n t stem c e l l s n e c e s s a r y for a successful hematopoietic reconstitution. We have d e v e l o p e d a m o d e l s y s t e m u s i n g two A L L cell lines (REH and KM3; non-T, n o n - B l y m p h o b l a s t s ) to t e s t the e f f e c t s of M P in c o m b i n a t i o n w i t h V P - 1 6 an cyclic AMP (8-bromoadenosine 3':5'-cyclic monophosphate); bone marrow specimens of 15 c h i l d r e n n e w l y d i a g n o s e d w i t h A L L w e r e also used. A zero cell v i a b i l i t y (100% kill b y t r y p a n - b l u e e l i m i n a t i o n assay, and a 4 - 1 o g cell r e d u c t i o n as d e t e r m i n e d b y t u m o r - c e l l c l o n o g e n i c assay) w a s a c h i e v e d b y 3-5 h r s i n c u b a t i o n s w i t h 5 m g / m l MP, 20-40 ug/ml V P - 1 6 and 0.i m g / m l CAMP. This p r o t o c o l a l s o c a u s e d p r o n o u n c e d s u p p r e s s i o n of proliferative a c t i v i t y of c e l l s i s o l a t e d from a l i q u o t s of n o r m a l b o n e m a r r o w s p e c i m e n s (donors for a l l o g e n e i c t r a n s p l a n t a t i o n ) . However, longt e r m s u s p e n s i o n c u l t u r e s of t h e p u r g e d n o r m a l bone m a r r o w c e l l s c o m b i n e d w i t h s u b s e q u e n t CFU a s s a y s i n d i c a t e d t h e r e c o v e r y and p r o p a g a t i o n a c t i v i t y of some p l u r i p o t e n t s t e m cells. It s e e m s t h a t t h e a d d i t i o n of h i g h d o s e s of corticosteroids and c y c l i c A M P m a y i m p r o v e t h e efficiency of the pharmacological purging p r o t o c o l s u s e d for t h e r e m i s s i o n b o n e m a r r o w s p e c i m e n s in c h i l d h o o d ALL. The R e s e a r c h Centre, D e p a r t m e n t of P a e d i a t r i c s , U n i v e r s i t y of B r i t i s h Columbia, 950 W e s t 28th A v e n u e , V a n c o u v e r , B.C., Canada, V5Z 4H4.

Thalihlastine(TB) is the generic name of thalicarpine, an aporphine benzylisoquinoline plant alkaloid isolated in Bulgaria from the roots of Thalictrum minus by Nbllov and Dutchewska in 1964o TB have been found to exert a pronounced ~itiepileptic effects on different transplantatic turnout strains in mice, rats and hamsters as hltramuscular Walker carcinosarcoma, subcutaneous Yoshida sarcoma and subcutmneous Jenssen sarcoma.The results from phase I clinical trials of TB in patients with colon cancer,testis teratocarcinoma,thimom,breast cmlcer,lung cancer showed: - the fol89 daily doses were sugKested: initial 10001100 mg/m , optimal - ]100-]200 m~/m Z, maximal - 1400 mg/m 2 method of administration - slow(90-]20 rain) drop infusion once a week for 6 weeks. Side effects:short]asting,reversible told mainly in the time of infusion/cardiovascular disorders - hypotension,rhythm disturbances, local pain at th~ site of TB infusioH/.No chm~ges in haemopoesis were observed. Phase II trials showed that TB induced partial remission in patients with breast cancer (in 8 of 30 ) and ovariml cancer (in 10 of 15 ). Good results had been obtained after TB combination with cyclophosphamide in patients ~ith ovarian cancer and after treatment of patients with lymphoms resistent to vincristine therapy. TB-plasma pharmacokinetic behaviour did not showed significant individual differences,. The very high tissue binding of TB combined with slow rate of elimination (half-life more than !40 h)recomend for practical use TB infusion to he done not in short time intervals because it might lead to dangerous drug acc~nulation.

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EFFECTS OF COMBINATION THERAPY WITH TRADITIONAL CHINESE (KAMPO) MEDICINE AND CARTINOSTATIC DRUGS K. Haranaka, N. Satomi, A. Sakurai, R. Haranaka,' R. Hasegawa and S. Nakagawa Some kinds of traditional Chinese (kampo) preparations (Syo-saiko-to, Zyuzen-taiho-to, etc.) have been proved to have antitumor activities and tumor necrosis factor (TNF) producibility and therapies combining them with them and 0K-432 increased these effects in our previous studies (Cancer I~nunol. Immunother. 20, i, 1985, J. B.R.M. 7, 77, 1988). These results suggested that the antitumor activities and capacity for TNF production of the kampo preparations are probably due iN part to stimulation of reticuloendothorial system (RES), as one of the immunopotentiators. Moreover antitumor effects of therapy combining kampo preparations (Syo-saiko-to, Zyuzen-taiho-to) and TNF, Adriamycin, Cisplatin were investigated, and good curative effects without severe side effects were observed by these combination therapy in transplanted tumor bearing mice. In the groups given kampo medicine, plasma ~-globulin, especially IgG levels, increased and the activation of RES was shown by the morphological findings. Lipoperoxide, glutathione and enzymes related to glutathione metabolism in blood and liver were measured and these results indicated that glutathione metabolism played a role as a superoxide scavenger decreasing the side effects in these therapy. However, these pharmacological actions remain unknown becaurse of the complexity of in vivo defence mechanisms, which involve multiple interacting elements, insufficient characterization of tumor development, and far more complex in vivo mechanisms resulting from the mixed function of kampo medicine. Department of Internal Medicine, Institute of Medical Science, University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108, Japan

ENHANCEMENT OF VINCRISTINE CYTOTOXICITY IN HUMAN LYMPHOMA CELL LINES BY VERAPAMIL ENANTIOMERS AND METABOLITES K. Htiu0ermann, M.F. Wolf~ K. Schumacher and M. Eichelbaum A striking problem In the treatment of cancer with chemotherapeutic agents of natural origin is the development of pleiotroplc or muitldrug-reslstance (MDR). TSURUO et al (Cancer Rea. 41, 1967, 1981) were the first to establish that calcium antagonists can overcome MDR. Various calcium antagonists and beta-blockers have been shown to restore sensitivity to anticancer drugs. The verapamil concentrations required in vitro to overcome MDR are in the order of 6,6 to 2OuM. These concentrations can not be achieved in vivo because of the strong negative dromotroplc and Inotroplc as well as vasodllating effects associated with these high concentrations. The enantiomera of verapamil differ In their pharmacological potency and therefore we have studied the MDR-modulatlng activity of each enantlomer in the human lymphoma cell line MOLT 4B and its vincristine-resistant subline. In MOLT 4B/VCR ECs0 values were in the order of 10uM for (-)S and 20uM for (+)R. Verapamil was also able to enhance cytotoxlclty of non-toxic concentrations of vincristine In senslUve cells. ECs0 values of (-)S and (+)R of 4 and 10uM, respectively, were much lower than those in the resistant cells. Additional experiments with several verapamil metabolitea were performed. Norverapamil was the only metabolite with MDRmodulating activity and displayed ECs0 values in the same range as (-)S-verapamil. Since (+)R verapamil has only 5 to 10% of the negative dromotropic activity of (-)S, (+)R enantiomer might be better suited to achieve the concentrations required in Wvo in order to restore the responsiveness to vincristine in resistant cells and to potentiate the cytotoxicity of lower VCR concentrations in sensitive cells without the severe side effects associated with high R/S verapamil plasma concentrations. Supported by the Robert Bosch Foundation, Stuttgart Dr.Margarete Fischer-Bosch-lnstitut for Klinische Pharmakologie, Auerbachstr. 112, D-7OO0 Stuttgart 50

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LACK OF AMIODARONEEFFECT ON ADRIAMYCINACUTE TOXICITY IN WORKINGRAT HEARTS. C. Lambert C. Mossiat M. Tannibre-Zeller and L. Rochette Adriamycine (Ad) is a potent cYtotoxic agent whose use is limited by a dose-dependent cardiotoxicity. Acute administration of Amiodarone (Am) has been recently shown to enhance s e n s i t i v i t y to Ad in resistant tumors probably by increasing its tissular penetration. The aim of this study was to evaluate whether Am potentiate Ad cardiac t o x i c e f f e c t s . Thirty-two rats were used throughout the protocol and half of them were treated with Am (50 mg/Kg/day for 5 days). Their hearts were perfused via the l e f t atrium with Krebs-Henseleit solution containing, or not, Ad (6 mg/L) resulting in 4 experimental groups: control (C), Am, Ad and Am-Ad. After 40 min of perfusion (T40), the l e f t main coronary artery was tied and the ligature was maintained for 10 min (T50). The ligature was then cut and reperfusion continued f o r 10 min (T60). The cardiac output (CO) (coronary flow + aortic output), heart r a t e (HR) and mean f i b r i l l a t i o n duration induced by the reperfusion (FD) were measured by timed collection and ECG recording. The CO (mL/min, mean • sem) were: TO T40 T5O (isch) T60 (reperf) C 62 • 3 65 • 2 38 • 3 * 38 • 6 * Am 58 • 2 66 • 1 38 • 2 * 57 ~ 2 Ad 62 • 1 47 • 2 * 17 • 1 * 19 • 2 * Ara+Ad 63 • 2 44 • 2 * 19 • 2 * 25 # 3 * 9 p < 0.01 compared with TO values. HR changes were in agreement with the CO m o d i f i c a t i o n s . The FD (sec) noted were 444 • 86, 331 • 73, 66 • 22 and Z2 • 9 f o r the Ad, C, Am and Am+Ad group respectively. I t was concluded that, in our model, Am did not potent i a t e the negative inotropic effect of Ad while Am antiarrhythmic effect was demonstrated. These results would suggest that the clinical acute administration of Am with Ad is not more cardiotoxic than Ad given alone. Dept. o f Pharmacology, University of Montreal, Canada and Faculty of Pharmacy, University of Dijon, France.

METABOLITES OF S-CARBOXYMETHYLCYSTEINE IN URINE: SYNTHESIS AND DETERMINATION BY HPLC D. Snecht. K.P. Kohse. D. Ratge, C.O. Meese~ M. Eichelbaum 1, H. Wisser It has been claimed that a genetically determined polymorphism may be responsible for interindividual differences observed in the metabolic pattern of the mucolytic agent S-carboxymethyl-L-cysteine (CMC). However, the identification of the metabolites (S-oxides, and N-acetylated compounds) was based on a tedious paper chromatography method. Therefore, we developed a rapid, specific and sensitive HPLC method for the routine determination of CMC metabolites in urine by modification of the O P A / M E pre-column derivatization and reversed-phase chromatography procedure for amino acid analysis. Reference compounds (CMC-SO, SMC-SO, N A c - C M C , NAc-SMC, N A c - C M C - S O , and NAc-SMC-SO) were synthesized in high yield and chemically pure form. The R - and S- diastereomers of the S-oxides (CMC-SO, and SMC-SO, respectively) could be obtained separately. Prior to the HPLC analysis, N-aeetylated derivatives were treated with acylase I for 72 h at 37~ which was proven to be sufficient for complete de-acylation. Using our HPLC system, a complete separation and identification of all compounds of interest could be obtained with the exception Of a separation of the SMC-SO diastereomers. In a preliminary study, we investigated the pattern of CMC metabolites excreted in the.urine by 8 healthy volunteers after a single oral dose of 1.5 g CMC. Urine samples could be analyzed directly without sample pretreatment. In the period of 0-8 h following the intake, 12-25 % of the CMC administered was found to be excreted in unchanged form, whereas ca. 1% of the dose was metabolized to CMC-SO. In these subjects, no urinary SMC or SMCSO could be detected. Samples pretreated with acylase did not reveal a different pattern of metabolites. Using a GC/MS procedure, it was found that 8-16% of the drug were metabolized to thiodiglycolic acid (TDGA). From this study, it may be concluded that S-oxides play only a minor role in the metabolism of CMC. However, further investigations in a greater number of subjects will be necessary. Supported by the Robert-Bosch-Stiftuag, Stuttgart. Abt. Kiln. Chem., Robert-Bosch-Krankenhaus, andlM.-Fischer-Boseh Inst. f. Klin. Pharmakol., Auerbaehstr. 110, 7000 Stuttgart 50

PP 08.36

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A SIMPLEAND RAPIDASSAYFOR 3'-AZIDO-3'-DEOXYTHYMIDINEAND ITS OLUCURONIDEIN PLASMA USINGHIGH PERFORMANCELIQUID CHROMAT| F, Kamali and M.D. Rawlins A simpleand rapidmethodfor the simultaneousquantificationof theantiHIV agent,3'-azido-3'-deoxythymidine(AZT) and itsmajor metabolite,the 5'-O-glucuronide(3'-azide-3'-deoxy-5'-13-pyranuronosylthymidine. AZT-glucuronide)in plasma samples by highperformance liquid chromatography (h.p.l.c.)has beendevelopedwhich does not requirelong pre-incubattonor solidmulti-stepextractionprocedures. Thisinvolves proteinprecipitationby trichloroaceticacidwhich isexpectedtodeactivate the human immunodeficiencyvirus (HIY) in samplesof plasma infectedwith thisvirus but ensuringvirtuallycompleterecoveryofAZT and AZ[glucuronide(>97%) in the supernatantfor subsequentanalysisby h,p,l,c. The h,p.l,c,system employeda C 18 reverse-phasecolumn (51~m. 15 cmx 'I

DETERMINATION AND CHARACTERIZATION OF LOW MOLECULAR WEIGHT HEPARINS WITH METACHROMATIC AND E L E C T R O P H O R E T I C M E T H O D S

m m I,D.),The mobilephasewas aeetonitrile:potassiumdihydrogen orthophesphate(2OmM, pH 2,7) 15:85 (v/v) ata flow rateof 0,4 mllmin, AZT, AZT-glucuronide and 13-hydroxyethyl theophylline ( usedas the interna~ standard)were detectedat 267 nm wevelength. The retention times for AZT-glucuronide, 8-hydroxy ethyl theophylline were 930, 10.43 and 16.80 minutes, respectively. The analysis of the samples showeda linear response by the detector for AZT and AZT-glucuronide over the range 0.4311M-97.4pM for AZT and 0.2~M-43,O~M for AZT-glucuronide. Departmentof PharmacologicalSciences,Wolfson UnitofClinical Pharmacology,ClaremontPlace,the University,NewcastleUpon Tyne. NEI 7RU.

The t h e r a p e u t i c use of low m o l e c u l a r weight (LMW) h e p a r i n s r e c e n t l y has b e c o m e more frequent. A i m of this work was to d e v e l o p simple and r a p i d methods for the q u a n t i t a t i o n and characterization of LMW heparins; the metac h r o m a t i c a c t i v i t i e s and e l e c t r o p h o r e t i c b e h a v iour of LMW h e p a r i n s were c o m p a r e d w i t h m e t h o d s p r e v i o u s l y a p p l i e d to UF heparins.-a)Metac.hromThe UV s p e c t r u m of an a q u e o u s solution, of Azur A c h a n g e d after the a d d i t i o n of L M W or UF heparins; the d e c r e a s e of a b s o r b ance at 635 nm was linear w i t h i n c r e a s i n g conc e n t r a t i o n s of h e p a r i n s in the range of i0-i00 u g / m l w i t h a p r e c i s i o n of 4.38%; sensitivity was 5 ug/ml, b ) E ! # c t r o p h o r e s i s .. E. was p e r f o r m ed w i t h p o l y a c r y l a m i d e gels on thin foils; the p h e r o g r a m s w e r e s t a i n e d w i t h t o l u i d i n e blue and e v a l u a t e d w i t h a gel s c a n n e r at 600 nm; h e p a r ins w e r e q u a n t i t a t e d in the range of 2 0 0 - 5 0 0 0 ug/ml; L M W h e p a r i n s s h o w e d a 1.2 fold m i g r a t i o n rate c o m p a r e d to UF heparins; d i f f e r e n t E. patterns were o b t a i n e d for LMW h e p a r i n s of d i f f e r ent origins. In the p r e s e n c e of p o l y b r e n e the heparin bands were not d e t e c t a b l e after E.T h e s e m e t h o d s do not d e t e r m i n e b i o l o g i c a l activities or MW d i s t r i b u t i o n s of h e p a r i n s but a l l o w the d e t e r m i n a t i o n of the c o n c e n t r a t i o n s and the d i f f e r e n t i a t i o n of UF and LMW heparins, and are simple and r a p i d to perform; they are a p p l i e d for the a n a l y s i s of p u r e h e p a r i n s and may be used as a basis for the a n a l y s i s of heparias in b i o l o g i c a l m a t e r i a l s . A b t e i l u n g K l i n i s c h e P h a r m a k o l o g i e der M e d i z i n i schen Universit~tsklinik Heidelberg, Bergheim e r s t r . 58, D - 6 9 0 0 H e i d e l b e r q , FRG

A 228

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THE SIMULTANEOUS CAFFEINE/ANTIPYRINE T E S T IN HUMANS; A SINGLE HPLC ASSAY FOR THE DETERMINAT I O N O F B O T H D R U G S IN P L A S M A

Natural Occurence of Dimethylsuffoxide (DMSO) and its Metabolite Dimethylsulfone (DMSO2) in Humans W. Martin, P.J. Arnold, J. Neckermann, V. Luckow

Antipyrine (AP) and c a f f e i n e (CA) tests are wid e l y u s e d to d e t e r m i n e the e n z y m a t i c o x i d a t i v e degradation capacity of the l i v e r in h u m a n s ; several reports have been published, where these substances were administered separately. Aim of our work was to investigate if the simultaneous administration of b o t h d r u g s to the s a m e s u b j e c t c o u l d f u r n i s h a d d i t i o n a l d a t a of the liver function, important for the evaluation of o t h e r d r u g s d o s e a d j u s t m e n t in patients with liver diseases. Methods: CA and AP w e r e s i m u l t a n e o u s l y a d i i n i s t e r e d o r a l l y at a d o s e of 5 m g / k g CA a n d 15 m g / k g AP r e s p e c t i v e l y and venous blood was collected at different time i n t e r v a l s d u r i n g 0 - 96 h. H P L C a n a l y s i s : Plasma was extracted as d e s c r i b e d before (de Vries et el, J. C h r o m a t o g r . 231, 83, 1982); HPLC was performed with eluents and r e v e r s e d p h a s e c o l u m n as d e s c r i b e d a n d u s i n g p h o t o d i o d e array detection at d i f f e r e n t wavelengths. The peaks were well separated ( r e t e n t i o n times: CA 2.44 m i n and AP 3.13 min), the s e n s i t i v i t i e s w e r e 200 n g / m l for CA a n d AP a n d the p r e c i s i o n w a s < 5 %, n = I0. T h i s a s s a y is simple, s e n s i tive, precise and selective for the given CA/AP-doses and w a s a p p l i e d in p a t i e n t s with different states of liver cirrhosis; no correletion with clinical-chemical parameters (GGT, GOT, GPT) was found. T h i s m e t h o d w i l l be f u r t h e r a p p l i e d to s t u d i e s on the a s s e s s m e n t of the d r u g o x i d a t i v e m e t a b o l i z i n g c a p a c i t y of the l i v e r in n o r m a l s u b j e c t s a n d p a t i e n t s . Abteilung Klinische Pharmakologie der Medizinischen Universit~tsklinik Heidelberg, Bergheimerstr 58, D- 6900 H e i d e l b e r g , F K G

During pharmacokinetic studies with topically applied DMSO we found significant background levels of DMSO and DMSO2 in human plasma. Therefore we carried out fuffher experiments to get more precise information about the frequency distribution of these background concentrations using 100 randomly selected samples. A GC/MS-coupling was used for identification and quantification of DMSO and DMSO2. The GC-equipment consisted of a Hewlett Packard 5980 A gas chromatograph and a Supelcowax 10 fused silica capillary column (3[3 m x 32 mm i,d.) which was directly coupled to the ion source of a Hewlett Packard 5988 A quadrupole mass spectrometer, - Plasma samples were spiked with d6-DMSO as internal standard and extracted with chloroform, followed by injection of the extracts onto the GC column and ionization of the GC effluent, using the positive ion chemical ionization (PCI) with methane as reagent gas. - Selected ion monitoring (SIM) allowed for mass selective detection of characteristic (m+l) - molecular ions of DMSO, DMSO2 and d6-DMSO, respectively. The detection limits were 5 ng/ml for either substance, Calibration lines were linear from 0 to 5 ug/ml for DMSO and from 0 to 50 ug/ml for DMSO2, Results: DMSO concentrations cumulate between 2[3 and 40 ng/ml ranging from 12 to 107 ng/ml whereas DMSO2 levels peak between 700 and 1100 ng/ml, ranging from 308 to 2270 ng/ml. A most probable biochemical pathway explaining these results starts with the methyl group donator dimethylthetin which forms methionin from homocystein. The remaining S-methyl-thioglycolic acid is oxidized to the respective sulfoxide which stabilizes itself by mesomerisation and subsequent decarboxylation leading to DMSO. DMSO is known to be metabolized in part by mixed function oxidation to DMSO2. Pharmakin GmbH, Graf-Arco-Str. 3, 7900 UIm

PP 08.40

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A SIMPLIFIED METHOD FOR A QUANTITATIVE DETERMIN A T I O N OF B E N Z B R O M A R O N E IN H U M A N P L A S M A B Y H P L C ~,.~..!~h~.L...E~..~.=..~ ..Y~ ..... R e c e n t l y we d e s c r i b e d H P L C a n d G C ~ M S m e t h o d s for the simultaneous analysis of benzbromarone (BZBR) and its presumed metabolites bromobenzarone (BRBZ) and benzarone (BZ) in human plasma and urine after oral BZBR administration (de V r i e s et al., J. C h r o m a t o g r . 417 (1987) 420) (i). H o w e v e r , apart from the p a r e n t drug, no m e a s u r a b l e concentrations of BZ and B R B Z w e r e f o u n d (I), b u t two n e w m e t a b o l i t e s w e r e d e t e c t e d ; one of t h e m was c h a r a c t e r i z e d as i'- h y d r o x y b e n z b r o m a r o n e . The necessity to analyse large numbers of samples d u r i n g an e p i d e m i o l o g i c a l s t u d y on the e l i m i n a t i o n of B Z B R in n o r m a l s u b j e c t s , p r o m p t e d us to d e v e l o p a simpler HPLC assay than that d e s c r i b e d b e f o r e (i). A f t e r p l a s m a e x t r a c t i o n (as in (i), u s i n g w a r f a r i n (WA) as i n t e r n a l s t a n d a r d ) , the p l a s m a ext r a c t s w e r e r e d i s s o l v e d in m e t h a n o l and i n j e c t e d in an i s o c r e t i c H P L C system; a L i c h r o s o r b RP 18 column was used for the separation; 70 % acetonitrile in 0.5 % a q u e o u s acetic a c i d was u s e d as e l u e n t at a f l o w r a t e of 1 m l / m i n and U V detection at 313 nm; Calibration plasmas c o n t a i n i n g B Z B R w i t h c o n c e n t r a t i o n s b e t w e e n 0.09 a n d 3 u g / m l w e r e w o r k e d up for e a c h a n a l y s i s series. P e e k s c o r r e s p o n d i n g to W A a n d B Z B R w e r e well separated f r o m those f r o m m e t a b o l i t e s and matrix. This assay results in i m p r o v e m e n t s in a n a l y s i s time, e q u i p m e n t and m a n i p u l a t i o n s with respect to (i) w i t h good sensitivities (0.02 ug/ml), precision (• 5 %) and selectivity. Analyses were validated by GC-MS after m e t h y l a t i n g the e x t r a c t s . Abteilung Klinische Pharmakologie der Medizinischen Universit~tsklinik Heidelberg, Bergheimer Str. 58, D - 6 9 0 0 H e i d e l b e r g , FRG

D I S I T O X I N B I N D I N G AS I N F L U E N C E D BY A L B U M I N C O N C E N T R A T I O N IN P U R E H U M A N A L B U M I N S O L U T I O N S A N D IN H U M A N SERA. D. F r e m s t a d and O. B r m r s The h i g h l y a l b u m i n - b o u n d d r u g d i g i t o x i n is the most c o m m o n l y p r e s c r i b e d d i g i t a l i s g l y c o s i d e i~ Norway. T h e aim of the p r e s e n t study w a s to e l u c i d a t e d i g i t o x i n b i n d i n g in vitro as i n f l u e n c e d by a l b u m i n c o n c e n t r a t i o n , using a n e w e q u i l i b r i um d i a l y s i s techniq%le, w h i c h p r e v e n t s d i l u t i o n by a d d i n g d e x t r a n to the b u f f e r c o m p a r t m e n t . In b i n d i n g e x p e r i m e n t s w i t h i s o l a t e d h u m a n s e r u m a l b u m i n (HSA) d i g i t o x i n u n b o u n d f r a c t i o n i n c r e a sed (1.5; 2.0; 6 . 0 %) w i t h i n c r e a s i n g ~ (6; 7; 8, r e s p e c t i v e l y ) . At pH 7 . 4 an i n c r e a s e in d i g i t o x i n u n b o u n d f r a c t i o n (3.2; 3.3; 3.5; 4 . 3 %) was o b s e r v e d as a l b u m i n c o n c e n t r a t i o n d e c r e a s e d (i00; 50; 30; 15 g / l , r e s p e c t i v e l y ) . This was less t h a n p r e d i c t e d by the law of mass a c t i o n and may be due to p r o t e i n - p r o t e i n - i n t e r a c t i o n . B l o o d (serum) was s a m p l e d from two groups~ h e a l thy" v o l u n t e e r s (control group, age 21-51, n=31, 16 females), and from e l d e r l y p a t i e n t s w i t h low s e r u m a l b u m i n ( g e r i a t r i c group, age 68-94, n=28, 21 f e m a l e s ) . The g e r i a t r i c g r o u p w i t h low a l b u min(34. T + - 3 . 9 g/i) had s i g n i f i c a n t l y (p<0.0005) i n c r e a s e d u n b o u n d d i g i t o x i n in s e r u m (3.3 + - 0 . 4 %), as c o m p a r e d to the c o n t r o l g r o u p w i t h n o r m a l a l b u m i n (44.0 +- 3 . 0 g/l) and u n b o u n d d i g i t o x i n (2.6 +- 0 . 2 %). R e d u c e d serum a l b u m i n c o n c e n t r a t i o n c o u l d only p a r t l y e x p l a i n t h i s i n c r e a s e in ,inbound d i g i t o x i n . An a l t e r n a t i v e e x p l a n a t i o n f o r r e d u c e d d i g i t o x i n b i n d i n g in s e r a from the e l d e r l y may be r e d u c e d a f f i n i t y of t h e i r a l b u m i n for digitoxin. D e p t . o f Clin. Chem., C e n t r a l h o s p i t a l S o g n a n d F j o r d a n e , 6 8 0 0 Ferde; Dept. of P h a r m a c o l o g y , Univ e r s i t y of Oslo, 0 3 1 6 Oslo 3, Norway.

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EXPLORATION OF THE PHARMACOKINETICS OF APD AND SOME OTHER BISPHOSPHONATES. P.Vermeij, J.den Hartigh, D.Blok, R.Langebroek and M.J.Janssen. Bisphosphonates are a new group of drugs which have entered pharmacotherapy recently. Especially 3-amino-l-hydroxypropane-l,l-bisphosphonate (APD) is now, in the Netherlands, the standard drug for the treatment of Paget's disease and malignant hypercalcemia. Due to a lack of analytical methods for the determination of most bisphosphonates in biological media, not much is known about their biopharmaceutics and pharmacokinetics. Owing to their affinity for hydroxylapatite a special distribution pattern in vivo is to he expected, where the accumulation in the bone might be the predominant process. Many analytical problems could be circumvented if the bone -"imag ing 99mTe-lahelle d vkis-h p osph onates could act as model compounds for their respective unlabelled drugs. HPLC methods for the analysis of bisphosphonates, developed in our laboratory, as well as determination of the radiolabelled compounds by scintillation counting were used to study the hiopharmaceutics and pharmacokinetics of APD versus 99mTcAPD. Simultaneous analysis of the amount of labelled and unlabelled bisphosphonates adsorbed in vitro to hydroxylapatite revealed extensive binding (>90%) in the supposedly clinically relevant concentration range. Rapid iv administration of APD and 99mTe-APD to rats resulted in excretion of both compounds in urine. After slow iv infusion however less of the radiolabelled APD was found in the 24h urine. After oral administration of 99mTc-bisphosphonates to rats very small fractions of the label were found in urine (99mTc-APD 0.8%, 99mTc-dimethyl-APD 0.5%, 99mTc-etidronate 1.4%). Also the addition of APD to drinking water resulted in no detectable amounts of APD in urine. These results suggest an enhanced whole body retention at low input rate, probably to be explained by adsorption to hydroxylapatite of the bone. Investigations to explain these results more extensively are in progress. Department of Clinical Pharmacy, University Hospital, Pdjnsburgerweg I0, 2333 AA Leiden, the Netherlands.

EXPERIMENTAL DESIGN FOR OPTIMAL ESTIMATION OF FOPULATIONPHARMACOKINETIC PARAMETERS M.K. Ai-Banna, A.W. Kelman r B. Whitinq The efficiency with which population pharmaeokinetic parameters can be estimated in terms of different sampling schedules has been investigated using Monte Carlo simulation. An underlying one compartment pharmacokinetic model with intravenous bolus input was used to generate concentration data in a population of 50 subjects. Two-and three-point designs were investigated, with the design region (ie, al I possible sampling times) ranging from 0.08 to 20.00 hours. Thirty simulation replicates were generated and ana l y s e d b y t h e p r o g r a m N O N M E M for each of I0 two-point sampling schemes with the first sample time (tl) fixed at 0.08hours and the second sample taken sequentially at 2 hourly intervals, yielding 100 concentration measurements per scheme. This was repeated for each of 9 three-point sampling schemes with the first and third samples fixed at 0.08 and 20.00 (tl, t3) hours respectively and the middle sample (t2] taken sequentia]ly at 2 hourly intervals between t I and t3, yielding 150 concentration measur~rents per scheme. Evaluation of all parameter estinmtes showed that the three-point design was associated with less biased, more preciseand relatively stableparameter estimates and that the gain in efficiency w a s m o s t m a r k e d for the inter- and intra-individual variance parameters. This study emphasises that pharmacokinetic variability can be q u a n t i t a t e d s a t i s f a c t o r i l y w i t h r e l a t i v e l y little patient specific data, but that there is every reason to consider experimental design strategies when population phannaeokinetic studies are proposed. Department of Materia Medica, Stobhill General Hospital, Glasgow, G21 3UW, Scotland.

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A USER EVALUATION OF KODAK EKTACHEM 700XR THEOPHYLLINE SLIDE ASSAY COMPAREDTO EMIT, SERALYZERAND HPLC. A. Magnusson, H. Wallinder, K. Angb~ck, L. Arvanius, L.L. Gustafsson, P. HSglund. During the l a s t few years new methods have been developed for analysing theophylline in serum based on dry chemistry strips and dry chemistry slides. The slide method has been developed for Kodak Ektachem 700XR. The assay is based on the i n h i b i t i o n of beef l i v e r a l k a l i n e phosphatase a c t i v i t y by theophylline which acts as a potent uncompetitive i n h i b i t o r of this isoenzyme. The aim of this work was to perform a comparison of the imprecision and inaccuracy of the Kodak Ektachem theop h y l l i n e assay with those of EMIT and Seralyzer. HPLC was used as a reference method. The within-day and between-day imprecisions for HPLC, EMIT, Seralyzer and Kodak were determined at three d i f f e r e n t concentration levels using pooled patient sera. Table 1. Within-day imprecision, N=IO, mean umol/L (CV%) HPLC EMIT Seralyzer Kodak Low 22.6 (3.1) 22.9 (3.8) 32.9 (5.8) 23.0 (4.6) Medium 50.9 (4.2) 55.7 (2.7) 63.3 (6.2) 55.0 (2.6) High 80.7 (1.7) 81.8 (2.6) 95.4 (5.7) 85.5 (3.9) Table 2. Day-to-day imprecision, N=20, mean umol/L (CV%) HPLC EMIT Seralyzer Kodak Low 20.9 (9.8) 24.8 (9.4) 29.3 (12.2) 27.9 (15.5) Medium 52.2 (4.3) 56.4 (8.4) 64.9 ( 8 . 2 ) 60.2 ( 8 . 3 ) High 79.2 (4.4) 87.7 (7.6) 96.2 ( 9 . 7 ) 90.6 ( 6 . 7 ) Serum samples obtained from theophylline treated patients showed the same pattern with higher values using EMIT, Seralyzer and Kodak compared to HPLC. The deviations were small w i t h i n the therapeutic range, but were of c l i n i c a l importance at t o x i c concentrations. Department of Clinical Chemistry, SSdersjukhuset, S-I00 64 Stockholm, Sweden, and Department of Clinical Pharmacology, Huddinge University Hospital, Karolinska I n s t i t u t e , S-141 86 Huddinge, Sweden.

DESIGN OF POPULATION P H A R M A C O K I N E T I C STUDIES, WITH R E F E R E N C E TO TROSPECTOMYCIN SULPHATE. and D.J.Niehols development programmes detailed pharmacokinetics of the drug in healthy animals and m a n are usually described before patient studies are initiated. There is a growing trend to carry out pharmacokinetic studies in patient populations and, because o f the clinical setting, this usually involves taking few blood samples at 'random' but from a larger n u m b e r of subjects. Monte-Carlo simulations were performed to investigate the use of optimised blood sampling windows, which take account of prior pharmacokinetic information, in preference to random sampling schedules. Replicate serum concentrations at 3 or 4 time points in 100 subjects were generated in SAS, with 15% random error added, using the mean parameter values for a two compartment model of trospectomycin sulphate (derived from healthy volunteer pharmacokinetlc studies). Concentration-time data, for each subject, were fitted to a two compartment model by nonlinear regression and the mean absolute deviations from the true parameter values were calculated. Mean absolute deviations for clearance rate (CL) were <5% of the true parameter value when an optimal sampling schedule was used. Simulations were repeated using sub-optimal sampling schedules (-+50% of ootimal times) In most cases, mean absolute devianons for C L were <10%." Similar simulations were p e r f o r m e d varying the parameter values. For this renally creared drug, taking only 3-4 blood samples within restricted time windows and using conventional curve fitting techniques, would allow a precise, clinically useful estimation of CL for individuals within a population of patients. Pharmaceutical Research Laboratory, U p j o h n Ltd, Fleming Way, Crawley, Sussex, U K .

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PP 08.49

POPULATION KINETICS OF AZT IN AIDS PATIENTS F. Mentr6, A. Mallet, B. Diquet, P. Turk, J.N. Colin and P.Dowd Quantification of interindividual pharmacokinetics variability and determination of the covariates contributing to this variability has proved to improve decision making procedures and individualisation of dosage regimen. Population characteristics of the kinetics parameters of zidovudine (AZT) were estimated using the NPML method (Mallet et al, Biomed Meas Infor Contr,1988,138-145) from observations in 36 AIDS or ARC patients. They received 500 mg of AZT every 6 hours during the first month and then 250 mg. Plasma samples collected on day 1 and day 35 at time 0 (pre-dose), 0.5, 1 and 3 hours after oral administration were assayed by HPLC. The amounts of AZT and GAZT excreted in the urine during the 4, 6 or 24 hours after this dose were also quantified. A classical one compartment model was used to describe AZT kinetics.It involves 3 rate-constants to describe absorption (ka), total elimination (k), urinary elimination (ku) and the voIume of distribution V.The bioavailability (F) being not known, only the population characteristics of the parameters listed in the following table can be estimated.They are comparable to the values previously reported. Day i Day 35 Parameter Mean SD Median Mean SD Median V/F (L) 186.3 200.5 104.9 165.19 207.24 82.79 t k a (h) 0.30 0.43 0.16 0.68 1.18 0.15

POPULATION PHARMACOKINETICS OF TOBRAMYCIN

k (h-l; 0.96 0.71 0.78 1.69 1.51 1.04 F.k u (h-l~ 0.25 0.25 0.18 0.26 0.27 0.17 The distributions of the paramemrs are similar on day 1 and 35 except for the total rate-constant of elimination whose mean increases significantly. As urinary elimination remains stable, those results suggest that metabolism of AZT increases during the first month of therapy in the studied population. Two covariates were incorporated in this preliminary analysis, the body weight at day 1 and the serum creatinine at day 35. At day 1, computations indicate that total and urinary eliminations increase with body weight whereas no relationships were found between V/F (resp. ka) and the body weight. On day 35, a relationship between urinary elimination and serum creatinine was found. The means of the conditional distributions of F.ku were estimated at 0.35, 0.25 and 0.17 per hour for serum creatinine respectively of 60, 80 and 100 gmol/L. InsermU194 et Dpt Pharmacologie, 91 bd HSpital,75634 Paris, France.

L.Aarons,S.Vozeh.M.Wenk,Ph.Weiss,F.Follath It was the purpose of the present study to analyse routinely obtained serum tebramycin concentrations in a large number of patients with a view to estimate the population pbarmacokinetic parameters of tobramycin and to determine an a priori dosing regimen in patients with various degrees of renal function impairment. Data from 97 patients (45 female,52 male;age 16-85yr;weight 42-120kg;creatinine clearance 10-160ml/min) were included in the data analysis. Between 1 and 9 tobramycin concentrations were available per patient. The population pharmacokinetic analysis was performed using the NONMEM computer program (S.L.Beal,L.B.Sbeiner, Am. Star.34,118,1980) with a two-compartment pharmacokinetic model. The best fit to the data was obtained when drug clearance (L/hr) was linearly related to creatinine clearance (ml/min)(propertionality constant: 0.059+/-0.002) and initial volume of distribution (L) was linearly related to body weight (kg)(proportionality constant:0.327+/-0.014). The intersnbject variability in the two parameters was 32% and 3%, respectively, whilst the residual variability amounted to 21% of the tobramycin concentration. The terminal half-life of tobramycin was 26.6+/-9.4br. The pbarmacokinetic model was evaluated in 34 patients not included in the original statistical analysis and it was found that unbiased and precise predictions of tobramycin concentration were obtained. The estimates were used to design a p r i o r i dosage recommendations for tobramycin. Division of Clinical Pharmacology, Department of Medicine, Kantonsspital, Basel, Switzerland

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POPULATION PHARMACOKINETICS OF QUINIDINE IN PATIENTS WITH ARRHYTHMIAS K. Fattinger~ S. Vozeh~ H. R. Ha~ F. Follath A population analysis Was performed with the program NONMEM on the basis of 260 serum concentration (Cs) measurements in 60 patients treated for arrhythmias with oral qninidine sulfate (QS) and/or quinidine bisulfate (QBS, Kin• durilesR). The time course of the Cs was best described by a two compartmentmodel, assuming a drug uptake from the gastrointestinal tract by a zero order process. The time to reach maximum Cs (tma x) was 1.4 (• SE) h for QS and 6.0 (• h for QBS. The oral quinidine clearance (CL) was reduced in patients with severe heart or liver failure. A statistically significant linear relationship was found between CL and the treat• clearance. For patients with normal renal function and no severe heart or liver failure CL was 18.3 I/h and the terminal half-life 10.1 h. The (oral) Vdss was 228 (• i. The QBS preparation had a significantly higher bioavailability than QS, F=1.36 (• The interindividual variability , expressed as coefficient of variation, was estimated for CL, Vdss and tma x of QS as 40 (• %, 76 (• % and 49 4• %, respectively. The remaining intraindividual variability was 22 (i3) %. The results were evaluated in 30 patients not included in the original analysis. An unbiased prediction of b o t h t h e p o p u l a t i o n average and the interindividual variability was found. Based on our results and on optimum therapeutic concentrations for quinldine an 'a priori' dosage was derived using Monte Carlo simulations. These computer simulations revealed that the 90 % prediction interval for quinidine concentrations was substantially larger than the therapeutic range, indicating a need for therapeutic drug monitoring in patients treated with quinidine.

EVALUATION OF MEXILETINE/AMIODARONE INTERACTION AT STEADY-STATE IN PATIENTS USING POPULATION PHARMACOKINETIC ANALYSIS D. Pa,czkowski, W. PopCawska, M. Filipek, I. Chlewicka, D. Sitkiewicz The objective of this study was to investigate the population pharmacokinetics of mexiletine (MEX) using an Extended Nonlinear Least Squares (ELS) computer program (K. Yamaoka, J. Phermacobio.-Dyn. 10, 26, 1987) designed for population pharmacokinetic analysis. Hypothesis testing was performed to determine the influence of coadministration of amiodarone (AD) on the MEX kinetics. The data consisted of 238 steady-state concentration-time points collected in 34 patients with ventricular arrhythmias. These data were divided into two groups: MEX given alone and MEX given with AD. Oral mexiletine, either alone, and with amiodarone, was administered as 200 mg t.i.d. or q.i.d. Amiodarone was taken orally as 200 or 400 mg per day. Data were fitted to a one compartment open model with first order absorption. The population estimates of the basic kinetic parameters were as follows: MEX MEX + AD population parameter Mean f Mean f

Division of Clinical Pharmacology, Department of Medicine, University Hospital (Kantonsspital), CH-4031 Basel, Switzerland

k a (l/h) Vd {L) ke (l/h)

1.12 246 0.134 0.017

0.51 5.36 6.012

1.65 268 0.263 0.016

0.79 4.82 0.13

f inter-individual variations & intra-individual variations Our results suggest intraction between AD and MEX by increasing elimination rate constant (k e) of MEX. Additionally in MEX+AD group large inter-individual variations in ke estimates were observed. Child Health Center, Dept. Diagnostics Lab., Al. Dzieci Polskich 20, 04-736 Warszawa; National Institute of Cardiology, ul. Alpejska 42, Warszawa.

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PHARMACOKINETICS OF FELODIPINE IN LARGE POPULATIONS E Blychert, B Edgar, D Elmfeldt and T Hedner

RECENT PHARMACOKINETICRESEARCHON POPULATIONAND PATIENT RISKGROUPS D. Lee and F. Sit~avisl Four volumes of I~rltish Journal of ~ Pharmacoloav, Clinical Pharmacoloav and TheraPeutics, and European Journal of Clinica! Pharmacoloav were reviewed to characterize non-therapeutic pharmacokinetic studies On selected population and patient groups generally regarded as "risk groups." The overall number and proportion of published studies on the elderly, the neonates, infants and children, pregnant and/or lactating women, and patients with liver or renal function impairment did not change significantly between 1982-83 (38 studies) and 1987-88 (37 studies). Results of the survey indicate that in these two 12-month periods: 1. The majority of the studies (68%) concerned patients with impaired liver or renal function, with a short term trend suggesting an increasing interest in studies on the elderly. 2. The majority of the drugs (75%) have been classified as alternative drugs available on the world market or as investigational drugs. Only 25% of the drugs may be classified as essential drugs (WHO 5th Revised Model List) or drugs to be used in that particular patient subgroup. 3. A majority of the studies were single dose studies (80%) and the study design included control groups (healthy volunteers or another patient group) in 65%. 4. Ethics committee review of the research protocol or informed consent was stated in only 45% of the studies in 1982-83, but this proportion increased to 68% in1987-88. The results of this survey suggest that there is a significant proportion of "me-too" pharmacokinetics research on special populations of healthy individuals and patient risk groups. The demand for pharmacokinetic data in these risk groups pose an ethical dilemma. It is particularly important that pharmacokinetie studies in patients with impaired organ function are limited to drugs which have an established, or at least a potential, role in the treatment of the patient group concerned. Department of Clinical Pharmacology, Karolinska Instituter at Huddinge University Hospital, S-141 86 Huddinge, Sweden

Felodipine is an antihypertensive dihydrepyridine calcium antagonist with selective action on smooth muscle in the arterial resistance vessels. Due to first-pass loss the bioavailability is 15%. It is completely metabonsed via eytochrome P.-450 to the corresponding inactive pyddine metabolite. We have evaluated the pharmaeokinetics of felodipine in 140 individuals (73 healthy subjects and 87 hypertensive patients) aged t 9 to 80 years during steady state treatment with a fast dissolving tablet-formulation of felodipine. The frequency distribution of the individual areas under the plasma concentration of felodipine vs time curve (AUC) in the population does not indicate any btmodal distdbation. This suggests that only one phenotype for the oxidation of felodipine exists. The analysis of the pharmacokinetic characteristics was focused on the influence of age. There was an increase in the AUC, the maximal plasma concentration and the terminal half-life of felodipine with increasing age.The ralio belween the AUC:s of the pyddine melabolite and felodipine decreased with higher age, indicating that the metabolic capacity decreases with age. Conclusion: o These data suggest that there is only one phenotype for the oxidation of felodipine. o With increasing age the metabolic capacity decreases and there is an increase in the AUC, the maximal plasma concentration and the terminal half-life of felodipine. Astra Cardiovascular, Sweden and Department of Clinical Pharmacology, University of Gfteborg, Sweden

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PP 09.01

E S T I M A T I N G T H E B I O E Q U 1 V A L E N C E OF F U R O S E M I D E PRODUCTS USING A POPULATION APPROACH. NC SambQ|, HR Dettelbach. JJ (~erda. RB Stewart. DC Brater. MD Murrav. LB Sheiner. Univ. of California, San Francisco, CA; Univ. of Florida, Gainesville, FL; Indiana Univ., Indianapolis, IN; P u r d u e Univ., W. L a f a y e t t e , IN; & H o e c h s t Roussel Pharmaceuticals, Inc., Somerville, NJ, U.S.A. Purpose/Methods. B i o e q u i v a l e n c e studies, r e q u i r e d f o r r e g u l a t o r y approval of generic drugs, are rarely p e r f o r m e d in the p o p u l a t i o n o f interest, but in y o u n g , h e a l t h y volunteers. This post-marketing study compares the bioavailability of various generic products of furosemide to the trade product (Lasix | in patients who normally receive a diuretic for the treatment of congestive heart failure (CHF) or h y p e r t e n s i o n . A f t e r a c h i e v i n g steady-state on one or more product of furosemide 40 mg (PO and/or IV) once daily, samples of plasma and urine were collected at random times for up to 12 hours postdose. Samples were assayed with reverse-phase HPLC. P r e l i m i n a r y p o p u l a t i o n analysis was performed on data from the first l l patients using NONMEM. Results. The typical time to p e a k p l a s m a c o n c e n t r a t i o n with the generic product was estimated to be significantly ~1~orter than the trade product: 1./ h (95% ~unl'ideu~ limit 1.2-2.3 h) vs 2.3 h (95% confidence limit t.6-3.1 h). The data are thnsfar insufficient to show any difference in percent absorption. This early analysis identified k n o w n influences of age, renal function and C H F on furosemide disposition. E.g., the clearance of oral Lasix | for a typical 60 year old individual with a plasma creatinine of 1.0 mg% is estimated to be 11 L/h; it is estimated to decrease by 120 ml/h for every year greater than 60 and by 1.9 LIh for every rag% plasma creatinine over 1.0. Conclusion. W i t h additional "routine" data (in-progress at this writing), these data will permit bioequivalence to be more critically assessed in a clinically meaningful population. School of Pharmacy, Box 0446, University of California, S a n Francisco, CA. 94143, U.S.A.

BONE CALCIUM CONTENT (BCC) UNDER C Y P R O T E R O N E ACETATE (CPA) AND P E R C U T A N E O U S ESTRADIOL TREATMENT OF HIRSUTISM. M. Vincens% B. Maziere*% B. Agid***, F. K u t t e n n * ~ % P, M a u v a i s - 3 a r v i s * * % It is known t h a t a n d r o g e n ~ h a v e a positive e f f e c t on bone density a t l e a s t in men ( D.T. B a r a n e t al., C a l c i f Tiss. Res. 26,103,1978). Thus, it was i m p o r t a n t to s t u d y bone d e n s i t y during a l o n g - t e r m t r e a t m e n t which c o m b i n e d an a n t i a n d r o gen, C P A , with p e r c u * a n e o u s e s t r a d i o l ( P e r c E2), in h i r s u t e women. M a t e r i a l and m e t h o d s ; One hundred h i r s u t e w o m e n , ( m e a n age= 27,5*_ 6,5 y) w e r e "treated with oral C P A 50 mg+ 1.5 mg p e r c E 2 / d a y f r o m t h e 5th to the 25 th d a y o f ' t h e m e n s t r u a l c y c l e . Bone density was studied by bone c a l c i u m c o n t e n t ( B C C ) in m e t a c a r p i a l bone by in vivo n e u t r o n actJvatkon a n a lysis b e f o r e a n d a f t e r I a n d 2 y e a r s of t r e a t m e n t . Results: BCC values w e r e 0 . 1 7 0 -+ 0.012 g / c m 3 b e f o r e t r e a t m e n t and 0.167_+ 0.17 and 0.165 +- 0.021 g / c m o a f t e r I a n d 2 y e a r s r e s p e c t i v e l y . During this t r e a t m e n t p e r i o d , e s t r a d i o l p l a s m a levels w e r e 75_~ 25 pg/mI. Conclusion : T h e r e was no m o d i f i c a t i o n of B C C u n d e r CPA + P e r c E2. Two h y p o t h e s i s c a n explain the lack of d e c r e a s e in BCC u n d e r this t r e a t m e n t and will be discussed : I) a p r o g e s t o g e n e f f e c t of C P A on bone or ~ 2) a s u f f i c i e n t e f f e c t of e s t r a d i o l p l a s m a levels m a i n t a i n e d over 60 p g / m l to p r o t e c t a g a i n s t bone loss. Endocrinol. P h a r m a c o l o g y . Hopital L a r i b o i s i e r e . P a r i s . F r a n c e ~ D e p t Biology . Hopital F r e d e r i c 3pilot. O r s a y . F r a n c e . *** D e p t Endocrinology. Hopital N e c k e r . P a r i s . F r a n c e .

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PP 09.02 C O M P A R I S O N OF TWO A S S A Y S F O R P A R A T H Y R O I D H O R M O N E IN P A T I E N T S W I T H L I V E R C I R R H O S I S M.H~fig,T.Ledendecker,H.Schmidt-Gayk*,and w. X i r c h When diagnosing hyperparathyroidism (HPT) in patients w i t h renal failure, the i m p a i r e d c l e a r a n c e of m i d r e g i o n a l and c - t e r m i n a l fragments of p a r a t h y r o i d h o r m o n e (PTH) is k n o w n to i n f l u e n c e the r e s u l t s of the w i d e l y used m i d r e g i o n a l and c-term i n a l hPTH(44-68) r a d i o i m m u n o a s s a y . To e v a l u a t e w h e t h e r i m p a i r e d liver f u n c t i o n m i g h t lead to c o n f l i c t i n g r e s u l t s in v a r i o u s P T H - a s s a y s , 36 patients w i t h liver c i r r h o s i s were i n v e s t i g a t e d for their PTH levels in both the m i d r e g i o n a l and a r e c e n t l y d e v e l o p e d assay, d e t e c t i n g the intact h o r m o n e (Blind E. et a l . , C l i n Chem 3 3 , 1 3 7 6 , 1 9 8 7 ) . C o m p a r e d w i t h a c o n t r o l g r o u p m a t c h e d for age and sex with the patients, h P T H ( 4 4 - 6 8 ) - l e v e l s were s i g n i f i c a n t l y i n c r e a s e d in the p a t i e n t s w i t h cirrhosis (P~0.01): The m e d i a n PTH level of the control g r o u p (84• p m o l / l ; ~ I s ~ ) was w i t h i n the normal r a n g e (16-96 pmol/l), w h e r e a s the m e d i a n h P T H (44-68)icvei in the p a t i e n t s w i t h c i r r h o s i s was 165• pmol/l. In c o n t r a s t to these r e s u l t s the m e d i a n value of the intact h o r m o n e a s s a y (4.5~0.6 pmol/l) in the p a t i e n t s w i t h liver c i r r h o s i s did not e x c e e d the n o r m a l r a n g e (2-6 pmol/l). No sign i f i c a n t c o r r e l a t i o n was found b e t w e e n the results of both a s s a y s ( r s = 0 . 0 6 ) . As the assay for the intact h o r m o n e has p r o v e d to be more sensitive c o m p a r e d with a m i d r e g i o n a l assay in d i s c r i m i n a t i n g p a t i e n t s with IIPT from h e a l t h y p e r s o n s (Blind E . : e t a l . , J Clin E n d o c r i n o l M e t a b 67,353, 1988), it is concluded, that the e l e v a t e d hPTH (44-68) levels m i g h t r e f l e c t i m p a i r e d m e t a b o l i s m of PTH f r a g m e n t s in liver cirrhosis. I. M e d i z i n i s c h e Klinik, C h r i s t i a n - A l b r e c h t s - U n i versit~t, S c h i t t e n h e l m s t r . 12, D-2300 Kiel * K l i n i s c h e s L a b o r der C h i r u r g i s c h e n U n i v e r s i t ~ t s k l i n i k , I m N e u e n h e i m e r F e l d lq0,D-6q00 H e i d e l b e r g

PP 09.04 PHARMACOKINETICS OF NANDRONOLONE : HOW LONG CAN IT BE DETECTED IN P L A S M A O R URINE IN YOUNG HEALTffY M E N A F T E R S I N G L E A D M I N I S T H A T I O N ? H. C A P L A I N , E. B E N O I T , J.L. T H O M A S , M.C. H A Z A R D , D. C O U R T O T , J.J. T H E B A U L T .

Nandrolone is a synthetic anabolic steroid administered in man by I.M. route. Its pharmacokinet~cs depends on the rate of h y d r o l y s i s of the e s t e r a d m i n i s t e r e d . The aim of this s t u d y was to evaluate the pharmacokinetics of nandrolone after single administration of 50 mg nandrolone base equivalent in the form of nandrolone undecanoate g i v e n b y I.M. r o u t e in five n o r m a l healthy male volunteers. Blood samples were collected on a d m i n i s t r a t i o n day (day i at 1,2,3,4,5,6,8,10,12,14,16,20,22 hours after administration), and e v e r y m o r n i n g on days 2, 4, 6, 8, I0, 12, 14, 16. Urine samples were co]letted during the f o ] l o w i n g i n t e r v a l s : 24 hours before administration, e v e r y 12 h o u r s on day 1, d a i l y f r o m t h e 2rid t o 1 6 t h day and on d a y s 21, 28 a n d 42. Nandrolone was m e a s u r e d by a s p e c i f i c R.I.A. with antibodies o b t a i n e d from rabbit treated with a nandrolone ]7-hemisuccinate bovine serum albumine conjugate (detection limit : 150 pg/ml). Plasma nandrolone pharmacokinetic parameters were respectively : AUC = 572 + 104 ng/ml.h, Tmax = 86.0 • 6.8 h., Cmax = 1.88 + .32 ng/ml. Nandrolone levels w e r e s i g n i f i c a n t T y differenC from reference l e v e l until respectively : 32 days for plasma and 28 days for urine. In conclusion, this s e n s i t i v e R.I.A. allows for detection of n a n d r o l o n e u n t i l a b o u t one month after single administration. I n s t i t u t ASTER, 15 rue E. MILLON, 7 5 0 1 5 PARIS.

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TIME RELATED DIFFERENCES IN OVARIAN STEROIDOGENESIS FOLLOWING b-Z-fORTAND LON6 TERM HYSTERECTOMY IN CYCLIC RATS M. Hirai, Y. Masubuchi and T. Kumai, Department of PharmaCology, St. Marianna Univ. Sch. of Ned., Kawasaki, Japan

UP REGULATION OF hCG-BINDING SITE OF UTERUS AT EGg-IMPLANTATION STAGE IN RATS Y. Masubuchi, T. Kumai and M. Hirai, Department of Pharmacology, St. Narianna Univ. Sch. of Ned., Kawasaki, JAPAN

Wistar female r a t s were hysterectomized (hyst) at 42 days old and d e c a p i t a t e d 20 (as group t ), 1~5 (as H ) and 414 (as lIl) days following the operation. Groups A and B have been shown normal e s t r o u s c y c l e s in a l l r a t s (88% over) since h y s t , but group 112 shown about 70~ in normal cycle, and 27% in p e r s i s t e n t d i e s t r u s . In ovarian s t e r o i d s , group I showed a s i g n i f i c a n t ( s i g . ) high value of e s t r a d i o l ( E ) , a s i g . low value of 2 0 a - O H - P ( 2 0 a ) and A4-androstenedi one(A) and f u r t h e r , n o n s i g , changes of p r o g e s t e r o n e ( P ) , t e s t o s t e r o n e ( T ) as compared with those of c o n t r o l . GrouplI showed a s i g . high value of E and c o r t i c o s t e r o n e ( B ) , and nonsig, changes of P, 2 0 a , A and T as to c o n t r o l s . ~roup III showed a s i g . high value of 2 0 a , a s i g . low value of E, a tendency of high value of P and of low values of A and T as to c o n t r o l s . Conclussive remarks were as follows; (1) A s i g . increase of ova-count in tube, ovarian weight and ovarian estrogen were observed in s h o r t term as group I , and a s i g . increase of ovarian and plasma estrogen and adrenal B were found in comparative short term as group II , and a s i g . decrease of ovarian estrogen and increase of 20 a were found in long term as group m in compared of those of age-matched c o n t r o l s . (2) Unknown u t e r i n e f a c t o r s with about 800000 and 1000 N.W. may play an indispensable role in c o n t r o l of ovarian f u n c t i o n with aging and r a i s e the p o s s i b i l i t y that enhanced estrogen was involved in med i a t i n g the regulatory mechanisms of n e o p l a s t i c formation in ovary a f t e r short or mild term hysterectomy. (3) Aging e f f e c t s on ovary are continuous, and important changes in o v a r i a n c o n t r o l systems occur throughout the b i o l o g i c a l l i f e span of uterus function, d i r e c t l y or i n d i r e c t l y .

We have reported that hCG or LH inhibit spontaneous contractile a c t i v i t y of r a t uterus(U) indicating hCG/LH receptor in the U. Present work was attempted whether hCC can possess t r a n q u i l i z i n g a c t i o n to the implantation stage of U using such models as c o m b i n a t i o n s - o f the stage of p r e super ovulation by PMS (58hrs l a t e r , p r o e s t r u s ; 53P), the stage of ] u t e i n i z i n g ovary include both the stage of p e s t o v u l a t i o n ( 7 7 h r s l a t e r , e s t r u s ; 77E) and the s t a g e of l u t e i n i z a t i o n (77hrs l a t e r , d i e s t r u s ; 77D) and the s t a g e between the former and the l a t e r ( t h i s can he the stage of implantation), i s o l a t e d U was minced and homogenated at 4 ~ using 50mM Tris-HCl b u f f e r (pH 7.4). The s u p e r n a t a n t s obtained from the c e n t r i f u g a t i o n (800• 4~ was centrifuged ( I b , 0 0 0 X g , 8 O m i n , 4~ and the p e l l e t s was used as membrane f r a c t i o n , lzSI-hCG binding was achieved by 4 hrs incubation at 28~ of the U. Values of the binding a f f i n i t y (Kd) and the binding capacity (Bmax) of these uterus were 0 . 8 4 X 1 0 1~ (Kd) and 0.43fmol/mg protein (Bmax) in contro] diestrus, 0.38• 10M (Kd) and O.20fmol /mg p r o t e i n (Bmax) in the s t a g e of p r e - s u p e r o v u l a t i o n , 0.07XlO-~0N (Kd) and 0.25fmol/mg p r o t e i n (Bmax) in the stage of post-ovulatory ovary, 77E and 0.18 XlO-10M (Kd) and 0.25fmol/mg p r o t e i n (Bmax) in the stage of Iuteinized ovary, 77D. Data represents that d i s s o c i a t i o n constants in 77E and 77D were s i g n i f i c a n t l y higher than that of 53P and that exsistance of hCG binding s i t e with high a f f i n i t y and low capacity in U membrane f r a c t i o n s and r a i s e the p o s s i b i l i t y t h a t hCG/LH can a c t d i r e c t l y to the i m p l a n t a t i o n s t a g e of U as t r a n q u i l i z i n g a c t i o n in v i v o , mediates to these binding s i t e s .

A 233

PP 09.06

PP 09.08

EFFECT OF CGS 16949A ON HUMAN PLACENTAL AND RAT OVARIAN AROMATASE ACTIVITY H,$, Purba and A.S. Bhatnaear CGS 16949A (4.(5,6,7,8-tetrahydrimidazo [1,5-a] pyridin-5-yl) benzonitrile hydrochloride) is a novel, very potent inhibitor of the aromataSe enzyme system both in vitro and in vivo. This study compares the effect of CGS 16949A (10nM) on the above tissues using both, a product isolation method and measurement of tritium release from

MORPHINE INCREASAS ACTH AND B-ENDOEPHIN PLASMA LEVELS DURING HYPOTHERMIA. A.Orts~ M. Lovitz and M.M. Puig. Dpt. Anesthesiology, N.Y.U. Medical Center, New York, 10016, N.Y. The effect of intravenous morphine (MS) on plasma levels of ACTH, Histamine (HIS) and cateeholamines (CA) was determined in two ~roups of dogs at 37 and 30 ~ C. Animals were anes~h~ized with isoflurane and MS (i mg/Kg IV) administered two hours after the desired temperature was obtained, ACTH, B-END, HIS and Ms were determined by RIA and__CA 3evels by REA, Cooling from 3Y to 30=C significan t ~ i n c r e & s e d CA plasma levels. MS produced a significant increase in ACTH~ B-END an HIS, and a reduction in CA levels at 30 but not at 37 C. At all sampling timas~ MS plasma levels were significantly higher at 30 than at 37 eC. Our results show that mild hipothermia enhances the effects of MS on hormonal release 37~C 30PC .Pre Post Pre Post MS (ng/ml) 0 353• 0 648~65a HIS (ng/ml) 12.5• 17.8• 12• 21.8• B-END (pmoi/i)32.3• 34• 27• 44.6• ACTN ( p g / m l ) 106• 143• 140• 296 • CA (pg/ml) 733• 647• 1310• 320• 47b

rla~lea~/l~ea~J~r~Sr~esn~n~ere prepared from freshly delivered placenta and t00Og supernatants were prepared from rat proestrus ovaries. Both preparations were stored frozen at -20~C prior to use. Protein content was estimated by Lowry's method. 4-14C-Androstenedione (4-t4C-A4), 18,28-3H-A4 and 18-3H-A4 were used as substrates for aromatisation. 14C-Estrogens were isolated on TLC and radioactivity was measured on a Berthold TLC analyser. Tritium release from 18,28-3H-A4 and 183H-A4 was measured by liquid scintillation counting. Initial velocity conditions were established which were linear for up to 0.2 mg and 20 rain. Kinetic parameters were determined using Lineweaver-Burk plots. All values are an average of two determinations. 16.26-3H-A4 C~nt CGS

15-3H-A4 Co~t CGS

4-14C-A 4 Cont CGS

~nq_P~igc~nta

Krn 50.4 (nM) Vmax 1.21 (nmol/h/mg) Ki (riM)

662.2 1.80

52.3 1.27

0.83

718.3 1.87

50.1 3.16

0.79

510.1 3.66 1.16

Rat Ovary

Km 234.5 (nM) Vmax 13.7 (pmol/h/mg) Ki (nM)

through origin

40.8

864.0

2.9

3.6

118.2

121.9

430

450

Post: Values obtained five minutes after MS. a, pCO.05 when compared to 37~C group and b, p<0.05 when compared to pre-values in the s~ne group. (Student' s t-test),

0.50

Consistent results were obtained for human placenta using both methods to measure aromatisatbm However, in the rat ovary, only 1r~-3H-A4 produced comparable resutts with the placenta showing that product isolation in rat ovarian preparation is not a suitable method to measure aromatisation. Pharmaceutical Research Department, CIBA-GEIGY Limited, CH-4002 Basel, Switzerland.

PP 09.07 INFLUENCE OF C I N I T A P R I D E ON PROLACTIN SECRETION IN FEMALE VOLUNTEERS Uaena B. Cami J. Farr~ M. ~ d e n a s JM, Se~ura J. Cinitapride is a new benzamide derivative developed by Laboratorios Almirall (Barcelona, Espafia). It has a potent activity as a gastrointestinal prokinetie drug. A current method to evaluate the CNS action of drugs with potential antidopaminergic action is to measure the increase of p r o l a c t i n blood levels in response to treatment. Two clinical trials have been carried out to study the effects of c{nitapride on prolactin secretion. Methods a) Single dose study Six h e a l t h y female volunteers participated in a double-blind, randomized, cross-over study with 3 x 3 latin-square design. During the luteal phase of the menstrual cycle, they received by the oral route a single dose of oinitapride I mg (CIN) or metoclepramide i0 mg (MET) or sulpiride 50 mg (SUL), with a wash-out period of 4 days between treatments. Blood samples were drawn at 0, 0.5, i, 2 and 4 hours and serum prolactin levels (PRL) were analyzed by RIA. b) Multiple dose study Eigth h e a l t h y female volunteers participated in a double-blind, randomized, cross-over study designed to compare the effects of cinitapride I mg /t.i.d. and placebo administered during 14 days in two consecutives luteal phases. Blood samples were obtained on the ist and 14th day. Results a) CIN did not increase the PRL at any time, MET and SUL increase~ significantly the FRL during the period 1 to 4 hours. b) On the first day of therapy, CIN produced a minor increase in PRL, the PRL were always within the normal range (<20 ng/ml). On the 14th day, no statistical difference was found between the two treatments. Dept Pharmacol, Inst Mun Inv Med (IMIM) , P. Maritim 25, 08003-Barcelona, Spain.

PP 09.09 SANDOSTATIN (SMS 201-995) HAS AN ANTIDIURETIC EFFECT IN HEALTHY VOLUNTEERS H. BerthQld* and E. del Pezo Ten male healthy volunteers were investigated to determine whether the synthetic somatostatin analogue Sandostatin (SMS 201-995) has effects similar to those of natural somatostatin on renal water and electrolyte excretion. The study was carried out in three separate placebo-controlled randomized double-blind cross-over trials. The subjects received single subcutaneous irgections of 100 ~g Sandostatin and placebo under conditions of mild diuresis (trial 1), water load with enhanced diuresis (trial 2) and water load with exogenous lysin-vasopressin (5 I.U.s.c.) induced antidiuresis (trial 3). The following parameters were measured: urine flow rate, serum and urine osmolalities, osmolar and free water clearances, creatinine clearance, and excretion rates of sodium, potassium, calcium, cltIoride, and phosphate. A marked antidiuretic effect was observed within two hours after dosing in all three trials. Mean urine flow rates decreased by 45% in trial 1 and by 29% and 31% in trials 2 and 3, respectively (all P<0.05). There were no differences in effects on serum and urine osmolalities between Sandostatin and placebo. Osmolar clearance decreased significantly only in trial 1 (P<0.01). Free water clearance decreased significantly in trial 2 (P<0.05). Sodium excretion decreased by 49%, 48% and 67%, respectively, the differences being significant in trials 1 and 3 (P<0.05). Calcium excretion decreased by 66%, 70% and 54% (all P<0.001). Chloride excretion decreased by 28%, 22% and 44%, the differences being significant in trials 2 and 3 (P<0.05). Potassium excretion, phosphate excretion and creatinine clearance were not significantly altered. These results are in accordance with previous findings with n a t u r a l s o m a t o s t a t i n in m a n u n d e r the condition of high urine flow (corresponding to trial 2 in the present study). We suggest that Sandostatin has a direct vasopressin-like effect at the renal tubule, which is independent from endogenous circulating vasopressin levels. However, the results of trials 1 and 3 are consistent with the involvement of osmolar mechanisms. The question of the clinical relevance of these observations remains open, since during long-term treatment with Sandostatin the drug's antidiuretic effect might be overridden by other mechanisms regulating the water and electrolyte balance. From the Clinical Research Department, Sandoz Ltd., 4002 Basle, Switzerland. *Present address: Preclinical Research, Sandoz Ltd., 4002 Basle, Switzerland.

A 234

PP 09.10

PP 09.12

AVAIL6BILITY AND OXI6EN CONSUMPTION IN THE POLYCYTHEMIA. RE6ULATOR FACTORS OF ERITHROPOIETIN SECRETION. EXPERIMENTAL hPPROhDHTO THE PROBLEM. J~ C. Pice., R~ L. Baistrocchi, R~_.M. AlipEit O___,E_., Bozzini

ALTERED PLASMA PROTEIN BINDING OF DRUGS IN TYPE I NOT TYPE I I DIABETES S. O'Byrne, P. O'Connor, W. C o l l i n s , M. Barry, M. C u l l e r and J. Feely Disease induced changes in plasma p r o t e i n binding may sign i f i c a n t l y a l t e r drug k i n e t i c s and dynamics by influencing the amount of free drug a v a i l a b l e to s i t e s of drug a c t i o n and b i o t r a n s f o r m a t i o n . As l i t t l e is known of a l t e r a t i o n s o f drug binding in diabetes m e l l i t u s we examined plasma binding o f w a r f a r i n ( a c i d i c drug bound to albumin) and lignocaine (a basic drug bound ted, I acid g l y c o p r o t e i n ) . We compared 15 well c o n t r o l l e d Type I ( i n s u l i n dependent d i a b e t i c s , mean glycosylated haemoglobin, HbAI, 8.6% mean age 41 years) to 15 matched c o n t r o l s (HbA1 6.8%). We also determined plasma p r o t e i n binding in 15 T~pe I I (non insulin-dependent d i a b e t i c s , meah 59 years) t r e a t e d with d i e t plus oral hypoglycaemics (n = 8) or d i e t alone (n = 7) and in i0 control p a t i e n t s . Mean HbAI was 9.6% in the former and 6.6% in the l a t t e r (p < 0.05). Drug binding was performed by e q u i l i b r i u m d i a l y s i s f o r 4 h at 37~ Radiolabelled drug s o l u t i o n s ( w a r f a r i n 2.5 pg/ml, lignocaine I pg/m!) were dialysed against NazHPOa/KHzPOa b u f f e r pH 7.45, using a semipermeable membrane. -The mean % (• SEM) p r o t e i n binding of lignocaine and w a r f a r i n in d i a b e t i c s (n = 15, *p < 0.05 from Control) was Control Type I Control Type I I Lignocaine 69• 58• 68• 70• Warfarin 98.8• 98.57~0.03" 98.9• g9.o• Compared with c o n t r o l s there wasno d i f f e r e n c e in p r o t e i n binding of w a r f a r i n or lignocaine in Type I I d i a b e t i c s . In c o n t r a s t there was a 20% increase in free w a r f a r i n and a 37% increase in free lignocaine in Type I d i a b e t i c s . These r e s u l t s suggest t h a t the p r o t e i n binding of w a r f a r i n and lignocaine may be s i g n i f i c a n t l y a l t e r e d in d i a b e t i c s but only in i n s u l i n t r e a t e d p a t i e n t s . Department of Pharmacology and Therapeutics, T r i n i t y College Medical School, St James's H o s p i t a l , Dublin 8, Ireland.

It has been proven by Many authors that polycythemia (P) induced by blood transfusion i n h i b i t s erythropoiasi~. Erithropoiatin is beleived to be the principal regulator of same while ira secretion i5 known to be related to the ratio existing between oxygen supply (availability) end

demand (co'nsumption).

The

present

work

evaluating critically said statement. Male Wistar rats weighihg about 458 g were

two

groups: the

is

aimed at

divided

control group (C) (n=8) and the

into

acute

polyoythemic group (P) {n=B). P was obtained by administering 2.5 ml/l@@ g of a washed erithrocytes suspension by ip route during two consecutive days. In

both g r o u p s hematocrit (HI) (%) was (ml/min/kg) using anOximax 85 equipment,

measured, U02 CO (ml/min/kg)

was measured by thermodilution with a Oardiomax equipment, the a r t e r i a l content of oxygen (C62) ( m l / d l ) , the 48 hs Red Blood Cells Fe59 uptake (RBC) (%) and the Plasma inmunoreactive E r i t h r o p o y e t i n (PIE) (mmol/ml) was also assessed. The venous content (CV2) ( m l / d l ) , the arteriovenous 02 d i f f e r e n c e (Ohm) ( m l / d l ) , ~he oxygen t r a n s p o r t (TO) (ml/min/kg) and the e x t r a c t i o n index (E) were also evaluated. The results were: Ht in D;42.33• in P: B8.6• (Significant difference p<@.@5) (DS). goz in C~

14.22~.41, in P:

13.@4•

D5.

CO in C: 229.50• in P: 181,BO• OS. C~2 in C: 18.5J!2,@8, in P: 2G.55• 2.58 DS, -DAV in C: 6.29• in P:7,2~• TO in 0:42.B3• in P:47.30• CV2 in C: 12.21• in P: 19.26• D5. E in O:8.35• in P: @.27• RBC in C: 38.30• in P: 3,8• OS, PIE in C: 18.73• in P: 4,87• DS. An increase of CV2 and a decrease of V02,CO and PIE ~ith this model of P were noted. Decrease of PIE appears not to be related to modifications of E. Instilute of

Pharmacology end Toxicology L a p l e x S . A . Department of Physiology, Faculty of Odonto!egy of University of Buenos 6ires. Buenos 6ires.

6rgens

PP 09.11

PP 09.13

THE EFFECTS OF GLIMEPIRIDE ON BLOOD GLUCOSE AND INSULIN FOLLOWING A SINGLE ORAL DOSE IN HEALTHY FASTING SUBJECTS M. Nakashima, T. Uematsu, M. Kanamaru and H. Shimizu The s a f e t y and pharmacodynamics o f g l i m e p i r i d e , a new hypoglycemic s u l f o n y l u r e a , were studied in 8 h e a l t h y , f a s t i n g volunteers by a s i n g l e - b l i n d , cross-over design. The subjects received s i n g l e oral doses o f 1.0 mg g l i m e p i r i d e or placebo 5 hours a f t e r b r e a k f a s t and continued to f a s t f o r 4 hours postdrug. Blood glucose level was s i g n i f i c a n t l y decreased u n t i l 4 hours a f t e r a d m i n i s t r a t i o n compared to placebo. In a d d i t i o n , increases in blood glucose 2 hours a f t e r dinner were smaller in the drug group than in the placebo group. On the o t h e r hand, there was no s i g n i f i c a n t d i f f e r e n c e in blood i n s u l i n level between the drug group and the placebo group, i n d i c a t i n g minimal i n s u l i n was released by the drug during f a s t i n g a f t e r a d m i n i s t r a t i o n . No serious symptoms associated with the hypoglycemic a c t i o n o f the drug were observed. Previously, we studied the pharmacodynamics o f s i n g l e oral doses o f 0.25, 0.5, 1.0 mg g l i m e p i r i d e and placebo immediately before b r e a k f a s t in healthy v o l u n t e e r s . As a r e s u l t , increased blood glucose a f t e r b r e a k f a s t was decreased dose-dependently. Increases of blood i n s u l i n in the drug group were l a r g e r than in the placebo group, but t h e i r dose-dependency was not demonstrated. Comparing blood glucose level in these two s t u d i e s , g l i m e p i r i d e was more hypoglycemic at postprandial high blood glucose l e v e l s than during f a s t i n g . Increases o f blood i n s u l i n were smaller than had been expected from the observed decreases o f blood glucose. These f i n d i n g s suggested the hypoglycemic e f f e c t o f g l i m e p i r i d e was induced not only by s t i m u l a t i n g i n s u l i n release but also by i t s e x t r a p a n c r e a t i c a c t i o n in s p i t e o f only s i n g l e dose treatment. Department of Pharmacology, Hamamatsu U n i v e r s i t y School of Medicine, 3600 Handa,cho, Hamamatsu C i t y , Shizuoka 431-31, JAPAN

EFFECTS OF DOSING REGIMEN OF AN ORAL HYPOGLYCEMIC DRUG, GLICLAZ1DE, ON BLOOD GLUCOSE AND INSULIN LEVELS S. Nakano*, M. lequshi**, S. Ohdo*, Y. Fuiii***, T. Fukuda** and N. OcJawa*. Oral hypoglycemic drugs are usually used in postprandial conditions to prevent possible drug-induced severe hypoglycemic symptoms. However, the most appropriate timing of drug administration in re~ation to meal is not clear in these drugs from the pharmacokinetic and pharmacodynamic point of view. This study was designed to clarify the effects of dosing regimen of glic]azide on blood glucose and insulin levels after meal and the relationship between hypoglycemic actions and plasma glidazide concentrations. Eighteen healthy young men participated in one of next two experiments and took 40 mg gliclazide under each experimental condition in a cross-over design. (Experiment I} O 30 min before breakfast, or ~) just after breakfast, under high-(carbohydrate : 90 % ) or low-carbohydrate ( carbohydrate : 9 % ) meal condition. ( Experiment II) CD Just after breakfast, ~) S, (~) 15, @~ 30, or (~ 45 min before breakfast, under high-carbohydrate meal condition. Blood glucose levels significantly increased at I h after highcarbohydrate meal under nondrugged state. This increase was inhibited when the drug was taken 30 min before meal but not when the drug was taken just after meal (p < 0.05). The similar findings were also demonstrated in non-insulin-dependent diabetics. Inhibitory effects on postprandia( increase of blood glucose level were almost identically observed when the drug was taken 5, 15 or 30 rain before meal. The drug was more rapidly absorbed from the gastrointestinal tract when the drug was taken in preprandial condition than in postprandial condition. The results suggest that the gliclazide dosing regimen of taking the drug shortly before meal may produce beneficial hypoglycemir effects without increasing a risk of drug-induced severe hypoglycemic reactions. * Dept. of Pharmacol., Ehime Univ. Sch. Med., Ehime - Ken, 791 02 Japan. ** Dept. of Hospital Pharmacy, Ehime University Hospital, EhimeKen, 791-02 Japan. ** Dept. of Internal Medicine, Ehime Prefectural Central Hospital Matsuyama, Ehime-Ken 790 Japan.

A 235

PP 09.16

PP 09.14 SIMILARITIES

BETWE~

THE EFFECTS OF PINACIDIL

AND

DIAzOXIDE ON PANCREATIC ISLET CELLS. A: Herchuelz, V. Devreux and P. Lebrun Pinacidil is a vasodilator which belongs to the new group of smooth muscle relaxants

: the K + channel

openers. The present study compared the effects of pinacidil and diazoxide,

an hyperglyca~ic

sulfonamide

known to activate the B-cell ATP K + channel, on ionic and secretory events in rat pancreatic islets. Pinacidil and diazoxide provoked a dose-dependent in 86Rb outflow from glucose-stimulated drugs

inhibited

the glucose-and

increase

islets.

Both

tolbutamide-induced

increase in 45Ca outflow and insulin release whilst failing to affect the ionic and secretory responses to K + depolarization.

Pinacidil and diazoxide failed to

affect 86Rb outflow from islets stimulated by the Ca2+-i~176176

A23187"

Pinacidil as well as diazoxide

abolished the glucose-induced did not modifythe rise in close similarities

increase in ~Ca2+ji but 2 ~ i provoked by KCl. The

between the ionic and secretory

events mediated by pinacidil and diazoxide suggest that the two drugs could interfere with the same target site; namely the B-cell ATP-sensitive K + channel. Lab. Pharmacol, U.L.B., B-1000 Brussels, Belgium.

EFFECTS OF NIFEDIPINE AND VERAPAMIL ON INSULIN RELEASE IN RATS G. Ayano~In-Dfilger and L. BHyUkuysal Calcium antagonists are expected to influence the function of endocrin glands since they are known to inhibit the depolarisation-secretion coupling. In fact,nifedipine (N) and verapamil(V) were reported to inhibit insulin release (Giugliano et al,Europ.J.Clin.Pharmacol.18,395,1980 Devis et al,Diabetes 24,547,1975).We investigated the effect of increasing doses of N and V on basal and glucoseinduced insulin release in concious rats.Carotid arteries were cannnlated for blood sampling and the drugs were administered intraperitoneally.Glucese(18/rat ) was administered orally. Serum insulin levels were measured by radioimmunoassay. At 25 and 50 ~g/kg doses N and V did not change basal insulin release,whereas at i00 ~g/kg dose they increased it significantly (n=ll forN and n=5 for V).On the contrary, glucose ~duced insulin release was inhi~tedByboth drugs dose dependently,this effect being significant again at i00 ~g/kg dose(n=5 for both of the drugs). At lO0 ~g/kg dose both N and V cause vasodilatation increasing perfusion of the pancreas and this probably is the cause of increased insulin release at basal glucose levels.On the other hand,it is known that in glucose stimulated beta cells voltage-operated calcium channels are opened,causing sn influx of calcium ions which results in an increased release of insulin (Wollheim and Sharp,Physiol.Rev.81,914,1981). Thus,calcium antagonists are expected to influence mainly the stimulated insulin release, decreasing it, since they are known to inhibit these voltage operated channels. According to the results of the present study,calcium antagonists should be used with caution in diabetic patients since it is evident that these drugs are capable of inhibiting insulin response to appropriate stimuli. Uluda~ Univ. School of Medicine, Dept. Pharmacology G6rHkle,Bursa, TURKEY.

PP 09.15

PP 09.17

LACK OF EFFECT OF NIFEDIPINE AND NITRENDIPINE ON INSULIN RELEASE IN NON-DIABETIC HYPERTENSIVE OBESE PATIENTS:A DOUBLE-BLIND PLACEBO-CONTROLLEDSTUDY

RED BLOOD CELL MELLITUS: EFFECT M.Stanulovic, A.

..IS.UZZAN, P. VALENSI, R. VA$$Y, J.R. ATTALi and 0. PERRET Various data raise the hypothesis that hyperinsulinaemia may contribute to the pathogenesis of atheroma. Calcium antagonists are known to decrease insulin release in vitro. In viva, their effects on insulin secretion and glucose tolerance are controversial. W e performed a double-blind double-dummy controlled trial to study the effectsof nifedipine ( 40 mg per day ; n = I0), nitrendipine ( 20 mg per day ; n = 9) and placebo (n =10) on insulin release and glucose tolerance in 3 parallel groups of obese patients with a mild or transient hypertension, an elevated baseline blood C-peptide level and without biological criteria for diabetes. Treatment lasted one w~k. Patients were asked not to modify their diet during the trial. Their body weight did not vary significantly. A two-hour IV glucose tolerance test was performed twice in every patient, just before the first drug intake and one hour. after the last one. The following parameters were measured or calculated during each test: basal and peak levels of blood glucose, insulin and C-peptide, disappearance rate of glucose, and glucose, insulin and C-peptide areas under the curve. The three groups of patients were comparable for age, sex, body weight and every biological parameter. One way analysis of variance did not show any significantly different evolution of those parameters between the three treatment groups. In conclusion, we failed to show a significant effect of nifedipine or nitrendipine on insulin secretion and glucose tolerance in obese non-diabetic patients. Laboratoire de Pharmecologie Clinique et Exp6rimental&

,Service d'Endocrinologie. H6pital Avicenne 93009 BOBIGNY. FRANCE.

DEFORMABILITY IN OF PHYTOMENADIONE Sabo, L.Lepsanovic

DIABETES

Increased rigidity (or d e c r e a s e d deformability ) of red b l o o d c e l l s (RBC) in Diabetes mellitus (DM) is c o n s i d e r e d to be l i n k e d to microcirculatory complications in this condition. As we found previously that phytomenadione (PH) i n c r e a s e s deformability of RBC, we a d d r e s s e d ourselvas to the question, whether phytomenadione has the same e f f e c t on the RBC of d i a b e t i c p a t i e n t s . The s t u d y was p e r f o r m e d 'in a p a t i e n t s w i t h i n s u l i n - d e p e n d e n t diabetes mellitus, where the erythrocyte deformability was.impaired. Patients received 10 mg/die phyt0menadione im for five days. Deformability was m e a s u r e d w i t h p o l i c a r b o n a t e membranes (Nucleopore) with pore diameter 5 mcm, u n d e r g r a v i t y . The r e s u l t s w e r e e x p r e s s e d as the r a t i o (r) b e t w e e n the f l o w of 1,5 ml (rl) and 2 ml (r2) of RBC s u s p e n s i o n and 1,5 ml of buffer. Phytomenadione increased erythrocyte deformability in patients with diabetes mellitus, l o w e r i n g the v a l u e rl f r o m 3,54+0,84 to 2 , 3 2 + 0 , 6 1 ( p 0,02), and r2 f r o m 7,80+2,41 to 4 , 6 5 + 1 , 0 7 (p 0,01). The results after t r e a t m e n t w e r e s i m i l a r to that f o u n d in h e a l t h y c o n t r o l s (rl 3 , 1 1 + 0 , 9 8 , r2 6 , 5 2 + 3 , 0 4 ) . The r e s u l t s j u s t i f y a f o r m a l c l i n i c a l t r i a l to e s t a b l i s h the c l i n i c a l b e n e f i t of this f i n d i n g in d i a b e t i c s . Department of Pharmacology and Toxicology, School of Medicine, Universit.y of N o v i Sad, Yugoslavia

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THE INFLUENCE OF T O C O P H E R O L E ON ERYTHROCYTE DEFORMABILITY IN PATIENTS WITH DIABETES MELLITUS Sabo,A., M.Stanulovic~ V.Jakovljevic Diabetes mellitus is one of the conditions w i t h i m p a i r e d d e f o r m a b i l i t y of red blood cells (RBC). As we found p r e v i 0 u s l y that t o c o p h e r o l e i n c r e a s e s d e f o r m a b i l i t y of RBCs in rabbits, we addressed ourselvas to the q u e s t i o n whether t o e o p h e r o l e has the same e f f e c t on the RBCs of diabetic patients. The patients with insulln-dependent diabetes mellitus received 100 mg/die tocopherole im for eight days. Deformability of RBCs was m e a s u r e d in two ways:1.with policarbonate membranes ( Nucleopore) w i t h pore d i a m e t e r 5 mcm, u n d e r gravity. The results w e r @ e x p r e s s e d as hhe r a t i o (r) between the flow of 1,5 ml of RBC suspension and 1,5 ml of buffer. 2. w i t h m e a s u r i n g the susceptibility of e r y t h r o c y t e s to c e n t r i f u g a l packing. R e s u l t s were e x p r e s s e d as the ratio (rHtc%) b e t w e e n the c e n t r i f u g a l p a c k i n g of the RBC at centrifugation at 200g and 12000g. Tocopherole increased RBC deformability in patients w i t h d i a b e t e s m e l l i t u s , l o w e r i n g the value r from 3,64+1,62 to 2,32+0,36. The results after t r e a t m e n t w e r e s i m i l a r to that found in h e a l t h y c o n t r o l s ( 3 , 1 1 + 0 , 9 8 , p 0,05). Tocopherole also increased susceptibility of RBC to c e n t r i f u g a l packing, c h a n g i n g the r H t c % from 80,61+6,06 to 88,02+5,13 (p 0,02), (controls 8 5 , 7 9 + 6 , 9 8 ) . The r e s u l t s j u s t i f y a formal c l i n i a l trial to e s t a b l i s h the c l i n i c a l benefit of this finding .in diabetics. Department of Pharmacology and Toxicology, School of M e d i c i n e , U n i v e r s i t y of Novi Sad, Yugoslavia

COMPARATIVE PHARMACOKINETIC-PHARMu~CODYNAMIC STUDY O F PRAVASTATIN AND LOVASTATIN IN HUMANS B. Swanson, H. Pan, A. DeVault, E. Ivashkiv, A. Sugerman, H. Skarzynski, and D. Dollar Pravastatin and lovastatin are HMG-CoA reductase inhibitors. In a crossover study, 20 normocholesterolemic subjects were given 7 c o n s e c u t i v e 40-mg daily doses of drug with a 1-week washout. Bioassay and GC/MS methods were used to measure inhibitor and drug concentrations in serum at steady state. Mean Cmax (ng.eq/mL) and AUC (24 hr, ng.eq-hr/mL) values for active and total (after base hydrolysis) inhibitors (bioassay) are summarized below: Cmax AUC Active Total Active Total PRAVASTATIN 69.1 69.6 204.2 189.3. LOVASTATIN 33.0 c 65.7 176.9 a 284.6 b ap<0.03, bp
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THE INSULIN CONTENTS IN B-CELLS OF CULTIVATED PANCREATIC ISLETS AFTER DIRECT INFLUENCE OF TETRACYCLINE HYDROCHLORIDE G.G. Meyramov, G.T. Tusupbekova

PHARMACOKINE~ICS OF PRAVASTATIN, A NOVEL CHOLESTEROL-

Previous studies have shown that tetracycline h y d r o c h l o r i d e (TH) acting on insulin secretion (V. Poltcrac, Problemi endocrinolmgii, I, 57-61, 1984). We studied the i n s u l i n c o n t e n t s in cytoplasm of B-cells of cultivated pancreatic islets (PI) after direct influence of TH on tissue culture by using some specific histochemical methods: pseudoisocyanine, aldehydfushine and immunofluerescent. The TH has been included in nutria media at 5th day of cultivation 1OO and 150 m i c r o g r / I O O O ml for 3 hours. Control I: PI after influence of glibenclamide causing mobilisation of insulin. Control 2: PI after influence of diahetogenic dithizon. By all methods we have found negative insulin reaction without destruction of B-cells after glibenclamide action. Intensity of fluorescence after pseudoisocyanine and immunofluorescent s~aining decreased from 1,O (normal) to 0.29 ~ 0.06. The destruction of B-cells and negative insulin reaction we observed after action of dithizon. The intensity of fluorescense decreased from 1,O to 0.22 ~ 0.06. After action of TH we have detect normal insulin contents in B-cells. Intensity of fluorescence did not decreased - 0.95 • 0.O8. We did not detect changed of histostructure of PI. Gratitode for reagents to Drs. J. Brawley, E.Horn, B. Kraska (FRG) and to Dr. H. Langisch (FRG). Pedagogical Institute, 470074 Karaganda, 74, USSR.

Pravastatin (P) developed by Sankyo Co. Ltd., is a potent

LOWERING AGENT, IN DOGS K. Sasahara~ T. Nitanai and K. Hoshiyama

new drug for lowering serum cholesterol~1~ninhibition of HMG-CoA reductase, the rate-limiting enzyme for cholesterol biosynthesis. The disposition and pharmaeokinetics of P were investigated in dogs. A sensitive and specific assay procedure using HPLC was developed for the deten~ination of P and its main metabolite in serum and urine. The disposition and pharmacokinetics of P after i.v. and oral doses ranging from 5 mg/kg to 20 mg/kg to dogs were demonstrated to be linear within doses tested. Larger amounts of unchanged P excreted into bile indicated that biliary excretion is the main route of elimination of P. AUC comparisons after i.v. and intraportal infdsion and oral administration indicated that P is well absorbed and hepatic excretion is high, suggesting less systemic burden of P after oral administration. In conclusion, the disposition and pharmacokinetics of P in dogs seems to be well suited for a drug that exerts its pharmacological effect in the liver and intestine. Product Development Laboratories, Sankyo Co. Ltd., 1-2-58 Hiromachi, Shinagawa-ku, Tokyo, Japan

140

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SIMVASTATIN IN PRIMARY HYPERCHOLESTEROLAEMIA P. O'Connor and J. Feely There is increasing evidence of a causal r e l a t i o n s h i p between raised levels of t o t a l cholesterol (TC) and p a r t i c u l a r l y low density l i p o p r o t e i n s (LDL-C) and coronary heart disease. Recent studies suggest that a reduction in LDL-C may be associated with reduced r i s k of heart disease. We examined the e f f e c t of competitive i n h i b i t i o n of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate l i m i t i n g enzyme in c e l l u l a r biosynthesis of c h o l e s t e r o l , with simvastatin in i i patients with primary hypercholesterolaemia. All patients (5 female, 6 male, mean 54• years) were i n i t i a l l y treated f o r at least 6 weeks and maintained throughout on a l i p i d lowering d i e t . During the 8 week study patients received simvastatin 10-20 mg d a i l y with the f o l l o w i n g e f f e c t s (mean • SEM, mmol/l) on plasma l i p i d s including high density lipoprotein-HDL-C and t r i g l y c e r i d e s (TG). Baseline Week 8 p value TC 9.33• 6.6• p < 0.01 LDL-C 7.34• 4.7• p < 0.01 HDL-C 1.09• 1.0• NS TG 1.93• 1.8• NS Weight (Kg) 69.14• 69.5• NS There was a 29% and 36% reduction in TC and LDL-C respectively. While other studies suggest an increase in HDL-C i t is possible that t h i s e f f e c t is seen with longer term therapy. Apart from a t r a n s i e n t elevation in c r e a t i n i n e phosphokinase in one p a t i e n t no adverse e f f e c t s were seen. This and other studies suggest that simvastatin is h i g h l y e f f e c t i v e in lowering C and is well t o l e r a t e d . Department of Pharmacology and Therapeutics, T r i n i t y College Medical School, St James's Hospital, Dublin 8, Ireland.

DOSE LINEARITY OF BECLOBRATE ABSORPTION AFTER APPLICATION OF INCREASING DOSES

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T H E I N F L U E N C E O F L I V E R F U N C T I O N ON P H A R M A C O K I N E T I C S OF B E C L O B R A T E IN P A T I E N T S W I T H H E P A T I T I S AND L I V E R CIRRHOSIS G. W i l l e , J. S c h 6 1 m e r i c h P h a r m a c o k i n e t i c s of b e c l o b r a t e was m e a s u r e d after a s i n g l e oral dose of 200 mg and c o r r e l a t e d to liver f u n c t i o n tests in 17 p a t i e n t s with various h e p a t i c d i s e a s e s : acute h e p a t i t i s (n=5), a l c o h o l i c c i r r h o s i s of the liver w i t h o u t a s c i t e s (n=6), cirrhosis of the liver with a s c i t e s (n=6). As i n d i c a t o r s of d i f f e r e n t liver functions w e m e a s u r e d the c o n c e n t r a t i o n of b i l e - a c i d s , c o f f e i n and z i n c in serum. H e p a t i c c l e a r a n c e and e l i m i n a t i o n - h a l f - l i f e of b e c l o b r a t e were a n a l y s e d in addition. B l o o d s a m p l e s w e r e taken p r i o r to and i, 2, 4, 6, 8, I0, 12, 24, 36, 48, 60 and 72 hours a f t e r g i v i n g beclobrate to f a s t i n g p a t i e n t s . The a c t i v e m e t a b o l i t e of beclobrate, b e c l o b r i n i c acid, was a n a l y s e d by m e a n s of HPLC. P h a r m a c o k i n e t i c d a t a are g i v e n in the table below. ~ o s i s hepatitis cirrhosis cirrh. + ascit. means~SD~ (n=5) (n=6) (n=6)

Cmax clearance t 1/2 bile acids coffein zinc

3.29+3.70 127.8~i01.0 13.4~7.9 174.4+105.6 9.2+16.3 83.8+11.8

Ifflaender U., Gikalov I. The influence of 3 increasing doses of beclobrate, an antilipidemic substance on absorption and elimination was investigated. 9 healthy male volunteers received in a randomized, crossover study oral doses of 100, 200 and 300 mg beclobrate in weekly intervals. Before treatment all volunteers received a standard breakfast. Beclobric acid, the main metabolite was determined in plasma by HPLC; The mean plasma concentrations measured up to 48 hours were distinctly different after each dose. Maximum plasma concentrations were reached after 4.2 h (i00 mg), 3.9 h (200 mg) and 3.7 h (300 mg) (tma x) and amounted to 3.84 mg/1 (i00 mg), 5.82 mg/l (200 mg) and 7.81 mg/l (300 mg) (Cmax), resp. The areas under the concentration/time curve (AUC), extrapolated to infinity were 44.09 (100 mg), 68.94 (200 mg) and 101.08 mg/lxh (300 mg). The Cma x and the AUCs were significantly different (p< 0.05, resp. <0.005) between 1O0 and 300 mg beclobrate, no statistical difference was found between 100 and 200 mg and between 200 and 300 mg. However, if the applied dose was calculated in mg/kg body weight a statist. significant dose depending increase of Cma x and AUC (r = 0.61, resp. 0.67) could be observed. No statistical differences were found with the pharmacokinetic parameters. The mean of the elimination half life (to.5el) increased slightly from 11.5 (100 mg) to 12.9 (200 mg) and 15.1 h (300 mg). The mean transit time (MTT) reflected the trend of the half life. This study indicates that the absorption of beclobrate is proportionaly related to the increase of the oral doses. The elimination of the substance, however, was only insignificantly influenced, no distinct changes were found. Biochemical Depart., Siegfried AG, CH-4800 Zofingen

2.01+1.32 91.2~78.2 27.9Z27.2 140.6+150.4 41.8+39.4 63.7+16.8

3.10+1.49 55.6517.5 13.9Z6.1 79.5+77.6 25.0+29.8 49.6+10.4

A n e g a t i v e c o r r e l a t i o n was found between the concent r a t i o n s of s e r u m bile acids and b e c l o b r a t e c l e a r a n c e in p a t i e n t s with h e p a t i t i s (r= -0.94, p<0.03) and in p a t i e n t s with c i r r h o s i s w i t h a s c f t e s (r = -0.65, p<0.08). In p a t i e n t s with a s c i t e s a c o r r e l a t i o n b e t w e e n c o f f e i n c o n c e n t r a t i o n and c l e a r a n c e (r= -0.51, p<0.15) was found in addition. We conclude, that p o r t o v e n o u s shunting and d e c r e a s e d liver f u n c t i o n o b v i o u s l y d e t e r m i n e the p h a r m a c o k i n e t i c s of b e c l o b r a t e in p a t i e n t s with liver disease. Dept. of Internal M e d i c i n e , U n i v e r s i t y of Freiburg, FRG

INFLUENCE OF FAT CONTENT IN THE FOOD ON THE ABSORPTION OF BECLOBRATE Gikalov I., Ifflaender U. A small and not consistent absorption of beclobrate, a fibric acid deriyative, was observed in preliminary pharmacokinetic studies in fasting persons. The influence of 3 different types of food on the absorption, distribution and elimination of beclobrate were studied. 9 healthy volunteers, 3 women and 6 males, aged 24 to 31 years received a single oral dose of 100 mg beclobrate after 3 different food regimens. The volunteers received the substance after 12 h of fasting or after breakfasts without fat or contenting milk and butter in a randomized and cross-over study. The beclobric acid (BA) the main metabolite of beclobrate, was determined by HPLC. The plasma concentration/time curves of BA showed a distinctly different character depending on the various food regimens. After breakfast with milk and butter the maximal concentration (Cmax = 3.67 + i.i0 mg/l) exceeded the one without fat (Cma x = 1.04 + 0.27 mg/l) and the one after fasting (Cma x = 0.47 ~ 0.34 mg/l). The time of maximal concentration (tmax) was prolonged from 4.7 + 1.7 to 6.4 ~ 6.6 and 14.7 ~ 12.3 h, resp. The area under the concentration/time curve (AUC) decreased from 33.94 13.0 mg/ixh, to 16.93 ~ 6.77 and to 10.24 ~ 6.83 mg/ ixh, resp. After the breakfast with milk and butter the elimination half-life (t~el) was 15.76 ~ 6.93 h. After the meal without fat t~el was prolonged to 36.98 ~ 18.99 h. In the fasting state the low plasma concentrations did not allow to calculate kinetic parameters as no curve with a pronounced maximum was formed. As the absorption is distinctly better and the kinetic handling of beclobrate is more constant after administration of the drug after a diet containing some fat, the substance should be given to hyperlipidemic patients after lunch or dinner. Medical Department, Siegfried AG, CE-4800 Zofingen

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BECLOBRATE: LT-EFFECT ON LIPID AND GLUCOSE METABOLISM

L-CARNITINE ANTAGONIZES INHIBITION OF PALMITOYL-L-CARNITINE MITOCHONDRIAL OXIDATION AND TRIGLYCERIDEB ACCUMULATION INDUCED BY L-AMINOCARNITINE IN RAT HEART AND LIVER F. Maccari, F. Padula, P. Chiodi, M.T. Ramacci and L. Ange-

M. Th. Kris. A. Dettmer and S. Rake~e

10 male and 6 female patients (mean age 59.9 years, mean weight 75.3 kg) with diabetes metlitus type II were treated with 100 mg beclobrate to 28 months at most with a minimum supervision of 10 months. Satisfying results on lipid metabolism were gained in all patients during a preceding clinical trial with 200 nag beclobrate. Evaluation of the efficacy of 100 mg beclobrate was started not prior to 3 months therapy due to different intervalls off-medication following the preceding cfinical study. Regarding total cholesterol, triglycerides, LDL-, HDL-cholesterol and atherogenic index, continuous clinical and biochemical testing showed good LT-effieacy of 100 nag beclobrate. Patients with marked pathological values prior to the long-term treatment exhibited enhanced efficacy. Average reduction of total cholesterol was 16 - 25 %, of triglycerides 16 - 33 %. HDLcholesterol increased on an average of 15 - 18 %, LDL-cholesterol reduction varied between individuals. Tight medical supervision and dietetic behaviour caused a minimal decrease of blood glucose levels. Regular biochemical testing and patients questionnaires demonstrated perfect tolerance. Single pathological biochemical values were not assigned to treatment with beclobrate, unwanted drug effects not documented. Conclusion: After 3 months therapy 100 mg beclobrate exhibited a total normalization of lipid metabolism without influence on blood glucose metabolism and HbAI. Up to 28 months, clinical supervision and biochemical testing showed excellent tolerance. Ortlindestr. 19, D-8000 Mtinchen 81

lacci* L-carnitine activates mitochondrial metabolism of long-chain fatty acids (LFA). Outer and inner AcyI-CoA carnitine-acyltransferase and carnitine translocase are the enzymes involved in this process. L-aminocarnitine is known to inhibit mitochondrial palmitoyltransferase. This investigation was aimed at verifying whether tissue lipid accumulation as induced by L-aminocarnitine may be generated by impairments of the mitochondrial oxidative activity and whether the latter and lipid accumulation as well may be antagonized by administration of L-carnitine. i) Male A.W. rats, 300 g in weight, treated with L-aminocarn/tine (15.6 mg/kg i.p.) and then immediately fasted, showed versus normal animals a significant reduction in mitochondrial oxidation of palmitoyl-L-carnitine in liver (-68%; P < 1%) and heart (-52%; P < 2%), while exhibiting no reduced oxidation of glycidic metabolites (piruvate, succinate). 2) Female A.W. rats, 230 g in weight, treated with L-aminocarnitine (31.25 mg/kg i.p.) and then fasted, showed versus normal animals, a dramatic and significant increase in heart (+1873%; P < 1%) and liver (+7~0~ P < i%o) triglycerides. In both experiments, treatment with L-carnitine (250 mg/kg s.c. per 3 times) restored the biochemical parameters considered to the basal values. Respiratory recovery in heart mitochondria was more than 100% (P <~%) while it was approx. 35% in liver mitochondria (P < 1%). Liver TG were reduced by 6~% (P < i ~ ) with respect to the controls whereas heart TG diminished by 9 ~ (P
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F I S H O I L S R I C H IN O M E G A - 3 F A T T Y A C I D S A L T E R L I P O P R O T E I N C O M P O S I T I O N IN H Y P E R T R I G L Y C E D E M I C P A T I E N T S . M. I n a g a k i , W.S. H a r r i s * a n d K. O g u c h i . F i s h oii(FO) h a s b e e n s h o w n to m a r k e d l y l o w e r l e v e l s of v e r y low d e n s i t y l i p o p r o t e i n ( V L D L ) , b u t n o t t h a t of low d e n s i t y l i p o p r o t e i n ( L D L ) . The p u r p o s e of this s t u d y w a s to i n v e s t i g a t e w h e t h e r F O a f f e c t s the c h e m i c a l c o m p o s i t i o n a n d s i z e d i s t r i b u t i o n of p l a s m a l i p o p r o t e i n ( L P ) . Six patients with hypertriglycedemia r e c i e v e d FO, 12 g m / d a y , for 4 w e e k s . B e f o r e a n d a f t e r FO intake, p l a s m a l i p i d a n d a p o p r o t e i n ( a p o A-I, apo A-II, apo B, a p o C-II, a p o C - I I I , a p o E) l e v e l s w e r e m e a s u r e d . C h a n g e s in LP s i z e d i s t r i b u t i o n w e r e a s s e s s e d by gel f i l t r a t i o n c h r o m a t o g r a p h y . F O lowered VLDL cholesterol(C) levels by 31%(p<0.01) and increased high density lipoprotein-C levels by 2 0 % ( p < 0 . 0 1 ) , b u t d i d n o t c h a n g e the t o t a l or L D L - C levels. F O l o w e r e d p l a s m a t r i g l y c e r i d e ( T G ) l e v e l s b y 4 2 % ( p < 0 . 0 1 ) a n d V L D L - T G l e v e l s b y 51% (p<0.01), b u t d i d n o t c h a n g e L D L - T G levels. S i g n i f i c a n t i n c r e a s e s in apo B ] e v ~ i s ( t b e p r o t e i n c o m p o n e n t of LDL) a n d d e c r e a s e s in a p o C - I I a n d C - I I I w e r e a l s o noted. S i n c e ape B e x i s t s m a i n l y in LDL, and L D L is d e r i v e d f r o m s m a l l V L D L p a r t i c l e s , c h a n g e s in V L D L p a r t i c l e s i z e m a y c o n t r i b u t e to the i n c r e a s e in apo B levels. T h e l i p i d c o n t e n t of s m a l l V L D L p a r t i c l e s w a s r e d u c e d b y o v e r 50%, b u t the p r o t e i n c o n t e n t w a s c o n s t a n t . C h a n g e s in the l i p i d : p r o t e i n r a t i o in V L D L m a y f a v o r the s y n t h e s i s of L D L in p a t i e n t s t a k i n g F O s u p p l e m e n t s . The r e s u l t s s u g g e s t t h a t F O e n h a n c e s the m e t a b o l i s m of V L D L t o w a r d d e s i r a b l e lipoproteins. D e p a r t m e n t of P h a r m a c o l o g y , S c h o o l of M e d i c i n e , S h o w a U n i v e r s i t y . 1-5-8, H a t a n o d a i , S h i n a g a w a - k u , Tokyo, 142, Japan. *: D e p a r t m e n t of M e d i c i n e , U n i v e r s i t y of K a n s a s M e d i c a l C e n t e r , K a n s a s , 66103, U.S.A.

A C T I V A T E D C H A R C O A L IN H Y P E R C H O L E S T E R O L A E M I A : DOSE-RESPONSE RELATIONSHIPS AND COMPARISON WITH CHOLESTYRAMINE P.J. N e u v o n e n , P. K u u s i s t o , H. V a p a a t a l o a n d V. M a n n i n e n T h e d o s e - r e s p o n s e r e l a t i o n s h i p of a c t i v a t e d charcoal in reducing serum cholesterol was d e t e r m i n e d a n d t h e e f f e c t s of c h a r c o a l a n d cholestyramine were compared in the patients with hypercholesterolaemia. Seven patients i n g e s t e d i n t h e c r o s s - o v e r s t u d y c h a r c o a l 4 g, 8 g, 16 g o r 32 g a day, a n d bran, e a c h p h a s e lasting for 3 weeks. Serum total and LDLc h o l e s t e r o l s w e r e d e c r e a s e d (p<0.05; m a x i m a l l y 29 % a n d 4 1 % , r e s p e c t i v e l y ) a n d t h e r a t i o of HDL/LDL-cholesterol w a s i n c r e a s e d (32 g; 121 % ) b y c h a r c o a l in a d o s e d e p e n d e n t m a n n e r . T e n o t h e r p a t i e n t s i n g e s t e d in t h e r a n d o m i z e d o r d e r for 3 w e e k s d a i l y e i t h e r c h a r c o a l 16 g, cholestyramine 16 g, c h a r c o a l 8 g + c h o l e s t y r a m i n e 8 g, o r bran. S e r u m t o t a l a n d L D L - c h o l e s t e r o l s w e r e r e d u c e d (p<0.05) b y c h a r c o a l (23 % a n d 29 %), c h o l e s t y r a m i n e (31% a n d 39 %) a n d t h e i r c o m b i n a t i o n (30 % a n d 38 %). T h e ratio of HDL/LDL-cholesterol was increased (p
A 239

PP 09.30

PP 09.32

Accumulated Evidence for the Hypolipemic and Anti-atherosclerotic Effect of Well Tolerated Vitamin B 6 Derivatives

ERYTHROCYTE CHANGES AFTER DIETARY SUPPLEMENT W I T H O M E G A - 3 F A T T Y A C I D S IN R A B B I T S H. S t e n b e r g - N i l s e n and Io A u r s n e s Rabbits w e r e fed s t a n d a r d p e l l e t d i e t s u p p l e m e n t e d w i t h e i t h e r 2.5 g o m e g a - 3 f a t t y a c i d s f r o m s a l m o n oil (Almarin, A.L.) or an e q u a l a m o u n t of c o r n o i l f o r 6 - 1 2 w e e k s b e f o r e t h e y w e r e e x a m i n e d . It w a s f o u n d t h a t the o s m o t i c r e s i s t a n c e of e r y t h r o c y t e s in the s a l m o n oil g r o u p w a s d e c r e a s e d . In o r d e r to e x p l o r e the c o n s e q u e n c e s of red c e l l m e m b r a n e c h a n g e s , a s p e c i f i c t e s t w a s d e v e l o p e d to d e t e r m i n e r e l e a s e of a d e n i n e n u c l e o t i d e s f r o m e r y t h r o c y t e s . B l o o d s a m p l e s w e r e a d d e d an E D T A - s o l u t i o n w i t h PGE I to p r e v e n t the p l a t e l e t r e l e a s e reaction. P l a t e l e t p o o r p l a s m a w a s o b t a i n e d by d i f f e r e n t i a l o e n t r i f u g a t i o n at 4~ and n u c l e o t i d e s in p l a s m a w e r e q u a n t i f i e d w i t h the l u c i f e r i n / i n c i f e r a s e method. T h i s w a s d o n e i m m e d i a t e l y a f t e r s a m p l i n g , a f t e r 30 m i n r e s t at r o o m t e m p e r a t u r e and a f t e r 60 m i n i n c u b a t i o n at 37~ w i t h shaking. B e f o r e i n c u b a t i o n the w h o l e b l o o d s a m p l e s w e r e a d d e d a m i x t u r e of p y r u v a t e k i n a s e and p h o s p h o e n o l p y r u v a t e at c o n c e n t r a t i o n s w h i c h e m p i r i c a l l y o p t i m i z e d the i n c r e a s e in nucleotides. A s i g n i f i c a n t d i f f e r e n c e b e t w e e n the e f f e c t of c o r n and s a l m o n o i l s (p=0.02, K r u s k a l l - W a l l i s test) as r e g a r d s i n c r e a s e in p l a s m a A D P c o n c e n t r a t i o n d u r i n g the i n c u b a t i o n w a s o b s e r v e d (corn oil 1.84 u m o l / l a g a i n s t s a l m o n oil 0.85). T h e r e w e r e no s i g n i f i c a n t c h a n g e s in ATP. O n the b a c k g r o u n d of the i m p o r t a n c e of a d e n i n e n u c l e o t i d e s in h a e m o s t a s i s , it is conc l u d e d t h a t e r y t h r o c y t e c h a n g e s i n d u c e d by fish oils m i g h t be of c l i n i c a l i m p o r t a n c e . Depts. of P h a r m a c o l o g y a n d P h a r m a c o t h e r a p e u t i c s , U n i v e r s i t y of Oslo,. 0316 B l i n d e r n , Oslo, N o r w a y

U. Speck', W. Schneider 2, S. Okpanyi 2 Despite the numerous investigations Over the past decades, it is still not clear which part vitamin B6 plays in lipid metabolism. A complex derivative of pyridoxal, i.e. magnesium pyridoxal phosphate glutamate (MPPG), has been put to clinical use in lowering serum lipids, and recent clinical trials have confirmed its efficacy (Kirsten et al., Ear J Clin Pharmacol 34, 133-137, 1988). Animal studies were conducted in order to investigate the potential hypolipemic and anti-atherosclerotic effects as well as the tolerance of MPPG and of those derivatives of vitamin B6 which are less complex. MPPG showed hypolipemic activity in rats, in hamsters and - less pronounced - in rabbits. A reduction in the amounts of lipids and calcium incorporated in the aorta could be seen in Watanabe hereditary hyperlipemic rabbits if MPPG was administered along with a cholesterol-enriched diet. Furthermore, MPPG helped remove lipids and calcium from the aortic walls in rabbits, after having been taken off Lheir diets containing cholesterol. Similar results were obtained when using pyridoxamine and pyridoxal glutamate in various animal models, whereas pyridoxine proved to be virtually ineffective under the same conditions. Amino derivatives of vitamin B6 proved to be particularly well tolerated in mice and rats. 'Berlin, 2Steigerwald Arzneimittelwerk GmbH,Darmstadt

PP 09.31

PP 09.33

D O E S A S P I R I N B L O C K THE N I C O T I N I C A C I D I N D U C E D FLUSH?

LIPOPROTEIN B PARTICLE LEVELS DURING PLACEBOCONTROLLED STUDY OF PRAVASTATIN ALONE OR COMBINED WITH CHOLESTYRAMINE VERSUS CHOLESTYRAMINE. C.N. Corder, G. Barbi, E.~Koren. Pravastatin is effective in lowering cholesterol. It suppresses activity of HMG-CoA-Reductase. The effects of Pravastatin 20 mg b.i.d., 40 mg b.i.d., 20 mg b.i.d, combined with Cholestyramine (4 to 20 g/d), Cholestyramine alone (4 to 20 g/d), or placebo were evaluated in 41 patients with primary hypercholesterolemia unresponsive to diet. Lipoprotein B particles (Lp-B) in plasma were determined by enzyme linked immunosorbent assay (ELISA) in a method modified from an ELISA assay for LpAI: Koren et al., Clin. Chem. 33, 38-43 (1987). LpB is expressed as the apolipoprotein B content, rather than by density gradient centrifugation or electrophoresis. Blood samples were taken at the end of 6 weeks dietary baseline, and after 8, 12 and 24 weeks of double-blind study. In addition to LpB, levels of triglycerides, cholesterol, LDL-cholesterol, HDL-cholesterol were measured. Shown are representative values on 20 subjects (19 male, i female) from assays on samples taken at the end of 6 weeks baseline qualification. Results of values from all 41 patients at baseline and during randomized therapy Values are mean • standard deviation (n=20): Age (years) 55.5 + 14 Weight (kg) 86.4 ~ 12.1 Chol. (mg/dl) 289 ~ 30 Triglyceride (mg/dl) 142 T 58 HDL-C (mg/dl) 41 ~ 6 LDL-C (mg/dl) 220 ~ 28 LpB (mg/dl) 148 ~ 34 will be presented. Levels of atherogenic ~pB at baseline were markedly elevated compared to levels expected in normal controls (Alaupovic et al., Clin. Chem. 33, BI3-B27 (1988)!. Clinical Pharmacology, Oklahoma Medical Research Foundation, 825 N.E. 13th Street, Oklahoma City, Oklahoma, 73104, USA.

