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The cytochrome P450 2D6 (CYP2D6) is involved in the metabolism of most antidepressants. Comedication with a potent CYP2D6 inhibitor can convert patients with extensive metabolizer (EM) or ultra-rapid metabolizer (UM) genotypes into poor metabolizer (PM) phenotypes. Since comedication is frequent in depressed patients treated with antidepressants, we investigated the effect of the CYP2D6 composite phenotype on antidepressant efficacy, taking into account both the CYP2D6 genotype and comedication with CYP2D6 inhibitors. 87 Caucasian in patients with a major depressive episode were prospectively treated with flexible doses of antidepressant monotherapy as well as comedications and genotyped for the major CYP2D6 alleles (CYP2D6*3 rs35742686, *4 rs3892097, *5 del, *6 rs5030655, and *2xN). They were classified for CYP2D6 composite phenotype and assessed for antidepressant response after 4 weeks. In terms of genotypes (g), 6 subjects were UMg, 6 PMg, and 75 EMg. Ten patients were coprescribed a CYP2D6 inhibitor, resulting in the following composite phenotypes (cp): 5 UMcp, 16 PMcp, and 66 EMcp. Whereas none of the CYP2D6 genotypes were significantly associated with antidepressant response, UMcp had a lower antidepressant response than PMcp or EMcp (respectively: 39.0 ± 17.9, 50.0 ± 26.0, and 61.6 ± 23.4, p = 0.02). Despite small sample size, this study suggests that a CYP2D6 composite phenotype, taking into account both genotype and comedications with CYP2D6 inhibitors, could predict CYP2D6 substrate antidepressants response. Thus, to optimize antidepressant response, CYP2D6 genotype could be performed and comedications with CYP2D6 inhibitors should be avoided, when prescribing CYP2D6 substrate antidepressants.

Data required to asses the risk of a new drug regarding the normal course of pregnancy as well as embryo, fetal and neonate development, are often missing when a new product is launched. In such a situation, a risk management plan is to be developed by the industrial and validated by regulatory authorities. This risk management plan is to take into account the data benefits on the drug and its potential therapeutic use by women as being of childbearing age. The obtaining of post licence human data is to be built on many players, both private and public, involved in the data collection and evaluation. The setting up of such a network would allow them to join together and optimize their action by standardizing the data collected and their follow up. This should help to generate or rapidly respond to an alert, to conduct collaborative pharmacovigilance pharmacology studies.

Evaluate the impact of educational intervention in decreasing ADEs in elderly patients in a hospital setting.Randomised prospective study.The study was performed in France in the Paris area, in 16 rehabilitation geriatric centres of APHP (Assistance Publique - Hôpitaux de Paris). Patient capacity per centre varied from 15 to 57 with a total of 526.All the patientsor = 65 years hospitalized during the 4 week study period were included.During a first 2 week phase without intervention ADE's were recorded in all centres. Then units were then randomised for an educational intervention or not. The educational phase lasted 1 week, without ADE tracking. Then, both types of units (I+ and I-) recorded ADEs for 2 weeks. Possible drug-related incidents were detected using a standardized check list (nurses) and a weekly review of all charts by investigators. Possible drug-related incidents were analysed by a group of reviewers selected from the authors to classify them as ADE or not.576 patients (mean age: 83.6 +/- 7.9 years) were consecutively included. The mean number of drugs at inclusion was 9.4 +/- 4.24 drugs per patient. 223 out of 755 events were considered "probable" ADEs (29.5%). Among the 223 ADEs, 62 (28%) could have been prevented. The main outcome of this trial was the change in the proportion of ADEs in elderly patients in the intervention-units, compared to the control group. The main errors were: to high a dose (26%), double therapy (21%), under dose (13%), inappropriate drug (13%), drug-drug interaction (6%), previous same adverse drug reaction (3%) and miscellaneous (11.18%). After a specific educational intervention program, there were fewer ADEs in the intervention group (n = 38, 22%) than in the control group (n = 63, 36%; p = 0.004).Educational programs could help reduce the prevalence of ADEs by 14% and encourage physicians to change outdated prescription habits.

Lupus anticoagulant was present in this case of paraneoplastic scleroderma revealed by hemolytic-uremic syndrome, suggesting that the autoantibody played a significant role in the sequence of events leading to anuria. Reviewing the literature we found several observations of paraneoplastic scleroderma, and in other series cases of scleroderma-linked (and in rare instances cancer-linked) antiphospholipid autoantibodies. Search for antiphospholipid antibodies should be considered in patients with systemic scleroderma as well as in patients with metastatic cancer. Presence of such