R.W. Ding,

D. M ~ n c h and E . W e b e r

N i c o t i n i c a c i d (NICA) is a u s e f u l d r u g in the t r e a t m e n t of h y p e r l i p o p r e t e i n e m i a . B u t N I C A f l u s h and GI i r r i t a t i o n are p r o m i n e n t side e f f e c t s w h i c h r e s u l t e d in m o r e t h a n one t h i r d of p a t i e n t s N I C A t h e r a p y to be stopped. R e c e n t ly K a i j s e r et al. c o u l d d e m o n s t r a t e in h e a l t h y v o l u n t e e r s t h a t the v a s o d i l a t o r y NICA effect c o u l d be m a r k e d l y d e c r e a s e d b y the p r e t r e a t m e n t w i t h the p r e s t a g l a n d i n - s y n t h e s i s i n h i b i tor i n d e m e t h a c i n . It w a s t h e r e f o r e the a i m of this s t u d y to m e a s u r e the d i m i n u t i o n of the NICA flush under aspirin by using thermography. M e t h o d s : Six h e a l t h y s u b j e c t s r e c e i v e d 200 m g N I C A as o r a l s o l u t i o n s w i t h and w i t h o u t p r e t r e a t m e n t of 5 O O m g a s p i r i n on two o c c a s i o n s . Skin temperature was analyzed any minute after the a d m i n i s t r a t i o n of N I C A b y u s i n g a t h e r m e g r a p h i c c a m e r a and the H e i d e l b e r g P o l y p , a c o m p u t e r u n i t d e v e l o p e d b y the H e i d e l b e r g d e p a r t m e n t of P h y s i c s . T h e d i s t r i b u t i o n of the N I C A f l u s h o v e r the b o d y w a s s t u d i e d and q u a n t i t a ted by d i v i d i n g h e a d ,neck and c h e s t into d e f i n e d s e g m e n t s .For q u a n t i t a t i o n the m a x i m u m increase of s k i n t e m p e r a t u r e a n d the A U C of the t e m p e r a t u r e curve were determined during NICA flush and the r e s u l t s w i t h and w i t h o u t p r e t r e a t m e n t w i t h a s p i r i n c o m p a i r e d w i t h the p a i r e d t-test. R e s u l t s : N o c o n s i s t e n t t r e n d c o u l d be o b s e r v e d for the u s e of a s p i r i n . N I C A f l u s h w a s d i m i n i s h ed u n d e r a s p i r i n o n l y w i t h 2 s u b j e c t s . It was evenaggravated w i t h two o t h e r s u b j e c t s . D i v i s i o n Clin. P h a r m a c o l g y , H e i d e l b e r g Univ. Med. Center ,Bergheimerstr.58,D-69OO Heidelberg,FRG.

A 240

PP 09.34

PP 09.36

THE ~'~w%CT OF FOOD ON THE PHARMACOKINETICS OF HP 029 IN ELDERLY MEN H. B. Lassman~ S. K. Puri~ I. He and R. Hsu HP 029 (1,2,3,4-tetrahydro-9-aminoacridin-l-ol-maleate) is a new drug undergoing Phase II clinical testing for the treatment of Alzheimer's Disease. An open-label, randomized, crossover study was done in 24 healthy elderly men to determine whether food affects the pharmaeokineties of a single oral 100 m6 dose of HP 029. Each subject received the drug once after an 8 hour fast, and once 15 minutes after a standard breakfast. The two study periods were separated by 7 days. The concentrations of HP 029 in plasma and urine were determined b y H P L C . The mean pharmacokinetic estimates are: No Food Food Mean SD Mean SD P Cmax (ng/ml) 213 + ~ 175 + 5Y p < O.OO1 %max (h) 1.5 + 0.8 2.5 ~_ 0.8 p < 0.001 AUCo-2hh (ng/ml.h) 880 T 326 938 + h58 NS AUCo~ (ng/ml.h) 886 ~ 330 946 + 468 NS

ABSOLUTE BIOAVAILABILITY OF THE ACE INHIBITOR RAMIPRIL B. Bauer, R. Irmisch, H.-G. Eckert and D. $chmddt Ramipril is a new potent and long-acting ACE inhibitor. It is a prodrug which is converted to its active metabolite ramiprilat by the cleavage of an ester group. This crossover study investigated the absolute hioavailability of a single oral dose of 5 mg ramipril in twelve healthy male volunteers aged 21 - 44 years. The washout period between treatments was two weeks. Ramipril and ramiprilat were measured in plasma by RIA. Urine was collected for GC determination of ramipril and its metabolites. The table summarizes the main pharmaeokinetic data (mean

tl/2 Aeo-24h

(h) (rag)

Cl D Relative Bio. (%) AUC Urine

2.7 _+ 0.5 16.7 _+ 6.6

2.7 _+ 0.6 18.5 + 8 . l

285 + 9h

301 + 112

iOO iOO

105 112

---

NS p < o.o5 NS

. . . . . . . .

Administration of KP 029 with food resulted in significantly lower peak plasma levels of KP 029, delayed t~mes to reach peak plasma levels without significantly affecting AUCs and ha]/" life. The amount of m P 0 2 9 excreted in urine was slightly higher when drug was taken with food, hut renal clearance was not altered. The relative bioav&ilabilitywas essentially unchanged when dru 6 was administered with food. These results indicate that food delayed the rate hut not the extent of HP 029 absorption. Therefore, the drug can he administered with or without food. Hoeehst-Roussel Pharmaceuticals Inc., Route 202-206, P.O. 2500, Somerville, NJ 08876-1258 USA

(SO)). Cmax (ng/ml) tmax

Ramipril Ramiprilat i.v. oral i.v. oral 347.2(113.1) 16.2(10.7) 29.2(i0.i) 9.2 (5.1)

0.1

(0.0)

0.8 (0.6)

2.1 (1.0)

3.2 (2.1)

(h) AUC O-Sh (ng, h/ml) AUC 0-24h (ng.h/ml)

85.1 (28.3) 19.7(15.2) i24.1(40.9) 38.9(t8.9) 94.0 (30.2) 26.6(24.5) 173.9(48.6) 75.5(29.8)

The absolute bioavailability of the unchanged compound ramipril was 27.6 + 27.0 % (range 3.2 - 87.8 ~) based on the AUC O-8h values. The relative bioavailability of the bioactive metabolite ramiprilat after oral administration of ramipril compared to intravenous administration of ramipril was 44.2 + 1 5 . 1 % (range 20.2 - 70.2 %) based on the AUC 0-24h values. A relative bioavailability of 78.6 ! 3 1 . 1 % was calculated from the total urinary recovery of ramdpril and metabolites. The contribution of the different substances to the urinary excretion was different for oral and intravenous administration. The total urinary recovery after intravenous administration was 80.9 + 21.9 % of the dose, indicating that other major pathways are also involved in the elimination of ramipril. Hoeehst AG, Postfach 80 03 20, D-6230 Frankfurt/M.-HSehst

PP 09.35

PP 09.37

PHARMACOKINETIC AND TRANSIT CHARACTERISTICS OF A NOVEL FORMULATION OF ERYTHROMYCIN ETHYLSUCCINATE UNDER FASTED AND FED CONDITIONS. J.G. Devane and S. Mulligan Erythromycin ethylsuccinate (EES) may be more extensively and consistently absorbed following oral administration than erythromycin base. EES is commonly used in children and for this reason is available in liquid form. While sometimes dosed b.i.d., the pharmacokinetic profile of conventional liquid forms of EES, due to its relatively short half-life of ].5-2 hours, is best suited to q.i.d, dosing. For this reason a specialised liquid formulation of EES was prepared using drug-polymer micromatrices of average particle size 50p (PharmazomeTM) in a compatible vehicle. The pharmacokinetic characteristics of this new dosage form of EES (E) was compared with a reference liquid form (R) in 24 subjects and also under fasted and fed conditions. E, under fasted conditions~ demonstrated a marked and significantly higher extent (+ 292%) and slower rate of absorption compared with R and a more extended plasma profile. When R was administered with food~ the extent of absorption was increased (+ 30.6%) but the rate of absorption was unchanged. In contrast E in the presence of food showed a reduction in extent of absorption (- 29.1%) and a delay in rate of absorption. These changes in absorption pattern with food were investigated further in a radiographic study using a barium sulphate substituted presentation of E. In contrast with the fasted state~ food resulted in a delayed gastric emptying of the bolus vehicle and consequently a slower dispersion of the microparticles in the small intestine correlating with the observed changes in blood levels. In conclusion~ the combination of pharmacokinetic and imaging techniques may prove particularly useful in characterising food effects of novel oral dosage forms. ELAN CORPORATION~ ATHLONE, IRELAND.

ABSOLUTE BIOAVAILABILITY OF DIPYBONE FILMTABLETS HG Luus, BH Meyer, FO MOiler, KJ Swart and M Badian

Dipyrone is an e f f e c t i v e analgesic, a n t i p y r e t i c and a n t i inflammatory drug. The aim of this study was to compare the bioavailability of dipyrone filmtablets given as a single dose with that after intravenous administration in twelve young healthy volunteers. Following oral administration dipyrone is extensively and almost completely hydrolysed to the metabolite 4-MAA during the first pass through the gut and/or liver. However, following intravenous application, some of the unchanged dipyrone is likely to be removed from the blood stream before hydrolysis to 4-MAA by being carried to the kidney as unchanged dipyrone where it is converted to 4-MAA and excreted in urine. This results in higher renal clearance of 4-MAA after intravenous administration during the first 2 hours after drug administration. A mathematical adjustment to compensate for the difference in renal clearance was applied before calculation of the relative bioavailability (RB) based on the AUC's of 4-MAA. The RB of 85 % (95 % confidence interval: 70 % - 103 %) is an indication that these filmtablets may be administered orally with good effect. Dept. of Pharmacology, University of the Orange Free State PO Box 339, Bloemfontein 9300, South Africa

A 241

PP 09.38

PP 09.40

EFFECTS OF CONCOMITANT FOOD ADMINISTRATION ON ABSORPTION OF GR32191, A THROMBOXANE Aa RECEPTOR BLOCKING DRUG N M Frazer, L Blake, M K Charter GR32191 is a potent thromboxane Az-receptor blocking drug producing antagonism of platelet aggregation in man (M Thomas et al., Thromb Hasmostas 58, 181~ 1987). Previous volunteer studies have been c-o~ducte= in the fasting state, and for therapeutic use it is desirable to determlne effects of concomitant food administration on the plasma drug profile. Twelve healthy male volunteers (28-37 years, 58-i07kg) received a single 80mg oral dose of GR32191 on two occasions separated by 7 days. Drug was administered with 100mls water either fasted (12 hours) or 30 minutes following ingestion of a standard meal. Blood samples were analysed using h.p.l.c with UV detection (limit of quantification 5ng/ml) for GR32191 pre-dosing and 0.25, 0.5, 0.75, i, 1.25, 1.5, 2, 2.5, 3, 4. 6, 8, i0, 12, 16, 24 hours post-doslng. Results Fasted Fed P Cma x 556n~/ml (450-686) 398ng/ml (322-492) 0.03 tma x 60 m3n (30- 75) ]35 min (ah-2a0) 0.02 6UG~(nghr/ml) 1504 (140S-1607) 1420 (1329-1517) O.19 L~ 269min (164-374) 469 min (364-574) 0.01 Cmax, AUCm and tm (means and 95% confidence intervals) were analysed b~ analysis of variance, tmax (median and range) was analysed using the procedure of Koch GG (Biometrics, 1972, 28; 577-88).

DETERMINATION OF BIOEQUIVALENCE OF ORAL TAMOXIFEN PREPARATIONS F. Plav~i6, A. Wolf-~oporda, I. Franceti6 and B. Vrhovac Determination of bioavailability of oral tamoxifen preparationa from three different manufacturers could not be conducted in healthy volunteers for some ethical reasons. Likewise, long elimination half-life of this cytostatic and small oscillations in concentrations between the doses have prevented the study to be conventionally designed. Therefore, it was conceived as a cress randomized trial in which patients were administered tamoxifen in a dose of 2xi0 rag/day during ~ days, and in a dose of 4 0 rag/day on day 15. Biological samples were taken I, 2, 3, 4, 6, 8, 12, 24, 36 a n d 4 8 h after the dose. Following tamcxifen extraction and rearrangement induced by UV irradiation, the concentration was measured by liquid chromatography using a fluorescent detector. The preparations were compared according to areas below the high dose concentration curves, the times to peak concentrations and the peak concentration values. For the reference preparation (Nolvadex, ICI), mean areas below the concentration curves were 2590 /ug x h/l, peak concentrations 197 /ug/l, and elimination half-life 79 h.

The reduction in Cmax, increase in tmax and apparent increase in t~ are all consistent with a slower rate of absorption after a meal. AUC~'s are broadly similar z however, suggesting a similar extent of absorptlon in both the fed and fasted states.

Institute of Clinical Laboratory Diagnostics, Zagreb University School of Medicine, Clinical Hospital Center, Ki~patiBeva 12, YU-4 I000 Zagreb, Yugoslavia

Glaxo group Research, Ware, Herts., UK.

PP 09.39

PP 09.41

BIOAVAILABILITY O F A N E W - S L O W RELEASE POTASSIUM CHLORIDE TABLET VS TWO R E F E R E N C E F O R M U L A T I O N S IN NORMAL HEALTHY VOLUNTEERS AFTER SINGLF ADMINISTRATION J.J. THEBAULT, ~. DAHAN, R. PAMPHILE, H. C A F L A I N The b i o a v a i l a b i l i t y of a n e w - s l o w release potassium "chloride tablet (micro e n c a p s u l a t e d formu-lation : MET) was c o m p a r e d with two reference formulations potassium chloride solution (PS) and wax-matrix tablet (WMT) by m e a s u r i n g the potassium u r i n a r y excretion. Twelve h e a l t h y male volunteers were given in a simple blind placebo controlled, randomized c r o s s - o v e r study 8 MET BOO mg tablets 64.8 mmol K+, 67.5 mmol K+ of 5 MET 1000 mg tablets, 67.5 mmol K+ of 67.5 ml PS or placebo with one week interval. A proper control of diet ( p o t a s s i u m supply), fluid intake, physical activity and urine collection was realized d u r i n g each sequence. Basal excretion of p o t a s s i u m e v a l u a t e d in the 48 hours p r e c e d i n g each administration was similar in the four sequences. The three p o t a s s i u m f o r m u l a t i o n s (MET, WMT, PS) have an e x c e l l e n t b i o a v a i l a b i l i t y about 80%. Bioavailability of WMT and MET is not sigsificantly different from PS. The slow release characteristics of MET and WMT are confirmed by the fact that p o t a s s i u m excretion is s i g n i f i c a n t l y d i f f e r e n t from PS (lower durin z the first 4 hours and higher d u r i n g the following 8 hours). The e x c e l l e n t b i o a v a J l a b i l i t y of both slow r e l e a s e f o r m u l a t i o n s ( M E T a n d WMT) as compared to PS, might indicate that potassium absorption is s i m i l a r in the s t o m a c h as in more distant portions of the gut. In view of the comparable pharmacokinetic p a r a m e t e r s of these MET and WMT formulations, the choice between them has to be done c o n s i d e r i n g their r e s p e c t i v e safety p r o f i l e w h i c h w o u l d require further large e p i d e m i o l o g i c a ] studies. Institut ASTER, 15 rue Eug4ne Miilon 75015 ~AEIS

DETEBMINATION OF CEPHALEXINE ABSORPTION FROM TWO DIFFERENT PRODUCTS (TABLETS 500 mg) USING NEW DECONVOLUTION METHOD I. Franceti6, V. Jovanovid, F. Plav~i6, B. Vrhovac New deconvolution method was used to determine absorption of peroraly administered 500 mg tablets, two different brands of cephalexin without reference to iv data. Ten healthy volonteers participated in the study. DEKONV computer program based on trapezoidal nt~nerical method was applied. The absorption is expressed to I L volumen of central compartment. The aim of the study was to evalucre the absorption of cephalexin measured by deconvolution method in comparison to absorption estimated by urinary excretion, since cephalexin is ~ 95% excreted unchanged by urine. The results analysed by multiple linear regression method showed that absorption measured by new deconvolution method highly correlates to the absorption estimated by urinary excretion as well as to the volume of central compartment. Forementioned high correlation was found for both brands of cephalexin. By deconvolution method used in this study the rate of absorption was determined as well. This provides a new parametar for assessment of bioavailability of perorally given drugs. National ADR Centre, Section of Clin.Pharmacol., Dept. of Medicine, University Hospital Rebro, Ki~pati6eva 12, 41000 Zagreb, Yugoslavia

A 242

PP 09.42

PP 09.44

TME EFFECTS OF LONG-TERM STORAGE AND OF FOOD INTAKE ON TEE RITODRINE BIOAVAILABILITY FROM SUSTAINED-RELEASE CAPSULES AT STEADY STATE F.Ebes, M.Raghoebar, H.Roseboom

R E L A T I V E B I O A V A I L A B I L I T Y OF ( • A D M I N I S T E R E D IN T A B L E T S A N D C H E W I N G

Ritodrlne hydrochlorlde is a betasympathomimetie drug used in pro-term labour. A sustained-release formulation (ritodrlne-SR) has been developed which allows a convenient dosing frequency of 3 times daily, resulting in an increased clinical applicability of oral ritodrine. Storage of ritodrine-SR at moderate and stress conditions leads to changed in-vitro dissolution. We studied the effects of altered dissolution and of food intake on bioavailability from ritodrine-SR capsules. Four treatments, each lasting for 4 days were given in a cross-over study to 24 non-pregnant females, with no wash-out period between treatments. The treatments (40 mg t.i.d) were fresh capsules as reference(R), the same capsules with a high fat, high calorie breakfast(B), aged capsules(A) and old capsules(O). Blood was sampled over 8 hours after the last dose of each treatment; plasma was assayed by HPLC with ECD. Statistical analysis compared the test treatments to R by means of ratio with 90~ confidence limits. The mean AUCs for treatments R, B, A and 0 were 92.7, 88.1, 95.6, and 99.6 ng.h/ml. The ratios of AUC B/R, A/R, and 0/R were 0.95, 1.03, and 1.07 with 90% confidence limits of 0.84-1.08, 0.91-1.17 and 0.94-1.22. Similar results were found for Cmax values. The test treatments were bioequivalent to R with a tolerance of 22% at the 5X level of significance. We conclude that food intake and storage under moderate and stress conditions of ritodrine sustained release have no influence on the oral bioavailability.

V e r a p a m i l is an a n t i a r r h y t m i c a n d a n t i a n g i a l drug which selectively inhibits membrane transp o r t of c a l c i u m . A l t h r o u g h v e r a p a m i l is a l m o s t c o m p l e t e l y abs o r b e d f o l l o w i n g p e r o r a l a d m i n i s t r a t i o n the b i o availabilty is low d u e to e x t e n s i v e " f i r s t pass" elimination. Furthermore the bioavailability shows large i n t e r - a n d i n t r a i n d i v i d u a l v a r i a t i o n s d u e to c h a n g e s in first p a s s m e t a b o l i s m if the p e r o r a l k i n e t i c s a n d b i o a v a i l a b i l i t y are s t u d i e d on s e p a r a t e o c c a s i o n s . As a r e s u l t of the l o w b i o a v a l a b i l i t y f o l l o w i n g p e r o r a l a d m i n i s t r a t i o n a l t e r n a t i v e r o u t e s of a d m i n i s t r a t i o n h a v e b e e n sought. T h e a b s o r p t i o n of ( • administered o r a l l y in c h e w i n g g u m is d o s e s of 2 3 . 4 - 2 9 . 7 m g w a s c o m p a r e d w i t h 80 m g of ( • given p e r o r a l l y as t a b l e t s in s e v e n h e a l t h y v o l u n t e e r s in a s t u d y u s i n g a o p e n b a l a n c e d c r o s s over design. Following peroral administration the m e a n • SD A U C / D w a s (5.4• x 10 -3 h r / l a n d a f t e r a d m i n i s t r a t i o n of c h e w i n g g u m (6.6• x 10 -3 hr/l. The AUC ratio of verapamil:norverapamil was higher after oral than after peroral administration, i n d i c a t i n g t h a t a p a r t of the v e r a p a m i l a d m i n i s t e r e d in c h e w i n g g u m w a s a b s o r b e d t h r o u g h the o r a l m u c o s a .

Duphar B.V., Drug Disposition 1380 AA Weesp, The Netherlands.

D e p a r t m e n t of P h a r m a c e u t i c s , R o y a l of P h a r m a c y , 2 U n i v e r s i t e t s p a r k e n , C o p e n h a g e n ~.

Department,

P.0.Box 2,

PP 09.43 BIOAVAILABILITY OF ADMINISTERED DOSE G. Bianchetti,

L.L. M.R.

Christrup, Rassinq

J. Bonde,

S.N.

GUM

Rasmussen

&

Danish School DK 2100

PP 09.45 DILTIAZEM

AS

A

FUNCTION

OF

THE

M. Regazzi* and V. Ascalone

Diltiazem (DTZ) is a calcium entry blocker widely used for the treatment of stable angina and hypertension. Previous studies have shown that DTZ undergoes an important first pass effect and that the extrapolation from single administration to repeated administration underestimates plasma concentration values. Such a finding could be explained by a saturable first pass effect. In order to validate this hypothesis, 4 single doses of diltiazem (i0, 20, 40 and 120 mg), formulated as a capsule containing the drug without any other excipient, were administered at one week interval to 8 healthy volunteers. Blood samples were collected over a 24 hours period. The results : a) Interindividual variability was highest at the lowest dose and lowest at the highest dose. b) Bioavailability was almost nil after i0 mg in 3 over 8 subjects after the administration of the 10 mg dose. c) The mean bioavailability increased with the dose from 11.8 + 2.5 % after i0 mg, to 28.2 % after 120 mg. d) Elimina~ion half-life was not dose-related, e) Renal excretion of DTZ increased with the administered dose from 1.0 + 0.3 % after I0 mg to 3.0 + 0.5 % after 120 mg. These [esults are in agreement with a partially saturable first pass effect for DTZ. SYNTHELABORECHERCHE (L.E.R.S.) 23-24, av. Morane Saulnier - 92366 MEUDON-LA-FORET (F) *POLICLINIOOS. MATTEO 27100 PAVIA (I)

BIOEQUIVALENCE STUDY OF TWO DIFFERENT PREPARATIONS OF NIFEDIPINE Seanra J. Mestres M. de la Torre R. Farr~ M. U~ena B. Bi~orra J. Caml J. There are some data addressing about the non-bioequivalence of soft gelatine nifedipine capsules administered sublingually (Br J Clin Pharmacol 1987; 23: 589-590). A clinical trial was carried out to study the oral bioequivalence of two nifedipine formulations marketed in Spain by the oral route, Methods Ten healthy male volunteers participated in a randomized cross-over trial designed to compare the pharmacokinetics of two different capsules of nifedipine I0 mg. The reference compound (A) was a soft gelatine capsule containing the nifedipine as a solution. The generic conpound (B) was a hard gelatine capsule containing nifedipine as a powder. After fasting 12 h the subjects swallowed 2 capsules (20 rag) with i00 ml of water. Blood samples were drawn at 0, 0.17, 0.25, 0.33, 0.5, 0.75, I, 2, 4, 6 and 8 h. . Plasma levels of nifedipine and its nitropyridine derivative were measured by GC-electron capture detection being the sensitive limit 1 ng/ml. AUC 0-8h were calculated by the trapezoidal method, Cmax and Tmax from the experimental data. Bioequivalence was assessed by a three-way ANOVA and Westlake method (~ % > 20 %). Results AUC Cmax Tmax 0-8 h ng/ml hours Capsule A 275* 163 ~ 0.77 Capsule B 208 63 1.33 * P< 0.01 * P< 0.02 n.s. Westlake's method: A % = 35 %. The F relative was 0.76. Conclusion The two formulations studied were non-bieequivslent. Further studies are needed to assess the clinical consequences of these non-bioequivalency. Dept Pharmacol, Inst Mun Inv Med (IMIM), P. Maritim 25, 08003-Barcelona, Spain.

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PP 09.48

A STUDY OF THE ABSORPTION OF DILTIAZEM FROM DISTAL PARTS OF TIlE GASTROINTESTINAL TRACT T Ryd~n 1 , U E Jonsson 1

ABSOLUTE BIOAVAILABILITY OF CICLOPROLOL MEASURED WITH STABLE ISOTOPES J.P. Th~not, G_~ Bianchetti, A. Cournot , P.L. Morselli P. Padovani The absolute bioavailability of cicloprolol, a partial 81-adrenergic receptor agonist, was measured in 8 healthy male adults after the simultaneous ac%ninistration of intravenous 13C cicloprolol (50 mg) and oral 12C cicloproloi (one 50 mg tablet). Blood concentrations and urinary excretion of unchanged drug were followed by means of a fragmentographic assay using the 2H5 labelled drug as a marker. Following derivatization with heptafluorobutyric anhydride, ions at m/z = 508.25, 511.25 and 513.25 were monitored for the determination of cicloprolol, cicloprolol 13C and cicloprolol 2H5, respectively. Mean values of the pharmacokinetic parameters calculated from plasma and urine data are summarized in the following table.

Diltiazem is a candidate for development of an oral extended release dosage form. A prerequisite for an adequate bioavailability of the drug administered by that way, is a sufficient absorption from distal parts of the bowel. Thus the absorption characteristics of diltiazem delivered directly into the colon were investigated by using the positioned release/high frequency (HF) capsule technique {O. Schuster, B Hugemann. In: Drug Absorption at Different Regions of the Human Gastro-lntestinal Tract: Methods of Investigation and Results. N Rietbrock, B G Woodcock, A H Staib, D Loew. Braunschweig 1987:28-38). Methods: In a two-period, single dose study in 9 healthy male volunteers, 120 mg diltiazem hydrochlodde was administered as a solution orally and in the HF capsule. The capsule was released in the caecum in 4 subjects and in the transverse colon in 5 subjects. Due to practical reasons, all subjects received the HF capsule during the first experiment followed by the oral solution 3 days later. Blood samples were drawn frequently during 12 hours after oral dosing/capsule release. Results: The pharmacokinetic variables (mean + sere) are summarized below:

Tmax (h)

I I

Variable

Oral sol

HF caps

Cma x (nmol/I)

491 4- 76

188 • 47

tma x (hours) AUC (nmol-h/I) Fre I (%)

0.6 4- 0.1 1816 4- 262 -

3.2 4- 0.7 1529 4- 294 82 • 5

P.O.

p-value <0.01 <0.05 <0.05

* Mean of the caecum and the transverse colon Conclusion: The result shows that diltiazem is absorbed throughout the gastrointestinal tract, although the absorption is more effective in the proximal region compared to the colon.

2.3 +0.5

]

Cmax TI/2 (ng/ml ) (h)

I

112 +7

I.V.

1

J n.B

J.BlZ

+0.7

+89

12.5

.

AUC F (ng/ml.h) I (%)

+i~

[

2069

"i~

C1 V (i/h/kg) I (i/kg)

l

I ~s I I +2 1

CIR (i/h/kg )

i I 1

I 0.324 I s.7 I 0,100 I +~176 I +~ I +~176

Urinary excretion data slightly overestimate the bioavailability measured by the AUC ratio (F = 91,0+1,9 % vs 88+2 %). This low first pass effect explain--the low in-terindividual variability of cicloprolol pharmacokinetic profile and suggests that pharmacokinetic interactions with cicloprolol should be limited. SYNTHELABO RECHERCHE (L.E.R.S.) 23-25, av. Morane Saulnier 92366 MEUDON-LA-FORET CEDEX (F)

1 Pharmaceutical R&D AB H&ssle, S-431 83 M61ndal

PP 09.47

PP 09.49

COMPARISON OF DISSOLUTION RATES AND BIOAVAILABILITIES OF TWO ATENOLOL TABLETS.

C O M P A R I S O N OF C R Y S T A L L I N E AND I~ICRONIZED F O R M OF P I R O X I C ~ J. Vicha~ J. ~acek, H. T o m a n k o v ~ T J. Jigincov~, J. E L I S

L Khazaeinia, ~ Mahmoudian, P. Salehian, S. Saber, M__=Bijanzadeh, L. Eshghy and A Khosravz The in-vitro d~ssolution rate and bioavailability of two atenolol preparation (tenormin 100 mg tablet ICl, U.K. and a generic atenolol i00 mg tablet, Darou -Pakhsh Co., Iran) were compared in a cross-over study in 8 non-fasting healthy volunteers. Both preparations dissolved completely (more than 90~) in less than 20 min. and showed a similar dissolution profiles. Atenoiol peak level is reached 3.04 +.61 h. after tenormin and 2.61+.42 h. after generic tablet administration. The Cp maximums were also comparable (336.3+142 ng/m] for tenormin and 337.9+50 ng/ml for Generic tablet). The AUC-> 12 is also comparable in two tablets (2262 +251 ng/ml/h for tenormin and 2421 + 289 ng/ml/h for generic preparation). It is also observed that the mean plasma concentration vs time curves of both preparation can be superimposed. It is concluded that these two preparation have similar bioavailability and therefore, the dissolution profile of atenolol preparation can be used as a good criteria for the prediction of its bioavailability. Pharmacokinetics Lab., Pharm. Reg. Ctr., Darou-Pakhsh Co., P.O. Box 13185-877, Tehran, IRAN

P i r o x i c a m cps. (10 mg) p r e p a r a t i o n s made e i t h e r f r o m c r y s t a l l i n e or m i c r o n i z e d s u b s t a n c e were compared. p h a r m a c o k i n e ~ i c p a r a m e t e r s of P i r o x i c a m p r e p a red f r o m m i c r o n i z e d substance were f o u n d to be p r a c t i c a l l y the same w h e n c o m p a r e d to the corr e s p o n d i n g p a r a m e t e r s of F e l d e n c p s . p r e p a r a tion. The use of crystalline substance for Pir o x i c a m p r e p a r a t i o n r e s u l t e d in a d e c r e a s e of a b s o r p t i o n rate w h i c h h o w e v e r was s t a t i s t i c a l l y not s i g n i f i c a n t in the f o l l o w e d v o l u n t e e r s group. Other p h a r m a c o k i n e t i c p a r a m e t e r s of Pir o x i c a m p r e p a r e d f r o m c r y s t a l l i n e s u b s t a n c e did not d i f f e r f r o m those of b o t h other p r e p a r a tions under study. The in vitro r e l e a s e of the active c o m p o n e n t into the a r t i f i c i a l gastric juice f r o m m i c r o nized substance c o r r e s p o n d e d well w i t h the Felden cps. p r e p a r a t i o n (Pfizer GmbH), while a slower r e l e a s e of the active c o m p o n e n t f r o m the p r o d u c t b a s e d on crystalline substance was o b served. State I n s t i t u t e for D r u g Control, ~ r o b ~ r o v a 48, 100 41 Prague 10, C z e c h o s l o v a k i a .

A 244

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PP 10.01

THE PHARMACOKINETIC EVALUATION OF THE RATE OF ABSORPTION FROM TWO CONTROLLED-RELEASE ORAL THEOPHYLLINE FORMULATIONS C. Betlach, M. Rowland, S, Toon, B. Holt, and M. Gonzalez The rate of drug absorption at steady state from a controlled-release (CR) formulation is usually evaluated from the Tmax and the percent fluctuation. This paper will examine several different methods of evaluating the flatness of the concentration-time profile from data obtained from a randomized two-way crossover study that compared a new 24-hour CR 400 mg theophylline tablet, Uni-Dur, (UD) dosed q 24 h at night compared to 400 mg Uniphyllin (UP) also dosed at night in 14 healthy non-smoking males. Doses were individualized to achieve a steady-state trough plasma theephylline level of approximately i0 #g/ml. Blood samples were collected every 2 h for 24 h on the 5th day of treatment. The methods used to evaluate the rate of theophylline absorption were Tmax, percent fluctuation, the fraction of the 24 h dosing interval between i0 to 20 ~g/ml, the peak occupancy time (POT) and the variation of 24 h plasma levels (CVCP). The mean values for these parameters are as follows: UD UP Significance Tmax (h) ii.0 10,3 NS % Fluctuation 92.5 126.3 S Fr 10-20 0.63 0.50 S POT (h) 4.30 4.06 NS CVCP (~) 27.71 45.36 S The results suggest that Tmax and POT are not sensitive enough parameters to detect differences between products. Other parameters which are easy to determine may offer more utility. Sobering-Plough Research, 50 N.W. 176th Street, Miami, FL 33169, USA and Medeval Limited, University of Manchester, Coupland III Building, Oxford Road, Manchester MI3 9PL, England.

REVERSAL OF RELATION OF SODIUM AND POTASSIUM CLEARANCES TO NATRAEMIA IN PATIENTS WITH SEVERE HEART FAILURE ON CONVENTIONAL DIURETIC THERAPY AFTER COMBINATION WITH CAPTOPRIL R. Hrdina, V. Kr@tk~ +~ D. Svoboda~ J. Bartonov@+ Fifteen patients with heart failure receiving furosamide 80 mg/ day or more and amiloride 5 mg daily and not loosing body weight for three days at least were given captopril 6.25 mg three times a day initially with gradual increasing to average daily dose 68 mg. Captopril was started not sooner than after seven days of hospital monitoring. We followed among others patient data necesw to calculate renal clearances ( CL ) o~ Na-, K ~ and creatinine and these data were related to serum natraemia. Addition of captopril to continuing furosemide therapy ( after cessation of amiloride ) led to the following changes: I. reversal os possitive correlation of natraemia to CL~ + ( r = 0.20, N.S.)to negative correlation (r = ~ . 4 2 , p
PP 09.51

PP 10.02

THE EFFECT OF CHARCOAL ON DIPYRIDAMOLE AND PHENOBARBITALE ABSORPTION IN NAN F. D onath~ U. LSffler~ G. le Petit and K. Feller The ability of activated charcoal to adsorb a wide variety of substances is well known. In vitro, the extent of adsorption depends mainly on the relative amounts of the charcoal and the substances ingested. Futhermore, the pH of the incubation medium, as well as other factors such as the quality and formulatlon of the charcoal also has an effect. 8 healthy volunteers participated in a randomised crossover trial in which phenobarbitale (0.2 gm) or dipyridamole (0.2 gm) alone or simultaneously with charcoal (I.0 or 2.0 gm) were administered orally with 140 ml tap water. Drug absorption was characterized by the peak drug concentration and by the time to reach peak concentration. In vitro the potency of charcoal to adsorb these drugs was investigated changing the pH and the charcoal drug ratio. We conclude that the activated charcoal adsorbs dipyridamole so quickly as phenobarbitale. The hight of the peak drug concentration depends on the amount of charcoal ingested. In vitro, a 10:l charcoal phenobarbital ratio resulted in complete adsorption of phenobarbital onto charcoal. A 20:I charcoal dipyridamole ratio resulted in 96% of dipyrldamole bound onto charcoal. The results in vivo and in vitro were comparised and in depending on the physicoehemical properties of drugs discussed. Institute of Clinical Pharmacology, Medical Academy Dresden, Fiedlerstr. 27, GDR 8 0 1 9 Dresden

EFFECT OF LONG-TERM ANTIHYPERTENSIVE TREATMENT WITH ENALAPRIL ON ADRENERGIC AND SEROTONER6IC SYSTEM K. ~ebekov@~ K. J u r e ~ k a v ~ M. R a u @ i n o v ~ I. Bala~ovjech~ R. Dzdrik Enalapril (Renitec, Merck-Sharp-Dohme) administered alone (14 patients, group I), or in combination with diuretics and /~-adrenergic receptor blockers (30 patients~ group II) given in dosage normalizing blood pressure was investigated for its ability to inhibit adrenergic and serotonergic system in 1 year study. Blood pressure narmaIization was achieved. Serotonin (5HT) levels in platelet rich and poor plasma decreased. Decrease in urinary excretion of epinephrine, norepinephrine and 5HT was observed. The correlation between the changes in blood pressure and inhibition of both serotonergic and adrenergic systems were found in acute phase (pretreatment values and the lStweek) in group I. In chronic effect the reduction of blood pressure correlated with inhibition of the serotonergic system in both groups. Changes in adrenergic and serotonergic systems correlated in acute phase in both groups, although during chronic treatment only in group I. It has been proved that antzhypertensive drubs with no direct adrenergic or serotonergic mechanisms of action may influence both regulatory systems. Reduction of sympathetic, and the seratonergic amplifying system activities by enalapril is important from the point of maintenance of hypertension and the development of its complications. It is concluded that a con~urrent possitive influence on adrenergic and serotonergic systems activities is an important antiatherogenic effect of enalapril. Medical Bionics Research Institute, Jed~ova 6, 833 08 Bratislava, Czechoslovakia

A 245

PP 10.05

PP 10.03 THE E F F E C T OF C A P T O P R I L AND CLON!DINE KININ SYSTEM IN H Y P E R T E N S I V E PATIENTS I. Zebrowska-~apina, M. I ~ r k i e w i c z

0N P L A S M A

B. Post~pska a n d

We have shown p r e v i o u s l y that arterial hypertension is a c c o m p a n i e d by decreased kininogenesis in plasma. In this study plasma levels of k i n i n o g e n and p r e k a l l i k r e i n were estimated in 25 hypertensive patients treated w i t h oaptopril a n d in 20 patients treated w i t h clonidine. 18 h e a l t h y subjects served as control. Both kinin system par~ameters were a s s a y e d 3 times: p r i o r to, 24 h and 21 days a f t e r captopril and: before treatment, 7 d a y s and 14 days a f t e r clonidine. It was shown that both drugs decreased plasma k i n i n o g e n a n d i n c r e a s e d prekallikrein level, w h i c h indicates indirectly the a u g m e n t e d production of kinins. These changes w e r e a c c o m p a n i e d by significant lowering of blood pressure. Our reaserohes demonstrate that the kinin system p a r t i c i p a t e s in the antihypertensive effect of captopril a n d clonidine. Department of p h a r m a c o l o g y a n d Cardiological Clinic, Medical School, jaczewskiego 8, 20-090 Lublin, P o l a n d

ANGIOTENSIN CONVERTING ENZYME INHIBITION IN THE MANAGEMENT OF PRIMARY RAYNAUD'S PHENOMENON V.F. Challenor, D.G. Waller, R.A. Hayward a M.J. Griffin and O.S. Roath The management of Raynaud's phenomenon (RP), a condition characterised by reversible digital vasospasm, remains unsatisfactory. Some vasodilators reduce both the number and severity of attacks, but up to one third of patients show no benefit. Anecdotal reports suggest that the ACE inhibitor captopril may be effective in RP, but it has also been reported to precipitate digital vasospasm. We have studied the efficacy of enalapril 20 mg once daily for four weeks in patients with primary RP. Twenty two patients (20 female) entered a double-blind placebo controlled, randomised cross-over study. Subjective response was assessed by daily records of attack frequency and severity, and rated on a visual analogue scale (VAS) and 5 point rating scale. Objective response was assessed by finger temperature rewarming times following a standardised cold water challenge. Mean attack rate was similar during treatment with placebo (6.2 • 1.2 [sem]) and enalapril (7.0 i I.I). A trend towards preference for placebo was reported for both the rating scales. Enalapril had no effect on finger rewarming times after cold challenge. Unwanted effects were reported by I0 patients during enalapril therapy, leading to withdrawal by one, and by 8 following placebo. We conclude that enalapril at a dose of 20 mg daily is ineffective in the t r e a t m e n t of primary RP and may exacerbate the condition in some patients. The study suggests that abnormal vessel sensitivity to circulating angiotemsin II plays little part in the pathogenesis of primary RP. Clinical Pharmacology Group, Centre Block, Southampton General Hospital, Southampton S09 4XY, U.K.

PP 10.04

PP 10.06

C A R D I O V A S C U L A R EFFECTS AND R E G I O N A L BLOOD ~IDW R A ~ I P R I L TRF~I~IENT iN PRi-

GLUCOSE TOLERANCE DURING CHRONIC LISINOPRIL THERAPY IN PATIENTS WITH ESSENTIAL HYPERTENSION S. UEDA, H. SHIONOIRI~ K. MINAMISAWA~ Y. ABE~ K. SUGIMOTO, A. IKEDA, E. GOTOH~ AND M. ISHII We conducted a prospective evaluation of chronic lisinopril, an angiotensin converting enzyme inhibitor, therapy on blood pressure and 75 g oral glucose tolerance following 6 month period of lisinopril administration in hypertensive patients. Six of these eleven patients exhibited impaired glucose tolerance (IGT), while the remaining five patients had normal glucose tolerance (NGT~ Lisinopril (5 - 20 mg/day) was given once a day for mean period of 9.4 months. All patients tolerated long-term lisinopril therapy, and no untoward effects were observed. Long term administration of lisinopril significantly decreased blood pressure in patients with NGT from 177.0+ 8.5/103.8+2.5 mmHg (mean + SE) to 158.4~6.7/93.6+2.4 mmHg. In patients with IGT, lisTnopril produced significant decrease in blood pressure from 165.3+1.4/99.8+1.1 mmHg to 150.0!3.4/89.3~i.i mmHg. Pulse rave did nov change in both patient groups. No patients with normal glucose tolerance developed diabetes mellitus. Neither fasting nor post-glucose-load venous plasma glucose deteriorated in any patients during chronic lisinopril therapy. There was no significant change in the insulinogenic index (AIRI/ABS at 30 min post-glucose load) in patients with normal glucose tolerance. On the other hand, slight improvement was observed in the insulinogenic index in patients with impaired glucose tolerance from 0~ to 0.23~0.06 (p<0.05). These results suggest that, in addition to its antihypertensive effects, chronic lisinopril therapy does not compromise glucose metabolism in hypertensive patients. Thus, lisinopril may have a clinical advantage in that it apparently can be given safely to hypertensive patients with either normal or impaired glucose metabolism.

BUTION DURING ~RyTRI HYPERTENSION

A~Y.Ivlev~, I.D.Antiya, N . P . S h a t k o v s k y , E.No Gavrilova," V,S ~ Molseev= V, K, L e p a k h i n S y s t e m i c and regional h e m o d y n a m i o s and cardiac s t r u c t u r a l changes were s t u d i e d in 18 p a t i e n t s w i t h m i l d to m o d e r a t e l y s e v e r e essential hyp e r t e r ~ i o n b e f o r e and t h e n 240 minutes and 12 weeks a f t e r a d m i n i s t r a t i o n of ramiprilo N e a n a r t e r i a l p r e s s u r e was r e d u c e d from 114 m m H g to 96 m m H g (p<0, O01), and this was mediated t h r o u g h a fall in total p e r i p h e r a l res i s t a n c e f r o m 36+--2 uzlits to 20+2 unlts(p
YOKOHAMA CITY UNIVEESZTY, YOKOHAMA 232 JAPAN

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PP 10.09

COMPARATIVE EFFICACY OF LISINOPRIL AND BENDROFLUAZIDE IN ESSENTIAL HYPERTENSION O. S i l a s ' . I . James'. M. Benaim', R. Brown'. A. Davies i, D. Lawrie ~, C. Melnick~ A. Gowers2,

THE BLOOD TEST

EFFECT OF CAPTOPRIL PRESSURE AND HEART IN HYPERTENSIVES

AND ATENOLOL ON RATE DURING EXERCISE

H.Kurihara,F.Ohtu,T.Suzuki,K.Tanaka,Y.Koh, Y.Hariya,K.Nagasawa,H.Kishida,H.Hayakawa

The antihypertensive efficacy and t o l e r a b i l i t y of the ACE ~nhibitor, lisinopr~l, and the diuretic, bendrofluazide, were compared in the treatment of 146 patients with all grades of essential hypertension. Patients aged 18 years or over with sitting diastolic BP ! 95mmHg were entered into a double blind, parallel group study. After 2 weeks on placebo, patients were randomised to 8 weeks treatment with lisinopril lOmg (n=74) or bendrofluazide 2.5mg (n=72) once daily. The doses were titrated to a maximum of lisinopril 40mg or bendrofluazide lOmg daily i f sitting diastolic BP > 90mmHg. The two groups were well matched for i n i t l a l BP (sitting 176/105 (22.9/8.8) mmHg v ]71/105 (23.2/B.4)mmHg, lisinopril v bendrofluazide respectively). The reduction in sitting BP was 22/13 + 15.8/I0.0 in the l i s i n o p r i l group (n =, 7Q) and 19/lO + 17.6/8.6 in the bendrofluazide group (n = 64). Thesechanges and similar changes for standlng BP were highly significant compared to baseline (p < O.OOl). The reduction in sitting diastolic BP was significantly greater in the lisinopril group than in the bendrofluazide group (p < 0.05). Twelve patients did not complete the study, 4 in the lisinoprll group (3 adverse events, I poor BP control) and 8 in the bendrofluazide group (3 adverse events, l poor BP control, 4 non attendees). Results of this comparative study in hypertensive patients indicate that short term treatment wlth lisinopril is as effective and well tolerated as bendrofluazide. ' Lisinopril Study Group ' Medical Dept. Merck Sharp & Dohme Hoddesdon Herts UK

PP 10.08 A COMPARISON OF THE FIRST DOSE BLOOD PRESSURE RESPONSE OF LISINOPRIL AND ENALAPRIL J. Garnham', S__=.Garnham~, R. Blackwood', M. Raj 2 3. O'Donnell', M. Sarjudeen', S. Davies 2, and The blood pressure (BP) response to the f i r s t dose of l i s i n o p r i l (L) and enalapril (E) was measured over 0 - 12 hrs in 44 patients with essential hypertension. Patients with a s i t t i n g d i a s t o l i c BP I 95 mmHg were entered into a double blind parallel group study. A f t e r 2 weeks on placebo, patients were randomized to receive L ]Omg (n : 22) or E Bmg in : 22). Mean BP was higher in the L group at baseline ( s i t t i n g 184/108 mmHg v 171/104 mmHg, standing 186/110 mmHg v 173/106 mmHg, L v E respectively). Both groups showed a s i g n i f i c a n t reduction in s i t t i n g and standing BP over 12 hrs compared to baseline (p
H.Okumura We

compared

the

hemodynamic

responses

of

captopril and atenolol to the supine bicycle ergnmeter exercise test(EX). Nineteen patients with essential hypertension were classified into 3 groups; Group I (6 patients, 51 9 I0 years, medicated with inactive placebo for 2 weeks). Group ~ (7 patients, 55~7years, with captopril 37.bmg daily for 2 weeks) and Group ]l[ ( 6 patients, 45 x 8 years, with atenolol 50mS daily for 2 weeks). EX was performed before and at the end of the treatment period. After

medication

before blood and HR

EX decreased in all groups, but diastolic pressure(dBP) decreased only in Group~ decreased only in Group ~ (p< 0.05,

respectively). sBF was smaller to in

systolic

During in Group

that in Group all groups. HR

blood

EX ~

the increase in and G r o u p 3~_ c o m p a r e d

~ and dBP was decrease

before and during EX. It is concluded that hypertensive drugs

the to

and EX will be clinically antihypertensive drugs essential hypertension. Department of Internal Hospital Nippon Medical Tama, Tokyo 206 Japan

pressure(sBP)

did not change only in Group~

responses EX were

of antidifferent

useful for selecting in patients with

Medicine, Tame School. I~7--i

Nagayama Nagayama,

PP 10.10 THE EFFECT OF ATRIAL ~ATRIURETIC

PEPTIDE ON THE SYSTEMIC

RENAL HE~ODYNAMICS. A. Nakatani, H. Nonaka, M. SaiCoh, K. Hayashi, N. Shiomi, A. Ueda, Y. Morita, Y. Morioka, A. K~mimoto, N. Tsujimoto, K. Yoshimura, K. Ban, K. Soda, K. Okada and H. Ishikawa Purpose: The effect of alpha-human atrial natriuretie peptide (alphahARP) on the systemic and renal hemodynamies was studied. Method: Anesthetized dogs were given a single intravenous dose of alphahANP (0.i, 0.5 or 2.5 ~g/kg). In these animals, the following parameters were determined before and after treatment: heart rate (HR), cardiac output (CO), aortic blood pressure (ABP), total peripheral resistance (TPR), pulmonary arterial pressure (PAP), renal arterial blood flow (RBF), renal arterial pressure (RBP), renal vascular resistance (RVR), cervical arterial blood flow (CBF), femoral arterial blood flow (FBF) and urine volume (UV). Results: For the 2.5 ~g/kg dose group, the HR tended to increase, the CO showed a transient small increase followed by a tendency to decrease, the ABp showed a decrease, and the TPR showed a transient decrease followed by gradual increase to the baseline level. The PAP slightly decreased following a 0.5 or 2.5 Bg/kg dose. For a low dose (O.i ~g/kg), the RBF first decreased and then tended tc increase to the baseline level, while for the higher dose group (0,5 and 2.5 ~g/kg), this parameter first increased and ~hen.decressed. For all dose groups, the RBP decreased. For the 0.i ~g/kg dose group, the RVR first increased and then tended to decrease to the baseline level, while for che 0.5 and 2.5 ~g/kg groups, the parameter first decreased and then increased te the baseline level. For the 0.5 and 2.5 ~g/ kg groups, the CBF first increased and then showed a tendency to decrease to the baseline level. The FBF decreased for the 2.5 ~g/kg group. The UV showed a two-fold increase compared to the pro-treatment level. Discussion: In the present study, treatment with ANP resulted in a reduction of C0. although this agent is known to dilate the resistance blood vessels. This finding sugests that ANP can reduce venous return. This effect of ANP is probably attributable to its natriuretic action. At the same time, however, it is possible that this agent dilates the capacitance vessels. Regarding the effect of ANP on the kidney, a 0.1 ~g/kg dose of the agent caused m contraction of the renal blood vessels and a resultant reduction of the renal blood flow in the sarly stages after treatment. For the 0.5 and 2.5 ~g/kg dose groups, however, the same aKent caused a dilation of ~he renal blood vessels and a resultant increase of 9en&l blood flow in the early stages after treatment, although the renal blood flow decreased thereafter. These findings suggest that the effects of ANP on renal blood vessels vary according to its dose level. Conclusion: i) The intensity of ANP's vasodilative action differs betwwen various organs and between various dose levels. 2) The diuretic action of ANP does not seem to depend on the renal blood flow only. The First Department of Internal Medicine of Nara Medical University, 840 Shijyocho, Kashiwara City, Nara, Japan.

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PP 10.11 THE EFFECTE OF a-HUMAN ANP ON THE RENAL CIRCULATION DOGS M. Saitoh, M. Nonaka, A. Made, A. Nakatanl, K, Hayashi and BJ Ishlkawa.

Y. Morlta,

IN ANESTHETIZED

K. Yoshimura,

K. Hoda,

Purpose: The reports on the effects of alpha human atrial natriuretic polypeptide (e-hANP) on renal microcirculation are rare. Therefore we report on the effects of systemic ~-hANP treatment on the renal cortical blood flow which was studied By determining the Blood flow in the outer and inner cortical layer of the kidney at different dose levels. Method: Under intraperitoneal anesthesia with pentoharBital and mechanically controlled ventilation, left kidney and the left ureter were exposed taking care so as not to injure the renal nerves. The ureter was catheterized for determination of urine volume and urinary electrolytes. In additlon, the renal capsule was freed, and electrodes of an electrolytic tissue blood flow meter were inserted into the inner and outer cortical layers of the left kidney. After stabilizatiom of hemodynamics, a-hANPwas intravenously i~jeeted (a 0.i or 2.5 ~E/kg dose). Blood f l ~ in the inner and outer cortical layers ~ere determined before and after G-hANP treatment. Results: After a 0.1 ~g/kg @-hANP dose, no significant change of blood flow was seen in the inmer or outer layer. After a 2.5 wg/kg dose, blood flow decreased significantly in both layers. Urine volume showed a sigaifiean~ increase after treatment with a-hANP. In analysis of urine electrolytes, sodium amd chloride showed a dose-dependent increase, while the ~-hANP-related change in p o t a s s i ~ d i d n o t significantly differ between the two dose groups. Glomerular filtratlo~ rate increased s/~nlflaantly after ~-hANP treatment. Discussion: The effect of e-hA~P on the renal cortical blood flow differed according to its dose levels. This dose~deparnde~t difference in the effect of ~-hANP on the renal cortical blood flow seems to he explained by: (i) the efferent glomerular arteriole contracts after a massive ~-hANP treatment (not after a small dose treatment), resulting in an elevation of filtration pressure; or (2) =he mesanglal cells contract after a mmssive ~-hANP treatment, resulting in a change in filtration coefficient. Conclusion: ~-hAN~was found to change the renal cortical blood flow at a high dose level and to elevate the urine volume and urinary sodium and chloride ellmi~ation in a dose-depende~t fashion. Taking into consideration the reduced blood flow in the renal cortex following a massive a-hANF treatment, it seems unlikely that the diuretic effect of this agent is due to its action to increase the renal cortical blood flow. The First Depart]ment of Internal Medicine of Nara Medical University, 840 ghijyoeho. Kashiwara City, Rare, Japan.

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PP 10.14

THE EFFECT OF ALPHA-hANP ON THE RENAL CIRCULATION Y, Morita, H. Nonaka, A. Ueda, K. Yoshimura, K. Eayashi a n d H . Ishikawa

THE CLINICAL ASPECTS OF CARDIOTONICS' BIOCHEMICAL PHARMACOLOGY I. S. Chekman~ N. A. Gorchakova and A. I. Grinevlch T h e ~ r d i a c vascular deseases occupy the leading place among the reasons of population mortalyti and imvalidity. The rise cardiac vascular pathology treatment is the important problem of the modern science. In the present work it was studied the cardiotropic agents (cardiac glycosides, the derivatives of the native metabolites) in the plan of their influence on the kreatinphosphokinase,nicotinamide,adenylate systems in the condition of the cardiac-vascular insufficiency. Digoxin,strophantine~the derivatives of the native metabolites normalize the level of the oxydate forms of nicotinamide coenzymes~creatinphosphate,ATP, activity of the creatinephosphokinase,the level of macroerges. The combine apply of cardiac glycosides with the methabollte drugs decrease the cardiac glycosides toxicity,optimize their i~otropic activity and cardiotrophic action. The experimentally established facts of glycosides therapy optimization by the metabolic drugs is theoretical elaboration for the clinical use of cardiac glycosides with the medicaments of that group. Kiev Medical Institute,Dept.of Pharmacol.& Clin.Pharmacology,Bulv.T.Schevchenko,~3, 252004,Kiev,USSR.

IN NYFERTENSIVE DOGS

K. Moda, A. Nakatani,

M. Saitoh,

Purpose: The effect of alpha-hANP (alpha-human% atrial natriuretir polypeptide) on hemodynamics and the renal circulation was explored in dogs with experimentally induced renovaseular hypertension. Methods: In 6 anesthetized dogs, the right renal artery was stenosed. One week later, electrodes of an electrolytic tissue blood flow meter were inserted into the i=ner and outer cortical layers of the left kidney. In addition, a Swan-Ganz catheter and a catheter for arterial blood determination were inserted into the pulmonary artery and the origin of the aorta, respectively. After stabilization of hemodynamics, alpha-hANP was injected via the cubital vein into the animals (a 0.1 ~g/kg dose in 3 animals and a 2.5 ~g/kg dose in the other 3 animals). The following parameters were determined before and after treatment: heart rate (MR), cardiac output (CO), aortic blood pressure (ABP), total peripheral resistance (TPR), pulmonary arterial pressure (PAP), renal inner cortical blood flow (ICBF), renal outer cortical blood flow (OOEF), urine volume (UV), urinary sodium (UNa), glomerular filtration rate (GFR), effective re~al blood flow (EEBF), plasma renin activity (PRA) and blood aldosterone level (ALD). Results: After treatment with alpha-hA~P, the CO tended to decrease in the low dose group, while in the high dose group it showed a transient increase followed by a long-lasting sigaificant decrease. The ABP significantly decreased after treatment in both th~ low and high dose groups, although the degree of change was larger in the high dose group. The OCBF increased in both dose groups, while ICBF and ERBP showed a tendency to increase only in the high dose group. The UV, UNa and GFR increased in both groups, although the degree of change was larger in the high dose group. The PRA and hloodALD level showed no reduction in the low dose group, but they decreased significantly in the high dose group. Eonelusion: The reduction of ABF following massive ANP treatment is much greater in hypertensive dogs tha~ in normal mongreal dogs. In hypertensive groups, the renal cortical blood flow increase effectively, otherwise in normotensive groups. The increase of CBF after massive dose treatment se@ms to he associated with reduced PRA. The First Department of Internal Medicine of Nara Medical University, 84D Shijyocho, Kashlwara City, Nara, Japan.

CARDIAC GLYCOSIDES:THE POSITIVE AND NEGATIVE ASPECTS OF APPLICATION A. I. Grinevich and N. A. Gorchakova ~ardlac glycosiaes are con~a!nlng in different species of Digitalis,Strophantus Kombe and gratus,Adonis vernalis, Convallariae majalis,Nevium Oleander. The e~erilence of several years glycosides' studies in experimental laboratories and apply in clinical practice allow to distinguish positive and negative aspects of that drugs' use. The cardiac glycosides'ability to realize the positive inotropic effect in the conditions in vivo and in vitro and to improve the trophic and haemodinamic effects is unique. It was shown the cardiac glycosides property to form functional complexes with biometals and bioligands on the physico-chemical level. It was established the cardiac glycosides ability to normalize the main biochemical indexes (the content of adenyl nucleotides,nicotinamide coenzymes,cytichrome P-#50 and others). At the same time the cardiac glycosides possess the limited therapeutic Width,cumulative properties,toxicit~ The intoxication is displayed by the cardiac and extracardiac symptoms (extrasystols,atrioventricular block,ventricular glimmer),the vislon and mentality disturbanses.In experimental conditions the cardiac glycosides application in toxic doses cause the undesireble boichemical functional changes in the animals'organs.So,the cardiac glycosides are Valuable drugs'group for the cure of cardiac insufficiency. But the l o w therapeutic width refracterity phenomen,toxicity and limited vegetable raw material for the glycosides production the modern science at the search of effective nonglycoside cardiotonics. Kiev Medical Institute,Dept.of Pharmacol.& Clin. Pharmacol.,Bulv.T.Schevchenko,15, Kiev,252004, USSR

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PP 10.15 THE INCREASE OF CARDIOSTEROIDS E F F E C T I V I T Y BY ~IEANS A M I N O A C I D S DERIVATIVES N. A. Gorchakova and A. I. Grinevich The"discovery p h a r m a c o l o g i s t s and cardiologists the metabolic drugs signifies not o n l y n e w opp o r t u n i t y of pharmacologic influence on contractile myocardial ability but also promotes the search of n e w that compounds combinations with cardiosteroids. On the bases of the b i o c h e m i c a l experiments it was shown b]~e more n o r m a l i z i n g influence of d i g o x i n and strophantine with d e r ~ vatives of glutamic,aspsragine acids,triptophane and cysteine on the content of n i c o t i n a m i d e coenzymes,adenyl n u c l e o t i d e s , c r e a t i n p h o s p h a t e and creatinphosphokinase' activity in the myocardium and liver of rats and rabbits d u r i n g the cardiac i n s u f f i c i e n c y and haemic hypoxia. It was established the effect of combinations on rabbits' systemic haemodinamic exponemts at haemic hypoxia in the conditions of regimen of choice was made on the basic of p h i s i c o - c h e m i c ~ experiments b y stadin@ the functional constants of stabilyty with the derivatives of a m i n o a c i d a The m e t h o d o l o g y of search optimal cardiosteroids' combinations includes the p a r t i c u l a r i t y their b i o c h e m i c a l , p h y s l c o - c h e m i c a l and p h y s i o l o gical m e c h a n i s m s of action. K i e v Medical Instutute,Dept.of P h a r m a c o l . & Clin. Pharmacol.,Bulv.T.Schevchenko,!3,Kiev,252004, USSR

PP 10.17 TREATMENT OF HUMAN COLONIC CANTER CELL5 WITH ANTICANCER

DRUGS INCREASED POLYAMINE CATABOLISM. C.S. Coleman and H.M. Wallace The polyamines are natural growth promoting factors in all cells. Intracellular concentrations are strictly regulated via omnithine decarbexylsse and polyamine acetyltransferase (PAT), the rate-limiting enzymes for biosynthesis and catabolism respectively. When the growth rate of the cell is decreased, polysmines are no longer required in high concentrations and so must be 'lost' from the cell either by metabolism or excretion. In the present study we have examined the effect of two growth inhibitory anticancer drugs on the rate of cell growth and polyamine breakdown (i.e. on the activity of PAT) in human colonic cancer cells. HT29/219 ceils are a line of human colonic careinoma cells which grow in monolayer culture at 37~ in an atmosphere of CO2/air (I/19). Methylglyoxal bis(guanylhydrazone) [MGBG] is an anti-leukasmic agent currently under clinical reevaluation. Methotrexate (MTX) is a folahe antagonist used as general cytotoxic agent both in mono-and combination chemotherapy. Beth drugs added alone or the appropriate vehicle were added to the cells at Oh. Cell growth was measured as the change in protein content with Lime and polyamines were quantified by hplc. Both MGBG and MTX inhibited ceil growth and decreased the total intraeellular polyamine eonteot over a time course of 120h in cuiture. In control eelis PAT activity decreased from 0-120h while in both MGBG and MT• cells PAT activity was maintained from 24h at about 1.5-2.0 times that in control cells indicating polyamine breakdown was increased in these cells where cell growth was decreased. These results support the hypothesis that poiyamines are only required by rapidly growing cells, and we propose that any drug-induced cytostasis, regardless of the mechanism, will decrease intracellular polyamine concentrations via increased PAT activity. Clinical Pharmacology Unit, Department of Medicine& TheFao. &Pharmacolc~y~ University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen AB9 2ZD

PP 10.16

PP 10.18

THE E F F E C T OF O,P'-DDD ON 0 X I D A T I O N - R E D U C T I O N P R O C E S S E S IN ORGANS A N D TISSUES OF W A R M - B L O O D E D ANIMALS S. V. Kandul~ A. I .Grinevich and M. I. Y a t s ~ k The purpose of this w o r k Was to study the ef~kt of o,p'-dichlorodiphenyldic]~loroethane (o,p'DDD), an effective p h a r m a c o l o g i c a l product blocking adrenocortical f u n c t l o n , o n oxidation-red u c t i o n process in the dog and rat organs and tissues. By means of the electron p a r a m a g n e t i c resonance (EPR) m e t h o d it was established that o,p'-DDD imhibited cytochrome P-450 and adrenodoxine in the dog adrenocortical m i t o c h o n d ria,but this i n h i b i t i n g ac~on was not observed in adrenals of the rat. At the same time in the rat and dog liver the cytochrome P-A50 system Was activatedx In the rat and dog p l a s m a the content o f C u Z + - c e r u l o p l a s m i n , o n e of the organism's antioxidant p r o t e c t i o n components,was increased. In the dog adrenals and testes the content of m i ~ o c h o n d r i a l flavoproteins in free radical semiquinone form was decreased. In the rat the analogous effect was not observed. The d a t a obtained b y means of the E P R m e t o d helped to establisd h e y aspects of m e c h a n i s m of the i n h i b i t i n g action on the m e t a b o l i s m in the organism, which m a y serve as a basis for the development of n e w p h a r m a c o l o g i c a l products with directed action on adrenocortical function. A l l - U n i o n S c i e n t i f i c - R e s e a r c h Institute of Hygiene and Toxicology of p e s t i c i d e s , P o l y m e r s & P l a s t i c s ; K i e v Medical Institute, G e r o e v Oboroni 6, K i e v , 2 2 5 1 2 7 , U S S R

F U N C T I O N A L E X P R E S S I O N OF ~ CYTOCHROME P 4 5 0 I A I A N D P450IA2 IN M O N K E Y K I D N E Y COS-I

CELLS M.Probst, M.Blum, A.Demierre r D.Grant and U.A.Meyer The human cytochrome P450 I gene family inducible by aromatic hydrocarbons consists of two distinct isozymes termed P450IAI and P450IA2. They are implicated in the biotransformation of clinically important drugs such as caffeine and theophylline and activate potential chemical carcinogens. The corresponding cDNAs of these two isozymes (supplied by D.Nebert and P.J.Gonzalez NIH,NCI) have been expressed in monkey kidney COS-I cells. Identity of the gene products was demonstrated by Western blot analysis using a polyclonal rabbit antiserum raised against rat P450c and P450d. The functional activity was characterized by incubating the COS cell homogenates with the two model substrates 7-ethoxyresorufin and acetanilid. The results are consistant with previous animal studies confirming high selectivity of P450IAI and P450IA2 for 7-ethoxyresorufin deethylation and acetanilid hydroxylation, respectively. These probes will be used to study the relative contribution of these two isozymes to the metabolism of different drugs and carcinogens. Biocenter of University, Department of Pharmacology, Klingelbergstr.70, CH-4056 Basel

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PP 10.21

A RATIONALAPPROACHFOR IN VITRO METABOLISMSTUDIES AN APPLICATIONWITH RP 54274 M. Martinet, B. Decouvelaere~ F. Collignon~ C. Gaillard, P. Gires, V. Piguet, J. G a i l l o t Liver microsomes are unable to Conjugate substrates. More integrated in v i t r o models as isolated hepatocytes or l i v e r slices can be advantageously replaced by the isolated and perfused l i v e r . The pool of stored cofactors allow the chemical groups to be coupled by the transfers of convenient cosubstrat. The metabolism of 14C-RP 54274, a new antiglutamate drug, has been studied in v i t r o in hepatic microsomes from various animal species and human. The isolated and perfused l i v e r of rat and rabbit have been used with a r e c i r c u l a t i n g perfusion of 14C-RP 54274. A comparison was made with in vivo studies in the rat given o r a l l y the drug (pharmacological doses). Results show that two metabolites were produced by rabbit microsomes, four by dog, mouse and human ones, f i v e by rat and nine by monkey ones. The rates of RP 54274 metabolism were increased 18 and 22 times in microsomes from phenobarbital and 3-methylcholanthrene pretreated rats respectively. Thirteen metabolites were found in the 180 minute perfusate of rat l i v e r and four in that of the r a b b i t . Nine metabolites were found in plasma from treated rats ; among them s i x were common with rat l i v e r perfusate ones and two with rat microsome ones. Seven sulfate conjugates were found in urine where they accounts for about 30 % of the dose administered. Thus microsomal RP 54274 metabolism represents only the f i r s t steps of metabolism. The isolated l i v e r shows that new pathways, probably conjugation reactions are very active. Sulfoconjugation reactions were i d e n t i f i e d in the rat in vivo and seems to correlate with perfused organ data. As compared to microsomes, isolated perfused l i v e r appears to be a useful in v i t r o model to produce both phase 2 and phase I metabolites. RhOne Poulenc Sant4 - IBP - 20, Avenue R. Aron, F-92165 Antony Cedex, France.

THE M E A S U R E M E N T OF BENZYLAMINE OXIDASE IN MITOC H O N D R I A BY A S P E C T R O P H O T O M E T R I C A S S A Y S Y S T E M DESCRIBED BY M c E w e n ET AL FOR THE HU~tAN SERUM AMINE OXIDASE S.Sho, K . S a s u ~ , K.Watanabe and Y . O m u r a The m i t o c h o n d r i a l monoamine oxidase a c t i v i t y was m e a s u r e d by the m e t h o d of M c E w e n et al., 1963. In a standard assay system using a glass bottle of 30 rmm d i a m e t e r and 50 m m height, the substrate O . O 1 M benzylamine for m o n o a m i n e oxidase was incubated at 38 ~ with 0.8 ml of 1/200 diluted hog kidney m i t o c h o n d r i a in 5 ml reaction mixture that included O . O 1 M phosphate buffer, pH 7.0, for 30 min. The reaction was sttoped by adding O.1 ml of 6N-HCI; 5 ml of cyclohexane was added and the mixture incubated for 30 min to extract the p r o d u c t benzaldehyde, w h i c h was detected by m e a s u r i n g A242 nm. By this assay system, we obtained the following results: I) A linear a c t i v i t y - r e a c t i o n time r e l a t i o n s h i p for about 3 hr was obtained. 2) The activityenzyme volume r e l a t i o n s h i p was linear from O.1 to 0.8 ml of I/2OO diluted hog kidney m i t o c h o n dria. 3) pH o p t i m u m for this enzyme using O.1 M phosphate buffer was found to be around pH 7.5, and the pS o p t i m u m for b e n z y l a m i n e as substrate was O . O 1 M . 4) The m a x i m u m activity was obtained at an incubation temperature of around 45-50 ~ This m i t o c h o n d r i a l m o n o a m i n e oxidase was strongly inhibited by pargyline w h i c h was a specific inhibitor for the B-type m o n o a m i n e oxidase.

PP 10.20

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RESPONSE OF RAT LIVER ALDEHYDE DEHYDROGENASETO TOXIC CHEMICALS AND OTHER STRESS FACTORS

THE POSSIBLE REGULATORY EFFECTS OF STEROIDS ON GLUCOSE 6-PHOSPHATE D E H Y D R O G E N A S E OF RAT LIVER. B.Haghighi, F.Vedadi Several studies have shown that some steroids including d e h y d r o p e p i a n d r o s t e r o n e (DHEA) inhibit glucose 6-phosphate d e h y d r o g e n a s e (G6PD) a c t i v i t ~ The p h y s i o l o g i c a l significance of this effect, however, needs more investigation. Disc gel electrophoresis band patterns of the liver G6PD from immature male rats showed four active bands (I, II,III,IV). In m a t u r e rats band IV was absent and band I activity decreased c o r r e s p o n d i n g to about 37% decrease observed in the total enzyme activity compared to that of the immature animals. When eleotrophoresis p e r f o r m e d in the presence of DHEA (10-4M) band IV of the i m m a f u r e rats d i s a p p e a r e d and the activity of band I for both groups was parltly inhibited with no change in bands II and III activities. A d d i t i o n of DHEA in the assay mixture inhibited G6PD activities of immature and m a t u r e animals by 67% and 52%, respectively. Digitonin treatment enhanced G6PD activity from m a t u r e rats (20%) w i t h the a p p e a r a n c e of band IV in the e l e c t r o p h o r e t i c pattern. In immuture rats, however, digitonin did not have significant effect. The differences observed in the activities and electrophorsis band patterns could be attributed to the binding of a endogenous steroid such as DHEA to the G6PD of m a t u r e rats. Biochemistry Department, Isfahan U n i v e r s i t y of Medical Sciences, Isfahan, 81744, IRAN.

M. Marselos, V. Vasiliou and M. Malamas A soluble aldehyde dehydrogenase (ALDH) (EC 1.2.1.3) of the r a t l i v e r is greatly induced by aromatic polycyclic hydrocarbons. Since the mechanism of this phenomenon is obscure, we examined whether the induction of ALDH is a nonspecific response to t o x i c stimuli of the hepatocyte. Acute i . p . treatment with known hepatotoxic agents, such as carbon t e t r a c h l o r i d e (5 mg/kg, x4), diethylnitrosamine (10 mg/kg, x4), dimethylaminoazobenzene (100 mg/kg, x4) and D-ethionine (100 mg/kg, x4), did not produce any change in the a c t i v i t y of ALDH. Also, the enzyme was not found to be affected, when measured on the 2nd and 3rd day a f t e r p a r t i a l hepatectomy, or on the 5th day a f t e r surgical cholestasis. Similarly, chemical sympathectomy (with guanethidine, 40 mg/kg, x3 weeks) did not produce any observable change. In conc|usion, the i n d u c i b i l i t y of the hepatic ALDH in the rat does not seem to be re]ated with any possible hepatotoxic properties of the effector. Department of Pharmacology, Medical School, University of loannina, loannina, Greece.

Department of Chemistry, College of Arts and Sciences, Showa University, Fujiyoshida-shi, Yamanashi 403 Japan.

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EFFECTS OF MIOFLAZINE AND ITS DERIVATIVES UPON THE BINDING OF6-(4-NITROBENZYLMERCAPTO)PURINE RIBONUCLEOSIDE (NBMPR) TO NUCLEOSIDE TRANSPORTERS IN MEMBRANES FROM HAMSTER TISSUES P. O. J. O~bunude and H. P. Baer Searching for nucleoside transport inhibitors with high potency and favorable pharmacoklnetie properties, a n d thus potential as host protectors during treatment of parasitic infections with cytotoxic nucleosides, we studied the effects of mioflazine and its derivatives soluflazine and R57974 (Janssen Pharmaceutiea) on the binding of G-3H-labelled NBMPR to lO,000xg membranes from hamster liver, lung and other tissues. Rapid eentrlfugation after 30 min incubations of cells or membranes with 1 nM 3H-NBMPR was used to separate bound from free ligand. Kd values were 2.4 (liver) and 0.44 (lung) nM; Bmax values were 3.71 (liver) and 1.04 (lung) pmol/mg protein. Binding competition curves obtained in the presence of varying concentrations of the above drugs as well as of dilazep and unlabelled NBMPR yielded inhibitor dissociation constants (Ki, ~M) as follows: NBMPR (0.0088), dilazep (0.24), mioflazine (329), soluflazine (23.9) and R57974 (0.48) in case of liver membranes. Similar orders of potency were observed with lung membranes. The rate of dissociation of 3H-NBMPR from liver membranes was strongly reduced by dilazep but not by R57974, indicating that these nucleoside transport inhibitors act via different sites or mechanisms. The most potent mioflazine derivative, R57974 was about 100-fold less potent than NBMPR or 2-fold less potent than dilazep and thus appears to be less promising than NBMPR as a nucleoside transport inhibitor in the hamster, although its pharmacokinetic and host protecting properties still remain to be investigated. Department of Biological and Medical Research, King Faisal Specialist Hospital & Research Centre, P.O. Box 3354, Riyadh 11211, Saudi Arabia

INTERACTION BETWEEN METHYLPREDNISOLONE (MTP) AND CYCLOSPORIN (CsA) ON THE HEPATIC P-450 DEPENDENT MONO-OXYGENASE ACTIVITY IN THE RAT.

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EFFECT OF TAURINE ON PREGNANCY IN RATS Abdulrahim Abu-Jayyab Department of Pharmacology, College of Pharmacy, King Saud University, P. Box 2457, Riyadh-l1451, Kingdom of Saudi Arabia The aim of this work has to evaluate the effect of taurine on pregnancy in rats including number of nidation as well as prostacycline an dthromboxane A 2 uterine levels. Four groups of rats each consisted of 7 rats. Group I served as a control receiving ordinary drinking water, group II received taurine 50 mg/kg/day, group III received taurine i00 mg/kg/day and group IV received taurine 200 mg/kg/day. Duration of treatment was 14 weeks before subjected to mating and conception. Taurine was continously given daily during pregnancy. On the 16th day of pregnancy animals were sacrificed and dissected to calculate number of faeti. The uterus also isolated, homogenized with iced Kreb's solution. To prepare the uterine 6-oxoPGF 1 and TXB 2 an organic solvent (a mixture of ethyl acetic acid; water in the ratio (v/v/v/v) Ii0 : S0 : 25 :I00) was used. The silica gel mini column was used to collect the two fractions. The prostanoids were quantitated using radioimmunoassay kits (Amersham) utilizing a high specific activity 6-oxo-PGF 1 or TXBa iodotyrosine methyl ester traces. Data were analysed using Student's t-test. The results showed that taurine decreased the faetal number in dose-dependent manner compared with the control group, concomitant with increase in uterine prostacycline level as well as decrease in thromboxane level in dosedependent manner. In conclusion, taurine might influence of infertility rate as well as an important physiological and pathological effects on reproductive mechanism.

M.E. Fracasso, G. Dal Forno, A. Conforti, R. Leone Cyclosporin has been established as a useful immunosuppressive drug in solid organ /rod bone marrow transplantation. However, several troubling reports are now emerging on metabolic interaction among Csa and many other drugs (e.g. ketoconazole, phenytoin, prednisolone, digoxin, etc.). We have investigated the mechanism of the interaction between CsA and MTP on the hepatic microsomal mono-oxygenase enzyme system. Methods: Groups of male Sprague-Dawley rats received (via the tail vein) CsA (1.5 mg/kg), MTP (0.7 mg/kg) and both drugs together, once daily, over a period of 3 days before sacrifice. The effects of the drugs on the hepatic microsomal mono-oxygenase system were determined with various metabolic parameters including: levels of microsomal protein,cyt. P-450, and cyt. b5, NADPH-cyt. c red. activity, N-demethylation of aminopyrine, and p-hydroxylation of aniline.

Results: The groups of rats treated with CsA showed a decrease compared with controls in all parameters examined; the rats treated with MTP showed an increase in all parameters except microsomal protein, cyt. b5 and NADPH-cyt. c red. activity; the group of rats treated with both drugs showed an increase of cyt. P-450, hydroxylase and demethylase activities. Values of cyt. b5 and NADPH-cyt. c red. were similar to those of the control group. Conclusion: CsA treatment exerted a toxic effect on hepatic microsomal drug metabolism in the rat reducing all considered parameters. However, combined treatment (CsA + MTP) was effective in preventing this damage. The mechanisms, behind the improvement in the hepatic drug metabolizing enzyme activity were due to the accelerated metabolism of CsA into non-toxic metabolites. Institute of Pharmacology, University of Verona, 37134 Verona, Italy.

AMINE OXIDASES IN SERUM AND TISSUES OF CANCER PATIENTS Rachel Lewinsohn The screening project involving benzylamine oxidation in normal and pathological sera, shown at CPT-86, has been continued and expanded. 20 normal and 350 pathological sere and 74 tissues from patients with benign and malignant tumours, 50 pregnancy sera and 30 solid pregnancy tissues were examined, the latter because their flavinand/or copper-dependent polyamine-oxidizing activities may be similar to those involved in malignant growth. Kinetic constants, specific activity and sensitivity towards inhibitors were studied by spectrophotometry and radio-assay respectively with unlabelled and ]4C-labelled benzylamine as substrate. Two new inhibitors, MDL72274 and MDL72527, selective for benzylamine oxidase and polyamine oxidase respectively, have been tested. Confirming results shown previously, the most significant differences between normal , pathological (ie.not close to tumour) and tumoral tissues were found in the kinetic constants of mucosa and muscle of digestive tract; specific activities and sensitivities towards inhibitors were also altered. Although at present no one parameter may suffice by itself as a cancer marker, two or three combined yield patterns that may be useful in monitoring and treating cancer patients; the most promising were found in tissues and sere of patients with oesophageal cancer. Km values of muscle, mucosa and tumour of concomitant megaoesophagus (Chagas) and cancer,compared with those of either disease alone, were significantly different. The pregnancy specimens showed MDL72274 to be a Selective inhibitor of high potential for benzylamine oxidase. Current work concerns: - the relationship between amine oxidase activities and (tumoral) angiogenesis; - increase of specificity of the assay,especially for serum; - reduction of number of steps required to process each sample; - determining the correlation between radio-assay and spectrophotometry, so as to eliminate the need for radioactive substrates. Department of Surgery, NMCE, Faculty of Medical Sciences State Univ.of Campinas,POB 6033, 13081Campinas,SP-Brazil

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METABOLISM OF PHENYTOIN BY ACTIVATED HUMAN NEUTROPHILS. L. Pawlulc D. Mavs. Z. She. W. Davis. G. ADseloff and N. Gerber. Previous studies have shown that human polymorphonuclear neutrophils (PMN) oxidize salicylate (Sagone and Husney, J. Immunol. 138:2177, 1987). This study was designed to determine whether phenytoin (DPH) could be metabolized under similar conditions. [*dC]-DPH (0.1 mM, 49/~Ci//~mol) was incubated in a medium containing purified human PMN (2x107 cells/mL). Phorbol mvristate acetate (PMA, 100 ng/mL) was added to the medium. After 1 hr, cell suspensions were centrifuged at 15,000 g for 10 min and the cell-free, unextracted supernates were analyzed by reverse phase HPLC; UV absorbance at 210 nm and radioactivity were monitored. PMN from 3 subjects produced p-, m-, and o-hydroxyphenyl phenylhydantoin (HPPH)--64-+22, 148-+51, 130_+26 pmol/mL (X_+S.E.), 70(] respectively--identified by cochromatography with authentic standards. PMN also produced unknown metabolites, several polar (1.8+0.4 nmol/mL) and one nonpolar (72-+29 pmol/mL). In controls (-PMA or -PMN) no metabolism o f DPH was detected. The data shows that 1o 2o 30 PMA, an activator of protein minutes kinase C (which ~- ~ polar p e a k s phosphorylates NADPH b,c,d,= p-,m-,O-HPPH respectively e~. unknownnonpolar peak oxidase), stimulates the ~" ~Pn biotransforrnation of DPH by human PMN. These products may contribute to the numerous adverse effects of DPH. Depts. of Pharmacology, Medicine and Family Medicine, The Ohio State University, Columbus, Ohio, 43210, USA.

HEPG2 -CELLS AS IN -VITRO MODEL FOR HEPATIC LIPID METABOLISM -EVALUATION OF CULTURE CONDITIONS. H. S c h ~ f e r , O. A u f e n a n g e r end R. K a t t e r m a n n

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PROTEIN

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Increasing knowledge about the pathogenetic relevance of hyperlipidemia lead to intensified studies on the physiological regulation and pharmacological modulation of hepatic cholesterol metabolism. Primary rat hepatocytes, being a widely used cellular test system, probably have the disadvantage of differences in lipid metabolism between rodents and man. Owing to the restricted availability of human hepatocytee our aim was to establish a standardized in-vitro test system using the human hepatoblastoma-derived cell line HepG2, known to express the major regulatory enzymes of hepatic, plasma and biliary cholesterol metabolism. HepG2 cells, routineously cultured in DMEM containing 6,1 or 25 mM glucose + 10% fcs., were plated in densities of 2• or 1,5xlO 5 cells/cm 2 representing proliferating or stationary populations during experiments. Cells were chased for lipid synthesis with 14C-acetate over 48 hrs.. Labelled lipids were extracted according to Bligh and Dyer, fractionated by TLC and evaluated using a linear analyzer. Synthesis and secretion of cholesterol was measured by LSC in the heptane phase after saponification and elution over Extrelut R . Increasing the glucose concentration in the culture medium to 25 n%M leads to a stimulation of cholesterol synthesis in stationary populations by factor 3. Addition of fetal calf serum up to 5% decreases total lipid synthesis but leads to a further increase in cholesterol synthesis and secretion, secreted lipide nearing physiological serum composition. Proliferating populations dont respond to these changes underlining the two differentiative states. Under the mentioned culture conditions HepG2 cells should be a suitable in-vitro test system for potential lipid modulating agents. Two inmkula allow to differentiate between growth inhibiting substances and agents interfering with events of lipid synthesis or lipoprotein secretion. Institut for Klinieche Cbemie, Klinikum Mannheim der Universit@t Heidelberg, D-6800 Mannheim-l, FRG.

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48

FACTORS INFLUENCING PATIENTS' UNDERSTANDING OF THEIR PRESCRIPTIONS H.Beppu, K.Abe, K.Mori and R.Hama The compliance of patients with prescriptions is influenced by various factors; these include the nature and duration of illness, the patient's level of education, living habits and the doctor-patient relationship. Correct understanding of the nature of the drugs and careful observance of prescription directions are necessary for successful treatment. Data were collected on patients selected randomly from the outpatient clinics at Fuchu General Hospital and other related hospitals. Patients were asked about drug therapy and to explain why they were taking each drug. Each drug was then checked against the patient's medical record and prescription in order to see the dose and administration period and the symptoms for which the drug was prescribed. 43 patients were interviewed and a total of 133 drug products had been given to them. 15 patients (35~) properly understood their prescriptions, while 12 patients (28~) identified drugs incorrectly, and 16 patients (~7~) didn't k~low what their drugs were for. Patients surveyed were receiving from one to six kinds of drugs, and correct understanding decreased as the number of prescriptions increased. 83 out of 133 drugs were identified correctly in this study. The duration of administration also had considerable influence on understanding. Within one month after new prescriptions, or changes of prescription, correct answers were given for only 56~ of the drugs, while between one and six months after such changes, 83% were correctly identified, suggesting an increase of knowledge with the passage of time. However, after this period, the quality of patients' answers diminished steadily. It appears that long administration periods may permit patients' attentionto lapse, and multiple prescriptions may confuse patients. Dept. Neurol., Tokyo Metropolitan Neurol. Hospital 2-O-1MusasHidai, Fuchu-shi, Tokyo 183 JAPAN

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DIC N E T W O R K - THE SWEDISH MODE~ B. 6hman, G. Alv~n, I. N i l s s o n a n d F. S j 6 q v i s t A n e t w o r k of d r u g i n f o r m a t i o n c e n t r e s (DIC) is n o w d e v e l o p i n g in Sweden. This has b e e n m a d e possible by active cooperation between clinical p h a r m a c o l o g i s t s and the N a t i o n a l C o r p o r a t i o n of Swedish Pharmacies (Apoteksbolaget). A DIC m o d e l a n d w o r k i n g m e t h o d s h a v e b e e n d e v e l o p e d at the d e p a r t m e n t of c l i n i c a l p h a r m a cology, H u d d i n g e U n i v e r s i t y Hospital. All d o c u m e n t e d q u e s t i o n s and a n s w e r s are s t o r e d in t h e d a t a b a s e D r u g l i n e w h i c h is a f u l l t e x t drug consultation database containing evaluated and p r o b l e m - o r i e n t e d d r u g information. The idea of the c o l l a b o r a t i v e p r o j e c t is to e s t a b l i s h Dies at the u n i v e r s i t y h o s p i t a l s t h r o u g h o u t the c o u n t r y a c c o r d i n g to t h e m o d e l d e v e l o p e d at H u d d i n g e and to t r a i n p h a r m a c i s t s and c l i n i c a l p h a r m a c o l o g i s t s in l i t e r a t u r e s e a r c h i n g and d r u g evaluation. All DIC will h a v e a c c e s s to D r u g l i n e and to r e d u c e the d u p l i c a t i o n of e f f o r t in a n s w e r i n g c o m p l e x q u e s t i o n s , r e p l i e s to q u e s t i o n s from all r e g i o n a l DIC will be s t o r e d in the D r u g l i n e file. So far t h r e e f u r t h e r D I C ' s h a v e b e e n e s t a b l i s h e d in S w e d e n and d o c u m e n t s from t h e s e e e n t r e s h a v e n o w b e e n i n c l u d e d in the database. The u s e of D r u g l i n e has i n c r e a s e d s t e a d i l y d u r i n g t h e y e a r s a f t e r its i n t r o d u c t i o n in 1984. W e w a n t to e m p h a s i z e two u n i q u e f e a t u r e s in this m o d e l of d r u g i n f o r m a t i o n ; the i n t e r d i s c i p l i n a r y c o o p e r a t i o n and t h e p r o d u c t i o n of e v a l u a t e d d r u g i n f o r m a t i o n , a v a i l a b l e online. T h e s y s t e m has a g r e a t p o t e n t i a l for i n t e r n a t i o n a l c o l l a b o r a t i o n b e t w e e n c e n t e r s in c l i n i c a l p h a r m a c o l o g y . Dept of C l i n i c a l P h a r m a c o l o g y , H u d d i n g e U n i v e r s i t y Hospital, S - 1 4 1 86 Huddinge, S w e d e n Natl. Corp. of S w e d i s h P h a r m a c i e s (Apoteksbolaget).

A T T I T U D E OF THE P U B L I C T O W A R D S P A C K A G E INSERTS FOR D R U G I N F O R M A T I O N IN B E L G I U M M.G. Bogaert, R. V a n d e r Stichele~ M. B r a e m and K. V a n H a e c h t B e l g i u m has a long s t a n d i n g t r a d i t i o n of o r i g i n a l d r u g d i s p e n s i n g . M o r e than 90% of the drug p a c k ages c o n t a i n a p a c k a g e insert (PI). It is a t r a n s c r i p t of the r e g i s t r a t i o n data sheet, w r i t ten in c o m p l e x t e c h n i c a l language. In June 1988 a r e p r e s e n t a t i v e sample (n=398) of the B e l g i a n p o p u l a t i o n was interviewed. 89% read the p a c k a g e in~ert and 7% leave the r e a d i n g to a n o t h e r m e m b e r of the family. 4% do not read the PI nor have it r e a d b y a n o t h e r m e m b e r of the family. M o t i v e s to read the PI (n=352) are: to be able to c o m p l y w i t h t h e r a p y (83%), to be reassured (57%), to i n c r e a s e k n o w l e d g e about the d r u g (50%) and to d e c i d e w h e t h e r or not to take the d r u g (31%). The r e a d e r s focus their a t t e n t i o n t h o r o u g h l y (as o p p o s e d to not, or o n l y superficially) to s i d e - e f f e c t s (88%), h o w to take the d r u g (85%), h o w m u c h to take (85%), c o n t r a - i n d i c a t i o n s (82%), i n d i c a t i o n s (79%), h o w long the d r u g can be kept (76%), h o w long to take the d r u g (57%), h o w the d r u g w o r k s (56%), c o m p o s i t i o n of the d r u g (39%). The i n f o r m a t i o n c o n t a i n e d in the PI was p e r c e i v e d as u s e f u l (86%) and c o m p l e t e (71%). 57% found the PI d i f f i c u l t to u n d e r s t a n d (readability), 52% found the i n f o r m a t i o n difficult to remember. 45% r e p o r t e d l e g i b i l i t y problems. R e a d i n g the PI was said to i n c r e a s e r e a s s u r a n c e (75%) and faith in the d o c t o r (75%), and not to c a u s e f e a r (69%). In 1990, w h e n all t r a d i t i o n a l p a c k a g e inserts w i l l be r e p l a c e d b y p a t i e n t - o r i e n t e d inserts, a n o t h e r s a m p l e of the B e l g i a n p o p u l a t i o n will be interviewed. H e y m a n s I n s t i t u t e of P h a r m a c o l o g y , U n i v e r s i t y Gent, De P i n t e l a a n 185, B-9000 Gent, Belgium.

of

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U S E OF C O M P U T E R S IN T H E T E A C H I N G OF CLINICAL PHARMACOLOGY E.J. Walaszek and J. Doull We have been using computer-aided instruction (CA/) for the past 18 years to teach medical students, graduate students and practicing physicians. There are some 250 separate lessons which are 20-45 rain. running time. These are divided into 4 different types: 1) self study, 2) case histories, 3) laboratory exercises and 4) review questions. In addition, we also offer examinations. Some 38 universities make use of these courses at this time. Recently we have begun a program in Clinical Pharmacology. This consists of 44 separate lessons that include some basic general pharmacology and clinically oriented lessons in Cardiovascular, Chemotherapy, Central Nervous System and Toxicology. In addition, we have a question bank in Therapeutics. At the present time, the material is used for a course in therapeutics to 200 medical students, 60 nurses who are candidates for a Master's degree, 50 anesthesiologists, and some physicians in continuing education. The entire system is supported on a mainframe IBM computer using Phoenix. Students can obtain the courses on an IBM 3270 or similar terminal or on any T r Y (via a modem). We have now transferred the entire course to microcomputers. The entire system will run on any IBM-PC or IBM-PC clone. It can be put on a hard disk and networked. We can supply the material on 5V4 or 3 89 disks. We teach Clinical Pharmacology as the eighth unit in the Pharmacology course. In addition, we teach a clinical pharmacology drug rounds for 4 weeks. This includes General Internal Medicine, Allergy and Rheumatology, Anesthesiology, Psychiatry and Pediatrics. We will demonstrate the system at the meeting and demonstration disks will be available during the Congress for distribution to interested parties. E.J. Walaszek and J. Doull. Use of computers in the teaching of pharmacology, toxicologyand therapeutics. The Physiologist28:419-421, 1985. T.L. Pazdernik and E.J. Walaszek. A computer teaching system in pharmacology for health professionals. J. Med. Educ. 58:343-348, 1983. Department of Pharmacology, Toxicology & Therapeutics, University of Kansas School of Medicine, Kansas City, KS, U.S.A.

LOCAL PRESCRIBING STATISTICS, GENERAL PRACTITIONERS AND DRUG SELECTION Y. Tomson, K. Holmberg, A. Higgmark, G. Tomson, B. Westerholm Swedish general practitioners (GPs) constitute 10% of all doctors but prescribe drugs for 50Z of the total sales value. Others develop, control and study drugs, but GPs decide who is going to get what kind of drug. Unfortunately GPs have been little involved in drug policy issues. To overcome this a study on local prescribing statistics was initiated in an area with 27 health centres (HCs) and 24 adjacent pharmacies covering a suburban population of 555 000 inhabitants. All pharmacies were already computerized for labelling and pricing of drugs and provided the statistics needed for a study period of 3 months. All prescriptions issued and delivered during this pe#iod were ineluded. HCs were chosen as unit of prescribing. These, patient and drug characteristics, were coded and computerized. In all 70 000 prescriptions were included. The physicians at the 27 HCs prescribed 736 of the about 1 800 d~ugs on the market, the two extremes using 175 and 448 different drugs. The six HCs with the ssme number of doctors and similar number of patients seen used between 229 and 391 different drugs. Fortytwo per cent of the drugs prescribed were included in the list recommended by the therapeutic committee of the hospitals. The amount of drugs prescribed in DDD/IO00 inhabitants/day varied threefold between the HCs. Analgesics, antibiotics, cardiovascular drugs and sedatives constituted 55% of all drugs prescribed. Twelve of the thirteen bensodiazeplnes on the market were prescribed by two HCs, one prescribed only six. Wide variations in prescribing was shown for the HCs. These differences formed the basis for local discussions. During a two day seminar with representatives from the HCs an essential drug list for GPs including 170 drugs was designed and the effects are followed. Development Unit of Primary Health Care, Stockholm County Council, Diagnosvigen 8, S-141 54 Huddinge, Sweden

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THE USE OF DRUGS - CONTINUING EDUCATION IN FAMILY MEDICINE

TYPHOID FEVER AND CHLOHAMPHENICOL USES : A NATIONAL SURVEY A. HELALI, F, GUENANECHE

I Block, 0 Svende~ The aim of the project is to improve the use of drugs in family medicine. I t is a j o i n t venture between the institutions of family medicine at the Swedish universities, the National Board of Health and Welfare, the unions of doctors in primary health care and clinical pharmacology, the Association of, Swedish County Councils, and the National Corporation of Swedish Pharmacies. I n i t i a l y an efficient organisation of continuing t r a i ning of family doctors in the use of drugs in family medicine was built. The proper setting for the training is the surgeries, where the doctors in primary health care have b u i l t their own training activities. Within the project experienced doctors in primary health care were invited to give their opinion on continuing training, educational models, technical means, and to analyse the needs and the outline of the organisation. Conclusions: CME material used in the doctors o f f i c e shall be: Relevant to family medicin practice; Problem/symptom oriented; The drugs in i t ' s context in relation to prophylaxis, non-pharmacological treatment; Common/essential problems; News and neglected problems. Fifteen items common in family medicine have been selected. The i n s t i t u t i o n s of family medicin have the respons i b i l i t y of creating working groups to gather, evaluate, l i s t and describe available educational materials. The i n s t i t u t i o n s are advisers. The CME group guarantees the q u a l i t y . The material are distributed through the local pharmacies, wich a l l belong to the National Corporation of Swedish Pharmacies. Through the pharmacies the physicians can also obtain t h e i r prescription patterns to use as a tool in t h e i r therapeutic auditing.

Oral chloramphenicol (CPL) i s u s e d m a i n l y t o t r e a t t h e enteric fever caused by Salmonella typhi. The aim o f t h e present study is to test whether there is a relationship between reported cases of thyphoid fever i n h o s p i t a l from a n a t i o n a l r e g i s t e r and t h e CPL c o n s u m p t i o n i n h o s p i t a l s . A national r e c o r d o f a n n u a l c a s e s o f t y p h o i d f e v e r (a n o t i f i a b l e d i s e a s e ) , from 1973 t o 1986 i s u s e d . The theoritical consumption called "estimated chloramphenicol u s e s " (ECU) i s c a l c u l e d u s i n g an a v e r a g e 1 . 5 g p e r d a y p e r case over a treatement p e r i o d o f 21 d a y s ( 1 . 5 g x 21 = 31.5 g). The r e a l consumption called "chloramphenicol u s e s " (RCU) i s c a l c u l a t e d from the sales volumes of the d r u g t o t h e h o s p i t a l s by t h e s i n g l e national center of drug supply. Finally a comparaison between the curve of ECU a n d t h e c u r v e o f RCU i s u s e d t o c h e c k t h e CPL utilization by p h y s i c i a n s . The m o r b i d i t y c u r v e shows 3 t o p l e v e l s . The f i r s t acme o f t h e d i s e a s e i s shown i n 1976 and i s followed by the s e c o n d i n 1979 a n d t h e t h i r d i n 1983. The c u r v e o f ECU shows t h e same t r e n d . The c u r v e o f t h e RCU shows an acme i n 1980 a n d 1984 w i t h one y e a r d e l a y from t h e t o p s o f t h e t y p h o i d m o r b i d i t y . However, t h e d r u g s a l e s a r e 4 t o 36 t i m e s o v e r t h e e s t i m a t e d c o n s u m p t i o n o f CPL. The p r e s c r i b i n g p a t t e r n o f CPL shows a g e n e r a l a g r e e m e n t w i t h m o r b i d i t y w i t h one year delay. Rowever, the utilization o f CPL i s 6 t i m e s l e s s in 1984 t h a n i n 1980. T h i s c h a n g e i s an i n d i c a t i o n of a better u s a g e o f CPL recently. Division de Pharmacologie - Institut National de Sant~ publique -4 chemin E1Bakr - El Biar - A l g i e r s (Algeria)

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RISK FACTORS FOR IBUPROFEN-ASSOCIATED RENAL IMPAIRMENT: AGING AND CORONARY ARTERY DISEASE M.D. Murray, D.C. Brater, and W.M. Tierney Prior epidemiologic investigations have fa-iled to demonstrate an association between ibuprofen use and renal impairment but have lacked sensitivity or were performed in subjects not at risk for its development. Using a computerized medica] records system to review records from a large general internal medicine practice, we identified 1908 patients who received their first ibnprofen prescription and had not been prescribed another nonsteroidal anti-inflammatory drug (NSAID) for at least one year following the ibuprofen prescription date. We then retrieved serum creatinine measurements performed within one year before and after receiving ibuprofen. We likewise formed a control group of 3933 acetaminophen recipients who had not received NSAIDs within the year before or after the acetaminophen prescription date. Using an algorithm designed by Bonney et al., renal impairment occurred in 343 patients (18.0%) receiving ibuprofen and 861 patients (20.5%) receiving acetaminophen. From univariate analyses, 18 statistically significant (p < 0.05) variables predictive of renal impairment were determined. However, multiple logistic regression analysis identified six independent predictors (adjusted odds ratio, 95% confidence intervals): increased age, prior renal insufficiency (2.56, 1.93-3.43), coronary artery disease (1.86, 1.14-3.04), male gender (1.42, 1.08-1.87), elevated systolic blood pressure, and diuretic use (1.35, 1.021.78). Although ibuprofen use was not among the independent predictors of risk when a]] 5841 patients were ana]yzed (1.05, 0.88-1.26), subgroup analysis revealed two risk groups for ibuprofen-associated renal impairment. These subgroups were 443 patients ~ 65 years of age (1.34, 1.05-1.72) and 87 patients with coronary artery disease (2.54, 1.38-4.68). Thus, elderly patients and those with coronary artery disease should have renal function monitored when ibuprofen is prescribed. Clinical Pharmacology Section, Wishard Memorial Hospital, iO01 West IOth Street, Indianapolis, IN 46202

SECONDARY PREVENTIONOF MYOCARDIAL INFARCTION. THE INFLUENCE OF CLINICAL TRIALS ON CLINICAL PRACTICE A Agustf, JM Arnau, JR Laporte, J Soler*, X Vidal Introduction.- Clinical t r i a l s have demonstratedthat in patients who have suffered an acute myocardial infarction (AMI), continued treatment with 6-adrenergic blockers (6AB) or acetylsalicylic acid (ASA) reduces mortality and the incidence of infarction. We have surveyed the influence, i f any; of the results of these t r i a l s on the prescriptions. Method,- The information in the discharge forms of a sample of 736 patients admitted to the Cardiology Department during 1982-88, and who had got over the acute ~tage of a transmuraI AMI, was analyzed. By means of a structured protocol, information was collected on the cardiovasvular and digestive antecedents, complications during admission, recommendeddrug treatment, and possible contraindications. Results.- Of the 736 patients, 637 (86%) were men and 102 T~omen; the mean age was 58.8 • 10.7 SD years. On discharge, 461 (63%) patients presented cardiovascular antecedents (CVA). During the study 267 from the 736 patients (36.3%) were prescribed BAB and/or ASA. A gradual increase in the prescription of these drugs was noted between 1982 (19.7%) and 1987 (53-64%). A 17% of patients who had not taken ASA and 47% of those who had not taken ~AB presented relative contraindications to treatment. Two hundred patients (27.2%) received a calcium channel blocking agent (CCB) not associated to ~AB. The use of CCB was more prevalent among patients with CVA and the use of AB was higher in patients without them. Conclusion.- CIinica] t r i a l s seem to have altered prescription habits for AMI patients. Their impact seems to have been limited by a considerable use of CCB instead of ~AB. Servei de Farmaco]ogia Clfnica. Departament de Cardiologia*. CS Vall d'Hebron. 08035 Barcelona.

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PP 10.39 T ~ lEE 0F M 3 N l ~ RE2ASE [8~AL DATA F0R [RI]G AND D I ~ MI0[fGY I ~ %TII{D I ( I ( ~ S[DILM IN R}~IMATICD I S 3 ~

]~=IIE-

Bbutt AD, Sane ~P, Baked R, F~rth~r }~, Bolar tlV, Vaidya AB. A rmtienwide M.R.S. of diclofamc sodium (D] (Voveran(R)) was carried out in 11,931 Indian patients suffering from 15 rheurmtic disorders. Over 2,500 doctors entered data on patient and disease charanteristics, efficacy and safety of therapy and cang~risbn of patient preferences between diclofemac and previous experience with nonsteroidal anti-inflannatory drug (NSAID). The data are analysed with on objective of obtaining epidenm'ologicinformation. Toe distribution of carmen conditions showed rheunmtoid 28.1%, ssteoarthrosis (OA) 24.8Z, soft tissue rhetmatism 12.4%, spendylosis 6%, and ankylnsing spondylitis (AS) 3.5% and gout Z%. Fast ,~E)had l ~ s t proportion of OA. As compared to North (N) and Fast (E', South (S) and E%st .%~'}showedlower proportion of gout and AS. Age distribution of 0A showed bhat 34-42% were is the age group of 31-50 yrs. N end E had significantly ic~_r proportion of elderly [>(f) yrs). ]he male to fs~ale ratio between the zones veied from 0.8-1:1. The tolerability of D was similar in all zones with 15.9-17.6% of patients reporting t~ronted effects (UEs). %he G.I.UEs were cxm~arable acro~s the zones, the ~dn UF_s were reported less freqt~ ently in S and E. Analysis of previous ),'SAIDuse (n=5567) s h ~ d a preference for combinations (35.6%> and llmprofen (30.7%) follc~d by others (2.4-7.9%). ]]~e combinations were the first choice for most rheunatic indications (]2/15). 7he order of preference far ~{AIDs was sot different across the diseases or zones. D was found superior to previous NSAID by 74% patients. Toe efficacy of D was good to excellent in 77 to 82%0 of patients suggesting tl~at the different geographic locations did not influence the response to D therapy. M.R.S. co~fld serve as an useful tool in disease and drug epidemiology }bwever, certain critical variables tend to be hissed, which need to be identified and included at planning Stage.

ANTI-RHEUMATIC DRUGS UTILIZATION IN HOSPITALS IN SLOVENIA, YUGOSLAVIA: 1983 - 1987. S. Cernelc The study presents the use of non-narcotics analgesics drugs (NNADs), non-steroid anti-inflamatory drugs (NSAIDs), and slow- acting antirheumatic drugs (SAARDs) in 1983-1987 in all hospitals (No=22) throughout the Republic of Slovenia (1.97 M inhabitants). Amounts of drugs delivered from hospital pharmacies to wards were collected for each year, and the data then converted into DDD/100 BD (defined daily doses/100 bed days) unit. DRUGS NNADs DIPYRONE COMBINATIONS ACETYLSALICYLIC ACID COMBINATIONS PARACETAMOL COMBINATIONS OTHERS

1983 1984

1 9 8 5 1 9 8 6 1987

17.23 16.90 18.16 20.46 21.76 5.43 7.55 8.57 9.20 10.39 1.91 1.80 1,55 1.89 1.62 3.34 3.67 4.11 4.37 4.67 0.63 0.47 0.51 0.32 0.66 0.18 0.19 0.18 0.32 0.40 3.25 1.88 1.87 3.06 2.33 2.79 1.66 1.76 1.78 1.94

NSAIDs 16.15 15,32 15.83 17.55 19.05 DICLOFENAC 2.99 3,85 4.30 5.27 5.96 IBUPROFEN 5.29 4.49 3.79 4.62 4.87 KETOPROFEN 2.68 1,92 2.63 3.07 4.25 PIROXICAM 0.92 2,53 2.68 2.43 2.35 INDOMETACIN 0.42 0,53 0.57 0.67 0.50 BUTYLPYRAZOLIDINE DERIVATIVES 2.26 1,36 1.05 0.47 0.31 OTHERS 1.59 0,64 0.81 1.02 0.81 SAARDs GOLD PREPARATIONS QUINOLINEDERIVATIVES PENICILLAMINE

1.88 1.65 0.14 0.09

237 256 0.16 0.05

3.6 3.45 0.10 0.05

3,62 3.51 0.09 0.02

2.91 2.75 0.09 0.07

Medical Department, llindustanCiba-Geigy Limited, 14, J.Tata Road, Panbay ~O0 O20, India.

Slovene data were compared with those of other countries. Characteristic data have been obtained for the use of anti-rheumatic drugs in hospitals, which serve as the basis for planning, checking, coordination, training, and improvement of treatment with this drugs. Faculty of Medicine, Vrazov trg 2, 61000 Ljubljana, Yugoslavia

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MEDICAL D A T A FILE OF U N I V E R S I T Y H O S P I T A L AS A POSSIBLE S O U R C E OF P O S T - M A R K E T I N G S U R V E I L L A N C E (REPORT NO.l) K.Katahira, T.Satoh, M . F u k u s h i m a , F.Okuyama, M . K a w a g u c h i , C . N a k a m i and A . S a k u m a The p u r p o s e of this study is t o - e x a m i n e the p o s s i b i l i t y of using the data file of c o m p u t e r i z e d h e a l t h i n s u r a n c e billing s y s t e m m a i n t a i n e d by our U n i v e r s i t y Hospital for p o s t - m a r k e t i n g s u r v e i l l a n c e (PMS) for a d v e r s e drug r e a c t i o n s (ADRs). W e s e l e c t e d w i d e l y - u s e d 12 drugs now r e q u i r i n g special attentions b e c a u s e of their p o t e n t i a l ADRs and c e r t a i n d i s e a s e s that might r e l a t e to the ADRs. The c o v e r a g e p e r i o d is January, 1982 - November, 1988. First,the ratios of p a t i e n t s w i t h the diseases to patients groups of the f o l l o w i n g three kinds were determined, p r o v i d e d that, for (A), the n u m b e r s of patients with the d i s e a s e s (numerators) were those c o u n t e d for the p e r i o d s after the drugs' a d m i n i s t r a t i o n months :(A) all the patients who took the drugs: (B)al/ the p a t i e n t s of the Hospital during the p e r i o d (i09, 088);and (C) all the p a t i e n t s who did not take the drugs and w h o s e c o n s u l t a t i o n c l i n i c s , s e x e s and ages w e r e m a t c h e d to group(A). Then, f o u r - f o l d tables of (A)-(B) and (A)-(C) combinations were prepared. The a s s o c i a t i o n s between the drugs and the diseases w e r e d e c i d e d to be significant w h e n the lower limit of 95% c o n f i d e n c e interval of each of the odds ratios c o m p u t e d f r o m the tables was larger than 1.0. There w e r e 52 d r u g - d i s e a s e c o m b i n a t i o n cases in which the d i f f e r e n c e s b e t w e e n (A) and (B) w e r e significant. 21 cases out of the 52 also s h o w e d significant differences when (A) and (C) w e r e compared. In conclusion, it was s u g g e s t e d that such a data file of our Hospital could be a p p l i e d to PMS for ADRS.

IN-HOSPITAL DRUGUTILIZATION STUDIES JM Arnau, JR Laporte, C Ara96n, E Colom4, J Costa, M Martfnez, C Rodriguez, X Vidal Introduction.- The quantitative and qualitative description of in-hospital drug use and its follow up allows to establish comparisons with other centres, to identify problems, and to improve drug use in clinical practice. Methods.- Our service carries out a qualitative evaluation of the use of drugs considered of interest by the Hospital PharmacotherapyCommittee. Somedrug u t i l i z a t i o n studies (DUS) done by the Clinical Pharmacology Department during 1986-88 are reviewed and presented. Results.- The studies have been classified according to method: 1) level of compliance with the Hospital Drug Formulary: study of the prescribed drugs not included in the Formulary; 2) consumption of high-interest drugs: time changes in restricted-use antibiotics and their free-use alternatives; 3) indications for use of new drugs added to the Hospital Formulary, ( i . e . , cefonic!d; 4) indications for the use of high cost drugs, ( i . e . , human albumin); 5) drug use in specific indications: evaluation of the treatment of postoperative pain. Conclusion.- DUS are a main tool for a Service of Clinical Pharmacology. They are useful in: 1) making recommendations to the Pharmacotherapeutic Committee; 2) editing information bulletins orientated towards practical problems; 3) organizing discusMon meetings with other clinical departments; 4) adding new strategies to existing therapeutic protocols; 5) carrying out additional studies. Servei de Farmacologia Clfnica. CS Vall d'Hebron. 08035 Barcelona

D e p a r t m e n t of C l i n i c a l Pharmacology, M e d i c a l R e s e a r c h Institute, Tokyo Medical & Dental University, 2-3-10, K a n d a s u r u g a d a i , Chiyodaku, Tokyo, 101, Japan.

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DRUG USE P A T T E R N A N D A D V E R S E D R U G R E A C T I O N HOSPITALISED PATIENTS V i n c e n t J. a n d 0 d i a 0.J. C o l l e g e of H e a l t h S c i e n c e s , Harcourt - Nigeria.

IN

A PRuSPECTIVE STUDY OF PRESCRIBING PATTERNS DURING P~EGNANCY

Moll~ Thomas, Rriya Abraham, Prabha Jairaj University

of P o r t

The p r e s c r i p t i o n p a t t e r n in a n y e n v i r o n m e n t is i n f l u e n c e d b y f a c t o r s i n c l u d i n g the d i s e a s e s p e c t r u m , d r u g p o l i c y , d r u g a v a i l a b i l i t y and the k n o w l e d g e o f the p r e s c r i b e r . In a s o c i e t y lacking any d r u g r e g u l a t o r y laws or s y s t e m for r e p o r t i n g and r e v i e w i n g a d v e r s e d r u g r e a c t i o n , a v a r i e t y of agents are o r d i n a r i l y a v a i l a b l e w i t h no c l e a r - c u t i n d i c a t i o n s and no f a c i l i t y for assessing their toxic potential. A s u r v e y o f the d r u g use p a t t e r n a m o n g i n - p a t i e n t s at the o v e r 600 - Bed U n i v e r s i t y of Port H a r c o u r t T e a c h i n g H o s p i t a l has b e e n done. 0ver-prescription, c o n t r a c d i c a t e d , p o t e n t i a l l y h a z a r d o u s and a d v e r s e l y i n t e r a c t i n g drugs as w e l l as u n d e s i r able p r e s c r i p t i o n s and s ~ b - o p t i n a l t r e a t m e n t w e r e o b s e r v e d in v a r y i n g d e g r e e s in the d i f f e r e n t ~epartments. The i m p o r t a n c e of p r e v e n t i n g drugi n d u c e d p r e s c r i p t i o n errors and d r u g - i n d u c e d m o r b i d i t y as w e l l as the r o l e o f the a b g e n c e of a portable National formulary and appropriate c u r r e n t i n f o r m a t i o n on c o m m o n l y u s e d d r u g s to p r e s c r i b i n g p h y s i c i a n s are d i s c u s s e d .

Studies on drug prescribing during pregnancy from India are few. This is a prospective study to determine the pattern of drug prescribing in patients attending an antenatal clinic. Total of 264 patients were interviewed and followed up during antenatal period and till delivery. 57~ of those who had been to general practitioners during various semesters of pregnancy were given some drug whereas of those attending a teaching hospital antenatal service, only 24.6% received any drug, Contrary to the reports that self prescribing is high, it was observed only in 5.6~ of patients. Majority of self prescriptions were for analgesics and antipyreties. (73.3%); antibiotics were only 0.7~. First trimester prescribing was maximal from general practice. The commonest groups of drugs prescribed were hormones (19.2~), whereas from teaching hospital it was only 6.2%. In the teaching hospital, the indications for use of hormones were more appropriate compared to general practice. Antibiotics were 7.6~ from general practice whereas nil from the teaching hospital; antipyretic-analgesie was 7.7% in general practice as against I% from the teaching hospital. No significant drug related problems were noticed in this study. Most patients did not have any clear idea as to the use of drugs during pregnancy and its possible effect on mother and fetus. ~here is over-prescribing during pregnancy especially in general practice and hence it is essential to health educate the target population and the physicians about drug usage. Department of Clinical Pharmacology, Christian Medical College & Hospital, Vellore - 632 004, S. India.

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HOSPITALIZATION CAUSED BY ADVERSE DRUG REACTIONS E. Vargas, M g M. G.Arenillas, M. Martfnez, L. Laredo, A. Moreno.

DRUG PRESCRIBING IN PATIENTS OVER 65 YEARS Z. Manoj lovi6 Rationality of specialist drug therapy prescribed to 154 patients older than 65 in 3 old people's home of Zagreb during 11 months was analyzed (route, dose and duration). Categories analyzed were: type and number of prescribed drugs, justifiability and adequacy according to age, exisa tence of better parallel drugs, contraindications clinically important drug interactions. There were 2C~ medical check-ups. In 146 cases 389 drugs were prescribed, in 117 cases (80.1%) the ~rescribed therapy was not rational~ There were 2.66 (!1.65) drugs prescribed per patient's visit. This is similar to those in similar researches. In almost all analyzed categories distinctive aberrations from the principles of rational prescribing were found. One hundred and sixty-one (4 1.4%) of all prescribed drugs were prescribed without justification; 103 (26.4%) were not correctly dosed, 75 (19.3%) were not adequate because of the patient's age. The duration of the therapy was inadequate for 60 (15.4~o) drugs, for 38 (11.3%) existence of potentially clinically important drug interactions was found and 15 (3.9%) were prescribed in spite of the existing contraindications. The results are suggesting an unexpectedly high degree of irrationality of specialists' drug prescribing to the elderly. By reducing the number of prescribed drugs and by improving the structure of prescribed drugs, it would be possible to increase the quality of drug therapy and to decrease costs. Clinical pharmacology still does not have an important place on this field of pharmacotherapy.

We have carried out a prospective surveillance of admissions related to adverse drug reactions (A.D.R.) in two departments of o u r Hospital (Cardiology and Internal Medeeine). During the years 1986 and 1987 we registered 1089 patients (660 in the Internal Medicine's department and 429 in the Cardiology's department). We reviewed all the admission and discharge charts, and we also asked the doctors in charge of the patients if they considered that any of the admissions could be related to A.D.R. 39 patients (3.6%) had A.D.R. when admitted to Hospital; one of them had two A.D.R. (gastric bleeding and digitalis intoxication). 31 of these patients were admitted to Internal Medicine (4.7%) of all the admissions in this department) and 8 to Cardiology (1.9%). The most frequently involved drugs in the Internal Medicine were NSAIDs (19 cases), Digitalis glicosides (4 cases), Hipoglycaemic drugs (3 dases) and in Cardiology Calcium antagonists (3 cases). Gastric Bleeding was the most frequent pathology presented in Internal Medicine (19 cases), while Heart Failure (2 eases) and Atrioventrieular Block (2 cases) were the most frequent in Cardiology. A.D.R. are an important cause of admission in both Internal Medicine and Cardiology in our Hospital. Servicio de Farmacologfa Clinica. Hospital Universitario de San Carlos. c/ Martfn Lagos. MADRID 28040

Section of Clin.Pharmmeol., Dept. of Medicine, Univ. Hospital Rebro, Zagreb, Yugoslavia

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DRUG UTILIZATION IN NIGERIA: PRESCRIPTION PATTERN OF ANALGESICS IN LAGOS. A.F.B. Mabadeje and S. A~ Mabadeje A questionnaire survey was conducted in Lagos to study the prescription pattern of doctors and the dispensing pattern of pharmacists and nurses concerning analgesics. 1000 questionnaires were sent out to doctors, dentists, pharmacists and nurses working in Lagos or visiting Lagos for medical conferences and workshops over a 26 month period. The first lot was sent out in October 1986 and reminders were sent in March, June, September and December 1987 and March, June and December 1988 respectively. The Response Rate was initially 12% in March 1987, 15% June 1987, 21% September 1987~ 25% December 198~ 27% March 1988, 29% June 1988, and 35% December 1988. 240 out of 600 (40%) doctors responded, 21 out of 100 dentists responded, 57 out of 250 (22.8%) pharmacists responded while 29 out of 50 (58%) nurses responded. Most of the doctors who responded 156 out of 240 (65%) were from the Teaching Hospital but most of the pharmacists who responded 39 out of 57 (68%) were in private practice. Paracetamol was the analgesic most frequently prescribed (I00%) followed by "Novalgin/Optalgin" 223 out of 347 (64%). "Tramal" was also freely prescribed 127 out of 240 (53%). Aspirin was seldom prescribed 68 out of 347 (28%). Most responders obtained their drugs from local manufacturers/suppliers 213 out of 247 (86%). Aspirin was incriminated as the analgesic with the most unbearable side effects (gastric irritation) by 187 out of 247 (75%). Only 9 out of the 223 respondents (4%) realised that dipyrone is the active constituent of "Novalgin/Optalgin". The study showed that dipyrone is still widely prescribed and dispensed in Nigeria. It also showed the need for continuing education of doctors, dentists and pharmacists about approved drug names. Departments of Pharmacology and Medicine, Lagos University Teaching Hospital, Lagos, Nigeria.

SEASONAL VARIATIONS IN THE PRESCRIBING OF ANTIDEPRESSANT DRUGS IN A SWEDISH COMMUNITY Bingefors, K.Z, Isacson, D.l, Bingefors, N.2 and Smedby, B.3 1Dept. of Social Pharmacy, 2Contre for Instrument and Measurement Technology, 3Centre for Primary Cam Research, University of Uppsala, S-751 23 Uppsala, Sweden. A number of studies have shown seasonal variations in the incidence of suicide and of depressive disordea~. A couple of studies have also shown cyclic variations in the prescribing of antidepressants. These studies, however, have only covered a few years. The aim of this study is to analyze the prescribing pattern of antidepressants over a 12-year period in a Swedizh community. Methods: Patterns of antidepressant drug prescribing between 1972 and 1984 in a total population of 21 000 inhabitants in a defined geographic area were studied by means of registering all prescriptions filled by the pharmacies in the area. Results: Between 1.6 and 2.2 per cent of the population obtained antidepressants at least once during a year. Women were much more likely to be treated than men, with more than twice the amount of prescriptions. Analysis of the prescribing pattern suggests a seasonal variation with low use in the summer and a somewhat higher use in November and December. This periodicity was confirmed by Fourier analysis. Men had a somewhat different pattern of use than women. Conclusion: We found a weak seasonal variation in antidepressant drug prescribing in our study but with a different pattern than that found by other investigators. The seasonal variation found in our study is compatible with the theory of pineal gland melatonin production during seasons with few hours of sunlight, related to depressive disorders.

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PP 10.50

REPORTING RATES OF EXTRAPYRAMIDAL REACTIONS IN THE UNITED KINGDOM - 1967 to 1982. M.D.Rawlins and D.N.Bateman Spontaneous reporting of suspected adverse drug reactions plays a critical role in the postmarketing safety surveillance of both new and established drugs. All such schemes involve substantial under-reporting though few attempts have been made to estimate the extent. A reporting rate of 10% has often, however, been assumed. The present study was carried out in order to measure the under-reporting of extrapyramidal reactions to metoclopramide (MCP) and prochlorperazine (PCP) in the UK.

CHARACTERISTICS OF LONG-TERM ALPRAZOLAM USERS G. B. Somer, L. SobeH. E.M. Sellers and M. Sobe]l Afprazolam, a triazolobenzodiazepine, is marketed as an effective treatment for anxiety disorders and anxiety-associated with panic and depression. Although it is one of the most commonly prescribed drugs in North America, little is known about the long-term user (e.g. prevalence, indications for use, pattern, withdrawal symptoms), in an attempt to learn more about this population, a questionnaire survey was conducted. Current alprazolam users were recruited through media advertisement. Of the 264 ad respondents, 71.2% (188) completed the mailed questionnaire. Distribution of the responses were completed by the use of SPSS-X summary statistics. Characteristics of long-term (_~ 3 months) alprazolam users were as follow: 63.9% female; mean age 52.1 ; prescribed alprazolam for anxiety (35.2%), panic attacks (22.9%), depression (16.5%), insomnia (11.6%); prior to using alprazolam 66% were prescribed another drug to control symptoms; mean use of alprazolam 2.2 years and mean daily dose was 1.5 mg. The key findings to emerge from the survey were: a sizeable number of individuals (37.2%) reported taking the drug soley "as needed" rather than as prescribed; 69.2% report that their physician never discussed the possibility of decreasing their consumption of alprazolam and 73.4% report that their physician had never discussed the possibility of discontinuing. With respect to discontinuation, 54% report that they were told nothing, 26.1% were told that alprazolam should be discontinued gradually with supervision and 14.2% were told that discontinuation would not be a problem. 65.7% have tried, on at least one occasion, to decrease or cease taking alprazolam. The mean number of discontinuation attempts was 2.79 and 57% experienced some withdrawal symptoms (mean number of withdrawal symptoms experienced was 9). The most frequently reported withdrawal symptoms included anxiety (75%), tension (60%), insomnia (55%) and 44% experienced the urge to take alprazolam. These findings, while restricted to this survey population, suggest that physicians are generally not discussing the implications of Iong4erm alprazolam use and/or its discontinuation. Gail R. Somer, M.A., Clinical Psychopharmacology Program, Addiction Research Foundation, 33 Russell Street, Toronto, Ontario M5S 2S1, Canada.

We have recently established the incidence of extrapyramidal reactions to MCP and PCP from the results of a community-based study (Bateman et al., 19B9 Quarterly Journal of Medicine). From the annual number of "first" prescriptions for these two drugs, issued between 1967 and 1982, the "expected" number of reported reactions was calculated. This was compared with the "observed" numbers reported annually to the Committee on the Safety of Medicines over the same period. The reporting rate (observed + expected %) of dystonia and dyskinesias varied annually from 0.5% to 1.5%; whilst the reporting of parkinsonian reactions has been consistently lower than 0.1%. Reporting rates, even for severe reactions that can be readily identified, may be substantially less than most estimates have acknowledged. Wolfson Unit of Clinical Pharmacology, Department of Pharmacological Sciences, The University, Newcastle upon Tyne NEI 7RU, U.K.

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PP 10.53

USE OF BENZODIAZEPINES IN A SWEDISH C O M M U N I T Y PATTERNS OF INDIVIDUAL USE OVER TIME

ANALYSIS OF THE SUPPLYOF EXPECTORANTSIN THE SPANISH DRUG 'MARKET A Figuera&, E Ballarfn, J Juan, E P~rez, L Vendrell Between 1981 and 1987, the most consumed ATC Classification therapeutic subgroup in Spain was the expectorants (R05C). In 1987 this subgroup accounted for ~.6% (102 million; 2.55 US per inhab) of the total drug expenditure; a fixed-dose combination of bromhexine + ~iphenhydramine + ephedrine + codeine + noscapine + papaverine was sixth among the most consumed preparations in the Social Security. Expectorants do not produce any clinical benefit. Their use is associated with some adverse reactions. During 1988 there were 341 preparations Of this subgroup marketed in our country, containing 1,374 active principles (x = 4.08; SD = 1.82). Of these, 276 (81%) contained one or more antibiotics associated with expectorants, mucolytics or antitusives. Semi-synthetic penicillins are present in 112 preparations (55%), and cotrimoxazole in 75 (27%). Ambroxo] is the most frequent sing]e active principle. Of principaIe, (5% of the t o t a l ) . 75% of the supply corresponds to preparations with three Or more active principles. Somoof them (citiolone, dipyrone, retinol) were present at infratherapeutic doses. 12% are irrational or dangerous fixed-dose combinations of fixed-dose combinations. A 50% of the anti-infectives in this group are not of first-choice in respiratory contidions. 5.2% of the products contain three or more anti-infectives, 23% at infratherapeutic doses. Servei de Farmacologia Clfnica. CS Val] d'Hebron. 08035 Barcelona.

Isacson D, Carsj8 !<, Bergman U., Centre for Primary Care Research, Dept of Social Pharmacy, University of Uppsala and

Dept of Clinical Pharmacology,KarolinskaInstitute, Stockholm. Considering that long-term use and dependence has been viewed as one, i f not th___eemajor , problem with the use of benzodiazepines surprisingly l i t t l e research has focused on patterns of individual use of benzodiazepines over time. Method: In 1976 users of benzediazepines in a total population of 21.000 inhabitants in a defined geographic area were identified in a research registry based on prescription records. The use patterns among these individuals during the time period 1977-1984 were analyzed.

Results: About two thirds of the 2.000 users identified in 1976 were users during the next year as well, 45 percent were still users after four years and one third had a continuous use during the whole eight year follow-up period. The study showed that age was of importance for the development of long-term use. Older users continued to use benzodiazepines to a much greater extent as compared to younger users. Women had a slightly greater tendency toward continuous use as compared to men. Furthermore, it was shown that heavy users of benzodiazepines in 1976, i.e., those 33 percent of the benzodiazepine users with the heaviest use that year, to a much greater extent exhibited long-term use during the follow-up period as compared to the individuals with lower use in 1976. Conclusion: The study showed that a substantial proportion of a defined population continued using benzodlazepines over an extended time period. Thus, further pharmacoepidemiologiea] studies of long-term use of benzodiazepines are needed. Centre for Primary Care Research, Dept of Social Medicine, AkademisI
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PP 10.54

THE PATTERN OF ANTIHYPERTENSIVE TREATMENT IN SUDAN M E BAKIRAHMED

YUGOSLAV MARKET OF ANTIULCUS DRUGS 1984-1988. S. Radutovid and T. Ka~id

The antihypertensive treatment of 85 patients with hypertension (mean age 49 ~ 12 (SD) year)~assessed. Their mean blood pressures were 162 m m H g systolic and 102 mm Hg diastolic, indicating overall poor control. Half of the patients were not taking regular treatment. The commonest drugs used were Thiazide diuretics, Mythylopa, Reserpine and B-Blockers in this order. One third of the patients needed more than one antihypertensive durg to control their blood pressures. The Cardiac compliaations occured in 18% of patients while cerebrovascular and renal eomplicat tions occured in 13% and 14% each~ The poor availability and high cost of antihypertensive drugs remains the most important factor contributing to poor control of hypertension in Sudan. Faculty of Medicine. Department of Med• P O Box 102 Khartoum SUDAN

Consuption (DDD/1000 inhabitants/day) of antiulcus (AU) drugs, market and prices in Yugoslavia (YU) were analysed within the last 4 years period and compared with data from W.Germany, Scandinavia and AustraLia. Total consuption of A U drugs in comparison with above mentioned countries was not that large. However, after stagnation, since 1984 sales of A U drugs, in contrast to other countries, are constantly showing a growth (15% per year). This growth is exclusively cause by greater consup. tion of H2antagonists , because the sale of antacids is rather low and is stagnating. Cimetidine reached m a x i m u m sales in 1984 when it had 10% of market share. The introduction of ranitidine quickly increased partcipation of H 2 antagonists in total A U consuption, so that in ]987 they had a market share more than 35%. In contrast to other countries, where consuption of cimetidine and ranitidine is equal, sales of ranitidine in Y U are ten times higher! The reasons for this should be sought in aggressive advertisment of pharmaceutical industry, as well as in price policy. Consuption of pirenzepine and sucralfate is rather low (7 times lower than Sveden). Ranitidine therapy is relatively more expensive in Y U than in other countries, because the prices of the latest H~antagonists are lower and lower all over the World and hi@"her and higher in YU. If the price for i D D D of antacid is i, the price for sucralfate is 3, pirenzepine 3~ cimetidine 4, ranitidine 5 and famotidine 6. Price ratio of cimetidine and raniUdine in comparison with antacids in other countries is 3:1. Price for I D D D of any A U drug in Y U is lower in average i0 times from price in W.Germany. It is necessary to return the reputation of antacids in ulcus therapy and be more critica] with the acceptance of latest A U drugs. Inex Hemofarm, Drug factory,26300 Vr~ac and Dept. pharmacol., Med. fac.,li000 Belgrade - Yugoslavia.

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EFFECT OF NIFEDIPINE ON SERUM THEOPHYLLINE LEVELS IN

LIMITING PRESCRIBING BY EXCLUSION OF OTC MEDICINES. M.C. Henman, C. Ferrando and 0.I. Corrigan.

ASTHMATIC PATIENTS WITH HYPERTENSION

A limited prescribing list was introduced in 1982 in Ireland by the de-listing of OTC medicine such as antacids, simple analgesics, cough and cold preparations and certain other medicines, and it has been suggested that this was followed by increased prescribing of POM preparations (C. Ferrando, et al, Drug. Intell. Clin. Pharm. 21, 653, 1987). The sector of the health service (GMS) affected by the list supplies medicines free of charge to those on low incomes and compared to 1981 the number of prescription items per patient fell by 4% in 1982 and by 20% in 1983. However from 1983 successive increases in the number of prescription items per patient were recorded such that by 1987 the figure was only 1.1% below the 1981 value. The visiting rate also showed a similar initial pattern, decreasing by 1.8% in 1983 compared to 1981 but rising in each of the following years to reach a value of 7.6% above that recorded in 1981. Associated with these changes was s increase in the prescribing frequence per IO00GMS patients of the H2 - receptor sntagonist drugs by a factor of 2.2, an Increase in the prescribing of carbocisteine by a factor of 2.3 and of mefenamic acid by a factor of 1.6 compared to 1983 figures and much greater increases compared to 1981 values. A detailed examination of the changes in drug utilization that occurred in the GMS and non-GMS sectors of the health service together with the effects of alternative policy measures will be discussed. Departments df Pharmacology and Pharmaceutics, Trinity College, 18, Shrewsbury Road, Dublin 4, Ireland.

L.Ero~lu E.Y11maz and A.Canberk Theophilline (T) is a drug with a narrow therapeutic range and its serum level is affected by several drugs. Nifedipine (N) is being used with increasing frequency for the treatment of angina and hypertension in asthmatic patients. Therefore, the effect of N on serum T levels in 13 female hypertensive patients with asthma was investigated. After administration of a slow release T preparation in a dose of 200 mg bidaily for 15 days, the trough serum T level (11.2 ! 2.7 ~g/ml) was obtained. The clinical effectiveness of this level was evident in pulmonary function tests. Then, i0 mg bidaily N was added to therapy. No change has been observed in serum T level (11.4 + 3.7 pg/ml) after 15 days of simultaneous use, however after 45 days serum T level (7.3 + 2.1 pg/ml) was significantly reduced. There were no alterations in clinical responsiveness of either of these drugs. The effectiveness of low T level has been thought to be due to the prolonging effect of N on broncodilators. Department of Pharmacology, Istanbul Medical Faculty, University of Istanbul, r

Istanbul, Turkey

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INTERACTIONS BETWEEN NIFEDIPINE AND OMEPRAZOLE

EEES NDrDIPI~E ~ ~ HETAADHR~BGIC ~ AGRaB? R Horstmann, H. Weber, W. Wingender, K.-D. Pfm~sd%and J. Kuhlmenn To evaluate the interactions between the ca-antagonist nimodipine (N) and the beta adrenoceptor blockers propranolol (P) and atenolol (A) two randomized triple crossover trials were carried out with 12 healthy volunteers each. After 4 days of a t.i.d, oral treatment with 30 mg N or 40 mg P (study i) or 25 mg A (study 2) or the combination of both drugs (C) the pharmacokinetic profile of both drugs was determined on the fifth day of treatment. Hemodynamic effects were assessed by heart rate (HR), blood pressure (BP) and echographically registered cardiac output (CO) and the results compared to baseline values. Results (ar.mean+S.D.): -- HR(min -I) meanBP(mmHg) CO(i/min) Baseline 63+11 90+8 6.8+1.7 N 587 8 8577 6.7~2.3

M. Danhof, P.A. Soons, G. van den Berg, P. van Brummelsn, J.B.M.J. Jansen, C.B.H.W. Lamers and D.D. Breimer Omeprazole (OMP) seems to inhibit in-vivo oxidative metabolism of some drugs and exhibits hloodflow dependent clearance. Nifedipine (NF), also a high clearance drug, increases liver bloodflow and is extensively oxidised. Mutual interactions between OMP and NF were studied in two groups of i0 nun-smoking healthy male volunteers using a 3-way randomized cross-over design. i_~. Effects of single dose (20 mg po) OMP and short-term (7 days & 20 mg po) OMP treatment on NF (i0 mg po caps.) kinetics and effects, and on intragastric pH were assessed (placebo controlled blind study). Results: table i. 2. Effects of single dose NF (i0 mg po) and short-term NF (5 days i0 mg tid) on ICG clearance (15 min after NF) and OMP (40 rag iv in i0 min, 30 min after NF) kinetics were assessed (controlled open study). Results: table 2. TABLE 1

I

control

1 k OMP

7 days OMP

median pH (0-8h) I 1.3 1.5 1.43186.3 range I 0.9 - 1.9 0.9 - 3.3 CL NF (i/min) 11.25 • 0.37 1.18 9 0.34 0.99 • 0.32 Cmax NF (ng/ml) I 92 • 61 84 • 59 80 • 45 AUC M-0 (ng.h/ml) 79 • 30 81 • 31 88 • 39 tachycardia (bpm) 17 • 9 i0 9 9 [ ii • 6 TABLE 2 CL ICG (mi/min) CL OMP (ml/min) t~ OMP (min)

control I 1 x 833 • 214 ii067 • 480 • 282 415 • 52 • 27 55 •

NF 169 232 34

5 days NF 960 • 265 415 • 212 50 • 23

P

0.02 0.50 10.67 10.06 0 01 0.03 0.61

Large variabilit in kinetics of iv OMP was not related to sparteine polymorphism nor to NF and phenytoin kinetics. Short-term OMP lowers the clearance of oral NF but singledose OMP does not so. Clearance of iv OMP was lowered by single-dose and Shortterm NF despite an increase of apparent liver bloodflow. Center for Bio-Pharmaceutical Sciences, Div. Pharmacology and Leiden University Hospital, Dept. Gastroenterology, P.O. Box 9503, 2300 RA Leiden, The Netherlands

A

557 8

78u

7.471.3

C 547 7 8179 6.672.2 Baseline 597 6 8577 6.171.2 N 59~ 8 88~8 7.571.3 p 527 4 7977 7.171.2 C 53~ 5 7975 7.371.5 Descriptive analysis of AUC, C and t did not [ndimax o ~ pXharmacoklnetle cate an interaction with respect a . parameters. Conclusions: N itself did not elicit hemodynamic effects whereas P and A caused expected decreases in HR and BP. CO was not markedly influenced by any treatment. Cardiovascular changes under P and A were not~modified by N. Pharmacokinetic parameters were not influenced by combined therapy. These data evaluated in healthy volunteers suggest that N can be administered concomitantly with P or A to patients without the risk of a drug interaction. Bayer AG, Pharma-Forschungszentrum, Institut f~r Klinische Pharmakologie, D-5600 Wuppertal 1

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PHARMACOKINETIC DRUG INTERACTION BETWE~I~METOPROLOL AND CALCIUM ANTAGONISTS S.R.C.J.Santos, S.Storpirtis, J.G.N.Tavares, D.F.A.Chamone & J.H.Helou

NO PHARMACOKINETICINTERACTION BETWEEN THE NEW ANTIARRHYTHMIC PIRMENOLAND NIFEDIPINE K.-J. Goebel*, W. NuBbaumt, K.-O. Vollmer *, T. Chang2 Pirmenol, a pyridinemethanol derivative, is a new Class IA antiarrhythmic undergoing clinical t r i a l s . Since vent r i c u l a r arrhythmias frequently occur in the course of an existing coronary heart disease, calcium antagonists like nifedipine are often concurrently administered with antiarrhythmic agents. To investigate a potential pharmacokinetic drug-drug interaction, 1Z healthy subjects received in a randomized, two-way cross-over fashion single doses of pirmenol (100 mg capsule) or nifedipine (ZOmg tablet) alone and during nifedipine or pirmenol treatment (20mg b . i . d . ; I00 mg b . i . d . ) . Blood samples were taken at preselected time points, and plasma was analyzed for plrmenol and nifedipine using validated chromatographic methods (HPLC,GC). Pharmacokinetic parameters were derived from individual plasma concentration-time curves and compared by means of analysis of variance. Mean plasma concentration-time curves for pirmenol with and without concomitant n~fedip~ne administration were nearly superimposible. Mean elimination rate constants (Xz), half-lives (T89 and Tmax-values were v i r t u a l l y identical. Differences in mean Cmax- and AUC(O--)-values (13.3% and 8.6%) were s t a t i s t i c a l l y not significant as obtained from analysis of variance. Mean maximum plasma concentrations (Cmax) for nifedipine decreased by about Z0%, and a 33% increase in time for Cmax (Tmax) was observed in the presence of pirmenol. However, these differences did not reach statistical significance. AUC(O-=)-, Xz- and T89 Were nearly ident i c a l for both treatments. Results show that there is no change in pirmeno] pharmacokinetics under concurrent nifedipine treatment and no significant effect of multiple-dose pirmenol administration on nifedipine kinetics. *GSdecke Research Institute, D-7800 Freiburg, FRG 2Parke-Davis Research Division, Ann Arbor, MI 48105, USA

The present study reports the pharmacokinetic drug interaction between Metoprolol (M, 200rag/d), a cardioselective 8-a~irenoreceptor antagonist and Nitrendipine (N,20mgoi.d) or Verapamil (V, 80r~ o.i.d.) , both calcium antagonist drugs in healthy volunteers. After chronical oral dose, N and V increased Metoprolol plasma levels with prolongation of its lon~ elimination half-lives from 6.04~0.73 h (XZSEM) to 9.43-1.80h (p~0.05) or to 9.41~1.34h (pS0.05), respectively. Overall elimination rate+constant, Kl3, de creased from 0.3242-0.0467h -l to 0.2438-0.0401h -I or to 0..2648~0.0256h-I when M were associated to N or V,respectively. Any changes on Vdap or CZ i of M were observed after coadministration with N or V. Only urinary excretion of unchanqed M was increased (p~0.001), after N coadministration, while M as unchanged compound (p~0.001) a n d a s e-hydroxymetoprolol (p~0.05) were both increased when V w a s coadministered. Because of its high lipophyli_ city, M is extensively metabolized to be excreted. N and V showed to be preferencial substrates relative to M in liver. Based on this study a special attention must be used for the prescription of associated therapy for chronical treatn~nt involving M a n d these calcium antagonists for patients frc~ Intensive Care Units with miocardium infarction, heart fail, liver disease, hepatorenal impair ment, because of the acctm~lation of clinical relevance for M and its main metabolites. Center of Studies on Clinical Pharmacology - Research Lab. - Heart Institute - Medical School - University of Sao Pau io - Av. Dr. Eneas C a r v a ~ o de Aguiar, 44 - 05403 Sao-Paulo - SP - Brazil.

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POTENTIAL INTERACTION BETWEEN VERAPAMIL AND PROPRANOLOL G.T. Helnnes, D.L. Hurdoch, G.D. Thomson, G.G. Thompson, G.D. Hurray and H.J. 8rodie A potential drug interaction between verapamil (V) and prepranolo] (P) was investigated by comparing V 120mg, P 80mg and the combination (V 80mg + P 120mg) in a doubleblind, placebo controlled, randomised, crossover study in six normal males. Subjects were given single doses (day I) followed 48 h later by repeated administrations thrice daily for six days (days 3-8). After single and repeated doses, plasma levels of V, norverapamil and P were monitored for 48 h. On days I and 8, PR interval, resting and post exercise heart rate (HR) and blood pressure (BP) were recorded for 8 h after drug administration and hepatic blood flow (HBF) was estimated from indocyanine clearance. On single doses, V clearance was reduced after the addition of P (mean • SD, 8.1• I/h vs 6.9• p < 0.03) and P Cmax was increased after the addition of V (0.068• mg/l vs 0.119• p <0.05). After repeated doses, tendencies towards reduced V clearance and increased P AUCo_2Ahduring combination treatment did not reach significance. BP was reduced more by V + P than by either drug alone but only for reduction in resting systolic BP after single doses was the response greater than additive; 2.5 h after drug administration : placebo 114+16 mmHg, V 111+10, P 109• V + P 100+4, p <0.05. For PR interval and post-exercise HR, there were trends for greater than additive effects with V + P but these failed to achieve significance. There was no significant change in apparent BBF after either drug alone or in combination. This study provides little evidence that the pharmacodynamic effects of V and P are more than additive. The minor pharmacokinetic interactions observed are of uncertain relevance. University Department of Hedieine, Western Infirmary, Glasgow G11 6NT.

D O S E L I N E A R i T Y OF A F I X E D E X T E N D E D - R E L E A S E COMBINATION TABLET OF FELODIPINE AND METOPROLOL A-M. Tallberg, R. Bergstrand,K. Lidmmn,C-G, Reg&rdhand K. Wingstrand

(ER)

Propranolol affects the pharmacokinetics of felRdipine (F, Plendil @) in contrast to findings with metoprolol (M, Seloken ~). Modest changes in M pharmacokinetics induced by F are unlikely to be clinically important (1). The pharmacokinetics of three different acute doses of a fixed ER combination tablet of F and M were compared in order to investigate dose linearity. Methods: Twelve healthy male volunteers (aged 23-34 years) participated in this double-blind, randomized, cross-over study. Three different doses of F+M (5+50 mg, t 0+100 rag, 20+200 mg) were compared and placebo was used as control. Blood samples were collected over 24 hours. The plasma concentrations of F and M were determined by specific gas chromatography methods. Results: The mean plasma peak concentrations (Cmax) and the areas under the plasma concentration vs time curves (AUC) were: F (mg) 5 (nmol/L) C[•nx

AUC (nmol'h/L) SD

M(mg) 10

20

50

100

200

2.4

5.1

9.3

58

t00

218

0.9 19 7

1.6 48 16

4.3 90 29

41 916 712

68 1622 1237

130 3679 2685

A proportional increase in studied parameters of both F and M was obtained except for AUC of F. The analysis showed that AUC of F after 5+50 mg F+M was lower (p<0.05) than the corresponding dose-normalised areas for the two higher doses. Conclusion: No significant pharmacokinetic interaction between F and M occurred with the fixed ER combiantion tablet since dose linearity of both F and M could be established. The plasma levels of F with the lowest dose were close 1o the detection limit, which might explain the slight deviation in AUC.

(1) Smith SR et al. Eur d Olin Pharm 1987;31:575-8. Clinical Pharmacology, Cardiovascular Research, AB H&ssle, S-431 83 MSIndal

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THE EFFECT OF PRETREATMENT PERIODS OF DILTIAZEM ON THE NIFEDIPINE KINETICS

EFFECTS OF DILTIAZEM ON THE SERUM PROTEIN BINDING OF BASIC AND ACIDIC DRUGS.

K. Ohashi~ T. Sudo, T. T a t e i s h i , K. Sakamoto, N. Toyosaki, S. Hosoda, A. Ebihara, T. Toyo-oka. Diltiazem(D) and n i f e d i p i n e ( N ) are heterogeneous compound. We have reported t h a t the combination therapy o f D and N is c l i n i c a l advantageous in angina p e c t o r i s . Also, marked increment o f plasm N level was observed by D therapy. This mechanism is suggested t h a t D may i n h i b i t N hepatic o x i d a t i o n . The aim o f t h i s study was to evaluate the e f f e c t o f pretreatmentperiod o f D on the pharmacokinetics o f N. This study was performed three d i f f e r e n t p r e t r e a t ment periods o f D. Study A (Single dose-pretreatment):60 mg D was p r e t r e a t e d a t 1 hr before s i n g l e oral a d m i n i s t r a t i o n o f 20 mg N in 6 healthy male volunteers(23-29 years ). Study 8 (3 days' p r e t r e a t m e n t ) : 60 mg O, three times a day f o r 3 days, were given before the a d m i n i s t r a t i o n o f 20 mg N in 6 male volunteers(22-32 y e a r s ) . Study C (6 days' p r e t r e a t m e n t ) : 60 mg D, three times a day f o r 6 days , were administered before 20 mg N(20-22 y e a r s ) . Blood samples were taken f o r the measurement of plasm N level (by HPLC method). Blood pressure and h e a r t r a t e were moni t o r e d . Plasm N l e v e l s were elevated by a l l pretreatment periods o f D. Area under the plasm N l e v e l - t i m e curve(AUC ) was increased pretreatment period-dependenly by 35.1, 151.1, 188.0% f o r Study A,B,C, r e s p e c t i v e l y . Total c l e a rance o f ~ was decreased period-dependently by - 2 4 . 0 , -58.2, -63.9% f o r Study A,B,C, r e s p e c t i v e l y . Both s y s t o l i c and d i a s t o l i c blood pressures were more decreased by N with D than t h a t w i t h o u t D. D pretreatment a l t e r e d the pharmacokinetic p r o f i l e s o f N, presumably i n h i b i t e d the hepatic o x i d a t i o n o f N. Three days' pretreatmefit period o f D is enough to decrease the systemic clearance o'f N.

C. Aguirre, J.M. Rodrlguez-Sasiain, R. Calvo, R. Martinez, E. Su~rez. Diltiazem (DI), is a drug highly bound To plasma proteins. The percentage of DI free fraction range from 19 to 22% being independent of the plasma DI concentration (J. Pieper, Ciin. Pharmacol. Ther. 35, 266, 1984). The proteins implicated on binding are mainly albumin and elacid glycoprotein (AAG). Consequently, DI could be a potential displacing to other substances That bind to albumin (acidic drugs) or to AAG (basic drugs). Therefore, we selected in this study acidic, neutral and basic drugs at Therapeutic concentrations, i.e. 14C-diazepam (D) (I ~g/ml), 14C-warfarin (W) (] pg/ml), 3H-penbu%olol (P) (500 ng/ml) and 3H-morphine (M) (i00 ng/ml), and we studied the effect of DI (800 ng/ml) on Their protein binding. The percentages of free fraction of D, W, P and M were determinated in serum of five healthy volunteers by ultrafiltration (Amicon-MP81) and quantified by scintillation spectrometry. In presence of DI, free percentage of D increased 30% (P
C l i n i c a l Pharmacology, J i c h i Medical School, T o c h i g i , 329-04, Japan.

Dpto. Farmacologfa. Fac. Medicina. Universidad del Pals Vasco. 48940 Leioa (Vizcaya). Espa~a.

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COMBINED THERAPY OF NIFEDIPINE AND DILTIAZEM ON ANGINA PECTORIS N. Fukuma, T. Saito, N. Hata, H. Kishida, H. Hayakawa, H. Okumura We evaluated the antiangina~ e f f e c t s of Nifedipine(N) alone, Diltiazem(D)alone, and the combination(N+D). Subject and Method: I I p a t i e n t s with p o s t i n f a r c t i o n angina, having anginal attacks once a day or more, were studied. E a c h p a t i e n t received e i t h e r N(30-4Omg/day), D(90-12Omg/day) or the combination. Plasma concentration of N and D was determined before and at I , 2, and 4hr after administration. Antianginal e f f e c t and HR response were assessed by Holter ECG before and a f t e r treatment. Result: ( I ) Plasma concentration of N and D

ADVERSE PHARMACODYNAMIC INTERACTIONS BETWEEN METOCLOPRAMIDE AND LOW DOSE DOPAMINE INFUSION : A POTENTIALLY IMPORTANT INCREASE IN POTASSIUM EXCRETION.

before

lhr

2hr

4hr

Conc. o f N

N N+D

21• 81•

106• 234•

52• 153•

33• 86•

Conc. of D

D N+D

27• 30•

34• 32•

36• 32•

38• 35•

(*p
(ng/ml)

(2) The heart rate a f t e r N+D was increased s i g n i f i c a n t l y i~ comparison with control and D alone, but showed no s i g n i f i c a n t change in comparison with N alone. (3) The frequency and the duration of ST d e v i a t i o n a f t e r N+D were decreased, compared with c o n t r o l , N and N+D. Conclusion: I t is suggested t h a t the combination can be used w i t h o u t adverse hemodynamic reaction of N. The I s t Department of I n t e r n a l Medicine, Nippon Medical School, I - I - 5 Sendagi, Bunkyo-ku, Tokyo 113, Japan

T.M.MacDonald, R.F.Jelffey*, M.J.Jamieson & M.R.Lee'. Low dose dopamine (DA) is commonly used in the intensive care setting to improve renal periusion and promote a diuresis in patients with incipient renal tubular necrosis. These ill patients frequently require antiemetic therapy. The beneficial renal effects of dopamine are due to stimulation of the DA, receptor. The antiemetic effect of dopamine antagonists is due to DA2 blockade. We have examined whether the DAJDA2 antagonist metoclopramide (MC) or the DA~ antagonist domperidone (DP) produced clinically significant pharmacodynamic interactions with low dose dopamine infusion. 9 healthy male subjects were each studied on three occasions at least 7 days apart. They recieved a 200 mmol Na* diet for 5 days prior to each study day. Renal plasma flow (RPF) and glomerular filtrat)on rate (GFR) were measured by constant infusions of para-aminohippuran and polyfructosan. Natriuresis (U,,V), kalfuresis (UKV), GFR, RPF, plasma aldosterone (ALDO), and supine blood pressure (BP) were measured every hour for 6 hours. At two hours, placebo, metoclopramide 20rag or domperidone 20mg was given in a randomised single blind fashion. At 4 hours an infusion of dopamine at 2#g/kg/min was given for 2 hours. Area under curve was calculated for each parameter in each subject at 2-4 and 4-6 h and Wilcoxon signed renk te.~ts were performed between treatments. Results are given as median and 95% CI. Between 2-4 h MC reduced U,,V (-132, 95% CI -199, -61 mmol) and lowered BP (-13/-15, 95% CI -19/-23, -2/-8 mmHg) when compared to placebo but DP was without effect. Plasma ALDO was increased by MC (92, 95% CI 42, 182 pg/ml) over 2-4 h when compared to placebo but decreased over 4-6 h (-62, 95% CI -124, -22 pg/mi), but again DP was without effect. Over 4-6 h when MC was given, dopamine increased UKV (45, 95% CI 3, 84 mmol) and increased diastolic BP (14, 95% CI 2, 26 mmHg) when compared to placebo. There were no significant effects of MC or DP on RPF or GFR either before or after dopamine. Neither MC nor DP cause clinically important antagonism of the renal haemodynamic effects of dopamine. MC alone lowers blood pressure and causes sodium retention, probably due to aIdosterone release. An increase in UKV occurs with dopamine when MC is given. This may have clinically important effects in acutely ill patients and requires further investigation. Clinical Pharmacology Unit, University of Aberdeen, Scotland AB9 2ZD & *Clinical Pharmacology Dept. University of Edinburgh, ,ScotIand EH3 gYW.

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DIGOXIN PLASMA CONCENTRATIONS AND SYSTOLIC TIME INTERVALS DURING ADMINISTRATION OF EPANOLOL WITH DIGOXIN R.___A. Lefebvre*, M.G. Bogaert and D. Duprez

THE EFFECT OF A SINGLE 4MX;ORAL DOSEOF CALCIUMANTAGONIST LAClDIPINE ON THE PHARMACOKINETICSOF DIGOXIN S.T. Hall, S.M. Hardinq, D.M. Anderson. C. Ward and L.A. Stevens There have been several reports indicating that calcium antagonists as a class decrease the clearance of digoxin (mainly renal clearance) leading to increased plasma levels. Since digoxin has a low therapeutic index, this may have a significant effect on the pharmacological response to the drug. Lacidlpine is a dlhydropyridine calcium antagonist currently under development and its effect on the pharmacokinetics of digoxin has been investigated. Twelve healthy male volunteers each received as a randomlsed, double-blind cross-over study, a single oral dose of 4mg lacidipine and placebo when at steady state on a daily dose of digoxln for seven days (O.25mg following a single 0.Gmg loading dose). Peak and trough levels were monitored. Following the co-adminstration, plasma levels of digoxin were measured by radioummunoassay up to 24h post-dosing. In addition, standing and lying blood pressure and pulse rates were measured and 12-1ead ECG's obtained. Comparable steady state digoxln concentrations w e r e obtained immediately prior to the co-admlnlstratlon with lacldlpine and placebo (0.51 • O.12ngml- l and 0.51 • O.13ngml-l). Statistical analysis of the digoxin AUCo_24h values showed there to be no signlficant differences between lacidlplne administration and placebo (18.16 • 2.85nghml-] and 17.76 • 3.15nghml- l ) with the power being greater than 99% to detect a 25% difference. Cmax was significantly increased by 34% to 1.64 • O.44ngml- l following dosing with lacidipine (pO.05) in Cmin (0.48 • O.Ingml- l ) and tmaX (I.5 • 0.6h). The three fluctuation parameters, Cmax - Cmln, Cmax Cmln/Cav and Cmax - Cmln/Cmin were all significantly higher (p
Pharmacokinetie and/or pharmacodynamic interactions between digoxin and epanolol (ICI 141,292, VisacorR), a B1-selective adrenergic blocker with partial agonism, were studied. Ten healthy male volunteers (23-29 years) took digoxin orally for 2 weeks (day I : 0.75 mg; day 2 : 0.5 mg; from day 3 on : 0.375 mg); concomitantly, in a double-blind, randomized cross-over manner, either oral epanolol (200 mg) or placebo were taken for one week each. Measurements were done on days 7 and 14. The digoxin plasma concentration-time profiles from 0 to 12 hours on the last day of both treatment periods, were similar, with trough and peak levels of 0.87 + 0.08 ng/ml (mean l SEM) and 2.46 + 0.16 ng/ml during administration of epanolol, and 0.84 ~ 0.07 ng/ml and 2.62 + O.13 ng/ml during administration ~f placebo. Digoxin r~nal clearance was lower during epanolol treatment (116.O + 11.9 ml/ min, n = 8 because of incomplete urine collect~on in 2 volunteers) than during placebo treatment (141.O + 12.5 ml/min) but the difference was not significant. Systolic time intervals, corrected for heart rate, were : DIG. + PLACEBO DIG. + EPANOLOL QS21 513 + 4 503 + 4* LVETI 393 T 4 391T 3 PEPI 119 ~ 3 112 T 4** PEP/LVET 0.304 ~ 0.008 0.286 ~ 0.011"* * p < 0.05; ** p < 0.01 (ANOVA + t-test) -No p~armacokinetic interaction was found and the lower PEPI during administration of epanolol indicates that epanolol does not interfere with the positive inotropic action of digoxin. Heymans Institute of Pharmacology, University of Gent, De Pintelaan 185, B-9000 Gent, Belgium * Research Associate of the National Fund for Scientific Research

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INVESTIGATION OF POSSIBLE KINETIC INTERACTIONS O F A NIN POSITIVE INOTROPIC DRUG, ADIBEq~DAN, AND DIGOXIN E.v.M~l]endorff~ W ~ Akpan~ G. Neugebauer 9 healthy male volunteers received 0.75mg digoxin/day (D) p.o. for 3 days and from day 4 to 17 0,375mg D/day in order to initiate and maintain steady state conditions. From day ]0 to 16, the new orally active positive inotropic substance adibendan (A) was added, 5mg b.i.d., starting and ending on day 9 and 17, resp. with a single oral dose. On day 8 the kinetics of D, on day 9 and 17 the kinetics of D and A were studied. Concentrations of D were determined by RIA, those of A were determined by H P L C w i t h fluorom, detection. N o n - c ~ p a r m e n t a l kinetic parameters were derived.

INFLUENCE OF THE~-GLUCOSIDASE-INHIBITOR MIGLITOL ON THE STEADY STATE PHARMACOKINETICS OF DIGOXIN IN HEALTHY VOLUNTEERS H. Weber, R. Horstmann, K.-D. R~msch, W. Wingender, H. Schmitz and J. Kuhlmann e~-Glucosidase-inhibitors like Miglitol (BAY m 1099, M) have been shown to be valuable tools in lowering postprandial glucose levels in diabetic patients. To assess possible influences of M on the pharmacokinetics and pharmacodynamic effects Of digoxin (D) two different doses of M were administered to i0 healthy male volunteers (23-38 years) treated with D. After a loading dose of 0.6 mg beta-acetyldigoxin o.d. for 3 days a dose of 0.3 mg o.d. was given before breakfast on days 4-22, M (50 mg t.i.d, or I00 mg t.i.d.) was administered before the meals on days 9-15 or 16-22, respectively. In the morning of the last 3 days of each treatment HR, RR, stroke volume (by Doppler ultrasound) and D plasma levels (by RIA) were determined before drug intake. Renal clearance of D was calculated. Statistical evaluation was carried out by analysis of variance. Kinetic results for D (gecm. means, geom. sd; n = i0; *p~0.05):

Day .... Cmax [ng/mlJ tma x [h] AUC [ngxh/ml] t l / 2 [h]

Adihendan 9 17 2.49 2.63 7.5 ].0 ].2.25 12.62 4.43 7.27*

I .... Digoxin t 8 9 2.]--~-f-2.---.'.~ I 1.0 0.5 121.19# 20.79# l

17' 2.24* 1.0 17.55.#

Medians; statistical ccmparison with the 1 st day: * p < 0 . 0 S ; # = AUC 0.t e Although the AUC for D is about 15% lower on day 17 than before, the amounts in urine are not different on each day. Therefore it is concluded that A does not relevantly influence the kinetics of D. The kinetic data of A do not change significantly with the duration of administration, except for the half,life, which is about 2 times longer. A similar finding has been obtained in a previous study with A alone over 9 days in healthy volunteers. So there is no relation with D admini st rat ion. Beehringer Nannheim GmbH, Klinische Pharmakologie, Sandhofer Str. 116, D-6800 Mannheim 31

Treatment C~ (ng/ml) A~urine (pg/24h) ~ren ~ml/min/kg)

D 0.813, 1.25 251.2,1.16 2.965,1.29

D4M (50) 0.662, 1.41" 202.6, 1.30" 2.938, 1.36

D4M (i00) 0.586, 1.35" 169.5, 1.26" 2.775, 1.39

The slight reduction of D steady state plasma levels under M (19 % under 50 mg t.i.d, and 28 % under I00 mg t.i.d.) and of the daily renal excretion of D may be explained by a slight dose dependent impairment of D absorption induced by M. No changes in HR and RR but a slight increase in SV could be observed under D. Additional treatment with M did not induce further changes. Therefore, the influence of M on the pharmacokinetics of D does not appear to be of clinical relevance. Bayer AG, Pharma-Forschungszentrtlm, Institut for Klinische Pharmakologie, D-5600 Wuppertal 1

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A CLINICAL PHARMACOLOGICAL STUDY OF CHLORTENOXICAM AND DIGOXIN INTERACTION M. Ravic, I. G. Sales and P. Turner It has been found that some drugs concurrently used may interact with digoxin and precipitate toxic reactions. We investigated whether chlortenexicam, a novel non-steroidal anti-inflammatory drug (NSAID) given together with digoxin affects its pharmaeokinetics. Twelve healthy volunteers of either s e x , aged 18-45 years received 0.25 mg digoxin orally once daily for 25 days. Blood samples were collected during the study. A pharmacokinetic profile of digoxin over 24 hours was estimated on days ii and 25 , when a steady state had been achieved. Chlortenoxicam was given orally from day 12 to the end of study in a dose of 4 mg twice daily. A pharmacokinetic profile of chlortenoxicam over 12 hours was estimated on the day prior to the beginning of the study and on the last day. The levels of both drugs were followed during the study to avoid possible zntexication if a positive interaction ocurred. Plasma concentrations of digoxin and chlortenoxieam were determined by RIA and HPLC respectively. Pharmacokinetic parameters for both drugs were calculated using a two-compartment model. We calculated AUC, tmax, Cmax, tl/2, Vz, CI, ka and elimination rate constant. During the study both drugs were well tolerated without any side effect. There were no significant statistical differences between obtained pharmacokinetic parameters of both drugs given alone or together. There was no evidence of pharmacokinetic interaction between chlortenoxieam and digoxin in this study. St.Bartholemew's Hospital, Clin. Pharmacol. Dept., West Smithfield, London ECIA 7BE, U.K.

STUDY OF THE INTERACTIONS OF PROCAINAMIDE AND N-ACETYLPROCAINAMIDE IN MAN. C. Funck-Brentano, R. T. Light, G. M. Wright, D. M. Roden, R.L. Woosley. Procainamide (PA) and its main metabolite, N-acetylprocainamide (NAPA) have different electrophysiologic properties, antiarrhythmic effects and pharmacokinetics. Both compounds are actively secreted by the proximal tubule of the kidney and might compete for this route of elimination. Moreover, one might expect the block of sodium channels by PA, an inactivated channel blocker, to be enhanced by co-administration of a drug, such as NAPA, that prolongs action potential duration. We conducted a study to assess whether NAPA alters PA pharmacokinetics and activity in man. Ten patients with frequent ventricular arrhythmia received intravenous infusions of PA alone (10mg/min during 4h), of PA (as above) +NAPA (pre and 24h during PA), and of NAPA alone (as above), at least 48h apart. NAPA was infused to reach a stable pseudo-equilibrium plasma concentration of 8.4+2.1t~g/ml (mean• NAPA increased PA t%r from 4.6:~0.7h (mean• to 5.7:~!.2h (P<0.01). NAPA tendcd to dccrease PA total clearance and fractional urinary excretion. The fall in PA total clearance or urinary excretion in the presence of NAPA was more pronounced when the initial value of the corresponding parameter in the absence of NAPA was high (r=0.77 and r=0.89 respectively, both P<0.01). PA prolonged both QRS and QTc intervals on the ECG whereas NAPA only prolonged QTc. NAPA did not significantly alter PA-induced QRS prolongation and antiarrhythmic effect. However, as shown by the analysis of the individual concentration vs. effect curves and of QTc variations over time, NAPA potentiated PA-induced QTcprolongation. Conclusions: 1) NAPA prolongs PA t89 , 2) PA elimination is reduced by NAPA in patients with a high initial PA clearance, 3) NAPA may alter PA pharmacologic actions but does not appear, under our study conditions, to potentiate the antiarrhythmic efficacy of PA, Unite de Pharmacologie Clinique, H6pital Saint-Antoine, 184 rue du Faubourg Saint-Antoine, 75012, Paris, FRANCE.

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NON-INTERACTION OF THE ~ C O K I N E T I O S OF BISOPROLOL (BISO) AND HYDROCHLOROTHIAZIDE (HCTZ) G.Leopold 1, G.G, Belz 2, W.UngethUm1, K , B r e i t h a u p t z,

T H E O P H Y L L I N E A B S O R P T I O N IS R E D U C E D BY T H E CALCIUM ANTAGONIST FELODIPINE R. D a h l q v i s t , B. B i l l i n g a n d T. B r a t e l P r e l i m i n a r y d a t a i n d i c a t e d r e d u c t i o n in t h e o p h y l l i n e s t e a d y s t a t e c o n c e n t r a t i o n in a f e w of our patients when felodipine therapy was started. M e t h o d s . T e n h e a l t h y s u b j e c t s r e c e i v e d 141 m g anhydrous theophylline orally 8-hourly for 4 days; t h e n 5 m g f e l o d i p i n o r a l l y 8 - h o u r l y f o r 6 d a y s a n d t h e n t h e c o m b i n a t i o n of t h e t w o d r u g s f o r a n o t h e r 4 days. P l a s m a c o n c e n t r a t i o n s o f theophylline and felodipine were determined during a dosage interval the last day of each t r e a t m e n t p e r i o d . T h e o p h y l l i n e a n d its m e t a b o l i t e s w e r e d e t e r m i n e d in u r i n e . Results. Theophylline plasma AUC was reduced by 18% (p<0.01) a n d t h e t o t a l r e c o v e r y in u r i n e o f theophylline-derived products was similarly reduced during felodipine co-treatment compared to theophylline treatment alone. The metabolic a n d r e n a l c l e a r a n c e s of t h e o p h y l l i n e r e m a i n e d unchanged. Pelodipine pharmacokinetics remained unchanged during co-treatment with theophylline. Conclusion. Felodipine significantly but to a moderate extent lowered theophylline steadystate concentration by interfering with it's absorption while theophylline metabolism was u n c h a n g e d . T h e c l i n i c a l c o n s e q u e n c e s w i l l in most instances be minor. D e p t of C l i n i c a l P h a r m a c o l o g y , H u d d i n g e U n i v e r s i t y H o s p i t a l , S - 1 4 1 86 H u d d i n g e , S w e d e n

S.Longerich z, S. Simane I end W. Winkler I The objective of the study was to demonstrate at steady state the pharmacokinetic non-interaction of the new antihypertsnsive combination BISO + HCTZ. In a randomized double blind, three way cross-over study with 18 healthy volunteers (9 male) the pharmacokinetics of the fixed combination BI$O + HCTZ were compared with those of BISO and HCTZ administered separately. The d a i l y dosage o f 10 ms BISO and 25 mg HCTZ, s e p a r a t e l y or in combination, were ingested 30 min before b r e a k f a s t f o r 7 days in the three different medication periods, which were separated by washout periods of 7 days duration. The revised declaration of Helsinki was observed, due ethical review and written informed consent were obtained. The time-courses of the plasma concentration of unchanged BISO and/or HCTZwere determined during the seventh day of each medication period by specific HPLC-methods. Target parameters and results C~ z SD) R = Reference (=mono), T = test (=combination): Bl~ HCTZ .......................................... (R) (T) (R) (T) ............................................................. AUC%, [ n g . h / m l ] 942 Z 69 1035 • 281 1069 • 367 1196 t 289 C~

[ng/mt]

39.2•

43.1•

44.5•

49.8•

C~x

[ng/ml]

75.7•

84.1•

177.6•

205.0•

t ~ x [h] 1.69_+0.25 1.64_+0.72 2.22_+0.77 2.0_+0.82 ............................................................. AUC~'* 1.10 (1.0 - 1.19) 1.12 (1.01 - 1.22) ms~ Cma 1.11 (1.03 - 1.19) 1.15 (0.95 - 1.36) ............................................................. * Assessment of relative bioavailability (T/R ratio, geom. mean, ANOVA, 95 9 confid, interval, normal distribution) Conclusion: No clinically relevant interaction of the pharmacokinetics of bisoprolol and HCTZ. I) Preclinical and Clinical Drug Development, E. Merck, P.O.Box 4119, 0-6100 Darmstadt, FRG 2) ZeKaPha, Alwinenstr. 16, D-6200 Wiesbaden, FRG

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INVESTIGATION OF THE INFLUENCE OF CAFFEINE ON THE PHARMACOKINETICS OF THEOPHYLLINE.

THE ADSORPTION OF TIIEOPHYLLINEANDPHENyTOIN CONTAINING PRODUCTS

F.A.E. Sortie1, J. Dingemanse1. J.H.G. Jonkman 1. H. Staudin~,er2. V.W. Steiniiansz The aim of this open, two-way crossover study was to investigate the pharmacokinetics of theophylline in eight healthy young adult volunteers after intravenous infusion with and without concomitant administration of caffeine. During each of the two study periods of 8 days each, a total of 1200 mg of anhydrous theophylline was administered as a rapid loadiag infusion followed by a constant rate infusion over the 24-h interval starting at 08.00 h on day 6, in order to approximate a constant plasma concentration during the infusion. Is one of the study periods 300 mg of caffeine, t.i.d., was administered orally as immediate release 50 mg tablets at 08.00 h, 14.00 h and 20.00 h from day 1 up to 14.00 h on day 8. Plasma concentrations of theophylline and caffeine were determined before dosing at 08.00 h on day 1-6 and frequently during the 60-h interval after 08.00 h on day 6. Concentrations of theophylline and (main) metabolites of theophylline and caffeine, via. 1-methylxanthine, 1-methyl uric acid and 1,3dimethyl uric acid were also determined in urine collected during this interval. Results showed an increase of about 23% iu average theophylline plasma concentration during the 1-24 h interval after the start of the infusion following concomitant administration of caffeine. The area under the theophylline plasma concentratios vs. time curve up to 60 h after the start of the infusion showed an increase of about 38%. The Varea of theophylline seemed rather unchanged by the administration of caffeine. The cumulative urinary excretion profile of 1-methyl uric acid and 1-methylxanthine did not reach a plateau value during administration of caffeine, thus suggesting a capacity limiting factor in the formation of these metabolites. Despite the complicating factors due to the mutual interference of theophylline and caffeine metabolism and elimination, the reduction in apparent total body clearance of about 28% and the prolonged apparent elimination half-life (about 46%) of theophylline during concomitant administration of realistic amounts of caffeine indicated a pronounced influence on theophylline pharmaeokinetics. 1 2

Pharma Bio-Research International B.V., P.O. Box 147, 9400 AC Assen, The Netherlands Hyk Gulden Pharmaceuticals, P.O. Box 6500, D-7750 Koustanz, WestGermany.

BY CHARCOAL

J.C. McElnay, P.W. Wardlow and P.F. D'Arcy Several herbal products containing charcoal are available without prescription in the U.K. The aim of the present study was to examine whether the charcoal present in these products could decrease the gastrointestinal absorption of the two model drugs, theophylline and phenytoin. Two herbal products were studied namely Lanes Charabs (CR Lane Health Products Ltd. England) and Potter's Charcoal Tablets (Potter's Herbal Supplies Ltd. England). The adsorption by these products was compared with two commercially available activated charcoal powders (Acticarbone L405, British Ceca Company, England and activated neutralised charcoal, Sigma Chemical Company, England). The influence of caffeine on theophylline adsorption was also examined. Prior to use the herbal tablets were powdered and passed through a 180~m sieve. Theophylline and phenytoin adsorption was examined in vitro by incubating the drugs (37Oc;30 min;n~5) in aqueous solution at charcoal: drug concentration ratios ranging from 0 to 12.0. After centrifugation drug concentrations in the supernatent were measured using HPLC. Acticarbone at a concentration ratio of 12:1 resulted in 100% adsorption of both theophylline and phenytoin. The corresponding values for the Sigma activated charcoal was 94% and 83%. Caffeine was shown to compete with theophylline for binding sites. Drug adsorption by the powdered herbal products was negligible; the maximum amount adsorbed was only ii.5% (theophylline). The results of the present investigation indicate that although both drugs were extensively adsorbed by the commercial activated charcoals, the charcoal present in the herbal products had little adsorptive power. These latter products are therefore unlikely to enter into clinically significant drug absorption interactions with phenytoin or theophylline. School of Pharmacy, The Queen's University of Belfast, Belfast BT9 7BL, Northern Ireland.

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INHIBITION OF THEOPHYLLINE METABOLISM BY 8-METHOXYPSORALEN: IN VIVO STUDY IN HUMANS. G. Aoseloff. D. Sheoard. M. Chambers. S. Nawoot. N. Gerber and 15. Mavs. 8-methoxyl~soralen (8-MOP), a furocoumarin used to treat psoriasis, vitiligo, and cutaneous T-ceU lymphoma, has been shown to be a potent inhibitor of drug metabolism in humans. This study was designed to investigate further the inhibitory effects of this compound on drug metabolism. Three healthy, nonsmoking, male volunteers in a randomized crossover study received 600 mg oral, plain uncoated, rapid-release theophylline (THEO) either alone or one hour after 1.2 mg/kg Oxsoralen (oral 8-MOP). Timed blood samples were collected during a 48-hr period, and plasma (1.0 mL) was analyzed by a specific I-IPLC assay to quantify THEO. Subjects were given one week between phases of the study. No significant change in the peak plasma concentration of T H E O or the time to reach peak concentration was observed. T 1/2 of T H E O increased from 6.2, 5.9, and 13.1 hrs for subjects receiving T H E O alone, to 13.7, 8.4, and !6.7 ~ s respec~vely for those who-received 8-MOP prior to THEO. AUC ( u g . h r / m L ) increased from 205, 151, 10ll stmJE~T I and 375, to 604, 266, and 540 while clearance (mL/min) decreased from r \ --'~,.~. 0.74, 0.74, and 0.34, to "'-.% ~.~. 0.25, 0.42, and 0.23 respectively. We conclude that 8-MOP administered acutely inhibits T H E O metabolism in humans.

THE INTERACTION OF ALLOPURINOL AND HYDROCHLOROT H I A Z I D E . P A R T I. U R I C A C I D M E T A B O L I S M IN N O R M A L SUBJECTS DURING CHRONIC INGESTION OF ALLOPURINOL, WITHOUT AND WITH ADDITION OF HYDROCHLOROTHIAZIDE L 6 f f l e r W, L a n d t h a l e r R, W a l t e r - S a c k I, Z611ner N Medizinische Poliklinik der Universit~t Mdnchen, Pettenkoferstr. 8a, D - 8 0 0 0 M ~ n c h e n 2 Abteilung Klinische Pharmakologie der Medizinischen Universit~tsklinik, Bergheimerstr. 58, D-6900 Heidelberg

-

8

~

15 24 32 TIME (MR)

40

48

Dept. of Pharmacology, The Ohio State University, College of Medicine, Columbus, Ohio 43210 USA

W e s t u d i e d i n t e r a c t i o n s of a l l o p u r i n o l (ALLO) and hydrochlorothiazide (HCT) in s e v e n h e a l t h y m a l e v o l u n t e e r s , a g e 22 - 28 years. T h e y t o o k a semisynthetic, isoenergetic formula diet with a d d i t i o n of r i b o n u c l e i c acid, 2g/day, f o r 24 days. ALLO, 300 m g / d a y , a n d HCT, 50 m g / d a y , w a s g i v e n t h r o u g h o u t the s t u d y a n d f r o m d a y 11 - 21, r e s p e c t i v e l y . B l o o d w a s d r a w n in t h e m o r n i n g in the f a s t i n g s t a t e a n d 24 h u r i n e s w e r e c o l l e c t e d t h r o u g h o u t t h e study. P l a s m a l e v e l s of A L L O a n d oxypurinol (OXY) a r e r e p o r t e d in P a r t 2 of t h i s coraraunication (de V r i e s et al.). P l a s m a u r i c a c i d (UA) w a s 4 . 4 + 0 . 5 m g / d l in t h e s t e a d y s t a t e d u r i n g A L L O a l o n e a n d i n c r e a s e d toa m a x i m u m of 5 . 3 + 0 . 8 m g / d l a f t e r 6 d a y s of a d d i t i o n a l H C T (p 0.05). T h e r e a f t e r , p l a s m a U A d e c r e a sed to 4 . 8 + 0 . 9 m g / d l (21 days, l a s t d o s e of HCT) a n d w a s b e l o w c o n t r o l v a l u e s 4 d a y s l a t e r (4.2~ 0.6 m g / d l ) . C h a n g e s in r e n a l e x c r e t i o n of U A were less pronounced with aslight reduction occ u r r i n g a f t e r a d d i t i o n of HCT. R e n a l c l e a r a n c e of U A d e c l i n e d w i t h i n c r e a s i n g a n d i n c r e a s e d w i t h f a l l i n g p l a s m a levels. C r e a t i ~ i n e c l e a r a n c e did not change significantly. It w o u l d a p p e a r t h a t p r o n o u n c e d c h a n g e s of U A m e t a b o l i s m i n d u c e d b y H C T are of r a t h e r l i m i t e d d u r a t i o n , o t h e r f a c t o r s m a y be c o n t r i b u t o r y i~ c a s e s w i t h c o n s t a n t l y e l e v a t e d p l a s m a UA.

A 264

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T H E I N T E R A C T I O N OF A L L O P U R I N O L A N D H Y D R O C H L O R O T H I A Z I D E . P A R T 2 . P L A S M A C O N C E N T R A T I O N S OF A L L O PUR!NOL AND OXIPURINOL DURING ORAL ADMINISTRAT I O N O F A L L O P U E I N O L TO N O R M A L S U B J E C T S , W I T H O U T A N D W I T H A D D I T I O N OF H Y D R O C H L O R O T H I A Z I D E .

INTERACTION OF LITHIUM AND NATRIURETIC DRUGS. S. Freestone, R.F, Jeffrey and M.R. Lee The use of lithium (Li) clearance as a marker of sodium delivery from the proximal renal tubule assumes that Li does not affect tubular sodium handling. We have studied the effect of Li on the renal actions of Y-glutamyl-L-dopa (gludopa) and atrial natriuretic peptide (ANP) in healthy men. Subjects were studied on 2 occasions at least one week apart; they took a normal diet and for the ANP study received a supplement of 100 mmel Na for 2 days. At 22.00 h on the evening before study they took lithium carbonate 750 mg or placebo in random order. On the next day after a baseline period i.v. infusions of gludopa 25 l z g / k g / m i n for 90 rain (n=7) or ANP 22.5 n g / k g / m i n for 60 rain (n=8) were given. In both studies baseline sodium excretion was higher after Li (gludopa study 0.27 --- s.d. 0.10 v 0.18 -+ 0.08 ~tmol/min, p < 0.01; ANP study 0.36 + 0..08 v 0.28 • 0.07 ~mol/min, P < 0.05). Baseline plasma renin activity (PRA) was also higher (gludopa study 2.38 -+ 0.98 v 1.40 -- 0.98 ng AI/ml/h, p < 0.05; ANP study 1.38 -+ 1.09 v 0.94 -+ 0.57 ng A l / m l / h ) . On the control days a significant oatriuresis occurred with both gludopa (0.44 +_ 0,21 pmol/m~,'~ ~nd ANP (0.47 • O !O .ur~ol/mln'~ After Li the increase in sodium excretion was significantly attenuated (gludopa study 0.10 -+ 0.11 v 0.26 -~ 0.17 pmol/min, P < 0.05; ANP study 0.05 • 0.10 v 0.19 +- 0.15 lzmol/min, P < 0.01). Suppression of PRA with both gludopa and ANP was of similar magnitude on the control day and after lithium p r e t r e a t m e n t . The mean initial serum lithium concentrations were 0.29 _+ 0.09 retool/1 (gtudopa study) and 0.27 • 0.05 retool/1 (ANP study), In preliminary experiments the eatriuretic effect of frusemide 30 mg i.v. was not attenuated by lithium pretreatment. As Li attenuates the natriuretic effect of both gludopa and ANP the Li clearance method is not suitable for the investigation of the site of action of natriuretic agents. University Department of Clinical Pharmacology, Royal Infirmary, Edinburgh, UK.

The interaction of allopurinol (ALLO) with hydrochlorothiazide (HCT) w a s s t u d i e d in s e v e n healthy subjects. Aim of our work was to m e a s u r e the p l a s m a c o n c e n t r a t i o n s of A L L O a n d its m a i n a c t i v e m e t a b o l i t e o x y p u r i n o l (OXY) b y H P L C and to c o m p a r e p h a r m a c o k i n e t i c parameters during the different treatment periods. The e x p e r i m e n t a l design, c l i n i c a l d a t a a n d the u r i c a c i d c l e a r a n c e s w e r e d e s c r i b e d b y W. L 6 f f l e r et al., P a r t i. B o t h d r u g s w e r e a d m i n i s t e r e d o n c e daily, ALLO, 300 mg d u r i n g d a y s 1-24, HCT, 50 mg f r o m d a y s ii to 21. V e n o u s blood samples were obtained at v a r i o u s time intervals. For the present study data from day I0 (ALLO alone; t r e a t m e n t !; TEl) a n d d a y 21 (ALLO p l u s HCT; t r e a t m e n t 2;TR2) w e r e a n a l y s e d . For ALLO, the a r e a s u n d e r the p l a s m a c o n c e n t r a t i o n time curve f r o m 0-24 h (AUC) and the p l a s m a e l i m i n a t i o n h a l f lives (TI/2) w e r e not s i g n i f i c a n t l y different between both treatment periods ( W i l c o x o n test; significance at p~ 0.05). OXY with a l o n g e r T I / 2 t h a n the p a r e n t compound s h o w e d no s i g n i f i c a n t differences between TEl and T R 2 of the AUC, T I / 2 a n d Css c o n c e n t r a t i ons at the e n d of the d o s a g e i n t e r v a l . Conclusion: No i n t e r a c t i o n s between ALLO and H C T w e r e f o u n d by a n a l y s i n g p l a s m a AUC, TI/2 and Css d a t a for A L L O and OXY. Abteilung Klinisehe Pharmakologie der Medizinischen Universit~tsklinik Heidelberg, Bergheimerstr. 58, D - 6 9 0 0 H e i d e l b e r g , FRG.

PP 11.27

PP 11.25 INTERACTION BETWEEN LITHIUM RENAL ELIMINATION STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDa)

AND

NON

J.L. Imbs~, 3.M. Danion 2, M. Earthelmebs I, M. Welsch I, L. Singer The use of certain NSAIDs in lithium treated patients can induce an increase in serum lithium level together with a fall in renal lithium clearance linked with an increase in tubular reabsorption of the metal. We described thisinteraction i0 years ago, simultaneously with J.C. Fr61ich et cell.. Since that time, it as been widely documented : elometacin, diclofenac, ibuprofen, indometacin, ketoprofen, mefenamie acid, niflumic acid, oxyphenbutazone, phenylbutazone and piroxicam have been shown to be responsible for an interaction with lithium clearance inducing a rise in serum lithium concentration. It is important to consider that the interaction has been described for at least one member of each NSAIDs family with the exception of salicylates. In animal, benoxaprofen did not interact with lithium clearance. In patients, sulindac has been reported not to reduce urinary lithium elimination hut, in rat experiments, we demonstrated a reduction in lithium clearance with this NSAID and its active metab61ite, desoxysulindac. An inhibition of renal cyclo-oxygenase was thought to be responsible for the increase in tubular reabsorption of lithium. Since aspirin, at doses reducing the urinary level of prostaglandins, did not reduced the lithium clearance neither in healthy volunteers nor in animal experiments, this h y p o t h e s i s can no l o n g e r be maintained. The mechanism of the interaction remains unknown. iCentre R@gional de Pharmacovigilance Alsace, CHRU et URA DO 589 CNRS, Universit@ Louis Pasteur, 67000 Strasbourg; 2Service de Psychiatrie, CHRU, 67000 Strasbourg, France.

ATTENUATION OF FUROSEMIDE-INDUCED DIURESIS BY SUCRALFATE F.O. MOller, I . Reyneke, H.K~L. Hundt and H.G. Luus AIM To determine i f , and to what extent, concomitant ingest i o n of sucralfate and furoaemide a f f e c t the l a t t e r drugs dynamics (diuresis) and urinary excretion kin e t ics. METHOD Nine healthy maIe volunteers participated in a randomised, 3-way cross-over study (Latin square design). The t r e a t ments consisted of: A = furosemide 40mg (Lasix); B = sucralfate lg (Ulsanic); C = furosemide 40mg and sucralf a t e lg. Food and f l u i d intake were s t r i c t l y controlled on t r i a l days. Fractionated urine samples were c o l l e c t ed hourly f o r 6 hours and subsequently two-hourly u n t i l 10 hours a f t e r drug ingestion. Urine volumes, e l e c t r o l y t e and furosemide concentrations were determined, Treatments were separated by a washout period of 7 days. RESULTS Furosemide-induced diuresis lasted for 3 hours. Mean (SD) urine volumes (ml) for treatments A and C (O-3h) were 1296(379) and 846(390), respectively. Mean (SD) urinary excretion of furosemide (ug) for treatments A and C (O-3h) were 12016(3153) and 5589(2065), respectively. The corresponding O-lOh values (ug) were 16912(2962) and

9263(2D34). CONCLUSION Sucralfate, which has been found to attenuate the absorpt i o n of phenytoin and digoxin, s i g n i f i c a n t l y attenuates furosemide-induced diuresis; secondary to a reduced rate of urinary excretion of furosemide. This i n t e r a c t i o n could possibly be avoided by allowing a time lapse of about 2h between ingestion of the two drugs. Dept. of Pharmacology, University of the Orange Free State PO Box 339, Bloemfontein 9300, South Africa

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PP 11.30

VERAPAMIL(V) DISPOSITION DURING INHALATIONAL ANESTHESIA: ROLE OF HEPATIC BLOOD FLOW P. Wouters, M-F. Doursout, A. Varughese, S. Kashimoto, J.E. Chelly, and R.G. Merle Since V is a drug with high hepatic extraction ratio, its elimination characteristics depend on total hepatic blood flow (THBF). We previously demonstrated that inhalational anesthetics significantly reduce clearance of V in dogs. The goal of this study was to define the dependence of V clearance on THBF in the presence of inhalational anesthetics. Eight dogs were chronically instrumented with a sampling catheter in the aorta and pulsed Doppler flow probes around the hepatic artery and portal vein. During anesthesia with 1.2 MAC isoflurane (I) and halothane (H) respectively, 200 ug/kg V was administered intravenously over I0 min. Hepatic blood flow measurements and arterial samplings were performed before and I, 3, 5, I0, 15, 20, 30, 45, 60, 90, and 120 min and 3, 4, 5, and 6 h following the end of infusion. V plasma samples were analyzed using HPLC. Statistical comparisons were performed with ANOVA, followed by Student's t-test where appropriate. Arterial hepatic blood flow (AHBF), portal blood flow (PBF) and THBF (AHBF+ PBF) were similar during I and H. V did not alter hepatic blood flow. In contrast, clearance of V was significantly higher during I than H. We conclude that during inhalational anesthesia, clearance of V is not totally dependent on hepatic blood flow. Therefore, other mechanisms should be considered in the explanation of anesthetic-induced effects on V clearance.

INFLUENCE OF CIMETIDINE ON THE PHARMACOKINETICS OF NIMODIPINE IN HEALTHY VOLUNTEERS W. Wingendsr, K.-D. R~msch, J. Proeve and J. Kuhlmann Metabolic interactions are specifically important for those drugs undergoing extensive metabolism in the liver. Calcium antagonists of the dihydropyridine type are known to be predominantly eliminated by the route of biotransformation. Cimetidine affects the metabolism of many drugs due to its inhibition of the drug metabolising enzyme system of the liver. Kirch (Dtsch. med. Wschr. 108, 1757, 1983) firstly reported a significant elevation of nifedipine plasma levels in 6 healthy volunteers during concomitant administration of cimetidine and nifedipine. Since nimodipine, a 1,4-dihydropyridine derivative, is totally eliminated by biotransformation a metabolic interaction with cimetidine should be expected. 8 healthy volunteers were given 30 mg nimodipine t.i.d. for 6 days to reach steady state plasma levels. On day 7 of monotherapy the plasma concentration time course of nimodipine and metabolites was determined by gas chromatography. From day 8 to day 13 the dose regimen of nimodipine was continued and concomitantly 200 mg cimetidine t.i.d, and 400 mg cimetidine before sleep was administered. On day 1 4 the plasma concentration time profile of unchanged nimodipine and metabolites was determined. The co-administration of eimetidine increased the mean maximum nimodipine plasma concentration by about 50 % (20.4 ~g/l to 31.5 ~g/l) and the area under the curve by about 90 % (41.3 ~g*h/l to 77.9 ~g*h/l). The mean elimination half-life was increased by about one third whereas t remained almost unchanged. max The pharmacodynamlc parameters blood pressure, heart rate and ECG were almost unchanged during the study sequence. Bayer AG, Pharma-Forschungszentrum, Institut for Klinische Pharmakologie, D-5600 Wuppertal 1

H

AHBF (ml/min) 101+18 PBF (ml/min) 453556 THBF (ml/min) 551571 V Clearance (L/h) -P < 0.05, e = I versus H

H+V

104+19 439~46 540~56 24.052.5

I

95+15 533~72 673~77 --

I+V

92+14 519~76 659~75 28.5~1.9"

Dept. Anesthesiology, Baylor College of Medicine, 1Baylor Plaza, Houston, Texas, 77030, USA

PP 11.29 T H E E F F E C T OF C O N C O M I T A N T C I M E T I D I N E ADMINISTRATION ON STEADY-STATE BLOOD LEVELS OF D O X O F Y L L I N E IN S M O K E R S A N D N O N S M O K E R S . J. C o l q u h o u n , F. C a r u s o , R. V u k o v i c h Doxofylline (Dox), a n e w m e t h y l x a n t h i n e b r o n c h o d i l a t o r , w a s a d m i n i s t e r e d o r a l l y as 4 0 0 m g t.i.d. + c i m e t i d i n e (Cim) 800 m g q.d. i n 16 n o r m a l m a l e v o l u n t e e r s (II s m o k e r s ( S ) and 5 n o n s m o k e r s ( N S ) ) in an o p e n b a l a n c e d , 2-way crossover study with 7-day dosing periods. D o x b l o o d l e v e l s w e r e m e a s u r e d on D a y s 1-6 j u s t p r i o r to the 2nd d a i l y d o s e ( t r o u g h l e v e l s ) and on D a y 7 ( s t e a d y - s t a t e levels) at 15 m i n up to 48 h r a f t e r the s i n g l e m o r n i n g d o s e of D o x + Cim. T h e r e w e r e no s i g n i f i c a n t d ~ f f e r e n c e s in blood levels measured from Day 1 through Day 7 b e t w e e n the D o x a l o n e and D o x + C i m treatments. Pharmacokinetic parameters were: (~g/ml) (mean i SD) umax AUC Tmax Half-life Dox NS 18.4 253.4 1.4 h 7.6 h S 6.2 68.3 2.1 6.6 Dox + NS 15.8 205.0 1.5 6.5 Cim S 7.2 73.1 1.5 3.4 Mild. p o s s i b l y d r u g - r e l a t e d A D R s w e r e reported. We c o n c l u d e that u n l i k e t h e o p h y l l i n e , D o x b l o o d l e v e l s are n o t s i g n i f i c a n t l y a f f e c t e d by c o n c o m i t a n t a d m i n i s t r a t i o n of C i m in b o t h s m o k e r s and n o n s m o k e r s . ( S t u d y c o n d u c t e d at R i v e r v i e w C l i n i c a l S t u d i e s C e n t e r , Red Bank, NJ) Roberts Pharmaceutical Corporation, 6 I n d u s t r i a l W a y West, E a t o n t o w n , NJ 0 7 7 2 4

PP 11.31 ~Fr/TIVE

PI{%N~%fDKINETICS IN M~N: INTER~-TIC~

CIMETIDINE

J. Bcnde, H.R. Angelo, L.E. Pedersen, E. Nyqaard, T. Ramsing, J.P. Kampmann Cimetidine is a well known inhibitor of drug metabolism and renal secretion of a variety of drugs (Somogyi and Muirhead, Clin Pharmacokinet 1987; 12:321 ). Disopyramide is eliminated by hepatic metabolism and tubular secretion, and consists of two enantiomers with distinct kinetic and dynamic profiles. We therefore investigated for a possible interaction between cimetidine and the two stereoselective enantiomers of disopyramide. 150 mg disopyramide was given intravenously as a bolus injection to 8 healthy volunteers in a randomised cross over study before and after two weeks of treatment with oral cimetidJne 800 mg daily. Enantiomers of disopyramide and its major metabolite N-desisopropyldisopyramide were measured after extraction (Corre et al, J Chromatogr 1988; 450:211 ) and separation by using a ChromSep I0 cm Sperisorb CN analytical column (Chrompack) coupled in series with a chiral column, CHIRAL-AGP (Chro~rfech). The mobile phase consisted of 8 nM phosphate buffer, pH 6.0, containing 5.0% (v/v) 2-propanol and 0.07% (v/v) N,N-dimethylcotylamine; flow rate 0.7 ml/min. Results: Before treatment with cimetidine clearance values of the R isomer varied between 123 and 172 ml/min, significantly higher than clearance for the S enantiomer (64-88 ml/min). Volume of distribution varied from 67-94 1 and 40-52 i, respectively. No significant differences were observed concerning half-life (343,569 min). N o significant interaction was observed following oral treatment with cimetidine, indicating that no dosage adjustment of disopyramide is necessary when giving cimetidine concomitantly (in contrast to coadministration with liaocaine). Department of Anaesthesiology, KAS Herlev, Department Clinical Chemistry Bispebjerg Hospital and the Royal Danish School of Pharmacy, Copenhagen, Denmark. Department of Medicine P, Bispebjerg Hospital, Bispebjerg Bakke 23, EK-2400, Copenhagen NV.

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PP 11.34

PBARMACOKINETIC AND PHARMACODYNAMIC INVESTIGATION OF A POSSIBLE INTERACTIONOF ACARBOSE, A GLBCOSIDASE-INHIBITOR, WITH THE H2-ANTAGONISTRANITIDINE E.WOLKE l ) , M.SEIBERLING l ) , H.FRANKE l ) , A.R.BAUNACK2), G.SEIDEL 2). Since Acarbose {A) treatment most often will be a longterm treatment, a possible pharmacokinetic and pharmacodynamic interaction with the widely prescribed H2-antagonist Ranitidine (R) is of special importance. 12 healthy male volunteers, aged between 18 and 37 years, were admitted into a double-blind, randomized crossover study. In one session the subjects received 600 mg of A (3x2 tabl. of lO0 mg each) on day l and 400 mg (2x2 tabI. with breakfast and lunch) on day 2. Tablets were administered always at the beginning of the main meals. In the other session, the subjects received matching Placebo (P). In both sessions 300 mg of R were administered 2 h after dinner of flay I. Blood sampling for pharmacokinetics of R was performed until +22 h after R administration. In each session, the gastric acid secretion was measured using an intragastric electronic pN-monitoring system from 2 h prior to and until lO h after R administration. AUC, elimination h a l f - l i f e and the total clearance did not show any significant difference between R in combination with A or compared to P. O n l y the maximum plasma concentration of R was significantly higher estimated when given with P. During the el•177 phase, however, the corresponding plasma concentration could not be differentiated from each other. The gastric pN-profiles revealed no difference between R and A in comparison to R and P. Both drugs were well tolerated. I t can be stated that there were no c l i n i c a l l y relevant differences of the R plasma concentration curves and no pharmacodynamic interaction could be detected. l ) Biodesign, Institute for Clinical Pharmacology, Obere Hardtstr. 8-16, D-7800 Freiburg 2) Bayer, Pharma Research Center, Aprather Weg, D-5600 Wuppertal l

EVALUATION OF POTENTIAL QUINIDIN~ RANITIDINE PHAP$~ACOKINETIC INTERACTION A. Iliopoulou, A.Katsifi, D.Tsoutsos, E.Kostis, S.Moulopoulos. The effect of a single dose (S0 mg) of ranitidine (R) on the steady state pharmacokinetics of oral quinidine (Q) (600 mg for 3 days) was studied in 6 male patients with normal liver and renal function. A randomized crossover design with a 8 day washout period between treatments was used. Q concentrations were measured by immunofluorescence polarization assay in serial (12) serum samples obtained over the 30h period following the last dose. Two compartment and paired t-test analysis was applied. Mean area under the curve (AUC) and elimination half-life (T~) were 54.0• and 19.9• with Q alone and 68.5• wg/ml.h and 20.7• with Q plus R together (p<0.1, p<0.5). Peak concentrations (Cmax) and times to peak (T max) were not different (p>0.5) between treatments (average 3.0• and 1.6• respectively). Serum protein binding was mnchanged also. These data indicate no significant effect of ranitidine (enzyme inhibitor) on the steady state pharmacokinetics of quinidine as claimed for other H2-antagonists and despite our previous observation of potential pharmacodyrmmic interaction. Dept. of Clin. Therapeutics 'Zlexandra" Hospital, 80, Vas. Sol• Ave. Athens Greece. 115 28

PP 11.33

PP 11.35

THE EFFEcTS OF R~NITIDINE, METOCLOPROMIDE, _AND. ANiSOTROPINE METHYLBROMIDE ON THE, AVAILABILITY OF CEFs IN JA_mANESEHEALTHY SUBJECTS E~ Uchida , S. Koba~asbi, Y. ~ i j 9 , _M. Yamada, M. Hisaoka, K. Oguchi and H. Yasuhara Cefpodoxime Proxetil(CP) is a new oral cephalosporin, which itself has no antibacterial activity but is transformed to an active metabolite (R-3763) by nonspecific esterases in the intestinal wall. Two studies were carried out on the absorption of CP e/aploying two or three way cross-over design : I) Ranitidine(R;150 mg) was administered orally to 6 healthy male volunteers 1.5 hr before the dose of CP. Intra gastric pH was monitored through micro-pH-electrede for 6.5 hr after ranitidine treatment. 2) The effects of metoclopromide(MCP) and anisotropine methylbrc~ide(ATMB) were studied in 9 healthy male subjects. Serum concentration and cumulative urinary excretion of R-3763 were determined for assessing bioavailability. Results are as follows: i) R treatmentsignificantly decreased ka (from 0.957 • 0.052 to 0.612 • 0.030 I/hr ; p<0.05), Cmax (from 1.44 i 0.05 to 0.67 • 0.04 mg/L ; p<0.01), AUC (from 7.33 i 0.40 to 4.10 • 0.13 mg hr/L ; p<0.01), and the amount of urinary excretion ( 37.75 • 0.72 to 21.07 • 1.82 % ; p<0.01). This indicates that the absorption of CP is affected by the increased gastric pH probably due to delaying the dissolution of CP in the stomach. 2) No significant difference was found for pharmacokinetic parameters of R-3763 among groups of MCP, ATMB and control except for the amount excreted into urine between MCP (31.32 • 1.84 %) and ATMB groups (39.80 • 3.18%) ( p<0.05 ). From these results, a sufficient low gastric ~s and delayed gastric emptying time should he required for better absorption of CP in man. Department of Pharmacology, School of Medicine, Showa University, Shinagawa-ku, Tokyo 142, Japan

INFLUENCE OF ANTACIDS AS CONCOMITANTMEDICATION ON OFLOXACIN PHARMACOKINETICS IN HEALTHYVOLUNTEERS M. Bad• H. G. Eckert*, V. Malerczyk*, B. H. Meyer**, F. O. M~ller**, W. Niehsen* The absorption of quinolones may be affected by administration o f antacids. This study was performed to establ i s h the e f f e c t s of concomitant MaaloxK (magnesium hydroxide + aluminium hydroxide; MJ and Gastrobin R (magnesium t r i s i l i c a t e ; G) on T a r i v i d K ( o f l o x a c i n ; OFX) k i n e t i c s in 12 healthy subjects. Each subject received a single oral dose of 200 mg OFX on 3 study days, twice with and once without antacid (M - I sachet; G - 2x500 mg tabs); washout period: 7 days. The antacid was given 4 times d a i l y f o r 2 days before and once 24 h a f t e r OFX. Blood and urine were collected before OFX treatment and up to 24 and 48 h t h e r e a f t e r r e s p e c t i v e l y f o r OFX determination (HPLC). Standard safety pharmacology was also performed, The mean age was 21 yrs (19-25) and mean weight 75 kg (65-93). The following means (SD) were obtained f o r o f l o x a c i n : Variables

OFX + M

OFX + G

OFX

Cmax [mg/l] tma x [h] AUDo_28 [mg.h/l] Urin. recov. [mg]

0.62 1.9 3.54 74

1.61 1.3 6.69 125

2.40 1.1 9.40 168

(0.18) (1.0) (0.65) (10)

(0.55) (0.4) (1.52) (38)

(0.30) (0.4) (0.83) (12)

M and G both reduced absorption of OFX; M to a significantly greater extent. No drug-related adverse reactions were observed and safety examinations revealed no abnormalities considered to be drug related. * Hoechst AG, Clinical Research Department, Clinical Pharmacology, Postfach 800320, 6230 Frankfurt/Main; 80, FRG ** University of Orange Free State, Department of Pharmacology, 9300 Bloemfontein, South Africa

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PP 11.38

INHIBITION OF ANTIPYRINE METABOLISM BY CIPROFLOXACIN IN MAN K.K.C. Tan, M.C. Allwood and S. Shawket Ciprofloxacin is a 4-quinolone antibiotic which has been POstulated to inhibit cytochrome P-450 mediated theophylline metabolism since theophylline blood levels are increased in patients during co-administration of the two drugs (W.J.A. Wijnands et al., Br. J. olin. Pharmacol., 22, 677, 1986). Potentially significant interactions could occur between ciprofloxaein and other drugs which are metabolized by hepatic cytochrome P-450 enzymes and which possess narrow therapeutic margins. This study investigated the effect of ciprofloxacin on hepatic drug metabolism using antipyrine as a model drug. Six d r u g - f r e e non-smoking healthy male volunteers (age 26.5 -+ 5.2 and weight 69.3 • 7.9 (• s.d.)) were studied. Each subject received antipyrine on two occasions, after no treatment and on day 5 of a 6 day course of ciprofloxacin tablets 750mg twice daily. Fasting subjects were given antipyrine 500rag in 200ml water and 2ml saliva samples collected at 0, 1, 3, 6, 9, 12, 24, 32 and 48 hours after antipyrine administration. Urine collection was undertaken for 24 hours after antipyrine administration during ciprofloxacin treatment. Antipyrine and ciprofloxacin were measured by h.p.l.c. (M.W.E. Teunissen et al., J. Chromatogr., 278, 367, 1983; W. Gau, et al., J. Liq. Chromatogr., 8, 485-497, 1985). Antipyrine clearance was significantly decreased (paired t test; p<0.05) from 0.60 • 0.24 to 0.32 • 0.08ml/min/kg (• s.d.) during ciprofloxacin treatment. Ciprofloxacin treatment significantly prolonged antipyrine half-life from 9.5 • 1.9 to 15.6 • 4.4 hours (• s.d.) but there was no significant change in the volume of distribution of antipyrine. Urine 1 ciprofloxaein concentration measurements (430 -+ 217 mg 1- (-+ s.d.)) indicated good compliance with treatment. The results suggest that ciprofloxacJn is a potent inhibitor of hepatic eytoehrome P-450 enzymes. Clinical Pharmacology Unit, Level 2, F & G Block, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ

ASSESSMENT OF THE POTENTIAL INTERACTION BETWEEN KETOROLAC AND RACEMIC WARFARIN IN HEALTHY VOLUNTEERS $ T0on, B L Holt, L Aarons, M Rowland and R Bullinlham Ketorolac tromethamine (KT) is a prostaglandin synthetase inhibitor with indications for the treatment of post-operative pain. As anticoagulant therapy with warfarin may be initiated perioperatively, there exists a potential for interaction between the two drugs. A study (2-way crossover, double-blind) was undertaken in 12 (10 of whom completed) informed consenting healthy volunteers to assess the potential interaction. In each period K T (10mg) or matching placebo was dosed orally 4x daily for 12 days with a single 25rag oral dose of racemic warfarin being administered on day 6 of the regimen. There was a 14 day washout period between phases. Blood samples were taken over the 7 - d a y period post-warfarin dosing to facilitate assessment of the pharmacodynamics and pharmacokinetics of (R)- and (S)warfarin in plasma (stereoseleotive quantification by HPLC). The pharmacodynamic effect of warfarin was assessed by the area under the prothrombin time-time curve (AUCpT), maximum prothrombin time (PTmax) and the time to reach PTma x (tpTmax). Factor VII and Kaolin Cephalin Clotting Times (KCCT) were measured at baseline, 24 and 36h post-warfarin dosing as further indices of anticoagulant effect as were plasma betathromboglobulin (BTG) concentrations to assess platelet activation. Template bleeding time was determined at baseline and 36h post-warfarin as an overall measure of haemostasis. Concomitant ketorolac administration was found to produce no change in AUCpT (KT v placebo • sd; 3310• v 3243• PTma x (25.6 • 4.9 v 24.7• or tpTm (42.0• v 45.6• as compared to placebo. Whilst having n~Xeffect on Factor VII, K C C T or BTG, K T produced a significant prolongation of the template bleeding time (6.86 • 1.64 v 4.84• p = 0.019). Apart from a reduction in Cmax of both (R)- and (S)-warfarin ((R) 0.68• v 0.95• -1 p=0.054; (S) 0.68• v 0.83-+0.15mgL-1 p=0.026), K T h a d n o effect on the pharmacokineties of either enantiomerlCl/F; (R) 0.37 • v 0.34 -+ 0.08]Lh-1, (S) 0.58+0.21 v 0.50• -1 vZ/F; (R) 20.2• 2.88 v 17.7 • 3.49L, (S) 22.7• v 19.2_+3.36L). In conclusion chronically administered ketorolac had no major effect on the pharmacodynamics or pharmacokinetics of a single 25mg oral dose of racemic warfarin administered to healthy volunteers. Medeval, Coupland III Building, University of Manchester, Oxford Road, Manchester M I 3 9 P L UK.

PP 11.37

PP 11.39

HARFARIN REMOXIPRIDE INTERACTION

THE PHARMACOKINETIC INTERACTION OF NEW NSAID(480156-S) ON PROPRANOLOL, DIAZEPAM, WARFARIN ANDTOLBUTAMIDE IN ~IMAN. S.Kobavashi, E,Uchida, T.Ueda, K.Hamada, S.Iida, K.Oquchi, T.Oquma and H.Yasuhara 2-[4-(2-thiazolyloxy) phenyl] propionic acid(480156-S) is a new acidic nonsteroidal antiinflammatory and analgesic agent. Multiple dosing of 156-S markedly decreased the urinary excretion of the oxidized metabolites of 156-S, which suggested the reduction of hepatic drug oxidase acitvity in human by 156-S treatment. 156-S multiple dosing also significantly decreased the hydroxylation of ibuprofen and the N-demethylation of trimethadione, while slightly increased the u r i n a r y excretion 4hydroxyantipyrine and the urinary 6 B hydroxycortisol/cortisol ratio in human, respectively. From these results, the interaction in disposition of propranolol(PR), diazepam(DZ), w a r f a r i n (WF) and tolbutamide(TB) with 156-S were studied to determine the pharmacokinetie parameters of these drugs after multiple dosing of 156-S, respectively. The pharmacokinetic parameters of PR(40mg), DZ(5mg), WY(10mg) and TB(500mg) following oral administration with or without 156S(300mg, for 5 to 9 days) were studied in healthy male s~bjects, respectively. TI/2 and AUC of DZ(31.1• to 63.6• hr, 3613• to 5663 • 250~ ng.hr/ml), ~(37.0• to 87.8• hr, 45.8• to 108.2• mg. hr/l) and TB(7.2~1.1 to 43.4• hr, 672• 142 to 4206• mg-hr/l) were increased significantly by multiple dosing of 156-S, without chages of V/F's(1), respectively. These results of the markedly prolonged TI/2 of DZ, WF, TB with 156-S may indicate that the hepatic oxidative m e t a b o l i s m of these drugs were inhibited by 156-S and suggest that clinical important drug interactions m y occur with 156-S treatment. Department of Pharmacology, School of Medicine, Showa University, I-5-8 I~tanodai, Shinagawa-ku, Tokyo 142, Japan

M. Grind I, W. Yisak 2, S. Warringtonlt C. v Bahr2~ M. Rowland 3, S. Toon 3 and M. Murphy 1 Remoxipride (RM), a new selective D2-receptor antagonist with antipsychotic activity is extensively metabolised by the hepatic cytochrome P-450 system, as is the oral anticoagulant warfarin (W). The potential effect of RM on W was studied in 14 healthy male volunteers. Each received a single 25 mg oral dose of racemlc W alone and during a 7 day i00 mg bid oral regimen of RM. Plasma concentrations of R(+) and S(-)-Wwere determined by an enantlospecific HPLC assay. There was no significant change in any pharmacoklnetlc

parameters of W. Thus, for R(+)-Warfarin the mean (+SD) values in the absence vs presence of R M w e r e : Cma x 1.5+0.6 v s 1.5+0.6 mg/l -I, tmax 2.0+0.8 v s 3.0+1.6, AUC 30.9+6.1 v_ss 31.i+7.5 mg.h.l -I, and t% 41.4+6.8 v s 37.8+14.6 h. The values for S(-)-Wwere: Cma x 1.4+0.5 v_ss 1.3+0.4 mg/l -I, tmax 1.4+0.5 v_ss2.4+1,5 h, AUC 26.9+8.0 V S 27.4+7.2 mg.h.l -I, t89 41.0+24.4 v_ss26.7+10.1 h. The maximal prothrombin time (PTmax) , the time to reach

PTma x (tmax) and the AUCpT for W given alone and during RM treatment were 24.3+5.7 vs 23.5+4.6 sec, 56.9+26.9 vs 43.4+15.4 h, and 3180+453 vs--3167+447 sec.h, respectively.

This study indicates that RM has n o effect on the pharmacokinetics or pharmacodynamics of racemic W. iCharterhouse Clinical Research Unit, 91-93 Charterhouse Street, London ECIM 6HR, England 2Department of Clinical Pharmacology, Astra Research Centre, S-151 85 SSdert~lje, Sweden 3pharmacokinetic Department, Medeval, university of Manchester, Manchester MI3 9PL, England

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PP 11.42

M A C R O L I D E S AND CYCLOSPORINE INTERACTIONS: CLINICAL VALIDATION OF AN EXPERIMENTAL MODEL E.M. Billaud, R. Guillemain. N. Fortineau. C. Kreft-Ja'fs. C. Amrein, G. Dreyfus and JM Alexandre Cyclosporine (Cs), an immunosuppressive agent with concentration related nephrotoxicity, and Macrolides (MD) are known to be highly metabolized by the cytochrome P450 system. Therefore the association of these drugs may originate strong drug interactions. In vitro studies (Carlo et al) using human or animal hepatic microsomal fractions have shown that Troleandomycin (TAO), Erythromycin (E), Josamycin (J), Pristinamycin (P), Roxithromycin (R), but not Spiramycin (S), use the same P450 cytochrome isoenzyme as Cs. They have also shown that their potential interaction profile was from strong with TAO to insignificant with R. In clinical practice, TAO is seldom used, but several cases of drug interaction between Cs and E have been reported, accompanied by an increase of Cs concentrations (up to six times) and nephrotoxicity. We have reported two cases of less severe interaction with J. P, a related MD molecule, is known to interfere in a similar way. In the light of in vitro resuhs and clinical case reports, we were interested in testing the possibility of interaction of Cs with S and R . Two parallel studies were conducted in heart transplant recipients with stable plasma Cs concentrations (trough level TO 150-250 ng/ml). Concomitantly to Cs, for 10 consecutive days, 6 patients were given 2xlg/day of S and 8 others patients received 2x150 rag/day of R. Cs and Creatinine levels were measured twice weekly before, during and after MD administration. No changes in Cs levels were seen in the S group. In the R group, we observed a minor but not statistically significant increase (TO + 28%). This variation must not be considered as clinically meaningful, as compared to E and I Furthermore, as in the case of S, renal function remained unchanged and no adjustement in Cs dosage was necessary. These data are in agreement with the results obtained in the in vitro model. On the one hand, this model using hepatic microsomal fractions confirms the participation of an enzymatic inhibition in the developement of these interactions, on the other hand it could be considered to have a good predictive value in clinical practice. Pharmacologic Clinique, H6pital Broussais, 96 rue Didot F75674 PARIS Cedex 14.

TOBRAMYCIN VOLUME OF DISTRIBUTION CHANGESDURING COMBINATION ANTIBIOTIC THERAPIES

PP 11.41

PP 11.43

~ I V E

]I~IIBITI~ OF DRUG ~TABOT.IS~ BY C Y ~ R I N

M.Murata*, Y.Nakahara*, Y.Yoshioka*, K.Tanaka, T.Suzuki, F.Otsu, Y.Hariya, K.Nagasawa, K.Yahata Dept. of Pharmacy Services* and Internal Medicine, Nippon Medical School, Tama-Nagayama Hosp. Tokyo, Japan In order to c l a r i f y a changing of tobramycin (TOB) pharmacokinetics during a combination therapy with another a n t i b i o t i c s , I00 patients with infectious disease receiving TOB alone (TA group, N=32) or TOB + another a n t i b i o t i c s (TC group, N=68) were studied. TOB was given i n i t i a l l y with a loading dose (l-2mg/kg) and a d a i l y maintenance dose using Hull-Sarubbi's method. Another a n t i b i o t i c s were prepared by another b o t t l e and given apart from TOB. TOB serum levels were measured BY FPIA method, and TOB serum-time data were analyzed using a one-compartment m o d e l . , Each measured serum TOB level (ML) was compared to predicted serum TOB level (PL).Linear correlations between ML and PL in TA group and in TC group were 0.73 and 0.48 respectively. Linear correlation between measured TOB elimination rate and predicted TOB e l i m i nation rate were 0.93 in TA group and 0.78 in TC group. Mean TOB Vd were compared in TA and TC group. The mean TOB Vd were 0.29 +0.07 L/Kg in TA group and 0.39 + 0.14 L/Kg in TC group.'There was a s i g n i f i c a n t difference in Vd between two groups. The results obtained in this study that TOB serum levels in TC group do not related to predicted ones suggested that TOB levels may be varied more widely and/ or Vd may be changed to be large in combination with other a n t i b i o t i c s , We concluded that TOB serum levels in case of combination therapy should be kept below usual levels in as monotherapy.

A.

THE INFLU}~NCE OF ISONIAZlDPRE-TREATM~ONTHE ELIMINATION OF DEXAMETHASONE

E.J.D. LEE and S.M. Cyclosp0rin A (CsA), an orally active immun0suppressive agent has been reported to inhibit cytoc/irome p-450 (C-P450) dependant biotransforn~tion of drugs in r~ice and humans (i,2). However, this inh/blticn of oxidative metabolism of drugs by CsA appears to be selective for certain xenobiotics. In this study we examined selective inhibition of C-P450 mediated drug ~etabollsm by CsA; by using some homologous phanoxazone ethers (ethoxy-, pentoxy- and banzyloxyresorufin) as probe substrates for the differant forms of C-P450. Microsomes of livers of rats pretreated with saline, iAhenobarbital (PB) and 8-naphthoflavone (BNF); and 9 htuaan livers and placenta each from a non-smoklng and a s~oking mother ~ r e used. In saline pretreated rats, CsA maximally inhibited ~RDD, BROD and PROD activities to 88%, 80% and 58% of control respectively. In BNF pretreated rats, CsA mBximally inhibited EROD, PROD and pROD activities to 85%, 79% and 70% of control respectively. CsA had no significant effect on the metabolism of these phenozaxone ethers in microscmes of PB pretreated rats. CsA also inhibited ~%0D, BROD and PROD activities to 80%, 53% and 51% of control respectively in microsomes derived from the livers of non-smoking hm~3ns, In placentas .taken from a smoking and non-~roking mothers, CsA maximally inhibited ~RCD activities to 65% and 80% of control respectively; whereas PROD actlvitly was inhibited to 18% and 60% respectively. This study suggest that CsA selectively inhibits oxidative metabolism of xenobiotics in rat and human liver microsomes. In addition, smoking induces an isozymic form of BROD which is inhibitable by CsA. CsA is thus likely to give rise to specific interact/ons involving drugs which are metabolised by B~OD isozymlc forms, especially in smoking individuals. References 1. Moochhala S M, Renton, K W. Bioch~n. Pharmacol., 39, 1499-1503 (1986). 2. Maurer G, 9t al. Drug Metab. Dispos., 12, 120-126 (1984), D e ~ t of Pharmaoology, Faculty of Medicine, National University of singapore, I0 Kent Ridge Crescent, Singapore 0511. Supported by National University Grants No. RP 870372 and 870317.

Santoso B, Suryawati S, M~stofa & Dwiprahasto I Department of Clinical Pharmacology, Faculty of Medicine, Gadjah Mada University, Yogyakarta, Indonesia. Isoniazid (INH) has been shown to impair the metabolic disposition of other drugs by inhibition of endoplasmic reticular drug metabolising enzymes leading to reduced clearance and elevated serum levels of the affected drugs

(1). The effect of INH pre-treatment on the elimination of dexamethasone was investigated in 10 healthy male volunteers. Dexamethasone kinetics were studied on two oeeasions, first during control and second after pre-treatment w i t h INH 400 mg daily for 7 days. Dexamethasone (5 mg, 10 tablets) was given orally and serum samples were taken serially at 0, 1.5, I, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 12 and 24 hours after dosing. Serum dexamethasone concentration was assayed in duplicate by high-pressure liquid chromatographic method, and the pharmacokinetic calculation was performed by a PCNonlin software computer program. The half-life of dexamethasone after INH (3.4 + SEM 0.4 hr) was significantly (paired t-test, P<0.0O5) prolonged compared to that obtained during control (2.4 + 0.4 hr). Similarly, the area under the serum drug concentration vs time curve (AUC 0 ) was significantly increased after INH (584.0 ~ 6].7 -vs 461.1 ~ 46.6 ng/ml.hr). The peak concentrations of dexamethasone, however, were similar at both occasions, i.e. 100.8 + 12.2 ng/ml after INH and 102.1 + 13.7 ng/ml during control. This study showed that INH pre-treatment impair the elimination of dexamethasone. Reference: Bacievicz, A & Self TH (1985). Med. J. 78(6):714-8

Isoniazid

does appear to

interactions.

S.

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PP 11.46

PP 11.44 DRUG INTERACTIONS WITH RIFAMPIN

Suryawati S, Santoso B, *Hadjar ~ I & *Sar~joko W Dept. Clinical Pharmacology & *Dept. Analytical Chemistry Gadjah Mada University, Yogyakarta, Indonesia. This study was designed to investigate the effects of isoniazid (INH), pyrazinamide (PYR) and rifampin (RIF) alone or in combination on the pharmacokinetics of RIF. Eight healthy volunteers were recruited. T h e y underwent pharmacokinetic studies of RIF on 7 occasions i.e. (I) during control, (If) after INH 400 mg daily - I week, (III) INH 400 mg + RIF 450 mg daily - 2 weeks, ( I V ) PYR 1000 mg daily - 2 weeks, (V) PYR 1000 mg + RIF 450 mg daily- 2 weeks, (VI) INH 400 mg + PYR 1000 mg + RIF 450 mg daily- 2 weeks, and (VII) RIF 450 mg daily-1 week. Each study was separated from the other by an interval of I month. RZF pharmacokinetic studies were done after oral 450 mg dose and serial serum samples were taken for 24 hours after dosing. Serum RIF concentrations were assayed by HPLC method. The pharmacokinetic parameters were calculated by standard method and the mean values were as follow: .......................................................... Parameters I II III IV V VI VII .......................................................... Cmax (ug/ml) 16.0 15.4 13.2 14.7 17.3 13.5 21.1 TI/2 (hours) 4.6 *6.3 "3.1 5.3 *3.4 *3.4 "3.1 AUC 0 ~ 123.8 135.4 *70.6 123.4 100.5 *90.5 *93.3 (ug/ml.hr) .................................... - ..................... *Analysis of variance, P<0.05 compared to I This study shows that INH given alone impairs the elimination of RIF, but combination with RIF reverses this inhibition. PYR, however, does not appear to affect the pharmacokinetics of RIF. RIF given alone or in combination with INH, PYR or both, clearly accelerates its own elimination as reflected by shorter half-life and reduced area under the curve.

VENTILATORY EFFECTS OF THE COMBINED ADMINISTRATION OF KETOROLAC AND MORPHINE IN HEALTHY SUBJECTS L.J.C. Brandon Bravo, J.G. Bovill, A.G.L. Burm and Joh. Spierdijk

Introduction Ketorolac tromethamine

(KT) is a potent non-opioid analgesic suitable for parenteral administration. Several studies have demonstrated K T ' s efficacy in alleviating postoperative pain. When given in combination with morphine, morphine requirements were reduced by about one third (G.W.A. Gillies, et a l . , Anaesthesia 42, 727, 1987). I t was also found that, in contrast to morphine alone, the combination did not cause any increase in PaCO 2. This suggests that KT might antagonise morphine-induced respiratory depression. The present study was designed to investigate this possibility.

Study design

In three sessions, seperated at least by a week, 9 healthy volunteers received either 5 mg morphine iv combined with a placebo im, 10 mg morphine iv combined with a placebo im or 10 mg morphine iv combined with 10 mg KT im. The study was conducted in a randomized, doubleblind crossover way. The ventilatory response to C02 before and after drug administration was assessed by the rebreathing method accordingto Read.

Results All three drug combinations caused a significant shift to the right of the COz-response curve. This shift was significantly greater in the subjects receiving morphine i0 mg compared to those receiving morphine 5 mg. The response curve in subjects receiving morphine plus KT was not significantly different from morphine plus placebo.

Conclusion These results demonstrate that KT i0 mg im does not influence the effect of morphine on C02-response. KT is therefore not an antagonist for morphine-induced respiratory depression. University Hospital Leiden, Department of Anaesthesiology, P.O. Box 9600, 2300 RC Leiden, The Netherlands.

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PP 11.47

PHARMACODYNAMIC INTERACTION OF BROMAZEPAM AND LORAZEPAM WITH METOPROLOL A.K. Scott, G. A. Cameron and G.M. Hawksworth

VINPOCETINE THERAPY DOES NOT INTERFERE WITH IMIPRAMINE PLASMA LEVELS G. H i t z e n b e r q e r , W. B r a u n * a n d R. G r a n d t * The influence of vinpocetine on imipramine steady state plasma levels was investigated in 18 h e a l t h y v o l u n t e e r s . 25 m g I m i p r a m i n e was given t.i.d, for a total of 21 d a y s , vinpocetine treatment was started

The effect of bramazepam (B) and lorazepam (L) on the blood pressure response to metoprolol (M) has been evaluated as part of a study of the pharmacokinetic and pharmacodynamic interaction between these drugs. Twelve healthy, non-smoking, drug-free male volunteers (age 21-37 years) gave written informed consent for the study. Each received single doses of B (6rag) and L (2rag) alone and after 3 days pre-treatment with M (100mg twice daily) in random order. Each of the study days was separated by at least 2 weeks. Pulse and blood pressure (BP) were measured before dosing and for 12h pest-dosing using a Copal semi-automated sphygsmomanometer. Measurements were made during the third day of treatment and again on the fourth day of treatment when B or L was administered with M. L had no overall effect on either pulse or systolic or diastolic blood pressure in the presence of M. B had no effect on pulse or diastolic pressure but did tend to lower systolic pressure. Pre dose BP (mean) m s 112/64 mmHg while at 6h post dose BP was 113/61 for M alone and 104/65 for M + B. The means of the differences and 95% confidence intervals (CI) for systolic blood pressure on M alone and M + B are shown below: Time (h) 0 Mean -0.9 (mmHg) Cl -10.2 to 8.3

1 7.1

2 6.3

0.2 to -0.5 to 13.9 13.0

4 6.0

6 9.1

12 7.2

I.i to 10.9

2.1 tO 16.1

i.I to 13.2

The small changes in systolic blood pressure with B in the presence of M are unlikely to be clinically important. Clinical Pharmacology Unit, Aberdeen, AB9 2ZD, Scotland.

University

of

Aberdeen,

o n d a y Ii w i t h i0 m g t . i . d , a n d c o n t i n u e d u n t i l the e n d of t h e s t u d y . T h e A U C s of i m i p r a m i n e plasma levels were obtained using consecutive imipramine plasma level determinations from s a m p l e d r a w n e v e r y t w o h o u r s f r o m 8 a.m. to 8 p.m. by trapezoidal rule. AUCs of day 10 without and of day 21 during concomitant vinpocetine treatment were compared, demonstrating independence of imipramine's bioavailability from concomitant vinpocetine treatment. There were no hints suggesting a changed resorption of i m i p r a m i n e d u e to v i n p o c e t i n e as w o u l d be r e f l e c t e d in C| a n d tmax v a l u e s . Imipramine metabolisation to the still effective metabolite desipramine shows a huge interindividual variability while it is a constant regarding the individual. The analysis of t h i s p a r a m e t e r in t h e c o u r s e of t h i s s t u d y does not suggest that it is changed due to vinpocetine treatment. Klin. Pharmakologie, I. M e d . U n i v . - K l i n i k , A-1090 Wien *Thiemann Arzneimittel G m b H , Im W i r r i g e n 25, 4355 Waltrop

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PP 11.48

PP 11.50

PBARMA~C AND PHARMACODYNAMIC INI~CTION$ OF CAP~AMAZE:INE WITH HALOP~IDOL IN SCHIZOPHRenIC PATIenTS. Theisohn,M.*, Dose,M.**, Apelt,S.**, Emrich H.M.** * Department of Phan~acolngy, University of Cologne, and ** Max PlanckInstitute of Psychiatry, Munich, FRG Carbamazepine (CBZ) has a psychotropic effect and is usefull in psychoaffective psychosis. In schizophrenic patients with EEG abnormalities the combination of a neuroleptic with CBZ was of advantage. There are a few studies denosstrating that the addition of CBZ decrease the serum levels of haloperidol (B). In some the therapeutic effect was increased and in others decreased. The aim of the present randomised, double blind and placebo controlled study with schizophrenic patients was to demonstrate the clinical antipsychotic effectiveness of the combination of H and CBZ in correlation to their measured serum levels. 22 patients with a schizophrenic or schizosffective psychosis were enclosed after giving informed consent. Therapy was started with 6 mg/d B increasing this dosage by 3 m~/d every 5th day if necessary. Chlorprothixen and biperiden were allowed as comedication. CBZ (or placebo, 6 tabl./d) was started with 200 mg increasing by 100 mg daily till tromgh levels of 8-12 mg/l were assessed. The psychiatric status end the side effects were recorded by rating scales (IMPS,BPRS,CGIS,~S) before, after 4 weeks and 1 week after the discontinuation of CBZ. Drug serum levels were estimated weekly: CBZ and its metabolites by a HPLC method, H by a GC method with capillary fused-silica column and a NP-detector. Both groups improved during 4-5 weeks by 50-60 ~ in their psychotic symptomatic. H reqnir~ent in the placebo group was 11.3 mg/d and was reduced in the CBZ group (8.3 m~/d).The need of biperiden was smaller (i.i to 3.9 rag/d) in CBZ as well as those for chlorprothixen (41 to 112 rag/d). Additionally frequency and severity of side effects was s ~ l e r in the CBZ group.In the placebo group H concentrations increased from 2.4 to 6.5 ng/l during 4 weeks whereas in the CBZ group the concentration was stable at 1.6 ng/l. This is a 75 % reduction in the H concentration compared to an 0nly 25 % reduction in the dosage. The reduction in the needed H dose may be a consequence of a p ~ c o d y namic interaction in the CNS whereas the reduction of the serum levels beyond the reduction of the dose may be a consequence of H displaoment from the alphal acid glycoprotein by CBZ. This last probability is under further investigation.

PHARIvl,qCOKINETICS OF VALPROIC ACID GIVEN CONCOMITANTLY WITH PHENOBARBITON IN ADULT EPILEPTIC PATIENT5

N.Pokrajac,B.Miljkovi~,V. Varagi~ and Z.Levid Pharmacokinetlc i n t e r a c t i o n which exists between valproic acid (VPA) and phenobarbitone (PB) was investigated following plasma levels and pharmaeekineties of VPA i n adult e p i l e p t i c patients. Both control (n=lO) and the

group of patients on PB therapy (n=lO) were given single oral doses of 900 mg of sodium valproate, and plasma levels and pharmacokinetics of VPA were followed during 12 h, as weel as at steady state a f t e r administration of 5 x 5OO mg o f the drug~day.All the patients were on standardized e l i n l c a l protocol, and took the food 2 h a f t e r the drug was glven. VPA in plasma was determined by gas chromatographic method a f t e r chloroform extraction. I t was found that PB had influence an VPA plasma levels, and probably due to induction of l t s metabolism, lowered VPA levels for about 40%. In comparison wlth VPA monotherapy, elimination pharmacoklneties of VPA in the presence of PB was also changed. That was documented by the s i g n i f i c a n t difference in important elimination parameters o f VPA: elimination rate constant (ke l), 0.073 + + 0.019 vs. 0.047 - 0.012 1/h (mean - SD) and t o t a l c l e arance (C1), 0.015 ~ 0.034 vs. 0.009 ~ 0.005 1/h/kg had higher values, while elimination h a l f 11fe ( t . , ~ ) , 9.9 ~ 2.1 vs. 15.4 ~ 5.5 h hod lower value d u ~ g concomitant administration o f the drugs. The re su lt s atso indicated that administration of VPA doses usual in monatherapy did not provlde therapeutic levels o f VPA during concomitant administration with PB, and consequen t l y not the eorrespoding e f f e c t (Cssmin 50.6 ~ 5.5 vs. 49.8 ~ 12.0, and Cssmax 50.4 ~ 6.8 vs. 71.1 ~ 15.6 mg/1 in monetherapy). Department o f Pharmacology and Pharmaeekinetics, Faculty of Pharmacy,P.P.Bex 146, 11000 Belgrade, Yugoslavia

PP 11.49

PP 11.51

ALCOHOL CONSUMPTION ALTERS THE PHARMACODYNAMICS OF ALFENTANIL H. J. M. Lemmens, J. G. B o v i l l , P. J. Hennis, M. P. R. R. Gladines and A. G. L. Burm Two groups of women, ASA I, undergoing curative surgery f o r rimary breast cancer were studied. Patients in group D n=6) had an average d a i l y consumption of the equivalent of 2-4 units (20-40 g) of alcohol. Patients in group A (o=8) were l i f e - l o n g abstainers or drank only occasionally (<6 units per year). Anaesthesia was induced and maintained with 66% N20 in 02 and a l f e n t a n i l . A l f e n t a n i l was administered by a computer controlled infusion pump. I f , during surgery, the p a t i e n t exhibited signs of inadequate anaesthesia (response), the target a l f e n t a n i l plasma concentration was increased by 50-100 ng/ml. I f there was no response during a 15 min period, the t a r g e t concentration was lowered by 50-100 ng/ml. A r t e r i a l blood samples were taken before any change of the target concentration, 4 min a f t e r a new target concentration was achieved and at extubation. Plasma concentrations were determined by c a p i l l a r y gas chromatography. A l f e n t a n i l protein binding was measured by e q u i l i b r i u m d i a l y s i s . Plasma a l f e n t a n i l concentration-effect data were analyzed by l o g i s t i c regression, where e f f e c t was e i t h e r response or no response t o surgical s t i m u l i . The average t o t a l a l f e n t a n i l requirement was s i g n i f i c a n t l y (p < 0.005) higher in group D (3.7 • 1.2 ~g kg"t min 4) than in group A (1.9 • 0.4 ~g kg I min4). The average CA50 (the plasma concentration for which the p r o b a b i l i t y of no response during surgery is 50%) was s i g n i f i c a n t l y (p < 0.001) higher in group 0 (522 • 104 ng/ml) than in group A (208 • 26 ng/ml). The average plasma concentration at extubation, in the patients who did not need naloxone, was s i g n i f i c a n t l y (p < 0.001) higher in group D (372 9 114 ng/ml) than in group A (176 • 39 ng/ml). There was no difference in the plasma protein binding of a l f e n t a n i l between the groups. These results indicate that regular alcohol consumption leads to pharmacodynamic tolerance to a l f e n t a n i l . University Hospital Leiden, Department of Anaesthesiology, P.O. Box 9600, 2300 RC Leiden, The Netherlands

EFFECT OF PHENOBARBITAL AND PHENYTOIN ON PHARMACOKINETIC PARAMETERS O F T HE A N T I C O N V U L S A N T R A L I T O L I N E A. von Hodenberg, I. Fecht-Kempter, K.-O. Vollmer, *I. Schleyer, *H.N. Bockbrader and *A.J. Sedman Ralitoline, a thiazolidinone, shows antieonvulsant activity in different animaI models. In volunteers, ralitoline is well tolerated and shows linear pharmacokinetics. Because ralitoline is extensively metabolized, interaction studies with phenobarbital (PB) and phenytoin (DPB), drugs likely to be coadministered with ralitoline and known to affect drug metabolism, were performed. In two separate studies, male subjects received a single 100 mg oral dose of ralitoline alone and after a 14 days pretreatment with PB (i00 mg/day) or DPH (300 mg/day). Subjects also received a multiple dose regimen of ralitoline (i00 mg every 8 h) for at least ]I days with concomitant PB or DPH administration. Blood samples were taken for assay of ralitoline plasma concentrations following each single dose administration of ralitoline. During PB or DPH administration, several blood samples were collected for analysis of PB or DPR trough plasma concentrations. Ralitol{ne, PB, and DPI[ Dlasma samples were analyzed using validated HPLC methods. Single-dose ralitoline bioavailability decreased about 2-fold after PB or DPH administration relative to that of ralitolJne administered alone. Tmax remained unchanged at 2 hours. Ralitoline elimination half-life decreased from 4 to 3.5 and from 4 to 3 hours following eoadministration of PB and DP}{, respectively. Thus, relative bioavailability of ralitoI~ne was redu6ed by concomitant administration of PB of DPH presumably due to hepatic enzyme induction. Steady-state plasma concentrations of PB or DPH were unaffected by concomitant administration of multiple doses of ralitoline. Gbdecke Research Institute, Department of PharmacokinetJes and Metabolism, Mooswaldallee ]-9, D 7800 Freiburg *Parka-Davis Pharmaceutical Research Division, WarnerLambert Co, Ann Arbor, MI 48~05, USA

I

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PP 11.52 GLIBENCLAMID CONCOMITANT II D I A B E T I C

STEADY

STATE

VINPOCETINE PATIENTS

PLASMA

LEVELS

ADMINISTRATION

DURING IN

TYPE

R. Grandt, H.-U. Schulz*, F. Gehl*, B. Lfihr~ann* The influence of v i n p o c e t i n e on glibenclamid s t e a d y s t a t e p l a s m a l e v e l s was i n v e s t i g a t e d in 18 p a t i e n t s s u f f e r i n g f r o m t y p e II d i a b e t e s a n d s y m p t o m s of d e m e n t i a . D u r i n g the s t u d y p a t i e n t s continued to f o l l o w their individual s c h e m e of g l i b e n c l a m i d intake and i0 m g v i n p o c e t i n e were given t.i.d, from d a y 2 to 5. Glibenclamid as w e l l as g l u c o s e plasma levels w e r e r e p e a t e d l y d e t e r m i n e d on the first d a y of the trial and c o m p a r e d to t h o s e on the f i f t h day where patients had received additional v i n p o c e t i n e m e d i c a t i o n for four days. T i m e p o i n t c o m p a r i s o n s w e r e e m p l o y e d to e x c l u d e clinically relevant changes of glibenclamid bioavailability and kinetics. The data of t h i s t r i a l s h o w that v i n p o c e t i n e does not interfere with the kinetics of glibenclamid. Thus, it c a n be c o n c l u d e d , the comedication with vinpocetine does not represent a potential risk for a drug interaction in c a s e of a n t i d i a b e t i c treatment with glibenclamid. *Medical University L~beck, Dept. of A n g i o l o g y and Geriatrics, Section of Clinical Pharmacology, Ratzeburger Allee 160, D-2400 L~beck I Thiemann Arzneimittel GmbH, Im W i r r i g e n 25, D-4355 Waltrop

E F F E C T OF H E M E ON B I N D I N G OF D R U G S TO H U M A N SERUM PROTEINS M. K a n ~ a s a h o , A. J u h a k o s k i , T. K l e i m o l a I n t r a v e n o u s h e m a t i n i n f u s i o n s h a s b e e n u s e d for t r e a t m e n t of a c u t e p o r p h y r i c a t t a c k s since 1970s. R e c e n t l y a s t a b l e and safe h e m e i n f u s i o n c o n c e n t r a t e ( N o r m o s a n g ~, Leiras, F i n l a n d ) has b e e n d e v e l o p e d a n d s h o w n to be d e v o i d of m a n y a d v e r s e e f f e c t s of the c o n v e n t i o n a l h e m a t i n t h e r a p y . We h a v e s t u d i e d the a b i l i t y of h e m e to d i s p l a c e v a r i o u s d r u g s f r o m t h e i r b i n d i n g sites in h u m a n s e r u m in o ~ d e r to c l a r i f y f u r t h e r the s a f e t y of N o r m o s a n g treatment. H e m e is i n i t i a l l y b o u n d to a l b u m i n (K~ 10-8M) a f t e r a d d i t i o n to h u m a n s e r u m and w i t h i n several hours transferred ~ a specific binding protein, h e m o p e x i n (K d i0M) (Morgan WT et. al., Biochim. B i o p h y s . Acta, 444, 435, 1976). A f f i n i t i e s of d r u g s t~ h u m a n s e r u m a l b u m i n are u s u a l l y l o w e r (Ka I0- M) and thus t h e y are p r o b a b l y d i s p l a c e d by h e m e if b o u n d to same site of a l b u m i n . N o r m a l h u m a n s e r u m w a s i n c u b a t e d w i t h some d r u g s k n o w n to be t y p i c a l for v a r i o u s b i n d i n g sites on a l b u m i n or u s e d in the t r e a t m e n t of p o r p h y r i c attack. H e m e w a s a d d e d later and its a b i l i t y to d i s p l a c e the d r u g s m e a s u r e d b y an ultrafiltration method. Leiras, B i o m e d i c a l R e s e a r c h Center, P . O . B o x 415, S F - 2 0 1 0 1 T u r k u , Finland

PP 11.53

PP 11.55

DEXTR4/~-LIGNOCAINE INTERACTION DURING EPIDURAL ANAESTHESIA A.M. Alkhawajah, A., Absood, H., Faraz, M., Nasuib.

INTERACTION OF TRICYCLIC ANTIDEPRESSANTS AND NEUROLEPTIC DRUGS WITH MORPHINE-UDP-GLUCURONYL TRANSFERASE IN HUMAN LIVER B. Ask, A. Wshlstr~m and A. Rane Neuroleptics and antidepressants are often used concomitantly with morphine in cancer patients with severe chronic pain. Morphine is primarily metabolised by the microsomal UDP-glueuronyl transferase (GT). This enzyme also catalyses the conjugation of the other drugs. The present results describe the metabolic interaction between these drugs in human liver microsomes. Methods: The glueuronJdation was performed according to Paeifici et al. (1982), and the glucuronides formed were analyzed by high performance liquid chromatography. Results: Morphine UDP-GT was inhibited by all tested drugs. Competitive inhibition of morphine glucuronidstion was observed for naloxone, oxazepam, diazepam, eyproheptadine and fenoterol. The other tested drugs included haloperidol, amitriptylin and nortriptylin. Activation by Lubrol (0.25 mg/mg protein) was found to enhance the formation of 5'-morphine glucuronide (4-fold) and of 6'-morphine glucuronide (5-fold). The same degree of activation was observed in the presence of the inhibiting drugs. Inhibition was also confirmed when the drugs were tested in vitro at the concentration r a t i o ( t r i c y c l i c s / m o r p h i n e ) t h a t i s achieved in plasma o f p a t i e n t s t r e a t e d w i t h these drugs. The in viva interaction and the dinieal significance of these results remains to be studied.

Although some investigators have shown that addition of dextran to local anesthetics prolongs the anesthetic effect, there are reports which do not support this finding. Thus we studied the effect of the addition of dextran 70 to lignocaine during epldural anesthesia in ten adult male herniorrhaphy patients. These were allocated randomly into two groups. Lignoeaine (5mg/kg) was administered epldurally in 30ml dextran 70 in saline solutin to group I (n=5) and in 30ml saline solution to group II (n=5). The duration of analgesia was calculated as the time from injection of lignocaine until the patients noted postoperatively that numbness in the groin has woz~n off and pain occurred. Lignocaine concentrations in blood were determined at different time intervals. It was found that the duration of analgesia ranked from 70-90 min in the lignoeaine dextran group and from 60-75 min in the lignocaine saline group. The Cmax (2.6 ug/ml) in group II was higher than that (2.0 ug/ml) in ~roup I. The time for maximum plasma concentration (~max) and AUC were found to be 30 min and I0 respectively in group II while that for group I were 45 min and 18. These differences were statistically significant. When the dynamic dialysis of lignocaine and dextran was studied, the elimination of lignocaine from the dialysis bag was retarded by the presence of dexran 70. The percentage binding of llgnocaine was 72%. The findings of this study indicate that dextran 70 significantly delayed the pharmacokinetlcs profiles o f epidurel lignocaine and this is probably due to the binding of llgnoealne to dextran molecules. Departments of Pharmacology,and Anesthesiology, College of Medicine, Da~mam, Saudi Arabia.

Division of Clinica] Pharmacology, University Hospital, 5-751 85 Uppsala, Sweden.

A 272

PP 11.56

PP 11.58

QOINfKXINEANTIBIOTICS INHIBIT P450-DEPI~NTD~NT DRUG ~ISMINHUMANLIVERMICROSOMES. U. Fuhr*f T. Wolff** r S. Harder*~ A. H. Staib* Effects of ofloxacin (OFL), pipemidic acid (PPA), and ciprofloxacin (CIP) on caffeine degradation were examined in vitro using human liver micros~,~e suspensions from two donors. Four primary n~tabolites of caffeine were found: 1,3-di~ethylxanthine (I ,3-D~), I, 7-dinethylxanthine (I, 7-D>~), 3,7-dimethylxanthine (3,7-DMX), and 1,3,7-trimethyluric acid (I ,3,7-T~J). She formation rate of 1,3-DMX, and 1,7-~4X without inhibitor followed simple Michaelis ~ n t e n kinetics at concentrations of caffeine up to 2 ~M, whereas 1,3,7-~ kinetics indicated the presence of two binding sites. OFL, PPA, and CIP had a low inhibitory effect on 1,3,7-q~U formation but marked inhibitory action in the case of 1,3-~[X, and 1,7-~,IX. Dixon plots shc~Jed that the inhibition of 1,7-DMX formation (the main metabolite) was always competitive.

PREVENTION OF GENTAMYCIN NEUROMUSCULARBLOCKADE IN RAT ISOLATED DIAPHRAGM BY LITHIUM T. Samadian, A. R. Dehpeur and F. Roushanzamir The importance of a n t i b i o t i c - i n d u c e d neuromuscular paralysis has been documented in animal experiments and c l i n i c a l s i t u a t i o n s . We have studied the e f f e c t o f p a r t i a l replacement o f NaCl content of the media by LiCl on i n h i b i t o r y action o f gentamycin in r a t i s o l a t e d phrenic-nerve diaphragm preparation. The diaphragm was kept in Krebs s o l u t i o n and was supramaximally stimulated via the phrenic nerve at a rate of 0 . I Hz and 0.2 ms duration. Gentamycin was added to the media and i t s i n h i b i t o r y action on t h e t w i t c h contractions was recorded. The IC50 (concentration r e s u l t i n g in 50 percent depression o f the o r i g i n a l twitch tension) o f the gentamycin was found to be 2.33 mM. Thereafter NaCI was p a r t i a l l y replaced by LiCl and the e f f e c t of gentamycin was studied in t h i s

Apparent affinity constants Km, KII(mM) and formation rate of 1,7-DMX (pmol 1,7-DMX-min- .mgprotein-1) Vmax Caffeine(~n) OFL(K I) PPA(K I) CIP(K I) Donorl 104 0.58 1.52 0.25 0.09 Donor2 241 0.61 >1.0 0.29 0.09 The affinities of OFL, PPA, and CIP to the binding site reflect the inhibitory effects in vivo determined in volunteers. In preliminary studies we observed that quinolone antibiotics also decreased the 7-hydroxylation of Co~Terin. These investigations suggest that inhibition of P450 dependent metabolism by quinolone antibiotics is a c a ~ o n phen~nenon. * Abt.Klin.P.har.nakologie, Universit~tsklinik Fr~%kfurt Theodor-Stern-l
media. Incubation of the preparation in 0.5, 1.5 and 5:0 mMLf+30 mffiut4s prior to the application of gentamycin prevented the inhibitory effect of the antibiotic by a value of 7.7, 19.6 and 29.0 percent respectively. The doses of Li+used in this experiment were low and close to the therapeutic l evel o f the drug. I t is suggested t h a t the e f f e c t o f Li+~s p r i marily mediated by an action on a c e t y l c h o l i n e release at neuromuscular j u n c t i o n . Pharmaceutical Research Center. Daroupakhsh Co. Tehran-IRAN.

PP 11.57

PP 11.59

CYCLOSPORINE-DRUG INTERACTIONS : STUDIES WITH HUMAN LIVER MICROSOMES D.J. Back & J.F. Tjia The immunosuppressant cyclosporfn (CSA) undergoes extensive hepatic metabolism in man to mono - and dihydroxylated as well as N-demethylated products. The major primary oxidative metabolites are MI, MI7 and M21. Since the introduction of CSA a large number of clinically important interactions with other drugs has been reported. We have established an in vitro system using human liver microsomes and a sensitive hplc system for determination of the main CSAmetabolites to screen drugs which may have a propensity to inhibit CSA meSabolism. have particu/arly focussed our attention on CA2 channel antagonists and anti-fungal drugs. Histologically normal human livers were obtained from renal transplant donors. Microsomal incubations (for 30 min) contained 3H-CSA (40~M; 0.2~Ci), NADPH (imM), microsoma] protein (3 mg), MgCI 2 (5mM), EDTA (ImM), KCI (ImM) and 1/15 M phosphate buffer (pH 7.4) to a final volume of 2.5 ml. In some incubations, diltiazem, verapamil, nifedipine, nicardepine (5-5OPM) ketoconazole, clotrimazole, m/conazole, flacenazole, terbinafine (0.5-s were added. CSA and metabolites were quantified by hplc on a Partisil ODS-3 column at 76 ~ with a mobile phase of aeetonitrile: water (67: 33; flow rate 125 ml min-l). Of the CA2 channel antagonists, nicardepine produced marked inhibition of CSA metabolism (IC50 = 8PM for both M17 and M21) whereas nifedipine produced less than 10% inhibition of M21 and MI7 at 50~M. The nifedipine data are interesting in relation to tho~ possibility that P450NF is involved in CSA metabolism, the antifungal drugs, ketoconazole was a potent inhibitor of both MI7 (ICs0 = 2.1pM) and M21 (ICs0 = 2.0~M) production. The alylamine, terbinafine was essentially non-inhibitory. Department of Pharmacology & Therapeutics, University of Liverpool, P.O. Box 147, Liverpool L69 3BX, U.K.

EFFECT OF HISTAMINE H2 ANTAGONISTS ON THE RENAL TUBULAR SECRETION OF TRIAMTERENE AND ITS SULPHATE CONJUGATE METABOLITE IN THE ISOLATED PERFUSED RAT KIDNEY. A.A. Somogyi, M.R. Muirhead, F. Bochner. An i s o l a t e d perfused rat kidney model has been used to examine the renal handling o f the potassium sparing diuretic triamterens (I) and its active metabotite phydroxytriamterene sulphate conjugate (T-O-S04), and the effect of the histamine H2 antagonists cimetidine (C), ranitidine (R) and famotidine (F) on their renal clearance rates. Kidneys from male wistar rats were isolated and perfused with a Krebs-Henseleit buffer containing albumin, glucose and amino acids to pH 7.4 at a mean perfusion pressure of 110-10 mm Hg. perfusate samples were collected at the mid-point of 30 min urine collection periods. Drug concentrations were measured by HPLC. At an initial T concentration of 0.7 mg/L, the unbound renal clearance to glomerular filtration rate (GFR) ratio was 11.0• (mean• indicating tubular secretion of T. This ratio was significantly (p(O.05) reduced by C (1.5• R (Z.8• and F (5.3• indicating inhibition of tubular secretion. For T-O-SO&, the unbound renal clearance to GFR ratio was 41• indicating even greater secretion of this conjugate which was not inhibited by C (44e18:1), R (31• 13:1) or F (39-15:1), but was inhibited by probenecid (7-2:1). These data indicate that the secretion of [ and T-D-S04 is via the organic base and acid t~ansperting systems respectively, and that famotidine is a weak inhibitor of the organic base system in contrast to cimetidine and ranitidine which are more potent inhibitors. The data also illustrate how metabolism can significantly alter the physiological elimination of a xenobiotie whereby the parent compound and its metabolite can be cleared by different renal transporting systems. Department of Clinical and Experimental pharmacology, University of Adelaide, Ades 5001, Australia.

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PP 12.01

PP 11.60 CEPHALOSPORINS INCREASE THE Pd~UkL CLFJkR~CE OF b~l]{~%~ IN RABBITS H. Brasch and H. Iven Tubular secretion and reabsorption are involved in the renal elinlination of methotreyate (zvfI"X).We investigated, whether antibiotics which are actively trmasported in the kidley ~]emselves alter d~e renal clearance of the cytostatie. Anaesthetized rabbits received an infusion of }~fX (30 zg/kg x min) ar/d inulin (0.5 mg/kg x min) for 4 h. Saline solution (0.24 ml/kg x min) was given additionally. After 80 min, saline infusion was replaced by a test drug infusion and after a further 80 min the initial drug infusion rate was increased threefold. Infusion rates (IR; ~g/kg x re_in) and the observed changes of the total (Qi~yf) and renal (Q~I) clearance of bFfX and its metabolit@ ~" 7-hydmoxymethot~r~4xate (7-OH-I~PX) are given in the table (ml/kg x min;*P----~0.05; n = 7).

P;b~ G c~1Fq7_~s CEI~2A

CF/TI C23FO

1320

+0.24+0.62

+0.15+0.37

+1.24+0,66

3960

-2.11~0.45"

-1.49_~0.33"

-1.30+_--0.64

53

159

+2.05+0.42* +2.96~0.98"

+1.14+0.27+3.30~0.86"

+1.72+0.26" +3.36~0.99"

420 1260

+0.08+0.24* +1.17_~0.42"

+0.84+0.19" +1.61~0.39"

+3.12+1.24" +5.13___1.17"

460

+1.11+0.55

+0.66+0.38

+1.45+0.92

1380

+1.4910.58"

+0.82+_--0.24*

+2.59+_--0.77*

380

+1.71+0.58"

+0.87+0.34*

+3.21+1.28"

1140

+0.15+_--0.63

-0.02+_-0.37

+0.84+_--0.70

Predrug clearance values (ml/kg x min) were: 6.1 - 8.4 (total ~[fX); 2.7 - 4.3 (renal ~n~{) and 3.6 - 5.6 (Penal 7-OII-~,~fX). A competitive reduction of the tubular MTX secretion can explain the decrease of the MTX clearance observed with penicillin G (p~21 G). Ceftriaxone (CF2%!R), ceftazidime (.~TA), ceftizoxime (CEIFTI), and cefoperazone (CEFO) seem to reduce the reabsorption of ~2X and 7-OH-~[I~ in t/]e tubulus. Institut f{ir Pharmakologie der Y~dizinischen Universit~t zu LUbeck, Ratzeburger Allee 160, D-2400 L'dbeck, FRG

SIMPLE COLORIMETRIC ESTIMATION OF O R T H O TRI-CRESYL-PHOSPHATE(TCP)IN EDIBLE 0ILS. VASWANI M E E R A , M A H A J A N BHIDE N.K.

P.M.,SETIA R.G. &

ALL INDIA INSTITUTE OF M E D I C A L SCIENCES, N E W DELHI-If0029 (INDIA)

A simple, rapid,sensitlve specific method for routine estimation of tri-cresyl-phasphate (TCP) is reported. TCP is extracted from 2ml of oil samples in 10ml rectified spirit or ethanol(95 to 99%) by brief shaking and 4 hr. standing at the room temperature. The rectified spirit layer is taken out and hydrolysed with NaOH at 35 C for 4 hr. It then gives blue color with 2:6 dichlorohenzoquinone-chlorimide. The method can detect upto 0.05% v/v of T C P in 2ml oil samples. For detecting lower concentrations(upio 0.0I%), 10ml oil samples need to be extracted with 25m1 rectified spirit. Further, by using this method, it was ascertained that T C P in the alcoholic phase can he readily removed by adsorption on the activated charcoal. CONCLUSION This method is suited for routine testing of large number of oil samples in industrial and public health laboratories. It may also prove useful for in all types of processed foods,

detecting

TCP

T h e f i n d i n g t h e TCP in a l c o h o l i c p h a s e g e t s readily, adsorbed by activated charcoal would b e u s e f u l in t r e a t i n g a c u t e o r a l p o i s o n i n g a n d in d e t o x i c a t i n g c o n t a m i n a t e e d o i l o r f o o d s t o c k s .

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ETHANOL MODIFIES THE ELECTROPHYSIOLOGIC EFFECTS OF CARDIO-ACTIVE DRUGS A. Gallardo-Carpentier, O.C. Carryl, R.L. Isaacson, R. S a l v a t i c i and R.G. Carpentier. The influence of acute and chronic exposure to ethanol (ETOH) on the acute in v i t r o effects of nicotine (NIC) and the calcium modulators Bay K 8644 (BAYK) and nimodipine (NIMO) was studied in rat s i n o a t r i a l preparations. Right a t r i a l s t r i p s beating spontaneously or driven at 5 Hz were superfused with Tyrode (37oc) while recording membrane potentials (MP). In preparations with spontaneous a c t i v i t y acute exposure to 240 mg % ETOH did not affect the sinus node rate (SNR) but i t slowed the onset of the depressant effect of NIC on SNR. It also antagonized the positive chronotropic action of BAYK and the negative action of NIMO. In a t r i a l fibers driven at a constant rate, ETOH and NIC exerted similar depressant effects on the amplitude of the action potential (AAP) and i t s overshoot (OS), w~th no changes in the resting membrane potential (RMP) and the Vmax of phase 0 (Vmax 0). These effects were not additive. The prolonging effect of NIC on the action potential duration (APD) prevailed over the shortening effect of ETOH. Severe chronic ETOH ingestion (35% of the caloric intake for 24 weeks) accentuated the depressant effect of NIC on OS and AAP. NIMO exerted on a t r i a l HP actions similar to those of ETOH. These effects were not a d d i t i v e . BAYK increased the OS and the AAP of a t r i a l f i b e r s , and it prolonged the APD. The MP remained unchanged when the preparations were exposed to ETOH and BAYK simultaneously, which indicates that the effects of these two drugs cancelled each other. Departments of Pharmacology and Physiology, College of Medicine, Howard University, Washington, DC 20059, USA.

F A C T O R S A F F E C T I N G T H E D E R M A L A B S O R P T I O N OF B E N Z Y L A C E T A T E IN T H E R A T S.A. Hotchkiss, S. Fraser, J.M. Miller a n d ~I, Caldwell Benzyl a c e t a t e (BA) is a w i d e l y used f r a g r a n c e a g e n t to w h i c h h u m a n s are exposed u p o n skin c o n t a c t w i t h perfumes, toiletries a n d household chemicals. T h e r e is c o n c e r n over its s a f e t y a f t e r such exposure, a n d studies are o n g o i n g to d e t e r m i n e its p e r e u t a n e o u s p e n e t r a t i o n a n d disposition. We h a v e developed an in vitro system w h i c h a c c u r a t e l y predicts in vivo a b s o r p t i o n (Hotchkiss, Br J P h a r m a c o l , 95, 580P, 1988), a n d have used this system to s t u d y the a b s o r p t i o n of BA t h r o u g h rat skin. Full thickness skin, f r o m the shaved dorsal region of Fischer 344 rats, was placed in cells in the in vitro skin d i f f u s i o n system. 14C-BA (1-/00ul in various vehicles) was a p p l i e d to the e p i d e r m a l s u r f a c e w h i c h was then o c c l u d e d with p a r a f i l m or left open to the atmosphere. The p e r f u s a t e (0.9% saline), w h i c h f l o w e d c o n t i n u o u s l y across the u n d e r s i d e of the skin (rate 1.5ml/h), was collected a n d assayed f o r p e n e t r a n t r a d i o a c t i v i t y . The a b s o r p t i o n of BA was m o d e r a t e l y r a p i d , c o m m e n c i n g w i t h i n lh a n d r e a c h i n g 49.3 + 2.0% (n=4) of the a p p l i e d dose at 48h. When appiied in 500/o (v/v) ethanol, the a m o u n t o f BA absorbed increased p r o p o r t i o n a t e l y with the c o n c e n t r a t i o n applied (r=0.997), over the r a n g e 1-100ul. Occlusion o f the skin enhanced BA absorption when applied in ethanol, p h e n y l e t h a n o l or d i m e t h y l s u l f o x i d e vehicles, a l t h o u g h it did n o t e n h a n c e t h e a b s o r p t i o n o f BA a p p l i e d a l o n e . The a p p l i c a t i o n of BA in ethanol, at vehicle contents >50% v / v , resulted in a n e n h a n c e d rate, b u t not extent, of BA absorption. P h e n y l e t h a n o l vehicle increased the extent (by up to 10%), but not the r a t e of BA absorption, w h e r e a s d i m e t h y l s u l f o x i d e (at contents >20%), e n h a n c e d both the rate a n d extent (by up to 15%) of a b s o r p t i o n of BA. These d a t a i n d i c a t e t h a t there are a n u m b e r of f a c t o r s w h i c h m a y a f f e c t the d e r m a l p e n e t r a t i o n o f a c o m p o u n d such as BA. Such f a c t o r s should be considered w h e n d e s i g n i n g e x p e r i m e n t s a n d i n t e r p r e t i n g d a t a d e r i v e d f r o m d e r m a l toxicology studies. D e p a r t m e n t of P h a r m a c o l o g y & Toxicology, St. Mary's Hospital Medical School, L o n d o n W2 IPG, U K . S u p p o r t e d by the R e s e a r c h Institute f o r F r a g r a n c e Materials.

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MAINTENANCE OF SOME CYTOCHROMEP450 ISOZYMES IN PRIMARY HEPATOCYTE CULTIIRE IN THE PRESENLE OF DIMETHYLSULPHOXIDE

EVALUATION OF CALCIUM CHANNEL BLOCKERS IN THE TREATMENT OF ACUTE CYANIDE TOXICITY G.E. Isom, J.L. Borowitz, B.K. Ardelt and J.D. Johnson Cyanide produces a rapid onset of convulsions, tremors and loss of consciousness which appear to be related to its central effects. If the acute toxicity does not produce death, it is not uncon~non that midbrain lesions are generated. Work in our laboratory demonstrated that exposure of mice to sublethal doses of KCN markedly elevated whole brain calcium. In vitro analysis in neuronal cell models (PC12 cells) indicated cyanide initiates a rapid, dose-dependent alteration Of cellular Ca homeostasis resulting in a six-fold increase of cytosolic f r e ~ Ca levels. Pretreatment of cells with diltiazem (I0 -~ M), a Ca channel blocker, prevented the rise in cytosolic Ca. Functionally, the elevated cytosolic Ca c a n initiate release of neurotransmitters producing activation of neuronal systems. In PC12 cells, I mM KCN induced the release of dopamine and norepinephrine which was blocked by diltiazem pretreatment. In brain slices, KCN induced a rapid release of glutamate which was partially blocked by Ca channel blockers. Since glutamate is known to be a central excitotoxic transmitter, it is likely this transmitter'mediates some of the central responses to cyanide. LD50 studies of KCN were conducted in mice pretreated with diltiazem (600 ug) alone or in combination with the cyanide antidotes, sodium nitrite and sodium thiosulfate. Diltiazem did not significantly change the LD50 of KCN either alone or in combination with the other antidotes. Diltiazem exhibits a low potential as an effective antidote against KCN-induced lethality. However, diltiazem blocked the tremors and convulsions associated with cyanide. It was concluded that diltiazem partially attenuates the sublethal actions of cyanide (convulsions and tremors) and appears to alter the activation of the glutamate excitotoxic neurotransmitter system. Dept. of Pharmacol. and Toxicol., Sch. of Pharmacy, Purdue Univ., West Lafayette, IN 47907 USA.

G.M. Hawksworth & C.K. Lindsay The major limitation of cultured mammalian hepatocytes for drug toxicity studies is the rapid loss of liver specific gene expression. In hepotocytes cultured on a thin layer of rat tail collagen (Type I), cytochrome P450 content fell to 13 +:2% of the fresh cell value over 7 days. When 2% (w/v~ dimethylsulphoxide (DM50), a solvent capable of inducing differentiation in a number of transformed cell lines~ was added to modified Earle's medium there was a significant improvement in eytochrome P450 maintenance. Addition of DMSO at Oh and 4h after placing resulted in values which were 46% and 61% respectively of the fresh cell values after a 7 day period. Associated mixed function oxidsse activities also show a rapid decline.in culture. Ethoxyresorufin-O-dealkylsse (EROD) is undeteetable after 5-7 days in conventional culture systems. When DMSO ~as added tc the culture system at Oh, EROD activity was 2 fold fresh cell values st 3d, declining to 60% initial activity at 7d. Addition of DMSO st 4h resulted in EROD activities which ~,ere 3 fold or equal to fresh cell values at 5 and 7 days respectively. The loss of pentoxyresorufin-O-dealkylase was not prevented by the presence of DMSO. These results may be due to a combination of de novo protein synthesis of selected isozymes and stabilisstion of existing enzymes. Despite improved maintenance of eytochrome P450, addition of 2% DMSO st either 0 or 4h resulted in o loss of protein content to 50% the values st time O. Lower DMSO concentrations may result in cytochnome P450 maintenance without the accompanying toxicity. Clinical Pharmacology Unit, Department of Medicine & Therapeutics and Department of Pharmacology, Polwsrth Building, Foresterhi11, Aberdeen AB9 2ZD.

PP 12.04

PP 12.06

THE FORMATION AND CARDIOVASCULAR ACTIONS OF CYCLOHEXYLAMINE IN DIABETIC PATIENTS GIVEN CYCLAMATE ORALLY A. G. Renwick, N. E. Buss~ and K. Donaldson Cyclamate (CHS) is widely used in many countries both as a food a d d i t i v e and in pharmaceutical preparations. Previous studies have shown that about 25% of the population can metabolise i t to cyclohexylamine (CHA), an i n d i r e c t sympathomimetic amine (see A. G. Renwick, Xenobiotica, 16, 1057-1071, 1986). These studies were conducted when cyclamate was a v a i l a b l e as a food a d d i t i v e and, t h e r e f o r e , the reported incidence and extent of metabolism may have been influenced by p r i o r and concurrent d i e t a r y intake. We are measuring the metabolism of CHS in UK di abet i c patients f o r whom no d i e t a r y sources are a v a i l a b l e in order to r e l a t e the extent of metaboism to the plasma concentration of CHA and to changes in heart rate and blood pressure. Urine and plasma samples and measurements of heart rate and blood pressure have been taken p r i o r to and a f t e r one week of administration of Ig CHS/day, given as the calcium s a l t . Urine samples were collected d a i l y and analysed f o r CHS, CHA and c r e a t i n i n e (to correct the data to 24h t o t a l s ) . Data f o r the f i r s t 100 patients to complete have shown good compliance with steady-state CHS excretion occurring by day 3 and averaging 27.2 • 13.6%. There was a very wide range of metabolism of CHS to CHA with <0.1% excreted by 74 p a t i e n t s , 0.1-i.0% by 14 p a t i e n t s , 1.0-10.0% by 9 patients and >10% by 3 p a t i e n t s . There was a s i g n i f i c a n t c o r r e l a t i o n between plasma CHA and the % metabolism of CHS (r=0.994; P
ACUTE ~-ADRENOCEPTOR ANTAGONIST TOXICITY - ITS RELATION TO MEMBRANE DEPRESSANT ACTIVITY AND ATTENUATION BY ASSISTED VENTILATION IN RATS. J.A.J.H. Critchley, Nipapan Pakayachuntavajana, Suleemas Komthong & A. Unsar. Many cases of ~-adrenoceptor antagonist (~-blocker) poisoning in man are uneventful and most reports of serious toxicity following acute overdosage concern ~-blockers with significant membrane depressant activity (MDA), particularly propranolol and oxprenolol. This is not surprising as ~-adrenergie tone is not essential for cardiovascular function in health. Our previous studies in rats comparing the acute toxicity of various B-blockers confirmed that prnpranolol was much more toxic than, say, nadolol with no MDA or sotalol. However we also found that assisted ventilation greatly attenuated the toxicity of all these 3 drugs. We have now compared the toxicity of propranolol with atenolol and bisoprolol using lung wet/dry weight ratios to determine whether the effect of positive pressure ventilation was to hinder the development of pulmonary oedema. Pentobarbitone anaesthetized rats (250 - 450 g) were infused (i.v.) at constant rate with the ~-bloeker solution while E.C.G. and arterial blood pressure were continuously monitored. The rats were either spontaneously breathing or artificially ventilated by a Starling Ideal pump. Arterial blood gases were monitored at intervals and the point of death assessed from the E.C.G. The mean (+ s.d., n = 7) doses (mg) at death for the ~-bloekers were:Ventilation PROPRANOLOL BISOPROLOL ATENOLOL Spontaneous(S) 22 + 3 79 + 12 240 + 23 Artificial(A) 45 T ll 268 T 51 1697 ~ 239 As the lung wet/dr~ weight r a t i ~ were lowe~ in the spontaneously breathing rats with both bisoprolol (S: 5.1 ~ 0.4, A: 5.8 ~ 0.7) and atenolol (S: 5.2 + 0.4, A: 5.9 + 0.9), pulmonary oedema did not appear ~elated to the p~oteetive action of artificial ventilation. Dept. of Clin. Pharmacol., Chinese Univesity of H.K. and Dept. of Pharmaeol., Edinburgh University~ Scotland.

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PP 12.09

ACUTE CARDIOTOXIC EFFECTS OF ORGANOPHOSPHATE PESTICIDE POISONING IN SUICIDAL PATIENTS M.Bala]i-Mood and F.Akhsvaln Ac--u-t-~o--r-g~-n-oph~-ophat~-pe--s~-c-idepoisoning (0 P) and its m echanism of action is well known, but its eardiotoxic effects has not been reported in detail. Of 221 OP cases admitted to our hospital in 1987, randomised 10 (4M,6F) severe intoxicated patients (aged 16-35 years)2-5h, after ingestion were investigated. Serum eholinestrase activity (Che)ereatine phosphokinase(CPK),lactic dehydrogenase(L D H) and further bioche micel and hae m atological tests were estimated. Specific treafiment (Atropine sulfate and obidoxime), cardiac monitoring and serial E C G before and during treatment were peformed. Serum Che markedly reduced to 0.25 Ku/L in all patients. C P K and L D H concentratiens elevated with a mean(_+SD) of 121+_95 and 850• U/L, respectively. Transient hyperglycemia, hypokalemia and leukocytosis ( W B C 11xlO-YL) were also observed during treatment. In 4 conscious patients, E C G revealed T wave and ST segment changes in shape and configuration and Q-T prolongation. These changes returned to normal after the specific treatment and the patients recovered. In the other patients who were comatous, hypotensive and artificially ventilated, ST depression with or without T wave inversion were observed. Despite specific and intensive therapies , these patients died I-4 days after ingestion. Postmortem examination of the heart revealed focal necrosis, m yocytolysis and general wavy fibres only in 2 of them indicating toxic myoearditis and ischemic changes of nyocardium.

CYTOGENETIC EFFECTS AND CELL I}~IUNITY IN HEROIN ADDICTS

Poisons Unit, E m a m Reza Hospital, Meshhad University of Medical Sciences, Mashhsd 91735, IRAN.

PP 12.08 CLASTOGENIC EFFECT OF STREET HEROIN IN NEWBORN INFANTS R.Rizzi, F.Re, E.Piatti, C.Vegni~ A.Marini*and E.Chiesara This study was carried out on 12 newborn infants, aged from 5 to 15 days divided into two groups: 6 (3 male and 3 female) from not addicted mothers (controls) and 6 ( 3 male and 3 female) from HIV negative addicted mothers. After obtaining chromosome preparations from lymphocytes of peripheral blood, following a routine protocol(Moorehead, P.S.,Exp Cell Res 20, 613, 1960), we examined i00 metaphases per subject selected with an IBAS II Zeiss Kontron image analyzer in order to evaluate chromosome aberrations. A quantitative evaluation of the micronuclei was carried Out on the same preparations, taking into account 2000 nuclei per subject. The test showed a significant difference in frequency of chromosome aberrations between controls and subjects from addicted mothers. The difference within each group between males ~nd females was insignificant. The mieronuelei frequency was also higher in offspring of drug addict mothers. These results show that ever in newborn infants, where the effect of environmental confounding factors is minimal, there is a clastogenic action due to heroin. Department of Pharmacology, Chair of Toxicology, Via Vanvitelli 32, 20129 Milano. ~Chair of Neonat~l pathology,Via della Commenda 12, 20122 Milano, School of Medicine~ University of Milan,Italy. This work was carried out within the project "medicina Preventiva e Riabilitativa" - SP5 "Rischio Tossicologico" of the National Research Council, grant no. 860172256.

INFECTED OR NOT BY VIH B. Sinugs~ M. Izquierdo,

P. Coloma, J. Pgrez, C. Larraz.

The majority group of risk in Spain among those individuals with the possibility of suffering AIDS is that o f heroin addicts by I.V. way. Civen that they are the lymphocites the infected cells by the virus and known its clastogenic effect, what has been pretended with this work has been to evaluate the eventual cytogenetic and immunity modifications induced by the heroin and VIH virus, For making this work is was taken a group of 96 pc! pie and this divided in another three groups. Group I ma de up by 30 individuals, smokers and in good health conditions. Group II, by 35 people, smokers and I.V. heroin addicts~ seronegativs to VIH, Epstein Barr, Citomegslov~ rus and B Hepatitis, Finally, group III made up by 31 in dividuals, smokers and drug-dependants and VIH seroposi ~ tivs. Among the cytogenetic parameters it was not modified micronucleus quantification (p>0,05) neither the frequency of sister chromatides exchanges (SCEs)(p>O,05), Group III showed an increase of the total of the chromosomic aberrations (p
PP 12.10 THE DILEMMA OF CLINICAL EVALUATIONS O F H E R B A L D R U G S IN A F R I C A N C O U N T R I E S

A.S. Elmi and A.M. Ahmed H e r b a l d r u g s h a v e an e x t e n s i v e use throughout the African Continent. In c o n t r a s t to s o m e o t h e r r e g i o n s of the W o r l d , in S u b - S a h a r a n Africa no recording of the p a s t u s e and the e x p e r i e n c e s of former generations with the traditionally used local medicinal p l a n t s is a v a i l a b l e . This makes more insecure and undetermined the u s e of t h e s e plants. In o u r e x p e r i e n c e , fresh extracts f r o m p l a n t s as u s e d by t r a d i t i o n a l practitioners a r e m o r e active than extracts f r o m d r i e d p l a n t s w h i c h res e a r c h and p h a r m a c e u t i c a l laboratories make use of. V a r i a b i l i t y is a l s o c a u s e d by the d i f f e r e n c e in s o i l a n d c l i m a t i c c o n d i t i o n s . Separations, isolation of a c t i v e c o m p o u n d s ete, h a v e s h o w n to p r e s e n t v a r i o u s inconveniences. The alternative s y s t e m w h i c h wel a r e a t t e m p t i n g , is to c a r r y o u t in the o r d e r t h e f o l l o w i n g stud i e s f o r e v e r y p l a n t w h i c h has a c o n s i s t e n t use in t r a d i t i o n a l medicine: i) T o x i c o l o g i c a l s t u d i e s in e x p e r i m e n t a l animals; ii) E x p e r i m e n t a l validtion of the e f f i c a c y p r e s u m e d by the t r a d i t i o n a l healers; iii) C a r e f u l o b s e r v a t i o n of h e a l e r s treating their patients; iv) C l i n i c a l evaluation of s t a n d a r d i z e d extracts. The paper will describe the r e a s o n s a n d the a d vantages of t h i s c h o i c e . Department of P h a r m a c o l o g y , Medical P . O . B o x 835 - M o g a d i s h u (Somalia)

Faculty

A 276

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PP 12.13

ASPECTS OF JAPANESE KANP0 (HERBAL) MEDICINE AS BEM. (II) NON-SPECIFIC IMMUNE RESPONSES IN TUMOR BEARING HOST.

ACCELERATING EFFECT OF A JAPANESE KAMPO M E D I C I N E O N R E C O V E R Y OF M U R I N E H E M A T O P O I E T I C STEM CELLS AFTER ADMINISTRATION OF MITOMYCIN C H. K a w a m u r a , H. M a r u y a m a , N. T a k e m o t o , S. S h i n o h a r a , Y. K o m a t s u , M. A b u r a d a a n d E. H o s o y a E f f e c t s of a J a p a n e s e k a m p o m e d i c i n e , Juzentaiho-to (TJ-48), on mitomycin C (MMC)-induced hematopoietic toxicity were investigated using colony-forming assays (CFU-S a n d C F U - G M ) in C 5 7 B L / 6 J m i c e . Intraperitoneal i n j e c t i o n of M M C r e s u l t e d in a m a r k e d suppression in t h e c o u n t s of C F U - S a n d C F U - G M . Oral administration of T J - 4 8 , w h i c h h a d b e e n started before MMC injection, did not protect m i c e f r o m t h e i n j u r y of h e m a t o p o i e s i s by MMC on day 1 post MMC injection but remarkably accelerated t h e r e c o v e r y of C F U - S a n d C F U - G M after that. T h e e f f e c t of T J - 4 8 i n c r e a s e d w i t h i n c r e a s i n g d o s e of T J - 4 8 f r o m 0.I to 1.0 g / k g / d a y , at w h i c h l e v e l a p l a t e a u w a s r e a c h e d . T h e d e g r e e of a c c e l e r a t i o n was largely dependent on both the period after MMC i n j e c t i o n a n d t h e d o s e of M M C . T h e e f f e c t s of TJ-48 on the production of s o l u b l e f a c t o r s s u c h as i n t e r l e u k i n s w i l l b e a l s o r e p o r t e d . These results suggest that TJ-48 has clinical significance as a s t i m u l a t o r of h e m a t o p o i e s i s in p a t i e n t s r e c e i v i n g M M C or p o s s i b l y o t h e r anticancer agents. Tsumura Research I n s t i t u t e for Pharmacology, 3586 Yoshiwara, Ami, Ibaraki 300-11 Japan

Y.Miyazawa~ M.Yamazaki~ S.Shimizu, J.E.Lai*, Y.C.Tun~* and N.u In an attempt t0 augment n0n-specific immunities in a tum0r-bearing host (C57BL/6 vs EL-4), we employed one kind of Japanese herbal medicine (Tsumura-Juzentaib0-t0 ;

T J - 4 8 ) as a b i o l o g i c a l r e s p o n s e m o d i f i e r . In t h i s s t u d y , immune r e a c t i v i t i e s were t e s t e d a b o u t the e f f e c t of a n t i b o d y f o r m i n g c e l l a g a i n s t T - d e p e n d e n t and - i n d e p e n d e n t antigen, abilities of m a c r o p h a g e s s u c h as c h e m o t a x i s , p h a g o c y t o s i s and i n t r a c e l l u l a r - k i l l i n g of b a c t e r i a and o v e r - a l l d e f e n s e immunity a g a i n s t b a c t e r i a l i n f e c t i o n b y t r e a t i n g mice w i t h t h i s remedy v i a o r a l a d m i n i s t r a t i o n . C h e m o t a c t i c a c t i v i t y of p e r i t o n e a l m a e r o p h a g e s was d r a m a t i c a l l y d e p r e s s e d w i t h i n a few d a y s a f t e r EL-4 transplantation, in many immune r e a c t i v i t y so f a r t e s t e d in t h e h o s t . T h i s d e c r e a s e d a c t i v i t y of m a c r o p h a g e s was t h o u g h t to r e n d e r t h e h o s t i m m u n o s u p p r e s s i v e , e s p e c i a l l y in c o m b i n a t i o n w i t h C y c l o p h o s p h a m i d e (CY). PFC v a l u e as w e l l as t u m o r - s i z e were s i g n i f i c a n t l y decreased, e s p e c i a l l y when the mice were i n j e c t e d i . p . w i t h CY. But a f t e r a d m i n i s t r a t i o n of t h i s remedy ( T J - 4 8 , l g / k g ) , PFC v a l u e s of b o t h IgM and IgG r e c o v e r e d to a b o u t the normal level. Together with the various activities of m a c r o p h a g e s , t h e o v e r - a l l p e r f o r m a n c e of t h i s remedy as a d e f e n s e immunity against systemic infection by Salmonella enteritides was evaluated. T h i s remedy s i g n i f i c a n t l y p r o l o n g e d the mean s u r v i v a l of t u m o r - b e a r i n g m i c e . D e p t . of S e r o l o g y , KANAZAWAMEDICAL UNIVERSITY, I s h i k a w a , J a p a n ~ D e p t . of B i o c h e m i s t r y , T a i p e i Medical C o l l e g e * , T a i p e i , R.O.C.

PP 12.12

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ASPECS OF JAPANESE KANPO (HERBAL) MEDICINE AS BBM. (I) ANTI-TUMOR EFFECT AND METASTASIS.

PROTECTIVE EFFECTS OF JUZEN-TAIHO-TO AGAINST NEPHROTOXICITY INDUCED BY CISPLATIN O. T. l i j i m a , S. Funo, Y. Kobayashi, H. Kuboniwa, Y. Fu jii and E. Hosoya We have reported that Juzen-taiho-to(TJ-48), one of Japanese kampo medicines, o f f e r s protection against the t o x i c i t y of mitomycin C(MMC) and Cisplatin(CDDP). TJ-48 prolonged the survival curves of mice given a lethal dose of MMC or CDDP and shifted the LD50s of these drugs to the r i g h t . TJ-48 also had beneficial e f f e ct s on the t o x i c e f f e c t s of MMC such as leucopenia, anemia, body weight loss as well as the atrophy of the t e s t i s , thymus and spleen. In t h is study, we examined the protective e f f e c t s of TJ-48 against the nephrot o x i c i t y induced by CDDP. 5mg/kg of CDDP was given to SD rats o n c e i n t r a p e r i t o n e a l l y , and TJ-48 was administered o r a l l y 7 times at a d a ily dose of l.O or 2.0g/kg from 3 days before CDDP u n t i l 3 days a f t e r CDDP. Body weight, organ weight, BUN and creatinine levels were evaluated and pathological studies of the kidney were performed on the 3rd, 5th and 7th day of CDDP. CDDPlevels in the serum and the kidney were also evaluated. TJ-48 markedly supressed the increase of BUN and c r e a t inine levels, and had beneficial e f f e c t s on body weight loss and the atrophy of the thymus, dose dependently. TJ-48 also reduced the severity of pathological changes such as d i l a t i o n of tubules, vacuolar degeneration and tubular necrosis of the $3 segment in the outer s t r i p e caused by CDDP. However, serum and kidney CDDP levels were not altered by the administration of TJ-48. These results suggest t h a t TJ-48 may be useful in preventing or reducing the nephrotoxicity induced by CDDP. Tsumura & Co. Research I n s t i t u t e f o r Pharmacology, 3586 Yoshiwara, Ami-machi, Inashiki-gun, Ibaraki 300-11 JAPAN.

N.Yamaguchi, M.Hamada, Y.Miyazawa, H.Koshimo, L.F.Wang*and Y.C.Tung~ In order to augment the decreased immune status of a tumor-bearing host (mouse lymphoma ; EL-a vs C57BL/6), one kind of Japanese herbal medicine (Tsumura-Juzentaiho~o ; TJ-48) was employed and its effect on specific anti-tumor activity was evaluated. In this communication, we focused on histological observation of local and central lymphoid organs and especially on metastatic loci of the liver and their life span in combination with Cyclophosphamide (CY) as the chemotherapeutic agent. This remedy (TJ-48, ig/kg, p.o.) was significantly effective especially when employed in combination with CY, in prolonging the life-span of tumor-bearing mice as well as enhancing the reduced macrophage chemotaxis. On histological analysis, ~acrophages were found to accumulate at the site of tumor inoculation where a massive area was necrotic in the experimental group. According to the winn test, peritoneal adherent cells were effective in prolonging the host life. Hepatic metastasis.were found in all the control at 2 weeks, including metastatic foci with malignant cells numbering more than 50. In contrast, in the TJ-48 group, an incidence of only 35% hepatic metastasis was found and in no metastatic locus were more than 50 malignant cells present. Dept. of Serology, KANAZAWA MEDICAL UNIVERSITY, Ishikawa, Japan & Dept. of Biochemistry, Taipei Medical College*, Taipei, R.O.C.

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EFFECT OF JUZENTAIHO-TO (TJ-48, CHINESE HERBAL MEDICINE) ON CANCERTHERAPY IN EXPERIMENTAL ANIMALS K. Komiyama, Z. Yah9 and I. Umezawa Previous studies shown that TJ-48 potentiated antitumor a c t i v i t y of mitomycin C (MMC)on experimental tumor (Jpn. J. Cancer Chemothera. 15, 1715, 1988). Thereafter , p o t e n t i ation of the therapeutic e f f e c t of MMC and hyperthermia on tumor and reduction o f immunotoxicity of MMC or r a d i ation by TJ-48 were investigated in experimental animals. Mouse sarcoma 180 tumor c e l l s were inoculated sc i n t o the footpads of ICR mice on.day 9~. TJ-48 was qiven (days ]-50) o r a l l y . On appropriate, day~^(oa~s 5~ 8~ 12, 15 and 19), mice were aam~nis~era MML [J mg/Kg/uay) ip ana treated with hyperthermia (43~ 30 min). TJ-48 markedly p o t e n t i ated the e f f e c t s of the combined use o f MMC and hyperthermia. Simila~ r e s u l t s were observed against BI6 melanoma inoculated into BDF1 mice. Tumor-bearing f e e t of mice treated with MMC (days 5, 8, 12, and 15, 1.5 mg/kg/day) and TJ-48 (days 1-40, 500 or 2000 mg/kg/day) were amputated on day 14, the S180 tumor was r e - i n o c u l a t e d sc i n t o the a x i l l a r y region on day 19, and the subsequent tumor grwth was observed. These r e s u l t s indicated t h a t tumor growth and the incidence of tumors in the non-treated group were suppressed. However, a marked tumor growth was observed in the group administered MMC. In contrast, tumor growth and the incidence were suppressed in the group given MMC plus TJ-48 when compared with MMC alone. S180 tumor-bearing f e e t of mice treated with TJ-48 (days 1-40) amputated on day 6, mice were received 350 rad of Co60 on day 7, the S180 tumor was r e - i n o c u l a t e d sc i n t o the a x i l l a r y region on day 12, and the subsequent tumor growth were observed. A remarkable tumor growth was observed in the group treated with the r a d i a t i o n , but the growth was suppressed in the TJ-48 treatment group. These r e s u l t s suggest that TJ-48 not only potentiates the combined e f f e c t s of MMC and hyperthermia but also reduces and/or eliminates the immunotoxicity of MMC and r a d i a t i o n in the host. The Kitasato Inst. 5 - 9 - I , Shirokane, Minato-ku Tokyo, 108

PRCFII~CTIVE EFFECT OF JUZENTAIHO-TO ON RfiNAL %X3XIC SIDE EFFECTS OF CIS-DI;LMMINFI)ICIiLOROPIATINT.91INMICE K.Sugiyama, M.Yokota, H.Ueda, and Y.Ichio [Introduction] In recent years, the treatment of cancers with combined methods of Japanese Kampo medicine and western medicine has made much progress. Clinical and laboratory studies show that Juzentaiho-to(TJ-48, ShiQuan-Da-Bu-Tang in Chinese) may have the effect of protecting the toxic side effect of anti-cancer drugs such as cis-dia~inedichloroplatinum(CDDP), 5-fluorouracil, mitomycin C,etc. Effect of oral administration of TJ-48 on the renal toxicity of CDDP was examined by using ddy mice. Futhermore, a study was conducted to elucidate the activeprinciples in TJ-48. [Results] Daily consecutive oral administration of TJ-48 at a dosage of ig/kg/day completely inhibited the renal toxicity(indicated by an increase in blood urea nitrogen value) in mice which were given of daily consecutive i.p. administration of CDDP(3mg/kg). Constituent crude drugs of TJ-48, Angelicae Radix(400mg/kg), Cinnamomi Cortex (82mg/kg), Astragali Radix(540mg/kg), Hoelen(35mg/kg), and Glycyrrhizae Radix(540mg/kg) showed inhibitory effect on the renal toxicity of CDDP. As a result of the studies on the active principles in Angelicae Radix, an amorphous powder has been isolated as the main active principle. Daily consecutive oral administration of the powder at a dosage' of ]_Tng/kg/day inhibited the increase in blood urea nitrogen value. The chemical structure of the powder is still being studied. School of Pharmaceutical Science, University of Shizuoka, 395 Yada, Shizuoka, 422 Japan

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SUPPORTINGTHERAPYOF JUZENTAIHO-TO IN ADVANCEDBREAST CANCER PATIENT I. Adachi, 7. Watanabe, J. Cheng and I(. Abe The p r e s e n t study was designed to a s s e s s the u s e f u l l n e s s

CLINICAL IMPROVEMENT OF STROKE PATIENTS TREATED BY ORENGEDOEU-TO H. Nagasawa and K. Kogure A traditional Kampo prescription, Oren-gedoku-t0 has been used for the treatment of various clinical symptoms associated with cerebral apoplexy. 0ren-ged0ku-t0 is composed of four crude drugs in fixed proportions, each of which has several major components with different pharmacological properties. We reported long-term administration of 0ren-gedoku-t0 (300 mg/kg/dayl had effects on increase of cerebral blood flow to the chronic brain ischemia and resulted in the reduction of isehemic brain area in rats (i). In the present study, we examined the effects of 0renged0ku-to on stroke patients clinically. Thirty patients with cerebral vascular diseases, aged from 56 to 89, were treated by oral administration of 0ren-gedoku-to (7.5 gm/daY) for three months. Before and after the treatment, neurological examinations including Japanese intelligence test which was similar to mini-mental state t e s t , and e v a l u a t i o n of a c t i v i t i e s of d a i l y l i v i n g (ADL) were performed. After the t r e a t m e n t , a p p r o x i m a t e l y 70 ~ patients improved some of t h e i r n e u r o l o g i c a l symptoms, ADL, and especially mental a c t i v i t y . For twenty p a t i e n t s with dementia, the mean s c o r e ( v a l u e * SD.) was improved from 8.8 • 4.7 (de me nt i a ) to 11.4 • 5.1 ( p r e d e m e n t i a ) u s i n g the Japanese i n t e l l i g e n c e t e s t ( f u l l marks : 32.5) significantly (p
of o r i e n t a l herbal medicine ( J u z e n t a i h o - t C T J - 4 8 ) o o m b i n e d with chemo-endocrine therapy f o r t r e a t m e n t of advanced b r e a s t cancer, using as major endopoints s u r v i v a l and q u a l i t y of l i f e . They had r e c e i v e d no p r e v i o u s s u r g i c a l o p e r a t i o n of g a s t r o i n t e s t i n a l organ, were l e s s than 70 years old and performance s t a t u s (ps) l e s s than 3. The p a t i e n t s were randomized with the envelope method, d i v i d i n g i n t o e i t h e r h or B-group. In A - g r o u p , t h e y t r e a t e d withTJ-*~ combined with chemo-endocrine therapy. In B-group, they were t r e a t e d with only c h e m o - e n d o o r i n e therapy. Between May 1985 and December 1987, 130 p a t i e n t s were entered to t h i s t r i a l , 119 p a t i e n t s were e v a l u a b l e , 58 p a t i e n t s belonged to.A group and 61 to Bgroup. The p a t i e n t s c h a r a c t e r i s t i c s of age, ps, d i s e a s e f r e e i n t e r v a l , e s t r o g e n r e c e p t o r s t a i : u s , dominan% s i t e of m e t a s t a s e s , were w e l l b a l a n c e d in both t h o s e g r o u p s . '['here was no s i g n i f i c a n t d i f f e r e n c e in the r e s p o n s e r a t e s between A- and B-groups. The s u r v i v a l r a t e up t o 38 months was not s i g n i f i c a n t l y d i f f e r e n c e between two g r o u p s , but in-f~'-~-SHO group, the s u r v i v a l was s i g n i f i c a n t l y h i g h e r in t h e p a t i e n t s b e l o n g e d to t he Agroup (Greenwood, p
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PP 12.19 PHARMACOLOGICAL OF GANODERMA

PP 12.21 AND THERAPEUTIC EFFECTS

T.T.Bao et al= Ganoderma, one of the valuable traditional Chinese medicinals, was described as nontoxic panacea in Chinese medical classics. It was recorded to be beneficial to all viscera and to be able to retard aging and prolong life when taken regularly for long period Of time. Two kinds of Ganoderma injections, G731 & G741 were developed by our Institute. They were found to be useful in relieving symptoms of atrophic myotonia and progressive muscular dystrophy without noticeable side effect. G741 was reported later to be effective in treatment of collagen diseases ( such as dermatomyositis, dermatosclerosis and lupus erythematosus) and alopecia areata. Pharmacologic studies showed that in mice after a s.c. dose of eisner inseetions , spontaneous motor activity was denreased, barbital sleeping time prolonged, pilocarinduced salivation decreased, nicotine induced convulsion and death prevented and rectal temperature lowered. G741 was found to promote the phagocytosis of m a c r o f u g e but inhibit DNA synthesis and transformation of T lymphocytes. Adjuvant arthritis on rats was inhibited by the drug but the loss of thymus weight was neglectable. Both injections showed hypocho!esterolemic and other cardiovascular activities in animal experiments.

PROTECTIVE EFFECTS OF T J - 9 6 0 ON HIPPOCAMPAL NEURON DAMAGE DUE TO CEREBRAL ISCHEMIA AND COBALT-INDUCED EPILEPSY A.Ishige, K.sekiguchi, A.Sugimoto, M.yuzurihara, S. I i z u k a , K. S u d o , E.Hosoya a n d E . S u ~ a y a TJ-960, a J a p a n e s e Kampo P r e s c r i p t i o n , is a mixture of nine herbal drugs which shows antiepileptic effects in intractable epileptics. We p r e v i o u s l y demonstrated inhibitory effects on seizures of amygdaloid kindled cats and pentylenetetorazolinduced EEG p o w e r s p e c t r u m c h a n g e s . TJ-960 showed inhibitory effects o n EEG c h a n g e s o f the cobaltinduced epilepsy model which could not be inhibited by various anticonvulsant drugs. To elucidate the characteristics of the mechanism of anticonvulsive action of TJ-960. effects of TJ-960 on hippocampal neuron loss due to brain ischemia and cobalt-induced epilepsy were examined. Brain ischemia in rats was prepared by bilateral occlusion of the carotid and vertebrate arteries. The cobalt epilepsy model was prepared by applying cobalt powder to the left cerebral cortex of rats. From two days after cobalt application, hlppocampal neuron loss in the CAI area began without genera llzed convulsions, and almost complete neuron loss was observed by the 20th day. Prior administration of TJ-960 from one month before cobalt application completely inhibited cobaltinduced hippocampal neuron loss. 5-10 min brain ischemia produced complete hippocampal neuron loss in the CAI area. Prior administration of T J - 9 6 0 resulted in complete protection against hippocampal neuron damage due to cerebral ischemla. these findings suggest that TJ-960 has excellent protective action against neuron damage in epileptics and also that caused b y cerebral ischemia.

Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing 100050.

Research Institute for Pharmacology, TSUMURA & Co., 3586 Yoshiwara, Ami-machi, Ibaraki-ken, 300-11 and *Department of Physiology, Kanagawa Dental College, Yokosuka. 238, Japan.

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THE CLINICAL PHARMACOKINETIC STUDY HYDROCLORID TETRAMETHYLPYR~ZINE

OF THE

Y.C. LOU, _X.E- LIU Tet~amethylpyrazine (TMDZ), a pure alkaloid isolated from traditional chinese herb, Ligastum Wellichii Franchet, has been widely used in our country. By using HPLC with ~ reverse-phase column ~nd UV detector ( 280 mn ) the determination of TMPZ serum concentration has been investigated in our Lab. 7 patient with acute cerebral ischemia aged 5885 years were given initial intravenous infusion of 80mg of TMPZ in 500ml of 5% glucose solution. 12 normal volunteers aged 20-39 yeazs weu~ given intramuscularly a single dose of 40mg of TMPZ. The blood samples were collected at various times after the drug administration. Yhe pharmacokinetic parameters were obtained by using MCPKP ~omputaz program. Discussion: 1. The HPLC method for dsterminin~ the TMPZ serum ~oncentm~tion is able to satisfy the need in experimental and clinical studies. 2. TMPZ was rapidly absorbed and ~liminated. It's half lives of eliminatCon were 1.61 ( V infusion ) and 2.10 h ( IM ) respectively. 3. Theremare existed interindividual vmriations in phsrmaookinetics of TMPZ in patients and in normal subject~. 4. We suggested that patients with cerebral ischemia diseases should be given TMPZ orally after the V infusion in order to maintain the drug ~oncentratian and probably the effctiveness. Department of Pharmacology of Beijing Medical University, Beijing, Peapla's Republic of Chlna

INDIGENOUS DRUGS USED AS HYPOLIPIDAEMIC AGENTS S,Dwivedi Search for a effective and safe hypolipidaemie agent to prevent ischaemic heart disease is one of the major thrust area in contemporary clinical research. Several indigenous indian drugs have been mentioned to be effective in hyperlipidaemia. Notable among them are Allium Sativum, Allium Seppa, Commiphora mukul, Emblica officinalis, Inula racemosa, Ocimum sanctum, Saussurea lappa clarke, Terminalia arjana, Terminalia bellerica and Terminalia chebula etc. The hypolipidaemic property of ~.arjuna, I.racemosa and ~. lappa clarke has so far not Been extensively investigated. Present work was undertaken to evaluate thebeneficial effect of these three indigenous drgus in isoproterenol induced experimental myocardial ischaemia in 35 rabbits as well as in 90 ischaemic heart disease patients. ~. racemoaa aad ~. arjuna were found to be effective hypolipidaemic agents in experimental animals. However, in clinical cases the hypolipidaemic action could be observed in T. arjuna treated ischaemic heart disease patients only. In addition to its hypolipidaemie Property T. arjuna also produced significant weight reduction in obese individuals. None of these drugs had any significant side effects. Department of Medicine, Kasturba Medical College and Hospital, Maaipal - 576 119, India.

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I N V E S T I G A T I O N OF P H A R M A C O L O G I C A L A N D MICROBIOLOGICAL A C T I V I T I E S OF STRIGA SENEGALENSIS, A P L A N T USED IN H E R B A L THERAPY O F MALARIA D. S. O g u n l e y e t J. A. Onaolapo and J. Auta The use of h e r b s / h e r b a l p o r t i o n s in treatment of certain diseases is gaining p r o m i n e n c e due to the twin effect of high cost and failure of synthetic/conventional drugs in o r t h o d o x clinical practice. A herbal portion containin~ Stri~a sensgalensis (F. S c r o p h u l a r i a c e a s e ) extract is used among the H a u s a / F u l a n i communities in the Sahelian region of West Africa in the treatment of m a l a r i a without e s t a b l i s h e d scientific basis. P h a r m a c o l o g i c p r o p e r t i e s of S. senegalensis ("Kudiji/Wutawuta") were i n v e s t i g a t e d in animals. Aqueous extract of plant caused c o n t r a c t i o n (guinea pig) and r e l a x a t i o n (rabbit) gut smooth muscle, a r e s u l t a n t fall in b l o o d pressure (cat) and reduced pyresis in rats i n f e s t e d with p l a s m o d i u m b e i ~ n e i oe1~nei. The a g a r : i m u p T p ~ m~tfiSd was used in evaluating the m i c r o b i o l o g i c a l activities. Sterile aqueous extract Of plant was active against all tested isolates including P s e u d o m o n a s aeruginosa, B a c i l l u s subtilis and Candida albicans which was compared with c o m m ~ y available p e n i c i llin disc (2ug). There was reduced p a r a s i t e m i a in P l a s m o d i u m - i n f e s t e d rats. F a c u l t y of P h a r m a c e u t i c a l Sciences, A h m a d u Bello University, Zaria, Nigeria.

INHIBITORY EFFECTS OF TJ-960 ON SEIZURE-RELATED CHANGES OF SINGLE IONIC CHANNELS IN PRIMARY CULTURED NEURONS OF MICE A.Sugaya, T.Tsuda, K.Yasuda, *E.Sugaya, *T.Takagi, *K.Kajiwara, *J.Komatsubara & *H.Takagi We previously demonstrated anticonvulsant effects of T]-960 (SK), a mixture of nine herbal drugs, Bupleuri Radix, Scutellariae Radix, Pinelliae Tuber, Paeoniae Radix, Cinnamomi Cortex, Glycyrrizae Radix, Zingiberis Rhizoma, Ginseng Radix and Zizyphi Fructus. This herbal drug inhibited pentylenetetrazol (PTZ)-induced bursting activity of snail neurons and PTZ-induced intracellular calciumrelated pathological phenomena. To elucidate the detailed anticonvulsant mechanism of TJ-960, we examined the effects of TJ-960 on PTZ-induced single ionic channel changes of primary cultured neurons of mice. Primary cultured cerebral cortical neurons of ddY mice and those of the epilepsy model animal, El mice were used. By application of PTZ, primary cultured cerebral cortical neurons of d d Y mice showed bursting-type open-close state of a single potassium channel in the cell-attached patch recording. By application of TJ-960, PTZ-induced changes were completely inhibited. The single potassium channel of primary cultured cerebral cortical neurons of El mice showed spontaneous bursting-type open-close state or high susceptibility to PTZ. Prior application of T]-960 completely normalized these pathological changes in the El m o u s e single ionic channel. The above-mentioned results suggest that T]-960 has normalizing effects on the seizure-related changes of a single ionic channel of the cerebral cortical neurons. Fuculty of Pharmaceutical Sciences, Josai University, Sakado, Saitama-ken, 350-02, Japan and *Department of Physiology, K a n a g a w a Dental College, Yokosuka, 238, Japan

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REDUCED TERATOGENICITY OF SODIUM VALPROATE WITH C0ADMINISTRATION OF TJ-960 IN RATS. S. Minematsu, M. TaM, M. Takahashi, H, Horiuohi, Y. Fujii and E, Hosoya. TJ-960 is a new Kampo description which combines Sh6saiko-t6 with Eeishikashakuyaku-t6 and which has potent a n t i convulsant action. I t is well known that anticonvulsant drug (ACD) has some teratogenic effects. TJ-960 wil l be administered to patients together with other ACD(s). In t hi s point of view, influence of TJ-960 on the rat fetus was examined, in particular, when co-administered with sodium valproate(VPA). TJ 960(1000 or 3000mg/kg) was administered to pregnant SD r a t s by garage with or without VPA(400mg/kg) during organogenie period(Day 7 to 17 of gestation). All the fetuses were i s o l a t e d from dams by Caesarian section on Day 21. After the external observation, about 2/3 of the fetuses in each l i t t e r were immersed in 95% ethanol for the preparation of s k e l e t a l specimen and the remains were fixed in gouin's s o l u t i o n for visc eral examination. The effects of VPA and TJ-960 on f e t a l skeletons were evaluated by three categories, namely ossification, variation and anomaly. TJ-960 i t s e l f revealed no teratogenic action. The delayed o s s i f i c a t i o n induced by VPA was recovered when TJ-960 was co-administered. As the skeletal variation, VPA lead to the r e t a r d a t i o n of thoracic vertebral center and sternum, rudi mentary cervical and 13th rib, 14th rib and so on. These v a r i a t i o n s were also reduced with the co administration of TJ-860. VPA induced skeletal anomalies such as absence of c e r v i c a l vertebral center, fissure of thoracic and lumber vertebra and sternum, and fused and wavy ribs. TJ-900 decreased the frequency of these appearances. In the external and visceral examinations, TJ-960 had almostly no effect on the incidence of anomalies. However, the body weight loss induced by VPA was improved with the co-administration of TJ 960. From these results, i t is concluded that TJ-960 has a high inhibitory effect against the t e r a t o g e n i c a c t i o n of VPA. Research Institute for Pharmac01ogy, TSUMURA & CO., 3586, YosMwara, Ami-machi, Ibaraki 300-11, Japan.

NORMALIZING EFFECTS OF TJ-960 ON ABNORMALITIES OF PRIMARY CULTURED NEURONS OF THE EL MOUSE

E.Sugaya, H.Takagi,

K.Kajiwara, T.Taka@i, J.Komatsubara, *A.Sugaya *T.Tsuda, and *K.Yasuda

The E1 mouse i s an e p i l e p s y model a n i m a l w hi ch i s h i g h l y s u s c e p t i b l e to c o n v u l s i o n s . We p r e v i o u s l y d e m o n s t r a t e d the a n t i c o n v u l s i v e a c t i o n of T]-960, a m i x t u r e of n i n e h e r b a l d r u g s , on t he c o n v u l s i o n s of E1 mice. We a l s o d e m o n s t r a t e d p r o t e c t i v e e ffe cts of T]-960 on the c y t o c h a l a s i n B d i s t o r t i o n of n e u r i t e s of celutured neurons. To c l a r i f y the m e c h a n i s m of th e anticonvulsive effect and the protective effect of TJ-960 against neurite damage, effects of T]-960 on primary cultured neurons from El mice were examined. Primary cultured neurons from the cerebral cortex of embryonic and new born E1 mice as well as ddY mice were used. The primary cultured neurons from the cerebral cortex of E1 mice showed underdevelopment of the n e u r i t e e x t e n s i o n c ompa re d w i t h t h a t of ddY mice. The GD^, GTlb a n d GQ g a n g l i o s i d e s of p r i m a r y c u l t u r e dd n e u r o n s from t~ b 1 8 - d a y - o l d E1 mouse was g r e a t l y d e c r e a s e d c ompa re d w i t h t hos e from the ddY mouse. When a c u l t u r e was performed w i t h medium c o n t a i n i n g TJ-960, t h e s e g a n g l i o s i d e s were i n c r e a s e d and neurite extension was normalized. These findings together with the previous results suggest that T]-960 has a normalizing effect on neuron development and a protective effect on neuron damage. This is probably one of the reasons w h y TJ-960 shows improvement of emotional disturbances of epleptics in clinical use.

Department of Physiology, K a n a g a w a Dental College, Yokosuka, 238, Japan and *Fuculty of Pharmaceutical Sciences, Josai University, Sakado, Saitama-ken, 350-02, Japan

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COMBINATION THERAPY BY SURGICAL EXCISION AND A K A M P O M E D I C I N E (ORAL A D M I N I S T R A T I O N O F A J A P A N E S E H E R B A L DRUG) OF T R A N S P L A N T E D M e t h - A F I B R O S A R C O M A IN B A L B / C M I C E N. M a r u y a m a , H. k a w a m u r a , N. T a k e m o t o , S. S h i n o h a r a , Y. K o m a t s u , M. A b u r a d a , E. H o s o y a Juzentaiho-to (TJ-48), o n e of K a m p o m e d i c i n e s , is the e x t r a c t of T e n m e d i c i n a l p l a n t s w h i c h are mixed, d e c o c t e d a n d dried, a n d ~s a d m i n i s t e r e d orally. In T h i s study~ t h e T r e a t m e n t of M e t h - A t u m o r - b e a r i n g m i c e w i t h T J - 4 8 in c o m b i n a t i o n w i t h s u r g i c a l e x c i s i o n (SE) w a s e x p e r i m e n t a l l y i n v e s t i g a t e d . Mice w e r e i n o c u l a t e d i n t r a d e r m a l l y (i.d.) w i t h M e t h - A (2.5 x I0 ~ cells) into T h e r i g h t f l a n k a n d 7 d a y s later SE of t h e e s t a b l i s h e d s o l i d Tumors was performed. A f t e r 7 m o r e days, M e t h - A (1.25 x I05 cells) w a s i.d. r e i n o c u l a t e d into T h e left f l a n k of t h e s a m e m i c e a n d the g r o w t h of r e i n o c u l a t e d T u m o r w a s o b s e r v e d . T r e a t m e n t of m i c e w i t h b o t h T J - 4 8 a n d SE e x h i b i t e d a s i g n i f i c a n t i n h i b i t i o n in tumor-growth a n d p r o l o n g a t i o n of s u r v i v a l t i m e c o m p a r e d To T r e a t m e n t w i t h e i t h e r T J - 4 8 or SE alone. C o m p l e t e r e g r e s s i o n of T u m o r w a s s e e n in 4 of ? m i c e in T h e g r o u p of c o m b i n a t i o n Therapy. T J - 4 8 w a s f o u n d to e n h a n c e b o t h humoral (antibody production) and cell-mediated ( t u m o r - s p e c i f i c DTH) immunity. In W i n n assay, T h e tumor-growth w a s r e m a r k a b l y i n h i b i t e d w h e n Meth-A cells were admixed with spleen cells f r o m m i c e T r e a t e d w i t h T J - 4 8 a n d SE. These r e s u l t s s u g g e s t that T h e i m m u n o p o t e n t i a t i n g a c t i v i t y of T J - 4 8 is s t r e n g t h e n e d w h e n c o m b i n e d w i t h SE w h i l e T J - 4 8 h a s s o m e a c t i v i t y b y i t s e l f a n d T h a t T J - 4 8 m a y b e u s e f u l for T h e T r e a t m e n t of s o m e k i n d of c a n c e r . T s u m u r a R e s e a r c h I n s t i t u t e For P h a r m a c o l o g y , 3 5 8 6 Yoshiwara, Ami, I b a r a k i 300-11, Japan.

FREQUENCY DEPENDENT MECHANICAL BEHAVIOUR OF LUNGS : A NEW NONINVASIVE TEST FOR THE RESPIRATORY PHARMACOLOGY IN LARGE ANIMALS. P. Gustin~ F.J. Land~r~ F. Lombs and P. Lekeux The respiratory pharmacology is largely unexplored in large mammals. This can be partially explained by the fact that methods used in small laboratory animals do not easily fit to large animals. The purpose of this study was to show that the forced oscillation technique (F.O.T.) can be used in cattle tn perform respiratory clinical trials. Fifteen bulls weighing b e t ~ e n 180 and 360 kg were investigated. The F.O.T. was used to measure the total respiratory resistance (Mrs) and reactance (Xrs) st frequencies from 6 to 26 Hz (Gustin et al., 1988). Measurements were performed during end after naturally occuring "Shipping Fever" pneumonia. Ceftiofur (U-64279E) (1 mg/kg IM; n=lO, group A) and oxytetracvcline (10 mg/kg; n=5; group B) were given to the animal during three days. A large increase of Mrs, of the resonant frequency, a decrease of Xrs, a marked negative frequency dependence of Mrs were recorded in the initial stage of the disease. These parameters retursed to normal values 7 days later. However, the recovery was more marksd in group A than in group B. In the latter, Mrs values remained high on day J7 and the somatic growth was decreased as compared to reference values. Our results show that moderate Shipping Fever pneumonia induces an acute small and large airway obstruction and that an appropriate antibiotic therapy can reduce the functional consequences of the disease. The F.O.T. is a non-invasive method which could be very useful to follow the evolution of a respiratory disease and to perform therapeutic test in large animals. Gustin et al. J. Appi. Physiol. 64; 1786-1791, 1988.

PP 12.28

PP 12.30

THE EFFECT OF ASI AND SKI ON ANTI-HEMOLYSIS AND ANT1-0 XI DATI ON Y i n - d i ZHANB, J i a n - p i n 9 SHENG, You-l i n 9 WANG De-xing L I 92 mice were grouped and given 25 mg/kg, SK (Astrasieversianin e x t r a c t e d from A s t r a g a l u s s i e v e r s i a n u s Pull ) 25 mg/kg, ASI ( A s t r a g a l u s Saponins I d i s o l a t e d fron~ A s t r a g a l u s rnembranaceus ) PO f o r 4 days, I t was shown t h a t MDA was s i g n i f i c a n t l y decreased and GSH was markedly i n creased i n t h e i r l i v e r . Tenuigenin was known t o f a c i l i t a t e hemolysis, i t s e f f e c t was t e s t e d i n a d i f f e r e n t incubated time ( 2, 4, 24 hrs ) i n the presence o f ASI ( 0.02, 0.04, 0.06 n,M ) , SK ( 0.008, 0.016, 0.024 raM ) r e s u l t i n g in a m a r k e d decrease in h e m o g l u b i n ( Hb ) in h u m a n e r y t h r o c y t e s , d e c r e a s e in Hb w a s d e p e n d e n t on t h e concet~tration c,f ASI and SK. 85 norn',al male mice were s e p a r a t e d l y given 12.5, 25 mg/kg.d, ABI and 6, 12 mg/ kg.d, SK x 14-16 days r e s u l t i n g i n s i g n i f i c a n t i n c r e a s e i n red c e l l s u p e r o x i d e dismutas a c t i v i t y ( SOD ). I t s a c t i v i t y rose from 5135+834 t o 9785+ 464 i n Kunming spe,zies and from 4326+965 t o 6336+ 684 ( +S. D. ,u/g Hb ) maximum i n C~TBL/6 species. These r e s u l t s showed t h a t the increased SOD a c t i v i t y owing t o ASI and SK a d d i t i o n may be u s e f u l f o r r e s i s t a n c e t o hemolysis induced by Tenuigeni~. I t suggested t h a t ASI and SK had a a n t i - o x i d a t i v e e f f e c t s i n c e the content o f SOD was enhan,zed and and t h e l e v e r o f MDA was lowered by them. The basic machenism may be an important b e a r i n g upon d i f f e r e n t diseases rendered w i t h equal " Huangqi" i n Chinese T r a d i t i o n a l Medicine Theory. D e p t . o f Pharmacology, Nanjing Medical Col lege, Nanjing, 21(:)005, The P e o p l e ' s Republic o f China

COMPARATIVE EFFECTS BETWEEN BUTAMIRATE CITRATE (BC) AND CODEINE PHOSPHATE (CP) ON THE ISOMETRIC CONTRACTION (IC) OF THE ISOLATED HEMIDIAPHRAGM OF THE RAT M, Prostr~n, V.M. VaraQir S. Radulovir M. Pokraiac and S. Miloyanovir Some d r u g s acting on t h e r e s p i r a t o r y system, e.g. b e t a - a d r e nerglc agonists and aminophylline, produce potentiation of t h e IC of t h e isolated hemidtaphragm of t h e rat. Theophylline has also been shown to improve diaphragmatic f u n c t i o n in man. This t y p e of action may p r o v i d e additional t h e r a p e u t i c benefit of d r u g s acting on t h e r e s p i r a t o r y system, because in r e s p i r a t o r y i n s u f f i c i e n c y t h e r e s p i r a t o r y muscles may fail in much t h e same way as t h e h e a r t muscle fails. BC is a nonnarcotic a n t i t u s s i v e d r u g . I t is known t h a t all a n t i t u s s i v e s are usually contraindicated in r e s p i r a t o r y failure. I t was t h e r e f o r e of i n t e r e s t to i n v e s t i g a t e t h e action of BC on t h e isolated diaphragm of the rat, a muscle known to participate in the r e s p i r a t o r y f u n c t i o n . Also, it was i n t e r e s t i n g to compare t h e effect of BC with t h e effect of CP, a narcotic a n t i t u s s i v e d r u g . I t was f o u n d t h a t both BC and CP produce a c o n c e n t r a t i o n - d e p e n d e n t potentiation of t h e IC of t h e Isolated hemidiaphragm of t h e r a t d u r i n g d i r e c t electrical stimulation. The effect of BC was s t r o n g e r than t h e effect of CP d u r i n g d i r e c t electrical stimulation. BC also produces a v e r y s t r o n g potentiation of t h e IC d u r i n g i n d i r e c t electrical stimulation, while CP produces a weak potentiation of t h e IC. In a calcium-free medium, made by omitting CaCI 2 and by adding di-Na-EDTA, both substances failed to produce any change of t h e IC of the isolated hemidiaphragm of the rat. The mechanism of BC action remains to be elucidated. Some of its c h a r a c t e r i s t i c s are similar to those of t h e betaa d r e n e r g i c agonists and of AMPh, substances known to mobilize t h e e n e r g y fuel. The whole molecule of BC is of f u n d a mental importance f o r p r o d u c i n g potentiation of t h e IC of t h e hemidiaphragm, t h e c i t r a t e p a r t of t h e molecule being o n l y a c o n t r i b u t i n g factor. Because t h e o b s e r v e d action of BC may be clinically a beneficial c h a r a c t e r i s t i c , the effects of both BC and CP were compared in a double blind controlled clinical s t u d y (40 pts).

Chaires de Pharmaeelogie st de Physiologie 9 Facult~ de M~deeine V6t~rinaire, (ULg), 45 rue des V@t@rinaires B-f070 Bruxelles BelgiqL~.

Dept. of Pharmacology, Faculty o f Medicine, P.O.Box 662, 11000 Belgrade, Yugoslavia.

A 281

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PP 12.33

BEONCHODILATING ACTIVITY AND TOLERANCE OF HU 42173 IN ASTHMATIC PATIENTS. A. Lu~ie, F. Bompart, Ph. Vivet, D. de Lauture, L. Darchy, A. Venot, J. Marsac, G. Strauch. RU 42173 is a new beta-2-agonist chemically unrelated to existing beta-2-agonists. A double blind cross-over placebo-controlled randomized study was performed in 12 asthmatic adults to assess bronchodilating activity and tolerance for 8h after a single 0.25 mg oral dose of a solution of HU 42173. Bronchodilation was assessed by measurement of the forced expiratory volume in Isec(FEVl) (table). Heart rate (bpm) and blood pressure (mmHg) were measured and tremor was clinically appreciated. FEVI measurements (m • s.e.m.)

THE E F F E C T OF K C - 4 0 4 , A N E W A N T A G O N I S T OF ON ALLERGEN-INDUCED LATE BRONCHOCONSTRICTION M. A d a c h i , H. H o s h i n o , H. K o b a y a s h i , S. Konno, A. O k a z a w a , Y. Okada, T. S u g a n u m a , S. M a r u y a m a , and T. T a k a h a s h i Allergen-induced bronchoconstrictive responses w e r e e x a m i n e d in g u i n e a p i g m o d e l , a c t i v e t y sens i t i z e d by i n h a l a t i o n of a e r o s o l i z e d o v a l b u m i n (OA), w h i c h s h o w e d r @ p r o d u c i b l e l a t e b r o n c h i a l responses(LBR). O A - c h a l l e n g e w a s p e r f o r m e d u n d e r c o v e r of m e p y r a m i n e t h r o u g h t h e i n h a l e d r o u t e in s p o n t a n e o u s breathing without anesthesia. The respiratory r e s i s t a n c e ( R r s ) was m e a s u r e d b y the o s c i l l a t i o n m e t h o d for as l o n g as 96 hrs a f t e r O A c h a l l e n g e . T w e n t y - t w o of 22 g u i n e a p i g s d i s p l a y e d i m m e d i a t e b r o n c h i a l r e s p o n s e s ( I B R ) , f o l l o w e d b y 2 or 3 p h a s e L B R that p e a k at 6-8 h r s and 24 hrs a f t e r OA. E x a m i n a t i o n of b r o n c h o a l v e o l a r l a v a g e f l u i d (BALF) r e v e a l e d a s i g n i f i c a n t i n c r e a s e in n e u t r o p h i l s at 1 h (P<0.01) and e o s i n o p h i l s at 7 hrs and 96 hrs (each P<0.01) a f t e r O A c h a l l e n g e . OA-challenge induced airway hyperresponsiveness to h i s t a m i n e (P<0.01) a t 96 hrs that w a s a s s o c i a t e d w i t h a s i g n i f i c a n t i n c r e a s e in e o s i n o p h i l s (P<0.01) in B A L F c o m p a r e d w i t h at 7 hrs l a v a g e s . The i n c r e a s e s of Rrs in L B R w e r e i n h i b i t e d a l m o s t c o m p l e t e l y b y the p r e t r e a t m e n t of K C - 4 0 4 , w h i c h is r e p o r t e d to h a v e the a n t a g o n i s t i c action against LTC4/D4. The F i r s t D e p a r t m e n t of I n t e r n a l M e d i c i n e , S c h o o l of M e d i c i n e , S h o w a U n i v e r s i t y , 1-5-8, H a t a n o d a i , S h i n a g a w a - k u , T o k y o 142, J A P A N

0

(L) 1.7• %pred 47• (L) 1.7• %pred 47•

Time (hours) after dosing O.5 i 1.5 RU 42173 treated ~atients 2.1• "2.2• -2.3• "60~6 *63• "64• Placebo treated patients 1.8• 1.8• 1.8• 51• 52• 50•

2

4

*2.3• *64•

2.0• *58•

1.9• 53•

1.8• 51•

* : P <.05 when compared to placebo; pred : predicted values. Significant FEVI rise occured during 4h after dosing. Maximal increase in heart rate and decrease in diastolic blood pressure were respectively observed at 1.5 and lh after RU 42173 administration (heart rate : HU 42173 : 76~3, placebo : 66• p <.05, diastolic blood pressure RU 42173 : 67• placebo : 73~3 P <.05). Slight tremor was observed in 2 HU 42173 treated patients. Using the actual over predicted FEVI ratio reduced FEVI interpatients variability and increased the power of the comparisons. In conclusion, HU 42173 showed an effective bronchodilating effect. 0nly minor side effects were noted. IRT-ECLIMED - Hbpital COCHIN 75014 PARIS FRANCE and ROUSSEL UCLAF, ROMAINVILLE FRANCE.

PP 12.32 THE E F F E C T I V E N E S S OF R E P E T I T I V E A D M I N I S T R A T I O N OF FENOTEROL METERED DOSE INHALATION(MDI) WITH BECLOMETEASONE DIPROPIONATE INHALATION(BDI) T. S u q a n u m a , M. A d a c h i and T. T a k a h a s h i The e f f e c t i v e n e s s of r e p e t i t i v e a d m i n i s t r a t i o n of F e n o t e r o l MDI (3 p u f f s / d a y or 6 p u f f s / d a y ) w i t h B D I ( 4 5 0 ~ g / d a y ) w i t h air s p a c e r w a s c o m p a r e d to o r a l a d m i n i s t r a t i o n o f f e n o t e r o l w i t h BDI in 12 p a t i e n t s w i t h b r o n c h i a l asthma. The crosso v e r c o m p a r i s o n for 8 w e e k s w a s p e r f o r m e d as following. S t u d y I : Six p a t i e n t s w e r e a d m i n i s t e r e d f e n o t e r o l t a b l e t s ( 7 . 5 mg/day) and B D I ( 4 5 0 ~g/day) d u r i n g 4 weeks. From the fifth week, patients were administered fenoterol MDI(0.6mg/ day) a n d B D I ( 4 5 0 ~ g / d a y ) d u r i n g 4 weeks. S t u d y II : Six p a t i e n t s w e r e a d m i n i s t e r e d fenot e r o l t a b l e t s ( 1 5 mg/day) a n d B D I ( 4 5 0 ~ g / d a y ) during 4 w e e k s . T h e r e s t of 4 w e e k s , the p a t i e n t s w e r e a d m i n i s t e r e d f e n o t e r o l M D I ( l . 2 m g / d a y ) and BDI(450pg/day). The changes of asthmatic sympt o m s and t r e a t m e n t s w e r e e v a l u a t e d b y s y m p t o m s s c o r e a n d t r e a t m e n t s score. T h e r e s u l t s obt a i n e d w e r e as follows. i) In s t u d y I, s y m p t o m s c o r e i m p r o v e d s l i g h t l y and t r e a t m e n b s c o r e a n d a s t h m a t i c s c o r e i m p r o v e d s i g n i f i c a n t l y a f t e r t r e a t m e n t o f f e n o t e r o l MDI. 2) A l s o in s t u d y If, s y m p t o m s c o r e i m p r o v e d s l i g h t l y , and t r e a t m e n t s c o r e s h o w e d no a p p a r e n t changes, but asthmatic score improved signific a n t l y a f t e r t r e a t m e n t of f e n o t e r e l MDI. From t h e s e r e s u l t s it w a s s u g g e s t e d t h a t t h e c o m b i n a t i o n t h e r a p y of f e n o t e r o l M D I w i t h BDI w a s m u c h m o r e e f f e c t i v e t h a n o r a l a d m i n i s t r a t i o n of f e n o t e r o l w i t h BDI. T h e F i r s t D e p a r t m e n t of I n t e r n a l M e d i c i n e , S c h o o l of M e d i c i n e , S h o w a U n i v e r s i t y , 1-5-8, H a t a n o d a i , S h i n a g a w a - k u , T o k y o 142, J A P A N

PP 12.34 TOLERABILITY AND PHARMACODYNAMIC EFFECTS OF INHALED IN HEALTHY SUBJECTS Ph.M~ller, D.Milovanovie, H.Howald, B.Franke, M.MacNab ~ FORMOTEROL

Formoterol (F), a new 82-agonist under clinical investigatlon, was administered as an aerosol in single doses of 6, 12, 24 and 48 meg to 12 healthy subjects in order to assess its tolerability and pharmacodynamlc effects during 8 hours as compared to placebo (P) and a 200 meg dose of salhutamol = albuterol (A). Tolerabillty of all treatments was good. Hand tremor was noticed by 2 subjects for 5 hours after the highest dose of F. Blood pressure was unaffected. Heart rate increased dose-dependently by up to 5 b.p.m, above P throughout 8 h after F only. Mean serum potassium levels were lowered within the normal range for up to 8 h in a dose dependent way (p < 0.02, profile analysis) after F, but were not different from P after A. No influence of either F or A was detectable on T-wave amplitude of the ECG which itself followed a distinct diurnal course. Cyclic AMP in plasma was increased from 30 min to 8 h after F by up to I0 nmol/l above P (p < 0.001, profile analysis), being the parameter most consistently influenced by ~2-stimulation. Some of the lung function parameters (FEV I, FEF 25-75%) tended to increase (n.s.) for up to 8 h after F, whereas after A the same parameters tended to increase only at 1 h after inhalation. It is concluded that inhaled F is well tolerated in healthy subjects at doses up to 48 meg and exerts potent and long-lasting pharmacodynamic effects for up to 8 hours after single doses. Efficacy and duration of effect of 24 and 48 meg F are more pronounced as compared to 200 meg of A. Pharmaceuticals Division, Clinical Pharmacology, CIBA-GEIGY Limited, 4002 Basle (Switzerland) and *CIBA-GEIGY Corporation, Summit, MJ 07901 and the Medical College of Pennsylvania, Philadelphia PA 19129 (USA).

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PP 12.37

TRANSDERMAL CONTROLLED DELIVERY OF THEOPHYLLINE

Withdrawn

S. C. Chattaraj, S. K. Das, S. K. Ghosal and B. K. Gupta A transderma] drug delivery (TDD) system with akin permeation enhancer was fabricated for the controlled drug delivery of theophyiline.

The TDD was composed of the copolymers

of acrylic and methacrylic acid esters. Various skin permeation

enhancers and their combination were incorporated

in the adhesive layer to make an enhancer adhesive multilaminate on the donor

phase

theophylJine

drug releasing surface.

composition

on the

was studied in

in the diffusion cells.

The effect of

transdermal

delivery

of

hairless mouse skin mounted

The observed theophy]line permeation

rates indicate that the enhancers delivered from the adhesive layer improved the permeation rate of theophylline. permeation

rate

of

theophylline

increased

as

The

increasing

the concentration of the enhancer in the adhesive layer. The advantage of using the multiple enhancer combinations was also observed.

The maximum rate of permeation and

the minimum concentration required were found to be dependent on the type of the enhancer used. that

the

skin

permeation

rate

of

The results indicate

theophylline

could

be

enhanced more than 200% with the skin permeation enhancer releasing TDD system.

Department of Pharmacy, Jadavpur University, Calcutta 700 032, India.

PP 12.38

PP 12.36 TWO NEW PROLONGED RELEASE THEOPHYLLINE PREPARATIONS PHARMACOKINETICS AND PHARMACODYNAMICS IN P A T I E N T S W I T H B R O N C H I A L ASTHMA. U.Belousov, A,Abazowa, L.Holodov, L.Bonderava, N.Koblasheva T h e pharmacokinetics a n d p h a r m a c o d y n a m i c s of t w o n e w S R - p r e p a r a t i o n s of t h e o p h y ! l i n e were investigated in 44 p a t i e n t s w i t h m i l d and moderately severe bronchial asthma. Comparisons were made with established preparations ( T h e o - D u r R, T h e o t a r d R, a n d DuraphyllinR). The pharmacokinetics of t h e n e w S R - p r e p a r a t i o n s in e q u i v a l e n t d o s e s w e r e s i m i l a r to the reference products. Relative bioavailaD i l i t y v a l u e s w e r e 95 % a n d 96 %, o b s e r v e d ~ l / Z v a l u e s w e r e 16 a n d 1 7 . 1 . hours and clearance was 4.1• and 4.5• ml/min. T h e in v i t r o r e l e a s e of o n e of t h e n e w SRproducts was biexponential whereas the diss o l u t i o n of t h e o t h e r t a b l e t w a s linear. Fherapeutic concentrations w e r e o b t a i n e d within 4-7 days. A linear correlation was found between the concentratlon of t h e o p h y l l i n e in b l o o d and %ne improvement in r e s p i r a t o r y function. No a d d i t i o n a l adverse drug effects were observed for the new preparations. Conclusion: T h e r e s u l t s of the t r i a l c o n f i r m the s u i t a b i l i t y of t h e t w o t h e o phylline SR-formuiations for'clinical use. -

Department of C l i n i c a l 2 nd M e d i c a l I n s t i t u t e , '117431 M o s c o w , U S S R

Pharmacology, Ostrovitianova

I,

DOUBLE-BLIND PLACEBO CONTROLLED CLINICAL TRIAL OF ALMITRINE IN PATIENT@ WITH CHRONI~ RESPIRATOR~ INSUFFICIENCY I. Bakran~B. Vrhovac r- B. Stangl, D. Tabory J and A. Ivi6evic The treatment of chronic respiratory insufficiency is often unsuccessful. The aim of this trial was to assessthe efficacy and tolerability of almitrine (Veetarion, Servier), a new respiratory stimulant, in patients with hypoxaemic form of chronic respiratory insufficiency caused by chronic bronchitis and emphysema. The trial was double-blind, placebo controlled with collective therapeutic comparison. 40.patients took part in the trial (23 in aimitrine group and 17 in placebo group), which lasted for 12 weeks. Almitrine was taken orraly, 50 mg b.i.d. A si~nificant increase (p ~ 0.01 ) in PaO. was achieved (control value 5~ .4t6.9 mmHg, 59.1t7.3 after 6 weeks, 5 9 ~ 9 . 3 after 12 weeks), in comparison to placebo (control value 56.6~ 7.1 mmHg, 56.9 t .3 after 6 weeks, 55.8111.6 after 12 weeks). There was significant (p~O.01) decrease of PaCO 2 in almitrine group after 12 weeks only. Lung function (FVC, FEVI, FEVI/FVC , R , TLC, RV, FRC) was not changed in either'group. Degree -o~'WdySpnea and 6-min walking test were significantly improved in almitrine group. Adverse reactions appeared in 6 out of 23 patients on almitrine (headache, urticaria, breathlessnes, diarrhea, chest pain, nausea and vomiting), causing drop out of 4 patients. In conclusion almitrine can be considered as a significant advantage in the treatment of patients with Chronic respiratory insufficiency. Isection Of Clin.Pharmac~l., Dept. of Medicine, Univ. Hospital Rebro, Zagreb; Institute for lung diseases,aGolnik; OInstitute for lung diseases, Sremska Kamenica; "Clinical Hospital for lung diseases, Jordanovac, Zagreb, Yugos&avia

A 283

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EVALUATION OF THE EFFICACY OF ASTEMIZOLs IN EXTRINSIC ASTHMATIC PATIENTS BY ALLERGEN PROVOCATIONTESTING, Abediae M, IGister6 A, De la Puente V~ :Pinto E, TorrentJ, BarbanojMJ and Jan~ F.

EFFECTS OF INHALED PLATELET-ACTIVATING FACTOR ON PLATELET aGGREGATION, PULMONARY FUNCTION AND CIRCULATION IN MAN

The development of new non-sedative antihislamine compounds such as astsmizole, has allowed a reappraisal of the role of histamine and selective Hl-rsceptor antagonists in allergic asthma. In a double blind, cross-overstudy leaving a wash-out periodof 2 months between each treatment and maintaining single-Blindplacebo intake throughout this period, singledaily oral doses of 30 mg and I0 eg astemizole against placebo wore administered,each during 2B days, to 12 patients suffering'extrinsicasthma.Albuterolwas allowed as commdicationwhen needed. On days O, 7 and 28 of each sxpsrimsnte]period the following assessmentswere carriedout: a> Basal FEV-I. b) Immediateallergeninduced airflow oPstructionthrough 20% fall in FEV-I (PD20)caused by inhalationof Dermatophaqoidespteronyssinus (lO, I00, lO00 and IO000 BU/m]h cl Degreeof inhibitionoi the wheal responsecaused by skin prick test with 0.01 mg/ml histamine and with toe same allergen concentration as before, d) 8-adrsnergic inhalationsand number of Pronchoapasm episodes were also recorded on a daily basis. Non parametric statistics were apphsd consiOering any p < 0.05 as significant.Basal FEV-I increasedon day 2Bth aftsr ~0 mg astemizole. PD2O could be calculated for aH petisntson days 0 and after placebo treatment (mean: 6000 8Ulmi) while with both astsmizole dosesthe highest allergen concentrationdid not provokePO20 in 50% patientson day 7 and in 80Z on day 28. Histaminewheals were reduced only after active treatment on days 7 and 28. The highest allergenconcentration wheal response was reduced at both recorded times after 30 mg astemizols,whereasthe IO mg dose only caused a reductionon day 2Sth. The rest of clinical evaluationswere also improved after astemizole intake and were dilferentfrom placebo, Althoughfurtherinvestigations will berequirsd to determine the clinical usefulness of astseizole therapy in the management of asthma, thoseresults indeedprovide a rational supportto the potential benefitsof the newer antihistamine~ in the treatmentof extrinsic asthmaticpatients, Olinical PharmacologyResearch and :Allergy Units, Hosp Sant Pau. Avda, S Antoni M Claret~ 167. O8025-Barcelona. Spain,

K. Moilanen, M.M. Nieminen, J . - E . Nyholm, T. Mets~-Ketel~ and H. Yapaatalo Department of Biomedical Sciences, University of Tampere and Tampere University Central Hospital, FINLAND Piatelet-activating factor (PAF) is a putative mediator of asthma and Inflammation as suggested by experimental models. Some of these effects seem to be mediated via activation of platelets. There are, however, only few studies on the effects of PAF in man. In the present work, we measured the effects of inhaled PAF (total dose 500 ug) on platelet aggregation, thromboxane synthesis, pulmonary function and circulation in seven healthy volunteers. PAF did not effect on ADP, adrenaline or PAF induced platelet aggregation in samples collected 20 or 60 min after the inhalation Aiso ~hromboxane (measured as TXB=> synthesis by plateiets during 30 min incubation of whole blood at 37~ remained uDaltered. However, PAF induced an acute bronchial obstruction, predominantly in smaller airways (ca 15% reduction in FEV.). Also bronchial hyperreactivity was seen in methacholine test performed in the next day. Systolic and diastolic blood pressure reduced (5-10% p(0.05) and heart rate accelerated (ca 15% p(O.01) transiently. Noradrenaline concentrations in plasma collected 20 min after PAF dosage were increased (ca 40% p<0.01) as compared to the levels prior to inhalation No adrenaline response was detected. We conclude that inhalation of moderate doses of PAF induces pulmonary and vascular effects without influencing a~gregatory responses or thromboxane synthesis in circulatinE platelets in man. Department of Biomedical Sciences, University of Tampere, P.O. Box 607. 33101Tampere, FINLAND

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THE EFFICACY OF THE NOVEL Ht ANTIHISTAMINE EBASTINE IN C O M P A R I S O N WITH REFERENCE DRUGS 0.54,. Bakke, X. Luria, J.P, Perez H u m a n volunteer studies with histamine-induced wheal test, supported by dose-finding trials in seasonal and perennial allergic rhinitis a n d chronic urticaria, have established the optimal therapeutic dose of the novel non-sedative H l antihistamine ebastine in adults as 10 mg o . d Established reference H1 antihistamines have been included in four randomized double blind clinical trials. Methods. Since antihistamine drugs are thought to act basically by the same mechanism in all of the conditions hitherto studied during the clinical development, a meta analysis has been carried out in order to assess the overall performance of ebastine in comparison with reference antihistamines at their respective recommended doses (terfenadine 60 mg bi.d., astemizol 10 mg o.d., chlorpheniramine S.R. 6 mg b.i.d., mequitazine 5 mg b.i.d.). The percentage of the patients reporting excellent or good symptom improvement was calculated together with the efficacy ratio of ebastine vs. reference d r u g and its confidence interval. Results. Excellent or good efficacy was reported by 195 out of the 364 patients treated with ebastine (53.6%) and by 188 out of 381 patients treated with reference drugs (49.3%). The efficacy ratio was 1.086 with a confidence interval of 0.948-1.224. According to the i n v e s t i g a t o r s ' assessments, excellent or good efficacy was obtained in 180 patients receiving ebastine (49.4%) and in 186 patients treated with reference antihistamines (48.8%). Conclusion. The meta analysis showed no difference between the overall efficacy observed in the patients treated with ebastine in comparison with the group receiving different reference antihistamines. Institute of Research, Laboratorios Almirall, Cardoner 68-74, 08024 Barcelona, Spain

T H E E F F E C T OF T H R O M B O X A N E SYNTHETASE INHIBITOR (OKY-046) A N D L E U K O T R I E N E C # / D # R E C E P T O R ANTAGONIST(ONO-1078) ON A I R W A Y H Y P E R R E S P O N S I V E N E S S ( A H R ) I N D U C E D B Y O Z O N E E X P O S U R E IN G U I N E A PIGS. F. K o k u b u , A. O k a z a w a , H. K o b a y a s h i , M. A d a c h i a n d T. T a k a h a s h i , M, M i s a w a * To evaluate the mechanism of AHR induced by o z o n e e x p o s u r e in g u i n e a p i g s , w e s t u d i e d t h e effect of thromboxane synthetase inhibitor (OK Y-046) and [ e u k o t r i e n e C#/D# r e c e p t o r a n t a g o nist (ONO-I078) on airway responsiveness (AR). &t 1 h o u r a f t e r o z o n e i n h a l a t i o n ( 2 . 9 p p m , 30min) AR to methacholine increased significantly, but t h e r e w a s n o c e l l u l a r c h a n g e in B A L f l u i d . Pretreatment with OKY-046(30mg/kg) or ONO-1078 (10mg/kg) i n h i b i t e d A H R a f t e r o z o n e e z p o s u r e significantly. These results suggest that both thromboxane and leukotrien$ p l a y an i m p o r t a n t r o l e in t h e d e v e l o p m e n t of AHR induced by ozone e x p o s u r e in g u i n e a p i g s . The First Department of Internal Medicine, School of Medicine~ Showa University, 1-5-8, Hatanodai, Shinagawa-ku, T o k y o 142, J A P A N * D e p a r t m e n t of A p p l i e d P h a r m a c o l o g y , School of Medicine, Hoshi University, Tokyo, JAPAN

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DEPRE~ION OF PERIPHERAL NEUTROPHIL CHEMOTAXIS BY E~OREANDPROTECTIONBY ERCK]STEINE A. Ciaeeia, G.B. Fregnan,A. Papi and A. Poma There are no doubts that cigarette smoke has deleterious effects on a number of physiological'functions. Among them, the chemotactic responsivenessof leukocytes, namely the polymorphonuelearcells (PMN), isolated from peripheral blood was shown to be depressed in smokers (Noble R,C. and Penny B,B., 1975), A recent study (BridgesR.B., 1985) has indicatedthat the smoke is directly responsible for it and thal.some thiole may have a protectiveaction in vitro on this neutrophil function. The aim of the present study was to investigateif erdosteioe (a novel mucoregulator endowed ~ith free radical scavenging properties) and some of its possible metabolites might preserve or restore the normal neu%rophil chemotactic response altered by cigarette smoke in vitro and in viuo, For the purpose, in the in vitro experiment the PMN from B healthy nonsmeking untreated volunteers were preincubateaat 37% with the drugs at increasing concentrations before exposure to smoke. It has been observed tha~.erdosteine as such was ineffectivewhile, after hydrolytic or enzymatic liberation of its SH groups, it protected the PflN.Its synthetic metaboliteswere also active (minimal effective concentrations ranging from 0.1 to I mMl. The in rive experiN~ent was performed in 8 healthy heavy smokers with a depressed PMN chemota• according to a doubie blir,d crossover design. The volunteers ~,ere orally treated with erdos~eine 300 mg TID for B weeks or with placebo and neutrophil chemotactic responsiveness tested both before any treatment and t'~e hours after the last morning dose, with subjects smoking 2 cigarettes during the leer 30 minutes preceding the blood samplings.At leas% 30 days were allowed to elapse betweendifferent treatments. In these conditions, the PMN chemotaxis was restored almost to its normal responsivenessby erdosteioe treatment. Furthermore, a double blind preliminary study in 40 smoking patients affected by chronic obstructive iung disease (subdivided in two groups of 5 each) also indicated %ha% erdos%eine (300 mg TIB for s weeks), but not placebo, was able %o restore the neutrophil ~unstion. These findings, if confirmed in a larger populationof patients, might have some relevance for %he prever~tion os infective exacerbationsin chronic bronchitics, since neu%rophilshave a primary role in host defense against acute infections and defective thee,eta• might result in increased host susceptibility to recurrentbacterial infection(Miller M.E. et al,, 1971, Ward P. Ig7B; Boxer L,A. et a1., 1974). Chair of Respiratory Diseases, University of Ferrara, Italy; ResearchCenter EdmondPharma, Milano, l~aiy: Refarmed, Zurich, Switzerland.

T H E E F F E C T OF A S P E C I F I C ~ N T A G O N I S T OF T H R O M B O XANE A2(AA-2414) ON AIRWAY HYPERRESPONSIVENESS INDUCED BY OZONE EXPOSURE IN B E A G L E S T. I m a i , M. A d a c h i A. O k a z a w a , K. I d a i r a , T. S u g a n u m a a n d T. T a k a h a s h i In o r d e r to e v a l u a t e the inhibitory effect of AA-2414, a specific TXA 2 antagonist on airway hyperresponsiveness induced by ozone exposure in f i v e b e a g l e s , t h e f o l l o w i n g study was carried out. Airway responsiveness to methacholine was measured by modified Astograph (7 Hz o s c i l l a t i o n method) before and after ozone exposure, and T x B 2 in p l a s m a a n d in B A L F , a n d d i f f e r e n t i a l cell counts in BALF were measured before and after ozone exposure. Ozone exposure was c a r r i e d o u t f o r 2 h r s a t an o z o n e l e v e l o f 3.0 ppm. Ther~ was a significant increase in a i r way responsiveness to methacholine after ozone exposure in t h e f i v e b e a g l e s (p<0.05), and a prior treatment with a specific antagonist of TY~2, ~-2414 (30mg/kg by oral administration), significantly inhibited t h e i n c r e a s e of a i r w a y responsiveness to m e t h a c h o l i n e induced by ozone exposure (p<0.05). T h e r e s u l t s s u g g e s t t h a t T x p l a y s an i m p o r t a n t r o l e in t h e d e v e l o p m e n t of a i r w a y h y p e r r e s p o n siveness induced by ozone exposure in b e a g l e s . The First Department of Internal Medicine, S c h o o l of M e d i c i n e , Showa University, 1-5-8, Hatanodai, Shinagawa-ku, T o k y o 142, J A P A N

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THE EFFECT OF KC-404, A NEW ANTAGONIST OF ON ALLERGEN-INDUCED LATE BRONCHOCONSTRICTION Y. O k a d a , M. A d a c h i , H. H o s h i n o , H. K o b a y a s h i , S. K o n n o , A. O k a z a w a , T. S u g a n u m a , S. M a r u y a m a a n d T. T a k a h a s h i Allergen-induced bronchoconstrictive responses were examined in g u i n e a p i g m o d e l , a c t i v i t y sensitized by inhalation of a e r o s o l i z e d ovalbumin (OA), w h i c h s h o w e d r e p r o d u c i b l e late bronchial responses(LBR). OA-challenge was performed u n d e r c o v e r of m e p y r a m i n e t h r o u g h t h e i n h a l e d r o u t e in s p o t a n e o u s breathing without anesthesia. The respiratory resistance(Rrs) was measured by the oscillation m e t h o d f o r as l o n g as 96 h r s a f t e r O A c h a l l e n g e . Twenty-two o f 22 g u i n e a p i g s d i s p l a y e d immediate bronchial responses(IBR), f o l l o w e d b y 2 or 3 p h a s e L B R t h a t p e a k at 6 - 8 h r s a n d 24 h r s a f t e r OA. Examination of bronchoalveolar lavage fluid (BALF) r e v e a l e d a significant increase in n e u t r o p h i l s at 1 h (p<0.01) a n d e o s i n o p h i l s at 7 h r s a n d 96 h r s ( e a c h p < 0 . 0 1 ) a f t e r O A c h a l l e n g e . OA-challenge induced airway hyperresponsiveness to h i s t a m i n e (p<0.01) at 96 h r s t h a t w a s a s s o c i ated with a significant increase in e o s i n o p h i l s (p<0.01) in B A L F c o m p a r e d w i t h at 7 h r s l a v a g e s . The increases o f R r s in L B R w e r e i n h i b i t e d almost completely by the pretreatment of K C - 4 0 4 , w h i c h is r e p o r t e d to have the antagonistic a c t i o n a g a i n s t L T C 4 / D 4. The First Department of I n t e r n a l M e d i c i n e , School of Medicine, Showa University, 1-5-8, Hatanodai, Shinagawa-ku, T o k y o 142, J A P A N

ANTIBRONCHOSPASTIC AND ANTIALLERGIC ACTIVITIES OF LEVODROPROPIZINE IN ANIMALS AND ASTHMATIC/ALLERGIC HYPERREACTIVEPATIENTS Lavezzo A., Bossl R. Q, Melillo G., Borsa M. Interesting' antibronchospastic and antiallergic properties of levodroproplzine, a new effective antitussive drug without CNS Side effects, were recently detected in animals. Levodropropizine was very active against capsaicin-(ID 27 (20-36 mg/kg p.o.) and histamine-(ID 80 50 ' 50 (39-164) mg/kg, p.o.) but not acetylcholine aerosol-induced bronchospasm in conscious guinea pigs and on bronchocenstrietions induced by BK, capsaicin, histamine and 5HT (ID : g.8 (7.5-12), 7.7 (6.5-9.2), 2.3 50 (2.1-2.5) and 2.1 (1.9-2.4) mg/kg, i.v., respectively) in the amaesth.etized gulnea-pig by the Konzett and Rgssler method. In addition, levodroproplzine was active against compound k8/80-induced lethallty

(ID50 mg/kg: 2.4 (2.0-2.7) p.o.; 0.6 (0.3-1.1) i.p.) and passive cutaneous anaphylactic reaction (Ig mg/kg: 12 (g-11), p.o.; 8.2 50 { 5 . g - l l ) , i.p.) in rats. To investZgate the antibronchospasm and antiallergic activlties of levodropropizine in man, 7 asthmatic/allergic hyp'erreactive patients with history, prick tests and Rast positive for the most common inhaled a11ergens were selected. All patients responded in 2 preliminary challenge tests (ultrasonic mlst water) with decreases in FEVI not lese than 20%. Bronchodilators and theophylllnic drugs were stopped at least 24 h before treatment. Levodropropizine (60 mg, p.o., t . i . d . ) was administered for 8 days and than the fog test was performed again. A11 patients responded positively to levodropropizine treatment with the resistance to hyperreactiee bronchospasm prolonged from 100 to 500% of the basal time. Levodropropizine, in addition to local antltussive effects, showed antibronchocenstrictor and antiallergic activities that may be related to a partial block of "irritant receptors" and/or "Axon reflexesII mediated from C-fiber. Research ~ Development Laboratories, Domp~ Farmaceuticl S.p.A., Milan, Italy and ~ of Respiratory Diseases, University of Milan, Milan, Italy

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INHIBITORYEFFECT OF AZELASTINE ON ALLERGEN-INDUCED BRONCNOCONSTRICTION

ACTION OF AMILORIDE ON AIRWAY SECRETIONS AND LUNG DEFENSE MECHANISMS IN DOGS. M. Kine. E.M. App. O. Ramirez. J.G.Zayas. Amiloride, a blocker of transepithelial sodium transport, has been proposed as a potential therapeutic means of increasing airway water content. Administration of amiloride by aerosol to patients wffh cystic fibrosis has been shown to acutely increase mucociliary and cough clearance (Am Rev Resp Dis 1988;137:A303). However, experiments using isolated frog palate (Am Rev Rasp Dis 1984;129:816) showed that although amiloride stimulated mucus discharge, it inhibited mucociliary clearance. The latter experiments, as well as those in patients (N Engl J 1981; 305:1489) and in animals (J Appl Physiol 1980; 48:169 ), showed that amiloride reduces transepithelial potential difference (PD), consistent with its effect on ion transport. We wished to address the controversies regarding the effect of amiloride on secretion and lung defense using an in rive canine model. Healthy beagle dogs were anesthetized with pentobarbital and intubated. Normal saline aerosol, delivered by a Pari jet nebulizer, was provided, to maintain humidity and to serve as a control. Freshly prepared Amiloride (10-3 M in saline) was administered for 10 minutes via the same nebulizer. PD measurements were made using an agar bridge technique. Tracheal mucus velocity (TMV) was determined by direct visualization of charcoal particle movement, Mucus was collected by means of a cytology brush. Rheological analysis included magnetic rheomatry ('viscosity + elasticity", G*; and viscosity/elasticity ratio, tan 6) and spinnability by fiiancemeter. Six dogs were studied; each dog was administered amiloride on two occasions. Control experiments, using only saline, were performed several times in each animal. Measurementswere made prior to Ami]oride administration, and during the subsequent 1.5 hours. Amiloride caused an immediate fall in tracheal PD in each experiment, followed by a partial return towards control by 0.5-1 hour. The immediate change in TMV was inconsistent, but it was invariably reduced from control by 1 hour. The mucus viscoelasticity (G*) was significantly reduced at 0.5 end 1 hr following Amiloride, and the quantity collected was increased. Filance increased with Amiloride and the % solids content decreased. These latter factors are all consistent with increased mucociliary clearabillty (MCI), and conflict with the observation of decreased in vivoTMV, suggesting that either cilia beat frequency (CBF) was decreased or the interaction between the mucus and the cilia was disturbed. Since CBF was not decreased in other studies, the latter situation is more likely. This would be consistent with an increase in the depth of periciliary fluid, which would be non-beneficial in the normal case, but which could be of value ]f the periciliarylayer was inadequate. Time course PD (mV) log G* TMV (mm/min) MCI pre-AmiIoride -13.1 -+ 1.3 2.6 • 0.09 11.9 --. 1.6 0.81 • 0.02 < 0.5 hr post Am -5.8 • 0.7 2.3 +_0.09 9.8 • 2.5 0.90 • 0.02 ~ 1 hr post Am -8.3 • 0.4 2.2 • 0.06 4.2 • 1.7 0.91 • 0.03 Data are shown as mean • SE. [Supported by Canadian Cystic Fibrosis Foundation] *Mucology Group, Dept. of Medicine, University of Alberta, Edmonton, Canada.

P.Rafferty, D.Nq, G.Phillips, R.Aurich, S.T.Holqate We have examined the effect of azelastine on allergen induced bronchoconstriction in 11 atopic asthmatics in a double blind, randomised study. Four hours after oral azelastine hydrochloride 8.8 mg or placebo intake subjects inhaled a dose of allergen previously shown to produce a 25 % f a l l in FEV~. Plasma h i s t a m i n e concent r a t i o n s and FEV, were measured o v e r 8 hours. F o l l o w i n g placebo a l l s u b j e c t s developed a r a p i d b r o n c h o c o n s t r i c tion during the first 30 minutes (mean maximum f a l l in FEV, 22.8 • 3.4 %), f i v e s u b j e c t s a l s o developed a l a t e bronchoconstrictor response between 2 to 8 hours post c h a l l e n g e (mean maximum f a l l in FEV~ 23.9 • 6.3 %). Azelastine d i d not reduce the maximum b r o n c h o c o n s t r i c t i o n seen d u r i n g t h e e a r l y r e a c t i o n (mean maximum f a l l 21.2 • 4.4 ~) but a n a l y s i s o f the area under the FEVL response t i m e - c o u r s e d u r i n g the p e r i o d 0 to 2 hours r e v e a l e d a 32.5 % r e d u c t i o n in b r o n c b o c o n s t r i c t i o n (p < 0.05) (all subjects). Azelastine had a marked inhibitory effect on the l a t e r e a c t i o n r e d u c i n g the maximum f a l l in FEV, t o 9.6 • 3.9 % from the post saline b a s e l i n e v a l u e and reduced the o v e r a l l bronchoc o n s t r i c t o r response observed in the p e r i o d from 2 to 8 hours by 70.2 % (p < 0 . 0 5 ) . A z e l a s t i n e had no s i g n i f i c a n t e f f e c t on plasma h i s t a m i n e c o n c e n t r a t i o n s . We conclude that azelastine significantly i n h i b i t s the l a t e r e a c t i o n t o i n h a l e d a l l e r g e n and t h i s may r e f l e c t its known i n h i b i t o r y action against leukocyte activation and m e d i a t o r responses. Medicine England

i,

Southampton General H o s p i t a l ,

Southampton,

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INHIBITION OF LEUKOTRIENE RELEASE FROM NEUTROPHILS IN ASTHMATIC PATIENTS BY AZELASTINE HYDROCHLORIDE Y.Matsumoto, K.Shindo, M.Matsumura, and T.0kubo The inhibitory effect of anti-asthmatic drug, azelastine hydrochloride, on leukotriene (LT) release from human neutrophils was investigated. Human neutrophils of normal and asthmatic subjects, isolated by Percoll density gradient centrifugation, were preincubated with or without various concentrations of azelastine hydrochloride (lxlO -7 to IxlO "4 M) for 15 to 360 min, and stimulated with calcium ionophore A23187 (l~M) for 15 min. After centrifugation, the supernatant were extracted on SEP-PAK CI~ cartridge column for separation by high pressure liquid chromatography. The L T ~ and L T ~ were quantitatsd by radioimmunoassay. The LTs released from human neutrophils stimulated with A23187 in asthmatic and normal subjects were as follows : 6.6• (mean• n=14) and 3.ieI.6 ng/lO ~ cells (n=lO), respectively for LTB, ; 3.2m2.0 (n=22) and 1.9~0.8 ng/lO~cells (n=17), respectively for LTC~. The neutrophils of asthmatic subjects showed significantly higher response of LTB4(p
TIME OOURSE OF }~9ONCHO~PASMOLYTIC EFFECTS A~'rE.~ INJECTION OF DIFFSI~[s WATER-SOLUBLE GLUfXX]gRTIOOIDS H.W. MSllmann, J. Barth, H. Derendorf , G. H0chhaus The pharmacokinetics and pharmacodynamic effects of intravenously administered water-soluble glucocorticosteroids (80 mg methylprednisolone (MP), 80 mg triamcinolone acetonide (TCA) and 100 mg prednisolone (PRED)) were investigated in 80 patients with severe airway obstruction. Parallel to the plasma concentration time profils the total airway resistance (Rt) and intrathoracal gas volume (IGV) were recorded bodyplethysmographically, additionally lung volumes and flow volumecurves were measured in short intervalls by a pneumotachograph. In about 2/3 of the patients inspiratory capacity (VCIN) and forced exspiratory capacity (FVC) increased significantly (more than 50 % of the initial values). Rt started to decrease within the first 15 minutes after steroid application, the reduction was mainly due to decreasing exspiratory airway resistances and went parallel to a normalisation of flow-pressure curves. Within the first 30 minutes after glucocorticoid injection FVC increased mainly due to prolonged exspiration whereas FVC increase after I h was attributed to enhanced exspiratory flow rates. Methylprednisolone is shown to have a stronger efficiency than prednisplone and triamcinolone acetonide. Medizinische Klinik Bergmannsheil, Ruhr-Universitit, 4630 Bochum, FRG College of Pharmacy, University of Florida, Gainesville, F1 32610, U.S.~

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Medizinische Klinik Bergmannsheil, Ruhr-Universitit, 4630 Bochum, FRG College of Pharmacy, University of Florida, Gainesville, F1 32610, U.S.A. Institut fur Pharmazeutische Chemie, Westf. Wilhelmsuniversitit, 4400 M~nster, FRG

THE E F F E C T I V E N E S S OF A Z E L A S T I N E H Y D R O C H L O R I D E , A N E W A N T I A L L E R G I C A G E N T IN L O N G T E R M A D M I N I S T R A T I O N ON THE P A T I E N T S W I T H B R O N C H I A L A S T H M A Y~ K a w a k a m i , M. A d a c h i , F. K o k u b u , S. M i t a and T. T a k a h a s h i The e f f e c t i v e n e s s of A z e l a s t i n e h y d r o c h l o r i d e which inhibits chemical mediators release from m a s t c e l l s and n e w t r o p h i l s and is also an ant a g o n i s t to h i s t a m i n e and LTC4, D4, on the pat i e n t s w i t h e x t r i n s i c a s t h m a w a s studied. F i f t y five p a t i e n t s w i t h b r o n c h i a l a s t h m a aged 16 to 7 2 ( m e a n age 40.2 y.o.), 19 m a l e s and 36 f e m a l e s w e r e e n r o l l e d in this study. The patients were administered Azelastine hydrochloride 4 m g in a d a y d u r i n g 12 w e e k s . The e f f e c t i v e n e s s of A z e l a s t i n e h y d r o c h l o r i d e w a s e v a l u a t e d b y the c h a n g e s of s y m p t o m s c o r e and t r e a t m e n t score. A i r w a y h y p e r r e a c t i v i t y to m e t h a c h o l i n e b e f o r e and a f t e r a d m i n i s t r a t i o n of Azelastine hydrochloride was also studied. The r e s u l t s o b t a i n e d w e r e as f o l l o w s , 9.1% s h o w e d m a r k e d l y i m p r o v e m e n t , 25% s h o w e d imp r o v e m e n t , 23.6% s h o w e d s l i g h t l y i m p r o v e m e n t , 18.2% s h o w e d no c h a n g e in t h e i r s y m p t o m s and 3.6% s h e w e d e x a c e r b a t i o n . F B V I . 0 , FEVI. 0 %, P F R a n d V25 s h o w e d a s i g n i f i c a n t i n c r e a s e a f t e r a d m i n i s t r a t i o n of A z e l a s t i n e h y d r o c h l o r i d e . F r o m t h e s e r e s u l t s , it is s u g g e s t e d that A z e l a s t i n e h y d r o c h l o r i d e is u s e f u l for the m a n a g e m e n t of b r o n c h i a l asthma. The F i r s t D e p a r t m e n t of I n t e r n a l M e d i c i n e , S c h o o l of M e d i c i n e , S h o w a U n i v e r s i t y , 1-5-8, H a t a n o d a i , S h i n a g a w a - k u , T o k y o 142, J A P A N

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RATIONAL DRUG DEVELOPMENT OF IMMUNOMODULATORS C~W.Hendrix~ B.G.Petty, D.S.Kornhauser, P.S.Lietman The therapeutic promise of biologic response modifiers cannot be fulfilled until one rigorously answers the question "how much and how often?" to avoid premature misadventures into efficacy trials. Our studies have focused on the time course of the biologic effect of a-interferon (IFN) and ampligen to characterize the dose-responses, dosing intervals, drug interactions and the spectra of immunomodulation. To define the kinetics of ~-IFN's biologic effects in man we followed 2'-5' oligoadenylate synthetase (25AS) and cellular resistance to vesicular stomatitis virus (VSV) challenge. A rise of 25AS activity and VSV resistance after ~-IFN dosing outlasted the presence of a-IFN by four days~ These two markers correlated well with each other in duration and magnitude and were not associated temporally with IFN's side effects. The relation of IFN dose to 25AS activity was log-linear. Given concurrently with ~-IFN (18 mu i.m.), neither prednisone, aspirin nor acetaminophen altered IFN's biologic response. These same interactions at lower do~e~ of ~-~FN are under study. Ampligen, a double-stran~e4mismateheaR]~A, induces interferon (~, B and 7) in vitro and protects animals from viral infections. We tried to define the spectrum and duration of ampligen's immunologic effects in man. In a blinded crossover study with a placebo control, healthy volunteers received a single 200 mg i.v. dose (similar to that used twice weekly in a multicenter efficacy trial). Neopterin, a product of 7-1FN-activated macrophages, served as a marker of 7-IFN's biologic effect. We saw no difference between ampligen and placebo effects on ~- or 7-IFN, 25AS, neopterin, T cell subsets, or natural killer cell and lymphocyte function. This study continues at a 600 mg dose. These early studies are critical to the rational design of clinical efficacy trials and serve as models for the development of biologic response modifiers. Johns Hopkins University. 600 N. Wolfe St., Osler 527, Baltimore, MD 21205, U.S.A.

NC0-650 INHIBITS AIRWAY HYPERRESPONSIVENESS C A U S E D BY O A C H A L L E N G E IN G U I N E A PIGS. SPECIAL REFERENCE W I T H THE I N H I B I T O R Y E F F E C T OF N C 0 - 6 5 0 ON L A T E BRONCHIAL RESPONSE(LBR) S. Konno, H. H e s h i n o , H. K o b a y a s h i , A. O k a z a w a , Y. Okada, T. S u g a n u m a , S. M a r u y a m a , M. A d a c h i and T. T a k a h a s h i Allergen-induced broncheconstrictive responses w e r e e x a m i n e d in g u i n e a p i g model, a c t i v e l y s e n s i t i z e d by i n h a l a t i o n of a e r o s o l i z e d o v a l b u m i n ( O A ) , w h i c h s h o w e d r e p r o d u c i b l e late b r o n c h i al r e s p o n s e s ( L B R ) . O A - c h a l l e n g e w a s p e r f o r m e d u n d e r c o v e r of m e p y r a m i n e t h r o u g h the i n h a l e d r o u t e in s p o n t a n e o u s breathing without anesthesia. The r e s p i r a t o r y r e s i s t a n c e ( R r s ) w a s m e a s u r e d by the o s c i l l a t i o n m e t h o d for as long as 96 hrs a f t e r O A c h a l l e n g e . T w e n t y - t w o of 22 g u i n e a p i g s d i s p l a y e d i m m e d i a t e b r o n c h i a l r e s p o n s e s ( I B R ) , f o l l o w e d b y 2 or 3 p h a s e L B R t h a t p e a k a t 6-8 h r s and 24 h r s a f t e r OA challenge. OA-challenge induced airway h y p e r r e s p o n s i v e n e s s to h i s t a m i n e (p<0.01) at 96 hrs. N C O - 6 5 0 ( a n e w a n t i - a l l e r g i c agent, 1 0 0 m g / kg) p r e t r e a t e d b e f o r e c h a l l e n g e b l o c k e d t h e 6-8 hrs and 24 hrs LBR. W h e n a d m i n i s t e r e d 1 hr a f t e r c h a l l e n g e , N C O - 6 5 0 a l s o i n h i b i t e d the 6-8 hrs and 24 hrs LBR, a s s o c i a t e d w i t h the i n h i b i t o r y e f f e c t of O A - i n d u c e d a i r w a y h y p e r r e s p o n s i v e n e s s to h i s t a m i n e . Our findings correlate w i t h the c l i n i c a l e f f e c t s of N C 0 - 6 5 0 , s u g g e s t i n g the g u i n e a - p i g m o d e l m a y be u s e f u l for i n v e s t i g a t i n g the m e c h a n i s m o f a c t i o n of a n t i - a s t h m a t i c drugs. The First D e p a r t m e n t of I n t e r n a l M e d i c i n e , S c h o o l of M e d i c i n e , S h o w a U n i v e r s i t y , 1-5-8, H a t a n o d a i , S h i n a g a w a - k u , T o k y o 142, J A P A N

TRANSFER OF DIFFERENT WATER-SOLUBLE THROU(~{ THE ALVEOLAR MEMBRANE

GLUCOODRTICOSTEROIDS

J. Barth, G. Hochhaus, H.W. MSllmann, P. Rohdewald As yet there is only little knowledge about the penetration of systemically applicated glucocorticoids through human lung tissue and resulting intrapulmonary concentrations in rive. Using bronchoalveolar lavage (BAL) we tried to gain more informations about the local lung concentrations of triamcinolone acetonide (TCA), dexamethasone (DEX), methylprednisolone (MP) and predniselene (PRED) given intravenously as water-soluble hemisuccinate resp. phosphate esters. Quantitative determinations of the steroids were performed by HPLC or RIA method; the urea concentration in blood and BAL fluid served as reference standard comparing blood and lung steroid values. On the basis of BAL procedures done in 40 patients we found different transfer properties of the applied compounds: ratios of lung to blood concentration were 0.52 for TCA, 0.83 for MP, 1.08 for DEX and 1.38 for PRED. These ratios will be set in comparison to results of additionally done investigations of the inverse transfer properties and pharmacokinetics of TCA and MP given as spray bolus into the bronchial tract during bronchoscopy.

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A COMPARISON OF THE PROTECTIVE E F F E C T OF P R O CATEROL AEROSOL AND PROCATEROL TABLETS ON BRONCHOCONSTRICTION INDUCED BY METHACHOLINE OR ALLERGEN INHALATION S. M i t a , M. A d a c h i , H. K o b a y a s h i , F. K o k u b u , Y. O k a d a , S. M a r u y a m a , H. S a t o , H. N i s h i k a t a a n d T. T a k a h a s h i Ten patients with bronchial asthma were studied to compare the inhibitory effect of the procaterol aerosol(PA) and procaterol tablets(PT) on bronchial responses to methacholine(ME) inhalation. The clinical value of the two dosage formulations was determined by measurements of FEVl, MMEF, PEFR, ?50, ?25, Rrs, and airway reactivity t o M E in t e r m s o f t h e c h a n g e in t h r e shold concentration. These pulmonary function tests and the ME inhalation test were performed at 1-week intervals, before treatment, 1 hr after oral administration of PT(50~g), a n d 15 min after inhalation of PA(20~g) in t w o p u f f s . The results revealed that PA was more potent t h a n P T in t h e i n h i b i t i o n of b r o n c h o c o n s t r i c t i o n d u e to M E i n h a l a t i o n . Inhibitory effect of PA and PT on bronchoconstriction d u e to allergen inhalation in a d o u b l e b l i n d s t u d y w i l l be d i s c u s s e d . The First Department of I n t e r n a l M e d i c i n e , School of Medicine, Showa University, 1-5-8, Hatanodai, Shinagawa-ku, T o k y o 142, J A P A N

HUMAN INTERLEUKIN-2 ATTENUATES LIVE RECOMBINANT VACCINIA VIRUS INFECTION IN PRIMATES. C. Flexner*, B. Moss, W. T. London, and B. R. Murphy Vector-directed lymphokine expression represents a novel approach to the attenuation of infections caused by live recombinant microbes which might be used as vaccines or gene transfer vectors. Expression of interleukin-2 (IL-2) by live recombinant vaccinia virus has been shown to significantly attenuate virulence in rodent species without diminishing the immunogenicity of the virus. We examined skin lesion formation and immunogenicity of vaccinia/IL-2 recombinants in three species of primates. Wild type and a control recombinant vaccinia virus produced large (>5000 square mm) skin ulcers in patas monkeys after intradermal inoculation of 1 m i l l i o n plaque-forming-units of virus, but the same inoculum of a recombinant expressing human IL-2 produced no ulceration. IL-2 expression was associated with a 15-fold reduction in the area of induration as well. The production of antibodies to influenza A virus hemagglutinin expressed by recombinant vaccinia viruses was unaffected by IL-2 expression in rhesus and squirrel monkeys. Antivaccinia antibody titers were similarly unaffected. These studies suggest that IL-2 expression can greatly reduce the skin lesions formed by live infectious vaccinia virus in primates, indicating significant attenuation. Such reduced virus virulence does not occur at the expense of immunogenicity, suggesting that such vectors would be safe and efficacious vaccines. National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA. *Current Address: Division of Clinical Pharmacology, Departments of Medicine and Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, MD'21205 USA.

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IMMUNOSUPPRESSIVE EFFECTS OF C Y C L O S P O R I N - A IN 40 PATIENTS WAITING FOR C A R D I A C TRANSPLANT. E. Albengres, P. R i a n t , A. G a r d i e r , D. Loisance, C. g e n v e n u t i , 3. Barr4~ 3.P. Tillement and 3.P. C a c h e r a . M o d i f i c a t i o n s i n d u c e d b y c y c l o s p o r i n - A (CSA) in l y m p h o c y t e f u n c t i o n and e n u m e r a t i o n w e r e studied in #0-end s t a g e h e a r t disease p a t i e n t s (P) w a i t i n g for h e a r t t r a n s p l a n t a n d p e r f u s e d with CSA alone 1, 2 or # m g / k g for 24 hours (h). L y m p h o c y t e subset t y p i n g , e n u m e r a t i o n and p r o l i f e r a t i o n ( l y m p h o c y t e t r a n s f o r m a t i o n index = LT1) w e r e m e a s u r e d b e f o r e t r e a t m e n t (TO) a t the end of the infusion (T2t;h) a t Tggh and a t T72h (-Txh). A c c o r d i n g to p r e l i m i n a r y s t a t i s t i c a l analysis, the d i f f e r e n t doses a d m i n i s t e r e d showed no s i g n i f i c a n t d i f f e r e n c e in t h e i r e f f e c t s on LTI no m a t t e r w h a t the Txh (p> 0.05). Thus all p a t i e n t s w e r e included in the s a m e p o p u l a t i o n for f u r t h e r analysis. It has c o m p a r e d the m e a n l y m p h o c y t e subsets a t Txh on the one hand and t h e LTI r a t i o s T0/Txh on t h e o t h e r hand using a two f a c t o r principal c o m p o n e n t a n a l y s i s ( p a t i e n t / p e r i o d ) and a S t u d e n t ' s T t e s t using the residual value. 1) CSA did not induce a n y s i g n i f i c a n t c h a n g e in cell subset e n u m e r a t i o n a t Txh. 2) A m a j o r d e c r e a s e in t h e LTI was n o t e d for all p a t i e n t s and o c c u r r e d e i t h e r a t T24h (31p) or a t T#gh (9P). The LTI r e t u r n e d to its initial level or rose in g r o u p 1 (30P) w h e r e a s it r e m a i n e d low in g r o u p 2 (10P). The s t a t i s t i c a l a n a l y s i s showed t h a t the interindividuai v a r i a b i l i t y was found no signif i c a n t in the t w o groups. 3) In g r o u p 1, T0/Txh LTI ratios s i g n i f i c a n t l y d i f f e r e d when in g r o u p 2 t h e r e was no s i g n i f i c a n t d i f f e r e n c e as to the period c o m p o n e n t . The i n h i b i t i o n of t h e l y m p h o c y t e p r o l i f e r a t i v e r e s p o n s e w a s shown to be e a r l y and p o t e n t which s u g g e s t s t h a t CSA could be given with b e n e f i t w i t h o u t d e l a y as soon as h e a r t t r a n s p l a n t has been p e r f o r m e d . The d e c r e a s e in t h e p r o l i f e r a t i v e response being quickly r e v e r s i b l e in g r o u p i a f t e r CSA w a s r e m o v e d , one m i g h t d r a w a t t e n t i o n to its e f f e c t d u r a t i o n when it is used alone a n d / o r a t l o w d o s e s as it is in a u t o i m m u n e disease treatment. As g r o u p 2 did not r e c o v e r a t T72h it is obvious t h a t CSA d i v e r s e l y a l t e r e d the p a t i e n t s ' i m m u n e response. Laboratoire Hospitalo-Universitaire de Pharmacologie, HSpital l n t e r c o m m u n a l , 40 a v e n u e de Verdun, F-94010 CRETEIL CEDEX.

CANCER TREATMENT WITH IMMUNOTHERAPY USING INTERLEUKINE-2 AND LYMPHOKINE-ACTIVATED-KILLER CELLS J. Kraus, D. van der Harst, P. Vermeij, S. Osanto, A. Brand. Adoptive cellular immunotherapy using imterlet~-2 (rilL-2) and Lympl~klne /~tlvated Killer ceils (LAK-cells) is a new therapeutic approach for cancer patients. The production of LAK-cells however is cumbersome and expensive. After a 120 hrs-priming course of rIL-2, four leukaphereses are carried out and mononuclear cells are incubated in a culture medium, containing 1000 U of rIL-2 in the presence of heparin. After 4-days of incubation the LAK-cells are harvested and administrated to the patient together with rIL-2. This treatment is repeated once. For these two cycles 150 L of culture medium are needed. Since the use of allogeneic serum is associated with serum transmissable diseases, many centres use the serum free culture medium AIM V, which is rather expensive. We investigated whether a standard culture medium like RPMI can be used instead of AIM V. We tested LAK-eell activity against four different target cell populations in nine different media: AIM V (100%), a mixture of RPMI and AIM V (4:1) with autologous serum (0, 0.25, 0.35, 0.5, 0.75, 1 and 2%). vs. our in vitro standard (RPMI 90% + pooled human serum 10%), No difference was found in viable recovery and cytotoxicity for cells cultured in AIM V or RPMI mixtures with a serum concentration >0.35 %. For the therapy of one patient nearly 100 3-1iter culture bags are needed. We compared the culture bags (Fenwall or Dupont) with co~ercially available total parenteral nutrition EVA-bags (ethylvinylacetate). No significant difference was detected. The modification of the culture medium and cell culture bag lowered the cost per pat%ent from US.$ 6803 to US $ 2048. After the treatment of five patients with metastatic renal cell carcinoma were treated and we observed with this new irmnunotherapy one complete remission, two partial remissions, one patient with stable disease and one patient off study due to the neurotoxic complications. Depts. of Clinical Pharmacy, Immunohaematology and Bloodbank, Clinical Oncology. University Hospital, PO Box 9600, NL-2300 RC Leiden.

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RECOMBINANT HUMAN GRANULOCYTE COLONY STIMULATING FACTOR (rhG-CSF): PLACEBO CONTROLLED STUDY IN NORMAL HEALTflYMALE VOLUNTEERS

PHARMACOLOGICAL STUDIES OF EXPERIMENTAL PNEUMONITIS INDUCED BY HETEROLOGOUS ANTI-RAT LUNG SERUM E. Maki, M. Nozaki and K. Tsurumi It has been reported that an immunological action is considered to be the main pathogenetic mechanism in certain forms of diffuse interstitial 'pneumonia in the human. Anti-rat lung sernm-induced pneumonitis in the rat is known as one of the experimental animal models of the pneumonitis. In this study, the properties of this animal model and its availability for the screening of drugs for treating human pneumonitis in which immunological reactions are involved were clarified. Anti-rat lung serum was obtained from rabbits immunized with soluble rat lung-extract antigen according to the usual method. When the rats were injected intravenously with the antiserum, the lungs showed a significant increase in wet and dry weight ] and 24 hrs after injection. In the latter ease, hemorrhage and exudation of serous fluid in the alveolar cavities, accompanied with cublodal swelling of alveolar epithelia and infiltration of inf!am_matorv ce!!s r were observed microscopically. Hemolitic complement units (CHse) reached the lowest level ] hr after injection of antiserum and restored by 72 hrs. In complement-depleted rats, the onset of this antiserum-induced pneumonitis was significantly inhibited. The antiserum showed a potential to induce platelet aggregation but this did not contribute to the onset of antiserum-induced pneumonitis. No release of chemical mediators from lung was observed in vitro by a direct application of the antiserum. From these results, anti-rat lung seruminduced pneumonitis is considered to be caused by a Type II reaction (Coombs & Gall). Using this model, many drugs were evaluated. Some drugs including steroids showed disease-inhibitory effects. Department of Pharmacology, Gifu University School of Medicine, 40 Tsukasa, Gifu, 500, JAPAN

N. Awata, J. Azuma, N. Mochizuki, T. Kaneko, A. Shimosaka, and F. Takaku The Phase I study was conducted to determine the safety, pharmacokinetics and biological response of rhG-CSF following single and multiple intravenous ( i v ) infusion and subcutaneous (sc) i n j e c t i o n . Subjects demonstrating no response to the skin prick test were allowed to proceed on study. SubJects received a placebo followed at 24 hours by a physical examination, measurement of vital signs, hematology, blood chemistry, coagulation, immunology and urinarysis profiles. Volunteers were required to show normal laboratory data, physical examination and WBC counts between 4,000 and 8,000/mm3RhG-CSF was wel~ to~erated in the dose range of O.l-3.0~g/kg

iv single infusion, 1.0 #g/kg/day iv 6 days infusion, 0.5 and 1.0 ~g/kg single sc injection and 0.5 #g/kg/day sc 6 days injection. RhG-CSF increased only neutrophil dose dependently and the peak count of neutrophil appeared ~.5-12.5 hours after each administration. The baseline neutrophil count before the administration on the 7th day reached twice higher than that of the 1st day after iv multiple dose, and 3 times higher after sc multiple dose. Neutrophil count returned to control level within 24 hours after discontinuation of rhG-CSF. No side effects were observed. Biological response of se dose was equivalent %o 3 times higher iv dose. The difference in the responses of iv and se administration in the same volunteers will be demonstrated in details. The 3rd Department of Internal Medicine, Osaka University Medical School. 1-1-50 Fukushima, Osaka 553, JAPAN Osaka Pharmacology Research Clinic. Pharmaceutical Department, Kirin Brewery Company Limited. The 3rd Department of Interna] Medicine, Tokyo University Medical School.

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COMPARATIVE STUDY OF IMMUNOSUPPRESSIVE EFFECT OF D O X Y C Y C L I N E A N D PREDNISOLONE S. A. Grando, B. T. Glukhenk~. A. P. Kostronuin, S. V. Demidov and T. A~ Koros~ash The effect of dox~cycline (D) and prednisolone (P) on the activity of T and B lymphocytes from the spleen of 96 normal guinea pigs was studied in ~in vitro experiments. We also investigated the effect of preincubation of splenocytes with D and P in different concentrations on spontaneous blast transformation of the mononuclears ~s well as their proliferation in the response to phytohemagglutinin (pHA), eoncanavalin A (Con A) and lipopolysaccharide (LF~ from E. coli. When assessing the results, also determined were the stimulation index (SI), i.e, (c.p.m. control lymphocytes) : (c.p.m. ly~uphecytes preincubated with D or P) and the in/qibitory index (II), i.e. (clhMP/cGMP lymphocytes, incub a t e d w i t h D or P) : (eA~P/oGMS control !vmphocytes), it was found that D inhibited lymphoproliferative response to PHA and Con A, while P to LPS. Inhibiting effect depended on concentration of the drqAgs and was directly proportional to the increase in D and P dosage. Minimum concentration, causing the 50 % SI decrease amounted to 2.0 ug/ml for D, and to 1.5 ug/ml for P. Selective immunosuppressive effect of D and P was realized by changing the ratio of intracellular concentrations of cAMP and cGM2 in immunocompetent cells. II of T lymphocytes, preincubated with D, 1.5 times exceeded this index for P, while II of B lymphocytes was almost 2.5 times higher in P versus D. The conclusion was made that D and P posses the marked immu_uosuppressive properties which became the most pronounced in D at concentration of 2.0 ug/ml, and in B at 1.5 ug/ml. Immunodermatology Unit, Chair of Dermato-u ology KSATID; 72 Saksagansky Str., Kiev-3~ USSR

INFLUENCE OF IMMUNITY ON TKE D~JG EFFECTS: PHARMACO~I~NOLOGY? O.VINA~ . According to a hypothesis (Vina9 1984) the binding of drugs to receptors is comparable to the binding of antigens to antibodies. If the process of binding is regulated in a comparable way, the effects of drugs which bind to receptors will be altered in immunocompromised patients. A group of phsrmecoresistant depressed patients improved when levamisol was added to antidepressants which had not helped them earlier. Their immune functions improved st the same time (Vins9 1987). In sn other study, the effects of a test dose of diazepam were compared in immunodefficient patients to its effects in pstisats with similar symptoms bat without immunological disorder. The results with respect to anxiolytic end sedative effects of diazepsm will be presented. If immunopharmacology deals with the effects of drugs on immunity, should we call it phsrmaco-immunology when studying the influence of immune functions on the drug effects? Vin8~, 0.: On the origin of receptors. Biol. Psychiet. 19,1273-1274, 1984. Vinag, 0., Poch, T., Vinagovg, E.: Levsmisol counteracts the resistance to antidepressants. Actlv.Nerv.Saper. (Prsgae) 29, 239-241, 1987. Joint Laboratory, Inst. Organlo Chemistry and Biochemistry, Czechoslovak Academ~ of Sciences and State Inst.for Drag Control, Srobgrov8 48, 1CO 41 Prague 10, Czechoslovskie.

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THERAPEUTIC DRUG MONITORING IN SWEDEN U. 8eraman. R. Dahlavist, J. HasselstrSm. D. Lee. I. Nordenstam*, E. Sanz. and F. Sieavist The use of therapeutic drug monitoring (TDM) for selected drugs, antibiotics excluded, was surveyed in Sweden (pop. 8.4 million) from 1982 to 1987. A mail and telephone questionnaire survey (100% response rate) identified 69 laboratories providing TDM, 58 for lithium, 45 theophylline, 39 digoxin, 35 carbamazepine and phenyloin, 32 phenobarbital, 21 valproic acid, 11 amitriptyline/nortriptyline, 8 nortripty]ine and c]onazepam, and 7 for one or several neuro~eptics. Over this six-year period increases in absolute numbers of analyses were observed for lithium, clonazepam, valproic acid, carbamazepine, neuroleptics, nortriptyline and amitriptyline, and lheophylline, and decreases for the remainder. The bulk of the 298,000 analyses in I987 were for digoxin (99,462), lithium (64,101), phenytoin and carbamazePine (38,000 each), and theophylline (25,822). The number of analyses were related to the respective drug sales (in DDDs per day) in 1987. Assuming that DDDs per day estimate patients on chronic therapy, the number of analyses per person l~eated was obtained: lithium (5.9), clonazepam (2.9), valproic acid (2.5), ethosuximide (2.3), carbamazepine (2.0), phenytoin (1.6), phenobarbital (1.2), digoxin (0.6), theophylline (0.4), amitrip. tyline or norlriptyline (0.2), and individual neuroleptics (_< 0.t). Factors associated with the relative extent of use of the respective drug level analyses may relate, among others, to the degree of selectivity in indications for therapy, the degree of clinician familiarity with the use of the various drugs, the market life of the drug, or the relative awareness of the available technologies. These data provide an indication of the extent of use of this medical technology. However, further research is needed to address not only the reasons for the observed differences in utilization but also the qualitative aspects of the use of therapeutic drug monitoring technologies (i.e. determinants of use, appropriateness, and impact). Department of Clinical Pharmacology of the Karolinska Institute at Huddinge University Hospital, S-141 86 Huddinge, and *National Corporation of Pharmacies, S-105 14 Stockholm, Sweden

OYNAMICALLY COMPLIANCE MONITORING - ITS UTILITY FOR THE INTERPRETATION OF DRUG TRIALS

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A DECADE OF THERAPEUTIC DRUG MONITORING IN A DISTRICT GENERAL HOSPITAL G.P.Mould and V.Marks The provision of a therapeutic drug monitoring (TDM) service has found widespread application in many huspitals. However the results are rarely interpreted adequately (Editorial, Lancet, ~, 309-310, 1985 ) and therefore a large percentage of results are inappropriately used. A pharmacist, experienced in drug assays and c/inical pharmacokinetics, working with Biochemists, can ensure results are properly used. We would like ~odeacribe our experience. A T D M service was started in Guildford in 1978. The assays were performed in a Clinical Biochemistry laboratory. The interpretation of the results and the pre-screening of requests were made by the pharmacist, based in the laboratory. Samples were received from a wide range of patients within the hospital and community. The requests for theophylline, digoxin, lithium, phenytoin, phenobarbitone, carbamazepine and sodium valproate for the 10 year period were scrutinized for their degree of documentation and reason for requests. Doctors action on the results were also noted. Taking digoxin as a example, a total of 991 requests from 696 patients were made in1978. In1988, atotalof920 requests were made from 800 patients. Documentation details were taken from a sample during both years. In 1978, a total of 149 out of 515 requests (38%) had inadequate documentation, whereas in 1988, the figures were 360 out of 509 (71%). This represents a significant improvement (X2=6.44;p(0.001). Results from the anticonv~lsants showed a high initialdegree of doc~entati0n ( 80% ) , which improved even further in 1988 to 95%. Other drugs showed similar improvements. Valproate measurements were the most ur~elpful. Doctors actions were monitored when a repeat request was made following a recommendation. This showed a positive trend towards improvement in patient control (eg digoxin :X 2 =6.44, p<0.1 ). We have shown t~mt the documentation of requests has improved~ and is now ~reater than that from other studies (M.J.Hallworth, Ann. Clin. Biochem. 2 5 , 1 2 1 - 1 2 8 , 1 9 8 8 ) . This il/ustrates the supervision of a pharmacist of T D M savices can lead to better documentation, and a more cost-effectiveuse of resources. Department of Clinical Biochemistry, St. Lukes' Hospital, Ouildford, Surrey, GUI 3NT, U.K.

COMPARISON OF S A L I V A S T I M U L A T I O N M E T H O D S F O R AN APPROPRIATE THERAPEUTIC DRUG MONITORING BY USING SALIVA SAMPLES S~Nagasako, Y.Katagiri, M.Hayashibara and K.Iwamoto

W.Krus~ G.Schlierf*and E.Weber# Indirect and d i r e c t metllods available for compliance measurement cannot evaluate the pattern of drug intake. Tile microprocessor technique has Pecome to f i l l this gap. A new microprocessor-based method of compliance monitoring (Medication Event ~ionitoring System,NEMS~"')was used to assess the adh,erence t o and the deviations from orescribed treatmeni~ witll Simvastatin once d a i l y in 12 patients with f a m i l i a l hypercholesterolemia (males 8,females 4, mean age 43 years). Each time of opening and closing of the medication container is recorded. Openings are recorded as presumptive doses. Mean t o t a l and LOL-cholesterol decreased s i g n i f i c a n t l y . However, the degree of l i p i d lowering effect was markedly d i f f e r e n t in individuals. A clear dose-response r e l a t i o n ship emerged from d i f f e r e n t degrees of compliance. Three types of medication errors were revealed by compliance monitoring: extra dose, omission of dose and deviation from the time schedule of dosing that had been recommended The mean compliance was 38% (range 33-114%). The average amount of drug taken in the evening, as i~ad been prescribed, was 63%. Detailed informations on medication managemen& or mismanagement are not available by other methods but the compliance monitoring. This technique w i l l decrease bias that is caused by non-compliance. The relationship between dose and response can be elucidated. Thus, the power of drug t r i a l s could be improved. Klin. Insti~ut for Herzinfarktforschung and Abt~ for Klin. Pharmakologie an der Med. Univ.-Klinik, Bergheimer Sta 8e 58, 0-6900 Heidelberg

It has been reported that saliva/serum (or plasma) drug concentration ratios are influenced by s o m e f a c t o r s s u c h as s a l i v a r y pH, flow r a t e a n d d r u g p r o t e i n b i n d i n g as w e l l as s e r u m (or p l a s m a ) p r o t e i n b i n d i n g of t h e drug. These factors and composition of saliva have been k n o w n to be i n f l u e n c e d by t h e method to stimulate salivation. In t h e p r e s e n t s t u d y , pH, flow rate and composition ( t o t a l p r o t e i n , Na +, K +, CI-, creatinine) of mixed saliva were c o m p a r e d by a p p l y i n g f o u r k i n d s of stimulation and collection methods in 10 normal male subjects. Each of pH, flow rate and composition (total protein, K + and creatinine) was significantly different among the methods. It w a s o b s e r v e d that the simplest method (i.e. mouth and tongue movement) had the smallest inter-individual variation of p H a n d r e l a t i v e l y small inter-individual variation of total protein a n d Na + concentration. Furthermore, the diurnal variation of pH, flow rate and composition was not observed by this method. These results suggest that mouth and tongue movement for salivation is very simple and suitable method for therapeutic drug monitoring by using saliva samples. In addition, this m e t h o d c o u l d be a p p l i e d to a p i l o t s t u d y on t h e relationship between concentrations of mexiletin~-HCl in saliva and serum after a single oral administration in n o r m a l s u b j e c t s . Department University Japan

of Pharmacy, Hospital, Enya-cho

Shimane Medical 89-I, Izumo 693,

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THE VALUE OF THERAPEUTIC DRUG MONITORING (TDM) IN EPILEPSY IN DE~ELOPING COUNTRIES: A HOSPITAL SURVEY H.S.Fraser, D.Davison, R.King and D. Corbin Epilepsy management is seriously deficiemt in developing countries. A Your part cross-sectional survey of diagnosis and treatment of epilepsy was undertaken in (i) a major hospital Emergency Dept (ED), (ii) Medical/Paediatric Outpatient Clinics (MPOC), (iii) Psychiatric and related institutions and (iv) Primary Care Clinics. A research nurse interviewed 90% of consecutive patients (or relatives) seen over 2-3 month periods in all four health care locations. This paper reports parts (i) and (ii). The 1 5 1 E D patients were older (36 ~ 9 years) than the 26] MPOC patients (26 ! 12, p < 0 . 0 1 ) with 30% of ED patients diagnosed as alcohol abusers (dependent, or > 3 drinks daily). Phenytoin was the most frequently used drug in both ED patients (56% alone and I|% in combination) and in MPOC patients (44% alone and 13% in combination). But in ED patients it was barely detectable ( < 2 pg/ml) more often (40%) than in MPOC patients (16%, X 2 = 16, P < 0 . 0 1 ) . In 45 of the ED patients (30%) seizures were alcoholrelated and of 31 receiving antiepileptic drugs blood levels of phenytoin were < 2 ~g/ml in 13 of 18 samples (72%), indicating very poor compliance. In contrast, in non-alcohol related ED cases, values < 2 pg/ml occurred in only 32% (X2 = ]8, P < 0 . 0 0 1 ) , and toxic levels in ]4%. Drug levels are indispensable in both ED and MPOC and should be available in all hospitals as an urgent assay, as one assay costs less than a 4-week prescription of phenytoin. Alcohol related seizures are an important cause of epilepsy in the developing world. This study shows that, in Barbados, 30% of patients with epilepsy seen in the ED with an acute seizure abuse alcohol; 70% showed barely detectable blood levels of phenytoin. Some of these acute seizures may therefore be due to drug and/ or alcohol withdrawal. Chronic use of phenytoin in alcohol abusers may be both ineffectual and hazardous. Faculty of Medical Sciences, University of the West Indies, Queen Elizabeth Hospital, Bridgetown, Barbados.

OPEN ADD-ON TRIAL OF LAMOTRIGINE 1N REFRACTORY EPILEPSY : EVALUATION OF EFFICACY AND TO• WITH THE AID OF PLA SMA DRUG LEVELS F. Pisani, M. Russo, R. Trio, A. Fazio, G. Oteri, M. Caputo, F. Romano, C. Artesi and R. Di P e r r i . Lamotrigine,a novel putative a n t i e p i l e p t i c drug,was given in an open add-on t r i a l to 30 pts with r e f r a c t o r y e p i l e p ~ (generalised and/or p a r t i a l seizures with or without sec= ondary g e n e r a l i z a t i o n ) . The d a i l y dose,given in two administrations,ranged betwe~ 100 and 400 mg and the observed plasma drug l e v e l s varied from 1.3 to 4.6 ug/ml. 4 pts had to discontinue the drug because of the onset of cutaneous rashes within the f i r s t week of treatment. Although a l l types of seizures seem t o b e n e f i t from the drug,the most evident a n t i e p i l e p t i c ef= f e e t was observed against generalized seizures and atypi= cal absences. The most frequent side e f f e c t s were headach% nausea,dizziness and sedation, hut t h e i r incidence was low and of pe~r clinical rclcvancc.

Neither changes in the laboratory safety parameters nor modifications of plasma levels of concomitant antiepilep= t i c drugs attributable to lamotrigine were observed during the period of treatment(4 weeks up to now). Clinica Neurologica la, Policlinico Universitario, 98013 Contesse-Messina, Italy.

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IS A FIRST WORLD THERAPEUTIC DRUG MONITORING (TDM) SERVICE OF BENEFIT TO EPILEPTIC PATIENTS LIVING UNDER THIRD WORLD CONDITIONS? M.L. McFadyen~ V. Hodgson~ R. M i l l e r ~ M. J u t a 2 Since April 1988 a TDM service has been offered to epileptic outpatients at Prince Mshiyeni Memorial Hospital. The patients are drawn from Durban townships as well as rural areas and their education and income varies accordingly. Approximately 4% of the 6000-7000 medical outpatients seen monthly are epileptics. A team approach (doctor, sister, pharmacokineticist and social worker) is being utilized at the weekly clinics. Blood sampling for TDM is done if the patient is uncontrolled and/or complains of side effects or has recently started taking phenytoin. Patients seen over 4 weeks in May and in November were divided into 4 categories (controlled (C); controlled with side effects (CSE); uncontrolled whilst taking medication (U) and defaulters/poor compliers (E)) and compared as follows:

CONVENTIONAL CARBAMAZEPINE: A C R O S S - 0 V E R STUDY

C MAY NOV

26% 59%

CSE 5% I%

U

D

NUMBER OF PATIENTS

30% 26%

38% 14%

61 167

The percentage of patients from whom blood samples were taken had fallen from 59% to 16%. There has been much improvement in the number of patients who are well controlled. This can be attributed, on the one hand to TDM, but patient education and counselling on epilepsy has probably played the major role in reducing the number of poor compliers. Wide inter-individual variation in the elimination capacity of phenytoin seen in the +/- 50% of patients on phenytoin necessitates TDM. TDM is very useful in a third world setting and can assist in conserving scarce resources provided it is used in a total care or team approach. I Drug Studies Unit, University of Durban-Westville, Private Bag X54001, Durban, 4000, South Africa. 2 Prince Mshiyeni Memorial Hospital.

VS CONTROLLED-RELEASE MULTICENTRE, DOUBLE-BLIND,

M. C a p u t o , R. C a n q e r , C.M. Cornaqgia, F. M o n a c o s G . C . M o n z a r G. Z a c c a r a r P . G . Zaqnonir a n d F. P i s a n i Efficacy and tolerability of a n e w c o n t r o l l e d release (CR) formulation of carbamazepine (CBZ) w e r e a s s e s s e d in a multicentre, double blind, cross-over trial. The pts studied were 48 e p i l e p t i c s ( 21 M, 27 F ; m e a n a g e 3 4 . 2 yrs ) on conventional CBZ monotherapy,with partial control of the seizures ( n = 22 ) or with intermittent side effects (n = 2 2 ) . E a c h p e r i o d of t h e c r o s s - o v e r c o n s i s t e d of a first titration phase (lasting up to 2 months) and a second phase of maintenance,lasting one month.At the end of the latter period,the number of s e i z u r e s , t h e incidence a n d e n t i t y of s i d e e f f e c t s and the daily fluctuations of plasma CBZ and CBZEpoxide levels were evaluated.The results of ower investigation are the following: (i) lower bioavailability of C R - C B Z a n d s u b s e g u e n t need of i n c r e a s i n g the daily dose ( 16% on average); (ii) lower oscillations of p l a s m a CBZ and CBZ-Epoxide levels during CR-CBZ (p < 0.01); (iii) r e d u c e d number of p a t i e n t s with side effects ( 6 pts on CR-CBZ vs 26 o n conventional CBZ, p < 0.01); (iiii) reduced seizure frequency per month during CR-CBZ (M• 6.3 ~ 1 5 . 6 v s 9 . 3 • 9.8, p < 0 . 0 1 6 ) . D u r i n g CR-CBZ therapy, 5 p t s b e c a m e s e i z u r e f r e e a n d 38 p t s (vs 15 on conventional CBZ) shifted from a t.i.d. to a b.i.d, regimen. Clinica Neurologica I,Policlinico,98013 Contesse - Messina , Italy.

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A KNOWLEDGE BASED SYSTEM FOR MONITORING PATIENT TREATMENT IN HEMATO-CANCEROLOGY A. Venot, P. Ferrand, J.F. Boisvieux, D. Pierre, V. Chirat, F. Dreyfus B. Varet and G. Strauch Caneerology and more specifically Hemato-Cancerology makes extensive use os complex therapeutic protocols. The related drugs are highly toxic and their effects have to be carefully monitored. The occurrence of side effects necessitates specific and complex additional prescriptions. Optimality of patient management in this context is far from being achieved in routine. Some of the necessary investigations or complementary treatments may be omitted. Customization of treatment may be inadequate. This is mainly due either to lack of expertise of part of the medical staff (new resident) or to the overload of raw information. The described system is a tentative solution to this problem and is aimed to help prescriptions to be both relevant and complete. Every day it proposes antimitotic and additional drug prescriptions as well as laboratory investigations necessary for the follow up of treatment. It is able to provide explanations, accepts supplementary prescription of the physicians after verifying its consistency. Different separate modules are used to represent the domain knowledge. Assessment and prediction of the patient state necessitated to decompose its representation into 9 subsystems (hematologic, renal, pulmonary, hepatic, cardio-vascular, cutaneous, infectious, neurologic, gastro-enterologie). Each subsystem state is inferred from raw clinical and biological data. Frotocols are represented as a set of task to be performed sequentially. Knowledges on drugs are encoded within a hierarchical framework. The implementation was performed on the basis of the essential expert system SESAM. This approach of computerized patient treatment monitoring is not restricted to the oncology domain and can be proposed for use every time drug prescriptions and monitoping are complex. IRT-ECLIMED, H~pital Cochin, 75674 Paris eedex 14; SIM, CHU Piti6-Salp@tri@re, Paris; Service d'h~matologie, H6pital Cochin, Paris, FRANCE.

LONG TERM MONITORING AND VARIABILITY OF AMIODARONE DISTRIBUTION IN PLASMA AND ERYTHROCYTES. T J B Maling, R I Fer~uson, C T Chen, S Heald and R W L Siebers.

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INTRAINDIVIDUAL VARIABILITY OF SERUM DIGOXIN CONCENTRATION DURING STEADY-STATE THERAPY Y.y. HSIEH, M.S. LIN, S.M. HSIEH, P. CHEN, J.R. JENG, W.P, LIEN The stability of Serum digoxin concentration (SDC) is studied by serial measurement of SDCs by radioimmunoassay in 106 patients during steady-state digoxin therapy. Eighty six patients (Group A) had no known factors which may affect the measurement of SDC (Group A-l: 54 outpatients; Group A-2: 32 in-patients) and 19 patients (Group B) either were treated with interfering drugs (16 cases) or had diseases (3 cases) kho%rn to affect the measurement of SDC. The mean postprandial SDCs (PSDCs) were significantly higher than the mean fasting SDCs (FSDCs) of Group A-I (0.96~0.43 vs. 0.86_+0.44 ng/ml, +11.6%, p<0.001, Student's paired t test) and Group A-2 (0.97+_0.57 vs. 0.81_+0.46 ng/ml, +16.5%, p<0.001), respectively. In contrast, the difference bewteeen the mean PSDCS (1.29~0.83 ng/ml) and FSDC (I.02~0.46 ng/ml) of Group B was statistically not significant (p=0.06). The mean PSDC of Group B were sginificantly higher than that of Groups A (1.29_+0.83 vs. 0.96_+0.49 ng/ml, p<0.05). The mean FSDC of Group B showed a trend of higher value than that of Group A (1.02+_0.46 vs. 0.83~0.45 ng/ml, p=O.O6). In 36 Group A-1 patients who had follow-up SDCs, variability between the first and the second SDCs examined by linear regression revealed excellent correlation (r=0.81, intercept=0.09 ng/ml, p < 0.0001 for FSDC; r=0.74, intercept=0.06 ng/ml, p < 0.0001 for PSDC). However, the PSDCs showed a trend towards greater variability than the FSDCs. Thus, in the absence of interfering factors, serial measurement of SDCs is remarkably stable in compliant patients. The PSDCs showed greater variability than the FSDCs, especially in the presence of interfering factors. Therefore, fasting blood sample is recommended for measuring SDC. Departments of Medicine, National Taiwan University Hospital, Cathay GeneralHospital and Tri-Service General Hospital, Taipei, Taiwan, Republic of China.

A concentration e f f e c t r e l a t i o n s h i p has c l i n i c a l v a l i d i t y only i f co n s i s t e h t l y demonstrated in the same individual at steady s t a t e , Within-patient variabili t y and compartmental r e l a t i o n s h i p s o f plasma and erythrocyte amiodarone (A), and desethylamiodarone (DEA) were defined in 12 c l i n i c a l l y stable pat i e n ts taking amiodarone 200 mg d a i l y f o r i - 3 years p r i o r to the study. Blood was sampled under standardized conditions at 3 consecutive monthly i n t e r v a l s , I year apart, All repeated measurements were included in the analysis. Despite constant dosage plasma A decreased from the f i r s t to the second year, mean • s . d . , 1.75 • 0.77 umol/L to 1.05 • 0.72 umol/L, P <0.001. The A cell:plasma ratio increased from 0.5 to 1.1, P <0.0001, but the DEA r a t i o remained unchanged. For the 2 years combined, the w i t h i n - p a t i e n t % c.v. was greatest f o r plasma A, 58.8% and l e a s t f o r plasma DEA, 44.7%, with erythrocyte A and DEA within t h i s range. Compartmental relationships reflected biological differences between A and DEA. Plasma A and DEA were s i g n i f i c a n t l y c o r r e l a t e d , r = 0.64, P <0.0001; e r y t h rocyte A and DEA were not, r = 0.13, P = 0.3. Although there was marked w i t h i n - p a t i e n t v a r i a b i l i t y in alpha i acid g l y c o p r o t e i n , % c . v . 49%, there was no c o r r e l a t i o n between plasma or er yt hr ocyt e A and serum alpha 1 acid glycoprotein concentration. The cause o f the w i t h i n - p a t i e n t v a r i a b i l i t y remains unexplained but precludes the use o f plasma or erythrocyte A or DEA concentrations as v a l i d dosage p r e d i c t o r s f o r r o u t i n e monitoring. Department of Medicine, Wellington School o f Medicine and Wellington Hospital, New Zealand.

EXPERIENCES WITH A DRUG MONITORING OF FLECAINIDE H. Stein~ U. Hoppe~ U. Gundert-Remy Flecainide is an antiarrhythmie drug, Class Io, with a known efficacy but also narrow therapeutic range, and death in patients treated with the drug has been associated with high plasma levels. Several factors, such as urine-pH, influence the clearance which exhibits an enormous interindividual variability. Hence the characteristics of the drug recommend therapeutic plasma level monitoring. In the course of an observational study designed to characterize other factors, which may influence the clearance of the drug, we measured plasma levels of patients consecutively included in the study using HPLC with fluorometric detection (J.U. Becker, J. Clin. Chem. Clin. Biochem. 22, 389 - 595, 198a). The topfit program assuming the open-onecompartment model with first-order-absorption was applied to calculate individual clearances using trough plasma levels 24 hours and 48 hours after the first dose. Repeated clearance estimation was done including the trough plasma levels obtained at days 4, 5 and 6. Complete data was available from 22 patients out of 24 consecutive patients. The initial dose was 2 x 100 mg daily in all patients and plasma levels at 48 hours ranged from 115 ng/ml to 439 ng/ml. At day 6 plasma levels were between 150 ng/ml and 788 ng/ml. Dose adjustments w e r e mode with two patients. Patient A received 2 x 150 mg/day after 96 hours, at day six his plasma level was at 270 ng/ml. Patient B received 2 x 200 mg/day, after 72 hours, at day six his plasma level was at 650 ng/ml. Clearances calculated using the 24 hours and 48 hours plasma levels were in accordance with the repealed clearance estimation in all but four patients when allowing for lag time, whereas not allowing for lag time 8 out of 22 data pairs were not in accordance. From our results we conclude that flecainide measurements are necessary and that a prediction of steady state levels can be done using the mentioned program and allowing for lag time. Institut fur Arzneimittel des Bundesgesundheitsamtes, SeestraBe lO, i000 Berlin 55

A 292

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A POSSIBILITY OF U S I N G S A L I V A S A M P L E S FOR THE T H E R A P E U T I C M O N I T O R I N G OF M E X I L E T I N E M.Hayashibaraf Y.Katagiri, S.Nagasako and K.Iwamoto Since, mexiletine-HC1 ( M e x ) has relatively narrow therapeutic range, its therapeutic m o n i t o r i n g by u s i n g b l o o d s a m p l e s is required. To investigate a possibility of predicting s e r u m Mex level f r o m the s a l i v a r y level, serum and s a l i v a r y l e v e l s of this d r u g w e r e compared in four normal male subjects who received a s i n g l e o r a l d o s e of 200 mg. Periodical blood samples ( 5 ml ) w e r e withdrawn at the midpoint of the corresponding period ( 5 min ) to c o l l e c t s a l i v a by m e a n s of m o u t h and tongue movement. S e r u m a n d s a l i v a r y level of M e x was determined by HPLC. The p r e s e n t d a t a analyses including estimation of the terminal elimination rate constant ( k e ) were carried out for the post-absorption phase ( i.e. 4 to 24 h ). P r e d i c t i o n of s e r u m d r u g level f r o m the salivary level was done according to Matin's equation. A l t h o u g h the observed and predicted ratio for s a l i v a / s e r u m total drug concentrations v a r i e d f r o m 3.7 to 7.9 and 1.0 to 6.6 among subjects, respectively, almost c o n s i s t e n t r a t i o w a s o b t a i n e d in the i n d i v i d u a l subject. The predicted serum drug levels were always higher than those observed in all subjects. H o w e v e r , the p r e d i c t e d k_ was a b o u t I to 1.5 t z m e s as l a r g e as t h o s e o b s e r v e d . The present f i n d i n g s s u g g e s t that t h e r e m a y be a possibility to use saliva samples for the t h e r a p e u t i c m o n i t o r i n g of Mex. Department University Japan

of Pharmacy, Hospital, Enya-cho

Shimane Medical 89-I, I z u m o 693,

CELIPROLOL DOSE RESPONSE IN HYPERTENSION J. C. Godfrey, Y. Chang, A. Stevenson, D. M. Joseph, W. D.

Michaells, K. D. Lamon Celiprolol (C), a highly Bi-Selective S-blocking agent with partial B~-agonist and peripheral vasodilating activity, was studied in 176 essential hypertensives at doses of 400, 800, and 1200mg QD vs placebo (Pbo), in a double-blind (db), parallel-group study. 3-wk Pbo run-in to baseline, 4 wk db on C or Pbo. Supine BP were reduced at end of 4 wks, compared to baseline, by syst/diast mmRg: Pbo, -2.2/-5.3; C400, -6.8/-6.5; C800, -10.8"/-9.1"; C1200, -9.4"/-8.1. *differences were statistically significant, compared to Pbo. ~ of patients (pt) with therapeutic response (sup. diast BP down to < 90 or by ! I0 rmmHg below baseline): Pbo 30~, C400 44%, C800 61%, C1200 58~. No dose-related reduction in heart rate was observed; small, clinically insignificant, random reductions were seen in C pt. Adverse Experiences (AE) were reported by 31% of Pbo, C400 36%, C800 50%, and C1200 35Z of pts. Most AE were mild or moderate. Severe AE (headache, dizziness) occurred in 1 P b o and I C400 pt. All drug-related AE resolved spontaneously. 2A-hr ambulatory BP monitoring pre- and post-db showed normalization of hypertension by all doses of C at nearly all time points, no effect by pbo. Trough BP reduction (24 hr) by C was ca 50% of peak at 4-6 hr post-dose. Serum Lipid profiles were obtained at entry, baseline, and end of study. Total cholesterol, LDL-C, and LDL-C/HDL-C decreased serially with time in all 4 groups, while HDL-C increased serially in all 4 groups, but no changes from baseline to end of study were statistically significant. Triglycerides and VLDL-C did not change in systematic way. Conclusions: C antihypertensive dose-response (manual, 24hr) plateaued atS00mg. C produced no dose-response with respect to heart rate or AE. Ambulatory results showed efficacy of all C doses over 24 hr. C was safe, well-tolerated, and effective in this study, c did not affect serum lipid profiles adversely. Rorer Central Research, Rorer Pharmaceutical Corporation, Horsham, PA 19044.

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A NEW HPCL METHOD TO DETERMINE LORAJMINE AND A J M A L I N E IN P L A S M A A N D URINE. D.Piovan,R.Padrini,R.Zordan,M.Ferrari Lorajmine (Lor) .the 1 7 - m o n o c h l o r o a c e t y l ester of a j m a l i n e (Aim). is currently employed as antiarrhythmic d r u g . L o t is r e a d i l y h y d r o l y z e d to A i m by a l k a l i n e pH a n d by plasma or tissue esterases. The a n a l y t i c a l m e t h o d s so f a r reported require extensive sample manipulation (alkalinization, solvent extraction) which may r e s u l t in L o t loss a n d c o n s e q u e n t A i m g a i n The m e t h o d h e r e d e s c r i b e d a v o i d t h i s d r a w b a c k . The assay steps are as follows: l)Blood esterases are blocked by adding neostygmine (20mg/l) 2 ) A i m ms f i r s t d e t e r m i n e d b y direct on-column injection according to a p r e v i o u s l y described method (R.Padrini et al. J Chromatosr. B i o m e d . Appl. 4 1 5 . 1 8 3 - 1 8 7 . 1 9 8 7 ) . 3 ) L o t is t h e n c o m p l e t e l y converted to Aim by strong alkalinization of p l a s m a a n d e x t r a c t e d with solvents (iOml heptane + 3% isoamyl alcohol) a l o n g w i t h the A i m p r e - e x i s t i n g in the sample; Lot concentration was determined by subtracting the [Ajm] d e t e r m i n e d at s t e p 2 f r o m [Ajm] o b t a i n e d at s t e p 3. This procedure also improves the Lol- d e t e c t i o n limit (ing/ml) s i n c e A i m ,unlike Lot, exibits a good fluorescence (ex : 2 8 0 n m ; e m . : 3 6 0 n m ) . T h e c a l i b r a t i o n c u r v e s f o r A i m w e r e l i n e a r up to lO00ng/m], with a coefficient of c o r r e l a t i o n a l w a y s g r e a t e r t h a n 0.99, and coefficients of v a r i a t i o n r a n g i n g b e t w e e n 3% a n d 8% a c c o r d i n [ to the drug concentration tested (5n~/ml 500ng/ml) . Some examples of pharmacokinetic a p p l i c a t i o n w i l l be p r o v i d e d . Istituto di Medicina Clinica - U n ~ v e r s i t a " d] Padova, v i a G i u s t i n i a n i 2. 1 - 3 5 1 0 0 P a d o v a .

DILEVALOL DETERMINATION IN PLASMAAND URINE BY HPLCFLUORESCENCE METHOD: COMPARISONOF TWO EXTRACTION PROCEDURES. R. Verbesselt, T.B. Tjandra-Maga and P.J. De Schepper Dilevalol (D), the RR isomer of labetalol, is anovel antihypertensive drug with both 82-agonist a c t i v i t y and vasodilatory action. Since pharmacokinetic studies and therapeutic drug monitoring need simple, rapid and accurate Dilevalol measurements, two HPLC extraction methods are compared, using either Prazosin (P) or Sch 37145 (S) as internal standard. Method-I is an organic extraction procedure: D and the internal standard (P or S) are extracted from alkalinized plasma or urine with diethylether and back-extracted in HCI 0.05 M. Method-II is a solid-phase extraction, using Bondelut Cl8 column: D and the internal standard (P or S) are selectively retained on the column at alkaline pH and eluted with a mixture of acetonitrile and 0.05 M ammoniumcarbonate buffer pH 9.5 (50/50, v/v). The eluates are injected on the HPLC-column: PRP-I 5 (150 x 4.1 mm) and separated witha mixture ofacetonitrile and 0.05M ammoniumcarbonate buffer pH 9.5 (35/65, v/v) as mobile phase at a flow rate of 0.5 ml/min. Thefluorescence detector was operated at 330 nm (excitation) and 415 nm (emission). No interference from other compounds were found in the chromatograms. Linearity of D extracted from plasma is from 5-250 ng/ml and from 25-I000 ng/ml for urine with both methods (R>O.g95). Intra-assay coefficients of variation are lower than 5%. Recovery of D from plasma and urine by method-I averaged about 75% and by method-If about 95 %. The limit of quantitation (using 0.5 ml plasma

or urine) is respectively 5 and 25 ng/ml. Comparing both extraction methods (using P or S as internal standard), one can conclude that both methods show similar good performance. Solid-phase extraction however, has the advantage of being simple and f a s t , with higher recoveries, suggesting this method appropriate for rapid analysis of c l i n ical samples. Obtained patients plasma p r o f i l e s of D demonstrate v a l i d i t y of the described methods. Dept. Clin. Pharmacol., K.U.Leuven, Gasthuisberg, B-3OOOLeuven

A 293

PP 13.28 THEOPHYLLINE

IN

PP 13.30 CHRONIC

OBSTRUCTIVE

PULMONARY

DISEASE

(COPD) J.F.HORGA, C.FAURA, A.SEVILLANO and M.HERNANDEZ We measured theophylline plasma levels in 89 patients (72 men, 17 women) with COPD, treated with either oral sustained release (70) or parenterai (19) theophylline~ at doses of 9 + 2 mg/kg/day. Drug dose was adjusted without theophylTine plasma levels control. The levels measured just before the first daily dose (trough levels) were ii + 5 ~g/ntl and the levels detemminated 4-6 hv after the--dose were 13 + 6 ~ / m l . 47% of the patients had levels under therapeutic values (< I0 ~g/ml). Patients were classified in three groups according to spirometric evaluation and subjective patient improvement; however, we did not find any difference in plasma levels of theophylline among the 3 groups: 12 + 5 jug/ml in non-controlled~ ii + 6 in mild-eontrol~ed, and 12 I 5 in well-controlled patients. In the 3 groups the percent of patients treated with steroids~ beta-agonist and antibiotics were similar. The number of patients with diuretics was higher in the non-controlled group. According to the plasma theophylline trough levels the patients were classified in other 3 groups: < 1 0 ~ g / m l ~ 10-20 ~g/ml and > 20 ~g/ntl. These different levels were not related to sex, age~ weight, route of administration~ number of patients with concomitant cardiac disease or co-administration of other drugs. We conclude that it is necessary to stablish an appropiate correlation between positive response and optingansern/m levels for the use of theophylline in COPD, and to avoid an unnecessary misuse of this drug in these patients. CLINICAL PHARMACOLOGY. uNIVERSITY OF ALICANTE. Apt. Correos 99, 03080 ALICANTE. SPAIN.

THE INFLUENCE OF THE APPLICATION OF THERAPEUTIC DRUG MONITORING ON THEOPHYLLINE UTILISATIQN IN A HOSPITAL SETTI NG R. Millerlr G. Pillay I and M.C. Kamdar 2 There is widespread documentation of the potential improvement in patient care when theophylline dose is individualised using pharmacokinetic principles. However most studies have measured the utility of therapeutic drug monitoring (TUM) programmes in terms of the achievement of a 'therapeutic' serum concentration with little emphasis on clinical control. Sixty one asthmatics on theophylline therapy were randomly selected from an out-patient Asthma Clinic at a South African hospital and included in a sO/dy to determine the influence of the application of TDM on tJleophylline utilisation. The majority of patients received a standard manufacturer's recommended dose at their initial consultation. Linear regression of dose versus serum theophylline concentration (STC) showed a poor correlation (r 2 = 11.99%). Twenty one patients (34%) were found to be clinically stable or well controlled on their initial dose while 40 patients were considered to be clinically uncontrolled as determined by the frequency of their emergency room visits and hospital admissions for treatment of acute exacerbations of asthma. In 5 of the 4 0 clinically controlled patients, STC's greater than 15ug/ml were recorded and further dose increases were considered potentially dangerous in these patients. In the remaining 35 patients, a programme of dose individua lisation using pharmacokinetic principles was implemented. At review, 3-6 months later, a statistically significant decrease in emergency room visits (p < 0.00001 ) and hospital admissions (p <0.001) was noted (sign test). The results confirm that theephylline dose individualisation using pharmacokinetic principles can significantly improve clinical control of asthma. I Department of Pharmacology, University of Dur ba nWes tville, Private Bag X54001 , Durba e, 4000, South Africa. 2 Department of Medicine, RK Khan Provincial Hospital, Private Bag X004, Chatsworth, 4052, South Africa.

PP 13.29

PP 13.31

INTRAVENOUS AMINOPHYLLINE IN THE EMERGENCY ROOM: USE OF RAPID PLASMA THEOPHYLLINE ANALYSIS AND COMPUTER-ASSISTED DOSAGE PREDICTION BY MEDICAL RESIDENTS. ..R.O.Day, R.J.Kino, G. Pearce and G. Fulcle. The ability of medical residents in the emergency department of a city teaching hospital to measure baseline plasma theophylline concentrations at the bedside (Syvva, Acculevel) and to operate a computer programme (Theophylline Program; Abbott) for the prediction of loading and maintenance dosages of intravenous aminophylline was investigated. Plasma theophylline concentrations, estimated one and six hours after commencement of aminophylline, were compared in patients dosed according to conventional or computer-assisted methods. Computer-assisted dosage prediction was associated with a higher proportion of theophylline concentrations in the therapeutic range at one (81 versus 26%; p < 0.001) and 6 hours (0 versus 10%; p < 0.001). Mean +_SD theophylline concentrations at 1 and 6 hours were 51.5_+36.3 and 59.7+ 35.4 for conventional and 68.8+ 16.0 and 69.8+ 17.1 Ixmol/L for the alternate method. These techniques were readily accepted by the medical residents. Dept of Clinical Pharmacology & Toxicology, St Vincent's Hospital, Darlinghurst, Australia, 2010.

LITHIUM MONITORING IN INDIAN POPULATION J.K. GRGVER, Department of Pharmacology, AllIndia Institute of Medical Sciences, Ansari Nagar, New Delhi-l10029 (IkDIA) 370 patients taking lithium carbonate for a t l e a s t 30 d a y s a n d n o t r e c e i v i n g a n y o t h e r medication were included in this study. On constant dose, serum lithium levels were f o u n d t o i n c r e a s e w i t h age, b u t w e r e l o w e r in patients o v e r 60 y e a r s . Patients improved clinically when maintained between 0.6-0.9 mmol/l of lithium. Most of the patients required dose between 600-900 mg per day to achieve this level. 1200 mg or higher dose w a s r e q u i r e d i n 25 p a t i e n t s . Six of these patients did not respond to lithium, while in others the serum lithium did not increase proportionately. Toxicity symptoms were seen at serum levels o f 1.0 m m o l / l w h i c h w a s i n t h e f o r m o f t r e m o r s o b v i o u s t o x i c i t y o c c u r e d a t l e v e l s a b o v e 1.8 mmol/l. There was a latent period of 12-18 hours between high serum lithium and appearance of toxicity. Indian patients require less dose)seasonal variation in l i t h i u m l e v e l s is a l s o s e e n .

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PP 13.32

PP 13.34

PYRIDOSTIGMINE PLASMA LEVELS AND NEUROLOGICAL SYMPTOMS IN PATIENTS WITH MYASTHENIA GRAVIS U. Breyer-Pfaff, A. Schmezer, U. Maier, A.M. Brinkmann and F. Schumm In nineteen patients suffering from generalized myasthenia gravis and receiving oral pyridostigmine treatment (90-370 mg/day in 3-4 doses), drug plasma levels and indices of neuromuscular function were investigated at intervals of 0.5-2 h during at least one dosing interval. Plasma pyridostigmine was measured by HPLC (Breyer-Pfaff et al., Clin. Pharmacol. Ther. 37, 495, 1985). Basal levels were always measurable, but time courses following ingestion of a dose (30-60 mg) differed widely among patients; ratios of average levels and daily doses varied 8fold interindividually, while intraindividual variation was 2fold in those six patients who underwent two or three investigations. Plasma level/dose ratios were not affected by concomitant administration of azathioprine, glucocorticolds or antisecretory drugs. Clinically relevant improvements of muscular strength were observed in half of the cases and reductions of neuromuscular block in a third. These changes exhibited significant correlations in the expected direction with plasma level changes in some of those cases where plasma levels increased by at least 25 ng/ml during the investigational period and attained maximal values between 45 and i00 ng/ ml. No such correlations existed in cases with smaller plasma level fluctuations and/or lower or higher peak levels. According to the score measuring muscular strength, patients with mean pyridostigmine concentrations above 80 ng/ml or peak concentrations above i00 ng/ml were in a poorer clinical state than those with intermediate levels, whereas drug doses did not differ between the two groups. These results when confirmed by independent studies should warn against the administration of high pyridostigmine doses without plasma level monitoring. Departments of Toxicology and Neurology, University of THbingen, D-7400 T~bingen, and Clinic of Neurology Christophsbad, D-7320 G~ppingen, F.R.G.

EVALUATION OF BAYESIAN FEEDBACK IN PATIENTS TREATED WITH TOBRAMYCIN H. J. Ledermann~ S. Vozeh~ G. Kaufmann~ B. Meyer~ M. Wenk, F. Follath We have developed an IBM-AT compatible Bayesian feedback program based on population pharmacokinetic parameters of tobramycin determined previously in our hospital. The program uses a two compartment model with a slow terminal elimination phase. The tobramycin clearance is a function of the patient's actual renal function and the volume of the central compartment is proportional to bodyweight. With the help of a feedback measurement the individual concentrations are predicted and recommendations for adjustment made, taking into account the estimated prediction interval. The performance was prospectively evaluated in 25 patients treated with intravenous tobramycin. Serum concentrations Were ohtained 2 and 6 h after the dose for individual dosing adjustmenn and again after a mean of 5 (range 2-8) doses on the individual dosinN regimen at i, 2 and 6 h. Sufficiently high concentrations early after the dose (i h, CI) are important for optimum therapeutic efficacy. The average concentration (Cav) was used as a measure of drug accumulation and potential toxicity. The recommendations obtained by the program resulted in both effective and safe serum concentrations. Only 2 (8 %) patients had C1 below the lower limit of the 68 % prediction interval calculated by the program and 4 (16%) had Car above the upper bound of the 68 % interval. The root mean squared error was 29 %, 24 % and 24 % for CI, C2 and Cav , respectively.

PP 13.33

PP 13.35

H U M A N S C A L P H A I R A S E V I D E N C E OF I N D I V I D U A L D O S A G E H I S T O R Y OF H A L O P E R I D O L T. U e m a t s u , R. S a t o and M. N a k a s h i m a W e c o l l e c t e d the h a i r s a m p l e s and m o r n i n g p r e d o s e p l a s m a f r o m e a c h of p a t i e n t s , w h o w e r e a d m i n i s t e r e d h a l o p e r i d o l at c o n s t a n t d a i l y d o s e s for >4 M and w h o s e c o m p l i a n c e s w e r e good. I to 2 c m - l o n g p o r t i o n s n e a r e s t the r o o t s of a few h a i r s t r a n d s w e r e c o m p l e t e l y d i s s o l v e d in 2.5N NaOH. H a l o p e r i d o l in it or p l a s m a w a s e x t r a c t e d and m e a s u r e d by a r a d i o i m m u n o a s s a y . Haloperidol l e v e l s in the h a i r (Y: n g / m g hair) c o r r e l a t e d w e l l b o t h to t r o u g h p l a s m a l e v e l s in the m o r n i n g (X: ng/ml) a n d the d a i l y d o s e s (X: p g / k g B , W . ) , i.e., Y = I . 3 8 X + 2 2 . 5 (r=0.772, n=39) (P<0.001) a n d Y=0.i50X+12.6(r=0.555, n=40) (P<0.001), r e s p e c t i v e l y . T h e h a i r s f r o m p a t i e n t s , in w h o m the d o s a g e h a d b e e n c h a n g e d w i t h i n a few m o n t h s p r i o r to h a i r s a m p l i n g , w e r e s e c t i o n e d i n t o 0.5 or 1 c m - l o n g p o r t i o n s f r o m the r o o t s and the d r u g a m o u n t in e a c h p o r t i o n w a s m e a s u r e d . W h e n t h e h a i r w a s a s s u m e d to g r o w at the r a t e of 1 cm/M, i n d i v i d u a l d o s a g e h i s t o r y c o u l d be in g e n e r a l d e d u c e d f r o m the d i s t r i b u t i o n of d r u g level a l o n g the h a i r length. W e c o n d u c t e d a l s o a p r o s p e c t i v e study, in w h i c h h a i r s w e r e c o l l e c t e d at the t i m e of c h a n g e of p r e s p r i p t i o n , i, 2, 3, 4 and 5 M a f t e r the c h a n g e f r o m t h e p a t i e n t s , to w h o m h a l o p e r i d o l h a d b e e n a d m i n i s t e r e d for >4 M a n d j u s t c h a n g e d to a n o t h e r drug. T h e t i m e of c h a n g e in p r e s c r i p t i o n c o u l d be d e d u c e d f r o m the d i s t r i b u t i o n of d r u g a m o u n t a l o n g the h a i r length, a s s u m i n g the h a i r g r o w t h of 1-2 cm/M. T h e f a c t t h a t the h a i r c o n t a i n s d r u g a m o u n t s c o r r e s p o n d i n g to t h e d o s e s g i v e n w a s s u p p o r t e d by an a n i m a l s t u d y u s i n g rats. F r o m t h e s e r e s u l t s , t h e h u m a n s c a l p h a i r c o u l d s e r v e as a tool for monitoring individual dosage history. D e p a r t m e n t of P h a r m a c o l o g y , H a m a m a t s u U n i v e r s i t y S c h o o l of M e d i c i n e , H a m a m a t s u 431-31, J a p a n

C L I N I C A L E V A L U A T I O N OF N E T I L M I C I N ( N T L ) PHARMACOKINETIC DOSAGE REGIMEN Y.Nagayama, S.Takahashi~ K.Shinozaki*~ Y.Takao*~ Y . T a n a k a * and K . S o m e y a W i t h the p u r p o s e to e v a l u a t e N T L p h a r m a c o k i n e t i c dosage regimen, we examined NTL pharmaeokineties of i n t r a v e n o u s i n f u s i o n a n d i n t r a m u s c u l a r i n j e c t i o n in 6 h e a l t h y v o l u n t e e r s u s i n g o r d i n a r y ( O L S ) and B a y e s i a n ( B L S ) l e a s t s q u a r e r e g r e s s i o n p r o grams. In 24 e o u r s e s ( l h o u r i n f u s i o n g r o u p ; n = l l , 1.5 h o u r s i n f u s i o n g r o u p ; n = 1 3 ) for 22 p a t i e n t s , we d e t e r m i n e d i n d i v i d u a l d o s a g e a n d interval u s i n g B L S p r o g r a m . The p r e d i c t a b i l i t y of s e r u m NTL concentration, clinical efficacy and toxicity w e r e e v a l u a t e d . M e a s u r e d c o n c e n t r a t i o n s after i n t r a m u s c u l a r i n j e c t i o n w e r e in g o o d a g r e e m e n t w i t h the c a l c u l a t e d c o n c e n t r a t i o n s b a s e d on one c o m p a r t m e n t m o d e l in h e a l t y v o l u n teers. The p r e d i c t a b i l i t y in the case of 1 0 n g i n f u s i o n p e r i o d was b e t t e r t h a n in the case of short i n f u s i o n p e r i o d . S e r u m N T L c o n c e n t r a t i o n s of 6 ( 5 h . 5 % ) c o u r s e s in i h o u r i n f u s i o n g r o u p and 9 ( 6 9 . 2 % ) courses in 1.5 h o u r s i n f u s i o n g r o u p w e r e w i t h i n t h e r a p e u t i c range. In 1 h o u r inf u s i o n group, the r e s i d u a l p e a k and t r o u g h c o n centrations(predicted-measured concentrations) were 0.60~2.31(mean~S.D.) and - 0 . 7 3 • respectively. In 1.5 h o u r s i n f u s i o n g r o u p , the r e s i d u a l p e a k and t r o u g h c o n c e n t r a t i o n s w e r e - 0 . 1 7 ~ i . 0 3 and - 0 . 3 2 • respectively. The p r e d i c t a b i l i t y in 1.5 h o u r s i n f u s i o n g r o u p was b e t t e r t h a n in 1 h o u r i n f u s i o n group. Of the p a t i e n t s , 72.7% in 1 h o u r i n f u s i o n a n d 6 1 . 5 % in 1.5 hours i n f u s i o n w e r e e f f e c t i v e . T h e r e was no c l i n i c a l s i g n i f i c a n t d i f f e r e n c e of e f f i c a c y b e t w e e n b o t h g r o u p s a n d no e v i d e n c e of t o x i c i t y . The 3rd dept. of I n t e r n a l M e d i c i n e , the dept. of P h a r m a c y * , St. M a r i a n n a Univ. S c h o o l of M e d . ~ 2-16-1, Sugao, Miyamae-ku, Kawasaki, Japan.

Division of Clinical Pharmacology, Department of Medicine, University Hospital (Kantonsspital~ CH-4031 Basel, Switzerland

A 295

PP 13.36 Pharmacokinetics of Zidovudine (AZT) in chiidrens after oral administration R. GARRAFFO*, A. DEVILLE**, P. LAPALUS*, R. MARIANI**, L. CHANALET* *Department of Pharmacology; **Department of Pediatry, Hospital University, Nice

PP 13.38 WHOLE BLOODCYCLOSPORINEMONITORINGBY SPECIFIC- AND NONSPECIFIC IMMUNOASSAYS:LONG-TERMVARIATION IN RATIOS OF NONSPECIFIC / SPECIFIC MEASUREMENTSIN HEART-TRANSPLANT PATIENTS T.B. Tjandra-Maga, R. VerbesseIt and P.J. De Schepper

Zidovudine (AZT, RETROVIR*), is a new pyrimidine analog which demonstrated 'in vitro" an important effect on reverse transcriptase and protection against the infectivity and cytopathic effect of HIV viruses. Clinical trials have shown it's potential benefit in the treatment of AIDS, specially in the prolongation of life. Seventeen ohildrens with HIV infections have been treated by AZT orally with a posology ranging from 20 to 200 mg, 4 to 6 time a day and their age ranged between 3 or 14 years. They underwent a pharmacokinetic test after several days of treatment when steady:state was reached. The blood determinations of A Z T a n d its glucuronide (G AZT) have been performed by HPLC. The estimation of pharmacokinetics parameters was model independant. Their mean values and standard deviations were for AZT : the area under curve (1291 _+808 ng/ml.h-1), the Cmax (928 + 721 ng/ml), the MRT (1,55 + 0,8 h), the total body clearance (72,3 + 54,2 I/h) and the half-life (0,9 _+ 0,4 h). The values for G AZT were : the AUC (3471 _+ 2054 ng/ml.h-1), the Cmax (1620 +_ 1051 ng/ml), the MRT (2 _+ 0,8 h) and the half-life (1,1 _+ 0,5 h). The great inter individual variability suggests that drug monitoring will be of interest in the management of the AZT treatment.

A v a i l a b i l i t y of Specific- and Nonspecific i mmunoassays (IA) using a n t i b ~ e c i f i c for CyA and with broader spectrum of c r o s s - r e a c t i v i t y (CyA + Metabolites) enables monitoring of CyA alone or with CyA Metabolites. Our previous study to compare ~ e c i f i c and nonspecific I A - k i t s for CyA q u a n t i t a t i o n vs. a s-se-ie-ctive HPLC method (whole blood trough samples from renal- and bone marrow transplant r e c i p i e n t s ) , showed spec. monocl.-3H RIA SandimmunR to r e s u l t in close agreement with HPLC; while the nonspec. polycl.-FPIA Abbot-TDx consistently showed m u l t i p l e - f o l d higher values r e f l e c t i n g detection of CyA + Metabolites. Calculated regression equations were respectively 3H RIA = 1.38*(HPLC) + 13.97 (n=76, r=0.945) and FPIA = 3.25* (HPLC) +57.38 (N=76, r=0.784). We now report our observations on the pattern of w i t h i n - p a t i e n t and i n t e r - p a t i e n t changes in the high proportions of CyA + metabolites vs CyA in the blood, as reflected in changes in the Ratios between nonspec./spec, measurements, estimated by nonspec. FPIA and spec. 3H RIA, in whole blood trough samples from a t o t a l of 14 heart-transplant patients receiving regular CyA therapy during long-term (6- up to 12-months) follow-up. Soon a f t e r transplantation (during f i r s t lO-days) mean SD trough values (in ng/ml) by specific RIA, averaged 218.1 • 40.6 and by nonspecific FPIA, 866.7 ! 189.9 with mean nonspec./spec, r a t i o of as high as 4.24 +0.94, range: 2.99 to 6.23. DUring the f i r s t 3 months post-Transplant the mean r a t i o s varied between 2.85 and 3.88. Further serial observations however showed widely variable r a t i o values, with no clear trend to decline to low values within the f i r s t 3-months as e a r l i e r suggested by others. Our results f u r t h e r indicate f a i r l y s i m i l a r d i s t r i b u t i o n of cyclosporine blood levels within presumed therapeutic ranges for both the specific and nonspecific cyclosporine measurements. Dept. Clin. Pharmacol., K.U.Leuven, Gasthuisberg,B~O00 Leuven.

PP 13.37

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MONITORING OF CICLOSPORIN CONCENTRATIONS IN RENAL TRANSPLANT PATIENTS H.G. Trautsch-F6rster~ I. Waqnerr St. Bauer, W.Blank , R.G.Alken, H.Hfiller It. was the aim of the work to improve i n d i v i d u a lization of ciclosporin therapy using different methods of monitoring, different kinds of sample matrix and pharmacokinetic parameters. Ciclosporin concentrations in plasma and venous blood were determined using an "in house" modification of the monoclonal specific radioimmunoassay developed by Sendoz Ltd., and a high performance l i q u i d chromatography method. In parallel c a p i l lary blood obtained from a finger stab and c o l l e c t e d onto filter paper was assayed for ciclosporin content. With the help of this simple sampling method patients can collect their own samples and transport the specimen in an envelope. We have investigated the accuracy and reproducibility of the method in comparison w i t h that of conventional methods. The method is suitable for the therapeutic drug monitoring of long term patients. Institute of C l i n i c a l Pharmacology, HumboldtUniversity, POB 140, Berlin, 1040, GDR

CORRELATION BETWEEN CYCLOSPORINE METABOLITE M-17 CONCENTRATIONS MEASURED BY HPLC AND SPECIFIC AND NONSPECIFIC RIA DETERMINATIONS M. Wenk, R. Holdener and F. Follath The problem of cyclosporine (CSA) drug level monitoring in patients after organ transplantation is still not resolved. Recent investigations have shown a considerable in vitro immunosuppressive effect of the main metabolite M-17 which may contribute to the therapeutic activity of CSA. However, the concentration ratio between M-17 and CSA varies considerably among patients and concentration of M-17 can exceed the parent compound 2 - 3 fold. In the present study, the M-17 concentrations in whole blood of patients after renal or bone marrow transplantations were measured by HPLC and correlated to the differences between nonspecific and specific RIA determinations (~RIA) using the polyclonal (RIA I) and the specific (RIA II) and nonspeciffc (RIA III) monoclonal RIA kits (Sandoz, Basel), A good correlation was found between CSA measured by HPLC and RIA II (y=l.004x+17, r=0.983). The correlation between the M-17 concentrations a n d ~ R I A was ~• better (p<0.001) using RIA !II than with RIA I (r=0.897 and r=0.612, respectively). The improved results with the new monoclonal polyvalent antiserum can be explained by its higher crossreactivity with M-17 (76% vs. 32%). The concentrations of metabolites M-I, M-8, M-18 and M-21 were small in comparison to M-17 in most samples. From these results it can be concluded thatY~_RIA using RIA II and III gives a good estimate of the M-17 concentration independent of the CSA concentration. The practical relevance of M-17 formation has to be studied further. Division of Clinical Pharmacology, Department of Medicine, University Hospital (Kantonsspital), CH-4031 Basel, Switzerland

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COMPARISON OF 3 IMMUNOASSAYSAND AN HPLC-METHOD FOR CYCLOSPORINE AND ITS METABOLITESIN WHOLEBLOOD T. Zeugin and B. Frey Cyclosporine A (CsA) therapy in transplanted patients must be individualized, because of the narrow therapeutic window. HPLC- and R I A - methods, however, are cumbersome and t i m e consuming, Recently a polyclonal FPIA (Abbott, Cham, Switzerland) has been developed allowing analysis within 40 min. Our aim was to compare blood levels by FPIA to levels obtained by other immunoassays and an HPLC-method. The results of the regression analysis of the FPIA- and the polyclonal RIA (Sandoz) levels of 79 l i v e r ( L ) - and 72 kidney(K)-transplanted patients were as follows: Y X N Slope Intercept R Range ng/ml FPIA Abbott vs Sandoz L 79 1 . 4 5 -7.88 0.91 <50-2085 Abbott vs Sandoz L 29 1 . 2 9 -30.47 0.94 <50-700

Abbott vs Sandoz K 72 1.34 -68.68 0.96 <50-1408 Abbott vs Sandoz K 63 1.18 -26.55 0.95 <50-<700 We followed a l i v e r patient up to 77 days post transplantation. Comparing her FPIA-levels to the polyclonal RIA (Sandoz), to a monoclonal RIA (Cyclotrac) and to an HPLC-method, we calculated the r a t i o s of the three antibody methods and the HPLC-method: Method Ratio CV % N Abbott/HPLC 3.75 + 1.14 30.5 % 19 Sandoz/HPLC 3.14 + 0.63 20.1% 31 Cyclotrac/HPLC 1.38 • 0.34 23.7 % 31 Our results show that the FPIA-method and the polyclonal RIA are comparable, FPIA results being on average 1.3 times higher than RIA (Sandoz). This r e l a t i o n s h i p is p a r t i c u l a r l y close within the therapeutic range, i . e . up to 700 ng/ml. In l i v e r transplanted patients, CsA metab o l i t e s seem to d i f f e r from renal transplants: even the monoclonal RIA shows a r a t i o of 1.38 to HPLC. Clearly, the FPIA-method is at present a suitable approach for every day c l i n i c a l practice. Dept. of Clinical Pharmacology, University of Berne, Murtenstrasse 35, CH-3010 Berne (Switzerland)

VALIDATION OF AN EX VlVO PLATELET FUNCTION TEST BASED ON A NOVEL IN VITRO MODEL OF THROMBOSIS IN A PHASE I TRIAL W.G. Eisert, C.A.P.F. Su, G. Nehmiz and T.H. MSIler Platelst inhibitors are usually evaluated in clinical phase I trials by aggregometry in platelet rich plasma ex vivo. We have established an alternative method and tested its accuracy and limitations. Mural thrombus formation is measured in an in vitro model of a deend0thelialized vessel wall using whole blood (T.H. MLiller et al., Thromb. Haemostas. 58, 155, 1987), Anticoagulated whole blood (250 Id) is allowed to flow over a thrombogenic subendothelial matrix. Adherent platelats are fluorescently labelled. The adhesion and aggregation of platelets on the matrix are quantified by automated morphometry of fluorescence microscopical images. tn the first application of this method in a clinical trial we have compared the platelet inhibition by oral administration b.i.d, of 500 rng aspirin or 25 mg aspirin combined with 200 mg dipyridamole for 3.5 days in a randomized double-blind, placebocontrolled cross-over study in 9 healthy male volunteers. Blood was taken before (day 1 : 9 a.m.) and twice after the last (day 4: 9, 11 a.m.) treatment. In contrast to high interindividual variations (coefficient of variation of 20%-50%) the intraindividual variations were considerably smaller. For the placebo treatment the mean coefficient of variation for the mean area of all platelets/aggregates was 14% within the 2 h interval at day 4 and 27% within 3 days. For longer periods (3, 6 weeks) the intraand interindividual variations were no longer different. The method was able to discriminate between placebo and verum: aspirin as well as low-dose aspirin combined with dipyridamole reduced the mean area of all platelets/aggregates and also of large aggregates compared with placebo (p< 0.05). In conclusion, this novel in vitro model of thrombosis introduces a powerful tool for reliable analysis of platelet function ex vivo in whole blood into clinical pharmacology. Dr. K. Thomae GmbH, Birkendorfer Str. 65, D-7950 Biberach

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PHENPROCOUMON-PLASMA-ELIMINATION IN PATIENTS M.Simon,U.VSlker,J.X.de Vries,I.WalterSack,E.Weber P r e v i o u s l y the o n l y r e p o r t s c o n c e r n i n g the p l a s m a e l i m i n a t i o n of the oral anticoagulant phenprocoumon (P) w e r e in vol u n t e e r s or i n t o x i c a t e d p e r s o n s . We stud i e d the e l i m i n a t i o n in 12 i n p a t i e n t s (5 f e m a l e , 7 m a l e , a g e 44 to 75 years). B e c a u se of i n v a s i v e d i a g n o s t i c / t h e r a p e u t i c p r o c e d u r e s the n e c e s s a r y a n t i c o a g u l a t i o n was i n t e r r u p t e d for 7 to 36 days. The total p l a s m a c o n c e n t r a t i o n of P w a s det e r m i n e d by H P L C w i t h f l u o r i m e t r i c det e c t i o n . The p l a s m a e l i m i n a t i o n h a l f life was c a l c u l a t e d a c c o r d i n g to g e n e r a l l y applied methods. The e l i m i n a t i o n h a l f life v a r i e d b e t w e e n 76.1 a n d 273.6 h o u r s (mean 156.7 hours). T h e r e was no c o r r e l a t i o n w i t h age. O n l y one p a t i e n t , w h o s e e l i m i n a t i o n h a l f life was 91.2 hours, r e c e i v e d an i n t e r a c t i n g d r u g (colestipol) a c c o u n t i n g for the small value. The r a n g e of i n t e r i n d i v i d u a l h a l f lives w a s c o n s i d e r a b l y g r e a t e r than p r e v i o u s l y k n o w n (ratio of l a r g e s t to smallest value 3.5 in this s t u d y , 1.8 f r o m l i t e r a t u r e ) . B e c a u s e of the g r e a t v a r i a t i o n in p l a s m a e l i m i n a t i o n h a l f life of P it is a b s o l u t e l y n e c e s s a r y to p e r f o r m c o a g u l a t i o n t e s t s in o r d e r to a s s u r e a safe m a r g i n p r i o r to i n v a s i v e p r o c e d u dures.

INHIBITION OF EX VIVO - PLATELET AGGREGATION: THE COMBINATION OF LOW-DOSE ASPIRIN WITH DIPYRIDAMOLE IS SUPERIOR TO EITHER COMPONENT ALONE T.H. M611er, H. Weisenberger, R. Brickl, C.A.P.F. Su, G. Nehmiz and W,G. Eisert Platelet - vessel wall interactions in whole blood as well as cyclooxigenase inhibition in platelat rich plasma were analyzed ex vivo in a randomized, double-blind, placebo-controlled study. Four groups of 24 healthy volunteers each were treated orally b.i.d, for 3.5 days with either 200 mg dipyridamole (sustained release preparation, D), 25 mg aspirin (A) or the combination of both drugs (Asasantin, D+A). Blood was taken before (day 1) and 2h after the last (day 4) treatment. Malondialdehyde production in platelet rich plasma was measured after stimulation with arachidonic acid. Anticoagulated whole blood was moved over a thrombogenic subendothelial matrix synthesized by cultured endothelial cells. The number and the area of single platelets and platelet aggregates adherent to the matdx were measured by automated morphometry of fluorescence microscope images. The relative inhibition (+ S.E.) calculated from the differences between day 4 and day 1 was for : treatment I n / cyclooxigenase !platelet aueregation Placebo I 23 I -2.2% _+2.7% I 6.2% + 4.2% D (200 mg) j 22 I 3.8% _+3.4% I 19.8% • 6.7% A (25 mg) I 23 I 96.5% • 1.4% I 53.7% _+4.9% D+A I 24 I 96.1% +_ 1.0% t 71.4% _+3.7% Despite the almost complete Suppression of the cyclooxigenase activity by low dose aspirin, platelet aggregation in whole blood was inhibited by only 54%. In addition, dipyridamole further reduced the size of aggregates (P<0.01, two-fold analysis of variance) in correlation with the dipyridamole plasma levels (P<0.05, analysis of covariance). In conclusion, dipyridamole both alone and as addition to lowdose aspirin inhibited platelet aggregation in whole blood ex vivo in an in vitro model of thrombosis. Dr. K. Thomae GmbH. Birkendorfer Str. 65, D-7950 Biberach

A b t e i l u n g fur K l i n i s c h e P h a r m a k o l o g i e , Medizinische Universit[tsklinik, Bergheimerstr. 58, D - 6 9 0 0 H e i d e l b e r g

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"EX VIVO" E F F E C T OF D I L T I A Z E M ON P L A T E L E T AGGREGATION AND RELEASE REACTION C. Marena, G. Bertolino, P. Noris, G. P i l e t t a and C.L. B a l d u i n i We have studied in healthy subjects the effect of a single a d m i n i s t r a t i o n of t h e c a l c i u m c h a n n e l b l o c k e r d i l t i a z e m (120 m g p.o. of a G a c e l l s l o w - r e l e a s e f o r m u l a t i o n ) o n "ex v i v o " p l a t e l e t a g g r e g a t i o n and r e l e a s e reaction. For c o m p a r i s o n w e i n v e s t i g a t e d in t h e s a m e s u b j e c t s t h e e f f e c t o f l o w d o s e a s p i r i n (50 m g p.o.) and of a s p i r i n a s s o c i a t e d w i t h d i l t i a z e m . P l a t e l e t a g g r e g a t i o n and A T P r e l e a s e w e r e s t u d i e d in PRP 2, 6 a n d 24 h. a f t e r d r u g i n g e s t i o n b y t h e Born's method and by the luciferin-luciferase method respectively. The results we obtained m a y b e s u m m a r i z e d as f o l l o w s : a } d i l t i a z e m significantly inhibited platelet aggregation only when epinephrine and low dose collagen w e r e the s t i m u l a t i n g a g e n t s ; a large and s i g n i f i c a n t i n h i b i t i o n of A T P r e l e a s e w a s o b s e r v e d w h e n p l a t e l e t s w e r e s t i m u l a t e d w i t h low and h i g h d o s e o f e p i n e p h r i n e , c o l l a g e n , A D P and p a l red agonists (epinephrine+ADP and epinephrine+ collagen b ) t h e i n h i b i t o r y e f f e c t of d i l t i a z e m on platelet aggregation was lower with respect t o a s p i r i n , w h i l e b o t h t h e d r u g s h a d a similar effect on platelet release reaction c)diltiaz e m d i d n o t p o t e n t i a t e t h e e f f e c t s o f aspirin. In conclusion, diltiazem had a strong inhibitory effect on platelet release reaction, while il l i t t l e a f f e c t e d p l a t e l e t a g g r e g a t i o n . D e p a r t m e n t o f I n t e r n a l M e d i c i n e , U n i v e r s i t y of Pavia, 27100 Pavia, Italy.

EFFECTS OF DESMOPRESSIN ACETATE (DDAVP) ON PIATEIET AGGREGATION AND HAI940STASIS AFrE~ CARDIAC ~ Y . T.L.G. Andersson, J.O. Solem, L. Tengborn, E. Vinge DDAVP increases plasma levels of von Willebrand factor antigen (vWF:Ag) and factor VIII coagulant activity (VIII:C) and can reduce bleeding in patients with mild haemophilia A, yon Willebrand's disease and some forms of platelet function defects. It has been suggested that DDAVP also may be used to reduce the bleeding tendency following cardiac surgery with extracorporeal circulation. The effects of DDAVP on platelet aggregation, plasma levels of vWF:Ag and VIII:C, bleeding-time and blood loss were studied in 19 patients undergoing aortocoronary bypass surgery. The study was placebo-controlled, double-blind, randomized, with parallel groups. Following termination of extracorporeal circulation, DDAVP (0.3 ~g/kg BW) or placebo was infused over 15 minutes. Postoperatively, before infusion, levels of VIII:C and vWF:Ag were normal in beth groups. After infusion VIII:C had increased in beth groups (DDAVP: + 0.37 + 0.25 IU/ml, placebo: + 0.16 + 0.16 IU/ml, median levels _+ quartile deviation; ns between groups). DDAVPtreated patients had a greater increase in vWF:Ag levels (+ 0.41 _+ 0.33 IU/ml) than the placebo-treated (- 0.01 _+ 0.33 IU/ml; p < 0.02). The aggregatory response to adenosine-all-phosphate (ADP) and ristocetin sh~r an essentially normal pattern and did not differ significantly between the groups, although it tended to be greater with DDAVP. There was no difference in bleeding-time or blood loss. We conclude that in uncomplicated coronary bypass surgery, a DDAVP-induced increase in vWF:Ag is not accompanied by enhanced platelet aggregation or reduced bleeding. Department of Clinical Pharmacology, University Hospital, S-221 85 Lund, Sweden

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ANTIAGGREGANT EFFECT OF GUARANi: THERAPEUTIC DRUOMONITOR ING OF METHYIXANTINES. M.Ivany-Silva, L.F.Figueira, J.G.N.Tavares, O.Papini, S.R. C.J.Santes, D.F.A.Chamone.

P L A T E L E T F U N C T I O N IN T Y P E I D I A B E T E S M E L L I T U S l . A u r s n e s and J. J e r v e l l D e s p i t e S e v e r a l s t u d i e s on p l a t e l e t f u n c t i o n in p a t i e n t s w i t h type I d i a b e t e s m e l l i t u s , the l i n k i n g of h y p e r - r e s p o n s i v e n e s s ex v i v o w i t h t h r o m b o - e m b o l i c r i s k in v i v o r e m a i n s e n t i r e l y h y p o t h e t i c a l . Indeed, if the g e n e r a t i o n of an a g g r e g a t i n g a g o n i s t w a s i n c r e a s e d in vivo, one m i g h t s p e c u l a t e that agonist-spesific desensitization should r e s u l t in a d i m i n i s h e d r e s p o n s e to the e x o g e n o u s a g o n i s t ex vivo. T h i s idea is s u b s t a n t i a t e d b y the f o l l o w i n g findings: F r o m ten t y p e I d i a b e t i c s a g e d 23 - 53 years, and ten c o n t r o l s 9 m l of b l o o d w a s d r a i n e d into I m l of s o y b e a n t r y p s i n inhibitor. In 2.5 m l of the b l o o d b e t a - t h r o m b o g l o b u l i n (BTG) w a s d e t e r m i n e d in p l a s m a a f t e r a d d i n g p l a t e l e t i n h i b i t o r s and c e n t r i f u g i n g at a h i g h g - f o r c e at 4~ The r e m a i n i n g b l o o d w a s e i t h e r r e s t e d on the b e n c h or c e n t r i f u g e d at r o o m t e m p e r a t u r e for 10 m i n at 50 g, and p l a s m a BTG d e t e r m i n e d . The levels of BTG (ng/ml• were: U n s t i m u l a t e d c o n t r o l s a m p l e s 28~11, s t i m u l a t e d ( c e n t r i f u g e d at r o o m t e m p e r a t u r e ) 124+53; u n s t i m u l a t e d p a t i e n t s a m p l e s 26+]I, s t i m u l a t e d ( c e n t r i f u g e d at r o o m t e m p e r a t u r e ) 70• p=0.01 for d i f f e r e n c e b e t w e e n the t w o g r o u ~ s of s t i m u l a t e d samples= Our o b s e r v a t i o n s s u g g e s t that p l a t e l e t s f r o m p a t i e n t s w i t h type I d i a b e t e s are p a r t l y d e s e n s i t i z e d as a r e s u l t of a n a b n o r m a l in v i v o stimulation. Consequently pharmacological i n t e r v e n t i o n s in d i a b e t i c s should be d i r e c t e d at c o r r e c t i n g this a b n o r m a l i t y . Dep. of P h a r m a c o t h e r a p e u t i c s and R i k s h o s p i t a l e t , U n i v e r s i t y of Oslo, 0316 B l i n d e r n , Oslo, N o r w a y

Guaran~ crude powderextracted from the seeds of Paud/inea cupana (var.sorbilis) contains caffeine, 1,3,7,-trimethylxantine. As dipyridamole or papaverine, caffeine inhibits cyclic phosphodiesterase (E.W. Salzman, Ann.N.Y.Acad.Sci. 1972, 201: 61) involved in platelet aggregation induction. After ingestion of this product, another methylxantines can be identified in blood or urine. In a {andoms pla~_e bo study 14 healthy volunteers weighing 70~2Kg, aged 2 5 3yr (X~SI~4) were investigated before and after ingestion of 4 o~ 8g of crude powder of Guarani, 8/8h. Methylxantines as caffeine, theobromine and theophylline were monitor e d b y HPLC using a sensitivemicrotechnique. Plasma levels of these methylxantines showed to be dose dependent.Linear correlation was found only between caffeine plasma levels and antiplatelet effect of Guarani. Based on this study, Guaran~ crude powder showed to reduce platelet aggregation in whole blood byenzymatic inhibitionanddecreasingthe uptake of plasma adenosine. A c ~ l a t i o n can be clinically relevant mainly for patients with liver or kidney impairments.

Center of Studies on Clinical Pharmacology - Heart Institu te of Medical School University of Sao Paulo - Av.Dr.Eneas Carvalho Aguiar, 44 - 05403 - Sao Paulo - SP - Brazil.

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AA-2414 - A NOVEL AND LONG ACTING THROMBOXANE (TX) A2 RECEPTOR ANTAGONIST Nishikawa,K., Ashida,Y., Terashita,Z., Kuriki,H., Nakamura, N.* and Shimizu,M.** Central Research Division, New Product Planning & Development Division*, Takeda Chemical Industries, Ltd., Osaka; Osaka-Minami National Hospital**, Osaka, Japan AA-2414, (~)-7-(3,5,6-trimethyl-l,4-benzoquinon-2-yl)-7phenylheptanoic acid, inhibited the contractile responses of guinea-pig tracheal(PA2:7.69) and parenchymal(PA2:8.29) strips to U-46619(a TXA2 mimic) and that of rabbit aorta strips(PA2:8.28 ) to U-44069(another TXA 2 mimic). It inhibited the aggregation of guinea-pig platelets induced by U-44069, arachidonate and collagen with IC50 values of 2.34.9x10-7M and the specific bindin~ of [3H]U-46619 to washed guinea-pig platelets(IC50:8.2xl0- M). In guinea-pigs, AA2414(0.08-1.25 mg/kg, p.o.) dose-dependently inhibited bronchoconstriction and thrombocytopenia induced by the TXA2 mimics;the inhibitory action at doses of 0.3-1 mg/kg lasted more than 24 hr after administration. Experimental allergic asthma in guinea-pigs was inhibited by AA-2414(0.3-5 mg/kg, p.o.) and thrombosis in rabbit carotid artery, endotheiium of which was injured by perfusing with 0.25% pronase, was inhibited by AA-2414(I0 mg/kg, p.o.). The pharmacokinetics and pharmacodynamics of AA-2414 were investigated in healthy male volunteers who received a single oral dose of 5 to 20 mg or multiple doses of i0 mg b.i.d.(placebo controlled studies) for 7 days. AA-2414 was rapidly and well absorbed from the digestive tract, and the maximum blood level was found about 2 hr after administration. The half-life(Tl/2~ ) of elimination from the blood was about 22 to 24 hr. Mainly unchanged AA-2414 was detected in the blood; I0 to 15% of the dose was excreted in the urine. AA-2414 after dose(5 to 20 mg) and after multiple doses(10 mg b.i.d, for 7 days) inhibited ex vivo platelet aggregation stimulated by U46619 or collagen. All dosing regimens of AA-2414 were well tolerated without any subjective or objective side effects. These results show that AA-2414 is a potent and long acting TXA2/PGH2 receptor antagonist.

INFLUENCE OF A Tk~OMBOXANANTAGONIST ON GLOMERULAR FILTRATION A N D R B N A L PLASMA FLOW IN MAN Ch. Hagena, E. Besenfelder, G. Neugebauer Daltroban[4J[2~(4~chlorobenzenesulfonylamino)ethyl]benzene acetic acid) has been characterised as a specific and selective thromboxane receptor blocker. In a double-blind randomized cross-over trial we stu~ed the influence of 800 mg daltroban on the hacnmdynamJcs of the kidney. 45 min after oral achinistration of daltroban or placebo ]0 healthy male volunteers received 0.7 g para-aminohippuric acid (PAH) intravenously injected over 1 min and 5.25 g inulin over 5 .fin. Blood samples were taken and urine was collected for two hours after the start of injection. Plasma samples were assayed for PAN and inulin and urine samples only for PAH by HPLC. The renal clearance of PAH was calculated from AUC0_24h/Ae0_2h resprescnting renal plasma flow (RPF) and total inulin clearance (D/AUC) was taken as renal clearance representing glomeru]ar filtration rate (GFR). The following results were obtained:

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ANTAGONISM OF COLLAGEN-INDUCED PLATELET AGGREGATION EX-VIV0 IN VOLUNTEERS BY GR32191, A THROMB0XANE A 2 RECEPTOR BLOCKING DRUG P Lumlev. R J Keerv. J E Kensington and M Thom~8 GR32191 i s a potent thromboxane (Tx) Am receptor blocking drug which when administered to man-produces a marked and sustained antagonism of platelet aggregation ~nduced ex-vivo by the TxA~ mimetic, U-46619 (M Thomas et al., Thromb Haemostas 58, 181, 1987). Collagen, an important stimulator of platelet aggregation, induces its effect partly via platelet-derived TxA 2 . The present studies were therefore designed to establish the magnitude and duration of action of GR32191 administered orally to health~ volunteers upon collagen-induced platelet aggregatlon ex-vlvo in whole blood. In an initial open study 4 male volunteers (29-35 years) received a single 40mg dose of GR32191 and platelet aggregation to both collagen and U-46619 assessed prior to dosing and i~ 2, 4, 6, 8, 12, 24 and 48 hours after dosing. GR32191 produced a maximal antagonism of collagen-induced aggregation for up to 12 ho~rs after dosing with a residual antagonism still being apparent for up to 48 hours. This duration of antagonism was mirrored using U-46619 as the aggregatory agent. A further 12 male volunteers (22-43 years) were'randomised to receive either GR32191 (80mg followed by 40mg 12-houriy for i0 days) or matching placebo and aggregation to collagen and U-46619 monitored both before dosing and 12 hours after doses i, 2, 4 and 20. In the 6 volunteers given GR32191 a maximal antagonlsm of collagen-lnduced platelet aggregation was present after all doses. The sensitivity of platelets to collagen was unaffected by placebo treatment. In the GR32191 treatment group, U-46619-induced platelet asgregation was also markedly antagonised at all time polnts. Since the interaction of platelets with collagen in the subendothelial lining of blood vessels is a ma~or stimulus to platelet activation in vivo, GR32191 may be of clinical benefit in various forms of occlusive vascular disease. Glaxo Group Research, Ware, Hefts., UK.

PHARMACOKINETICS OF CGS 13080, A THROMBOXANE SYNTHASE INHIBITOR IN KIDNEY TRANSPLANT PATIENTS. A. Rakhit, P. Robertson, T.N. Thompson, J. Turk, A.N. Kotake, M.L. Foegh, and F.L. Douglas.

GFR (m'l/min) RPF ~hl/min) Placebo 129,9 625,9 Daltroban 119,8 ~ 477,5. p <0,05 vs. ~p l a c e b o , Wilcoxon matched p a i r rank t e s t GFR decreased s i g n i f i c a n t l y by 7,8% and RFF by 23,7%. Whereas the i n f l u e n c e of d a l t r o b a n on RPF may be e x p l a i n e d by i n h i b i t i o n of t u b u l a r s e c r e t i o n of PAH, t he r e d u c t i o n i n GFR can onl y s p e c u l a t i v e l y be a t t r i b u t e d t o an i n f l u e n c e on t he r e s a n g i a l c e l l s i n the glomcrulus l e a d i n g t o a change i n f i l t r a t i o n surface area. Boehringer Hannheim GmbH, Klinische Pharmakologie, Sandhofer Str. 116, D-6800Mannheim 31

CGS 13080 is a ~ synthase inhibitor (TXSI) that demonstrated inhiblton of platelet ~ formation in normal volunteers. Because of its short half-life, the inhibitor was administered by constant intravenous infusion for seven days to 18 kidney transplant patients to evaluate its effect on suppression of thromboxane during periods of rejection. The dose of TXSI ranged from 0,04 to 0.5 mg/kg/hr. The patients also concomittantly received the standard immunosuppressive therapy (azathioprine, cyclosporine A and prednisone). As expected, the plasma concentration of CGS 13080 reached rapid steady state. The steady state concentration (CPs~ ), however, demonstrated large intersubject variability with a poor correlation (p > 0.05, multi-r 2 = 0.20) between Cp~, and rate of infusion (R. ). This relationship howeve%, improved (p < 0 001, m u ~ l - r = 0.69), when conce1_~t~on was normahzed wlth serum creati,ine values (SCR) in each patient9 The calculated steady state clearance (Cl) also demonstrated an exponential decline with increased SCR ( p < 0.001, multi-r ~ = 0.92). Measurement of serum TXB~ demonstrated an almost immediate complete inhibition, even at the lowest dose (0.04 mg/kg/hr) administered. This inhibition was sustained during the infusion periodand rapidly returned towards the preinfusion values during the post infusion period. Clinical Biology Research, CIBA-GEIGY Corp., Sunm~it, NJ, USA.

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DISTURBED ACID-BASE BALANCE FOLLOWING METHYLPARATHION INGESTION IS NORMALIZED BY THE PAF ANTAGONIST WEB 2086. G.Muacevic Ingestion of the organophosphorus i n s e c t i c i d e , methyl parathion, is characterized by r e s p i r a t o r y system damage. As part of studies to i n v e s t i g a t e whether the novel PAF antagonist, WEB 2086, is able to influence the course of methyl parathion t o x i c i t y , rats were dosed with 20 mg/kg methyl parathion p.o. and 15 min l a t e r blood p02, pCG2 and pH were measured. Methyl parathion treatment reduced mean p02 from 102 to 12 mm Hg, as well as increasing pC02 and decreasing pH values. Pretreatment with I0 mg/kg WEB 2086 i . v . 2 minutes before parathion prevented these blood gas e f f e c t s . A curative e f f e c t has been seen too. In addition to the more or less standard symptoms and signs of poisoning by organophosphorus compounds c e r t a i n other actions not f a l l i n g into one of the usual three categories of action: muscarinic, n i c o t i n i c and central nervous system have been reported ( f o r example thrombosis, embolism or hypercoagulation). In our opinion WEB 2086 might provide a worthwhile addition to a n t i c h o l i n e r g i c substances in the therapy of human organophosphorus poisoning. Department of Pharmacology, Boehringer Ingelheim KG D-6507 Ingelheim/Rhein, West Germany

LEUKOTRIENE PROFILE OF ON LINE EXCTRACTION: STATE.

HUMAN NEUTROPHILS BY HPLC WITH APPLICATION TO THROMBOEMBOLIC

F. Tursi, P. Catalani, P. Cremonesi, P. Del Soldato and *G.C. Maggi. Neutrophil-derived oxygen products and lipoxygenase (LOX) metabolites have been proposed as critical mediators of cellular injury in severe pathological states (J.M. Harlan ,Blood 65,513,1985). Preliminary data on activation of neutrophils isolated from patients reported to suffer from thrombotic desease showed a decrease in chemiluminescence (CL) response and an increase in LTB4 production in respect to control. In order to extend such observation to other 5-1ipoxygenase products a rapid and sensitive HPLC method with an on line extraction of the metabolites connected to a 6 port switching injector was developed. Such method allows the determination of the complete profile of LOX derived products without the time consuming organic solvent extraction and is based on an isocratic elution. The complete analysis leads to the determination of 5(s)HETE, 12(s)HETE,15(s)HETE,LTB4,LTC4,LTD4,LTE4 in less than 35 minutes. The methodology was applied to the determination of LTs profile produced by A23187-stimulated human neutrophils,isolated from blood samples of patients with thromboembolic (pulmunary, periferic) episodes in the acute phase, as well as in a group control. PMN chemiluminescence and myeloperoxidase release was also evaluated and tentative correlation performed. Italfarmaco Research Center,Via dei Lavoratori 54,20092 Cinisello Balsamo,and *Dept. of Cardiology, Ospedale Bassini, Cinisello Balsamo, Milano, Italy.

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HUMANKINETICS AND TOLERABILITY OF INTRAVENOUSMK-571, A NEW LEUKOTRIENE (LT)D4 RECEPTORANTAGONIST. A. Van Hecken~ P.J. De Schepper, D.J. MargoIskee~ J.Y.K.~ Hsieh~ R.S.~ Robinette~ K.H. Jones, J.D. Rogers.

THE D I L E M M A OF T H E O P H Y L L I N E AND M E T O C L O P R A M I D E P H A R M A C O K I N E T I C L I N E A R I T Y OR N O N L I N E A R I T Y IN PATIENTS J. P o p o v i 6 T t has been s u g g e s t e d that in some c h i l d r e n and a d u l t p a t i e n t s d i s p r o p o r t i o n a t e i n e r e a s e in steady-state serum theophylline concentration f o l l o w s an i n e r e a s e in dosage. P r e v i o u s s t u d i e s h a v e s h o w n that m e t o c l o p r a m i d e in low d o s e s f o l l o w s n o n l i n e a r r a t h e r than the first order kinetics. N i n e t e e n a s t h m a t i c c h i l d r e n (I-14 years) w e r e g i v e n a m i n o p h y l l i n e i n t r a v e n o u s l y in d o s e c o r r e s p o n d i n g 3 - 5 . 5 mg/kg. On a m u l t i p l e dose s c h e d u le of a m l n o p h y l l i n e 3 d i f f e r e n t s t e a d y - s t a t e " t h r o u g h " l e v e l s of s e r u m t h e o p h y l l i n e in 31 adult asthmatic patients were obtained. Metoclop r a m i d e was a d m i n i s t e r e d o r a l l y in m u l t i p l e doses to a g r o u p of 31 p a t i e n t s (3xi0 and 3x12.5 m g / d a y ) . S e r u m t h e o p h y l l i n e and m e t o c l o p r a m i d e c o n c e n t r a t i o n s w e r e m e a s u r e d by HPLC. The m e t a b o l i s m of t h e o p h y l l i n e in 4 a s t h m a t i c c h i l d r e n f o l l o w s n o n l i n e a r k i n e t i c s r a t h e r than the f i r s t o r e d e r k i n e t i c s . In 6 a d u l t a s t m a t i c p a t i e n t s the r a t i o of per cent i n c r e a s e in s e r u m t h e o p h y l l i n e level to per cent i n c r e a s e in dose was a p p r o x i m a t e l y 1.5. In 5 p a t i e n t s the r a t i o of per cent i n c r e a s e in s e r u m m e t o c l o p r a m i d e level to per cent i n c r e a s e in dose was a p p r o x i m a t e ly 2. Data f r o m the p r e s e n t r e p o r t are c o r r o b o r a t i v e of the p r e s e n c e of n o n l i n e a r k i e n t i c s for at least one of the p a t h w a y s of t h e o p h y l l i n e and m e t o c l o p r a m i d e e l i m i n a t i o n in s o m e t r e a t e d patients. D e p a r t m e n t of P h a r m a c o l o g y , F a c u l t y of M e d i c i n e , h a j d u k V e l j k o v a 7, 2 1 0 0 0 Novi Sad, Y u g o s l a v i a

MK-571 [(• chloroquinolin-2-yl-(E)-ethenyl) phenylnonanoic acid] is a selective LTD4 antagonist, with greater potency in the (+) enantiomer. This double-blind, randomized, placebocontrolled study assessed safety and preliminary pharmacokinetics of rising doses of I.V. MK-571 in healthy men. Two alternating panels where studied, with 4 subjects rereiving single doses of 25, 250 and IO00 mg (Panel A), 4 receiving lO0, 500 and 1500 mg (Panel B), and 2 per panel receiving placebo. MK-571 was weli tolerated; one subject reported a single episode of loose stools after each o f 3 doses (lO0, 500 and 1500 mg). No laboratory abnormalities were found. Plasma drug profiles were obtained by assaying plasma samples stereospecifically by HPLCfor the isomers of MK-571. Plasma profiles for each enantiomer increased with increasing MK-571 dose; the mean AUC increased disproportionately greater than the dose. Apparent half-lives ranged from l to 5 hrs for both enantiomers, while the (§ appeared to be eliminated faster than the (-) enantiomer. Apparent volume of distribution was small for both enantiomers (+ lO l ) . For the 1500 mg dose, mean maximumplasma concentrations ( ! S.D.) of 167 • 12 and 142 • 19 ~g/mlwere achieved for the (+) and (-) enantiomers respectively; < 0.5 % of this dose was excreted unchanged in the urine in 24 hours. MK-571 is a novel LTD4 antagonist, well tolerated at doses l i k e l y to be effective in the treatment of asthma. Its pharmacokinetics at these doses may be nonlinear; this possibility is currently under study. Dept. Pharmacology, University of Leuven, B-3000 Leuven, Belgium, and Merck Sharp and DohmeResearch Laboratories, Rahway, N.J., U.S.A.

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PP 14.02 PERFORY~NCE OF CONVENTIONAL AND D-OPTI;~L DESIGNS PLANNED FOR MITOXANTRONE KINETICg M.C. Lsunay, A. Iliadis and J.P. Cano Optimal design~ have been an ethical aim of clinical pharmacokinetics for many years : the number of sampling times can be reduced and the parameter estimates of a known model provided by D-Optimality are more precise. But this method requires a preliminary knowledge of the model parameters ; to improve this knowledge, a bayesian Dsequential procedure was developed (M.C. Launay, 12th II~CS World Congress, Vo].5, iSl-lS3, 1988). Four sampling protocols including 12 time-points (twice the number of the model 'parameters) were defined over a 72 h interval : the first was based on sensitivity functions, the second on geometric sampling and the two last onD-Optimality. Besides, a previous pharmacokinetic study showed that a three compartment model described best Mitoxantrone data obtained from 14 subjects. Population characteristics (mean vector and covariance matrix describing interindividual variability were computed and used to generate randomly 28 sets of parameters, the reference values. With them, concentration levels were simulated for each protocol and short infusions of mitoxantrone (12 ~/m2]. Comparison w a s made on the model parameter estimates (exponents and coefficients) by computing predictive performances (bias and precision). A t a first glance, the only 22 sensitivity fL!nction estimate sets were excluded because of high values of bias. A Friedman non par~fletric test on the 28 sets obtained by the 3 other designs showed a significantly reduced bias when samples are planned optimally. Moreover, bias and precision of clearance (Cl) and half-life (T~) (D-block design) raise when population dispersion increases. With a D-sequential one, the opposite effect is observed and performances are much better (bias = -4.07%, precision = 26.5%, for T~) than those obtained with the D-block design (27.3 and 63.5% respectively). C] is estimated by under 1.1S 1/h and T~ by over 14.~ h wPth the D-block schedule (p 0.05). INSERM U278, Facult@ de Pharmacie, 27 bd J Moulin 13385 MARSEILLE Cedex 5

PP 14.04 MOMENT ANALYSIS IN COMPLEX PHARMACOKINETICMODELS BYMEANS OF SIMULATION S.Primo2i~,*R.Karba, A.Mrhar, F.Kozjek Behaviour of moment p ~ i ~ - ~ r a m e t e r s was studied in complex compartmental model environment. A six-compartment model including linear and nonlinear parameters, previously developed for pharmacokinetic analysis of nifedipine following oral dosing was used for the purpose. Changes of moments in the sampled and nonsampled compartments of the model were studied as functions of model parameter changes ( i . e . drug l i b e r a t i o n delay, v a r i a t i o n of l i b e r a t i o n rate and extent, variation in elimination rate k i n e t i c s ) . The extents of changes in model parameters were in accordance to observed v a r i a b i l i t y in the nifedipine plasma concentrations database. Analog-hybrid computer was used for the simulation study. Model substructure was developed for calculation of areas and moments for each of the model compartments. Analog computer enabled parallel computing of a l l moment parameters by means of exact function integration. As output, time p r o f i l e s of moment parameters were obtained in graphic form. I t was established that the moments are sensitive descriDtors of changes in the p r o f i l e s induced by the variations in the parameters of the model. Use of such models is warranted in the analysis o f specific and discontinuous plasma p r o f i l e s . In this case, moments are worthy addition as they r e f l e c t the changes in the system often better than model parameters. In nonsampled compartments, a l b e i t losing t h e i r residence time concept, moments present a numeric measure of the shape of the p r o f i l e which can serve for q u a n t i t a t i v e and s t a t i s t i c a l evaluation of changes in the studied systems. University E.Kardelj Ljubljana, Faculty of Natural Sciences and Technology: Department of Pharmacy, A{ker~eva 9, 61000 Ljubljana, YUGOSLAVIA *Faculty of Electrical Engineering, Tria~ka 25, 61000 Ljubljana, YUGOSLAVIA.

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EVALUATION OF THE P H A P ~ C O K I N E T I C FACTORS THAT DETERMINE THE TIME TO REACH STEADY STATE FOLLOWING SUSTAINED RELEASE DOSAGE M. S.S. Chow, H. Sun The time to reach steady state following intravenous or irrm~ediate release dosage is dependent on elimination rate constant or half-llfe. It is unknown whether this is the case with sustained release dosage. Based on a one compartment model, we have derived an equation to calculate the specific fractional steady state achieved at any time after initiation of an oral sustained release dosage regimen. This equation takes into account rates of release (Kr), absorption (Ka), and elimination (K) constants as well as sustained release fraction (Fs) and immediate release fraction (l-Fs) of the dosage form. Using this equation and assuming Ka is large compared to Kr and K, multiple simulations were performed to evaluate the effects of Kr, K, and Fs. These simulations showed, for example, that when K changes from 0.05 to 0.3 hr -I (with other factors remaining constant), the time to achieve 90% steady state decreases from 54 to 23 hours. A change of Kr in the same manner produces similar results. However, a change of Fs from 0.5 to i increases this time from 28 to 34 hours. Our simulations indicate that Kr, K, and Fs have independent effects on the time to reach steady state. The time is prolonged as Kr or K becomes smaller and as Fs becomes larger. Conclusion: (i) Following an oral sustained release dosage, the time to reach steady state is highly dependent on Kr and K, and somewhat less dependent on Fs. (2) Our present equation provides a method for estimating time to steady state following such a dosage and may be a useful tool for therapeutic drug monitoring in certain patients. University of Connecticut, School of Pharmacy and Hartford Hospital, Hartford, CT 06115 USA

COMPARISON OF METHODS FOR PHARMACOKINETIC PARAMETERS ESTIMATION. HOW TO DECREASE THE NUMBER OF PLASMA SAMPLES? L.Delcroix. J.L. Brazier. E.Vermeulen. C.Dumarest*, p.Maire*. We have measured the pharmacokiuetic parameters estimates of Gentamicin in a reference group of theoretical patients in order to compare three estimating methods corresponding to three softwares. To achieve this goal, a reference population was computer generated. For 20 patients, plasma levels containing a random analytical error calculated from the assay error function were analysed according to a one compartment open model. The procedures used for calculation were : - A PoweU algorithm and unweightod least squares estimation, after peeling, on eleven plasma levels according to the general methodology used for clinical experimental pharmacokinetics (S1PHAR, 1984-1988). - A Nelder-Mead algorithm and weighted non linear least ~uares estimation on four samples. Two of them, were drawn at optimal times for Vd and Ke estimation respectively. (D'ARGENIO D.Z., 1981). - A Nelder-Mead algorithm, with Bayesian estimation on one plasma level drawn at 1.44 tl/2 after the end of infusion (JELLIFFE R.W., 1986). The pharmacokinetic parameters calculated from these 20 patients were first compared to the reference one obtained from the plasma samples before analytical error application. The parameters of the regression line arc presented on the following table. Algorithm I Poweil I Nelder-Mead non linear I Nelder-Mead Bayesian Slope I 0.9406 I 1.0705 I 1.0707 Trust intervall 0.6056-1.27551 0.9286-1.2125 I 0.9303-1.2111 Secondly, a statistical comparison of these phurmacokinetic parameters (ANOVA) showed no significant difference (p=4.84%) between the three methods under the used conditions. The absolute difference (2.10-2 h-l) between the Ke values (around 0.320 h-l) is too slight as to cause any significant clinical modification. Thus, a MLS method using four plasma levels can offered reliable .estimations without any reference population, The same reliability can be obtained from only one plasma sample with the Bayesian method as far as the subject is part of the population used as reference for the calculation. L.E.A.C.M., CI. Bernard University, 69373 LYON Cedex 08 FRANCE. *A. Charial Geriatrics Hospital, 69340 Francheville FRANCE.

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T H E K I N E T I C S O F I N D O C Y A N I N E G R E E N (ICG) IN M A N STUDIED USING AN EXTENDED SAMPLING PERIOD E Burns, PR Jackson, GT Tucker, NDS Bax The elimination of I C G a p p e a r s b i e x p o n e n t i a l w h e n b l o o d s a m p l e s a r e c o l l e c t e d for 60 m i n a f t e r an iv b o l u s d o s e . H o w e v e r , t h e v a l i d i t y of a two compartment kinetic model used with such d a t a to d e r i v e an e s t i m a t e of t h e I C G e x t r a c t i o n ratio and hepatic blood flow has been challenged. Six healthy volunteers gave written informed c o n s e n t to t h e s t u d y w h i c h h a d t h e a p p r o v a l of the local Hospital Ethics Committee. A bolus d o s e of I C G (0.5 m g / k g , iv) w a s g i v e n a n d peripheral b l o o d s a m p l e s c o l l e c t e d f o r up to 48 hrs. The plasma ICG concentration was measured b y H P L C ( a s s a y l i m i t 5 n g / m l ; C V 6%). ICG was measurable for up to i0 h o u r s a f t e r injection. The estimated terminal elimination phase half lives (mean: range) using all data p o i n t s or t h o s e up to 60 m i n o n l y w e r e 823h:260-1,676h and 10h:4-25h respectively. C u r v e f i t t i n g w i t h N O N L I N s u g g e s t e d t h a t in a l l subjects ICG elimination was triexponential rather than biexponential ( p < 0 . 0 1 in 5 c a s e s ) . Curve fitting with ELSFIT gave equivocal results. T h u s t h e u s e of a h i g h l y s e n s i t i v e a n d s p e c i f i c a s s a y a n d an e x t e n d e d s a m p l i n g p e r i o d a l l o w e d the definition of t h e p r o l o n g e d t e r m i n a l p h a s e of I C G e l i m i n a t i o n . F i t t i n g of d a t a o b t a i n e d in t h e f i r s t 60 m i n u t e s to a b i e x p o n e n t i a l function p r o d u c e d an i n a c c u r a t e d e s c r i p t i o n of I C G elimination. T h i s m a y e x p l a i n , a t l e a s t in p a r t , t h e f a i l u r e of a t w o c o m p a r t m e n t pharmacokinetic m o d e l to e s t i m a t e a c c u r a t e l y the hepatic extraction r a t i o of I C G in m a n . U n i v D e p t of P h a r m a c o l o g y and Therapeutics, Royal Hallamshire Hospital, Sheffield, SI0 2JF UK.

ADAPTATIVE AND BAYESIAN CONTROL METHOD OF GENTAMICINE IN DIABETIC PATIENTS. I. Izquierdo, E.L. MariNo*, J. Domenech*, J. Torrent and F. Jane, Feedback control methods have improved dosage optimization of drugs with a narrow therapeutic range, The aim of this work was to estimate gentamicine pharmacokinetic parameters applying the closed-loop control systems criteria. A group of 42 patients suffering type II diabetes, with a mean age of 67.7 13.6 years and a mean weight of 69.2 15.9 kg, received gentamicine (60 to i00 mg/dose) in constant rate infusions of 30 min with dosage interval periods between 8 and 24 h. Blood samples were drawn at steady-state conditions just before drug infusion (trough) at 30 min (peak) and at 3 h post-infusion. Gentamicine plasma levels (Cp) together with creatinine clearance (Clcr) were used for estimating kinetic parameters by means of a bayesian method with adaptative control. Assuming an open monocompartmental kinetic model individual values of distribution volume (Vd), slope (Kslepe) and intersection constants (Kint) were determined. The elimination constant rate (Ke) was calculated according to the following expression: Ke = Kint + Kslope * Clcr. The mean values obtained were: Vd = 0.2637 0.0616 i/kg; Kslope = 0.0038 0.0007 mi/min/h-i and Kint = 0.0070 0o0001 h-l. The Cp calculated (Cp cal) from these parameters was compared (Kruskal-Wallis test) with the experimental data (Cpexp) showing no significant diferences with a good linear correlation: Cp cal = 0.112 0.968 Cp exp (r=0.988;p < 0.000). Feedback control methods are an important clinical research tool which allow to establish correct therapeutic dosing regimes easily in realistic clinical situations. Clinical Pharmacology Unit. Sant Pau Hospital. School of Medicine. U.A.B. Av. S Antoni M Claret 167. 08025Barcelona. Spain. *Galenic Pharmacy Unit. School of Pharmacy. U.B. Barcelona. Spain.

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EXTENDED LEAST SQUARES ANALYSIS OF PHARMACOKINETIC DATA A CAUTIONARY TALE. P. R. Jackson and G. T. Tucker. Extended least squares (ELS) has become widely used for nonlinear regression in the analysis of drug concentration time data. Simulation studies (L.B.Sheiner & S.L. Beal, J.Pharmacokin.Biopharm. 14,185,1985)have been performed suggesting that for unknown variance functions ELS may p e ~ form at least as well if not better than weighted least squares. These simulations have not been repeated for unknown structural models. Using simulation techniques we have studied the behaviour of ELS and weighted least squares (WLS) when the structural model was specified incorrectly. Drug concentration time data were generated from a tri-exponential model and 10% noise was added to produce 100 data sets. The data were then fitted using ELS, WLS weighted by ]/Y and I/Y 2, and ordinary least squares (OLS) using either a tri (TSM) or bioexponentisl (BSM) structural model. To distinguish between the models information criteria (ICs, Akaike, Lennard & Schwarz) were used with ELS and the F ratio with OLS and WLS. WLS with the correct weighting function (I/Y 2) showed a significantly superior fit to the TSM for all cases. WLS weighted I/Y selected the TSM in 55 cases. For ELS the ICs were unanimous in 91 cases and 2 out of 3 criteria agreed in 7 cases in selecting the BSM. OLS failed to distinguish between the fits to TSM and BSM in all cases. All algorithms produced estimates of the terminal elimination rate constant which differed significantly from the true value when using the BSM, but the WLS fit with the correct weighting function was significantly superior to either ELS or WLS weighted I/Y. This limited simulation study suggests that the behaviour of ELS needs further investigation before it becomes a standard method. Determination of the incorrect terminal elimination rate constant may give rise to poor estimates of AUC and is of concern as the ELS principle is used in NONMEM where only limited structural models may be studied. University Department of Pharmacology and Therapeutics, Royal Hallamshire Hospital, Sheffield $I0 2JF, U.K.

THE PHARMACOKINETICS OF A NEW ACE-INHIBITOR SPIEAPRIL AND ITS MAIN METAHOLITE SPIRAPRILATE H.R.Christensen, C.Betz, P.Grass, K.Kufzm J.P.Kampmann Spirapril is a new nonsulfhydryl angiotensin converting enzyme (ACE) inhibitor. Previous studies using 12~5-50 mg have shown an ACE-inhibitory activity decreased to about 50% of baseline values up to 72 hours after spirapril dosing. In small studies the antihypertensive effect has been satisfactory in daily doses from 12.5 to 50 mg. In a randomised crossover study involving 16 healthy volunteers, a linear dose relationship in Cmax and AUC of spirapril and the active metabolite spiraprilate was found after oral doses of 12.5 mg, 25 mg, 50 mg and 75 mg, respectively. The absorption and elimination kinetics of spirapril and spiraprilate did not change with dose. The elimination of spirapril was uniphasic with an average half-life of 0.9 (SD 0,2) hours. The elimination of spiraprilate was biphasic with half-lives of 1.5 (SD 0.3) hours and of 20 hours or more (sampling only up to 28 hours). In a trial assessing variability, 18 healthy young volunteers received three single oral administrations of 25 mg spirapril. Blood was sampled up to 12 hours. The coefficient of variation of tmax, Cmex, AUC, rate constant and lag-time were in the order of 30-50% for spirapril and 15-30% for spiraprilate. For spirapril V d was estimated to 75 (SD 25) litre and clearance to 55 (SD 23) litre/h, half-life about i h. For spiraprilate only the alpha half-life could be estimated, 0.95 (SD 0.15) hours, due to the short sampling period. In both studies we found a quick absorption, tmax for spirapril 0.65 hour, and for spiraprilate 1.8 hour. The drug was well tolerated by the volunteers. Eispebjerg University Hospital, Medical Dept. P, Bispebjerg Bakke 23, DK-2400 Copenhagen NV, Denmark. Dept. Human Pharmacol. Sandoz Ltd., Basle, Switzerland

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PHARMACOKINETICS OF MOLSIDOMINE AND SIN-I IN HEALTHY VOLUNTEERS, ELDERLY PATIENTS AND CORBNARY PATIENTS. O.Varoquaux~P.Cordonnier,C.OutotTB.Ulmer,R.Beaufils~C. Duereuzet,C.Advenier~M.Pays. SIN-I, linsidomine, is an active metabelite of the prodrug molsidomine (MSD). By IV infusion, SIN-1 was shown to be s potent coronary vesodilator. This work defines the simultaneous plasma determination of MSD and SIN-I after administration of MSD or SIN-1 in clinical studies. The separation of the 5-alkoxycarbonyle derivatives were carried out by an HPLC-RP method (column Beckman Ultrasphere IP 5pm, mobile phase:acetenitrile-aqueous O.OiM potassium dihydregen phosphate 18-22 v/v, detection UV-312nm). Retention times were 6.4mn for MSD, ll.8mn for propylSIN-i and B.4mn for the internal standard. The limits of detection were 0.5 and O.4ng/ml for MSD and SIN-1 respectively. Plasma pharmacokinetic parameters in six young healthy volunteers (25.5• years) and six elderly patients (81.I• years) given a 2mg oral single dose of MSD were studied. In the elderly group, the half-life of MSD (1.9• vs 1.2• and the apparent half-life of 51N-1 (1.8• vs 1.O• were slightly increased (p
I"HE EXCREI'JION Of: I
1.h-l)

was

decreased

(p
The

differences

have

however no implication in repeated administration according to the short half-life values. A second phsrmscokinstic study was performed in six coronary patients(52• years) receiving a img IV single dose of SIN-1. The half-life of SIN-1 was 29.5• Vd 0.64• 1.kg-i and the elimination clearance 1.25• l.mn-l). Tolerance was satisfactory, especially neither headheache, nor hypotension occured during the assay. T h i s determination allowed to elaborate an IV infusion protocol for SIN-1 administration end to insure a good SIN-I monitoring in coronary disease treatment. Centre Hospitalier de Versailles,7B150 Le Chesnay,France

Ketorolac tromethamine (KT) is an analgesic which has been shown to be e f f e c t i v e in r e l i e v i n g post partum pain. ]he o b j e c t i v e of: t h i s study was to e s t a b l i s h the extent of any excr'etion o f KT into breast miU~, and hence the p o t e n t i a l dose to the i n f a n t . KT a d m i n i s t r a t i o n was started between 2 and 6 days a f t e r

d e l i v e r y , to ten mothers who would not be feeding breast milk to t h e i r babies, e i t h e r due to a n t i b i o t i c use or neonatal jaundice. 10 mg KT was administered o r a l l y 4 times d a i l y f o r 2 days. Milk samples were collected on both dosing days and on the f i r s t post-dosing day. Plasma samples were L~ithdrawn concurrently. Samples were assayed l~or ketorolac concentrations by HPLC. In 4 patients the concentration of ketorolac in the milk was never" above the q u a n t i t a t i o n level of: 5 ng/ml. In the other 6 patients 2h post.dosing on both days i and 2 there were q u a n t i f i a b l e concentrations o f ketorolac in the milk. The range was 5.2 ng/ml - 7.9 ng/ml. The materr~al plasma concentrations were w i t h i n the expected ranges For KT, i n d i c a t i n g that l a c t a t i o n does not el:fact ti~e metabol~sm of KI. The p o t e n t i a l dose of KT to an irritant would range from 3.2}/g to 7,gyug per day assuming a mJfk consumption of between 400 ml and ii of breast milk. Klinikum der Stadt Mannheim, Gynaecological C l i n i c , Mannheim, West Germany.

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MULTIPLE-DOSE PHARMACOKINETICS OF NICORANDIL. PRELIMINARY EVALUATION OF A TIME-VARYING PHARMACOKINETIC MODEL R. Bruno, A. Frydman, A. l l i a d i s , G. Montay, E. Roland, J.J. Th4bault, J. G a i l l o t (Rh6ne-Poulenc Sant6, Antony; Facult6 de Pharmacie, M a r s e i l l e ; IREB, Paris, France) The multiple-dose pharmacokinetics of the new antianginal drug n i c o r a n d i l has been evaluated in 12 healthy volunteers f o l l o w i n g administration o f 10 and 20 mg b . i . d , f o r 10 days in an open study with two treatment phases and a two-month washout period. Plasma l e v e l s of n i c o r a n d i l were measured b y a very s e n s i t i v e GC-MS m e t h o d ( 0 . i ng/ml) in plasma samples drawn on days i , 3, 5, 7 and I0. Single-dose pharmacokinetics are consistent with those p r e v i o u s l y observed i . e . rapid absorption (tma x : 0,5 h), d o s e - l i n e a r i t y (Cmax, AUC) and biphasic e l i m i n a t i o n p r o f i l e with a rapid phase ( t i / 2 : I h) which concerns more than 90 % of the t o t a l value of AUC and a f u r t h e r phase of sustained very low l e v e l s (0.5 to 2.5 ng/ml) noised with rebounds, not consistent with exponential models. Following b . i . d , dosing, AUC (0-12 h) s i g n i f i c a n t l y increased from day I to I0 ( r : 1.7 + 0.6 and 2.0 + 0.8 f o l l o w i n g i0 and ZO mg b . i . d , r e s p e c t i v e l y ) . The washout e l i m i n a t i o n p r o f i l e , s i m i l a r to that observed f o l l o w i n g the i s t dose presented rebounds 10-12 h, 20-24 h and 48 h post-dose. Moreover the 8 a.m. predrug l e v e l s were s i g n i f i c a n t l y higher than the 8 p.m. ones. To account f o r these p e c u l i a r i t i e s we developped a two-compartment model with a time-varying (sinusoidal function) d i s t r i b u t i o n rate constant (k21). The data were well f i t t e d using a 24 hours period (circadian rhythm) with a 43 % amplitude o f v a r i a t i o n . A preliminary evaluation o f the main features o f the model and a discussion of the underlying b i o l o g i c a l assumptions w i l l be presented. Rh6ne Poulenc Sant6 - IBP - 20, Avenue R. Aron F-92165 Antony Cedex, France.

P H A R M A C O K I N E T I C S OF M O C L O B E M I D E (M) IN BREAST MILK AND PLASMA AFTER ORAL D O S I N G M.P. Schoerlin, G. Pens, Y.E. Tam, C. Moran, J.P. Pfefen, Ch. Frencoual, A.M. P~darriesse, G. Olive single oral dose (300 mg) of m o o l o b e m i d e (M) was given to 6 h e a l t h y lactating mothers (age: 24-36 yr; weight: 48-63 kg) b e t w e e n the 2nd and 5th day post delivery. Blood and milk samples were collected at appropriate time intervals over a 24-hour period after drug administration. M, its active metabolite (Re 12-5637) end its major metabolite in plasma (Re 12-8095) were m e a s u r e d in these samples using a p r e v i o u s l y described HPLC method. The excretion rates (mean • SD) of M (36.8 • 5.8 pg/h) and Re 12-8095 (15.5 • 2.2 pg/h) into breast milk were h i g h e s t during the first three hours after M a d m i n i s t r a t i o n and the excretion was complete w i t h i n 12 h. The active m e t a b o l i t e could not be q u a n t i f i e d in the milk samples. The % of dose excreted as M end Re 12-8095 were 0.057 • 0.021 and 0.031 • 0.011%, respectively. With a mean body w e i g h t of 4 kg, a n e w b o r n b a b y w o u l d receive an average of 38 pg/kg of M which is equivalent to less than 1% of the adult dose. The p l a s m a kinetics of M in these lactating women were similar to those seen in previously reported studies involving h e a l t h y male and female subjects. The m a x i m u m M concentration, the time to achieve this value, and the elimination half-life were 2.7 • 1.24 pg/ml, 2.03 • 1.20 h end 2.3 • 0.27 h, respectively. In conclusion, the insignificant amount of M excreted into b r e a s t milk is u n l i k e l y to be hazardous to suckling infants. F. H o f f m a n n - L a Roche & Co. Ltd., Dept. of Clinical Pharmacology, CN - 4002 Basel (switzerland)

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BENAZEPRIL AND BENAZEPRILAT IN HUMAN PLASMA AND BREAST MILK G. Kaiser1, R. Ackermann 1. W. Dieterle 1 and P.M. Fleiss 2 Benazepril hydrochloride (BH), through its active meta bol i t e benazeprilat (BT), is a potent, long acting, nonsulfhydryl ACE inhibitor. BH 20 mg once-daily was administered perorally to nine normotensive lactating women on three consecutive days. Unchanged benazepril (B) and the metabolite BT were determined in plasma and breast milk by gas chromatography-mass spectrometry. Extremely small concentrations of B and BT were detected in milk. The elimination of B from plasma and its excretion in milk were almost complete after 4 to 6 h whereas BT was still detectable in plasma and milk at 24 h after dosing. Peak plasma concentrations (-+ SD) of B and BT afte r the last dose averaged 862 • 412 and 1614 • 496 pmol/g, respectively, as compared to average peak milk concentrations of 2.0 • 1.1 and 4.6 -+ 1.9 pmol/g, respectively. The mean milk/plasma ratios derived from individual values of the pharmacokinetic parameters were 0.003 for Cmax of both B and BT, 0.011 for AUC of B and 0.010 for AUC of BT. The time to Cmax of both B and BT was about 3-times longer in milk than in plasma where median values of 1 h for B and 1.5 h for BT were observed. The r e l a t i v e dose of B which may be ingested by a breastfeeding infant is certainly less than 0.04 % of the m a t e r nal dose. The corresponding amount of the metabolite benazeprilat t h a t the infant may receive from milk should be in the order of 0 . 1 % of the maternal benazepril.HCl dose. However, since benazeprilat is expected to be poorly absorbed the fraction of BT reaching the systemic circulation of the infant should be negligible. Conclusively, benazepril hydrochloride seems to be a drug that may be safely administered in lactating hypertensive patients in the usual therapeutic doses. 1Research and Development Department, Pharmaceuticals Division, CIBA-GEIGY Ltd., CH-4002 Basle, Switzerland 2Hillhurst Avenue, Los Angeles, CA 90027, USA

MATERNAL/FOETAL PROPOFOL LEVELS AT DELIVERY FOLLOWING PROPOFOL INFUSION ANAESTHESIA FOR CAESARIAN SECTION M.A.Gregory, T.Gin , G.Yau, K.Chan & T.E.Oh Propofol is a new intravenous induction agent that has been widely used as an infusion for general surgical anaesthesia, but has not yet been used in obstetric anaesthesia. Ten healthy Chinese women scheduled for elective caesarian section were studied. After a period of preoxygenation, anaesthesia was induced with a bolus dose of 2.0 mg/kg of propofol, and an infusion (9 mg/kg/hour) was started. The trachea was intubated following suxamethonium 1.5 mg/kg and each woman was ventilated with 100% 02 to an end-tidal COp of 4.0-4.5%. Atracurium 0.5 mg/kg was used for continued muscle relaxation. At delivery maternal venous (MV) blood and umbilical arterial (UA) and umbilical venous (UV) blood was taken for analysis. Propofol in whole blood was assayed using liquid chromatography and fluorometric detection. The induction-delivery times ranged from 8.5-16 minutes. MV propofol levels ranged from 2.08-3.58 ~g/ml (mean:2.72, standard error (se)=0.16), umbilical venous (UV) ranged from 1.01-I~90 ~g/ml (mean=1.51,se=0.97) and UA ranged from 0.58-1.06 ~g/ml. (mean=0.89, se=0.06). UV/MV ratios ranged from 0.37-0.79 (mean=0.55, se=0.05, n:9) UA/UV ratios ranged from 0.50-0.68 (mean=0.57, se=0.03, n=9). The mean UV/MV ratio is less than that reported for thiopentone and ketamine. The mean UA/UV ratio of 0.57 shows that significant foetal uptake is still occuring. The 1-& 5-minute Apgar scores were all satisfactory. Departments of Anaesthesia and Intensive Care & Pharmacology, Prince of Wales Hospital, The Chinese University of Hong Keng, Shatin, Hong Kong.

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MATERNAL - FETAL RATIOS OF PROPOFOL AT CAESAREAN SECTION T.Gin, M.A.Gregory, K, Chan, T.Buckley, T.E.Oh Propofol is a new anaesthetic agent which has been used for induction and maintenance of anaesthesia. Experience in obstetric anaesthesia is limited and there is no information on placental transfer in the first 15 minutes of anaesthesia when maternal levels are high. Twenty healthy Chinese women undergoing elective Caesarian section were studied. After preoxygenation, propofol 2mg/kg was given over 20 seconds followed by suxamethonium 1.5mg/kg. After intubation, anaesthesia was maintained with 50% nitrous oxide in oxygen and 1.0% enflurane. Atracurium 0.3mg/kg was given for muscle relaxation and ventilation was controlled to maintain end-tidal carbon dioxide levels of 4.0 kPa. At delivery, maternal, umbilical arterial and umbilical venous blood was obtained for analysis. Propofol in whole blood was assayed by liquid chromatography with fluorometric detection. The induction delivery times ranged from 5 to 14 minutes. At delivery, the maternal venous (MV) concentrations of propofol were 0.58-1.48 ~g/ml; umbilical vein (UV) 0.391.4 mg/ml and umbilical artery (UA) 0.34-0.68 ~g/ml. MV and UV levels were related to each other (Linear Regression:UV=O.55MV+61,r=O.58,p
PHARMACOKINETICS OF BENAZEPRILAT AFTER INTRAVENOUS ADMINISTRA~TION IN HEALTHY VOLUNTEERS W. Dieterle. R. Ackermann and G. Kai~gr The new nonsulfhydryl ACE inhibitor benazepril hydrochloride (BH) is a prodrug designed for oral administration. BH is efficacious in the t r e a t m e n t of hypertension (M.E. Hurley e t al., J. Clin. Pharmacol. 27, 718, 1987) and has shown beneficial effects in congestive heart failure patients (J. Insel e t al., Clin. Res. 36, 32A, 1988). Upon absorption, BH is rapidly and extensively metabolized to its pharmacologically a c t i ve principle, the dicarboxylic acid benazeprilat (BT). The pharmacokinetlcs of BT were now evaluated in 12 healthy volunteers after a 5-rain intravenous infusion of 20 mg BT. BT was determined in plasma and urine by gas chromatography-mass spectrometry. The plasma concentrations of BT declined in a polyphasic manner. The main phase between 2 and 24 hours showed a half-life - determined by the method of residuals - of 3.0 • 0.4 h (mean • SD). The prolonged terminal elimination phase (48-72 h) was characterized by concentrations less than one thousandth of the maximum concentration and a mean half-life of 26.4 -+ 8.3 h. In a model independent approach, the volume of distribution a t s t e a d y - s t a t e was calculated to 8.7 • 2.2 1. The urinary recovery of BT within 72 h was 84.1 • 5.9 % of the dose. Total clearance of BT was 29.9 • 7.3 ml/min and renal clearance 25.6 -+ 7.3 ml/min. Alkaline hydrolysis of the glucuronide conjugate of BT in urine and measurement of total BT resulted in a small increase of the urinary recovery to 88.6 • 4.6 % of the dose. Thus, direct glucuronidation of BT is of minor importance after i.v. dosing of BT. This is in contrast to the distinct glucuronidation of BT after p.o. dosing of BH. Conclusively, the pharmacokinetic parameters indicate th at in healthy man BT is not distributed extensively into extravascular sites and is mainly eliminated from the body by the renal route. Research and Development Department, Pharmaceuticals Division, CIBA-GEIGY Ltd., CH-4002 Basle, Switzerland

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PHARMACOKINETICS AFTER INTRAVENOUS INFUSION OF DILTIAZEM, N-DEMETHYLDILTIAZEM AND DEACETYLDILTIAZEM P. HBOlund, T. FAhraeus and K.-E. Andersson The metabolic steps for diltiazem include N-demethylation and deacetylation. In this study 30 healthy volunteers were given 20 mg of e i t h e r diltiazem (DZ), N-demethyldiltiazem (MA) or deacetyldiltiazem (MI) as an intravenous infusion during 20 minutes. DZ and metabolites were assessed using HPLC. Standard pharmacokinetic methods were used. Results Unit Drug Mean 95% confidence int t89 h DZ 2.86 2.01 3.71 MA 5.08 4.28 5.89 MI 2.87 2.02 3.72 MRT h DZ 3.67 2.54 4.81 MA 6.80 5.73 ' 7.88 MI 3.41 2.28 4.55 AUC nmol'h'1-1 DZ 738 663 813 MA 398 327 469 MI 669 594 744 CL ml'min-l'kg - 1 D Z 15.8 12.4 19.2 MA 32.8 29.6 36.0 M1 21.4 18.0 24.8 Vc l ' k g -1 DZ 1.02 0.19 1.86 MA 2.19 1.40 2.99 M1 1.17 0.33 2.00 Vss l'kg -I DZ 3.46 1.57 5.35 MA 13.00 11.20 14.80 MI 4.21 2.31 6.10 Varea l'kg -I DZ 3.89 2.04 5.74 MA 14.06 12.30 15.81 MI 5.05 3.20 6.90 There were only minor k i n e t i c differences between DZ and M1 a f t e r a single intravenous dose. The h a l f - l i f e and MRT of MA were longer and AUC, CL and the volumes of d i s t r i b u t i o n were l a r g e r ( a l l p <0.01) than the corresponding values f o r DZ and MI. Department of C l i n i c a l Pharmacology, L u n d U n i v e r s i t y Hospital, S-221 85 LUND, Sweden.

S T E A D Y S T A T E P H A R M A C O K I N E T I C S OF N I L V A D I P I N E SLOW-RELEASE PELLET FORMULATION

A. Mionot, M.A. Lefebvre, Ph. Patsy, M.J. Douin (1] J.J. Thebault, H. Caplain (2] H.J. Huber, Ch. Moser, A.v. Nieciecki, F. Stanislaus (3) Healthy male volunteers [n=24), with a mean age of 24 + 3 years were given once daily 8 mg nilvadipine solution [SOL} or slow-release pellet formulation (S.R.) for 8 days in a two-way cross-over design. A f t e r a drug free interval of 8 weeks, twelve o f these volunteers were given once daily doses of 16 mg S.R. for 8 days. Plasma kinetic profiles were evaluated after the f i r s t and the last dose of each period. Nilvad_i~oine reached Cmax 11.07 + 5,55 ng.ml - I and 2.25 + 1.08 ng.ml --after 0.70 +_ 0.22 h and 2.07 + 1.03 h for the 8 mg single dose SOL and S.R., respectively. The mean dissolution time (MDT) of S.R. was 2.46 + 1,09 h, indicating efficient retardation. Following multiple dose administration [MD] of 8 or 16 mg nilvadipine S.R. no accumulation of Cmax and AUC could be seen: Cmax-ratios (I,21 + 0.85 and 1.18 + 0.70) and AUC 0-z" ratios after single and multiple dose {I.07-+ 0.52 and 1,03 + 0,47) were not significantly different. Cmin increased by a facto} of 1.58 on average {range 0.85 - 4.23). MRTss was 11.06 + 3.26 h and 9.52 * 2,39 h after 8 and 16 mg S.R., respectively.The T89 Xz of 8 mg SOL (Iog-lin.reg.) was 6.67 + 1.18 h a f t e r single and 18.18 + 6.13 h after multiple dosing,-which corresponded welt with the model-independent effective T89 of accumulation (T89 = 17.96 hi. Duration of headache, per subject for 8 days, was less with S,R. (2.8 h] than with SOL [10.4 h). In conclusion, nHvadipine kinetics are not time dependent (AUC and Cmax]. The prolonged T89 and accumulation of Cmin detected a f t e r MD are likely to be a result of slow transfer from peripheral [tissue) compartment[s) to the central compartment. Markedly decreased side effects after S.R. can be regarded as benefit f o r patients. [1] CEPHAC, 13P 28, 86280 St. Benoit, France. (2] ASTER, HSpital Cognacq-Jay, 15 rue Eug6ne Millon, 75015 Paris, France (3] KLINGE PHARMA, Weihenstephanerstr. 28, 8000 MCinchen 80

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RO 40-5967: P H A R M A C O K I N E T I C S OF A N E W C A L C I U M A N T A G O N I S T H. A. Welker, H. Eggers, C. Kleinbloesem, K. Erb, K. Breithaupt, R. Butzer, and G. G. Belz Ro 40-5967 is a new c a l c i u m a n t a g o n i s t p r e s e n t l y u n d e r clinical d e v e l o p m e n t as an a n t i s n g i n a l and a n t i h y p e r t e n sive agent. In a n i m a l e x p e r i m e n t s a long d u r a t i o n of action, a high b i o a v a i l a b i l i t y , and a h i g h d e g r e e of cardiac s e l e c t i v i t y w i t h o u t n e g a t i v e i n o t r o p i c p r o p e r t i e s had been d e m o n s t r a t e d . Human p h a r m a c o k i n e t i c s were i n v e s t i g a t e d f o l l o w i n g single a s c e n d i n g oral and i n t r a v e n o u s doses in a d o u b l e - b l i n d , r a n d o m i z e d t w o - w a y c r o s s - o v e r study in h e a l t h y m a l e volunteers. The a d m i n i s t e r e d doses i n c r e a s e d from i0 to 320 mg (oral) and from 2.5 to 80 mg (iv). Blood samples were a p p r o p r i a t e l y c o l l e c t e d and p l a s m a was a n a l y s e d for u n c h a n g e d RO 40-5967 by means of a HPLC s y s t e m w i t h f l u o r e s c e n c e detection. After i n t r a v e n o u s administration, plasma c o n c e n t r a t i o n s d e c l i n e d in a b i p h a s i c m e n n e r w i t h h a l f - l i v e s of ~ 6 hours (distribution) and ~ 13 hours (elimination). The volume of d i s t r i b u t i o n (Vss) ranged from 190 to 220 liter, the systemic c l e a r a n c e v a r i e d b e t w e e n 260 and 350 ml/min, both p a r a m e t e r s i n d e p e n d e n t of the dose. After oral a d m i n i s t r a t i o n , Ro 4 0 - 5 9 6 7 showed a r a p i d absorption, Cma x was m o s t l y reached within 1 hour. The e l i m i n a t i o n h a l f - l i f e w i t h 12 to 14 hours was similar te that after iv a d m i n i s t r a t i o n , but tended to be longer w i t h h i g h e r doses (>160 mg). The b i o a v a i l a b i l i t y of Ro 40-5967 inc r e a s e d with i n c r e a s i n g doses p o s s i b l y due to a s a t u r a t i o n of the m e t a b o l i c enzymes in the liver. F. H o f f m a n n - L a Roche & Co. Ltd., D e p a r t m e n t of Clinical Research, CH-4002 Basel, S w i t z e r l a n d

A POTENTIAL ENTEROHEPATIC CIRCULATION OF B-METHYLDICA)XIN IN HUMAN SUBJECTS H. Nakashima, K. Tsutsumi. M. Hashiguchi. A. Ebiham. H. Hirooka*, K. Havashi* Beta-methytdigoxin (B-ME)) is a cardiac glycoside used for the treatment of heart failure and arrhythmia. B-MD is mainly metabolized to digoxin (D3), digoxigenin bisdigitoxoside, digoxigenln monodigitoxoside and digoxigenin. We have developed a new method to determine B-MD and its metabolites in serum and urine by a HPLC and a fluorescence polarization immunoassay. Serum concentrations of B-MD and its metabolites were followed for 144 hours after single oral administration of B-MD (0.2 rag), and pharmacokinetic characteristics were evaluated in seven Japanese healthy volunteers. Only B-MD and D3 were detected in serum. The peak serum concentrations of B-MD and D3 were 1.87 • 0.70 (mean _+ S.D.) ng/m] at 0.71 • 0.30 hr and 0.28 • 0.06 ng/ml at 1.11 • 0.28 hr, respectively. The pharmacokinetic parameters of B-MD were evaluated by a two-compartment open model using NONLIN. The elimination half-life and the steady-state volume of distribution of B-MD were found to be 51.1 • 12.9 hr and 10.2 • 2.0 lag, respectively. One or two small peaks other than maximal peak was observed in the individual time-concentration curves of B-MD. These data suggested that ]]-MD has a enterohepafic circulation in human subjects. Department of Clinical Pharmacology, Medical College of Oita, 1-1506, Idaigaoka, Hazama-cho, Oita-gun, Oita-ken 879-56, Japan *Yamanouchi Pharmaceutical Co., Ltd., 108, Azusawa 1 chome, Itabashi-ku, Tokyo 174, Japan

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PHARMACOKINETICS OF 5-HYDROXY-PROPAFENONE IN HUMANS H. R. Ha~ W. Haefeli~ S. Vozeh and F. Follath 5-hydroxypropafenone (5-OHP) is the major metabolite of propafenone (P) which appears to contribute to the therapeutic effect of the parent compound. Having developed a new sensitive and specific HPLC method for the measurement of 5-OHP and its metab01ite 5-hydroxy-methoxypropafenone (5-OHMP) in serum and urine, we applied it to the evaluation of the pharmacokinetics of 5-OHP following a single dose in 6 healthy volunteers. After administration of 300 mg 5-OHP dissolved in 200 ml water, the drug was rapidly absorbed and distributed. A Cma x of 253• ng/ml was reached after 35.5• min (tmax). The half-life was 259• min (t89 of P 149• min), the oral clearance 30• ml-min-l'kg -I. The AUC o of 5-oHP in serum varied interindividually: 29'522• ng'min'ml -I (CV = 40.5%). We found only 0.65• of dose as unchanged drug in the urine. The metabolite 5-OHMP was under the limit of detection (2 ng/ml) in serum and its elimination by renal route amounted to 0.05• of dose after 24 hours. However, after enzymatic cleavage with 8-glucuronidase and aryisuifatase, 13.2% and 2.9% of the dose were recovered in the urine in form of 5-OHP and 5-OHMP, respectively. Further studies in patients are necessary to elucidate the clinical importance of 5-OHP.

SINGLE AND MULTIPLE DOSE PHARMACOKINETICS OF TROSPECTOMYCIN SULPHATE, A NOVEL AMINOCYCLITOL ANTIBIOTIC, IN HEALTHY VOLUNTEERS.

Division of Clinical Pharmacology, Department of Medicine, University Hospital (Kantonsspital), CH-4031 Basel, Switzerland

DJ.Nichols, A.Bye, G.R.Peters and E.Novak Trospectomycin sulphate, an analogue of spectlnomyci.n, has goo.d_in vitro activity against a broad spectrum of both gram positive an--fi-ff-gramnegative aerobic andanaerobic bacterm, as well as against Chlamvdia trachomatis and is 10 times more potent than spectinomycin. The pharmacokinetics of trospectomycm sulphate were examined by measurement of drug concentration in serum in 170 male, healthy volunteers, who received a single 20 mix IV infusion, or a single IM injection over the dose range of 75-1000 mg; or multiple IM injections for 789 consecutive days (two times daily) in doses of 300, 600 or I000 rag; or 21 multiple IV infusions (30 minutes three times daily) for 7 consecutive days in doses of 250, 500 or 750 rag. The concentration in s e r u m (expressed in free base equivalents), measured using a sensitive HPLC technique, was <.2~g/mt by 12 hours after dosing at all dose levels. The disappearance of trospectomycin f r o m serum was biphasic with half lives of 1-2 h and >15 h. AUC and Cmax were linearly related to dose" AUC (~tg/ml.h~-0.15*Dose(mg), Cmax(IV)~tg/ml-0.06*Dose(mg) and Cmax(IM),ug/ml-0.03*Dose (rag). The concentrations in serum were fitted to two and three compartment models. These indicated that the drug distributed initially into extracellular space (V~ 17-35% body weight) and subsequently into tissues (Vss 59-I 12~ body weight), The drug was eliminated rapidly (MRT 6 - t I h), and without significant metabolism, via urine (>40%dose by 8 h) but a proportion appeared to be retained by tissues as indicated by a slow mean transit time (18-43 h) in the tissue compartment. The clearance rate Was 110-t50 ml/min; within the normal range for GFR. Simulations, using the single dose kinetic parameters, predicted the multiple dose serum concentrations except for a small dose and rime related increase in Cmax and A U C seen in subjects dosed IM. This was consistent with the absorption rate increasing as the dosage regime progresses. Simulations also indicatedthat significant .accumulation in tissues would occur with an 8 hour dose mterval. Pharmaceutical Research Laboratory, Up john Ltd, Fleming Way, Crawley, Sussex, UK.

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CLINICAL PHARMACOKINETIC STUDY ON NETILMICIN AND ITS SERUM MONITORING OF EIA AND RIA. I. Nakayama, Y. Akieda and E. Yamaii Netilmicin is a broad spectrum aminoglycoside antibiotic which is currently of great value in the treatment of severe infections. Its ant• spectrum is very similar to that of other aminoglycosides while its intrinsic toxicity is reported as somewhat lower. Optim1:~ therapeutic concentration in human serum lies between 4 and 12 Dg/ml for netilmicin. Below this range netilmicin is ineffective, however higher concentrations may lead to ototoxicity and nephrotoxicity. Therefore, it is important to monitor the serum concentration of the aminoglycoside antibiotic in order to avoid these adverse reactions. The procedure was investigated using an EIA kit for AMES TDM netilmicin and a RIA Kit manufactured by MONITOR SCIENCE. When a single dose of 75 mg or 100 mg of netilmioin was given intramuscularly to each of three healthy volunteers, the peak serum levels attained were 7.1 ~g/ml (for 75 mg) and 9.27 pg/ml (for 100 mg) for EiA and 6.93 ~g/ml and 8.67 ~g/mi for 2IA after I/2 hour. The measurable concentration persisted to show averages of 0.55 ~g/ml and 1.42 Dg/ml for EIA and 0.5 ~g/ml and 1.03 ~g/ml for RIA 6 hours after administration. A pharmacokinetic study was carried out by use of a one compartment method. Pharmacokinetic parameters showed that the half life (~) was 1.3 - 2.0 hours. AUC were 13.2 - 14.2 ~g h/ml for 75 mg and 20.61 - 23.80 ~g h/ml for 100 mg respectively. The maximum urinary excretions were 363.3 ug/ml (EIA) or 377.3 ~g/ml (RIA) for a dose of I00 mg one hour after administration. Of these doses given 73 - 75.6% for 75 mg and 78.2 - 80.6% for 100mg were recovered within 6hours from urine samples. Analysis of urine by TLC and Bioautography revealed that there were no biologically active metabolite of netilmicin. EIA and RIA are homogenous, rapid, sensitive and applicable to total clinical automation.

THE PHARMACOKINETICS OF LINCOMYCIN IN HEALTHY VOLUNTEERS M.A.Young, C.A,James and A.Bye. Lincomycin, an antibiotic isolated from a soil Streptomycete is indicated for serious infections (Mason et al, in Antlmicrobiat Agents and Chemotherapy. pp554-559 196"2). The pharmacoklnet,cs and bioavailabitity of a new, single site, l.m. injection given once daily as a 12G0mg dose (600mg/ml) formulation of lincomycin (.A) were compared wim the established 300mg/ml formulation given as a 1200mg dose at two sites (B); ana a 600mg single site dose given b.i.d. (C) in 18 healthy volunteers. PIasma samples were collected over 36 h, urines over 72 h, and subjected to HPLC analysis. These data were consistent with a single compartment m o d e l with first order absorption and elimmatlon. Following treatment, the AUCs (w~thin the first 12h from dosing) were not dose proportional (69.57• (C) compared to 105.23• (B) and 96.97!'22.23,uB/ml/hr (A)). The reason for this nonproportionality was thought to he due to saturable protein binding and associated changes in total body clearance of lincomycin (Gwilt and Smitht J.Clin.Pharmacol. 26 79-86 1986). The amount eliminated m the urine in the 0-12 hour period for the 600rag dose was 0.45 that of the 1200rag dose (173.1• (C) compared to 386.2+-99.5mg (B)). The time to peak concentration was significantly longer for the new single site administration A .(4.47• compared to the established formulation B (1.03+1.74h). The plasma concentrations were above the MIC value of l/~g/mt for 24-30 hours. The likely plasma concentration time profiles were simulated for multiple dosing with the established doses using a one compartment model with the 600rag single dose formulation giving least fluctuation in plasma concentration w~th no accumulation in either case. The new formulation was judged not to be bioequivalent with the established formulation. Pharmaceutical Research Laboratory, Upiohn Ltd, Way, Crawley, West Sussex, England. RHIO 2NJ.

Fleming

A 306

PP 14.26

PP 14.28

PHAR~4ACOKINETICS A N D TOLERANCE

PHARHACOKINETIC5 AND BZOAVAILABILITY OF 73410 ORAL PREPARATIONS OF CIPROFLOXACIN I N YOUNG HEALTHY VOLUNTEERS

OF S E R T A C O N A Z O L E C R E A M Farr~ M. U ~ n a B. Badenas JM. M~r~uez M*. Ortlz JA*. Sertaconazole (SER) is a new imidazole derivative with antifungal activity (Eur J Med Chem 1986; 21: 329) recently developed by Ferrer Research Center (Barcelona, Spain). A elinical trial was carried out to assess the t o l e r a n c e and p h a r m a c o k i n e t i c s of SER a d m i n i s t e r e d topically on the skin. Methods Bigth healthy male volunteers participated in the trial. Tolerance was studied after the topical application of SER 2 % cream twice a day during 14 days in a increasing dose schedule (total dose = 1.96 g). Blood and urine analysis were done during and after the trial. Topical pharmacokinetics was assesed in two ways: a) After a 16 g single dose of SER 2 % cream on the back of the subjects. The c r e a m was rubbed in until disappeared. Blood and urine samples were collected at 0, i, 2, 4, 6, 8, 12 and 24 h. b) Treating eigth 3 cm square areas of the ventral forearm skin with 0.1 g of SER 2 % cream, that were uniformly applied over the areas and rubbed in for one minute. The areas were washed with ethanol at different times from 0 to 24 hours. SEK in serum, urine and washing liquid were analyzed by HPLC with UV detection, being the sensitivity limit 25 ng/ml. Results No changes from baseline were found in the skin treated areas or in the b l o o d and urine analysis performed. After 16 g cream single dose application, SER levels in plasma and urine were not detected. The mean accumulative absorbtion rate, expressed as a percentage of dose administered was 72 %. After its topical administration on the skin, sertaconazole was well tolerated and had a percutaneous absorbtien similar to o t h e r imidazele antifungal derivatives. Dept Pharmacol, Inst Mun Inv Med (IMIM) , P. Maritim 25, 08003 Barcelona, Spain. * Ferrer Research Center.

B.Miljkov~d,M.Pokrajac,H.Prostran and L . g l i ~ o v i d CiDroFloxacin i s a new, Detent a n t i b a c t e r i a l drug From the group os 6-s 5ingle dose pharmacok~netics and b i o a v a i l a b i l i t y o f two oral preparations ( t a b l e t s ) of clpros wete investigated in group of eight young healthy volunteers of both sexes. Homogenous group of the subjects consisted of 5 male and 5 Female, aged between 22 and 51 years (26.6 ~ 2.4, mean ~ 5D), and of body mass between 56 and 75 kg (65.7 ~ 6.7). The drug was qiven as a slngle oral dose of 500 mg, and concentrations o f c i p r o f l o x a c i n Zn ~lasma were Followed d u r i n g i 2 h period, ClpreFloxacin concentrations i n plasma were determined by the method of high performance l i q u i d chromatography (HPLC). ~ period os seven days an l n t e r v a l between administration of the two pteparations. Plasma concentFations decline a f t e r oral administration os ciproFloxacZn was consistent with an eden two-compartment pharmacoklnetic model. Naln pharmaeoklnetic oarameters ( t l a g Cmax tmax t l / 2 and AUC) were calculated and s t a t i s t i c a l l y compared between the two preparations. There was s i g n i f i c a n t difference neither i n plasma concentrations p r o f i l e nor i n pharmacokinetic parameters calculated f o r both the arepaFations investigated. That was a good example of b i o l o g i c a l equivalence of two o r s ! ereparatiens of c i p r o f l o x a c l n From two dls163 manufacturers. Department of Pharmacology and Pharmacokinetlc5, Faculty of Pharmacy, P.O.Box 146, 11000 Belgrade, Yugoslavia

PP 14.27

PP 14.29

DIFFUSION OF CLOXACILLIN IN SYNOVIA H. Mattie, S. De Marie, G. Slaghuis, and P.M. Rozing Clo~acillin is used in the prophylaxis of peroperative infections during implantation of foreign material in joints. To establish the optimal time of administration the rate of diffusion of eloxacillin into the joint and vice versa should be known. For this ii patients were studied who underwent elective hip s u r g e r y f o r arthrosis and who received cloKacillin and kanamycin as prophylaKis. In all patients 1 g of cloKacillin was administered by a continuous infusion of 30 min duration. When the capsula was being opened a sYnovis sample was taken. Blood samples were taken from the start of the infusion to some time after sampling the synovia. Concentrations in plasma and synovial tissue (after e~trsction) were measured by HPLC. Rate constants of diffusion were calculated on the basis of the equation dC /dt=k C -kTCT, in which T p C m is the tissue concentration, C t~e plasma concentration and k and kT rate constants of the diffusion of eloKacilli~ from plasma to tissue and vice versa, respectively (H. Mattie et al., J Pharmscokinet Biopharm, I_55, 191, 1987). Based On the l-compartment model C could be eKpressed for each patient by pharmac~kinetic constants and thus the equation for dCT/dt was transformed to a an equation with k and k T as unknowns. From these equations mean values ~f k and k were calculated, using non-linear regressio~ T analysls (H. Mattie et al., Br_~ Clin P h a r m ~ , 24, 179, 1987). Values were 1.88 h and 0.34 h , respectively. The mea~ elimination r~te c o n s t a n t for plasma was 1.33 h- . Using those values it can be calculated that the maximal concentration will be reached 37 minutes after bolus injection of cloxacillin. Dept. Infectious Diseases, University Hospital, P.0. Box 9600, 2300 RC Leiden, The Netherlands

THE ~ 9 ~ C ~ OF VARIOUS INJECTION SITES AND POST-INJECTI(IN MASSAGE ON PHA~MACOKINETICS OF INTRAMUSCULAR ADMINISTRATION OF AMIKACIN SULFATE Akinori URAE,Toshiaki AMAMOTO, Shin IRIE, Haruki MORISE Purpose: Aminoglycoside antibiotics have a narrow therapeutic spectrum, and have conventionally been used by intramuscular injection. Absorption and excretion of a drug have been kno%~n to be affected by the location of the injection site and with or without massage of the injection site. The present study was performed using healthy adult males as subjects. The study was designed to compare the effects of intramuscular administration as amikacin sulfate on its absorption and excretion as changed injection sites with or without injection site massage. Results are reported below. Method: Eight healthy adult males were selected as subjects. They were divided into 4 groups corresponding to drug injection into the deltoid muscle and into the mesogluteus muscle, with and without massage of the injection site. The subjects were allotted to each group using a modified crossover design. Blood samples were taken before administration and at intervals of 0.17, 0.33; 0.5, 0.75, I, 1.5, 2, 4, and 8hours after administration, and FPIA measurements were performed. A non-liner least square program was used for pharmacokinetic analysis and calculation of the respective pharmacokinetic values. Result: Maximum blood levels for the deltoid muscle injection followed by massage group (AI group) were achieved at 0.728 + 0.263 (mean _+ SD) hr. For the deltoid muscle injection without massage group (A2 group), these values were 0.812 + 0.320 hr. For the mesogluteus muscle injection followed by massage group (BI group), values were 0.781 + 0.610, while for the mesogluteus muscle injection wTthout massage group (B2 group) values were 0.875 + 0.133. Massage thus provided a slight reduction in time, but this difference was not significant. No difference due to administration site was noted. Maxium blood level,area under the blood level curve, and biological half-life were all examined, with no significant difference noted inter-each group.

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PP 14.32

PHARMACOKINETICS OF OFLOXACIN IN HUMAN SKINBLISTER FLUIDS AND SERUM

QUININE PHARMACOKINETICS AND TOXICITY IN NIGERIAN SUBJECTS E: A. Oyewo~ C. P. Anyabuik% O. O. Bola~i and P. A. F. Dixon. Chloroquine (CQ) - resistant falciparummalaria is increasingly becoming a major health problem in Nigeria. Previous studies in South-East Asia have revealed the pharmacokinetics and toxicity of Quinine in CQ-resistant malaria (White et al, Am. J. Med. 72, 564 1982, Philips et al, Br. J. Clin. Pharmac. 21, 677, 1986). We are aware of the ethnic differences in the metabolism and pharmacokineticsof certain drugs (Branch et al, Clin. Pharmac Ther. 24, 283, 1978; Eichelbaum and Woolhouse, Eur. J. Clin. Pharmac. 28, 79, 1985). Each subject received 600mg of Quinine base orally with 200ml of water. BP and PN were recorded in duplicates and Pre- and Post-ECG measurements were recorded, saliva and blood concentrations of Quinine were analysed using a Varian model 5000 liquid chromatograph. There was a poor correlation (r = 0.22) between saliva and blood concentrations of Quinine. The Pnarmacokinetic indices were, total clearance (01). 1.26 ~ 0.ihml/min/kg apparent volume of distribution (Vd) 1.50 + 0.hlL/kg, elimination half-times (t89 14 + 3h and el~mination constant (Kel) 5 ~ I x 10-Z/h. --There was no clinical or electrocardiographic evidence of oardiotoxieity in our subjects, although there was a slight but insignificant drop in both systolic and diastolic blood pressure and an initial significant drop in heart rate which returned to normal after 4h. Four subjects whose Quinine blood concentrations exceeded 7mg/l showed side effects ranging from dizziness~ blocking of the ears, nausea~ and fainting spells. There is therefore need for proper assessment of risk/benefit ratio in Quinine chemotherapy during falciparum malaria. Department of Medicine & Pharmacology, 0bafemi Awolowo University, Ile-Ife, Nigeria.

B.Warlich 1 , H.C.Kortinq 2, M.Sch&fer-Kortinq 1 a n d E . M u t s c h l e r 1 In order to derive the penetration kinetics of ofloxacin into tissue fluids - except in septicaemia the concentration of an antibacterial agent in the blood is not important - drug concentrations were determined in cantharides blister fluid (CBF), suction blister fluid (SBF) and in serum. Blood and blister fluid samples were drawn from 6 healthy volunteers, receiving 200 mg of]oxacin twice daily for 3 and a half days. Cantharides blisters and suction blisters were developed prior to and after the ultimate dose. Serum and blister fluids were collected before the last dose and for 36 h thereafter. Ofloxacin was quantified on a reversed-phase HPLC system. Pharmacokinetic parameters of ofloxacin in both types of blister fluid were in accordance. Cmax, however, was higher in SBF (2.86 p, g/ml + 0.32) than in CBF (2.25/~ g/ml + 0.46) (P < 0.05). Time to peak concentrations of ofloxacin (tmax) were reached simultaneously in both blister fluids (SBF 3.0 h; CBF 3.5 h), but later than in serum (1.9 h). Terminal half-lives in blister fluids and serum were almost identical (6.3 - 7.0 h). Ofloxacin readily penetrated into blister fluids, as shown by high AUC ratios (AUCskin blisters/AUC serum)' 1.1 for CBF and 1.3 for SBF. Ofloxacin levels in the tissue compartment are sufficiently exceeding the MIC90 values of e.g.S, aureus, S. epidermidis, N. gonorrhoeae, H. influenzae and various Enterobacteriaceae. 1pharmakologisches Institut far Naturwissenschaftler der Johann Wolfgang Goethe-Universit~t, Theedor Stern Kai 7, Geb&ude 75A, D-6000 Frankfurt/M 2Dermatologische Klinik und Poliklinik der Ludwig-Maximilians-Universit~t, D-8000 M~nchen

PP 14.33

PP 14.31 The Pharmacokinetics

of Chloroquine

Secretion

in the saliva of healthy man By Dr.(Mrs) 3.E. Ogbuokiri, Senior Lecturer/Consultant P harmecolooist, Department of Pharmacology & Therapeutics College of Medicine E nugu. Five healthy adult subjects were oiven 600mg tablets of chloroquins (NivaquineR) as a single dose. Concentrations of chloroquine and its metabolites were measured in the mixed stimulated saliva samples as well as plasma collected at the same times from the subjects. Chlorcquine (CQ) was detectable in plasma and salivehYsthe lh samplinq time. Peak saliva levels, C max of CQ ranged from 532.8 ng/ml - 1075.3 ng/ml with a mean of 760.2+156.3 s.d. for the saliva samples and in plasma, ~Pmax ranged from 4 3 7 . ~ - 901.7 ng/m] with a mean of 603.8~320.6 ng/ml. Saliva Tmax ranged from 2-7 hours- (mean 3.6+--- 1.2h) while plasma Tmax ranged from 2-6 hours (mean 3.2 + 0.18h) under the same conditions. The o~ncentration o-f chloroquine in saliva was found to be higher than in plasma for samples t~ken at the same time and agrees with data previously reported in the literature. The measurement of drugs in saliva has far-reaching implications for therapeutic drugs monitoring, patient compliance and determination of pharmacokinetic parameters in man. Reference:

Cgunbona,

Saliva s e c r 6 t i o n J. Pharm.

F.A. et el.

of chloroquine

Pharmacol.

38 : 5 3 5 -

(1986) in man.

537.

P H A R M A C O K I N E T I C S OF M O R P H I N E IN C A N C E R P A T I E N T S F O L L O W I N G M U L T I P L E A D M I N I S T R A T I O N OF C O N T R O L L E D R E L E A S E M O R P H I N E T A B L E T (MS CONTIN) IN J A P A N E S E K.Oguchi, S . K o b a y a s h i , H . Y a s u h a r a , E . U c h i d a , H.Doi*, S.Usami*, S . M a t s u i * and T . O g u m a * * MS contin t a b l e t is a n e w l y f o r m u l a t e d c o n t r o l l ed r e l e a s e m o r p h i n e s u l f a t e tablet. It has the a d v a n t a g e of less f r e q u e n c e of d o s i n g over c o n v e n t i o n a l dosage forms b e c a u s e of the long lasting effective plasma concentration. In this study, p h a r m a c o k i n e t i c s of m o r p h i n e and its m e t a b o l i t e s (M-6-G; m o r p h i n e - 6 - g l u c u r o n i d e , M-3G; m o r p h i n e - 3 - g l u c u r o n i d e ) were s t u d i e d in patients with advanced cancer following multiple a d m i n i s t r a t i o n of MS contin. M o r p h i n e was w e l l a b s o r b e d from MS c e n t i n t a b l e t c o m p a r a b l y w i t h aqueous morphine hydrochloride. The p l a s m a c o n c e n t r a t i o n of M - 6 - G and M - 3 - G were 5 to i0 fold and 40 to 70 fold higher, r e s p e c t i v e l y , than those of morphine, s u p p o r t i n g that m o r p h i n e is s u b s t a n t i a l l y m e t a b o l i z e d at the first pass t h r o u g h the i n t e s t i n e and liver. The e l i m i n a t ion h a l f - l i v e s of m o r p h i n e and its m e t a b o ! i t e s were c o n s t a n t d u r i n g m u l t i p l e dosing, but the ratios of C and AUC of m o r p h i n e at s t e a d y max state to those a f t e r the first dose were greate r than the c a l c u l a t e d a c c u m u l a t i o n factor. On the o t h e r hand, the ratios of C of M - 6 - G and M3-G were c o m p a r a b l e w i t h t h ~ a ~ c c u m u l a t i o n factor. The n o n l i n e a r i t y about m o r p h i n e and the l i n e a r i t y about the two m e t a b o l i t e s d u r i n g m u l t i p l e d o s e s m a y be e x p l a i n e d b y the v e r y small r e d u c t i o n of first pass m e t a b o l i s m w h i c h is t h o u g h t to be c a u s e d by a d v a n c e of cancer. D e p a r t m e n t of P h a r m a c o l o g y and S u r g e r y (*), School of Medicine, S h o w a University, 1-5-8 H a t a n o d a i , S h i n a g a w a - k u , T o k y o 142, Japan. S h i o n o g i R e s e a r c h L a b o r a t o r i e s (**), S h i o n o g i & Co., L t d . , O s a k a 553, Japan.

A 308

PP 14.34 IS DISPOSITION OF IDARUBICIN (IDR) DOSE DEPENDENT? Prem K. Narang and Mirjam Gerber IDR is a new semisynthetie derivative of daunorubicin (DNR) in which a methoxy group from position 4 has been replaced by a hydrogen. In preclinical models, IDR has shown more potency and less eardiotoxicity then DNR. Several Phase I & II studies have evaluated its disposition following I.V. doses in patients with adult and pediatric leukemia and in those with solid tumors. Whether IDR kinetics show a dose proportional response or not, has not yet been addressed. We have analyzed data obtained in 55 patients from 8 studies, after IV doses of 4.2-15 mg/m 2. Three disposition parameters of IDR, terminal half-life (th,lz>, systemic clearance (CL~) and the ratio (R) of area under the plasma concentration vs. time curves for metabolite (IDR-OL) and parent were evaluated. Small patient numbers for low dose data were pooled, and divided into 4 dose levels: <7, i0, 12-14, 15 mg/m z. ANOVA with linear and quadratic contrasts was performed. No d~fference ~n mean t~.~ z (23, 19, 16 and 27 hr; p> 0.2) across the 4 dose levels was seen. Increases with dose were seen in the CLs, from 46 to 66 I/hr/m z, and R, from 1.7 to 3.7, respectively. Although not statistically significant, borderline pvalues of .07 and 0.051 for CL s and R appear to suggest dose dependent metabolism of IDR at higher doses. It is likely that the nonlinearity in IDR disposition is being masked by the large variability in estimates of its kinetic parameters. Dose dependency issue ,coupled with the equipotent metabolite, could be of clinical significance in developing newer dosing paradigms for hematologic malignancies and/or solid tumors. Clinical investigation of IDR-OL disposition should be undertaken for its confirmation. Pharmacokinetics/Pharmacodynamics Department, Adria Laboratories, Div. of Erbamont, Dublin, OH 43017

PP 14.36 CHRONOPHARMACOKINETICS OF ADRIAMYCIN IN PATIENTS WITH BREAST CANCER. P.CANAL, A.SQALLI, M.DEFORNI,C.CHEVREAU,A.PUJOL,G.HOUIN, R.BUGAT.

Different studies have demonstratedtime-dependent changes in the pharmacokinetics o1 drugs, in particular antioancerous drugs. Anthracyclines, principally adriamycin (ADR), are the mostcurrentlyused drugs in breastcancertherapy.We haveundertaken this work to investigatewhetherthe pharmacokineticsof ADR was dependent upon the hour of administration. 15 patients suffering from breast cancer were included in this study. They have received a combined chemotherapyat two circadian stages separated by 12 hours, consisting of 5-fluorouraoil (800 mg/m2 as a 15 rain. infusion) at 8.45 am or pm, adriamycin (50 mg/m2 as an iv bolus) at 9 am or pm and then cyclophoephamid (5QO mg/m2 as a 1 h perfusion).The two randomizedcoursesof this protocolwereperformed in each patient at a four week interval and plasma phermacokinetic parameters were compared. Blood samples werecollectedover24 hours (N=14). PlasmaADR concentrationswere evaluated by HPLC with fluorimetric detection. Pharmacokinetic parameters were calculated accordingto a three compartmentmodel and comparedby F test. The mean pharmacokinetic parameters obtained at the two circadian stages are summarized in the lollowingtable.

T1/2,,~(h) T1/2fl (h) T1/2~"{h) CL (I/h/m2) Vdss (I/m2 Vd~ (I/m2) AUC (mgllxh) MRT {h)

9h A,M. 0.059 +/- 0.018 0.282 +/- 0.181 12.62 +/- 6,87 38,78 +/- 18.41 377.2 +/- 203.6 631.7+/- 324 1.562 +/- 0.923 10.27 +/- 9.96

9h P.M. 0.063 +/- 0.019 0.399 +/- 0.253 22.62 +/-23.49 30.42 +/- 13.43 460.9 +l* 210.5 754.8 +/- 303 2.247 +/- 2.081 21.12 +/- 8.85

F test 1.078 1.952 11.675 1.881 1.oe9 1.140 5.084 9.313

We noticed that the elimination phase (p<0.001). the AUC (p<0,05) and the MRT (p<0.001) wereincreasedwhenADR was administeredin the evening. These pharmacokinet{cdifferencesmight likelyinfluencethe toxic effects of ADR and the clinical response. An evaluation of the hematologictoxicity of these 2 circadian protocols is actually under investigation. Centre CLAUDIUS REGAUD, 20 rue du Pont Saint Pierre, TOULOUSE, FRANCE.

PP 14.35 ESTRADIOL-LINKED NITROSOUREAS: NEW ANTICANCER DRUGS WITH CLEARLY MODIFIED PHARMACOKINETIC PROPERTIES. B. BETSCHI~M.R. BERGERI~B. SPIEGELHALDER1, G. EISENBRAND 2& D. S C H ~ H L ! lInstitute for Toxicology and Chemotherapy, German Cancer Research Center, lm Neuenheimer Feld280,D-6900 Heidelberg, FRG 2Department of Food-Chemistry and Environmental Toxicology, University of Kaiserslautern, D-6750 Kaiserslautern, FRG.

The pharmacokinetics of 1-(2-chloroethyl)-1-nitrosocarbamoylL-alanine- estradiol-17-ester (CNC-alanine-estradiol-17-ester) a new estradiol-linked anticancer drug and the unlinked DNA-crosslinking agent 1-(2-chloroethyl)- 1-nilrosocarbamoyl-L-alanine (CNC-alanine) have been studied in methylnit~osourea-induced female SpragueDawley rats after equimolar intravenous and oral administration. In comparison to the uulinked single agent, the CNC-alanineestradiol-17-ester showed a 3-fold longer halflife in plasma and a 3 times larger volume of distribution. The distribution after intravenous administration was nearly 3 times faster. The absorption after peroral administration was likewise 2 times faster. The bioavailability of the estradiol-linked drug was determined to be 52%. After application of CNC-alanine-estradiol-17-ester the cytostafic metabolite CNC-alanine was found indicating the cleavage of the ester bond. CNC-alanine generated from CNC-alanine-estradiol-17-ester showed a 50% longer halflife than when applied directly. The results indicate that linking 2-chloroethyl-nitrosoureas to estradiol can result in new anticancer agents with modified properties in comparison to the unlinked single agent. The observed higher antineoplastic activity of the hormone-linked drug can mainly be attributed to differences in the pharmacokinetic behaviour.

PP 14.37 VARIABILITY IN PHARMCOKINETICS QF CODEINE AFTER INTRAV~NOUS AND O~AL ADMINISTRATION TO ~OSTOPERATIV~ PATIENTS, K.Persson; M.Hammarlund-Udenaes, U.Mortimer; A.Rane: The i n t e r i n d i v i d u a l v a r i a b i l i t y in analgesic e f f e c t and side e f f e c t s o f codeine may p a r t l y be due to v a r i a b i l i t y in i t s metabolism. We have studied the intravenous and o r a l k i n e t i c s o f codeine in p o s t o p e r a t i v e p a t i e n t s t h a t underwent c h o l e c y s t ectomy. An i v dose o f 20 mg was administered about 70 hours a f t e r surgery, Two to three days l a t e r an oral dose o f 50 mg was administered. Plasma samples were c o l l e c t e d during a 24-hour period. Samples were analysed with HPLC For codeine and i t s m e t a b o l i t e s morphine, norcodeine and codeine -6-glucuronide. Results from 12 pat#ents show an average plasma.clearance f o r codeine o f 0.65:0.26 (range 0.35-1.35) l . h - l . ~ g - I and a volume o f d i s t r i b u t i o n (Vd,ss) o f 2.2-0.6 l . k g - I . The terminal h a l f - l i f e was 2.57• h. The b i o a v a i l a b i l i t y o f codeine v a r i e d g r e a t l y between subjects from 12-84%. The average b i o a v a i l a b i l i t y was 40• The h a l f - l i v e s o f norcodeine and c o d e i n e - 6 - g l u c u r o n i d e were 2.89• h and 4.00• respectively. The AUC r a t i o s o f metabolize to codeine Show a great dominance f o r c o d e i n e - 6 - g l u c u r o n i d e ( ( r a t i o 7.6 ( i v ) and 22 ( p c ) ) . The norcodeine/codeine r a t i o was 0.14 ( i v ) and 0.23 ( p c ) ) . Morphine c o n c e n t r a t i o n s were below the d e t e c t i o n l i m i t , which i n d i c a t e s a formation o f morphine from codeine o f less than 10%, Our data i n d i c a t e s great i n t e r i n d i v i d u a l v a r i a b i l i t i e s both in clearance and b i o a v a i l a b i l i t y o f codeine. These may be important c o n t r i b u t i o n s to the observed v a r i a b i l i t y in response, I . Div. C l i n . Pharmacology, U n i v e r s i t y H o s p i t a l , S-751 85 Uppsala, Sweden. 2. Dept. o f Biopharmaceutics and Pharmacokinetics, U n i v e r s i t y o f Uppsala, S-751 23 Uppsala, Sweden.

A 309

PP 14.38

PP 14.40

THE DETERMINATION OF RENAL AND METABOLIC CLEARANCE5 OF PARACETAMOL AND ITS CONJUGATES BY 4 HOUR POST DOSE URINE ANALYSIS H.A. Wynne and F. Kamali Paracetamol clearance (CIp) con be expressed as CIp=ClR+Clo+CIs+CIGs H, where ClR is the renal clearance of unchanged paracetamol ( P ) and ClO, Cl$ and ClG5 H are the metabolic clearancesof the glucuronide (P(3),sulphate (PS) and glutathione [cysteine(PC)+ mercapturate ( PM)] derived conjugates. Provided thatIO0 % of a given dose is accounted for in the urine, the relativecontributionof each metabolite is given by the fractionalcontent of the metabolite in urine. Nearly all of a therapeuticdese of paracetamol is recovered in urine as the free drug and its metabolites,24h following its administration to healthy subjectsand the renal clearance of paracetamol and the metabolic clearances of itsmBtabolitescan be determined by the measurement of fractionalcontent of the drug and itsmetabolites in 24h urine collections, In this study, the renal clearance of paracotamol and the metabolic clearances of its metabeliteswere determ ined by measurement of the urinary content of the drug and its metabolites in the O-4h urine collectionsand were compared with those determined from the 0-24h urine collections,followingan I.V.administrationof parecetemol ( Ig) in healthy volunteers. The O-4h fractionalexcretion of unchanged paracetamol and its metabolites in urine was found to be virtuallythe same as those determined from the 024h collections.

MULTIPLE DOSE PHARMACOKINETICS OF D-PROPOXYPI~NE CAN BE EXPLAINED BY ACCUMULATION. P. Thomann, H. Hengy, K.-O. Vollmer (1), N E. Larsen (2)

% oftotaiparecetamolexcretedes; PS PG P O-4h 40.4• 54.4• 3.5• 0-24h 42.1• 52.2• 3.2•

PC 0.8• 1.2•

PM 0.9• 1,3•

This indicatesthat the rena} clearance of the uncejugatedparacetamol and metabolic clarence of paracstamol metabol~tescan s~tisfactorily be determinedfrom O-4h urine collections. Department of" Pharmacological Sciences,Wolrson Unit of Clinical Pharmacology, Claremont Place, The University, Newcastle Upon l'yne, NE1 7RU. U.K.

As there has been conflicting discussion on the explanation of multiple dose kinetics of d-propoxyphene (dp), two studies were performed using a 150mg CR-tablet (DEVELIN RETARD): i. Single dose two-way cross-over study on 12 subjects; 150mg dp were gfven as immediate release capsule and as CR-tablet. 2. Multiple dose study on 12 subjects: 150mg dp (one CR-tablet) was given BID for 5 days. Four subjects participafed in both the single dose and multiple dose study. P)asms profiles of dp and nordextropropoxyphene (ndp) were determined by GLC-MS at appropriate times throughout the studies. Kinetic model parameters were ca]cu|ated with TOPFIT. fn the single dose study, mean dp termina] half-lives were estimated to be approximately ]3 h f!or dp and 28 h for ndp. The half-value duration was prolonged threefold and a lower Cmax occurred later after the CR-tabIet compared to the capsule. In hhe multiple dose study, terminal half-lives ~tter the last dose were approximately 28 h for dp as well as for ndp. Due to the longer half-life, the plasma concentration time courses o f dp and ndp following multiple doses could be described by a three compartment pharmacokinetie model. For the four subjects who partlcipated in both studies, the data following multiple doses are consistent with those following a single dose. The data for these subjects demonstrate that the diff~cu]tles in explaining multiple dose pharmacokinetics of dp using s~ngle dose parameters may be caused by underestimating the terminal hail-life after single dose administration. Thus, dp pharmacokfnetics following multiple doses can be described by a pharmaeokinet|c model and are consistent w~th single dose pharmacokinetics. l) Gbdecke Research Institute, D-7800 Frelburg FRG 2) Glostrup Hospital 2600 Glostrup, Denmark

PP 14.39

PP 14.41

THE DIFFUSION OF PARACETAMOL INTO THE CEREBROSPINAL FLUID IN HUMANS B. Bannwarth, P. Netter, F. Lapicque, D. Maire, P. Pdrd, E. Boccard, R.J. Royer, A. Gaucher Many convincing data have reported a central antinoeiceptive component to the antialgesic action of non-narcotic, antipyretic analgesics. Unfortunately the kinetics of these drugs into the eerebrospinal fluid (CSF) has been little studied in man. We investigated the diffusion of paracetamol into CSF in patients with nerve-root compression pain. Thirty in-patients (17 men & 18 women) aged 54 + 12 years and weighing 73 + 14 kg entered the study after expressing verbal informed consent. They received a single dose of propacetamol, which is a prodrug immediately and completely hydrolyzed to paracetamol by plasma esterases. Twenty minutes to 6 hours after an intravenous injection of 2g propacetamel (equivalent to ig paracetamol), one blood sample and one of CSF (myelography) were drawn at the same time in each subject. Paracetamol was assayed by HPLC. The pharmacokinetic data were analyzed using the SIPHAR software. Paracetamol crossed rapidly the blood-brain barrier, according to its lipid solubility and to its low protein binding. The CSF entry half-life was 1.4 h. The mean CSF concentration was 1.5 ~g/ml in the earliest samples and then increased up to 5.3 pg/ml at 2h. Plasma concentrations decreased with a half-life of 2h so that they became equal to the 08P concentrations at 3h. After attainment of equilibrium, disappearance of paracetamol from CSF and plasma occurred with similar half-lives. Finally the mean residence time was about 60 % higher in the CSF than in the plasma (4.8 and 2.9 hours, respectively). D@partement de Pharmacologie Clinique, URA CNRS 2288, Faeult@ de M@decine de Nancy, 54505 Vandoeuvre C@dex & Laboratoires UPSA, 92500Rueil-Malmaison (France).

SUSTAINED RELEASE FORMULATION OF FENFLURAMINE (PONDERAX) B,S.Doshi, B.L.Chauhan~ R.D.Kulkarni~ C.Loucq** B,LeBras*7 P . K l i p p e r t ~ C.Paillel*~ J.Ph.Jeanniot** The bioavailability of a new sustained release formulation of fenfluramine hydrochloride (Ponderax 60 mg)was compared with that of a reference formulation after a single oral administration to 8 healthy volunteers. The plasma concentrations of the unchanged drug and its major metabolite norfenfluramine were measured by gas chromatography with nitrogen-selective detection. The maximum plasma concentrations of fenfluramine were significantly lower for the sustained release formulation than for the reference one (30.8 • 7.0) and 57.8 Z 19.3 ng.ml -l respectively, (p~ 0~05). Maximum plasma levels remained nearly constant from 8 to 16 h after administration of the slow release formulation whereas a peak plasma level was reached about 3 h after administration of the ref@;ence formulation. The areas under the plasma concentration of fenfluramine versus time curves showed no statistically significant differences between the two formulations (p) 0.05).The areas under the plasma concentration-time curves of norfenfluramine were slightly different but not accurately determined and the maximum plasma concentrations of the metabolite were similar for both formulations. Based on these results, it can be concluded that the extent of absorption is equivalent for the 2 formulations. From the pharmacokinetic results of this study the new formulation showed good slow release characteristics and should be useful for once daily dosing schedule. * The Himalaya Drug CO. R&D Centre, 251, Dr.D.N.Road, Bombay, INDIA. ** Bio Pharmacie Servier, 5, rue de Bel Aire, FRANCE.

A 310

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G6decke Research Institute D-7800 Freiburg, FRG * Benedikt-Ereuz-Rehabilitations Zentrum, D-7812 Bad Krozingeu

MULTIPLE DOSE SAFETY, TOLERANCE AND PHAEMACOKINETICS OF HP 029 IN ELDERLY M ~ : A POTENTIAL AGENT FOR THE TREATMENT OF ALZHEIMER'S DISEASE S. K. Puri~ E. B. Lassman~ I. Ho~ R. Rsu and J. Lazowski KP 029 (l,2,3,4-tetrahydro-9-aminoacridin-l-ol-maleate) is a new drug undergoing Phase II clinical testing for the treatment of Alzheimer's Disease. A randomized, doubleblind, placebo (P) controlled study was done in 56 healthy elderly men (i0 on HP 029 and 4 on P per dose). They received 25, 50 or i00 hid or i00 mg tid respectively for ~8 days and a final dose on Day 29. The safety and tolerance were assessed at various intervals after dosing. Plasma levels of HP 029 were determined by BPLC for assessment of p ~ c o k i n e t i c s of HP 029. There were no clinically meaningful or drug-related changes in any of the physical examinations, ECGs, audiograms, ophthalmologic examinations, or laboratory tests after any dose of HP 029. A total of 9 subjects reported one or two episodes of possibly/probably drug-related diarrhea (six in the 100 mg bid dose group; 5 on HP 029 and 1 P; and 3 on HP 029 in the lOOmgtid dose group). HP 029 is well absorbed after oral administration. The plasma concentration reached the peak in approximately 1 hour and the drug was eliminated with a half-life of about 2-3 hours. After steady state levels were reached in about 2 to 3 days of multiple dosing, there w&s no further accumulation of the drug. The eu~Jlative percent of dose in the urine on Day 1 (0-12 hours) ranged from 11-14% for the bid treated groups; and w&s 12% (0-6 hours) for the rid treated group. The cumulative percent of dose in urine on Day 29 (0-48 hours) was 15-22% with the bid regimen groups; and 30% with the tid regimen. Additionally, the average percent of dose excreted unchanged in urine over the entire treatment period (30 days) ranged from ii.2-22.3%. The acceptable safety, tolerance and favorable pharn~cokineties characteristics of HP 029 justify the ongoing testing in Alzheimer's patients. Roeehst-Roussel Pharmaceuticals Inc., Route 202-206, P.O. Box 2500, Somerville, NJ 08876-1258 USA

PP 14.43

PP 14.45

DOSE-LINEARITY OF THE NEW ANTICONVULSANT GABAPENTIN AFTER MULTIPLE ORAL DOSES D. T~rck, K• Vollmer, H. Bock bradeT*~ A~_Sedman* Gabapentln, a GABA analog being studied for the treatment of epilepsy, is eliminated in man solely by renal excretion and not metabolized. Twelve healthy volunteers received 100, 200, and 400 mg doses of gabapentin orally every 8 hours for 7 days in a three-way crossover design. Urine and plasma samples were collected to characterize steady state pharmacokinetie parameters. Samples were analyzed for gabapentin concentrations using a specific, validated }{PLC method. Gabapentin pharmacokinetic parameters are presented in the following table:

Medifoxamine: Oral tolerance and phazmacokinetic study in healthy volunteers. S. Saleh, A. Johnston and P. Turner Medifoxamine is a monoamine reuptake inhibiting antidepressant drug undergoing clinical investigation (Poirier, J. and Viellefond, H. Psychologic Medicale, 18, 1925-1930). As part of an investigation of its kinetic and dynamic properties, it is necessary to detemuine its absolute oral biov-ailability in man. Single oral doses of 50 and 100 mg orally were not associated with any objective or subjective side effects but produce plasma levels which were too low to measured accurately. Therefore, we carried out a tolerance study with larger doses to obtain ~ s u r a b l e plasma concentrations Ascending oral doses of 200, 500, 750 & 1000 m g of medifoxamine were given, an increased dose was given only after we had detemmined that the previous dose was well tolerated by the subjects. Plasma samples were analysed using a specific HPLC method. Standard phamvacokinetic parameters were calculated by standard u~dlniques using tJt~ STRIPE c~l~uter program (Johnston, A. and woollard, R. J. P ~ c o l . Meth. 9:193). Medifoxamine was well tolerated and there were no changes in vital signs. Unchanged medifoxand_ne was detected in plasma of all subjects. The drug was rapidly absorbed and peak plasma concentration were acheived about 1 hour after administration. There after the elimination profile was biphasic with a mean terminal half life of 1.7 S~[ 0.02 hours. There were no significant dose related changes in absorption half life, elimination half life, clearance, lag time or vol~ne of distribution. Area under the plasma concentration-time curve and ~ plasa~ concentrations were linearly correlated with the dose (r = 0.80 ) suggesting that medifoxamine does not have dose dependent kinetics over the dose range studied. Clinical pharmacology, St. Barthol~' s Hospital, London ECIA 7BE, UK.

MULTIPLE-DOSE PBARMACOKINETICS OF THE NEW ANTICONVULSANT GABAPENTIN K.-O. Vgllmer, D. Turck, F. Wagner*~_E_~_J~_hnchen~* H. Anhut, P. Thomanl! Gabapentin is a new GABA-analog amino acid which has been shown to be effective as an antieonvulsant in various clinical trials. To study multiple dose pharmacokinetics of gabapentin, eight healthy male volunteers received 300 mg gabapentin TID for five days at 8 am, 2 pm and 8 pm. This dosage schedule was derived from clinical practice. Three plasma profiles (ist, 7th and 13th dose) and all predose gahapentin plasma concentrations were measured by a specific and validated HPLC-method. All urine voided by a volunteer during the study was collected in fractions and analyzed for gabapentin by the same method. The gabapentin plasma concentration time profiles were fitted using the TOPFIT program package. The amount of Gahapentin excreted unchanged into urine was not altered throughout the study, indicating constant absorption after multiple doses, s~nce gabapentin is not metabolized and only excreted by the kidneys. In summary, 55 % of the total dose administered was recovered in urine. Steady-state determined from constant predose plasma concentrations was achieved during the second day. The measured gabapentin plasma concentrations agree with the predicted plasma concentration-time course. Pharmacokinetic parameters derived from the last dose interval (tl/2:5.9 h, Tmax: 2.8 h, Clren: 117 ml/min) were similar to those obtained earlier from single dose treatments. Oabapentin pharmacoklnetics and absorption are not altered following multiple oral doses.

j Dose (pg/ml)

Cmax Tmax AUC

(pg*h/ml)

tl/2

(ml/min) (h)

(h) (%)

~

i00 mg

200 mg

400 mg

1.86 2.1 Ii.0 79 122 5.1

3.29 2.0 19.6 69 122 5.6

5.50 2.1 33.3 64 ]31 6.1

Renal clearance and Tmax were simi]ar for all doses tested. Half-life was slightly enhanced, hut this increase is not clinically important. The increase of AUC and Cmsx was not strictly doselinear. The deviations are rather small and axe due to lower absorption at higher doses, as shown by a reduced fraction excreted unchanged in urine (Ae %). Thus, no relevant changes were found in disposition parameters. Absorption was reduced at higher doses. G6decke Research Institute, D-7800 Freihurg, FRO * Parke Davis Pharmaceutical Research Division, Warner-Lambert Company, Ann Arbor, Ml 48105, USA

A 311

PP 14.46

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Withdrawn

LIV. 52 AND ALCOHOL "HANGOVER" R.D.Kulkarni, and B.L. Chauhan Acute alcohol consumption is known to produce irmaed-

iate effects on psychomotor function and delayed feeling of "hangover". Acetaldehyde, an intermediate metabolite, produces unpleasant effect on CNS and may be responsible for "hangover". Liv.52, a herbal preparation based on ayurveda is shown to alter kinetics of ethanol and reduce acetaldehyde levels.Present study discusses whether this novel action would reduce "hangover" effect. 5 male volunteers consumed 60 ml whisky every 30 minutes for 4 doses in the evening, 2 hours after single dose of placebo or Liv.52 administration.Blood and urine were collected for ethanol and acetaldehyde estimation at i and 12 hours, i00 mm visual analogue scale and symptom check list was given to assess subjective feelings at 12 hours.

Placebo Liv.52

Blood Ethanol(mg%) i hour 12 hours 63.50* 25.04** +6.04 +9.48 82.23" -7.46** +3.90 +1.22

Urine Ethanol (mg) i hour 12 hours 67.12" 111.70"* +12.28 +16.57 -31.18" -48.61"* + 6.62 +15.33

P ~0.05 (unpaired 't' test) Following Liv. 52, i hour ethanol levels were significantly higher and urine ethanol significantly lower. Blood and urine ethanol levels and urine acetaldehyde levels were significantly lower at 12 hours. Scores on I00 mm scale showed improvement with Liv.52. Single dose of Liv.52 may reduce the hangover effect of acute alcohol intake due to low ethanol levels at 12 hours.

The Himalaya Drug Co. R&D Centre, 251, Dr.D.N.Road, Bombay 400 001, INDIA.

PP 14.47

PP 14.49

~ F ~ C T S OF FATTY FOOD AND ALCOHOL ON PHARMACOKINLm~CS AND--DYNAMICS OF DIAZEPAM T. Sepp~l~, K. Ara~ko, R. Kohtala and T. Ahokas The effects of fatty food and ethanol (i g/kg) on the pharmacokineties and -dynamics (Maddox wing, flicker fusion test, nystagmus) of orally taken diazepam (15 mg) were studied in six healthy male volunteers. The subjects were given double-blind (drinks) and cross-over at one week intervals a) placebo drink + low fat meal (three pieces of crisp bread) + diazepam 1 h later (group DZP), b) alcohol drink + low fat meal + diazepam (group A+DZP), and c) fatty meal (bread+margarine 5 g/kg) + placebo drink + diazepam (group F+DZP). Serum samples were collected and psychomotor tests administered at baseline, just before drug intake and 0.5, i, 1.5, 2, 3, 5, 8, 12, 24, and 48 hours after it. Serum diazepam and uurdiazepam were assayed chemically by a gas chromatograph. Serum benzodiazepine (BZ) activity was measured by a radioreceptor assay (RRA) as well. Serum free fatty acid (FFA), triglyceride and alhumine levels were also assayed. According to chemical assays F+DZP produced significantly lower and later peak diazepam levels than DZP (380 ng/ml at 3 h and 670 ng/ml at ] h, respectively). Alcohol inhibited formation of nordiazepam. AUCs according to data from chemical assays did nut differ significantly between the groups but according to RRA data F+DZP and A+DZP (which increased serum FFA) resulted in significantly higher AUC than diazepam only. Psychomotor effects of DZP and F+DZP were in agreement with serum BZ activity. When the subjects were on DZP acute tolerance (clockwise hysteresis loop) was clearer than when on F+DZP. The results suggest that raised FFA levels increase BZ activity in serum. On the other hand, rate of absorp~on may determine the development of acute tolerance to diazepum. National Public Health Institute, Dept. of Biochemistry Mannerheimintie 166, SF-O0300 Belsinki, Finland, and Department of Pharmacology and Toxicology, University of Helsinki, Siltavuorenpenger I0, 00170 Helsinki, Finland

EFFECT OF LIV.52 - HERBAL PREPARATION ON ABSORPTION AND METABOLISM OF ETHANOL IN HUMANS. B.L. Chauhan, and R.D. Kulkarni. Excessive ethanol consumption is emerging as the prime cause of chronic liver disease. Ethanol induced liver damage is due to accumulation of acetaldehyde resulting from stimulation of Phase I metabolism in chronic alcohol users. Liv.52, a herbal formulation, based on ayurveda is known to protect liver from damage produced by toxic substances including alcohol. In 8 social drinkers, effect of single dose of Liv.52/Placebo was studied on ethanol absorption after ingestion of 30 ml of whisky in 5 minutes. The t i/2 absorption with Liv.52 was (3.62 ~ 0.54 mins) significantly less than with placebo (6.29 ~ + 0.89 mins). The peak concentration with Liv.52 (49.93 - 2.31 mg%) was significantly higher than with placebo (40.49 ~ 3.99 mg%). 120 ml of whisky consumed by regular alcohol users in i hour, before and following 15 days of Liv.52 treatment, revealed significantly higher alcohol levels at 2,34 hours and significantly lower acetaldehyde levels at 3 and 4 hours with Liv.52 treatment. Blood Acetaldehyde Levels (~g/ml) Mean + SE Day

0

1 3.56 +.60

2 3.57 +.55

3 3.38* +.47

4 3.08* +.52

5 2.49 +.56

6 2.02 +.42

15

3.95 3.12 2.33* 2.13" 1.68 1.64 +.53 +.42 +.22 +.28 +.22 +.22 *P 0.05 Liv.52 enhances the rate of absorption of ethanol and there is rapid decline in acetaldehyde levels which may explain hepatoprotective effect of Liv.52 from ethanol induced liver damage. The Himalaya Drug Co. R&D Centre, 251, Dr. D.N.Road, Bombay 400 001, INDIA.

A 312

PP 14.52

PP 14.50 PHARMACOKINETIC

INTERACTION

BETWEEN

LOW

DOSES

OF ALCOHOL

AND

HASHISH

J. C~ml. R. de ]a Torre. D. Gn~wra. J. Ortn~o and J. Seoura A balanced, placebo, double blind clinical trial was designed to study the p h a r m a c o l o g i c a l i n t e r a c t i o n between low doses of alcohol (EtOH) and hashish (H). (Approuved by the Hospital de Mar Ethical Committee Ref. 28, and health authorities Ref. 85/27). Volunteers (n=96) were randomly assigned to 4 treatment groups (combination of the two drugs and their respective placebos). EtOH (total dose 0.5 mg/Kg) or its placebo was administered in an aqueous drink during a period of 30 min. H or its placebo was administered by smoking tobacco cigarettes with or without 200 mg of H (containing iI.5% of delta9-THC). Blood samples were taken for the RIA analysis of delta9-THC and 9-COOH-delta9-THC at 38, 40, 42, 45, 50, 55, 60, 75, 90, 120, 180, 240 and 360 min. After the beginning of the administration of EtOH. Experimental data (Cmax, Tmax, AUC0_240) obtained from plasma concentration/time curves have been evaluated. Results show that in the experimental groups given H wich consume EtOH the AUC0_240 for 9 - C O O H - d e l t a 9 - T H C was s t a t i s t i c a l l y significant lower than the observed in groups treated with placebo (p<0.015) . It was found that EtOH kinetics was best described by l-compartment model (SAAM-Consam software) with first order obsorption and elimination. The effect of H was found to be best described as an inhibition of EtOH elimination. The inhibition constant was determined as Ki=0.02. The AOC0_240 of EtOH was higher in groups treated with H than the calculated for placebo groups (p<0.045). The p h a r m a c o k i n e t i c interaction between EtOH and H can be e x p l a i n e d on the basis of a competitive inhibition at the metabolic level. Results obtained in this study have detected a weak but d e m o n s t r a b l e pharmacokinetic interaction. Further studies with higher doses of EtOH and H are needed to evaluate the relevance of such interaction. Dept Bharmacol, Inst M u n Inv Med (IMIM), P.Maritim 25, 08003-Barcelona, Spain. Acknowledgments: supported by a grant #Cca-8309/184 of USA-SPAIN Joint Commission for Scientific and Technologic Cooperation. The support and advice from R.Hawks (USA-NIDA) and the supply of RIA techniques for cannabinoids from C.E.Cook and K.Davies Jr. (USA-RTI) is kindly ackowledged.

T H E P H A S E I S T U D Y O F T 3 N - 1 0 1 , G O M I SI N A. DOSE STUDY

Y . O h t a k i 1) , M . l w a s a k P ) , Y . M a t s u z a k i 2) , T . M a t s u z a k i 2) , S . T a k e d a 21 , H . S a s a k i 2> , M . A b u r a d a I) , M . N a g a s a w a ll , E . H o s o y a 2> & A . S h i s h i d o 3~ Successively

after the single d o s e study, the safety a n d

p h a r m a c o k i n e t i c s of m u l t i p l e d o s e s of T 3 N - 1 0 I w e r e e x a m i n e d in h e a l t h y m a l e v o l u n t e e r s . F i v e s u b j e c t s w e r e given oral doses of 10mg or 30rag of T 3 N 101 t . i . d , r e s p e c t i v e l y f r o m d a y 1 t o d a y 7 a n d o n c e o n d a y g. A n o t h e r 5 s u b j e c t s we~:e g i v e n 2 0 r a g o f T 3 N - 1 0 1 Z.i.d. f o r 13 d a y s a n d o n c e on d a y ltd. T ] N - 1 0 1 w a s a d m i n i s t e r e d 3 0 m i n after meals except for the last dosing. The subjects remained u n d e r c l o s e m e d i c a l s u p e r v i s i o n in t h e h o s p i t a l , w h e r e b y subjective and objective symptoms, vital signs, and clinical laboratory tests were monitored. N o a b n o r m a l f i n d i n g s a t t r i b u t a b l e t o T ] N - 1 0 1 w e r e f o u n d in subjective and objective symptoms, such as blood pressure, p u l s e r a t e , body t e m p e r a t u r e , h e m a t o l o g y , b l o o d c h e m i s t r y a n d urinalysis. After administration, the plasma concentration r o s e g r a d u a l l y a n d r e a c h e d t h e s t e a d y s t a t e on d a y g by 2 0 m g t . i . d , d o s i n g , a n d on d a y g by 3 0 r a g t . i . d , d o s i n g . Plasma c o n c e n t r a t i o n o f m a i n m e t a b o l i t e o f T 3 N - 1 0 1 ( M e t B) r e a c h e d t h e s t e a d y s t a t e m o r e r a p i d l y t h a n u n c h a n g e d f o r m in e a c h case. C O N C L U S I O N : T 3 N - 1 0 1 w a s w e l l t o l e r a t e d a n d no s i g n i f i c a n t adverse T3N-IOI

effects w e r e o b s e r v e d for the e x a m i n e d doses. So, w a s r e c o g n i z e d as a safety s u b s t a n c e in healthy

volunteers. J) R C d D

Dept.for

Niban-cho,

Medical

Chiyoda-ku,

Products, Tokyo,

TSUMURA

&

CO.,

12-7,

102 3 a p a n

~) R e s e a r c h I n s t i t u t e f o r P h a r m a c o l o g y , T S U M U R A & C O . , A m l machi, Inashiki-gun, Ibaraki, 300-11 ]span a) T H E H O H S E N C L I N I C , 3 - 2 3 , 3 - c h o m e , K o m a g o m e , T o s h i m a k u , T o k y o 170 3 a p a n

PP 14.51

PP 14.53

HUMAN PHARMACOKINETICS OF PGT/IA (TIMODOLIC ACID), A NEW IMMUNOSTIMOLANT DRUG. F.Mai]land, M.Barchie|li, A.Messa, A . P o | i , and G.Coppi.

THE PHASE I STUDY OF TJN DOSE STUDY

Pharmacokinetic s t u d i e s , of PGT/IA ( 3 - L - p y r o g l u t a m o y l - t h i a z o l i d i n e - 4 - c a r b o x y l i c acid), a new i n t e r e s t i n g immunostimolant drug, in humans are r e p o r t e d . A f i r s t experiment was performed in a crossover design on 12 volunteers by admin i s t e r i n g PGT/IA by intravenous route at 200 mg and by o r a l route at 200, 400 and 800 mg ( t a b l e t s ) . A second experiment was performed in a group of 36 v o l u n t e e r s by a d m i n i s t e r i n g PGT/IA by intramuscular route at 50, lO0 and 200 mg (12 v o l u n t e e r s group) twice a day f o r 14 days. Blood samples and urine were taken at d i f f e r e n t times a f t e r the f i r s t and the 29th a d m i n i s t r a t i o n s . PGT/IA plasma and u r i n a r y l e vels were determined by HPLC method. The drug is not metabolized in man; u r i n a r y e x c r e t i o n of PGT/IA a f t e r e . v . a d m i n i s t r a t i o n is about 95%. Plasma l e v e l s of PGT/IA a f t e r i n travenous and i n t r a m u s c o l a r a d m i n i s t r a t i o n appeared to conform to a two-compartment open mod e l , while a f t e r o r a l a d m i n i s t r a t i o n appeared to conform to a one-compartment model. The b i o a v a i l a b i l i t y a f t e r oral a d m i n i s t r a t i o n is about 45%; the AUCs are p r o p o r t i o n a l to the o r a l and intramuscular dosages. The h a l f - l i f ~ of PGT/IA is 4 hours, the clearance is 5 l . h and the Vd is 30 I. PGT/IA a f t e r repeated intramuscular i n j e c t i o n s shows no accumulation nor autoinduction. Poll ResearchCentre, 20089 Rozzano, Milan (Italy)

II. M U L T I P L E

I 0 1 , G O M I SI N A.

I. S I N G L E

V . M a t s u z a k i 1> , T . M a t s u z a k P ) , S . T a k e d a l) , H . S a s a k i t) , V . O h t a k i =) , M . I w a s a k i 2) , M . A b u r a d a 2) , M . N a g a s a w a 2) , E . H o s o y a l) & A . S h i s h i d o a) T 3 N - 1 0 1 w a s o r a l l y a d m i n i s t e r e d t o h e a l t h y m a l e v o l u n t e e r s in o r d e r to i n v e s t i g a t e its s a f e t y and p h a r m a c o k i n e Z i c s . T h e d r u g w a s g i v e n a t s i n g l e d o s e s o f 10, 2 0 , 3 0 r a g r e s p e c t i v e ly in a i a s t i n g s t a t e . The subjects remained under close medical supervision for 4 days. During this period, subjective symptoms, vital signs and clinical laboratory tests were monitored. Plasma and urinary concentrations of TJN-101 and i t s m e t a b o l i t e s w e r e d e t e r m i n e d by G C / M S . T J N - 1 0 I w a s w e l l t o l e r a t e d by a l l s u b j e c t s . Clinically significant adverse effects attributed to the drug were not observed. Plasma concentration increased rapidly and reached m a x i m u m w i t h i n 0.5 to l hr a f t e r o r a l dosing. After adminis t r a t i o n o f 10, 2 0 , 3 0 r a g T 3 N - 1 0 1 , C m a x i n c r e a s e d d o s e d e p e n d e n t l y , at v a l u e s of 302.72, 60#.72 and 1010.38 n g / m l , respectively. Similar dose-dependency was observed for the AUC values. P l a s m a c o n c e n t r a t i o n o f T3~q-101 d e c r e a s e d b i phasically, and the terminal elimination half-life at each dose r a n g e d f r o m 6 to g hrs. T h e e x c r e t i o n of u n c h a n g e d T 3 N - 1 0 1 in u r i n e a n d in f a e c e s w a s o f a s m a l l q u a n t i t y . M a i n m e t o b o l i t e s o~ T 3 N - 1 0 1 , M e t B a n d M e t F w e r e d e t e c t e d in urine a n d faeces. CONCLUSION : T]N-10I w a s rapidly a b s o r b e d a n d p l a s m a c o n centration increased d o s e - d e p e n d e n t l y , after dosing orally. T h e d e c r e a s e Of T 3 N - 1 0 1 in p l a s m a w a s also v e r y rapid a n d no accumulation t) R e s e a r c h

of the drug w a s

found.

Institute for P h a r m a c o l o g y ,

TSUMURA

m a c h i , Inashiki-gun, Ibaraki~ 300-I I 3apart 2) R & / D Dept. for M e d i c a l Products, T S U M U R A Niban-cho, Chiyoda-ku, Tokyo, a> T H E HOHSEN C L I N I C , 3-23, ku, T o k y o

170 ] a p a n

& &

CO.,

CO.,

I02 J a p a n 3-chome, Komagome,

Ami-

12-7,

Toshima-

A 313

PP 14.54 THE PHASE ZIDE C.L.Zhang,

I

PP 14.56

CLINICAL

F.H.Weng,

TRIAL

OF

J.J.Jiao

CIIINESE

and

GLICLA-

T.F.Yu

Chinese glielazide (GZ) is an oral antidiabetic drug produced by Shandong Medical Industrial Institute, China. The phase I clinical trial of GZ was determined in 12 healthy volunteers with HPLC after oral administration of two dosages: 80 mg/day and 160 mg/day. Blood samples were collected after taking of drugs:O,l,2,4,8,12,24 and 36h. Kimura method was used to extract GZ from blood. The plasma concentration-time curves were fitted to an one-compartment model. The major pharmacokinetlc parameters were as follow: He 0.01, O.Olh-l; t 89 7 . 4 7 , 7.0Oh; Tmax 2.31, 2.5Oh; Cmax 5.23, 14.69ug/ml; AUC 65.61, 178.40ug.h/ml; CL 1.31, O.94L/h; Vd 13.O9, 9.58L for dosage 80 mg/day, 160 mg/day respectively. According statistical moment algorithm (O-t), MRT were 11.27, lO.51h; VRT were 67.21, 68.6Oh; AUC were 62.12, 1 8 ~ . 8 2 u g . h/ml respectively. The pharmacokinetic parameters of GZ are similar to t h a t o f F r e n c h GZ After t h e o r a l administration o f G Z I, 2, 4 h ~he blood sugar concentrations of healthy volunteers were within the normal range. No toxic hepatic,renal, cardiovascular functions and me ophthalmological changes were observed after one month of the single dosage of GZ.

Department

of College,Tianjin of China.

Pharmacology, 300070,

The

Tianjin People's

Medical Republic

PP 14.55

PP 14.57

THE PHARMACONINETIC5 OF DIHYDROOINGHA&
ZZ Zhao and ZY Soa[u Qinghaosu(OHS), a l s o knowaas a r t e m i s i n i n e and art.eannuin, i s i s o l a t o d from the Chinese herb Artemisia annua L. It is highly a c t i v e a g a i n s t both c h l o t o q u i n e - s e n s i t i v e and c h l o r o q u i n e - r e s i s t a n t s t r a i n s of P. berghei amd has been approved by the H i n i s t r y of Health for the treatment of malaria, k~en OHS i s t r e a t e d with sodium dihydroqinghaosu (DHOHS) i s r e s u l t e d with the a c t i v i t y enhanced several f o l d . This paper pharmacokinetics of DHQHS studied with the method.

borohydride, antbslarial r e p o r t s t he

radioimmuneassay

t~hen the drug was given o r a l l y in t a b l e t s form to r a b b i t s a t doses of I0, 20. and 30 mg/kg, peak serum l e v e l s of 0.03, 0.05 and 0.13 ~g/ml r e s p e c t i v e l y ~ere obtained in 1 to 2 h. The corresponding TI/2 of of the drng was fotmd to be 1.19, 1.DO and 1.10 h and the MRTs were 1.73, 1.36 and 1.53 h. No s i g n i f i c a n t difference, b e t ~ e n dosages used was observed. ~)hen dogs was given BHQHS t a b l e t s a t the dose of 20 mg/kg, a peak serum concentration of 0.13 pg/ml was reached in about 2 h with a T1/2 of 2.10 h and a MRT of 3.04 h. However, when dogs were given OHS t a b l e t s a t the dose of 70 mg/kg, no drug was detected in the serum. I t ~vould appear t h a t the b i o a v a i l a b i l i t y of DHOHS t a b l e t s i s much higher than t h a t of Otis when given o r a l l y to the dog. ~ s t i t u t e of Materia Mediea, Sciences, Beijing 100050

URINE EXCRETION RATE AND PROLACTIN-LOWERING EFFECT OF CABERGOLINE, A NEW DOPAMINE AGONIST, IN HYPERPROLACTINEMIC PATIENTS E. Pianezzola, V. Bellotti, M. Strolin Benedetti, G. Gerevini*, C. F e r r a r J ; ~, D. Sghcdoni and N.g. Jannuzzo Cabergoline (C) induces long-lasting prolactin (P) inhibition both in healthy volunteers and in hyperprolactinemic patients (A.E. Pontiroli et el., Br.J.Clin. Pharmaool., 23, aSS, 1987; C. Ferrari et al., J.Clin.Endocrinol.Metab., 6_~$, 9el, 1986). The objective of this study was to collect information on the pharmacokinetics of this compound in hyperprolactinemic patients and to measure in parallel its effect in lowering P. 6 women have been studied up to now; the clinical diagnosis was microprolactinoma in S patients, idiopathic hyperprolactinemia in 1 and empty sella syndrome in g. Serum P levels, determined by RIA before C administration were lOOt18 ng/ml (mean• Three patients took 1 mg C, two 0.5 mg and one 0.78 mg. Urinary excretion rate of C was estimated by collecting urine for a total period of 168 h, determining the concentration of the drug in the urine of the individual collection periods by HPLC with electrochemical detection, calculating the amount excreted in each period and dividing the amount excreted by the collection time. Urinary excretion rates plotted against the midpoints of the urine collection periods, allowed us to calculate elimination half-life (t~). t~ of C ranged from 6 2 t o 91 h. The percent of drug excreted in 168 h urine was 0.7• C induced a marked and long-lasting fall in serum P (gof5 ng/ml at 168 h). Plasma kinetics of both C and major metabolites are necessary to establish suitable correlations between pharmacokinetic parameters and pharmacological effect. ~tEndoorine Unit, Fatebenefratelli Hospital, 20121 Milan Farmitalia Carlo Erba, Research and Development - Erbamont Group, Via Imbonati 24 - 20159 Milan (ITALY).

Chinese

Academy of

Medical

PHARMACOKINETICS OF ~R-RU 38 486 AFTER A SINGLE ORAL ADMINISTRATION OF A 600 MG DOSE

D. TREMBLAY*, R.C. GAILLARD**, p. SAUDAN**, C. COUSTY* and B. LENFANT* RU 38 486 (RU 486-Mifepristone INN) is a synthetic steroid antiprogestln used in the termination of early human pregnancy. AIM OF THE STUDY : TO study the pharmacokinetics of RU 38 486 and 3 m e t a b o ~ e s after oral administration of 'H-RU 38 486 at the reco~ended dose for clinical use. METHOD : 4 fasting healthy female volunteers aged 20 to 33 were given a single 600 mg 55.2 ~.Ci oral dose of 3H-RU 38 486 at the end of a menstrual cycle. Pregnancy was excluded before treatment. Blood samples and urine were co]lected from 0 to 240 h and faeces up to 264 h. Radioactivity was measured by liquid scintillation, after combustion in the case of faeces. The specific activity of urinary water was measured. RU 38 486 and 3 metabolites, RU 42 633 monodemethylated, RU 42 848 didemethylated, RU 42 698 hydro- xylated previously identified in rat and monkey and synthesized were assayed by HPLC. RESULTS : Less than 1 % of tritium was found as tritiated water; 9.2 + i.i (M + SEE) and 83.1 + 1.9 % of the dose were excreted by urine and faeces respectively. The plasma pharmaeokinetic parameters were the following : RU 38 486

RU 42 633

RU 42 848

RU 42 698

(]max ~mol/l 5.43 + 0.49 4.76 + 0.22 2.45 + 0.32 1.34 + 0.16 Tmax h 1.25 + 0.32 3.00 + 0.58 14.00 ~ 3.46 5.00 ~ 1.00 AUC h.;Jmol/l 176 + 24 250 u 31 192 + 43 65 u ii T~ h 24.5 + 2.4 28.1 + 3.3 25.1 u 3.6 21.6 7 1.3 The elimination phase, slow at first, became more rapid at latter time points. T~ was calculated with the last time points by log linear regression when concentrations appeared to decrease as a straight line on a semi log plot. The sum of concentrations of assayed products in plasma was more than 80 % of radioactivity from 0.5 to 12 h. The sum of AUC's was 76 % of AUC radioactivity. CONCLUSION : The biological stability of the labelling was g ~ Excretion of radioactivity was almost complete. Products assayed in plasma represented nearly all circulating products. * ROUSSEL UCLAF Romainville (93230), FRANCE. ** Hopital Cantonal Geneva (CH 1211), SWITZERLAND.

A 314

PP 14.58

PP 14.60

EVALUATION OF A PHARMACOKINETIC CONTROL SYSTEM FOR CYCLOSPORIN DOSAGE ADJUSTMENT. hA Niven< AWKelman, B Whiting~ CA Howie and JD Briggs. A standard Bayesian parameter estimation program underpredicts cyclosporin concentrations after renal transplantation. This may be due to a gradual decline in the clearance/bioavailability (CI/F) ratio. The change has now been incorporated into the Bayesian program and the influence of this modification tested against the standard approach where CI/F is assumed to be constant. The comparison has been made with both one and two compartment models. Data from 18 renal transplant patients were used. Cyclosp0rin was administered orally once a day and blood samples collected twice a week from each patient for the first six weeks. Cyclosporin concentrations were assayed in whole blood using a specific radioimmunoassay. Bayesian parameters were estimated using data from the first 2 weeks and were used to predict concentrations in weeks 3 and 4 (Time A) and 5 and 6 (Time B). The predictive performance of each model was assessed by calculating prediction errors (pe). Mean predictien errors were used to assess accuracy (Table I): precision was assessed by calculating the standard deviation of the mean prediction error (Table 2). Table i. mean (~s.d.) Table 2. mean (~s.d.) Model Time A Time B Time A Time B ] 62.7 ~ 54.7 ]04.1 ~ 58.7 44.7 ~ 33.6 47.7 ~ 23.9 2 12.4 ~ 53.2 24.5 ~ 47.6 35.2 ~ ~3.9 46.5 ~ 17.9 3 72.8 ~ 57.2 111.5 ~ 61.2 40.6 ~ 33.4 48.6 ~ 24.7 4 14.7 + 50.9 44.8 ~ 59.2 40.4 • 32.9 45.7 ~ 21.5 Note Model I, one compartment (constant CI/F) Model 2, one compartment (changing CI/F) Model 3, two compartment (constant CI/F) Mode] 4, two compartment (changing CI/F) In conclusion, the modified program, on average, reduces bias (Friedman ANOVA, p<0.01) but precision is not ~mproved. Department of Materia Medica, Stobhill General Hospital, Glasgow, G21 3UW, Scotland.

DOSE LINEARITY OF B U N A Z O S I N CONTROLLED RELEASE TABLET, A N E W ~ I - B L O C K A D E IN H E A L T H Y C A U C A S I A N VOLUNTEERS . N. Morishita. Y. Tomono, P. S a l m o n Bunazosin (B) is known to be intensively m e t a b o l i z e d in e x p e r i m e n t a l animals. The a b s o l u t e bioavailability of bunazosin in m a n is n o t studied, s i n c e an i n t r a v e n o u s f o r m of b u n a z o s i n has not been developed. In d o s e - f i n d i n g s t u d i e s on oral b u n a z o s i n c o n t r o l l e d - r e l e a s e t a b l e t s (CR) in J a p a n and Europe, it w a s found that the o p t i m a l dose range of C R was f r o m 3 mg to 18 mg. T h e r e f o r e , we s t u d i e d d o s e - l i n e a r i t y of CR 3, 6, 12, a n d 18 mg. M~thod$: Twelve healthy volunteers received CR a f t e r breakfast, in the o r d e r 3, 6, 12, and 18 mg w i t h 1-week w a s h - o u t periods. C o n c e n t r a t i o n s of B in the p l a s m a w e r e m e a s u r e d b y H P L C method. Results: The main pharmacokinetic parameters (mean -+ S.D.) are l i s t e d below:

Conclusion: The plasma concentrations of bunazosin at all d o s e s d e c l i n e d in an a p p a r e n t mono-exponential manner. The mean apparent t e r m i n a l e l i m i n a t i o n h a l f - l i v e s b e i n g 10.7, 12.0, 9.9 a n d 9.5 h o u r s for d o s e s of 3, 6, 12 a n d 18 mg, respectively, and were dose-independent. There was a linear correlation between the administered d o s e a n d the m e a n A U C of b u n a z o s i n in the plasma. S e c t i o n of C l i n i c a l P h a r m a c o l o g y , E i s a i Co., Ltd. K o i s h i k a w a 4-6-10, Bunkyo-ku, Tokyo, 112 Japan.

PP 14.59

PP 14.61

DISTRIBUTION OF I . V . GIVEN THIOPENTAL, I T S INFLUENCE BY AN ANESTHESIA WITH HALOTHANE, ENFLURANE OR ISOFLURANE U. BOche . P. A l t m a y e r * . J . C h . I s e n b e r ~ and H . P . BOth A s t u d y i n man has shown t h a t t h e e a r l y d i s t r i b u t i o n phase o o f t h i o p e n t a l ( T ) was changed by an a n e s t h e s i a w i t h 0 . 8 - 1 . 2 v o l Z h a l o t h a n e ( H ) but not with 0.6-1.2 volz enflurane (E) or 0.91.5 volZ isoflurane (I); each a n e s t h e t i c was a p p l i e d i n c o m b i n a t i o n w i t h 70 v o l S NzO (P. Altmayer et al., A c t a A n a e s t h e s i o l . Scand. 31, 756,1987). In order to study that difference under more s t a n d a r d i z e d c o n d i t i o n s as i n man animal e x p e r i m e n t s were p e r f o r m e d . S p o n t a n e o u s l y b r e a t h i n g W i e t a r r a t s ( w e i g h i n g a b o u t 200 g ) were a n e s t h e t i z e d by i n h a l a t i o n o f 1 . 5 v o l ~ H, 2 . 5 v o l Z E o r 2 . 0 v o l S I ( e a c h 1 . 2 5 MAC) i n a i r for 1 h. Immediately prior to the i.v. injection o f T ( 3 0 m g / k g ) t h e r a t s were t r a c h e o t o m i z e d f o r a r t i f i c i a l r e s p i r a t i o n . R a t s without inhalation a n e s t h e s i a r e c e i v e d t h e same dose o f T and breathed spontaneously (control). Concentration o f T i n t h e serum ( 1 . 5 , 3 , 6 , 1 0 , 3 0 B i n ) was e s t i mated a f t e r e x t r a c t i o n and TLC by UV l i g h t photometrically. I n rate aneethetized with H as w e l l as i n those anesthetized w i t h E or I c o n c e n t r a t i o n o f T d u r i n g 10 min a f t e r i n j e c t i o n was much h i g h e r ( a t l e a s t >37~, m a x i m a l l y >70~) as in the control. Nonlinear regression analysis o f t h e concentration o f T ( u p to 10 m i n ) revealed the f o l l o w i n g equations of the distribution: c o n t r o l ct = 5 7 . 3 - e - ~ 1 7 6 Hct = 76.I-e-0. ~ E ct = 8 9 . 0 - e - ~ 1 7 6 I ct = 8 4 , 5 - e - o - o s z 3 - t . These e q u a t i o n s p r o v e well that i n animal e x perimente using equieffective concentrations of the volatile a n e s t h e t i c s ( 1 . 2 5 MAC) E and I a l s o influence the early distribution phase o o f i . v . given thiopental. Institut f o r P h a r m a k o l o g i e und T o x i k o l o g i e , I n s t i t u t f o r An~sthesie*, U n i v e r s i t a t des S a e r l a n d e e , 0 - 6 6 5 0 H o m b u r g / S a a r , FRG.

P H A R M A C O K I N E T I C P R O F I L E S OF BUNAZOSIN, A N E W ~ I BLOCKADE, AND ITS C O N T R O L L E D R E L E A S E TABLET. J. H a s e g a w a , Y. Tomono. M. Mihara, N. Morishit~zj_ A. O h n i s h i The pharmacokinetics of b u n a z o s i n (B) 6 mg controlled-release tablet (CR) compared with t h a t of 2 m g s u g a r - c o a t e d t a b l e t (C), a n d t h e e f f e c t of f o o d on the p l a s m a c o n c e n t r a t i o n s of B a f t e r CR a d m i n i s t r a t i o n w e r e studied. M e t h o d s : T w e l v e h e a l t h y v o l u n t e e r s r e c e i v e d one C a f t e r b r e a k f a s t , one CR a f t e r b r e a k f a s t or one CR in a f a s t i n g condition in a r a n d o m i z e d crossover study with one-week intervals. The plasma and urine concentrations of B, a n d t h e s e r u m p r o t e i n b i n d i n g w e r e measured. Results: The main pharmacokinetic parameters (mean • S.D.) were:

3 mq 6 mg 12 mq Cmax 5.1• i.i 15.5-+ 4.3 29.4• Tmax 4.8• 1.8 3.9-+ 0.3 4.2• AUC 70.6• 156.0-+46.5 3 2 4 . 3 • tl/2 10.7• 4.9 12.0-+ 4.4 9.9• Cmax: (ng/ml) , Tmax: (hr) , AUC: (ngXhr/ml)

18 mg 38.6+ 16.4 4.8+ 1.4 463.9• 3.4 9.5• 2.8 , tl/2 : (hr) 7.4 0.6

C(after meal) CR(after meal) CR(fastin~) C m a x (ng/ml) 22.5 • 8.3 10.2 • 3.8 11.4 • 4.6 Tmax (hr) 1.0 -+ 0.5 5.3 • 1.9 6.0 • 1.2 A U C (ng• 54.7 • 132.7 • 123.0 • R.B.I) (%) -3) 81.1 • 74.1 • M D T 2) (hr) -3) 10.4 • 2.4 10.2 9 2.4 i): R e l a t i v e b i o a v a i l a b i l i t y c o m p a r e d to C. 2): M e a n d i s s o l u t i o n time calculated assuming that M D T of C was equal to zero. 3): Not a p p l i c a b l e . The m e a n a p p a r e n t t o t a l p l a s m a clearance, renal c l e a r a n c e and p l a s m a h a l f life a f t e r C. w e r e 11.4 • 4.8 m l / m i n / k g , 0.149 • 0.054 ml/min/kg and 1.23 • 0.30 hr, respectively. The unbound f r a c t i o n in the p l a s m a was 0.029 • 0.0075. Conclusion: T h e s e d a t a s u g g e s t t h a t C R is a r e l i a b l e o n c e - a - d a y f o r m u l a t i o n of B. S e c t i o n of C l i n i c a l P h a r m a c o l o g y , Eisai Co.,Ltd. K o i s h i k a w a 4 - 6 - 1 0 , B u n k y o - k u , T o k y o , ll2 Japan.

A 315

PP 14.62

PP 14.64

PHARMACOKINETICS OF FK366 AND ITS EFFECTS ON ALDOSE REDUCTASE AND SERUM URIC ACID IN HEALTHY VOLUNTEERS M. Kanamaru, A. Mizuno, S. Nagashima, T. Uematsu, M. Nakashima, M. Terakawa and A. Su$iyama In an early stage study in volunteers, FK366, a new aldose reductase (AR)inhibiter showed uricosuric activity. To confirm this finding, and to investigate the pharmacokinetics and AR inhibition in more detail, we performed a study in healthy male volunteers given a single oral dose of 150, 300 or 600mg of FK366 after fasting, 600mg after'eating, or 300mg ql2h after eating. The AR inhibition was assessed by % reduction from the pre-dose values of red cell dulcitol converted from exogenous galactose by AR. The pharmacokinetics of FK366 were linear: respective mean (SD) Cmax in the fasting subjects were 22.6(8.1), 39.0(7.3) and 75.7(25.6) mcg/ml 0.9, 1.6 and 2.7 hr after dosing with 150, 300 and 600mg; AUC increased in proportion to the dose; ti%2~ and urinary recovery were not dose-dependent and averaged 8.2 (1.2) hr and 27(9)% of the dose, respectively. After 600mg in the fed state, Cmax and AUC decreased by 45 and 29%, respectively, compared with those in a fasting state. By repeated dosing, plasma FK366 levels reached steady state by day 2, with Cmax of 15.1(4.3) mcg/ml after the first dose and 17.5(5.2) mcg/ml after the last dose. AR inhibition paralleled the increase of plasma FK366, with maximum inhibition of 31.6(10.0), 48.0(9.7) and 56.9(7.4)% for 150, 300 and 600mg, respectively. This inhibition did not differ between the first dose (41.8%) and last dose (41.5%). Serum uric acid decreased dose-dependently with the minimum concentration of 4.0mg% (pre-dose: 5.5mg%) attained 8 hr after 600mg. By repeated dosing, serum uric acid levels declined rapidly and became steady from day 3 onward, whereas the urinary levels were high on day I. In conelusion, FK366 was confirmed to have linear pharmacckinetics, and AR inhibition and uricosuric activities in man. Department of Pharmacology, Hamamatsu University School of Medicine, 3600, Handa-cho, Hamamatsu, Japan.

PHARMACOKINETICS OF ZINC ACEXAMATEAFTER SINGLEORAL ADMINISTRATION IN HEALTHY VOLUNTEERS S. Sendr6s, E. Jim~nez, C. Vernetta and J.L. Galm6s Zinc acexamate (ZAC) is a new antiulcerous drug with cytoprotective and antisecretory actions. Moreover, zinc represents the second trace element after iron in relation to its amount in man. Zinc compounds present a very low bioavailability due to their homeostatic regulation in the organism. We compared the pharmacokinetlcs of ZAC p.o. in two doses: 188.0 mg (=30 ag of 2n) and 313.0 mg (=50 mg of Zinc) in 6 healthy male volunteers with a mean age of 21.7• years and a mean weight of 74.7~Ii.4 kg. The circadian rhythm of their basal z i n c levels was previously studied. Furthermore the volunteers took part in two other additional t r i a l s (one for each dose), in a randomly assigned order at 7 day intervals. The samples of blood were collected at: O, 0.5, I, 1.5, 2, 3, 4, 6 and 8 hours and urinary samples at O, 2.5, 5, 7.5, I0, 15 and 24 hours after taking ZAC capsules or without medication in the basal period, always at the same chronological time. Plasma and urine zlnc concentrations were measured by atomic absorption spectrophotometry. Basal plasma zinc concentrations were f i l l e d at one trigonometric (sin or cos) or lineal function (r > 0.53) (n=5 and i respectively). Plasma zinc after ZAC administration was f i l l e d at the biexponential function C=A e-KaE-c e-KsIs according to the RIP programme, assuming that the o , o , . . absorptlon and ehmlnatlon processes of ZAC obey an one f l r s t order kinetics and that a single constant defines each one of the processes. The next table shews the pharmacokinetic parameters estimates:

PP 14.63

PP 14.65

PHARNACOKINEI'ICSANDDISPOSITIONOF PIC[NAST IN HUMANS A. Wittenbrink-Dix, E. gesenfe]der, P. Neubert and G.Neugebauer Pharmacokinetics of the a n t i a ] l ergic cc~npound pict~nast (p) and i t s active metabolites M1 and M2 were studied in 10 healthy v o l u n t e e r s a f t e r a s i n g l e oral dose of 2Umg p dihydrochloride. Concentration of p, M1 and M2 were assayed by HPLC coupled t o a f l u o r o m e t r i c detector. Non-compartimental k i n e t i c evaluation was performed by means of the programpackage Kinpak. Picumast M] M2 AUC[ngxh/ml] 1752 1200 701 Cmax[ng/ml] 130 2] 14 tmax [h] 3.2 3.4 4.0

PHARMACOKINETICS OF FENOFIBRATE AFTER REPEATED ORAL DOSES IN MAN R. Levy-Prades Sauron +. J.P. Guichard +. J.J. Th~bault ++ and H_ Capla~n ++ The absorption of fenofibrate (F), a major lipid lowering drug, is enhanced by food. A previous multipledose study had been performed but F was administered in fasting conditions. The objective of this study was therefore to evaluate the pharmacokinetics of fenofibric acid (FA), the active metabolite of F, after repeated oral doses of F administered with food according to the usual dosage regimen (i00 mg t.i.d.). M e t h o d : 18 normal volunteers (9 males + 9 females) received during a standard meal one capsule 1 0 0 m g F on day 1 with blood specimens collected over 120 h. Subjects were then given I00 mg F with food three times daily (8h-12h-20h) for 10 days (day 6 to day 15). Several blood samples were collected during this period. On day 16, subjects received a single 100 mg F dose during the same meal as in day 1 with blood samples collected over the following 120 hours. FA was measured by liquid chromatography. Results : Steady-state was reached 8 days (before administration of day 14) after the beginning of the multiple dose-regimen. The apparent elimination halflife is not modified after multiple dosing (23 h after first dose and 23.7 h after last dose). However, the accumulation is higher than expected since AUC0_24 at steady-state (day 14 and day 15) normalized to a i00 mg dose is significantly higher than AUC~ after the first i00 mg dose (about 40 %). This accumulation is probably due to a better absorption of F during the multiple dosing phase than after the first single reference dose, related to a higher dietary fat content during the multiple dose phase than in the standard breakfast taken with the single reference dose. + Laboratoires Fournier, Centre de Recherche de Daix, 50 rue de Dijon, 21121 Fontaine-l~s Dijon, France ++ ASTER, H6pital Cognacq-Jay, 15 rue Eug&ne Millon, 75015 Paris, France

tl/2 [h] CIR[ml/min]

25.9 b.d.

41.1 28

33.6 0.5

median; b.d. = urin6~concentration below detection limit (2 nglm]) The metabolic ~spositJon of p was studied in 3 elderly |malthy subjects after oral administration of 14C-labelled drug. The concentration of radioactivity was determined in plasma, urine and faeces by liquid scintillation spectrometry. P was also determined in plasma by HPLC. The half-life of radioactivity in plasma ranged from 46 to 9lh, tl/2 for p was determined as 55-56 h. At 1.5 h p.a. 49% of radioactivity was represented by p, and 25% by the inactive rretabo]ite M4. Ml and M2 concentrations were below the detection limit of the assay. Up to 57% of the dose was excreted in urine in form of metabMites and only less than 0.3% unchanged. Within 24 h 61~83% of radioactivity excreted in urine consisted of oxidized forms like M] (7-]8%), M3 (10-]8%), M2 (below 3%) cleavage products like M4 (3-6%) and of glucuronide conjugates (ca. 40%), mainly those of M4. 23-32% of the dose was revovered in the faeces. Boehringer Mannheim GmbH, Klinische Pharmakologie, Sandhofer Str. 116, D-6800 Mannheim 31

PERIOD

ZAC 188 mg ZAC 313 mg

Cma~ (mgl-')

Tmax (h)

1.51 • 0.27 I.g3 • 0.29

2.70 • 0.80 2.90 • 0.80

AUCI Ao (mgl- h) (mgl- I ) 11.54 • 1.00 13.00 • 2.26

2.01 • 1.05 3.80 • 3.21

(h~ ) 0.$2 f 0.08 0.60 i 0.12

CoI (mgl-)

Ke (h- i )

2.g3 f 0.17 o.g8 0.00 4.24 • 0.18 • 2.13 0.06

The urinary elimination of zinc was very low both before and after taking supplementary doses of zinc (ZAC).

Oepartamento de Investigaci&n Cl[nica. Laboratorios Viflas, S.A. Torreate Vidalet, 29 OSOl2-Barcelona, Spain.

A 316

PP 14.66

PP 14.68

KEIOROL.RC TR,qNSFER (K"I) IlY'IO CSF,

TOLERANCE AND PHARMACOKINETICSOF CAMOSTATMESYLATE (FOY305) IN NORMALHUMANSUBJECTSAFTER SINGLE RISING INTRAVENOUS INFUSION DOSES. T. J. Forrest, T. Taylor, L. F. Chasseaud, S. R. Irons, P. F. Salmon and R. Bonn. The synthetic protease i n h i b i t o r , FOY-305, was continously infused intravenously to 6 subjects at rates of 0.5 mg/h for 4 h, 1.0 mg/h for 4 h and 1.5 mg/h for 4 h and then at 72-h intervals at 3 mg/h, 4.2 mg/h and 5.0 mg/h, each f o r 12 h. Two other subjects were administered placebo, FOY305 was generally w e l l - t o l e r a t e d during and a f t e r . i n f u s i o n at each dosage l e v e l , there were no detected systematic changes in v i t a l signs. There were no c l i n i c a l l y relevant changes in ECG rhythm, morphology or interval data, or in haematopoietic, hepatic or renal function during or a f t e r administration of FOY-305 at each dosage level. Measurements of pulmonary FEV7, FVC, FEVI/FVC ratios and peak expiratory volumes wer# within nomal l i m i t s and there were no detected systematic changes in prothrombin times, APTT, thrombin c l o t t i n g times, euglobin c l o t l y s i s times, ~-2 antiplasmin and antithrombin I I { a c t i v i t i e s or f i b r i n ogen levels. The in v i t r o h a l f - l i f e of FOY-305 (a diester) in plasma~as a l min and i t was undetectable (<25 ng/ml) in a l l plasma samples taken; however, two metabolites, FOY-251 and guanidinobenzoic acid (GBA), could be measured by HPLC. Both exhibited apparently linear pharmacokinetics a f t e r infusion of F0u with plasma AUC and Cmax of each increasing in a similar r a t i o to the increasing dose of FOY-305. The systemic clearances (395 and 288 ml/min), volumes of d i s t r i b u t i o n (V(area), 28 and 59 l i t r e s ) and terminal h a l f - l i v e s (ca. 0.8 and 2.3 h) of FOY-251 and GBA respectively were apparently independent of the dose of FOY-305 administered. Department of Metabolism and Pharmacokinetics, Huntingdon Research Centre, Huntingdon, PEI8 6ES, England.

~L~..__9..'..~u.t_t_~y_a._n_L_.g.S_.C._. R~c.e.z_,_C._..M_JJ_t..er',.-L,__.L.!o#__ &:.[~:_=&:.._B_4.U:.tn,~.h_~n~ Studies ii'i arlima.ls demonstrate that K"I is a potent anatgesic, anti-irfl:lammatory and anti--pyretic agent. KT is a cyclo-oxygenase i n h i b i t o r alqd pain r e l i e f ' with this type of acjent involves the peripheral rather than the central nervous system. This is supported by the fact that KF does not exh:ibit the side elq:ects c l a s s i c a l l y associated with c e n t r a l l y acting drugs. Cerebro-spinal l:luid (CSF) l:)enetration oi: KT may however s t i l l occur and the aim crF this Study was to measure, following :intramuscular (IM) inject:ion, the trans[-'er of-' KT into the CSF. Ten patients undergoing e l e c t i v e s under spinal anaesthesia 14ere studied. Between 60 and 90 rains be f'ore the anticipated s t a r t of' surgery and the patients wer'e given 90 mg I
PP 14.67

PP 14.69

PHARMACOKINETICS OF THE NEW SERENIC ELTOPRAZINE IN MAN Lvan Harten, and M.Raghoebar.

PHARMACOKINETICS OF XIMOPROFEN AND ITS METABOLITES IN HUMAN SUBJECTS.

= ~ = = : = : : =

= : : = : ~ = : :

:

=

=

:

=

=

:

=

=

~

:

~

:

Eltoprazine hydrochloride (DU 28853) is a compound belonging to a new class of psychoactive drugs, serenics, which selectively inhibits offensive behaviour in animals, while leaving social and defensive behaviour intact [1,2]. In order to establish the pharmacokinetics of eltopraziue in man, the drug was administered orally (8 mg) and intravenously (2,9 mg and 7.7 rag; l-hour infusion) to 12 healthy male subjects. After i.v. administration (2.9 rag) the elimination half-life was 74-3 hours, systemic plasma clearance 2264-124 ml,h-l.kg -1, and steady-state volume of distribution 3.34-0,7 l,kg -t, Cumulative urinary excretion was 434-12%, These pharmacokinetic parameters were not significantly different after i.v, dosing of 7,7 mg. After oral administration, mean maximal plasma levels of 244-6 ng.m1-1 were reached after 2.3 & 1.| hours, The terminal half-life of eltoprazine was 10:1:4 hours, Systemic availability was almost 10O%, Eltnprazine was well tolerated at this dose range in healthy subjects, Dosedependent somnolence was observed, and other complaints were minor and of uncertain drug relationship. Blood pressure, pulse rate and ECG were unaffected. Duphar B.V., Drug Disposition Department, P.O.Box 2, 1380 AA Weesp, The Netherlands. [1] Olivier B, Van Dalen D, Hartog J. Drugs Future 1986; 11: 473-494. [2] Olivier B, Mos J, Stress Med 1986; 2: 197-209,

T. Taylor, L. F. Chasseaud, B. Patterson, D. Assinder, L. M. Walmsley and G. Dorf. The pharmacokinetics of the new anti-inflammatory agent ximoprofen and i t s metabolites ketoximoprofen and hydroxyximoprofen has been studied a f t e r intravenous and oral doses (115 ~moles; 30 mg) to normal human subjects. Ximoprofen was characterised as a drug of almost complete systemic a v a i l a b i l i t y (92%), r e l a t i v e l y low systemic and renal clearance (1.5 and 0.2 ml/min/kg), small volume of d i s t r i b u t i o n (V(area) 0.24 I/kg; V(SS) 0.18 I/kg) and r e l a t i v e l y short terminal h a l f - l i f e ( I . 8 h), the l a t t e r being similar a f t e r intravenous and oral doses. After oral doses, ximoprofen was r a p i d l y absorbed with an absorption h a l f - l i f e of ca. 20 min. A 2-compartment open model adequately described the intravenous plasma drug level data. Ximoprofen did not strongly i n t e r a c t with peripheral tissues. The plasma protein-binding of ximoprofen was ca. 90%-95%. The terminal h a l f - l i f e of ketoximoprofen (2.1 h) was similar to that of the parent drug. Enzyme-hydrolysab!e conjugates of ximoprefen or i t s metabo l i t e s were not detected in plasma a f t e r intravenous or oral doses. In urine a f t e r intravenous doses, 12% of the dose was excreted as unconjugated ximoprofen, 3% as ketoximoprofen and 2% as hydroxyximoprofen, and 40%, 16% and 6% as conjugates of these compounds respectively. After intravenous doses, ca. 80% of the dose was excreted as t o t a l drug-related material, mostly in conjugated form. This was similar a f t e r oral doses. Excretion of the major ximoprofen metabolites was apparently r a t e - l i m i t e d by t h e i r formation from the parent drug. Department of Metabolism and Pharmacokinetics, Huntingdon Research Centre, Huntingdon, PEI8 6ES, England.

A 317

PP 14.70

PP 14.72

2-MEREAPTOPROPIONYLGLYCINE (2-MPG) IN THE TREATMENT OF

A P P L Y I N G S Y S T E M A P P R O A C H TO N O N L I N E A R P H A R M A C O K I N E T I C S OF THE O R G A N I C C A T I O N T H I A M I N W e b e r W, H a r n i s c h L, L o o b u M and N i t z M C r u c i a l for a p p l y i n g s y s t e m a p p r o a c h is to k n o w whether the disposition kinetics is linear, i.e. f o l l o w s the superposition principle with r e s p e c t to d r u g input, or is n o n l i n e a r . To t e s t for s u p e r p o s i t i o n , we a d m i n i s t e r e d 5, i0, 50, i00, a n d 200 m g t h i a m i n h y d r o c h l o r i d e e i t h e r as i v - b o l u s o v e r 2 min, or as 50 m i n iv-infusion to 12 v o l u n t e e r s . B e s i d e s d o s e dependency, we e x a m i n e d the effect of renal efficiency on system parameters by including 4 patients with pathological k i d n e y function. The f i t t i n g p r o c e d u r e of p l a s m a d a t a i n v o l v e d the c o n v o l u t i o n of the c h a r a c t e r i s t i c u n i t i m p u l s e response, a three exponential function, and the d r u g i n p u t function, a r e c t a n g u l a r P u l s e of l e n g t h 2 or 50 min. The r e c i p r o c a l v a l u e of the a r e a u n d e r the unit impulse r e s p o n s e f u n c t i o n w a s d e f i n e d as total b o d y c l e a r a n c e Cl = I/AUC(6). A m u l t i p l e nonlinear regression analysis was performed either with total b o d y c l e a r a n c e , or w i t h the renally excreted f r a c t i o n of d o s e A(e) as dependent variable, and a p p l i e d dose D t o g e t h e r with creatinine clearance as independent variables. Using CI(R) = i0 C l ( c r e a ) ^ 0 . 8 for renal clearance and CI(NR) = 9 4 5 / ( I + ( D / 2 9 ) z) for n o n r e n a l c l e a r a n c e , t o t a l body clearance was c a l c u l a t e d b y Cl = CI(R) + CI(NR) and the renally excreted fraction of d o s e b y A(e) = CI(R)/CI. While the renal clearance was not d o s e dependent, nonrenal clearance was. Its v a l u e d e c l i n e d f r o m 920 m l / m i n at 5 m g to less than 20 m l / m i n at 200 mg, i n d i c a t i n g a n o n l i n e a r d i s p o s i t i o n k i n e t i c s for thiamin. Institut for K l i n i s c h e P h a r m a k o l o g i e , K l i n i k u m Steglitz, H i n d e n b u r g d a m m 30, D - 1 0 0 0 B e r l i n 45

EYSIINURIA - A PHARMAEOKINETIC BACKGROUND B-M.Emanuelsson, M.Carlsson, T.Oennerberg, B.K&gedal and S.Lindgren 2 MPG is used in the treatment of cystinuria, an inherTted metabolic disease characterized by increased excretion of eystine. Impaired reabsorbtion in the renal tubuli and thereby high concentrations of cystine which has low solubility, explains the recurrent formation of urinary stones. The mechanism of activity is a replacement of one of the eystein residues in the cystine molecules with 2-MPG, resulting in a mixed disulphide with higher solubility and reduced stone formation. The basic pharmacokinetics of 2-MPG is however unknown. In this study 10 healthy volunteers received 250 mg 2-MPG as an i.v. bolus dose and 500 mg as an oral dose. Blood and urine samples were collected, and total and nonprotein bound plasma concentrations of 2-MPG were estimated. Most of the drug was rapidly eliminated with 75 % of the given dose excreted unchanged in the urine, mainly during the first 6 h after the administration. A small fraction although remained in the body and resulted in a terminal t I 9 of 55 + 11 h. The V was estimated to 99 + 27 1 s~B the bi~avaJlabilityS~o 60 s 24 Z. The nonprotein bound fraction of 2-MPG increased in a nonlinear manner with increasing total plasma concentration of 2-MPG, with a maximal value oF 94 + 2 %. Two types of bindings may be involved, a eonvenTial plasma proteinbinding and covalent bound disulphide bridges. The covalent binding is formed between 2-MPG and avaiiable sulphur on either low molecular entities like cystine and gluthathione or high weight molecules like albumine. Departments of Hospital Pharmacy, Nephrology and Clinical Chemistry, University Hospital, 5-581 83 tink6ping, Sweden

PP 14.71

PP 14.73

PHARMACOKINETICS AND BIOAVAILABILITY OF KETOPROFEN AFTER INTRAVENOUS, INTRAMUSCULAR AND ORAL ADMINISTRATION G. Montay, A. Le Lib oux, D. Chassard, J.J. Th6bault, A.~Frydman, J. G a i l l o t (Rh6ne-Poulenc Sant~, Antony and IREB, Paris, France) The pharmacokinetics (blood and urine) bioavailability and tolerance of ketoprofen (a non-steroidal anti-inflammatory drug belonging to the group of a r y l - 2 - p r o p i o n i c acid d e r i v a t i v e s ) a f t e r intravenous ( i v ) , intramuscular (im) and oral (pc) dosing were determined in 15 young healthy male subjects randomly receiving a single 100 mg dose (cross-over design). Plasma f r e e non conjugated and t o t a l u r i n a r y ( f r e e plus conjugated) ketoprofen was determined using an hplc method. Results were as follows f o r iv/im/po (m + sd) dosing r e s p e c t i v e l y : AUCo_, (~g.h.ml - I ) = 25753 + 6.09, 22.28 • 7.33, 26.44 • 5.55 ; t 1/2 el (h) = 2.05 • 0.39, 2.08 + 0.29, 2.17 + 0.33 ; Ae (% o f dose in urine) : 69.25 + 11.3, 62.40 + 14.64, 67.75 + 11.75. Therefore, t h e - o v e r a l l absolute b i o a v a i l a b T l i t y o f ketoprofen a f t e r im and pc route was r e s p e c t i v e l y about 90 and 100 %. In r e l a t i o n to the analgesic e f f e c t o f ketoprofen, the r a t e o f drug absorption is of i n t e r e s t : the maximal concentration was the same f o r both im and pc administration, i . e . 11.31 • 3.43 and 12.15 + 3.75 ~g/ml r e s p e c t i v e l y . However the time to reach t h i s concentration was s i g n i f i c a n t l y d i f f e r e n t , i . e . shorter f o r the im route : 0.33 h (range : 0.25 0.83 h), in comparison to the oral route : i h (range : 0.50 - 1.50 h) ; t h i s d i f f e r e n c e , which corresponds to d i f f e r e n c e in mean absorption time (MATpo = 1.32 h vs MATim : 0.49 h), is the main f a c t o r in the r a t i o n a l e basis f o r the therapeutic use of im ketoprofen in acute pain treatment of inflammatory diseases. Rh6ns Poulenc Sant~ - IBP - 20, Avenue R. Aron F-92165 Antony Cedex - France.

PHARMACOKINETICS OF 14C-trans-SOBREROL IN THE HEALTHY VOLUNTEER F. Luzzani~ M. A. Girometta, P. Ventura, S. Canali *, C. Giachetti *, G. Zsnolo * trans-Sobrerol (SOB) is a drug widely used for the treatment of respiratory diseases with bronchial mucus hypersecretion and obstruction. The aim of this study was to compare absorption and elimination of the radioactivity with those of the unchanged compound after a single oral administration of 14C-SOB (300 mg, 2.4 MBq) to six male healthy volunteers in order to obtain quantitative information about the fate of this drug. The radipactivity in plasma, urine and faeces was assayed by liquid scintillation counting either directly (in the case of plasma and urine) or after combustion using a sample oxidizer (as in faeces). The unchangsd 50B was analyzed by capillary GLC. The main pharmaeokinetic parameters were estimated using non compartmental method. The drug was rapidly absorbed and extensively metabolized as suggested by a very different pharmaeokinetie profile between radioactivity and unchanged drug: Cmax were 10.8 pg eq/ml vs 3.2 #g/m], AUC were 121.9 h-pg eq/ml vs 8.0 htpg/ml, MRT were 23.1 vs 2.8 h. The radioactivity was excreted largely by renal route (94Z of the dose) and negligibly by faecal route (1.4%). The unchanged SOB in urine accounted for ca 1% of the administered dose. This clearly indicates that the majority of the absorbed dose was eliminated as metabolites. Camillo Corvi S.p.A. Res. Labs. 1-29]00 Piacenza and 9Biomed.Res.lnst. R.B.M. I-lOOlO Colleretto Giacosa (TO) - Italy

A

318

PP 14.74

PP 14.76

PHARMACOKINETICSOF Z O L P I D E M A S A FUNCTION OF GENDER C. Dubruc, J.P. Th~not, P. Rosen, G. Bianchetti and P.L. Morselli In a preliminary study conducted with i0 women and i0 men, it appeared that the pharmacokinetic profile of zolpidem, StilnoxR, a sleep inducer from the imidazopyridine family, was influenced by gender (AUC and Cmax higher in ~ than in ~ ) . However, due to the limited number of subjects it was not possible to draw a definitive conclusion. The influence of gender was so investigated in a larger population after single oral a~inistration of 20 mg of zolpidem in young and i0 mg in elderly (35 young ~ , 69 young ~ , 23 elderly ( > 65 years) ~ and 12 elderly ~ ). Considering young subjects a sex difference was observed for the dose dependant pharmacokinetic parameters (AUC1 , Cmax I ) but not for Trnax and TI/2 (see table). Normalizing the values by the body weight (dose/kg) the observed differences became not statistically significant (see table Cmax 2, AUC2). These results were even more evident in case of elderly subjects. It was,on the contrary,confirmed, as previously observed} a pharmacokinetic difference linked to the age. These results indicate that there is no need for a lower dose for women, but confirm the necessity of a reduced posology for elderly.

HEMODYNAMICS EFFECTS OF A 62-ADRENOCEPTOR AGONIST, CLENBUTEROL. IT'S CONSEQUENCE ON HEPATIC BLOOD FLOW. M.C..Rubio, L. Masnatta. Acute Clenbuterol administration (50 ~g/kg, i.v.) to anesthetized normotensive rats, produced a marked reduction in the mean blood pressure (about 58 mmHg). Indocyanine green clearance analysis showed that the action in the hepatic vascular bed is opposite to its systemics vasodilator effects (control:_l 1'43 -+ 0.15, clenbuterol: i.i + 0.20 ml x rain x i00 g- , p < 0.05). The hepatic blood flow (HBF) appears significantly reduced -i (control: 8.24 + 0.35; C l e n b u t e r o l : 3 . 8 3 + 0.71'ml x min x I00 g-l, p < f . o s ) . Rifampin (hepatic high extraction drug) and phenytoin (hepatic low extraction drug) clearances were analyzated to corroborate our findings. After 60 mg/kg, ip administration of Rifampin, a significant reduction in clearance was observed _qcontrol:• 290 --+ 13-, clenbuterol 130 _+ 13 ml x min x kg , p < 0.05), according to a marked reduction in the elimination const a ~ (Ke), (control: 0.34 ~ O.02;clenbuterol: 0.18 ~ 0.02 Hr ). However, after I0 mg/kg i.v. administration of Phenytoin, no changes in the clear,nee (control: 226 25; clenbuterol: 277 ~ 28 ml x min x kg~ I) and in the elimination constant (control: 0.23 ! 0.03, c!enbuterol: O.19 + 0.02 Hr ) were observed. In conclusion, the present results, have shown a marked reduction in HBF (which would be produced by a redistribution flow phenomena) follows systemic vasodilator effects produced by clenbuterol. Biopharmacy. School of Pharmacy and Biochemistry. Univ. Buenos Aires. Junfn 956. (ii13). Instituto de Farmacolog f a y Toxicologfa. LAPLEX S.A. Buenos Aires. Argentina.

IWeight ICmaxl I AUC 1 ICmax2 [~UC---~----(kg) ( n g / m ~ (ng/ml) I(ng/ml.h) I(ng/ml)

I

I

WOMEN( < 65y)

.

.

.

.

.

56~14

340~31

1264~88

1037_+107 3512_+248

.ff_ L

.

WOMEN

159+2,3 1199+16

(( > 65y)

--

1874+81

~i142~Ii015277+712

-11. --33 181 152

1159_+2025962_+1123

SYNTHELABO RECH~CHE (L.E.R.S.) - 23-25, Saulnier 92366 MEUDON-LA-FORET CEDEX (F)

av.

Morane

PP 14.75 ROSAPROSTOL SERUM ORAL MULTIPLE DOSE G. Giorgi~ A.I. Fiaschi,

PP 14.77 KINETICS IN VOLUNTEERS ADMINISTRATION

AFTER

G. Segre

Rosaprostol, prostaglandin-like molecule with gastric eitoprotective activity, is the active c o m p o u n d contained in Rosal launched in Italy b y I.B.L Giovanni Lorenzini S.p.A. Milano. In 12 healthy volunteers after 4 oral administrations of 1 g Rosaprostol, the concentration time-course in serum was determined at the following times (rain): 90, 180, 270, 330, 390, 450, 1440. The drug was administered immediately after blood collection at the following times (rain): O, 90, 180, 270. The method used to determine the serum levels of t h e drug is that described by Segre et aL (I). The oral pharmacokinetics after multiple dosing was performed on the basis of previously studied parameters and the compartmental model was that described (i). The serum kinetics are equal to X(t) = 4.2 e "~

1

+ 0 . 4 0 e "~176- 4.6 e "~

being X = pg/ml and t = hours. T h e s e r u m p e a k l e v e l s of R o s a p r o s t o l w a s of 2.5 j u g / m l a b o u t a t 5-6 h o u r . Following t h i s e x p e r i m e n t a l d e s i g n , t h e s e r u m l e v e l s of R o s a p r o s t o l a r e 5 t i m e s h i g h e r t h a n a f t e r 5 0 0 mg s i n g l e o r a l d o s e a d m i n i s t r a t i o n (1). References 1) S e g r e , G., F i a s c h i , A. I., Bianchi, E., Ciani, D., T e d e s c h i , S. (1988) A r z n e i m . - F o r s c h . / D r u g Res. 38, 1846-1849. I s t i t u t o di F a r m a c o l o g i a , U n i v e r s i t A S c o t t e 6, 53100 Siena, I t a l y .

di

Siena,

Via

dene

RENAL SECRETION OF 3'AZIDO-3'DEOXYTHYMIDINE (ZIDOVUDINE, AZT) IN R A T S A N D R A B B I T S J.-Y. C h a t t o n , D. Mosiq, K. B e s s e q h i r and F. Roch-Ram@l Renal excretion of AZT (drug u s e d in A I D S treatment) was investigated in a n e s t h e t i z e d rats by measuring AZT and inulin urinary c l e a r a n c e s (C~T and C~nul). A t the t h e r a p e u t i c p l a s m a c o n c e n t r a t i o n s (PAzT) of 5 pM, o r at PAZT of 160 ~M, A Z T f r a c t i o n a l e x c r e t i o n s (CA~/Cinu]) w e r e 2.7 • 0.1 and 2.6 • 0.1 r e s p e c t i v e l y , indicating net renal secretion. S i n c e at pH 7.4, 9 9 . 5 % of A Z T is p r e s e n t in the f o r m of an o r g a n i c cation, A Z T s h o u l d be s e c r e t e d by the proximal organic cation secretory mechanism. A Z T b a s o l a t e r a l s t e p of t r a n s p o r t was f u r t h e r i n v e s t i g a t e d in v i t r o in i s o l a t e d n o n p e r f u s e d rabbit proximal tubular segments ($2 s e g m e n t s ) . C e l l u l a r c o n c e n t r a t i o n of A Z T w a s c o m p a r e d to that of i n c u b a t i o n m e d i u m (C/M), w h e n t u b u l a r s e g m e n t s w e r e i n c u b a t e d d u r i n g 30 m i n w i t h 4 p M A Z T in the a b s e n c e (control) or the p r e s e n c e of 10 -4 M p o t e n t i a l i n h i b i t o r s of secretion. In control, C / M was 29 • 2 (n=26), d a t a d e m o n s t r a t i n g a c t i v e t r a n s p o r t . C / M was d e c r e a s e d by 48% in the p r e s e n c e of 10 -4 M mepiperphenidol (classical inhibitor of organic cation secretion). Unexpectedly, 10 -4 M p r o b e n e c i d or p-aminohippurate (two o r g a n i c anions) a l s o i n h i b i t e d c e l l u p t a k e by 55%, A Z T a p p e a r s t h e r e f o r e to be s e c r e t e d by b o t h the o r g a n i c c a t , o n and a n i o n t r a n s p o r t systems. I n s t i t u t de P h a r m a c o l o g i c de l ' U n i v e r s i t ~ de Lausanne, Bugnon 27, CH-I005 Lausanne, Switzerland

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SYSTEMIC ABSORPTION OF TOPICALLY APPLIED OCULAR SCOPOLAMINE IN PATIENTS R. Huupponen, T. Kaila, K. Lahdes~ L. Salminen, E. Iisalo Despite of the wide-spread use of scopolamine (S) in ophthalmology there are no reports about its systemic absorption from eye drops. Both atropine (Lahdes et al, Clin.Pharmacol.Ther. 1988; 43:310) and Cyclopentolate (Kaila et al, Am.J.Ophthalmol.,in press) are rapidly absorbed after ocular administration in man. We therefore undertook a study concerning the systemic absorbtion of S. Sixteen patients received one 40 pl drop of 0.25 % S or placebo in randomized order to the lower cul-de-sac of one eye. Plasma S concentrations were quantitated by a sensitive radioreceptor assay up to 90 minutes. Blood pressure, heart rate and salivary secretion were monitored to evaluate systemic drug effects. The drug absorption in the S group (n=8) was rapid; the mean plasma S concentration after 3 minutes was 400+150 pg/ml. It was decreased to ii0~70 pg/ml at 90 minutes. The peak S concentration of 540~200 pg/ml was reached within 15 minutes (range from 3 to 15 min) in 7 patients. In one patient, however, S peaked first at 30 minutes (280 pg/ml). Ocular S did not affect patients" blood pressure or heart rate when compared with those of the placebo group. Thirty minutes after administration of S eyedrops, the salivary secretion was slightly but nonsignificantly reduced in the S group. Departments of Clinical Pharmacology, Pharmacology and Ophthalmology, University of Turku, Kiinamyllynk,10, SF-20520 Turku, Finland.

PHARMACOKINETICS AND TOLERABILITY IN H E A L T H Y E L D E R L Y V O L U N T E E R S

K.M. BGker, G. Peter, H. RiethmGller-Winzen, K. Junqe and H.O. Borbe Azelastine (AZE), 4-(4-chlorobenzyl)-2-(hexahydro-l-methyl-iH-azepine-4-yl)-l(2H)-phthalazinone HCI, is a novel orally effective antiallergic and antiasthmatic drug. The pharmacokinetic parameters and tolerability of AZE were investigated in 15 healthy elderly volunteers (9 m; 6 f) following single or multiple doses (b.i.d.) of 4.4 mg AZE. Plasma concentrations of AZE were determined by RIA. After single doses (multiple doses), maximal plasma levels were found at 7.1 (6.7) h to be 2.9 (19.1) ng-Eq./ml. AUC(0-~) was calculated with 174.5 (AUC(f): 198.8) ng-Eq.h/ml and t h e terminal half-life with 38.5 (55.4) h. The ratio of accumulation was calculated from plasma levels at 12 h after the Ist and 14th dose with 6.4. A c c u m u l a t i o n is due to the dosing interval (12 h) and prolonged half-life presumably to co-detection of the long-living, pharmacologically active N-desmethyl-metabolite by the RIA. The parameters showed relatively high inter-individual variation. As compared to youngs in the elderly all pharm a c o k i n e t i c parameters increased slightly. Overall, tolerance following single and multiple dosing proved to be very good. In conclusion, no dose reduction has to be recommended, for AZE in long-term asthma therapy. The risk of an underdosage seems to be higher, than a potential risk of poorer tolerability. A S T A Pharma AG, Dept. Biochem./Clin. Pharmacol. Weism~llerstr. 45, D-6000 Frankfurt, FRG

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PHARMACOKINETIC STUDY OF A NEW SUSTAINED-RELEASE THEOPHYLLINE FORMULATION IN PATIENTS WITH OBSTRUCTIVE

AZELASTINE OF A NOVEL

PNEUMOPATHY

H. Riethm~ller-Winzen, K. Junge, K.M. B~ker, G. Peter and H.O. Borbe Azelastine (AZE), 4-(4-chlorobenzyl)-2-(hexahydro-l-methyl-iH-azepine-4-yl)-l(2H)-phthalazinone HCI, is a novel orally effective antiallergic and antiasthmatic drug. The pharmacokinetic parameters and tolerability of AZE were investigated in 12 healthy young volunteers (6 m; 6 f). Plasma concentration of AZE following a single oral dose (4.4 mg) were determined by RIA. At 5.1 ~ 1.4 h maximal plasma levels were found to be 3.3 • 0;9 ng-Eq./ml. AUC(0-~) was calculated with 93.7 • 27.7 ng-Eq.h/ml and the terminal half-life with 22.2 • 4.5 h. Dose linearity could be demonstrated for single oral doses of 2.2, 4.4, 8.8 and 17.6 mg of AZE. The values of AUC(0-~) and Cmax increased linear to the dose, whereas tmax and terminal half-life of elimination remained unchanged. They showed relatively high inter- and somewhat less intra-individual variation. This is most likely due to a varying degree of ,enterohepatic circulation resulting from alimentation factors. Due to the co-detection of AZE and the p h a r m a c o l o g i c a l l y active m e t a b o l i t e of AZE, N-desmethyl-AZE , by RIA, the parameters describe the pharmacokinetic behaviour of the active principle. Overall, tolerance proved to be very good indep e n d e n t l y from the dosages administered. AZE was found to possess a broad therapeutic range, wide enough to recommend 4.4 mg b.i.d. or single doses of 8.8 m g / d a y for therapy in adult patients. A S T A Pharma AG, Dept. Biochem./Clin. Pharmacol. WeismHllerstr. 45, D-6000 Frankfurt, FRG

D. Cova. G. Cuglituri. L. Rossini and IV Medical Dept. (Head: G. Borromeo General Hospital, Milano. Italy. Two

O. Bonfardeci

Bonfardeci), via Pio II

S. 3,

Carlo 20155

different doses of a sustained-release tablet of theophylline were administred to two groups of patients affected by chronic obstructive pulmonary disease. Pharmacokinetic parameters were determined after a single administration of the drug; in this experiment the theophylline plasma levels were determined 1.2,4.8.12 and 24 hours after the drug administration. In another experiment, the patients received the drug "once-daily", in the morning, for nine consecutive d a y s . Plasma theophylline levels were monitored 24 hours after the first administration and twice daily on day 3, day 6 and day 9. Patients receiving 700 mg/day showed theophylline levels ranging from 8.49 • 1.04 ~g/ml to 20.99 • 2.09 wg/ml. In this group theophylline concentrations were found to be >I0 pg/ml also 24 hours after the tablets administration. These data show that in case of single daily theophylline administration an high dosage is necessary to mantain the drug concentration within the range of therapeutic levels. formulation

OF AZELASTINE

- PHARMACOKINETICSAND TOLERABILITY ANTIASTHMATIC DRUG IN MAN

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AN OPEN PILOT STUDY OF STIRIPENTOL IN THE TREATMENT OF COMPLEX PARTIAL SEIZURES UNCONTROLLED BY CARBAMAZEPINE O. Rascol (1), G. Houin (2), J. Tor (3), H. Blehaut3-(~ A. Rascol4-O-),J.L. Montastmd~-L~_

THE UPTAKE OF GLUTAMATEAND ASPARTATEBY PLATELETS IN MYOCLONUS EPILEPSY M. M. Airaksinen and T. Ker~nen Blood p l a t e l e t s have been used as models for CNS neurons, p a r t i c u l a r l y in neurotransmitter uptake studies. A decrease in the uptake of 5-HT has been found in endogenous depression (Tuomisto & al: Psychopharmacology 65:141-7, 1979) and in that of taurine in r e t i n i t i s pigmentosa (Airaksinen & a l : Lancet I: 474-5, 1979). The e x c i t a t o r y amino acids glutamate and aspartate also have an active uptake by p l a t e l e t s (Mangano and Schwarcz: J Neurochem 36: 1067-76, 1981). We have studied the p l a t e l e t uptake of these amino acids in patients with the B a l t i c type of myoclonus epilepsy (ME). The p l a t e l e t - r i c h plasma of the patients was obtained from Vaajasalo Hospital. The normal controls belonged to the personnel of our laboratory. P l a t e l e t - r i c h plasma was incubated in buffer with H3-1abelled amino acids + various concentrations of c a r r i e r for 30 min, following p r i n c i pally e a r l i e r methods (Mangano and Schwarcz: J Neurochem 36:1067-76, 1981). The incubation was ended by rapid membrane f i l t r a t i o n rather than centrifugation~ The p l a t e l e t s of the ME patients took up aspartate less a c t i v e l y but glutamate s i m i l a r l y or s l i g h t l y more a c t i v e l y than those of the controls. The difference in aspartate uptake seemed to be in Vmax rather than in Km. A decrease of uptake would mean an increased concentration in the synaptic c l e f t . At least the effect of glutamate is ended by an uptake to the g l i a l c e l l s rather than neurons and i t remains to beshown i f the p l a t e l e t s are a good model for g l i a . The patients had long-lasting a n t i e p i l e p t i c treatment (usually valprotate or combinations), and the changes in the uptake could be due to the drugs or to the desease. However, the aspartate uptake in ME seemed to be lower than in s i m i l a r l y treated other e p i l e p t i c s .

Stidpentol {4,4- dimethyl-I-[3,4-(methylenedioxy)-phenyl]-1-penten-3-ol } (STP) is a new drug from the family of aromatic aUylic alcohols which presents anticonvulsivant activity in animal models o f epilepsy. It also inhibits cytochrome P450 activity. Seven patients (5 males, 2 females, mean age 49 -+ 6 years, mean duration of epilepsy 25 + 8 years), all suffering from complex partial epilepsy according to the revised clinical and electroencephalographic classification of epileptic seizures (1981) entered this open study. During the 2 months preceding the study, the mean frequency of seizures was 12.9 + 4.2/month while patients were treated with an optimal mean dose of Ct~Z (700 + 49 mg/day) (mean plasma levels = 6.0 -+ 1.3 mg/1). 5 patients were also treated with phenobarbital and 3 with valproic acid. When entering the study, CBZ dosage was reduced of one third (mean dose 486 + 60 mg/day) and STP was added at the dose of i500 mg/day. The mean seizure frequency (assessed monthly with a daily calendar) significantly decreased from baseline (12.9 +- 4.2/month) to 3.9 + 0.6/month (month 1), 5.9 -+ 1.9Anonth (month 2), 4.4 -+ 3.4/month (month 3) and 2.7 + 1.0/month (month 4 ) (p < 0.05 at every month, non parametic Wilcoxon signed rank test). Plasma levels of CBZ did not significantly vary in spite of dosage reduction.Adverse effects were few and of mild intensity.One patient reported transient irritability and two others transient somnolence. One patient related the appearance of action tremor.No change in routine biological tests were observed. These preliminary open data suggest a potential antiepileptic efficacy of STP which can be explained by a direct anticonvulsivant activity and/or pharrnacokinetie interactions with other classical antiepileptic drugs. These phase II results have to be confirmed by placebo controlled trials. Services de Pharmacologie M6dicale et Clinique,INSERM U317 (1), de Pharmacocin&ique Clinique (2), de Neurologie(4) CHU et Facult6 de M6decine Toulouse et Laboratoires Biocodex, Montrouge.(3), F]L~NCE .

Department of Pharmacology and Toxicology, University of Kuopio, P.O.Box 6, SF-70211Kuopio, Finland

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THE EFFICACY AND FREQUENCYOF TOXICITY AFTER A BOLUS PHENYTOIN DOSE IN THE TREATMENTOF STATUS EPILEPTICUS J. R. Snyman The effectiveness of phenytoin therapy in the acute treatment of epilepsy is established (8.J. Wilder, Adv. Neurol. 34, 441, 1983). Patients in status epilepticus present with acute neurological disorders, hypoxia and high-neuronal energy consumption leading to enzyme malfunction and metabolic abnormalities (A. V DelgadoEsweta, New. Eng. J. Med. 306, 22, 1337, 1982). The present study was undertaken to ascertain the efficacy and frequency of phenytoin t o x i c i t y a f t e r the administration of a bolus infusion in the acute care setting. The following protocol was implemented: Patients in status epilepticus received a 18 mg/kg phenytoin infusion at a rate of 50 mg/min a f t e r which blood for phenytion plasma levels was taken at 30~ 60, 240, 480 and 720 minutes. Patients were monitored for another 12 hours a f t e r infusion and the frequency and duration of seizures, signs of t o x i c i t y and other metabolic d i s t u r bances were plotted against time. Of the twelve patients who met the c r i t e r i a only two did not respond to treatment. Eleven reached t o x i c plasma phenytoin levels (above 20 mg/l). Plasma levels dropped to within therapeutic l i m i t s in only f i v e patients during the 12 hour observation period. Although six patients showed overt cerebellar signs these were not c l i n i c a l l y s i g n i f i c a n t . These signs disappeared a f t e r bolus infusion at higher plasma phenytoin levels than previously described with chronic treatment (H. Kutt, Ann. N.Y. Acad. Sci., 179, 704, 1971). The mean bloodpressure of nine patients dropped s i g n i f i c a n t l y (p
THE UPTAKE OF GLUTAMATEAND ASPARTATEBY PLATELETS IN PATIENTS WITH AMYOTROPHICLATERAL SCLEROSIS T. Ker~nen and M. M. Airaksinen Blood p l a t e l e t s have been used as a model for CNS aminergic neurons and t h e i r function has been studied in many neurological disorders (Stahl: Arch Gen Psych 34:509-16, 1977). Uptake processes for amino acid transmitters, such as for GABA and taurine (Airaksinen: Epilepsia 30:503-I0, 1979), and recently, for glutamate and aspartate have been described (Mangano and Schwarcz: J Neurochem 36:1067-76, 1981). Amyotrophic l a t e r a l sclerosis (ALS) is a degerative neurological disorder in which altered glutamate and aspartate metabolism has been observed. We studied the p l a t e l e t uptake of these amino acids in patients with an established diagnosis of ALS. The p l a t e l e t - r i c h plasma of the patients and that of the healthy controls was incubated in buffer with H3-1abelled amino acids + various concentrations of the c a r r i e r for 30 min according to the methods previously described (J Neurochem 36:1067-76, 1981). The incubation was stopped by rapid membrane f i l t r a t i o n rather than centrifugation. The uptake of glutamate and aspartate by p l a t e l e t s was similar both in patients and in controls. Our preliminary results suggest that an impaired uptake of glutamate or aspartate may not be involved in the pathogenesis of ALS. Department of Pharmacology and Toxicology, University of Kuopio, P.O.Box 6, SF-70211Kuopio, Finland

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DOUBLE-BLIND TRIAL OF L-THREONINE IN AMYOTROPHIC LATERAL SCLEROSIS: A PRELIMINARY STUDY

PLATELET SEROTONIN (SHT) AND TRYPTOP~N OF NORMAL VOL~'IEKKS AND PSY61{IAT~IC PATIENTS

O. Blin* r G. Serratrice* t J. Pouqet* r G. Aubrespy**, C. Guelton*~ A. Cravat**

Although the cause of Amyotrophic Lateral Sclerosis remains unknown, ALS may relate to a defect in the excitatory neurotoxicamino acids metabolism. To neutralize these abnormalities, it has been suggested to use L-Threonine which administration increases Glycine (an inhibitory amino acid) in the central nervous system. In an open preliminary trial LThreonine was sho~n to reduce ALS symptoms within 48 hours in some patients. These considerations led us to confirm in a double blind, cross over random• placebo-controlled trial the usefulness of a 7-day 9 tratment with L-Threonine (2g/day) for patients with ALS. 12 patients, with early stage ALS were entered into the study. Neurological ratings included a manual testing (sum of i0 muscles power rates), a quantitative gait analysis, a dynamometric grip strength evaluation (Grip Strength Mediscus), a bulbar score derived from TQNE and a self evaluation by analogue visual scales. All the two treatments were well tolerated. The objective neurological ratings produced the following results. The grip strength (p<0.05) and manual testing (p<0.05) were improved by L-Threonine compared to placebo. The subjective ratings of treatment effectiveness, measured on the basis of visual analogue scales, showed better effectiveness of L-Threonine than placebo (p
C.H. Tan~ H.S. Lee and A. Hsu The roles of plasma 5HT and tryptophan in psychiatric illnesses remain controversial. Since the blood platelets have many features similar with 5HT neurons, we report here the platelet 5HT and tryptophan concentration of normal volunteers, untreated and treated patients. Platelets were isolated from the studied subjects who had fasted and had taken no NSAIDs or paracetamol for a period of 2 wee~s. Platelet concentration were normalized to 2 x 10~ for all the analysis. 5HT and tryptophan were estimated using HPLC with EC detector. Platelet 5HT rig/m1 Normal untreatedpsychiatric treated psychiatric Volunteer patients patients N--15 N=-2 N=3 ........................................................ meantSEM 147 • 8.3* 202.5 • 47.4 203 • 11.2" range i01 - 222 155 - 250 182 - 220 ........................................................ Platelet tryptophan ng/ml Normal t~itreatedpsychiatric treated psychiatric vol~teer patients patients N=-I5 N=2 N=3 ........................................................ mean• 205 • 12.9 555 • 14.9"* 162 • 14.7 range 140 - 346 540 - 570 140 - 190 ........................................................ * p < 0.005 ** value higher than treated and normal v o l u n t e e r s p < 0.005, p < 0.0001 Although the number of patients studied were few, the preliminary data showed that the platelet 5HT were significantly lower in the 15 normal volunteers than the treated psychiatric p a t i e n t s (p < 0.005). Platelet tryptophan was significantly higher in the untreated patients than treated and volunteers (p < 0.005, p < O.0001). Department of Pharmacology, National University of Singapore, I0 Kent Ridge Crescent, Singapore 0511.

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IN VIVO BRAIN KINETICS OF 11C-5-HYDROXITRYPTOPHANE AND 11C-I-DOPA IN HUMANS VISUALIZED WITH POSITRON EMISSION TOMOGRAPHY,PET? P.Hartvig, H Agren,L Reibring,J Hetta,J Tedroff,H.Lundqvist,P Sjurling,J Ulin and B L~ngstrSm.

VINPOCETiI~ TREATI~NT OF CEreBRAL II~ARCT!ONS STI~IED BY CO~IPUTED TOI[OGP~Ph~ P.Kalvach, J.Vymazal,Jr. and J.Baue r ~ourty patients with clinical and CT evidence of cerebral infarction in acute stage have been derided into two groups:Twenty patients of the first group(13 males,7 females,average age 58,7 years) were treated with Vinpocetine 20 mg/day in drop infusion and after one week orally 3xlO mg/day.Twenty patients of the second group(14n~ales,6 females,average age 43,8 years) were treated with either Aethophyllin 400-800 mg/day or Xanthinol nicotinate 300-600 mg/day parenterslly during the first week and orally in following weeksoTwo CT e x a m i n a t i o n s in each patient have been evaluated.The first one done during the f i r s t l O d a y s a n d t h e s e c o n d o n e b e t w e e n t h e 20. and 50.day after the stroke.All patients were examined in plain scans as well as after aoplication of 1 ml Diatrizoate(290 mg iodine)per ~g body w~ght intravenously. Three par~neters have been studied: extension o f t h e l e s i o n intensity of h y p o d e n s i t y presence/intensity of post-contrast enhancem~qt The proportion of v o l u m e c h a n g e s of the infarcts@ area between the first ~Id second examinat i o n i n terms o f " d e o r e a s e d " ~ " n o t - o h ~ u ~ e d " and ' i n c r e a s e d " h a s b e e n fotuld i n t h e V i n o o c e t i n e gretlp I I : 6 : 3 , i n comparison t o 9 : 8 : 2 i n t h e n o n Vinpoeetine group(l patient not considered due to h e m o r r h a g e into malacia). The degree of tissue hypodensity,as a sign of me~atic deterioration,increased in the Vinpocetine group 12x,whereas in the control group 15x. The third criterion did not bring any explicit criteria~ Deoartment of Neurolegy,~aculty Hospital,~har!es University,~fate~inskl 3 0 , 1 2 0 O 0 P r ~ h a 2 , C S Z R

Positron emission tomography,PET, is a noninvasive tracer technique which measures the kinetics of a positron emitting exogenous or endogenous compond in the tissue of the living human. The technique has been used to measure the kinetics of drug in the effect organ; the distribution of drugs in the spinal canal or from mother to fetus; the formation of transmitter and the binding characteristics of receptor ligands to selective receptors. The method has also found wide-spread applications in the study of particular receptor populations in health and disease. So far, the found changes in dopamine receptor binding in diseases such as schizophrenia and Parkinson's disease have been minor. The turn-over in the brain of neurotransmitters of importance for the development of psychiatric diseases has been in focus for many years. We have recently got the opportunity to study the utilization in the brain of two neurotransmitters, since the precursors of serotonine and dopamine, i.e. 5-hydroxitryptophane and l-dopa,labelled with 11C, have become available. The selective brain utilization of the tracers has been measured after different pretreatments,and in one patient with depressive disorder before and during treatment. The selective utilization of 11C-l-dopa increased in the brain with simultaneous administration of mg-amounts of unlabelled l-dopa, while a decreased uptake of 5-hydroxitryptophane was seen in the brain together with unlabelled fdr~g ~ . Pretreatment with peripheral decarboxylas inhibitor increased selective brain utilization of both tracers. A parallel localization of both tracers in the brain was obvious and PET to a large extent quantitates the activity of aromatic decarboxylase. During treatment with chloroimipramin,brain utilization of 5-hydroxytryptophane increased. Hospital Pharmacy,University hospital,75~85 Uppsala,Sweden

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NIMODIPINE F O R TARDIVE DYSKINESIA IN ELDERLY PATIENTS

A MULTICENTER STUDY ON DIETARY ~

N. Brlon. J . Gailledreau, C. D u c r e u z e t , M.H. M a r i o n

ACIn~ AhD LONG-TERM EFFECTS P. Martalletti, G. Busscne, V. Centonze, A. Ferrari, F. Fredieni, D. Magrone, G. Micieli, L.A. Pini, A.P. Verri end M. Giacovazzo Some foods contain a wide variety of allergenic determinants 1~at are able to provoke headache by release of neur~vasoactive substances (E.C. Hu~nes, Ann. Allergy 55, 28, 1985). Cromolyn sodiL~l (CS) was fotnd to prevent histanine release fran mast cells (R.N. Brogden, Drugs 7, 164, 1974). Trigger foods of migraine crises were identified by chsller~es in 56 migraine patients. Twenty-four of 1~em were studied for the acute effect of CS after a standsrdized challenge, carried out weekly for one month. Only the first end last cballengas ccme 30 minutes first CS intake at the dose of 2000 ~ . The Total Pain Index (TPI) showed a significant decrease on headache ~cores following the challenges protected with C$ in coRpsrison with the unprotected ones (p< .CO1). The Drug Consumption Index (DCI) in treated patients showed a paralleled diminution of daily eclalgesic drug eonsL~ption only between the first and the the third challenges (p< .05). In the other 32 migraine patients wc s~udied the lor~-te~ cffect~ of ~ . Tr~ ~ia! w ~ cc~ricd cut fop ~0 days and challenges were performed at the first day and after every 20 days using standard quantities of provoking foods. CS intBke was 900 mg daily for 60 days. TPI scores showed a prograssive significant decrease of headache crises during the period of trial with CS (p< .001) and DCI confirmed this trend (p <.005). Interestingly, a positive carry-over phenomenon by CS treatment was observed durir~ ~ne last 20 days drug-free of the trial. The block by CS of the mediators release involved in food~related migraine physiopathology could be based on the inhibition of the IgE-mediated hypersensitivity end of the i~mme complexes production (J. M~Y~., Lancet 2, 719, 1984). Headache Centres of Rove , Bari & Modena Universities, and of Neurological Institutes "C. Besta", Milan & "C. Mcndino", Pavia, Italy. Medical Pathology, University "La Sspienza", Viale del Policlinico, 00161 Rome, Italy

Tardive dyskinesia are a serious complication of t r e a t m e n t with neuroleptics, Several t r e a t m e n t s for tardive dyskinesia have been proposed b u t none h a s been consistently successful, Some a u t h o r s reported the reduction of abnormal movement in one patient treated with verapamfl and three patients treated by diltiazem. We have treated Six patients ( 6 w o m e n aged between 77 to 85, m e a n 79.6 years) with nimodipine 30 mg three times a day. All of t h e m presented with neuroleptic induced dyskinesia. The evaluation of t r e a t m e n t efficiency was clinical, It consisted in recording patients on videotape before and after treatment. All the sequences of the videotape were randomly mixted. 22 physicians were asked to determine which was the sequence before or after treatment for each patient. Two patients improved ( the order of the sequences was recon~ed by 20 of the 22 physicians for one and 1 4 / 2 2 for the other) . The place of calcium channel blockers in the t r e a t m e n t of tardive dysklnesia w a r r a n t s further investigation. D e p a r t m e n t of Clinical P h a r m a c o l o g y . Centre Hospitalier de Versailles. 177 rue de Versailles. 78156 Le Chesnay Cedex. I:~.am~".

HEADAQ~ ASD CROMOLYN SODIUM:

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DOUBLE-BLIND STUDYTO DETERMINETHE EFFICACY AND SAFETY OF DEXFENFLURAMINE IN THE TREATMENTOF OBESITY K.Sriwatanakul, K.Yuthavon9 and S.Komindr In this double-blind clinical t r i a l the efficacy and safety of 15 mg dexfenfluramine given twice daily in the treatment of uncomplicated obesity was comparedwith placebo. The 16 weeks study consisted of a ~ week dietonly run-in period followed by 12 weeks of drug treatment. Fifty-two obese patients (8% males), 120% to 150% of ideal body weight, gave their written consent to participate in the study. Patients were examined before entering the study, after 4 weeks of a diet-only regimen and at weeks 2,4,6,8,10 and 12 on medication. At each v i s i t they were weighed, examined and were asked to rate their feelings of hunger and satiety on visual analog scales. After 2 weeks of treatment, patients in the dexfenfluramine-treated group had lost significantly more weight than with placebo. Highly significant differences were found between the two groups in the various parameters tested. Themean cumulative weight loss in kg, weight loss as percent of i n i t i a l body weight and the Feinstein Reduction Index were 4.9,6.9 and 38.3 for dexfenfluraminegroup compared to 1.6, 2.0 and 12.0 for placebo group respectively. Patients receiving dexfenfluramine reported a significant decrease in hunger and an increase in satiety. In the dexfenfluramine-treated group, significant decreases from the diet-only period in serum levels of cholesterol and t r i g l y c e r i d e s were observed during treatment. No serious side effects were noted in either group. On completion 9f the study, patients on dexfenfluramine were allowed to receive the drug f o r an additional period of three months. The results indicated that they were able to maintain t h e i r weight toss and about 35% kept on losing weight (1 kg or more). I t is thus l i k e l y that dexfenfluramine is a useful adjunct f o r the long term treatment of simple obesity. Department of Pharmacology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.

CEREBROSPINAL-FLUID COPPERLEVELS IN PARKINSON'S DISEASE J. F. Belliveau, G__~,P__~,O'Leary, Jr, and J. H. Friedman A previous study indicated that copper levels in the cerebrospinal-fluid (CSF) of Parkinson's disease patients are elevated (H. S. Pall, et al, Lancet ii,238 1987). This study was undertaken to determine i f these elevated Cu levels are due to the diseased state or drug therapy. Cu, Zn, Fe and Si CSF-levels were simultaneously measured by d-c argon plasma emission spectroscopy. This methodology has less matrix-interferences compared to electrothermal atomic absorption spectroscopy. Calibration standards were matrix-matched. Analytically, high Fe levels, >I00 ng/L, indicated an undesirable amount of serum in the sample. High Si levels, >500 ng/L, and high Zn levels, >200 ng/L, were found in samples stored in glass containers. Only Cu data from samples stored in p l a s t i c and having Fe levels
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IMIPRAMINE AND A SELECTIVE SEROTONIN REUPTAKE INHIBITOR (PAROXETINE) IN THE TREATMENT OF THE 5Yk4~ OF PERIPHERAL DIABETIC NEUROPATHY 5.H. Sindrup, L.F. Gram, O. Esh~ and E. Mogensen The e f f e c t of a s e l e c t i v e s e r o t o n l n reuptake i n h i b i t o r ( p a r o x e t i n e ) on syrqotornetic p e r i p h e r a l d i a b e t i c neuropathy was examined in a d o u b l e - b l i n d c r o s s - o v e r study against imipramine end placebo. On the basis o f previous studies, the doses of imipramine was a j u s t e d to y i e l d optimal plasma l e v e l s o f imipramine plus desipramine of 400-600 nM. P a r o x e t i n e was given as a f i x e d dose o f 40 rro/day. The p a t i e n t s were evaluated by d a i l y s e l f - r e t i n g s and o b s e r v e r - r a t i n g s at the end o f each 2-weeks treatment p e r i o d . The r a t i n g s covered the symptoms pain, p a r e s t h e s i a , dysesthesia, n i g h t l y aggravation and steep disturbance. P r e l i m i n a r y data a n a l y s i s confirmed a substantial r e l i e f in symptoms by imipramine in these pat i e n t s , whereas the e f f e c t o f p a r o x e t i n e was less d e a r . A f t e r the d o u b l e - b l i n d t r i a l , some of the o a t i e n t s were t r e a t e d w i t h imipramine in i n c r e a s i n g doses to e s t a b l i s h a more exact dose-response r e l a t i o n s h i p . This part of the study was s i n g l e - b l i n d and the e f f e c t o f treatment was evaluated by p a t i e n t s ' d a i l y s e l f - r a t i n g s . Preliminary data a n a l y s i s suggested some i n t e r - p a t i e n t v a r i a b i lity in lower e f f e c t i v e drug l e v e l s (imipramine plus desipramine) that might f o r some p a t i e n t s be below the 400-500 nM l i m i t suggested in e a r l i e r s t u d i e s (B. K v i nesdal, J. M~lin, A. Freland, L.F. Gram, JAM& 251, 1727, 1984). Department o f C l i n i c a l Pharrr~cology, (3dense U n i v e r s i t y , J.B. Winsl~ws Vej 19, DK-5000 Odense C.

EFFECTS OF SYSTEMIC ADMINISTRATION OF A SYNTHETIC ACTH (4-9)-ANALOG (HOE 427) ON EVOKED BRAIN POTENTIALS IN H U M A N S W. Kern t H.L. F e h m I R. P i e t r o w s k y t W. Sittig I J. Born Evidence exists that the 4-9/10 - fragment of A C T H m o d u l a t e s c h o l i n e r g i c t r a n s m i s s i o n in b r a i n areas of animals after systemic administration. In humans, ACTH 4-10 has b e e n shown to d i s t i n c t l y affect the Nd c o m p o n e n t of a u d i t o r y evoked b r a i n p o t e n t i a l s (AEP), w h i c h is an i n d i c a t o r of s e l e c t i v i t y of a t t e n t i o n (Born et al., Exp. Brain Res. 67, 85, 1987). The p r e sent s t u d y was d e s i g n e d to c o m p a r e influences of a synthetic ACTH 4 - 9 / 1 0 - a n a l o g (HOE 427: M e t ( O 2 ) - G l u H i s - P h e - D . L y s - P h e - N H - ( C H 2 ) 8 - N H 2 ) on the Nd component in h e a l t h y humans with those of p l a c e b o and of the 410 s e q u e n c e of the e n d o g e n o u s ACTH. F o l l o w i n g an a d j u s t m e n t session each of 20 m e n (2130 yr) w e r e t e s t e d during 4 sessions in a 'dichotic listening' p a r a d i g m a (Hillyard et al., Science 182, 177, 1973) for the d e t e r m i n a t i o n of the Nd component. Forty min prior to testing subjects received iv e i t h e r 200 ~g or 60 Pg of HOE 427, 1 mg of A C T H 4-10 or p l a c e b o a c c o r d i n g to a d o u b l e blind l a t i n - s q u a r e design. AEPs were recorded from m i d l i n e e l e c t r o d e locations (Fz, Cz, Pz). F o l l o w i n g placebo, a distinct f r o n t o c e n t r a l Nd comp o n e n t could be identified in the AEPs (amplitude at Cz: 1 . 1 5 + / - 0 . 2 5 ~V). HOE 427 as w e l l as A C T H 4-10 significantly reduced the Nd. The s t r o n g e s t e f f e c t was o b s e r v e d following 200 ~g of HOE 427 (at Cz: 0.50+/-0.19 pV); the Nd r e d u c t i o n s f o l l o w i n g 60 ~ g HOE 427 (0.85+/-0.24 BY) and f o l l o w i n g 1 m g A C T H 410 (0.77+/-0.23 ~V) appeared to be about equal. The d o s e - d e p e n d e n t reduction of Nd a m p l i t u d e a f t e r HOE 427 t o g e t h e r w i t h the effects of A C T H 4-10 dem o n s t r a t e that these peptides are p o t e n t m o d u l a t o r s of b r a i n functions in humans. The Nd r e d u c t i o n reflecting a diminished s e l e c t i v i t y of a t t e n t i o n m a y be r e l a t e d to effects of the p e p t i d e s on c h o l i n e r g i c transmission. Angewandte Physiologie, Universitat Ulm, 7900 U l m and K l i n i s c h e Forschung, Hoechst AG, 6000 Frankfurt, FRG

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NEFOPAM - CAN IT REPLACE PENTAZOCINE ?

PLASMA R~DUCED HALOPERIDOL LEVELS AND CLINICAL OUTUOME IN S C K I Z O ~ S.Bareggi, R.Cavallaro, M.C.Mauri, M.G. Regazzetti, A.C.Altamura. Department of Pharmacology and Clinical Psychiatry, University of Milan, Italy. Previous studies found a linear or curvilinear r e l a t i o n s h i p between levels of haloperidol (HL) and c l i n i c a l o u t c o m e , o t h e r s d i d not. H o w e v e r , m o s t s t u d i e s d i d n o t e v a l u a t e its a c t i v e m e t a b o l i t e , reduced haloperidol (RHL). A trend to poor response in patients with h i g h RHL p l a s m a levels was p r e v i o u s l y shown. We studied the i n f l u e n c e of p l a s m a HL, RHL levels, and the RHL/HL ratio on clinical outc~re and side effects in 18 schizophrenic patients, aged from 17 to 52 yrs (mean 30.27 + Z.6), diagnosed according to DSM Ill, treated with HL for six weeks. Clinical picture, extrapyramidal and anticholinergic side-effects were assessed by the BPRS, the EPSE and a check list (ACS) before and after 3 and 6 weeks of treatment. HL and RHL were measured by HPLC and GLC-MS on the 3rd week. Plasma HL levels ranged from 1.3 to 16.8 ng/ml (mean 4.94 + 0.87), p l a s m a RHL levels ranged from 0 to 16.8 ng/ml (mean 6.51 + 1.14)j RHL/HL ratio ranged from 0 to 4.3 (mean 1.62 + 0.3). There was n o c o r r e l a t i o n b e t w e e n H L p l a s m a l e v e l s a n d clinical response after 3 and 6 weeks of treatment nor between RHL plasma levels, RHL/HL ratio and clinical o u t c o m e a f t e r 3 w e e k s of t r e a t m e n t . RHL plasma levels, RHL/HL ratio were significantly related with the clinical outcome after 6 weeks (r=-0.64 p<0.01; r=-0.46 p<0.05). There "~as no correlation between HL, RHL, R H L + H L plasma levels and EPSE scores. On the other hand, ACS scores were correlated with HL plasma levels (r=0.75 p <0.01). Thus, RHL influences the response to HL treat/rent in schizophrenia. The reason for this might be that RHL is less active than HL and high c o n c e n t r a t i o n s of this c o m p o u n d in brain might decrease the activity of H L by competing for receptors.

R.J. Jha, B.P. Shah, C.N. Reghu, S.R. Navani, Kirti Patel and V.G. 0ke Worldwide a esnstant search for non-narcotic, effective analgesics is on, due to well-known drawbacks of narcotics. No such new drug ~as, introduced in India during the last decade. We conducted a pre-registration (Pbese-III),double-blind, rsndomised, comparativeevaluation of the non-rmrcotic analgesic - Nefopan (Nrmipan) Vs. Pentezocine, a commonly used narcotic analgesic in Indian patients. Patients satisfying the inclusion criteria (mild to very severe pain, needing an m~igesic) and the standard exclusion criteria for Phase-Ill clinical trials (children, pregnancy, mjor OrS/hepatic/renaldisorders, etc.) were enrolled in the study. Dependingon the initial intensity of pain, they received either Nefopam (30-60mg oral, or 20 ~g I.M.) or Pentazocine (50-100mg oral, or 30 mg I.M.) 6 hourly. Six hourly pain scores, all side effects, results of biochemical investigations pre and post therapy, overall evaluation of therapyboth by patients and investigator was recorded. Statistical analysis of data on continuous variables was done using student's t-test and categorical data by either Fisher's Exact Probebility Test (FEPT) or (hi-squared test. Differenceswere labelled as statistically significant if 2-tailed test gave a P value of less than 0.05. Both drugs reduced pain scores significantly(differencesinsignificant between groups). Side effects were noted in both groups (Nefopam - all mild, in II patients/27occasions and Pentazocine - mild to severe, in 9 patients/24occasions). However, of these, significantly more patients receivingPentazocine had to be withdrawn from the trial due to adverse drug rasction as compared to norm in Nefopam group (p=0.008 : FEP~). Birmhem/calvalues were within physiologicalrange at the and of the study. Response to t~astmest~ s adjudged e~celleat to good in significantly (p=0.046:FEPT)larger number of patients in Nefopam group beth by patients and investigator. Due to esmparable efficacy, favourable safety profile with lesser withdrawals from therapy and overall superior patient and investigator experience, Nefopam appears to be an effective and better replacement to Pantazocinein India. Division of Clinical & Experimental Research, Wsekh~rdt Limited, Poonam Chambers, Dr A.B. Road, Worli, Bombay 400 018. India.

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PP 15.17 TRIAZOLAM

0.25

DOUBLE-BLIND

mg

CROSS

VS OVER

LOPRAZOLAM STUDY

IN

1 mg

: A RANDOMIZED

GENERAL

PRACTICE

FOR

COMMON INSOMNIA. This study compared efficacy and safety of 2 hypnotics BZD with following design: the 2 treatments were administered on the first 2 nights as a cross over trial. After the 2nd night patients have to choose one of the 2 treatments and were continuing a 3 weeks treatment period with the preferred one. In case of no preference they received one of the 2 drugs (new randomization). Results : Among 67 included patients, 65 were fully evaluable for preference. 50 stated clearly their choice (15 had no preference) with 31 patients (47.7 %) preferring Triazolam (T) vs 19 (29.2 %) preferring Loprazolam (h) p=O.09. Significant differences have been found in favour of (T) concerning 3 items on a 7 items scale : Global help to get in sleep (p=O.O16), decrease of night awakenings (p=O.02), feeling to be rested on morning (p=O.O15). The reduction of sleep latency was marginally significant (p=O.07). No difference was observed concerning the last two items (depth and duration of sleep). During 3 weeks follow-up period both drugs improved dramatically quality of sleep whatever the treatment was. Conclusion : T and L are effective in treating outpatients common insomnia. Patients were generally able to diffentiate and to choose the preferred treatment after I intake. It is suggested that one month treatment including a one week tapering period may be an optimal duration of treatment in common insomnia generally avoiding sleep disturbances at treatment stop and BZD dependance problems.

THE EFFECTS OF ALPRAZOLAM,DIAZEPAM AND QUAZEPAMON PSYCHOMOTOR PERFORMANCE IN HEALTHYVOLUNTEERS M. W. Blom, P. R. Barrel, De K. Sommers, C. H. van der Meyden and P. J. Becket This study investigated the effects of a single dose of the abovementioned drugs on a battery of psychomotor and electrophysiological tests. Nine male volunteers participated in a double blind, placebo controlled crossover study. Spectral analysis of the EEG, saccadic eye movements (SEM) and visual analogue scales (VAS) of Bond and Lader were recorded prior to oral drug administration, and repeated 1, 3, 4, 6 and 8 hours later. Critical Flicker Fusion (CFF) and the Sternberg Choice Reaction Time (CRT) were recorded at 1,5 hours after drug ingestion. Wilcoxon signed rank tests were used to determine the statistical significance of the effects of these drugs relative to each other. Diazepam, quazepam and alprazolam showed significant increases in relative slow beta power, while alprazolam compared to quazepam showed significant increases in the relative fast beta power only. Theseincreases were s t i l l significant eight hours after treatment. Significant decreases in peak saccade velocity were observed with each of the three drugs compared to placebo, but not compared to each other and these decreases were s t i l l evident eight hours after treatment. CFF showed a decrease with all three drugs, but attained statistical significance only with alprazolam. An increase of CRT was observed with all three drugs, but attained significance only with alprazolam. An index of memory scanning time revealed no significant differences between the three treatments, The visual analogue scale measuring "alert/drowsy" showed a significant increase in drowsiness one hour and three hours after treatment with alprazolam. This study lends support to previous studies regarding the psychomotor effects of the abovementioned drugs and indicates that spectral analysis of the EEG is a reliable parameter of drug induced central nervous system impairment. Department of Pharmacology, University of Pretoria, P. O. Box 2034, PRETORIA, 0001, South Africa.

S. HECQUET-DREYFUS*, M. BOURIN**, C.LAROUSSE** * Laboratoires UPJOHN Tour Franklin C6dex ii 92081 PARIS ** Laboratoire de Phsrmacologie CHU 44035 NANTES C@dex

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PHARMACODYNAMICS AND PHARMACOKINETICS OF REPEATED DOSES OF THE NEW ANXIOLYTIC DRUG ALPIDEM IN YOUNG AND ELDERLY HEALTHY VOLUNTEERS K.J. Zander*, B. Mangold**, H. TSberioh *~, G. Schmieder**, F. Eich*, G. Bianchetti***, P. Guillet***, P.L. Morselli***

A METHOD FOR C~ARACTERIZATION OF THE ONSET OF ACTION OF BENZODIAZEPINES AEMINISTERED BY INIRAV~NOUS INJECTION. S. L. Roqers, G. Rabin, R. Ltmjuoo and S. Reele. This paper describes the use of a psychometric test, the Digit symbol Substitution Test (DSST), as a method for measuring the onset of pharmacodynamic effect of benzodiazepines administered by rapid infusion. Two groups of 4 subjects were studied in separate, randomized, placebo-controlled trials. Group 1 received diazepam (D) at doses of 0.i0, 0.15 and 0.20 mg/kg vs. placebo (P). Group 2 received midazolam (M) at doses of 0.03, 0.05 and 0.07 mg/kg vs. P. Treatments were injected into an antecubital vein over 90 seconds. Simultaneously with dose administration, subjects began a 10-minute DSST. Observers recorded the number of substitutions (S) successfully completed during each 20-second epoch of test time (t), S vs. t was plotted and analyzed. Drug/Dose Performance Decay (_+S~M) mg/kg tonse t (sec) slope tma x (sec)

Alpidem, a new imidazopyridine compound, which binds predominantly to omega I receptors and which produces only mild sedation and no myorelaxation, has significant anxiolyric effects in anxiety syndromes; so far no withdrawal syndrome has emerged upon discontinuation of treatments of several weeks. Pharmacodynamics (choice reaction, critical flicker fusion, trail making, D 2 test, arithmetic task, digit span, KUSTA self-rating) and pharmacokinetics of alpidem and its metabolites SL80.0552, 83.0192 and 83.0725 were determined for a single dose (SD) administration of 50 mg alpidem (placebo-controlled cross-over) and for an open 7-day repeated dose (RD) administration of 2xSOmg alpidem in two parallel groups of 8 young (age 31.5 ~ 6) and 8 elderly (age 71.5 Z 4) male volunteers, who were studied in-house and simultaneously. The pharmakodynamic test revealed age effects on most tests, but no drug effects and no significant age x drug or age x drug x time interactions. Thus, alpidem had no impact on any performance tested in the young or in the elderly. For alpidem, Tma x was 1.9 • 0.3 h (SD) or 1.6 Z 0.3 h (RD) in the young and 2.3 • 0.4 (SD) or 2.0 ~ 0.3 h (RD) in the elderly (N.S.). TI/2 was 15.4 • 2h in the young and 24.0 • 3h in the elderly (p
D

0. i0 0.15 ....0.20

50~_i0 -0. 053+0. 010 135_+13 50~_ 6 -0. i06~_0. 016 155+_17 55~i0 -0.'11130. 017 165~ 5 M 0.03 80~_14 -0.053+0. 006 225_+15 0.05 65~_I0 -0. i19~_0. 026 175~_i0 0.07 65~ 5 -0.121~0. 029 200~14 Psychometric performance durir~ treatment with P did not decline from pretreatment levels. ~he rate (slope) of performance decay appears to be dose dependent for the low and middle doses of D and M; hcwever, this finding could not be extended to the high dose of either agent. In addition, data suggest that the tonse t and tma x of performance decline for M may be slightly later than that of D. These results indicate that the DSST can detect the rapid changes in psychc~etric performance which follow intravenous injection of D and M. studies using the DSST to characterize the initial l~mrmacodynamics of D and M are

ongoing. Hoffmann-LaRoche Inc., clinical Pharmaoology Unit 201 Lyons Avenue, NBIMC, D-II, Newark, NJ, USA 07112.

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CLONAZEPAM IN GILLES DE LA TOURETTE'S SYNDROME (MULTIPLE TIC DISORDER) F. S. Abuzzahab Sr., and H. Hopper. Although potent dopamine blocking medications , such as haloperidol (Haldol) and pimozide (Orap) have been promoted as the drugs of choice f o r control of t i c s in multiple t i c disorder, also known as Gilles de la Tourette's Syndrome, the fear of tardive dyskinesia from such long term neuroleptic treatment prompted us to explore the use of other agents. Fifteen patients (4 female and 11 male) with mean age of onset of t i c disorder at 8.17 years (range 5.5 - 14.5 years) received clonazepam (K1onopin) at a mean dose of 2.63 mg (range 0.5 - 8.0 mg). Mean age of patients was 25.6 years (range 10-58 years). Mean trough clonazepam blood levels obtained in the morning were 29.68 ng/ml (range 7.0 - 83.0 ng/ml). No therapeutic blood levels have been established f o r use of clonazepam in t i c disorder; the therapeutic range f o r use of clonazepam as an anticonvulsant is 20-60 ng/ml. Seven patients had blood levels less than therapeutic range, however, only one of those patients f a i l e d to achieve t i c control. Patients who f a i l e d to achieve t i c control had blood levels of 52, 42, and 14.3 ng/m1. There was no good c o r r e l a t i o n between blood levels and improvement (r = 0.22). The dose in mg/kg was s t a t i s t i c a l l y s i g n i f i c a n t l y correlated to the blood level at r = 0.52 at 95% confidence. Mean dose of clonazepam in mg/kg was 0.045 (range 0.006 - 0.148 mg/kg). F inally , by giving the t o t a ] dose at bedtime, there were minima] side .effects. In conclusion, clonazepam (K1onopin) proved e f f e c t i v e in c o n t r o l l i n g the t i c s of outpatients suffering from multiple t i c disorder, with minimum side e f f e c t s . (Supported in part by Psychopharmacology Fund and the PharmacoRsychiatry Fund of the Minnesota Medical Foundation) University of Minnesota, Box 393 Mayo, Minneapolis, Minnesota 55455 USA

OF LOFEPRAMINE IN COMPARISON TO ~ R O T I L I N E AND PLACEBO ON r FUNCTIONS IN HEALTHY VOLUNI'"hEFt: H. Hopes, G. Leopold, W. UngetWdm Objective: A research strategy based on information processing theory was applied together with conventional complex reaction tests to give evidence which stages of information processing are influencadby antidepressant drugs. Methods:Single oral doses of lofepramine (140 mg),maprotiline (100 mg), and placebo were administered in a randomized three-way cross-over design with I week wash-out between administration to 12 healthy male volunteers. Before, I and 3 hours after administration a battery of performance tests was administrated which included a p a r a digm (Posner, 1967) which measured separately reaction time for stimulus processing on a sensory-perceptional level and reaction time for abstract categorial evaluation. Furthermore a dual reaction task allowed to differentiatebetween recognition time and motor meve~ent time. Results: 140 mg lofepramine did not impair cognitive functions neither in conventional nor in information processing tasks. However it speeded up motor movement time. Maprotiline slowed down speed and ac~iracy in all conventional tasks and caused a decrease in speed of perception as well as speed of abstract categorial processes. Motor processes were not significantly influenced by maprotiline. Conclusions: There was good agreement between the results of conventional tests and tests based on information processing theory. However, the latter allowed mere differential interpretation of drug effect on cognitive functions.

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CLOBAZAM AND CLONAZEPAM IN HEALTHY VOLUNTEERS. J.D. Wildin. Barbara J Pleuvry and G.E. MaweF Clobazam and c]onazepam are used as adjunctive therapy in epilepsy. Clonazepam resembles other I-4 benzodiazepines in i t s spectrum o f a c t i v i t y (C.A. Cull, M.R. Trimble, R. Soc. Mad. Int. Cong. Symp. Series No 74, p.121-129, 1985). However, clobazam produces a comparative lack of sedation, which has been attributed to i t s I-5 structure ( I . Hindmarch, Br. J. Clin. Pharmacol [7] p.77S-82S, 1979). Previous studies have compared these dru9s with other benzodiazepines, buL there has never been a direct comparison of the two in man. We have therefore performed a placebo controlled double blind crossover comparison in healthy volunteers. Ten healthy volunteers ( s i x male; age 23-39 yr; mean body weight 66k9), received f i v e treatments in random order at seven day i n t e r v a l s . Each treatment was presented as i d e n t i c a l capsules containing clonazepam 0.5 or lmg, ctobazara 10 or 20mg, or placebo. No breakfast was allowed on the morning of the t r i a l . Alcohol and c affeine containing drinks were not allowed during the trial. Psychomotor and cognitive function tests were performed (e.9. Critical Flicker Fusion, Digit Symbol Substitution, Response Time) at pre-drug, hourly intervals to 8h, and at 24h post-dose. Venous blood was taken at e a c h tima to estimate d r u g plasma concentrations. Data was subjected to multivariate analysis of variance. Clonazepam, at both doses, produced si9nificant (pO.O5). These results confirm the working hypothesis that clobazam is less sedative than clonazepam provided the doses chosen are approximately equitherapeutic. Patients with epilepsy already demonstrate reduced psychomotor and co9nitive function, both as a consequence of t h e i r condition (D.B. Smith, B.R. Craft, J. Collins, R.H. Mattson, J.A. Crammer, Epilepsia [27] p.753-759, 1986) and of their anticonvulsant therapy. (M.R. Trimble, Epilepsia [28]($3) p.$37-$45~ 1987). Thus these findings have implications in the cholce of benzodiazepine as addon therapy in epilepsy. Therapeutic Drug Monitoring Group, Dept of Physiological Sciences, The University, Oxford Rd, Manchester U.K.

OBJECTIVE ASSESSMENT OF ANALGESIA INDUCED BY A SINGLE ORAL DOSE OF CLONIDINE H. P o r c h e t , P. P i l e t t a a n d P. D a y e r Experimental data and anecdotical clinical observations showed that intrathecal clonidine (C), an ~ 2 - a g o n i s t , i n d u c e s a s t r o n g and l o n g lasting analgesia. We investigated C induced a n a l g e s i a in r e s p o n s e to n o c i c e p t i v e stimuli a n d its l i n k s w i t h the o p i o i d p e p t i d e s system. METHODS: 7 healthy volunteers received (doubleblind, randomized, crossover and placebocontrolled) o r a l + i.v. p l a c e b o (P), o r a l C (200 ug) + i.v. P, and o r a l C + i.v. n a l o x o n e (N - 2.4 m g / 5 h). A n a l g e s i a w a s a s s e s s e d b y m e a s u r e m e n t of the s u b j e c t i v e (VAS) a n d o b j e c tive (RIII reflex) p a i n t h r e s h o l d s . P a i n w a s g e n e r a t e d b y t r a n s c u t a n e o u s s t i m u l a t i o n s of the s u r a l n e r v e (3 50 m A , at 500 ~ V for 500 ~sec). R I I I w a s r e c o r d e d b y s k i n e l e c t r o d e s o n the i p s i l a t e r a l b i c e p s f e m o r i s . R E S U L T S : A c l o s e c o r r e l a t i o n was o b s e r v e d b e t w e e n s u b j e c t i v e and o b j e c t i v e p a i n t h r e s h o l d s (r = 0.88, y = 1.2 9 x). P d i d not m o d i f y p a i n t h r e s h o l d s . C alone, and C + N i n d u c e d an inc r e a s e in t h r e s h o l d s : o b j e c t i v e t h r e s h o l d at 2h 21% [SEM 9] a n d 41% [i0] r e s p e c t i v e l y . O v e r a l l a n a l g e s i a l a s t e d for u p to 6h (p < 0.05 F r i e d m a n test). N c o a d m i n i s t r a t i o n tended to p o t e n t i a t e C a n a l g e s i a (NS). CONCLUSION: RIII is a r e l i a b l e a n d a c c u r a t e o b j e c t i v e i n d e x for p a i n t h r e s h o l d a s s e s s m e n t . A s i n g l e o r a l d o s e of C i n d u c e s a c l e a r a n d d u r a b l e a n a l g e s i a . T h i s e f f e c t is n o t a n t a g o n i z e d b y N, i n d i c a t i n g t h a t C a n a l g e s i a is n o t m e d i a t e d b y the o p i o i d p e p t i d e s system. T h e s e o b s e r v a t i o n s s u g g e s t that ~ 2 - a g o n i s t s c o u l d b e w o r t h w i l e d r u g s for p a i n t r e a t m e n t . Clinical Pharmacology, Geneva University H o s p i t a l , CH - 1211 G e n e v a 4, S w i t z e r l a n d

~'~"T

Department of Clinical Pharmacology, Laboratory for Experimental Psychopharmacology, E. Merck, Postfach 41 19 I)-6100 Darmstadt

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FLUMAZENIL DOES NOT PRECIPITATE WITHDRAWAL SYMPTOMSIN HEALTHY VOLUNTEERS PRETREATED WITH ORAL BENZODIAZEPINES A. W. Dunton, E. Schwam, J. Hendler and J. L. Siegel Flumazenil iF) antagonizes the central effects of benzodiazepines (BZs) by competitive interaction at the receptor site. Signs of precipitated withdrawal have been reported to occur in a v a r i e t y of animal species when a single dose of F was administered a f t e r pretreatment with a BZ. The severity is dependent upon the species, BZ used, dose, duration of pretreatment and the dose of F administered. The safety of F was assessed in healthy volunteers pretreated with oral BZs (85M/5F, mean age 29.8, mean weight 74.8 kg) at two study sites. Successive groups of 9 subjects received triazolam (TZ) (0.25 mg at bedtime) at site 1 and diazepam (DZ) (5 mg r i d ) at site 2 f o r O, 1, 3, 7 or 14 days. On the morning a f t e r the l a s t dose, IV midazolam (M; mean dose 10.8 mg) was administered to produce conscious sedation. Ten min l a t e r , 1 mg F in 10 ml (n=6/group) or 10 ml placebo (P; n=3/group) was administered in a double-blind manner (2 ml/min). There were no serious changes in v i t a l signs or ECGs in any subjects up to 36 hr a f t e r F or P, The number of 0 and 14 day subjects with adverse experiences ( a l l mild including dizziness, headache and i n j e c t i o n s i t e pain) is shown: 0 Days 14 Days Oral BZ F P F P DZ 076 073 176 073 TZ 0/6 0/3 i/6 0/3 Within 3 hr a f t e r F or P there was no difference (F vs P) in c l i n i c a l l y s i g n i f i c a n t v i t a l sign changes from before M f o r the 14 day groups compared to the 0 day groups. 97% and 23% of subjects exhibited a decrease in sedation a f t e r F or P respectively. Thus, F safely reversed M-induced sedation in subjects pretreated f o r up to two weeks with therapeutically used doses of BZs. Department of Clinical Research and Development and Clinical Pharmacology Unit Hoffmann-La Roche Inc., Nutley, NJ, USA

ADENOSINE AND NETHYLXANTHINES: POSSIBLE IMPORTANCE FOR NEUROLOGY AND PSYCHIATRY A. Erfurth,.M.G. Schmauss Recently the role of adenosine as a neuromodulator has been given increasing attention. Autoradiographic studies as well as studies with membrane fractions have explained the pharmacological properties of adenosine receptors. Both the AI- and A2- receptor have shown a discrete distribution in rat b r a i n (1,2). Nethylxanthines are known to antagonize adenosine at both receptor types. The sedative and anticonvulsive properties of adenosine have been shown to be a function of the At-receptor. The A2-receptor is specifically distributed in the rat brain being localized only in striatum, nucleus accumbens and olfactory tubercle (2), thus being distributed like the D2-dopamine receptor. SeVeral observations have led to the conclusion that the modulation of dopaminergic activity is an important function of the A2-adenosine receptor. It seems PoSSible , that a disturbed interaction between adenosine and dopamine is a causal factor of disorders of the basal ganglia and that this interaction is of some relevance for the clinical course and the treatment of endogenous psychoses.

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FLUMAZENIL PARTIALLY REVERSES MIDAZOLAM-INDUCED DECREASES IN INTRAOCULAR PRESSURE E. Schwam, J. Hendler and J. L. Siegel Flumazenil (F) is an imidazobenzodiazepine that antagonizes the central e f f e c t s of benzodiazepines by competitive i n t e r a c t i o n at the receptor s i t e . Midazolam (M) decreases i n t r a o c u l a r pressure (IOP) in healthy volunteers (R. Fragen, Arzneim.-Forsch. 31, 2273, 1981). To i n v e s t i g a t e whether F produces c l i n i c a l l y serious increases in IOP a f t e r M-induced decreases, a doubleb l i n d , p a r a l l e l group study was done using three groups of s i x healthy volunteers (9M/9F, mean age 33.5, mean weight 67.1 kg). On Day i a l l volunteers received IV placebo (P). On Day 2 one group received i mg F, oneI group 3 mg F and one group P. On Day 3 M (mean dose 9.7 mg) was given IV to a l l subjects to produce conscious sedation, followed 10 min l a t e r by F or P as on Day 2. lOP was measured each day before and several times a f t e r drug (within 10 min to 3 hr) by a hand held applanation tonometer. Sedation (Sed) was measured on Day 3 using a 5-point rating scale ranging from i (deep sleep) to 5 ( a l e r t ) . F or P alone had no e f f e c t on lOP. Data f o r Day 3 are shown below: Mean Sed Ratings and Left Eye/Right Eye lOPs (mm Hg) Group n Before M i0' After M s After F or P Sed lOP Sed lOP Sed lOP P 6 5.7 16.3/16.7 2.8 10.3/10.2 3.2 i0.0/~I.7 I rng F 6 5.0 16.7/17.3 3.2 12.5/12.5 4.8 14.5/14.8 3 mg F 6 5.0 17.3/18.2 2.3 11.2/12.5 4.7 15.3/14.5 M produced an increase in sedation in a l l subjects and a decrease in lOP in both eyes in 16 of the 18 subjects. F produced v i r t u a l l y complete reversal of sedation (p
QUANTITATIVE IMAGE ANALYSIS OF [NTRACEREBRAL GABA NEURON BY IHMUNOFLUORESCENTHISTOCHEMISTRY K. Sato I and T. Shibuya1'2 The alteration of GABA levels induce the several diseases leg., Alzheimer's, Huntington Chorea etc.). Thus, it is important to measure GABA levels in the central nervous system for evaluating the mechanism of neuronal diseases. In this study, a new immunofluorescent histochemical assay of central GABA neurons was performed using QABA antibodies for a quantitative imaging analysis, Immunofluorescent histochemistry: Whole brain was taken from male Wistar rats under urethane anesthesia after perfusienfixation with O, 1M phosphate buffer containing 4% paraformaldehyde. Brain was sliced in lO #m thickness in a cryostat to prepare a specimen for the indirect fluorescent antibody method Quantitative image analysis: For measuring the GABA level using a qualitative imaging analysis, the standard curve of GABA immunofluorescence was determined from the optical density and fluorescent intensity, The imaging analysis was done by making 256 colored indicators which were prepared from the illuminated films. In the nigra-striatal GABA neurons, the yellow-green colored cells and fibers which emitted FITCspecific fluorescence were observed. These emitting neurons are GABA positive neurons. The distribution and density of GABA immunofluorescence was quantitatively analyzed by the image analysis apparatus. These results indicate that central GABA neuron can be clearly identified and also quantified by our improved method. Further, this method may be applied to the identification of causes of several neuronal diseases. 1 ; Uept of Pharmacol, Tokyo Med Col, Tokyo 160 JAPAN 2 ; Dept of Biomed Sci, Univ of IL, Col of Ned at Rockford, IL 61101 USA

(I)

k. Erfurth, M. Reddin~ton. Neurosci. Lett., g~ (1986) 116-120 (2) M; Reddington, A. Erfurth, K.S. Lee. Brain Research 399 (1986) 232-239

Department of Psychiatry, University of Munich, Nu~baumstrasse 7, 8000 NGnchen 2 Federal Republic of Germany

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PP 15.29 REVERSIBLE UPREGULATIONOF ADENOSINEAI RECEPTORSFOLLOWING A SINGLE INJECTIQN OF CARBAMAZ~PINE(CBZ) /~NDCAFFEINE (CAF) C.H. Gleiter i , ~ , M.S..Clark L, C.J. Cain~, S.R.B. WeissL, P.J. Maranqos and R.M. Post z Recent studies have demonstrated that CBZ has adenosine AI receptor antagonist properties and chronic CBZ administration upregulates these receptors for at least 8 weeks*. I t is not yet clear i f this effect is reversible. Therefore the present study investigated the effect of a single injection of CBZ (50 mg/kg i . p . ) on adenosine A1 receptors using [3H]cyclohexyladenosine ([3H]CICA) and the peripheral type benzodiazepine receptor ([3H]Ro-5 4864) in rat cerebral cortex (CTX), hippocampus (HIP) and cerebellum (CER). Also the effect of a single injection of the adenosine antagonist CAF (150 mg/kg i.p.) was compared. Single point binding at the respective Kd concentrations was carried out in membrane preparations of the respective brain regions lh, 24h, 1 wk and 2 wk after the injection. Changes in number of binding sites (in % of controls): I hour 24 hours I week 2 weeks CBZ CAF CBZ CAF CBZ CAF CBZ CAF CTX [3H]CHA 0 0 0 0 +31# +I0 0 0 [3H]Ro-5 4864 0 0 +26* +8 0 0 HIP [3H]CHA 0 0 +21# +20# 0 0 [3H]Ro-5 4864 0 0 +29* +9 0 0 CER [3H]CHA 0 0 0 0 0 0 [3H]Ro-5 4864 0 0 0 0 0 0 (n = 9/group; * p < 0.01; # p < 0.005) Scatchard analysis of pooled tissue showed that the above changes were due to alterations in Bmax and not in Kd. Experiments with membranes from cortex at the I week time point using the GTP analog Gpp(NH)p showed that the upregulated adenosine AI receptors were functional. The number of peripheral type benzodiazepine receptors was only transiently upregulated. This study demonstrates that changes in adenosine AI receptor nLmIDer are reversible following a treatment with carbamazepine. 9Clin. Neuropharm. i0:443 - 448 (1987) INI/~AA, 2NIMH, Bethesda, MD 20892, USA, and 3Human Phanmcology Institute, Ciba-Geigy GmbH, D-7400 Tuebingen, FRG.

PP 15.31 VINPOCETINE - A NOVEL DRUG TO ALLEVIATE POSTHYPOXIC AND AGE-RELATED CHANGES IN TRANSMITTER RELEASE Ch. Wustmann, H.-D. Fischer, E. Rudolph, J. Schmidt, The K§ transmitter release from brain slices represent s a functional important quasiphysiological process with a high Ca+§ Ischaemia and hypoxia as well as aging impair Ca+§ transmitter release. In contrast to acute ischaemie/hypoxia, aging and posthypoxic conditions are characterized by a decline in K§ .dopamine release from striatum slices of rats. These changes may reflect deficits in neurotransmission with corresponding functional consequences in behaviour. Therefore, substances leading to an increase in synaptic efficiency are of interest in development of drugs for treatment of posthypoxic and age-related deficits. Long--term treatment of rats with vinpocetine (2xl0 mg/kg/d for 3-4 weeks), a novel cognition-enhancing and cerebroprotective drug, enhances significantly the Ca +§ dependent K+-stimulated dopamine release from striatum slices. The stimulus-release coupling is facilitated reaching a high level of transmitter release at much lower Ca++-level. Vinpocetine facilitates the recovery of posthypoxic dopamine release diminution and shows a significant retardation of the age-dependent lowering of dopamine release. We postulate that the bevahioural restoring effects of vinpocetine mainly in part are functionally connected with an enhancing effect on stimulus-effect coupling of transmitter release with corresponding consequences regarding the activity of affected transmitter system. Institute of Pharmacology and Toxicology, Medical Academy "Carl Gustav Carus", Lingnerplatz I, 8010 Dresden, GDR

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NIMODIPINE CHANGES THE RECEPTIVE FIELD (RF) PROPERTIES IN CAT VISUAL CORTEX AFTER INTRAVENOUS ADMINISTRATION

ANTIEMETIC EFFECT OF DIHYDROPYRIDINE CALCIUM ANTAGONISTS

HI.Koch "I, n.R.O.Di~e 2 cmdl'.B~P In controlled clinical trials it could be demonstrated that nimodipine prevents arterial vasospasm after subarachnoid hemorrhage (Allen S. et aL, New Eng.J.Med., 1983). In spite of the well investigated cerebrovascular effects, no obvious EEG-alterations (vigilance) aRcr administration of nimodipine in the cat have been observed (Hoffmeister et al., Proc.of the i st Int. Nimotop R Symposium, Munich 1984). We recorded single and multiple unit response with microeleetrodes in cat visual cortex. Light bars were swept at various speeds and orientations along trajectories in order to stimulate RFs. In addition, stationary stimuli (flashes) were applied. Recordings were performed before, 5 and 30 minutes after i.e. administration of 0.I mg,q~ nimodipine. On the basis of peri-stimulus-timehistograms (PSTH) the neural response was analyzed, including response amplitude, preferred orientation and direction, RF width and time-delay after moving stimulus as well as latencies following On-Off flashes. The latencies following On-Off stimuli showed only a slight tendency to prolongation. In contrast, the response strengh was generally reduced after 5 and increased after 30 minutes. The orientation selectivity was influenced by nimodipine and appeared to be decreased. The time-delay, whether defined as the onset o f response or the centre of PSTH-peak, was prolonged during the first control (5 rain.) and shortened during the second. On the contrary, the field width was first smaller and then larger. The direction selectivity was also altered by the application of the drug even though no systematic change was ascertained. In conclusion, our results suggest alterations of neuronal responses on the cellular level caused by calcium antagonists which could not simply be explained by cerebrovascular effects. In the discussion we address the question, whether the electrophysiological observations are due to alterations of brain activity (arousal) or to a specific neuratropic influence which might he related to psychotropie properties of the Ca-entry-blocker. 1Strahlentherapeutische Klinik der Univ., Steinhbvelstr.9, D-7900 Ulm; 2Univ.of California,UCSF,Coleman Lab,HSE 871,San Francisco, CA 94143; 31nst. f. Neuroinformatik der Ruhr-Univ., D-4630 Bochum

D . B. B e l e s l i n ~D. J o v a n o v i 6 - M i 6 i 6 ~R. S a m a r d ~ i 6 a n d S. M. Veljkovi6

A recent clinical report provide<] evidence daat the calcium antagonist~ nifedipine has significant anti-motion sickness effect (5.E.Marley and M.D.Joy~lqle Lancet II,1265~1987). However~ it is not yet known whether t/me calcium antagonists are also effective ininibitors of emesis induc6~:l by chemical stimuli. ~lerefore~ the aim of the present experiments was to study the antiemetic effect of calcium antagonists on nicotine- and clonidine-induce~l emesis in unanaesthetiz6
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BENZODIAZEPINES: POSSIBLE ANTICHOLINERGIC ACTION INDEPENDENT OF GABA I . R e k t o r I P. B r y ~ r e f C . S i l v a - B a r r a t I P. B a r t h u e l ~ C. M e n i n i The baboon Papio p a p i o d e v e l o p s a n o n - e p i l e p t i c myoc!onus s p o n t a n e o u s l y o r 20 min a f t e r i . m . b e n z o d i a z e p i n e (Bz) i n j e c t i o n (e.g. clonazepam 0 , 3 m g / k g ) . We found i n e x p e r i m e n t s i n 10 a d o l e s c e n t baboons t h a t a t r o p i n e ( 0 , 5 - 1 mg/kg i . v . ) p o t e n t i a t e d o r i n d u c e d t h i s myoclonus (Hy), that physostigmine (0,1 - 0,4 mg/kg & . v . ) c o m p l e t e l y a n t a g o n i z e d b o t h Bz-and a t r o p i n e - i n d u c e d Hy, t h a t p e r i p h e r a l l y acting mQNB and p r o s t i g m i n e had no a c t i o n , s u g g e s t i n g t h a t t h e B z - i n d u c e d My depends on a s t r o n g

PERIPHERAL INDUCTION OF BURST FIRING IN LOCUS COERULEUS IN BRAIN BY NICOTINE MEDIATED VIA EXCITATORY AMINO ACIDS C. S. Tung, L. Ugedo, J. Grenhoff, G. Engberg and T. H. Svensson The effect of systemic nicotine administration (50 ~g Kg -I i.v.) on the activity of brain ~oradrenaline neurons in the ]ocus coeruleus (LC) of chloral hydrate anaesthetlzed rats was analyzed, utiilz[ng single cell recording techniques and quantitative computer assessment of firing rate, degree of bursting and regularity of firing. Nicotine caused an increased firing rate Tn more than 90% of the Cells, with an average time of onset of 1.7 s. A marked increase in burst activity was observed as well as deregularization of the firing pattern. Intraventricularly administered kynurenate (I amol), an antagonist of excitatory amino acids (EAA), did not change the firing rate of the LC cells, but induced profound regularizat;on of their firing pattern into a pacemaker-like activity and completely abolished burst firing. Kynurenate also blocked all the above effects of nicotine on the LC neurons as well as their typical burst activation response to a peripheral, noxious stimulus such as paw pinch. Since the circulation time in the rat is about 20 s, these results provide unequivocal evidence for a peripheral site of origin for the rapid LC activation induced by systemic nicotine administration. The data also allow the conclusion that the nicotine-induced LC activation is indirect and dependent on EAA in brain. Our results provide evidence for a tonically active EAA input to the LC, being of critical importance for ~nduction of changes in the spontaneous, pacemaker activity of LC neurons into burst firing or more irregular firing patterns. It is suggested that the LC activation by nicotine may be quite significant for its clinical actions as well as for the initiation of tobacco dependence. Department of Pharmacology, Karolinska Instituter, Stockholm and University of Gothenburg, Gothenberg, Sweden

depression by Bz.

of

the c e n t r a l

cholinergic

system

The B z - i n d u c e d Hy was m e d i a t e d by Bz r e c e p t o r s as i t was b l o c k e d by s p e c i f i c r e c e p t o r a n t a g o n i s t RO 15-1788 which d i d n o t i n f l u e n c e a t r o p i n e - i n d u c e d My. However, t h e GA~'\ergic system i s p r o b a b l y not i n v o l v e d . P r o g a b i d e ( 4 0 - 8 0 mg/kg i . v . ) , b a c l o f e n (2 mg/kg i . v . ) and a l l y g l y c i n e d i d not i n f l u e n c e t h i s My. L o c a l i n j e c t i o n of G A B A in the p r e m o t o r c o r t e x , s u b s t a n t i a n i g r a , and ncl. g i g a n t o c e l l u l a r i s influence the photosensitive epilepsy while

b e i n g w i t h o u t any e f f e c t on n o n - e p i l e p t i c tl y . These f a c t s suggest t h a t b e n z o d & a z e p i n e s , by so f a r unknown mechanism, i n d u c e a d e p r e s s i o n of c e n t r a l c h o l i n e r g i c s y s t e m , i n d e p e n dent o f t h e i r GABAergic f a c i l i t a t i o n . CNRS, L a b o r a t o i r e de p h y s i o l o g i e n e r v e u s e , Gif-sur-Yvette, France Neurology Clinic, Purkynje University, Brno, Czechoslovakia

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S Y N ~ I S T I C ANTICONVUiSANT K'wp.~CTOF CARBAMAZEPINE AND

MORPHINE FORMATION FROMCODEINE IN RAT BRAIN: A POSSIBLE MECHANISM OF CODEINE ANALGESIA. F. Bochnerl,2, Z.R. Chenl, R.J. I r v i n e l , A.A. Somogyil,2.

VALPROATE IN EXP~IMENTAL MODELS OF EPILEPSY A. De Sarro, G. De Sarro, C. Ascioti

and F. Pisani

The possible synergistic effect against different types of experin~ntally induced seizures was investigated for various dose combinations of carbamazepine (CBZ) and so dium valproate (VPA). Animal seizure models tested ~ r e the following: (i) seizures induced in DBA/2 mice by two inverse benzo_ diazepine agonists,i.e, methyl-B-Carboline-3-carbo= xylate (B-CCM)

and methyl-6,7
carboline-3-carboxylate (E~3~) ; (ii) seizures induced by sound in DBA/2 mice ; (iii) seizures induced by pilocarpine in rats. The data collected

up to now suggest that CBZ and

together are superior to either one

alone

in t e ~

VPA of

spectrum of anticonvulsant activity. These results agree with sc~e observations made (Gupta and Jeavons,

in

epileptic

patients

J.Neurol.Neurosurg. Psychiatry 48,

1010,1985). Concerning neurotoxic effects,these will be

investiga=

ted in a further set of experiments including tests

(Rotorod test,etc. ).

The

standard

conclusive results of

these experiments will be illustrated and discussed the time of the "Conference". Istituto di Faz~acologia,Piazza XX Settembre 4, 98100 MESSINA. Italy.

at

The hepatic formation of morphine via O-demethylation from codeine is thought to be responsible for the analgesic effect of codeine. This hypothesis requires to be challenged as plasma morphine concentrations after codeine are low( <10 ng/ml), and morphine has difficulty in penetrating the blood brain barrier, fhe role of the brain in codeine metabolism is still not clear. The aim of this study was to investigate aspects of codeine metabolism in the brain in vitro and in rive. Rat brain homogenates were incubated with codeine (5-250 uM) in a NADPH generating system for 2-30 min (n=3). Morphine and codeine concentrations were measured in plasma and brain by HPLC. The maximum formation rate of morphine occurred at 10 min with a Km of 37.8~5.0 uH (mean~s.d.) and Vmax of 5.9~0.2 nmol/g brain. Incubation of rat brain mierovessel rich tissue (n=7) and brain homogenates (n=7) with codeine (160 uM) For 10 min resulted in morphine formation of 0.44e0.09 nmol/g and 0.24*0.08 nmoI/g respectively (p < 0.05). In rive, rats received an i.p. injection of codeine phosphate 20 mg/kg or morphine I mg/kg and were sacrificed at 30 min (n=4) and 60 min (n=4). At 50 min, brain morphine concentrations were 0.09~0.03 nmol/g after codeine and undeteetabte after morphine, whereas plasma morphine concentrations were 2.7• nM after codeine and 5.2-1.0 nM after morphine (p~0.05). At 60 min, brain morphine concentrations were 0.02• nM after morphine and 0.11• nM after codeine (p < 0.05). Brain and plasma codeine cooeentrations were 11.5~3.3 nmol/g and 5.8• nM respectively at 30 min. These results suggest that, after codeine administration, the formation of morphine in the brain rather than peripherally may mediate the anaIgesie effect of codeine. IDepartment of Clinical and Experimental Pharmacology, University of Adetaide and 2Department of Clinical Pharmacology, Royal Adelaide Hospital, Adetaide, 5000.

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PP 15.37

PP 15.39

EFFECT OF ETHANOL ON MEMORY CONSOLIDATION IN CDI MICE: ANTAGONISM BY THE IMIDAZOBENZODIAZEPINE RO 15-4513 C. CastellanQ Two sets of experiments were carried out with CDI mice tested In a one-trial inhibitory avoidance task. In a first group of experiments ethanol (i and 2 g/kg) was administered intraperitoneally (i.p.) immediately after training to mice fami]iarized, and non-familiarized, with the apparatus. The results showed that the effect of ethanol was less evident in experienced mice as compared with non-experienced subjects. In a second group of experiments the imidazobenzodiazeplne Ro 15-4513, which has been shown to have a high affinity for centra] benzodiazepine binding sites (M. Mohler eta;., Eur. J. Pharmacol. ~ , 191, 1984) was injected i.p., immediately after training, alone or in combination with ethanol. Ro 15-4513 alone (5 and I0, but not 2.5 mg/kg) improved memory consolidation of mice and its effect was time-dependent (no improvement was evident when it was injected 120 minutes after training); further, attenuation of the memory-impairing effect of ethanol was observed in mice pretreated with Ro 15-4513. From the first set of experiments it can be hypothesized that ethanol impairs memory consolidation in CDI mice through a decrease of emotiona]ity: a lower effect being evident in experienced animals, whose emotional level is lower in comparison with that of mice non-familiarized with the apparatus (see C. Casteilano et al., Behav. Brain Res. l! , 3, 1984). The results of the second group of experiments are consistent with other data suggesting a role for the GABA-benzodiazepine receptor-chloride ionophore complex in mediating the behavloura] effects of ethanol (see D.C. Rees and R.L. Balster, J. Pharmacol. Exp. Ther. _2_4_4, 592, 1987), and extend these observations to its influence on memory consolidation. IstJtuto di Psicobio]ogia e Psicofarmacologia de] CNR, vla Rend 1, 00198 Roma, Italy.

UNEXPECTED EFFECTS OF T A C R Z N E DERIVATIVE (9-amino-7-methoxy-l,2,3,4,tetrahydroacridine) U P O N T H E B M Y O C L O N U S IN T H E B A B O O N S P A P I O P A P I O ~ v e j d o v & M. r R e k t o r I.f, S i l v a - B a r r a t C.f, and M~nini

Ch,

T h e i n f l u e n c e of 7 - m e t h o x y t a o r i n e ( 7 - H E O T A ) on the n o n - e p i l e p t i c s t i m u l u s - s e n s i t i v e m y o c l o n u s of the P a p i o p a p i o b a b o o n w a s s t u d i e d in 5 a n i m a l s . T h i s t y p e of m y o c l o n u s is t h o u g h t depending on a cholinergic system disturbance,

s i n c e i t can be i n d u c e d by a t r o p i n e and b l o c k ed by p h y s o s t i g m i n e . 7-HEOTA i s b e l i e v e d as displaying a conspicuous anticholinesterase activity. S u r p r i s i n g l y , 7 - M E O T A (0,4 - 0 , 8 m g / k g i.v.) p o t e n t i a t e s the s t i m u l u s - s e n s i t i v e m y o c l o n u s o c c u r i n g s p o n t a n e o u s l y o r i n d u c e d by a t r o p i n e

(O,5 mg/kg i . v . ) . ously presenting

In t h e baboon n o t s p o n t a n e a stimulus-sensitive myo-

c l o n u s , 7 - H E O T A i n d u c e s the m y o c l o n u s , as a t r o p i n e d o e s . T h e m y o c l o n u s i n d u c e d by 7 - H E O T A is b l o c k e d by p h y s o s t i g m i n e (0,4 m g / k g

i.v.). These u n e x p e c t e d d a t a may r e s u l t from n o n - s p e c i f i c and d i f f e r e n t i a l actions of the drug i n d i f f e r e n t structures supposedly i n v o l v e d i n t h i s m y o c l o n u s . They i n d i c a t e t h a t t h e t a c r i n e d e r i v a t e s s h o u l d be t e s t e d on primates before their clinical use and a t t e n t i o n s h o u l d be p a i d t o t h e i r p o s s i b l y different e f f e c t s in d i f f e r e n t indications, N e u r o l o g y C l i n i c UJEP and KUNZ, Brno, Czechoslovakia L a b o r a t o i r e de P h y s i o l o g i e N e r v e u s e , Gif-sur-Yvette, France.

PP 15.38

PP 16.01

COMPARISON OF VOLTAGE-DEPENDENT 4Sea2+ UPTAKE BY SYNAPTOSOMES ISOLATED FROM BRAIN OF SPRAGUE-DAWLEY, WISTAR-KYOTO AND SPONTANEOUSLY HYPERTENSIVE RATS H. Honda1'2 t T. Shibu~a I'2 and B. Salafsky I K+-~stimulated 4BOa2+ uptake by synaptosomes was measured to study the strain differences between SPrague-Dawley (SD), Wistar-Kyoto (WI'Y) and spontaneously hypertensive rats (SHR). Method: Age-matched male SD, WKY and SHR (15-16 weeks old) were used. Synaptosomes (PZ fraction) were isolated from cerebral cortex homogenates. A suspension of synaptosomes was preincubated in the medium at 37~ After preineubation 4nOne+was added. After 15-2&0 sec loading with or without K + , uptake of 45Ca~§ by synaptosomes was arrested by Ca2+-free medium containing EGTA. Synaptosomes were then collected by filtration. Radio-activity was determined by liquid scintillation counting. Results and Discussion: 450a2+ uptake by synaptosomes isolated from cerebral cortex of SD, WKY and SHR was measured at 15, 30, 60, 120 and 240 sec time periods. The magnitude sequence of resting and depolarizationdependent 45Ca 2+ uptake were S}[R>WKY>SD. The fastest rates of resting and depolarization-dependent 4SCa 2+ uptake occured in each rat between 0 and 15 sec. Uptake rates dropped off quickly in both resting and depolarization. The sequence of rates of resting and depolarization-dependent 45Ca2+ uptake between 0 and ]5 see were SHR>WKY>SD. Our results that S}{R was fastest rate of 45Ca2+ uptake by brain synaptosomes in these rats may suggest the alteration of the rate of neurotransmitter release in human essential hypertension.

E R Y T H R O M Y C I N SHORTENS TRANSIT TIME IN H E A L T H Y VOLUNTEERS A. Gordin, J. Lehtola, P. Jauhonen, A. Kes~niemi and R. W i k b e r ~ E r y t h r o m y c i n s (E) often cause gastrointestinal side effects such as e p i g a s t r i c pain, nausea, v o m i t i n g and diarrhoea. These may be due to release of motilin, a direct m o t i l i n - l i k e effect or changes in intestinal bacterial flora. Gastrointestinal motility has been shown to be m a r k e d l y increased by E in animals. In order to e v a l u a t e the effect of two E derivatives on gastrointestinal motility we gave 12 h e a l t h y v o l u n t e e r s placebo, a s i n g l e R d o s e (i000 mg) of E stearate (ES) (Abboticin , Abbott) or a t h e r a p e u t i c a l l y e q u i v a l e n t single dose (800 mg) of E acistrate R tEA) (acetyl erythromycin stearate, Erasis , a new E derivative) in d o u b l e - b l i n d manner at 3 sessions 7 days apart. The oro-caecal transit time was m e a s u r e d by the hydrogen breath test u s i n g lactulose as the substrate. The transit time was e s t i m a t e d from the Hp-peak (ppm) in e n d - e x p i r a t o r y b r e a t h by two methods (Tl:representing the "front" and T ~ : r e p r e s e n t z n g the "bulk" of l a c t u l o s e reaching t~e colon). T I (mean + SD) was 50 + 28 in p l a c e b o group, 38 ~ i~ in EA a n d 31 + 18 mYn in ES group (p < 0.01 c o m p a r e d with p l a c e b o in both groups) and T9 74 + 27, 64 + 17, and 46 + 23, resp. w i t h the l ~ t t e r - m e t h o d also the d i f f e r e n c e b e t w e e n EA and ES was s t a t i s t i c a l l y s i g n i f i c a n t (p < 0.05). The subjects recorded symptoms a t t r i b u t a b l e to ES but not to E A . In conclusion, ES and EA shorten the o r o - c a e c a l transit time ( g a s t r o i n t e s t i n a l motility) in man. The EA affects the transit time less than ES in the doses used. R e s e a r c h Centre, O r i o n P h a r m a c e u t i c a , Espoo and D e p a r t m e n t of Internal Medicine, O u l u University Central Hospital, Oulu, Finland

I:

2:

Department of Biomedical Sciences, University of Illinois, College of Medicine at Rockford, IL 61107-1897, U.S.A. Department of Pharmacology, Tokyo Medical College, Tokyo 160, Japan

A 330

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PP 16.04

EFFECT OF FOOD ON ABSORPTION OF 2'-ACETYLERYTHROMYCIN STEARATE A. J ~ r v i n e n , S. N y k ~ n e n a n d Q. M a t t i l a Concomitant food i n t a k e a f f e c t s 0nly w e a k l y the a b s o r p t i o n of e r y t h r o m y c i n (E) b a s e w h i l e t h a t of E e s t o l a t e is r e d u c e d a n d the a b s o r p t i o n of E ethylsuccinate m a y e v e n he e n h a n c e d ( W e l l i n g & Tse, J. A n t i m i c r o b i a l Chemotherapy 9, 7, 1982). 2'-acetylerythromycin s t e a r a t e (2EA) has b e e n s h o w n to be well a b s o r b a b l e in the f a s t i n g s t a t e ( T u o m i n e n et al., J. A n t i m i c r o b i a l Chemotherapy 21 Suppl. D, 45, 1988). The e f f e c t of s t a n d a r d i z e d l i g h t or h e a v y b r e a k fast on the a b s o r p t i o n f r o m 2EA 400 mg t a b l e t s b.i.d, was s t u d i e d on 14 h e a l t h y v o l u n t e e r s . Abs o r p t i o n of 2EA w h e n t a k e n i m m e d i a t e l y b e f o r e food was c o m p a r e d to t h a t of f a s t i n g s t a t e a f t e r a s i n g l e d o s e and at s t e a d y state. P l a s m a l e v e l s of E, 2EA and t h e i r a n h y d r o f o r m s were' d e t e r m i n e d ~ i t h HPLC. No s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s w e r e obs e r v e d in the p h a r m a c o k i n e t i c parameters. Absorpt i o n was s l i g h t l y d e l a y e d by food a f t e r a s i n g l e d o s e but this was not o b s e r v e d at s t e a d y state. The r e l a t i v e b i o a v a i l a b i l i t i e s of f a s t i n g c o n d i tion at s t e a d y s t a t e as c o m p a r e d to l i g h t b r e a k fast w e r e 1 . 0 ~ 0 . 4 (mean~sem) for E and 0 . 9 + 0 . 2 for 2EA and that as c o m p a r e d to h e a v y b r e a k f a s t 1 . 6 ! 0 . 4 for E and 0 . 9 ~ 0 . 2 for 2EA. The p e a k p l a s m a l e v e l s of E r a n g e d 0 . 7 5 - 0 . 7 8 ug/m] and t h o s e of 2EA 3 . 3 - 4 . 5 ug/ml at s t e a d y state. In 2 s u b j e c t s a f t e r a light b r e a k f a s t and in 5 a f t e r a heavy breakfast detectable concentrations of E or 2EA w e r e o b s e r v e d o n l y at s t e a d y state. It is c o n c l u d e d t h a t food does not s i g n i f i c a n t l y a f f e c t the a b s o r p t i o n ef 2EA. D e p a r t m e n t of P h a r m a c o l o g y and T o x i c o l o g y , Univ. of H e l s i n k i and M e d i c a l D e p a r t m e n t , Orion Pharmaceutica, P . O . B o x 65, S F - 0 2 1 0 1 E s p o o , Finland.

SKIN AAD SKIN STRLCTL~ IkFECTIONSTREATEDWITHCL~RIIICRO4YCIN

PP 16.03 T~ TRs

OF ST~PTOCI]CCALPHARYNGITISWITHELARITkf~]MYCIN

M. Vandenaurg,M. Lu~pkin, T. Sebree, J. Cook, L. Wight, R. Bachand In 3 clinical studies involving 596 patients, the efficacy of a new macrelide antibiotic, elsrithromycin (C) 250 mg b.i.d, in patients with proven Gro40 A beta ha~rolytie etrapteaascal (GABHS) pharyngitis was compared with that of penicillin VK (P), 250 mg t.i.d. (study I) or q.i.d. (study 2) or erythrcmycin (E) 500 mg b.i.d. (study 3). Clarithrcmyein was originally identified by Talsho PharmacaJticals and is under Warldwide development by Abbott. All treatmemts were given for 10 days. Clinical success rates were 999,~(C), 99Z (P) aid 95Z (E). Bacteriological success rates (evaluabie patients in G~HS was eradicated at p~t-treatment ~d fallow~p visits) were 95Z, 9~& and 9~ respactively. In vitro susceptibility of GABHSto the 3 drugs Was compar~bte (9~,4 9 ~ and 9~ respectively). Adverse events profiles were comparable without any significant differences. We conclude that (C) is a useful agent for the treatment of G ~ pharyngitis. Medical and Clinical Research Consultants Lint[ted,Lewis House, I Milc~ay Road, Romford, Essex R47 ?DA.

T. Sebree, M. LuT~
J. Cod<, R. Bach~

Clarithrcmycin (C) is a new macrelide antibiotic originally identified by Talsho Pharmaceuticals and clinically developed by Abbott Labs. In 4 clinical studies the efficacy and safety of 250 mg b.i.d, in the treatment of skin ~rd skin structure infections (SSTI) were evaluated in comparison to eryth~:mycin (E) 250 mg q.i.d., jesamyein (J) 500 ng t.i.d. and cefadraxil (CX) 500 mg b.i.d. 145 patients were treated with (C) and 146 with con~ator agents. Clirdcal ~access rates were 9 ~ (C), 9 ~ (E), 9 ~ (J) and 9 ~ (CX). Banterialegiealsuccess rates (bastsriologieally evaluable patients in whan the susceptible pathogen was eradicated past-treatment) Were 95,% 9~,~,9 ~ and 80Z respectively. The 3 comonly isolated p a t h ~ in SSTI Were all susceptible to (C): (0

(E)

(j)

Strap. pyogenes IOC~ (39/39) IOE~ (25/25) IOE~ (13/13)

(CX) -

S.asreus

9 ~ (144/156) 9E~ (85/9~) I0~ (~2/&2) IQ]~,~(11/11)

S.epidermidis

84% (38/45)

7 ~ (24/33) IOE~ (9/9) IOC~ (5/5)

Few clinical adverse events were reported, mostly affecting the gastrointestinal system and mated as mild to moderate in nature. There were no clarithrcmyein related serious adverse events in any of these studies. We conclude that elarithr~cin is an effective,well tsIerated treatment for SSTI with the advantage of a twice daily dosage reg~Ten ~hich should aid out-patient compliance. Abbott Laboratories, Chicago, Illinois, USA.

PP 16.05 CLARITPEOMYCININ T~ TREAI~T OF BRONCHITIS R. Bach~, L. Wight, J. Cook, M. VardenBurg, M. Lu~kin, T. 5ebree The efficacy of clarithre~in (C), a new synthetic n~crolide, originally identified by Taisho P h a r ~ i c a l s and under worldwide development by Abbott, in the treatment of bronchitis was evaluated in I open a-d 6 comparative studies. A total of &37 patients received (C) with an additional 113, 31 and 137 patients received aTpicillin (A), erythromycin (E) and jesamymin (J) respectively. Efficacy vcesassessed by eaMoaring pre- and post-therapy clinical signs and symptoms assessed by the investigator, and the investigatorS' classification of the patient's clinical response post-treatment. Bacteriologicalresponse was assessed by appropriate pre- and Past-treatment culture and sensitivity testing. (C) was well tolerated as evidenced by a low incidence of adverse events reported. In all studies, there Were impressive clinically and statistically significant improvements in essentially all synptoT6 assessed such as cough, sputL~, pyrexia and the presence or absence of rates and rhenchi. There Were no clinically or statistically significant differences between (C) and the comparative agents. 372 of the 437 patients who received (C) ware clinically evaluable, 337 (91,~ of whon were clir~cal successes (cured or inpreved), as judged by the investigator, pest-treatment. Clinical success rates for the three conp~rative arfcibioticswere ~9/93 (gL~) (A), 21/27 (7~) (E) and 93/103

( ~ ) (o).

Complete eradication of the pathogen Was decum~ntedin 185/209 (8~) (C) patients, 24/27 (8~) (A) patients, 10/10 (10076) (E) patients and 57/62 (9~) (J) patients post-treatment. These r ~ t s sh~ that (C) is at least as effactive as three major antibiotics currently used in the treatment of bronchitis. Importantly, (C) achieved its success rate with a b.d. dosing r e c ~ conpared to a q.i.d, reg~Ten for (A) and erythron~yeinand a t.i.d, reginmn for (S) used in tt~es studies. ]he sinplified dosing schedule should aid out-patiest compliance. Abbott Laboratories, Chicago, Illinois, USA

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PP 16.06

PP 16.08

MICROSIQL~IC~_ PROFILE OF CL~RIIhRONYCIN

Prepared by Dr. R. Jalali Mazloman

M. L u ~ i n , L. W i l t , J. Cook, M. Va~enB~, T. Sebree, R. Bach~ Clarithremyein (C)is a new syr#_~eticmacrolide antibiotic originally

Dr.

identified by T~sho Pharmaceuticals and Oeder worldwide development by ~obott. In vitro, its entimierobial spectrum is similar to that of other macrolides, but with MIC's I or 2 log2 dilutions more potent than eryt~in against all organisms except H.influenzes. F ~ v e r , a 144]H met=Noolite is produced in man which is more active against H.inflLenzae than the parent; in therapeutically relevant ratios, the metabolite and parent coapoand together yield an MIC that is I-2 log7 dilution more potent than erythrcmyein against H.inflLer~ae. In an-extensive clinical study programe, isolates frcm patients with a variety of iedicaticrs were tested for susceptibility to (C) or the control agent used; either 8mpicillin (A)~ erythremyein (E)~ josamycin (J)~ penicillin (P)~ 8mo• (AX) or esfedroxil (Or). Percentage (~6)sueneptibilities are

tabulated below: H.influenzso

C A E J P AX LT (n) ,% (n) ,% (n) % (n) % (n) ,% (n),% (n) 9~ 172 92 21 95 8 88 87 68 16 81 -

Hassan Baradaran

Title:

1 0 th Jan 1989 In Vitro evaluation of the efficacy of Amikacin & .................................................

In order of verification of Amikacin( A Kind of aminoglycosides which has recently entered to the medical field of Iran) on pseudomonas Aerogenosa and also its compars ion with other Aminoglycosides

from the Iranian patient who have referred to the Medical centers of Mashhad Ferdowsi University In this research,

B.catarrhalis

52 96 15 38

2 100 20 95

6

0

have been studied as In -

vitro from the isolated samples of bacteria which removed

.

at first, pseudomonas Aerogenosa diso-

lated from the various kinds and other testing of Bio -

5.aureus

234 93 17 55 96 91 72 100

-

9 56 11 100 chemical methods and comparsion of this bacteria with

5.pnouTonia

252 97 26 96

9100136

94

25100

Kirby - Bayer method and the sensivitity test was carried

H.parainflosnzae

12 100

S.pyogenes

64 100

S.epidermidis

45 84

G/~HS

4 100

out and the effects of amikacin and said bacteria were 25 100 51 180

-

245 99

55 75

9 100

119 100

-

studics and finally the obtained results were c o m p a r e d

8 100

-

-

5 100

with the effeets of the aminoglycosides which there were in Iran e.g. Gentamycine

117 99

& Kanamicine.

( n ) = total organisms tested.

(C) demonstrated i~oreesive in vitro activity against all organisms tested. (C) had the most consistently high susceptibility rates against all the pathogens tested. Comparative susceptibility of H.influenzae to (C) was exosllent even in vitro witheut the in vivo benefit of the estive metabolite. (C) will be a useful oral antibiotic against the cunmsoly isolated pathogens in com~urnty-so~red indications. ~hbott Laboratories, Chicago, Illinois, USA

PP 16.07

PP 16.09

THE SAFETY AND TOLERANCE OF THREE IV AND TWO IM MULTIDOSE REGIMENS OF ISEPAMICIN. G.F. Perentesis,* M.B. Affrime, M. Micoud, N.J. Carson, C. Korduba, P.J. Lawton, and C. Lin, Schering Corporation Kenilworth, NJ. Isepamicin, a new broad spectrum amiooglycoside antibiotic has been studied in m a n after IV and IM administrations. Three groups of nine volunteers (6 active and 3 placebo) each received isepamicin or placebo by 30 min IV infusions. Group I received 7.5 mg/kg qd x i0 days, Group II received 7.5 mg/kg bid x 10 days, and Group III received 15 mg/kg x I0 days. In a second study two groups of nine volunteers (6 active and 3 placebo) received Isepamicin or placebo by IM administration. Group I received 7.5 mg/kg qd x i0 days. Group II received 7.5 mg/kg bid x I0 days. Aside from routine safety parameters, auddometric tests (standard audiograms 500-8,000 HZ and high frequency audiograms 2,000-18,000 HZ), creatinine clearance, B2 microglobulin, and serum creatinine were evaluated. In addition, peak (C max) and trough (C min) plasma concentrations were determined on days 1,7, and 10 for all treatments. The results of the study demonstrated no clinically significant changes in audiometric evaluations at any frequency and there were no clinically significant changes in renal function for either the IV or IM groups. All treatments were safe and well tolerated

PHARMACOKINETIC5OF AMIKACIN IN PATIENTS WITH SEVERENEUTROPENtA. M. Andrejak, L. Hary. Pharmacokinetics of amikacin was studied in 7 patients (group N.P.) w;th severe neutropema (neutrophil count < 500 ram-3) induced by chemotherapy in cancer, comparatively to 6 healthy subjects (group H.S.). During the first 6 hours after 7.5 mg.kg-1 i.v. injection during 30 minutes, serum amikacin levels (determined by enzyme immunoassay) showed a biexponential decrease in the two groups. The values in N.P. group were lower than in H.S. group, especially for the Cma~(226 f 2.1 mg.1-1 vs 34.2 +- 3.2 ; p < 0.01 ). Small and non slgnificant changes were found in N.P. group for elimination half life (-16%), total clearance (+15%) and apparent volume of distribution (Vd area + !5%). The volume of central compartment appeared greater in N.P group : 0.28 + 0.04 l.kg-I vs 0.14 f 0.03 in H.S. (p < 0.02) (respectively 64 % and 37 % of Vd area). The initial distribution of amikacin in a larger central volume may explain low Cma• levels in N.P. group as these we had previously observed' in such patients. The values of peak levels might be then therapeutically less efficient, especially in the case of general severe infections (i.e septicemia) particularly if perfusion rate is smaller than that we used in the present study. But, if amikacin dosage is increased in N.P. to achieve sufficient peak level, the risk of toxicity might be reconsidered. Un;te de pharmacologic clinique, CHRUd'Amiens, H6pitat Sud, B.P 3009, 80030 AMIENS, France.

dose (mg/kg) 7.5 qd 7.5 bid 15.0 qd

Cmax (mcg/ml) IV IM 52.0 21.3 49.5 27.8 93.5

Cmin (mcg/ml) IV IM 0.4 83 1.0 97 0.5

In conclusion, no changes were observed in nephrologic audiologic parameters monitored over i0 days of both IV or IM drug administrations at all dose levels.

or

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KINETICS OF CEFTRIAXONE IN ASCITIC FLUID AND PLASMAAFTER INTRAVENOUS ADMINISTRATION MA Artaza, E Cusid6, J G6mez*, E Ribera*, V Moreno, JM Arnau The aim of this work was to study the levels of ceftriaxone (CF) in infected a s c i t i c f l u i d (AF) and compare them with those reached in plasma. Fourteen hospitalized patients were included in the study, with a c l i n i c a l diagnosis of cirrhosis and spontaneous p e r i t o n i t i s . The c r i t e r i a f o r inclusion were the c l i n i c a l data compatible with the diagnosis and the presence of more than 500 neutrophils per mm3 of AF. The isolated organisms were: E__. z coli (6), Klebsiella (2), Enterobacter (1), Str. ~pneumoniae ( i ) and 4 negative cultures. The ceftriaxone dose was 2 g every 24 h, as a 20 m i n i . v. infusion. The blood and AF samples were drawn at steady state I and 24 hours a f t e r the infusion had started, in 4 patients samples were also drawn at 5 and 11 h. The CF concentrations were determined by HPLC. The ceftriaxone levels were as follows: lh 24h plasma (R• 201• 56• (range) 110-371 8-163 AF (R~S.D.) 64• 29• (range) 31-175 4-86 In the 4 patients in whom 4 samples were drawn, CF plasma h a l f - l i f e was 10 h, 9.5 h, 8 h and 22 h; the l a t t e r had a kidney f a i l u r e with a creatinine clearance of 3.6 mg/dL. Minimal Inhibitory Concentrations (MIC) were always under 16 pg/ml, and in 5 cases <8 pg/ml. In 5 patients AF levels were below 16 ~g/ml a f t e r 24 h. Three patients died from the infection. We concluded that CF achieved AF levels lower than those achieved in plasma, but that the drop in AF is slower than in plasma,, which allows to keep a suitable level/ME relation in the long run. Servei de Farmacologia Clfnica. *Servei de Medicina Interna - Patologia Infecciosa. CS Vall d'Hebron. 08035 Barcelona.

CEFPIROME (HR810) DOSE LINEARITY AND MULTIPLE INTRAMUSCULAR DOSE KINETICS B.H. Meyer , F.O. Muller , H.G. Luus , N. de la Ray , H.J. RSthig , M. Badian and H.G. Eckert The results of 2 studies are reported: i. Doses of 0.5, 1 and 2g cefpirome (HR810), a new broad spectrum cephalosporin derivative, were given i.m. to 18 heaithy men (wash out period of 7 days) to study dose linearity. 2. Pharmacokinetic parameters were determined in I0 healthy men after a single i.m. dose of ig HR810 and after the last of 7 doses, the first six doses having been given twice daily for 3 days. The results were: (mean values) Study Dose linearity Single vs Multiple Dose 0.Sg ig 2g ig ig Cmax (ug/ml) 12.2 23.2 43.0 20.5 25.3 Tmax (h) 1.6 1.9 2.3 2.1 1.5 Terminal half life 2.0 2.0 2.1 2.3 2.0 AUD (ug/ml.h) E6 115 228 AUD(12h) (ug/m].h) 107 AUDss(12h) (ug/ml.h) ii0 AUDC (ug/ml.h) 57 116 230 112 Cs (ml/min) 151 148 148 150 154 MT-vsys (h) 4.0 4.2 4.6 4.6 3.7 V - s y s / f (~) 37 38 41 42 35 Urinary recovery (mg) 346 753 1547 776 821 Renal clearance (ml/min) i05 iii 114 116 126 Cmax = peak concentrations; Tmax = time to peak; AUD = area under the data pairs; AUD(12h) = AUD up to 12 hours; AUDss(12h) = AUD at steady state for 12 hour intervals; AUDC = AUD extrapolated to infinity; C~-tot/f = relative total clearance; MT-vsys total mean time; V-sys/f = relative total volume of distribution. No accumulation occurred in the multiple dose study. Conclusion: An excellent linear relationship was shown between HRSI0 dose and Cmax, AUD and urinary excretion. No relevant differences were present between pharmaeokineties pertaining to single vs. multiple dose phases. Dept. of Pharmacology, University of the Orange Free State, P.O. Box 339, Bloemfontein, 9300, South-Africa

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PP 16.13

TISS~

C?~E~TIO~

O~ CEFOTI~ ~N

. ~

c0Lg~

M.Schulz ' ,A.Schmoldt ,J.BrennerJ,T.Mansfeld ~ It is g e n e r a l l y a c c e p t e d t h a t s u r g e r y of t h e c o l o n s h o u l d be d o n e u n d e r a n t i b i o t i c p r o p h y l a x i s of p o s t o p e r a t i v e i n f e c t i o n s . T o o u r k n o w l e d g e , cefotiam concentrations have not been determined in c o l o n t i s s u e . We t h e r e f o r e i n v e s t i g a t e d t h e p e n e t r a t i o n of cefotiam into plasma and colon tissue during the w h o l e s u r g e r y f o l l o w i n g e i t h e r a d m i n i s t r a t i o n of a 2 g i.v. d o s e just b e f o r e s t a r t i n g a n e s t h e s i a or w i t h an a d d i t i o n a l 2 g d o s e t w o h o u r s e a r l i e r in 24 p a t i e n t s w i t h c o l o n c a r c i n o m a undergoing surgery. Tissue specimen of the colon w e r e t a k e n d u r i n g o p e n i n g the c o l o n a n d a f t e r closing the anastomosis. Blood samples were drawn simultaneously. Cefotiam tissue and plasma c o n c e n t r a t i o n s w e r e d e k e r m i n e d by a n e w H P L C m e t h o d ( r e c o v e r y >80 % for c o l o n t i s s u e ) . The results showed that sufficient colon t i s s u e l e v e l s w e r e o b t a i n e d d u r i n g the o p e r a t i o n . At the t i m e of a n a s t o m o s i s c l o s u r e the v a l u e s ranged between 7.4-94.0 ~g/g (1.83-0.83 h after Ix2 g) a n d 9 . 1 - 7 2 . 3 ~ g / g (2.4-0.91 h a f t e r b e g i n n i n g of a n e s t h e s i a a n d 2x2 g). C o r r e s p o n d i n g p l a s m a c o n c e n t r a t i o n s w e r e a b o u t 3.0 a n d 2.4 t i m e s h i g h e r a f t e r Ix2 g a n d 2x2 g c e f o t i a m , respectively. It is t h e r e f o r e c o n c l u d e d t h a t c e f o t i a m p l a s m a a n d t i s s u e l e v e l s a f t e r a s i n g l e 2 g i.v. d o s e are a t t a i n e d w h i c h m i g h t be s u f f i c i e n t for an antibiotic prophylaxis during colon surgery. IInst. o f L e g a l M e d i c i n e (2now: ABDA, F r a n k f u r t ) , 3 H o s p i t a l R e i n b e k , U n i v e r s i t y of H a m b u r g , F R G

PHARMACOKINETICS AND TOLERANCE OF CEFPIROME AFTER SINGLE & MULTIPLE INTRAVENOUS ADMINISTRATION IN ELDERLY VOLUNTEERS H . - J . Roethig, B.H. Meyer and H.G. Luus Cefpirome (HR 810) i s a new cephalosporin a n t i b i o t i c f o r p a r e n t e r a l use w i t h a broad spectrum o f a c t i v i t y also against b a c t e r i a l s t r a i n s t h a t ere f r e q u e n t l y r e s i s t a n t t o t h i r d generation cephalosporins. The aim o f t h i s study was t o assess t h e pharmacokinetics end t o l e r a b i l i t y of 2g cefpirome a f t e r a s i n g l e dose and m u l t i p l e doses (11 doses, 2g b . i . d . ) i n e l d e r l y Volunteers. Eleven v o l u n t e e r s were r e c r u i t e d f o r the study, mean age 73 years, range 68-79 years, mean weight 70 kg, range 56 85 kg. There were 5 males and 6 females. One o f t h e female v o l u n t e e r s dropped out due t o mild d i a r r h o e a . Serum and u r i n e samples were c o l l e c t e d up t o 24 and 96 hours respect i v e l y a f t e r s i n g l e dose and t h e l a s t dose o f t h e m u l t i p l e dose phase. Cefpirome was determined by HPLC. Results: Pharmacukinetics in serum: Parameter single dose phase multiple dose phase ti/2. b (h) 3.43 (0.39) 3.13 (0.60 AUC I12h) (ug/ml.h) 451 (122) AUDC(ug/mi.h) 466 (123} CL-tot (ml/min) 75.8 (18.6) 78.9 (21.5) V-ss (1) 21.6 (3.54) 20.9 (4.86) Pharmacokinetics in urine: Parameter 9ingle dose phase(O-g6h) multiple dose phase(O-12h) Ae (mg) 1414 (225) 1566 (]35) Total recovery of dose 70:7 (11.3) 78.3 (6.74) Cl-ren (ml/min) 53.2 (15.4) 61.3 (]5.9) Cl-creat (ml/min)* 55.3 (17.0) 78.9 (16.0) * for 24h periods following single and last multiple dose Discussion: Cefpirome was w e l l t o l e r a t e d by a l l e l d e r l y v o l u n t e e r s . The mean t e r m i n a l h a l f - l i f e in e l d e r l y was 1 - 1 . 5 hours longer than i n young v o l u n t e e r s . This c o r r e sponds w i t h t h e decreased r e n a l drug clearance due t o a reduced o r e a t i n i n e clearance. A l l o t h e r pharmacokinetic parameters were comparable t o those found in h e a l t h y young v o l u n t e e r s . M u l t i p l e i n t r a v e n o u s a d m i n i s t r a t i o n of cefpirome showed s i m i l a r k i n e t i c s as compared t o s i n g l e intravenous administration. Department o f C l i n i c a l Pharmacology, C l i n i c a l Research, Heechst AG, P.O. Box 800320, 6230 F r a n k f u r t (M) 80, FRG

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T H E E F F E C T I V E N E S S OF N O R F L O X A C I N IN U R I N A R Y TRACT INFECTIONS Z. Pieloch, H. Adamska-Dyniewska, W. Tkaozewski, I. Lewi~ska, M . B r z e z i ~ s k i

THE I N F L ~ OF ERINARY PH ON THE PHARMACOKINETICS AND CRYSTALLURIA OF OFLOXACIN IN HEALTHY V O L ~ . A.W. Pidgen ~, A.G. Whitworth ~=, H.G. Eckert A, and J.D. Collins Dept. of Clinical Pharmacology, Hoechst UK Ltd, Milton Keynes, England ~. Pharma Research, Hoechst AG, Frankfurt a.m.F.R.G. A Ofloxacin (TarividR) is a new broad s p e c ~ ant~ntcrobial agent wb/ch possesses high antibacterial activity against

The studies were aimed at an e v a l u a t i o n of the efficiency of norfloxacin in vitro and in vivo. The group consisted of 50 p a t i e n t s w i t h chronic

unirary tract

infections a n d s i g n i f i c a n t baoteriuria, treated with a m p i c i l i n o r other chem i o t h e r a p e u t i c s without effect. The m e a n age: 58+14 yr, body weight: 71+18 kg. Escherichia coli resistant to a m p i c i l l l n was the most frequent bacteria in urine /34%/. Klebsiella was present i n 18%, Pseudomonas in 6%, Enterohacter in 2%. The sensitivity of bacteria cultured in urine t o norfloxacin was investigated

before treatment. The sensitivity was observed in 8 6 % of cases /excellent in 36 and good in 50%/. N o r f l o x a c i n was a d m i n i s t r a t e d 400 m g twice daily d u r i n g 5-7 days. A v e r y good clinics1 effectiveness of n o r f l o x a c i n i.a. withdrawal of pain, r e d u c t i o n o f leucocyturia and bacteriuria - were obserwed in 50% of patients, a g o o d effect in 36~. C r e a t i n i n e in serum before and a f t e r treatment v a r i e d insignificantly: 1,18+0,29 and I ,12+0,28 mg/dl. Two patients complalned of epigastric discomfort w i t h o u t need of d i s c o n t i n u a t i o n of treatment. N o r f l o x a c i n is v e r y effective chemiotherapeutic drug in the urinary tract infections. Zsk~ad P a r m a k o l o g i i KliniczneJ IMW W A M 90~451 ~,6d~, ul. K n i a s i e w i c z a 1/5, Poland

both gram-positive and gram-negative bacteria including Pseudomonas aeruginosa. Single oral doses of 200rag ofloxacin were administered to ten healthy volunteers (5 male, 5 female) under normal, acidic and alkaline urinary pH conditions (average pH = 6.72, 5.33 and 7.91 respectively). Pla~ma and urine samples were collected up to 48 hours for pharmacokinetic purposes and urine sanples were collected up to 8 hours after dosing for microscopic examination. The pbarmacokinetlcs of ofloxacin were not significantly altered under alkaline pH conditions. However, administration of ofloxacln under acid pH conditions caused a small but statistically significant increase in the average renal clearance of the drug wb/ch resulted in a reduction of = 18% in the AUC. Total urinary excretion of ofloxacin was not influenced by changes in urinary pH and remained constant at = 81-83% of the adst{nistered dose. No ofloxacin related crystalluria was observed under any of the pH conditions. Investigations performed elsewhere using higher doses of ofloxacin (up to 400mg IV) w~thout pH control have also revealed no evidence of crystalluria. A.W. Pidgen. Clinical Pharmacology Department, Hoechst UK Ltd, Walton Manor, Walton, Milton Keynes, MK7 7AJ, England

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PLASMA AND URINE PHARMACOKINETICS OF RUFLOXACIN IN HEALTHY VOLUNTEERS AFTER SINGLE AND MULTIPLE ORAL DOSES

ABSENCE OF CRYSTALLURIAAFTER OFLOXACIN IN HEALTHY VOLUNTEERS A. KornI~ M. Badian2~ V. Malerzcyk2~ K.-H.Lehr2• A. Mayr2~ P. Balcke1~ W. WaldhAus~I

G. Setre, D. Cerretani, L. Moltoni, R. Urso Plasma and urine kinetics of Rufloxaein (Mediolanum, Milan, Italy), a new fluoroquinolone displaying a broad antibacte rial spectrum,was assessed in healthy volunteers after four single doses (i00, 200, 400 and 800 mg in 6 subjects) and after multiple oral doses (group A: 300 mg followed by 150 mg daily in ii subjects for 5 days; group B: 400 mg followed by 200 mg daily in 4 subjects for 5 days).A tri-exponential model was fitted to the mean drug plasma levels: x(t) = -1.7 e

-2t

+ 0.8 e

-O.15t

+ 0.9 e

-O.007t

being

x = mcg/ml, t = hours and the coefficients of the equation normalized to a i00 mg dose. Peak concentrations normalized to a I00 mg dose were i.i mcg/ml and renal clearances ranged from .6 to 1.2 L/h. The terminal half-life was of 60-90 hours. After multiple oral doses, plasma levels ranged from 0,7 (minimum value) to 19.8 and35.8 mcg/ml (peak concentra tions) in groups A and B, respectively.Urines were collected from time 0 to day 5 after the last dose and in this time interval 35% of the total dose of Rufloxacin was reco vered unmodified in urine. Plasma concentrations of Rufloxa cin were still detectable in both groups 72 hours after the last dose.

Istituto di Farmacologia, Laboratorio di Farmacocinetica, Universit& diSiena, Via Delle Scotte 6, 53100 Siena, Italy

Department of Medicine I, University Hospital, Vienna, Austria I, Clinical Research, Hoechst AG, Frankfurt a.M., FRG2 Ofloxacin (Tarivid(R)) is a new quinolone carboxylic acid derivative with a broad antimicrobial spectrum. Crystalluria has been described after use of quinolones. As ofloxacin is mainly eliminated through the kidney the potential risk of drug-induced crystalluria was assessed in healthy volunteers. Single doses of ofloxacin (100, 200, 300 and 400 mg) were infused over 30 min to 4 groups of 10 subjects. A placebo double-blind, cross-over study with 400 mg ofloxacin was carried out in additional 8 subjects. Diet and fluid intake were standardized on dosing days. Urine was collected in 4-hour fractions for 12 h and thereafter in different periods up to 96 h. Fresh urine samples were collected intermittently for immediate microscopical analysis of sediments. Urine volume and pH were measured. Ofloxacin concentrations were analysed by HPLC. Neither crystalluria nor drug related changes were detected in any of the samples examined. Urinary pH varied between 5.0 and 7.4. Investigations of pH dependent ofloxacin excretion performed elsewhere have revealed no evidence of crystalluria. With ofloxacin doses of 100 mg effective urinary concentrations were found up to the last urine fraction collected (48 h) and peak urinary concentrations after 400 mg were 396 + 286 mg/l. Thus we found no evidence of crystalluria at doses which produced ofloxacin concentrations that are clearly above minimum inhibitory concentrations for most relevant pathogens. Clinical use of ofloxacin is therefore safe regarding drug induced crystalluria. A. Korn, I. Med. Univ.-Klinik, Lazarettg. 14, A-I090 Wien

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AN O P E N T R I A L OF O F L O X A C I N IN N I G E R I A A . F . B . M a b a d e j e r S.B. O s i t e l u and T . O d u g b e m i Twenty-five patients aged 8 - 84 years (mean 51.48) comprising 14 males aged 8 - 84 years (mean 54.9) and 11 females aged 22 - 80 years (mean 47.I) were treated for various infections with the new quinolone - carboxylic acid antibiotic - ofloxacin. Baseline investigations included specimens from sites of infection and blood for haematological and biochemical profiles. The specimens were cultured on MacConkey, Nutrient and Blood agar plates. The isolates were identified according to standard methods. In addition those that were Enterobacteriaceae were confirmed using Enterotube II Roche (Hoffmann - La Roche & Co Ltd., Basle, Switzerland). The bacterial isolates from mid-stream urine samples were tested against antimicrobial discs using the disc - diffusion technique. The antimicrobial discs used were Multo-disc U4(Oxoid), Multo-disc 1789E (Oxoid] and Ofloxacin ("Tarivid") sensitivity disc (Oxoid] distributed by Hoeehst AG. After 18 - 20h incubation at 37~ the inhibition zones were compared with those from control organisms Escherichia coli NCTC 10418 and Staphylococcus aureus NCTC 6571. ~here organisms were sensitive to ofloxacin it was given as tablets at a dose of 200mg every 12 hours except in the case of the 8 year old boy where half dose was given. Specimens were repeated on Day 3, 7 and a day after stopping treatment. Haematological and biochemical profiles were repeated on blood taken the day after treatment was stopped. 11 patients had previous failed antibacterial treatment and 14 had no previous treatment. 25 organisms were isolated from 20 patients. All 25 patients were cured clinically from lower urinary tract infection (22), pelvic inflammatory disease (2) and bronchitis (I). 18 out of 20 patients (90%) had bacteriological cure. Side effects occurred in two patients and comprised drowsiness and metallic taste with nausea. Departments of Pharmacology, Medicine and Microbiology, Lagos University Teaching Hospital, Lagos, Nigeria.

ERADICATION OF RECURRENT SALMONELLA TYPHI MURIUM INFECTION WITH CIPROFLOXACIN IN A P A T I E N T W I T H CHRONIC GRANULOMA~OUS DISEASE F.Gutzler, K.Gmelin, G,M.Haensch and B.Kommerell Patients with a chronic granulomatous disease (CGD) h a v e d e f e c t s of t h e N A D P H - o x i d a s e s y s t e m of the polymorphonuclear leukocytes (PMN). B e c a u s e of t h e d e f e c t i v e p r o d u c t i o n of h y d r o g e n p e r o x i d e during phagocytosis of b a c t e r i a , t h e s e p a t i e n t s a r e p r o n e to r e c u r r e n t i n f e c t i o n s w i t h f a c u l t a tive intracellular bacteria (e.g. s t a p h y l o c o c c i , salmonellae). A 2 3 - y e a r - o l d w o m a n h a d a~ 2 y e a r s h i s t o r y of rec u r r e n t s e p t i c e p i s o d e s d u e to s a l m o n e l l a t y p h i m u r i u m b e c a u s e of a C G D d u e to a p a r t i a l d e f e c t of t h e m e m b r a n e - b o u n d c y t o c h r o m B 245 of t h e P M N (5 % a c t i v i t y of n o r m a l s ) . V a r i o u s b e t a l a c t a m antibiotics did not achieve complete remission. Aft e r a t r e a t m e n t of 250 m g ciprofloxaein b . i . d . f o r 3 m o n t h s it w a s p o s s i b i e to e r a d i c a t e t h e salmonellae. T h e r e f o r e t h e i n t e r a c t i o n of t h e quinolones ciprofloxacin, pefloxacin and oflox a c i n (Q's) w i t h t h e P M N of t h e p a t i e n t a n d of h e a l t h y v o l u n t e e r s w a s s t u d i e d in v i t r o . P M N w e r e i s o l a t e d by d e n s i t y g r a d i e n t c e n t r i f u g a t i o n from heparinized b l o o d . T h e u p t a k e of t h e a n t i b i o t i c s i n t o t h e c e l l s w a s s t u d i e d by u s i n g r a d i o l a b e l l e d compounds and confirmed by a HPLC assay. There w a s a r a p i d u p t a k e of t h e Q ' s b y t h e P M N w i t h i n a f e w s e c o n d s . In c o n t r a s t to p r e v i o u s s t u d i e s the intracellular /extracellular r a t i o (C/E) w a s d e t e r m i n e d as 1 • 0.1 f o r all t e s t e d Q ' s . T h e h y drogen peroxide production of t h e s t i m u l a t e d P M N f r o m t h e p a t i e n t w a s n o t i m p r o v e d b y Q ' s in c o n centrations f r o m 0 . 0 1 to 50 m g / l . O u r r e s u l t s s u g g e s t t h a t Q ' s a r e a b l e to c u r e s a l m o n e l l a i n f e c t i o n s d u e to an i n t r a c e l l u l a r killing despite defective PMN functions. Medizinische Klinik der Universit~t Heidelberg; B e r g h e i m e r S t r a B e 58, D - 6 9 0 0 H e i d e l b e r g , F.R.G.

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ENOXACIN IN THE TREATMENT OF BACTERIAL PEOSTATOVESICULITIS F. Mantovani, E. Mascheroni, M.L. Dal P r ~ E. Montanari, A. Mandressi E. Austoni, E. Pisani Thirtythree patients suffering from acute, subacute or chronic prostatovesiculitis were admitted to an open, non comparative trial. Enoxacin was administered at the daily dosage of 400 mg every 12 hours for I0 days starting from the enrollment. A second cycle of treatment was performed if cure was not obtained with the first cycle. Treatment efficacy was established by assessing patient symptoms related to the infection, such as pollakiuria and dysuria, consistence and volume of prostate and spermatic vesicles (evaluated by rectal examination and transrectal ultra-sonography); bacterioscopical and bacteriological evaluationa of prostate/vesicles secretion with sensitivity testing were also carried out. All observations were collected at baseline, 5 a n d 30 days after the end of the Ist cycle and 5 days after the end of the 2nd cycle of treatment. After the first cycle of treatment, cure was obtained in 22 subjects (67%) and clinical improvement in 2a (78%). All but one patients still infected at the end of the first treatment period, showed improvement (5,a5.5%) or cure (6,54.5%) by the end of the second cycle. None of the 22 patients cu red with one cycle of treatment relapsed within 30 days after the end of treatment, confirming they really achieved cure. Side effects were observed only in 1 case (mild vertigo); no drop outs were observed. These results suggest that enoxacin may be successFully used in the treatment of prostatovesieulitis. Inst. of Urology and Hygiene of Milan University, Via della Commenda, 15, 20100 Milan and Medical Department of Recordati S.p.A., Via M. civitali, i, 20148 Milan, Italy

EFFECT OF CIPROFLOXACIN ON TESTOSTERONE CONCENTRATIONS IN HEALTHY MALES D.J. Edwards, N.M. Waite, W.S. Arnott and L.H. Warbasse Cipre o x e n h-as--be-~how~o in~it th~i~tive metabolism of a number of substrates. Compounds with similar effects on oxidative metabolism such as ketoconazole and eimatidine have been found to inhibit testosterone synthesis and decrease serum concentrations. This has resulted in adverse effects such as gynecomastia and decreased spermatogenesis as well as therapeutic use in decreasing testosterone concentration. The purpose of this study was to examine the effect of ciprofloxacin on testosterone concentration in healthy males. Eight volunteers (23 years old) received ciprofloxacin 500 mg orally twice daily (0800 and 2000) for four days. Blood samples were collected at 0,2,4,6,8 and 12 hours starting at 0800 one day prior to ciprofloxacin. Samples were obtained at the same times after the first and final doses of ciprofloxacin. For comparison, one subject received a single dose of ketoconazole 400 mg orally two weeks after ciprofloxacin with blood samples collected over 12 hours. Serum testosterone concentrations were measured by radioimmunoassay (Diagnostic Products Corporation). Testosterone concentrations under control conditions were not significantly different (NS) from those after the first or final dose of ciprofloxacin at any time point. The area under the serum testosterone concentration-time curve (AUC) over the 12 hour study period averaged 60.6 ng*hr/ml under control conditions, 66.3 ng*hr/ml following the first dose and 59.9 ng*hr/ml following the final dose of ciprofloxacin (NS). In the subject who received ketoconazole, testosterone concentrations decreased to a minimum at 6 hours (23% of the baseline value) and returned to only 35% of baseline at 12 hours. Testosterone AUC decreased from 79.0 to 34.2 ng*br/ml (56.7% decrease) following ketoconazele. These results suggest that ciprofloxacin has no significant effect on serum testosterone concentration after single or multiple dose treatment and is unlikely to have either antiandrogenic side effects or clinical utility in lowering testosterone concentration. Department of Pharmacy Practice, Wayne State University, Detroit, MI 48202

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PHASE I TRIAL OF ANTI-CYTOMEGALOVIRUSHUMANMONOCLONAL ANTIBODY: SAFETY AND MONITORING OF PLASMA LEVEL IN NORMAL HFALTBY MALE VOLUNTEERS. J. Azuma, N. Mochi~uki, S. Sawada and M. M~Lsuzaki C2tomegalovirus(CMV)infec~ion,frequently occurs in compromised hosts,has a high incidence of morbidity and mortality. Chemotherapy of the patients with s infection has not been successful so far. High %itred immunoglobulin has been reported to be effective. Therefore, clinical use of monoclonal antibod~(MCA)having e• high neutralizing activity has been expected. We performed Phase I trial of TI-23(K, IgGI), anti-CMV human MCA, which recognizes sugar protein on the enve]ope(130K,55K). The ED50 value for in vitro neutralization ranges from O.l~g/ml to 0.5#~/ml for ]0 clinical viral isolates. TI-23 was intravenousl~ infused into 16 healthy volunteers: 5mg to 2 volunteers, ]Omg to 2, 20mg to 4, 40mg to 4 and 80mg to 4, respectively. Plasma concentration of TI-23 was measured by ELIZA using anti-idiotype antibody. When 5,10,20 and 40mg were administered, plasma levels immediately after infusion reached 1.3, 3.5, 7.1 and 12.9~g/ml respectively. Plasma levels iweek after infusion s t i l l ensured sufficient neutralizing activity in vitro. Half l i f e time in plasma was calculated to be 23.7 da~s. Antibody which binds to TI-23 was not detected in the plasma of all volunteers. No side effect was observed in these volunteers. From these results, we confirmed that the use of TI-23 is safe and enough to keep the plasma concentration as much as it neutralized CMV in vitro. The 3rd Department of Internal Medicine, Osaka University Medical School. 1-1-50,Fukushima, Osaka 553, JAPAN. Osaka Pharmacology Research Clinic. The ]st Development Department, Pharmaceuticals Division Teijin Limited. Chemical and Biomedical Research Department, Teijin Institute for Biomedical Research.

A DECADE OF ANTIMICROBIAL UTILISATION IN HOSPITALISED PATIENTS J.S. Bapna, Uma Teknr, D.G. Shewade, C. Adithan, S.Zutshi D. Pachiappan C.H. Shahindran and S.C. Pradhan. A retrospective antimicrobial utilisation study using C.M. Kunins criteria (Ann. Int. Med. 19, 555, 1973) was conducted in 1658 hospitalised patients during a one month period in 1977 (N. Viswanathan et al Indian J.Med. Res. 74, 772, 1981). After a gap of a decade a replicate study in 2008 patients has been conducted. The study reveals a vast change in the pattern of use of antimicrobial agents. Streptopenicillin was the commonest drug used a decade ago but now ampicillin has taken its place. The use of antimicrobials has increased from 19.9 to 56.1%. There has been an increase in appropriate use of these drugs from 50 to 88.2%. However, the inappropriate use for prophylaxis of common cold, gastroenteritis and some surgical cases has been on an increase. This study shewed an increase in the resistant strains of P. aeruginosa and Staph aureus to commonly prescribed antimicrobial agents. It is concluded that the antimicrobials are being used more frequently. There has been an increase in their ration/lized use.

Department of Pharmacology, Jawaharlal Institute of Postgraduate Medical Education & Research, Pondieherry 605 006, India.

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FACTORS DETERMINING THE PENETRATIONOF ANTIBIOTICS INTO THE PANCREAS Drewelow, 8., Koch, K., Liebe, S., Riethling, A.-K.

REC 15/2375, A NEW CALCIUM ANTAGONIST: RESULTS OF FIRST CLINICAL TRIALS.

Systematic investigations on penetration of antibiotics into the pancreas are not available. It is also unknown which factors determine the degree of penetration of chemotherapeutics into pancreatic juice and tissue. Knowledge about this would be important for selection of antibiotics to prevent livethreatening septic complications in acute pancreatitis in the pharmacokinetic point of

view. We have studied the permeation of 9 chemotherapeutic agents (Ampicillin, Azlocillin, Mezlocillin, Cefotiam, Gentamicin, Uoxycyclin, Chloramphenicol, Metconidazol, Ciprofloxacin) into the pancreatic juice and tissue in dogs, rats, and patients. The human tissue was obtained from surgical resectates in cases of chronic pancrealitis; human pancreatic juice was collected from pancreatic fistulas and by means of endoscopic cannulaiion of the pancreatic duct. We found a positive linear correlation between natural logarithm of the n-octanol-weter-distribution coefficient (L-value) of antibiotics and their permeation rate in pancr@atic juice and tissue, except ciprofloxacin (good penetration; low L-value). There was an excellent correlation (r=0.988) between relative volume of distribution and permeation rate inclusive of ciprofloxacin. Relations among penetration and moleculare weight, and protein binding rate, respectively, were not found. In cases of acute necrotizing pancreatitis no higher permeation rates were observed. CDNGLUSION: The relative volume of distcibution is the eest parameter for the prognostic assessment of the pancreatic penetration of antibiotics. Abteilung Klinische Pharmakologie des Instituts fgr Pharmakologie und Toxikologie des Bereiches Medizin der Wilhelm-Pieck-Universit~t, Leninallee 70, 2500 Rostock, DOR

REC 15/2375 is a new calcium antagonist of the dihydropy~ ridine class, which in pro-clinical studies has shown a powerful antihypertensive effect, with no negative inotro pism and only a very mild reflex s In a double-blind, cohtrOlled vs, placebo, single ascending dose trial, REC 15/2375 was administered to 16 healthy volunteers and was well tolerated up to 30 mg. In a second study, S patients suffering from mild~oderate essential arterial hypertension were administered 3 different single doses (10,20,30 mg) of REC 15/2375 and placebo according to a double-blind, cross-over design, in order to evaluate REC 15/2375 activity. The following events were observed: I) a dose dependent decrease of systolic blood pressure with 20 and 30 mK significantly different from placebo;2) a dose'dependent decz~ease of diastolic blood pressure with 2 0 and 30 mg significantly different from placebo; 3) a dose dependent increase of heart rate, which was significantly different from p~aceb~ only in the supine position for the three doses; 4) a decrease of PEP and LVET and increase of SV, CO and EDV at the impedance cardiography; 5) minor changes at ECG due to the increased heart rate; 6) no significant changes of laboratory tests; 7) minor side-effects (polyuri~, flush and toredsess) of dose related entity. These results suggest that EEC 15/2375, administered in single doses of 10,20 and 30 mg, is really endowed with antihypertensive properties in man. Recordati S.p.A. - Medical Department, Via M. Civitali I, 20140 Milan, Italy and IKP/AKP - Grunstadt - West Germany

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RO 40-59671 A CALCIUM ANTAGONI{T OF A NEW gENERATION? R. Schmitt , C.H. Kleinbloesem , G.G. Belz Ro 40-5967 is a novel Ca-antagonist that belongs to a new chemical class. Although the drug binds to the verapamil receptor in vitro, it is devoid of negative inotropic properties. In addition, Ro 40-5967 has a favorable pharmacokinetic profile in animals. The purpose of the present study was to investigate the haemodynamic effects of Ro 40-5967 in healthy male volunteers. Single ascending doses of 10,20,40,80,120,160,240 and 320 mg as drinking solution were given to 72 subjects in a double-blind, randomized placebo controlled way with 6 subjects on Ro 405967 and 3 on placebo per dose level. Blood pressure (BP), heart rate (HR) and cardiac output (CO) were measured repeatedly and total peripheral resistance (TPR) was calculated. Electrocardiogram (ECG) and systolic time intervals (STI) were also recorded. At 240 mg maximal effects were seen, occurring between 1 and 3 hr after dosing and not returning to baseline within 12 hr after dosing. Peak effects included a mean decrease in diastol{c BP by 8 mm Hg and a reduction in TPR by 284 dyn sec cm , whereas HR remained almost unchanged. The PQ-time was prolonged by 61 millisec. A steep dose response relationship was seen for the haemodynamic effects with a minimal effective dose of 80-120 mg. Mild adverse events (AE) like flush, headache and nasal congestion were seen at all dose levels, as well as after placebo. Clinically relevant AE included AV-bloek II degree in 2 subjects after 240 and 320 mg and syncope in 1 subject after 320 mg. All AE were transient. From the results of the present study it was concluded that Ro 405967 was well tolerated in dosages up to 160 mg. Higher dosages could result in AV-block. The drug decreased BP dose dependently by reduction of TPR, but no reflex tachycardia was observed. There was no evidence for negative inotropism. 1 Pharma Clinical Research Hoffmann-La Roche & Co Ltd. CH-4002 Basel 2 Zentrum f~r kardiovaskulare Therapie, D-6200 Wiesbaden

P L E N D I L | IN C O M B I N A T I O N W I T H M E T O P R O L O L CR IN T H E T R E A T M E N T OF H Y P E R T E N S I O N . F o r t h e S w e d i s h M u l t i c e n t e r S t u d y Group, J o h a n Brun. A n e x t e n d e d r e l e a s e f o r m u l a t i o n of f e l o d i p i n e (Plendil | , Astra Cardiovascular) enables once d a i l y a d m i n i s t r a t i o n of this d i h y d r o p y r i d i n e Ca-antagonist. In a r a n d o m i s e d , d o u b l e - b l i n d , p l a c e b o c o n t r o l l e d , p a r a l l e l g r o u p study the d o s e r e s p o n s e r e l a t i o n s h i p a n d t o l e r a b i l i t y of P l e n d i l | {5, lO, 20 mg o n c e daily) w e r e e v a l u a t e d w h e n c o m b i n e d w i t h m e t o p r o l o l CR i00 mg once daily. Two h u n d r e d and f i f t y - o n e p a t i e n t s (251) w i t h s u p i n e d i a s t o l i c b l b o d p r e s s u r e (DBP) >95 m m Hg after a 4 w e e k r u n - i n p e r i o d on p l a c e b o and m e t o p r o l o ! C R i00 mg w e r e s t u d i e d . A f t e r 4 weeks' d o u b l e - b l i n d t r e a t m e n t t h e BP r e d u c t i o n f r o m b a s e l i n e in each of the P l e n d i l | g r o u p s was s i g n i f i c a n t l y g r e a t e r t h a n t h a t in the p l a c e b o group. The d i f f e r e n c e s in r e d u c t i o n s ( c o m p a r e d w i t h p l a c e b o ) 2 (24) h o u r s a f t e r dose, w e r e 9/5 (5/3) m m H g on 5 mg Plendil | 17/9 (9/6) m m Hg o n i0 m g P l e n d i l | a n d 1 8 / 1 2 (9/7) m m H g on 20 mg. T w e l v e p a t i e n t s w e r e w i t h d r a w n due to a d v e r s e e x p e r i e n c e s , (i, i, 4 a n d 6 p a t i e n t s the p l a c e b o , 5, I0 a h d 20 m g P l e n d i l | groups, respectively). C o n c l u s i o n : In this g r o u p of h y p e r t e n s i v e p a t i e n t s , not w e l l c o n t r o l l e d by m e t o p r o l o l C R i00 m g o n c e daily, the o p t i m a l d o s e of P l e n d i l | w a s i0 mg once daily, since it was b o t h h i g h l y e f f e c t i v e and w e l l t o l e r a t e d .

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P H A S E - I E V A L U A T I O N OF D I P E R D I P I N E , A N E W D I H Y D R O PYRIDINE CALCIUM CHANNEL BLOCKER M. C u p r u n o v , T. Thomsen, P. Fink*, I. R o o t s Animak experiments showed a similar pharmacological e f f i c i e n c y of d i p e r d i p i n e (YS 201; e t h y l - 2 (l-piperidino)ethyl-l,4-dihydro-2,6-dimethyl-4(3-nitrophenyl)-3,5-p~[idine dicarboxylate hydroc h l o r i d e ) as o t h e r C a - - c h a n n e l b l o c k e r s of the d i h y d r o p y r i d i n e t y p e s u c h as n i f e d i p i n e , n i c a r d i pine, or n i t r e n d i p i n e . T h e t o l e r a n c e of this n e w s u b s t a n c e w a s e v a l u a t e d in 39 m a l e h e a l t h y v o l u n t e e r s (age r a n g e 24-39 years) w i t h four p h a s e - I studies: A. 21 v o l u n t e e r s r e c e i v e d two s i n g l e o r a l d o s e s b e t w e e n i0 a n d 80 m g at two s e p a r a t e days. B. 7 v o l u n t e e r s of s t u d y A r e c e i v e d o n e or two 3 0 - m i n - i . v . i n f u s i o n s of 2 m g to 20 m g of d i p e r d i p i n e . C. 5 v o l u n t e e r s w e r e a p p l i c a t e d 20 m g d i p e r d i p i n e t.i.d, on five days. D. 12 v o l u n t e e r s t o o k p a r t in a d o u b l e b l i n d p l a c e b o - c o n t r o l l e d c r o s s - o v e r s t u d y w i t h an a p p l i c a t i o n of 25 m g dip e r d i p i n e t.i.d, or p l a c e b o for two p e r i o d s of f o u r t e e n d a y s each. G e n e r a l t o l e r a n c e , p u l s e rate, b l o o d p r e s s u r e , ECG, a n d l a b o r a t o r y p a r a m e ters w e r e r e g u l a r i l y m o n i t o r e d . D i p e r d i p i n e w a s g e n e r a l l y w e l l t o l e r a t e d . T y p i c a l u n w a n t e d effects l i k e h e a d a c h e a n d t i r e d n e s s o c c u r r e d d o s e d e p e n d e n t l y in the m a j o r i t y of the v o l u n t e e r s . Partly, v o l u n t e e r s r e s p o n d e d w i t h l o w e r i n g of sys t o l i c a n d d i a s t o l i c b l o o d p r e s s u r e as w e l l as with bradycardia, with a maximal effect mostly 2 to 3 h o u r s a f t e r dosing. A - V c o n d u c t i o n t i m e rem a i n e d m o s t l y u n a f f e c t e d , o n l y in t h r e e v o l u n teers an a b o u t 15 % i n c r e a s e w a s o b s e r v e d . T h e studies show that diperdipina might comprise hyD o t e n s i v e e f f e c t s of n i f e d i p i n e a n d b r a d y c a r d i c e f f e c t s of v e r a p a m i l , b u t w i t h l i t t l e i n f l u e n c e on A - V c o n d u c t i o n . I n s t i t u t for Klin. P h a r m a k o l o g i e , K l i n i k u m Steglitz, F r e i e U n i v e r s i t ~ t Berlin, H i n d e n b u r g d a m m 30, D - 1 0 0 0 B e r l i n 45; * H e n n i n g B e r l i n G m b H

C O M P E R I S O N O F T H E R E S P O N S E S O F T H E R A T SUPERIOR M E S E N T E R I C A R T E R Y T O NITRENDIPINE A N D D I L T I A Z E M S. K . Krsti6~ M . K. Krsti6 and Z. S. Katu~i6 Endothelial cells can release endothelium-derived relaxant factor (s) (R. Furchgott , Annu. Rev. Pharmacol. Toxicol. 24~ 175~ 1984)~ which m a y modulate vascular reactivity to various vasoactive agents. Therefore ~ it w a s of interest to establish whether the endothelial cells of the rat superior mesenteric artery play any role in the mediation of its responses to nitrendipine and diltiazem. M o r e o v e r ~ the responses of the artery to these calcium antagonists w e r e c o m pared. The experiments w e r e Performed on rings (4 m m long) of the artery suspended in Krebs-Ringer-bicarbonate solution gassed with 9 5 % O _ - 5 % C O ^ mixture and kept at 37 ~ C. In s o m e rings the endothelium w a s mechanically r e m o ved. Isometric tension w a s continuosly recorded. Both nitrendipine and diltiazem caused concentration-dependent relaxations in rings of the artery contracted by norepinephrine or K , The nitrendipine-induced relaxations w e r e comparable with those induced by diitiazem o Sensitivity of the artery contracted with K + to the relaxant effect of the calcium antagonists w a s significantly higher as c o m p a r e d to sensitivity of the artery contracted with norepinephrine. Removal of the vascular endothelium did not affect the inhibitory effects of the calcium antagonists. These results indicate that nitrendipine and diltiazem cause a relaxation of the rat superior mesenteric artery which is not modulated by the presence of intact endothelial cells o In addition~ nitrendipine and diltiazem possess equally potent calcium antagonistic activities in the rat superior mesenteric artery. Department of Pharmacology~ Faculty of Medicine P.O. Box 662~ II000 Belgrade ~ Yugoslavia

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RANDOMIZED,

DIFFERENT TREATMENT 0. Mayer~

DOUELE-BLIND cOMPARISON OF GALLOPAMIL AND

NIFEDIPINE IN S~ABLE ANGINA PECTORIS M. BraZil, K. Birtid, H. Jeri~, @D. Davila, F. Pla~i6,

D. Vukosavi6 and D. Planinc

The efficacy of gallopamil in comparison with ~}ifedipine in stable angina pectoris was investigated in randomized, double-blind, placebo-controlled crossover study in 38 patients of both sexes. After one week of placebo run-in (taking nitroglycerin) in tke subsequent four weeks all patients were administered cral]y 150 mg of gallopamil (50 mg t.i.d.) or 30 mg of nifedivine (10 mg t.i.d.). The systolic and diastolic pressure decreased significantly with gallopamil and nifedipine Jn relation to placebo period. Gallopamil significantly reduced heart rate in comparison to nifedipi~e. Number of anginal attacks in one week was reduced from 5.5 to 2.1 and 5.5 to 2.3 after four weeks of gallopamil and nifedipine treatment, respectively. Statistically significant reduction in weekly nitroglycerin consumption was also recorded. It dropped from 5.6 to 1.7 sublingual tablets after gallopamil treatment and from 5.6 to 2.3 after nifedipine. The average exercise time increased from 6.2 to 8.2 minutes and from 6.2 to 7.5 minutes after gallepami] and oifedipine treatment, respectively. There was no significant differences in the incidence of recorded side effects with both tested drugs or placebo. Headache ~as the only side effect that was recorded more frequently after use of nifedipine compared to gallopamil or placebo. These results indicate that gallopamil exerted good effect in patients with stable angina pectoris. @Pliva Research Institute and Clinic Hospital "Dr Mladen Stojanovi6", Zagreb, Yugoslavia

TYPES OF C A L C I U M A N T A G O N I S T S OF H Y P E R I E N S I O N H. P o l i v k o v ~ J. R o t t e n b o r n

IN THE

The aim o f t h e s t u d y was t o e v a l u a t e the eff+ i o a c y and s a f e t y of two dihydropyridine calcium antagonists and o f d i l t i a z e m which are used in the treatment of hypertension in Czechoslovakia. On t h a t o c c a s i o n d i f f e r e n t drug preparation forms were tested. The c o m p a r i s o n was p e r f o r m e d either as a c r o s s o v e r s t u d y i n t h e same s u b j e c t as i n d i f f e r e n t patients. Nifedipine was a d m i n i s t e r e d randomly in slow ralease o r non r e t a r d e d f a r m . T h e r e was a s a t i sfactory control of blood pressure with both preparations. Isradipine (Lomir Sandoz), the second dihydropyridine derivative was r e s t e d i n a n o t h e r group. This drug revealed a good a n t i h y p e r t e n s i ve e f f e c t . Two b r a n d s o f d i l t i a z e m were rested - czechoslovak preparation compared with Bilzem GSdecke. I n some p a t i e n t s the continuation of the treatment was p e r f o r m e d w i t h s l o w r e l e a s e farm. A good c o n t r o l of hypertension was seen w i t h a l l tested preparations. The r e s p o n s e was t e s t e d using bicyble exercise t e s t i n a l l s t u d i e s b e f o r e and a f t e r treatment. In general calcium antagonists led to a reduction in diastolic blood pressure increase during exercise. Although the dihydropyridine are considered t o be a d v a n t a g e o u s i n a n f i h y p e r f e n s i v e treatment due t o t h e i r purely vascular effect, our observations showed no s i g n i f i c a n t differences in all tested drugs. Department of Clinical Pharmacology, University Hospital, M a r x o v a 1 3 , 305 99 P l z e f i / C z e c h o s l o v a kia.

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HEMODYNAMIC EFFECTS OF DILTIAZEM AND NITRENDIPINE 1 2 . 2 P. Dylew~cz , A. Halabi , M. Llnde , H. S a a t h o f f 2, W. K i r c h ~tiazem, verapamil and n i f e d i p i n e are h i g h l y s p e c i f i c calcium a n t a g o n i s t s . N i t r e n d i p l n e i s a newer calcium ant a g o n i s t o f t h e d i h y d r o p y r i d i n e group. As calcium antagon i s t s e x e r t n e g a t i v e i n o t r o p i c i n f l u e n c e s which are count e r a c t e d by t h e i r v a s o d i l a t i n g p r o p e r t i e s , aim o f t h e present study was t o compare the hemadynamic e f f e c t s o f d i l tiazem and n i t r e n d i p i n e . During a randomized, placebo-cont r o l l e d d o u b l e - b l i n d crossover study 16 p a t i e n t s w i t h cong e s t i v e h e a r t f a i l u r e (NYHA stage I I ; 12 male, 4 female; mean age 60.2 + 9.8 y r s ; b.w. 77.8 + 13.9 kg; X + SD) were t r e a t e d w i t h s~ngle o r a l doses o f piacebo, go and 180 mg d i l t i a z e m as w e l l as 20 and 40 mg n i t r e n d i p i n e on f i v e d i f f e r e n t occasions. Before, 3,6, and 12 hrs a f t e r dosing s y s t o l i c time i n t e r v a l s , impedance cardiography and venous occlusion plethysmography were measured as n o n - i n v a s i v e hemodynamic parameters. In impedance cardiography 3 , 6 , and 12 hrs a f t e r t r e a t m e n t go and 160 mg d i l t i a z e m , but not n i t r e n d i p i n e on doses o f 20 and 40 mg, led t o a s i g n i f i cant increase o f t h e s t r o k e volume (AV) compared t o p l a cebo values. Cardiac output (C.O.) was not s i g n i f i c a n t i y increased by any o f t h e drugs or doses administered. Parameters o f s y s t o l i c time i n t e r v a I s as p r e a j e c t i o n period (PEPs) and PEP/LVET were more d i s t i n c t l y reduced on d i l tiazem than on n i t r e n d i p i n e , r e s u l t s which are i n agreement w i t h the impedance c a r d l o g r a p h i c data. I n conclusion, in both doses administered d i l t i a z e m had a more f a v o u r a b l e i n f l u e n c e on t h e hemadynamic parameters measured in pat i e n t s w i t h congestive h e a r t f a i l u r e than n i t r e n d i p i n e . This may be p a r t l c due t o the f a c t t h a t d i l t i a z e m s l i g h t l y decreases h e a r t r a t e , whereas n i t r e n d i p i n e has the opposite influence. Dept. ~ f C a r d i o l o g y , U n i v e r s i t y Medical School, Poznan, PolandI. Medizinische Klinik, Christian-Aib~echts-Universit~t, S c h i t t e n h e l m s t r . 12, D-2300 K i e l , FRG~.

A C O M P A R I S O N OF TWO L O N G - A C T I N G C A L C I U M ANTGONIST, BEPRIDIL AND NISOLDIPINE, ON THE S Y S T E M I C AND C O R O N A R Y N E M O D Y N A M I C S AND ON THE PROSTAGLANDIN M E T A B O L I S M IN MAN. A. Kurita, B. Takase, A. Uehata,T. Nishioka,T.Maruyama, H. S u g a w a r a , K. S a t o m u r a , H. Nakamura, Y. Kanda, Y. Yoshino. Nat. D e f e n s e Med. Coll. and N i p p o n Med. School. S a i t a m a and Tokyo, Japan. As b e p r i d i l (BEP) has a high b i n d i n g activity for protein, BEP would seem to h a v e a d i f f e r e n t p h a r m a c o l o g i c a c t i o n than n i s o l d i p i n e (NIS). To assess these two drugs, we compared their effects on the c o r o n a r y and s y s t e m i c hemod y n a m i c s , and on the p r o s t a g l a n d i n (PG) m e t a b o l i s m during s t r e s s in p a t i e n t s (pts) w i t h an ischemic heart d i s e a s e (IHD). 10 IHD pts were studied 2 hr. b e f o r e and after an oral BEP dose (150mg) and a n o t h e r I0 were similarly studied after an oral NIS dose (Smg), after which their plasma 6 Keto PGF~ (6KPG) and t h r o m b o x a n e B ~ ( T X ) l e v e l s were m e a s u r e d by RIA. P l a s m a c o n c e n t r a t i o n s of both drugs w e r e assessed by liquid c h r o m a t o g r a p h y w h i c h s h o w e d 300• 30 n g / m l ~ SD) for BEP and 3 . ~ 3 for NIS. Also, their 'mean b r a c h i s l a r t e r i a l p r e s s u r e (mBAP), and CS flow (CSF) w e r e m e a s u r e d , and coronary v a s c u l a r r e s i s t a n c e (CVR) was d e r i v e d . The m e a n CS p r e s s u r e (mCSP) w a s m e a s u r e d . T h e e f f e c t s of these drugs were c o m p a r e d at rest (R) and during exercise (EX). The r e s u l t s below are % c h a n g e s a f t e r BEP or NIS. mBAP mCSP CSF CVR TX/6KPG BEP, R/EX : -2/-3 -2/9 ~ 4/5 -2/=5 ~ -21/4 NIS, R/EX : -8/-2 - 4 / - 3 5 21/16 - 1 9 / - 1 2 -23/-23 T h e s e r e s u l t s s u g g e s t that BEP was proved to be a s i m i l a r e f f e c t s on s y s t e m i c h e m o d y n a m i c s and PG m e t a b o l i s m to NIS, t h o u g h NIS has more coronary h e m o d y n a m i c effects. p
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ANTIHYPERTENSIVE EFFECTS OF LOW DOSE NISOI@IPINE IN PATIENTS WITH ESSENTI~ HYPERTENSION Y. Abe, H. Shionoiri, E. Gotoh, A. Ikeda, K. Minamisawa, S. Ueda, K. Sugimoto and Y. Kaneko

EFFECTS OF MEALS AND NITRENDIPINE ON SERUM GLUCOSE, INSULIN, GLUCAGON AND NOREPINEPHRINE T. C. Fagan, K. A. Conrad, M. J. Mack• D. G. Johnson, A. L. Mazzu and D. E. Burkholder Meals elevate serum glucose/SG) and insulin (I), and some studies have found increases in norepinephrine (NE). The effects of meals, nitrendipine (N, a dihydropyridine calcium entry blocker) and the combination were evaluated in 21 patients with essential hypertension; 15 male, 6 female, age 22-65, weight 160-226 pounds. In a double-blind, randomized, crossover design, on consecutive days the patients ate a 770 Kcal meal 40% protein, 20% carbohydrate, 40% fat) and a sham meal looked at and smelled the food and watched others eat) at the end of treatment with placebo and with N, 20 mg once daily for 2 weeks. SG, I, NE and glucagon (GN) were measured before (PRE) and one hour after the meals and sham meals (POST).

N1.--~6~ a long-acting ca--gl-C~--umchannel i n h i b i t o r , was administered once d a i l y to nine p a t i e n t s with e s s e n t i a l hypertension. The p a t i e n t s ' averaged blood p r e s s u r e was over ]50/90 mmI{g after at least two biweekly measurements of blood pressure prior to the nisoldipine therapy. After the baseline evaluation was completed, the adminfstraiton of niseldipine (2.5 mg orally, once daily) was initiated and continued for elght weeks. In some patients the nisoldipine dose was titrated upward after eight weeks. To evaluate the duration of the ant• effects of a once-daily dose of nisoldipine, blood pressure at 24 hours after oral aoministration (24-hour valuel and at two hours (2-hour value) were measured every four weeks. At a nisoldipine dose of 2.5 mg~dav, the mean 2-hour values were significantly reduced ~rqm the ~n~tial value of ]62.6!7.5/i01.9!6.4 ~,hHg to 14h.b~b.I/~/.iiZ.J mmHg at week 4 and to ]47.7~9.]/86.0+5.7 mm}{g week 8. The mean 24hour values at weeks 4 and 8 were reduced to ]54.9+ 7.3/ 93.]14.] mmHg and |56.6+7.1/94.9+6.6 mmHg, respectively. With a 5-mg dail X dose of nisoldipine, the mean 2-hohr values were significantly reduced from the initial value =

o~ 1. . . . • Kq

07

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Q mm~

~

11

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~7

~

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.3:90.5 ~.0 .,.,~2.~ - t +q

~.

week 4 and ]43.3!3.7/85.0~2.8 md{g at week 8. Similarly, the mean 24-hour values were reduced to ]54.2J:4.3/93.0f7.2 mmHg at week 4 and ]48.7+3.9/90.3+3.4 mm}{g at week 8. The results of the time courses in blood pressure by dose revealed that reductions were statistically significant in all two-hour values and in a]mest all 24-hour values. These findings suggested that a 2.5-mg or 5-mg daily dose of niseldipine may still maintain ItS ant• action at 14hours after dosing, although the aclton might be weaker than that at two hours after dosing. By using the bleed pressure values at 24 hours after dosing, we intended to reveal whether the ant• effects of nisoldipine lasted for an entire day. By using the blood pressure values at two hours after "dosing we intended to reveal whether nisoldipine exerted adequate antihwertensive effects. Overall, these findings proved that once-daily nisoldipine may have prolonged and adequate ant• action over 24 hours in outpatients. The Second Department of Internal Medicine, Yokohama City University, Japan.

SG mg\dl

I #U/ml

GN pg/ml

NE pg/ml

10• 10• 10i8 67•

260• 263• 248• 302•

297• 284• 261• 305•

i0• 9• 12• 64•

243• 247• 231• 329•

291• 346• 286• 317•

PLACEBO S H A M PRE 102• POST 98• M E A L PRE 107• POST 121•

NITRENDIPINE S H A M PRE 104• POST 99• M E A L PRE 101• POST 120•

Values shown are mean • SD *, p<0.01; **, p<0.001 compared to PRE This mixed meal alone significantly increased SG, I and tended to increase NE without affecting GN. During treatment with N the meal significantly increased SG, I and GN. N alone increased NE 1 hour post dose, probably as a reflex response to vasodilation. N did not affect fasting SG, I or GN, nor did it affect the response of SG and I to the meal, but during treatment with N, GN also increased in response to the meal. Department of Medicine, University of Arizona College of Medicine, 1501 N. Campbell Ave. Tucson, AZ, 85724, USA.

PP 16.35

PP 16.37

EFFECT OF NITRENDIPINE ON HEMODYNAMICS DURING EXERCISE IN PATIENTS WITH EFFORT ANGINA AND OLD MYOCARDIAL INFARCTION S. Kobayashi, T. Saito, K. Makita, Y. Yamazaki, Y. Furukawa, M. Shimizu, K. Yamada, H. Tomiya, K. Takeda and Y. Inagaki A study was made of the effect of nitrendipine on exercise hemodynamics. The subjects were i0 patients with effort angina with old myocardial infarction, who showed significant ischemic ST depression on electrocardiogram during exercise, and who had over 75% stenosis of the main coronary arteries. A dose of i0 mg of nitrendipine was given once a day for 1 week. Before and after treatment, exercise testing was performed using a bicycle ergometer operated in the supine position. Hemodynamic parameters both at rest and during exercise, were measured. The results were as follows: At rest, the blood pressure decreased significantly, the total peripheral resistance and pulmonary artery pressure tended to fall, while the heart rate, left ventricular ejection fraction and cardiac index remained unchanged. During exercise, the blood pressure showed a tendency to fall, the heart rate remained almost unchanged, the cardiac index tended to increase, the rise in pulmonary artery pressure was suppressed significantly, the pulmonary vascular resistance showed a significant decrease, and the fall in left ventricular ejection fraction was significantly reduced. From the above results, it will be seen that the main hemodynamic effect of nitrendipine is a decrease in the after load resulting from the dilatation of peripheral arteries. Since nitrendipine improves both electrocardiographic findings and hemodynamics during exercise in patients with effort angina, it appears to be a useful drug for the treatment of ischemic heart disease. The Third Department of Internal Medicine, Chiba University, School of Medicine, 1-8-1 Inohana, Chiba City, Chiba280, Japan

COMPARATIVE CARDIOVASCULAR EFFECTS OF NIFEDIPINE AND NICARDIPINE MEASURE D BY IMPEDANCE CARDIOGRAPHY S.H.L. Thomas* & S.E. Smith Studies using parenteral preparations show that nifedipine produces a more marked direct negative inotropic effect than nicardipine, but there is some contribution from the nifedipine vehicle solution and the relevance of these findings to oral therapy is not cl ear. In this study, the cardiovascular effects of single oral doses of n i f e d i p i n e (5 mg and i0 mg) and nicardipine (20 mg and 30 mg) were compared with placebo (x 2) in a double-blind crossover study in 8 healthy male volunteers. Two hours following dosage measurement of cardiac output (NCCOM3 (BoMed) impedance cardiograph) and blood pressure were made during passive tilting, exercise (30 - 180 W) and recovery. Both agents increased stroke volume and cardiac index and reduced blood p r e s s u r e and total peripheral resistance (mean BP/cardiac output) at all stages in the experiment. Increases in heart rate were produced by both doses of nifedipine but the only the lower nicardipine dose. Reductions in peripheral resistance were similar for nifedipine i0 mg and nicardipine 20 mg and 30 mg but in these doses slgnificantly larger increases in heart rate were observed with nifediplne, and in s t r o k e v o l u m e and c a r d i a c i n d e x w i t h nicardipine. The differences observed were small but are consistent wlth oral nifedipine having a more marked direct negative inotropic effect in comparison with oral nicardipine. Further studies to examine the effect of oral nifedipine and nicardipine in patients with impaired ventricu]ar function will be helpful to determine whether this difference is of clinical importance. Department of Clinical Pharmacology, United Medical & Dental Schools, St. Thomas' Campus, London SEI 7EH, UK.

A 339

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EFFICACY OF A SUSIAINED RELEASE FORMULATION OF NIEARDIPINE IN HYPERTENSION ASSESSED 8Y CLINIC AND HOME BLOOD PRESSURE RECORDINGS. I. Webster I J.C. Petrie~ T.A. Jeffers, P. Roy-ChaudhuryT W. Crichton, K. Witte M. Jamieson Sixty patients with mild to moderate hypertension were recruited to a randomised~ crossover, placebo-controlled comparison of standard nieardipine (STD) 30mg three times daily versus a sustained release Formulation (SR) 60mg twice daily. Sitting blood pressure (BP) ~ s measured using a Hawksley random zero sphygmomanometer (HRZ) at estimated trough effect (8-15 hr) and peak effect (].5-Z.5 hr) post dose at 14 days and 28 days of the three randomised treatment periods. Between the 24th and the 28th day or each treatment phase, 2-hourly home BP recording was undertaken during waking hours using the Copal UA251 semiautomatic instrument. Results For mean sitting BP (HRZ) are summarised as follows: Plac STD__ SR Plac-STD p Plac-SR p Day 14 151 143 158 8
PHARMACOKINE~ICS O F VERAPAMIL 200 rug SR-TABLET TWICE DAILY S. Nyk~nen, A. J~rvinen and J. Mattila Good control of blood pressure is pursued also d u r i n g night time. To m a i n t a i n adequate serum verapamil levels throughout the dosage interval a 200 m g slow-release tablet for twice daily administration was developed. The pharmacokinetic profile of verapamil 200 lug st-tablet twice daily was studied after a single dose and at steady state and compared to that of once d a i l y administration of 200 m g o r 240 m g sr-tablets. Eleven healthy volunteers completed the study. Serum verapar~l and norverapamml concentrations were analyzed with gas chromatography-mass spectrometry on the first and fifth days from the beginning of the medication. 200 m g tablet was m o r e rapidly absorbed after a single dose than 240 m g tablet (p<0.0~)24No significant difference in the dose-corrected AUC - -values were observed either after a single dose o r at steady state. Mean steady state concentration after 200 m g twice d a i l y (154_+22 ng/ml, mean+sem) was significantly higher than that after 240 m g once daily (75~9 ng/mi) or 200 m g once daily (49~7 ng/ml) as was the case w i t h m o r n i n g trough concentrations (114913, 32• and 22*4 ng/ml, respectively) (p<0.001). Also fluctuation after 200 m g twice daily was significantly lower than that after 200 m g or 240 mg once daily. It can b e concluded that 200 m g verapamil administered twice daily gives higher and m o r e stable serum verapamll levels throughout the dosage interval than once d a i l y administration. The results are in agreement w i t h the finding of better 24-hour control of hypertension w i t h verapamil 200 m g twice daily as compared to once d a i l y administration (Nissinen et el., Eur. J. Clin. Pharmacol. 31, 225, 1986). orion Pharmaceutica, Medical Department, P.O. B o x 65, SF-02101 Espoo, Finland.

9 Day 14

Peak

151 ~6

152 84

128 81

ig 12


2] 15


Day 28 Trough

151 97

140 90

157 90

ii 7


14 7


Day 28 Peak

155 97

133 81

128 79

20 16


25 18

<0.001
In addition, home recordings showed that both formulations reduced BP significantly throughout the monitoring period except For diastolic BP between 5-9 hr after the second daily dose of STD. Unfortunately however, these BP responses were achieved at the expense of troublesome vasodiiator symptoms in a substantial number of patients ~ 14/60 discontinued active therapy as a result (especially flushing, headaches, leg oedema, palpitations, dizziness) while others suffered less severe effects of a similar pattern on active therapy (42 on SR, 38 on STD, 24 on placebo). These results confirm that nicardipine is an effective antibypertensive drug and that this particular SR formulation produces a substantial lowering of BP over 24 hr ahen administered twice daily. The dihydropyridine vasodilator effects at these fixed doses hoaever, remain a serious disadvantage, and dose-titration may be preferable. Department of Medicine & Therapeutics, University of Aberdeen, Polwarth Building, Feresterhili, Aberdeen, U.K.

PP 16.39

PP 16.41

THE EFFECT OF NICARDIPINE ON THE ISOLATED CANINE BASILAR ARTERY M. K o K r s t i 6 and Z . So KatuSi6 The effect of n i c a r d i p i n e was s t u d i e d and c o m p a r e d with t h a t of d i l t i a z e m in r i n g s of i s o l a t e d c a n i n e b a s i l a r a r t e r i e s . The r i n g s with and without e n d o t h e l i u m w e r e s u s p e n d e d for i s o m e t r i c t e n s i o n r e c o r d i n 9 in p h y s i o l o g i c a l s a l t s o l u t i on. The r e m o v a l of e n d o t h e l i u m w a s c o n f i r m e d by t he a b s e n ce of r e l a x a t i o n s i n d u c e d with v a s o p r e s s i n . N i c a r d i p i n e and d i l t i a z e m c a u s e d c o n c e n t r a t i o n - d e p e n d e n t r e l a x a t i o n s in r i n ~ s of th e a r t e r y c o n t r a c t e d with p r o s t a g l a n d i n F2alpha and K-o N i c a r d i p i n e w a s m o r e potent as c o m p a r e d to d i l t i a z e m ~ although the m a x i m a l r e s p o n s e s o b t a i n e d with both d r u g s w e r e i d e n t i c a l . A f t e r r e m o v a l of e n d o t h e l i u m the i n h i b i t o r y effect of n i c a r d i p i n e w a s not a f f e c t e d in th e r i n g s c o n t r a c t e d with K +. H o w e v e r , the i n h i b i t o r y effect of l o w e r c o n c e n t r a t i o n s of n i c a r d i p i n e (10 - 1 0 - 3 x l 0 - d M ) on p r o s t a g i a n d i n F 2 a l p h a - i n d u c e d c o n t r a c t i o n s was s i g n i f i c a n t l y r e d uced in r i n g s without e n d o t h e l i u m . The c o n c e n t r a t i o n s of n i c a r d i p i n e in e x c e s s of 10-7M c a u s e d i d e n t i c a l r e l a x a t i o n s in r i n g s with and without e n d o t h e l i u m d u r i n g c o n t r a c t i o n s e v o k e d by p r o s t a g l a n d i n F 2 a l p h a . These r e s u l t s i n d i c a t e that th e r e l a x a n t effect of n i c a r d i p i n e on the i s o l a t e d c a n i n e b a s i l a r a r t e r y i s m o r e potent than t h a t of d i l t i a z e m , a l t h o ugh the r e l a x a n t effect of both d r u g s iN of the s a m e e f f i c i enCyo The n i c a r d i p i n e - i n d u c e d r e l a x a t i o n i s m a i n l y due to a direct effect on the vascular smooth muscle. In the arteries contracted with prostaglandin F2alpha ~ the relaxant effect of nicardipine appears to be facilitated~ in the lower coneentratons range~ by the presence of the intact endothelial cells. Department of Pharmacology ~ Faculty of Medicine, P.O. box 662~ II000 Belgrade~ Yugoslavia

VERAPAMIL ALTERS PLASMA HUMAN ANP LEVELS IN HYPERTENSIVE PATIENTS L.M.A.B. van Bortel, P.N.H. Schiffers, R.O.B. Bahm, J.M.V. Mooy, K.H. Rahn, and H.A.J. Struyker Boudier

A t r i a l n a t r i u r e t l c p e p t i d e (ANP) i s a p e p t i d e with nat r i u r e t l c , d i u r e t i c and v a s c u l a r smooth muscle r e l a x i n g activity. Its release into the circulation seems to be regulated mainly by atrial distension. This study investigates the effect of a chronic treatment with verapamil on ANP. Plasma human ANP levels were measured in 19 patients with essential hypertension after 30 min of supine rest and after 15 min of head-down tilt (30~ In a double-blind placebo-controlled cross-over study, 9 young patients (YH; 2 F, 7 M; mean age 33~2 y) and i0 elderly patients (EH; 2 F, 8 M; man age 64• y) were given in a randomized order a 120 mg tablet of verapamil or an apparently identical tablet of placebo 3 times daily for 4 weeks. Verapamil decreased blood pressure (BP) from 158•177 mmHg to 145•177 mmHg in EH and from 146•177 mmHg to 147•177 mmHg in YH. At the end of each 4 week period, plasma ANP c o n centrations were measured by radioimmunoassay. During placebo, EH showed a higher plasma ANP level (61.8• pg/ml) than YM (33.4• pg/ml) did (p
University

of

A 340

PP 16.42

PP 16.44

THE INFLUENCE OF VERAPAMIL ON THE PORTAL P R E S S U R E IN E X P E R I M E N T A L A N D C L I N I C A L

ANTIANGINAL EFFECT OF NICORANDIL IN EFFORT ANGINA: CHANGES IN CORONARY AND SYSTEMIC HEMODYNAMICS DURING RAPID PACING STRESS TEST H. OGAWA, M. YAMAGISHI, J. TAMAI, S. KARAKAWA, H. TAKAGI A. KAWAGUCHI, F. ISHIKURA, S. NAGATA, K. MIYATAKE Nicorandil (NCR), a new orally absorptive ant• drug, effectively prevents effort angina as well as rest angina. However, little is known about its efficacy on coronary and systemic hemodynamics during cardiac stress. To examine the effects of NCR on coronary and systemic circulations , the hemodynamic responses to NCR were studied in 16 patients with stable effort angina who had significant organic stenosis in the left anterior descending artery (LAD). Mean arterial pressure (MAP, mmHg), pulmonary arterial end-diastolic pressure (PADP, mmHg), cardiac output (CO) and great cardiac vein flow (GCVF, ml/min: thermodilution method ) were measured during atrial pacing (llO-150/min) before and 15 minutes after oral NCR administration (20 mg). Coronary and systemic resistances (CR and SR, mmHg'min/ml) were calculated by dividing MAP by GCVF and CO, respectively. The cha~ges in diameter of the proximal LAD were determined by digital subtraction angiography. The hemodynamic responses are: MeaniS.D. ( * p
CONDITIONS K. M a c e k , P. HGlek, A. Hlava, A. K r a d i n a . J. M a r t ~ a k o v ~

P. E l i ~ ,

Vasodilators seem to be promising in pharmacological treatment of portal hypertension. Therefore, we investigated the influence o f a calciu~ channel blocker, verspamil, on portal pressure in different eonditiona. In conscious rats the i n f u s i o n o f verapamil produced gradual decrease of blood pressure, prompt decrease o f t o t a l peripheral resistance and did not influence heart rate. Simultaneously the increase of portal pressure st the beginning of infusion followed by sustaine~ decrease was observed. The changes were not different in healthy rats and those with prehepatic portal hypertension. In group o f 13 patients with liver cirrhosis / B u p to C s t a g e o f Child classification / with ~ortal hypertension acute intravenous adminxstratioa o f 5 m g o f verepamil led to mild to transient fall of blood pressure and did not change the heart rate. Wedged hepatic venous pressure decreased slowly during the 30 m i n u t e s ' p e r i o ~ a b o u t 30 p e r cent in average. Long-termed treatment of these patients with daily dose o f 1 6 0 m g v e r a p a m i l p e r os @accessed the blood pressure st rest, did not influence either the heart rate or mean wedged hepatic venous pressure. H o w e v e r , p o r tal hypertension level was reduced in 7 f r o m Ii cirrhotics, mainly in those w i t h r e l a t i v e l y constant activity of disease. Ist Department of Medicine, F a c u l t y H o s p i t a l , Charles University, C S - 5 0 0 36 H r e d e c K r ~ l o v 4 , CSSR

PP 16.43

PP 16.45

Withdrawn

EFFECTS OF INTRAVENOUS ADMINISTRATION OF NICORANDIL, A NEW A N T I A N G I N A L DRUG, ON SYSTEMIC AND C O R O N A R Y HEMODYNAMICS IN PATIENTS WITH ANGINA PECTORIS S. KARAKAWA~ M. YAMAGISHI~ J. TAMAI~ H. Takagi, H.OGAWA, A. KAWAGUCHI, F. OHMORI, S. NAGATA and K. MIYATAKE Intravenous infusion of nicorandil, [N-(2-hydroxyethyl)nicotinamide nitrate], effectively relieves both effort and rest angina. To examine the possible effects of nicorandil on systemic and coronary hemodynamies, nicorandil was intravenously infused in i0 patients who showed significant organic stenosis (>50%) in the proximal left coronary artery. Aortic pressure (AP, mmHg), pulmonary artery end-diastolic pressure (PADP, mmHg), coronary blood flow (CBF, ml/min, thermodilution method) and cardiac output (CO, I/min) were measured before and after (i, 5, 10, 15 min) nicorandil injection (0.08 mg/kg for 2 min). Coronary vascular resistance (CVR, mmHg. min/ml) and systemic vascular resistance (SVR, mmHg. min/l) Were calculated by dividing mean AP by CBF and CO, respectively. The plasma levels of nicorandil (ng/ml) was also determined at each point. Results are: meaniS.D. *p
A 341

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PP 16.48

IMPAIRED HEMODYN#MICFUNCTIONAFFECTSTHE PHARMACOKINETICSOF MONONITRATES IN PATIENTSWITH ACUTEMYOCARDIALIWARCTION A, MeiSner, S. Petersenn,H. T. Heidsnann, U. Osterka,p, R. Simon, H.M. Schulte I. Medizinische k'linik , Universit~t Kiel~ FRGermany

RAPID TACHYPHYLAXIS TO GLYCERYL TRINITRATE IN THE R A T WHICH IS PREVENTED BY N - A C E T Y L C Y S T E I N E C. M. Newman~ J. B. Warren, A. R. Boobis, G . ~ . T a y l o r and D. S. Davies Tolerance to the therapeutic effects of organic, b u t not inorganic, nitrovasodilators occurs when they are administered continuously for more than 12 hours. In previous animal models of nitrate tolerance in vivo it was necessary to administer large doses of nitrates over several days. We have now developed a model of tolerance to the organic nitrovasodilator, glyceryl tritiitrate (GTN), requiring treatment for only 1 hour. Male Sprague-Dawley rats (200-450 g) were anaesthetised with sodium pentobarbltone and the trachea cannulated. Mean arterial pressure (MAP) was measured directly through a cannula in the right common carotid artery. Drugs were administered i.v. through a second cannula in the right jugular vein. Sodium nitroprusside (NP), an inorganic nitrovasodilator, (4 /~g/kg) a n d GTN (10 #g/kg) were administered as bolus doses in 0.9% saline, before and again five minutes after infusion of 0.9% saline (n=4), GTN (40 #g/kg/min) (n=8) or NP (20 /~g/kg/min) (n=8) for 1 h (total volume 10 ml/kg). An additional group of G T N - i n f u s e d rats (n=8) received N-acetylcysteine (NAC), 200 m g / k g i.p. with the anaesthetic, 200 m g / k g as an i.v. bolus and 200 m g / k g infused in parallel with the GTN, Basal MAP was the same in all groups (pooled mean 114 -+ 3.3 mm Hg). Infusion of 0.9% saline had no effect on MAP. Infusion of GTN alone or with NAC reduced MAP, to a similar maximum extent (38.0 • 3.3% vs 39.6 -+ 2.7%, respectively). Infusion of NP produced a significantly greater maximum fall in MAP (51.7 _+ 3.6%, p<0.01 by ANOVA). The percentage fall in MAP following a bolus dose of GTN was compared with that induced by NP (GTN/NP ratio). There was no significant effect (by ANOVA) of infusion of 0.9% saline (GTN/NP pre-infusion: 1.00 + 0.09, post-infusion: 0.97 • 0.09) or of NP (GTN/NP pre-infusion: 0.94 _+ 0.04, post-infuslon: 1.06 -+ 0.07). In contrast, following infusion of G T N for 1 h the effect of a bolus dose of G T N on MAP was markedly reduced (GTN/NP pre-infusion: 0.88 • 0.05, post-infusion: 0.33 _+0.04, p<0.001 by ANOVA). This tachyphylaxis to GTN was prevented by treatment of the rats with NAC (total dose 600 mg/kg) (GTN/NP pre-infusion: 0.90 -+ 0.03, post-infusion: 0.82 • 0.07). Tachyphylaxis to the effects of GTN in the rat may be induced with a single 1-hour infusion. Prevention of this tachyphylaxis by NAC, which may also reverse nitrate tolerance in man, suggests that the mechanisms involved are similar. The model described here should prove of value in the elucidation o f the mechanism of this phenomenon. Department of Clinical Pharmacology, Royal Postgraduate Medical School, Ducane Road, London WI2 0NN, U.K.

Oral a~inistration of isosorbide-5-mononitrate (ISHI) recently gained increased i,~ortance in the therapy of coronary heart disease. As compared to other nitro compoundsapplication of ISN~ offers high bioavailability and small interindividual variations in plasma levels. In patients with acute myocardial infarction different degrees of heart failure may occur as a result of i~aired contractile function. The aim of this study was to investigate ISHq pharmacokinetics in various hen~dyna~ c situations after oral a~inistration. In 17 patients acknitted with acute myocardial infarction the central venous pressure (CVP) was measured before initiation of therapy as a parameter of global myocardial function. In group 1,9 patients with normal (~5 cm H20) CVP (2.7 +- 0.58 cm H20; "~'+ SEM) were included. Group II consisted of 8 patients with elevated (>5 cm H~) CVP (10.4 -+ 1.09 cm H20). After oral a~inistration of 20 ~ ISKl~ blood was dravm for measurement of nitrate levels by gaschromatographyfor 8 h. Results are shown in table I. Group I Group i i (CVP~5 cm H~O) (CVP>5 ~ H20) Cp 663 + 38.1 p~O.OO2 475 +- 31.7 ng/ml tp 33 + ,5.8 p
PP 16.47

PP 16.49

TISSUE DISTRIBUTION OF GLYCERYL TRINITRATE AND THE EFFECT ON cGMP LEVELS AFTER TOLERANCE DEVELOPMENT IN RAT. K. Torf$&rd~ $. Ahlner, K. L. Axelsson, B. Norlander and ~. Eertler Glyceryl trinitrate (GTN) h a s b e e n used as an antianginal agent for more than a century. The therapeutic effect of GTN, the vascular smooth muscle relaxation, is mediated by an increased intraeellular level of cyclic guanosine3',5'-monophosphate (cGNP). In the present study, tolerance was induced by treating male rats with GTN (50 mg/kg s.c.), 3 times daily for 3 consecutive days. Control animals were treated with ethanol (the solvent for GTN) according to the same schedule. A group of non-tolerant rats were given a single dose of GTN (50 mg/kg s.c.), and controls were given a single dose of ethanol. Rats were sacrificed 8 and 24 h after the last dose, and the eGMP level was measured in brain. The concentrations of GTN were measured in plasma, brain, heart, aortic tissue and adipose tissue by a gas chromatographic method. The results show no significant effect on the cGMP level 8 and 24 h after a single dose of GTN. Tolerant rats showed unchanged cGMP levels 8 h after the last dose, whereas a significant decrease from a basal value of 25.0• pmol/g w.w. to 10.8• pmol/g w.w. (n=5) was seen at 24 h. By contrast, the cGMP level in brain was significantly increased by about 40% 2 h after a single dose of GTN. The highest concentration of GTN was found in the adipose tissue (at 8 h 3209• ng/g w.w. and at 24 h 1069• ng/g w.w. for tolerant, at 8 h 1177• ng/g w.w. and at 24 h 206• ng/g w.w. for single dose). The concentration in brain tissue was 284• ng/g w.w. (8 h), 132• ng/g w.w. (24 h) and 67• ng/g w.w. (8 h), 17• ng/g w.w. (24 h) for tolerant and single dose, respectively. Generally the concentrations are higher in tolerant treated rats, both at 8 and 24 h. Connlusions: Tolerance development seems to induce changes in the cGMP-system in brain, and simple 2-point kinetic calculation indicates a slower elimination of GTN from the tissues studied. Departments of Pharmacology and Clinical Pharmacology, Link~ping Universityl S-581 85 Link~ping, Sweden

THE ACUTE EFFECT OF FLOSEQUINAN IN P A T I E N T S WITH SEVERE HEART FAILURE WHO ARE CANDIDATES FOR CARDIAC TRANSPLANTATION Schneeweiss

A.,

Marmor

A.,

Erdmann

E.

We studied the acute hemodynamic e f f e c t of the new vasodilator flosequinan in 9 p a t i e n t s with severe class 4 chronic heart failure, evaluated for cardiac transplantation. All patients were o n h i g h d o s e s of d i u r e t i c s a n d positive inotropic drugs. Four of them received also nitrates. After baseline hemodynamic measurements a single d o s e of flosequinan, I00 mg orally, was added to the conventional therapy and hemodynamic measurements were repeated for 2 hours. No new drugs were given during this period and no changes in t h e i n f u s i o n r a t e s of t h e d r u g already given were made. within one hour hemodynamic improvement, including decreases in pulmonary capillary wedge pressure, pulmonary arterial pressure and systemic vascular resistance and an increase in c a r d i a c o u t p u t w a s o b s e r v e d . It w a s s u s t a i n e d at 2 h o u r s . No symptomatic hypotension nor any adverse effects h a v e b e e n o b s e r v e d . In conclusion, the new vasodilator flosequinan can produce acute hemodynamic improvement when added to conventional therapy in patients with severe heart failure, candidates for cardiac transplantation. Cardiology Department, Rebecca Sieff Medical Center, 13100 Safed, Israel, and Medizinische Klinik I, Klinikum Grosshadern, Postfach 7 0 1 2 6 0 , D - 8 0 0 0 M u n c h e n 70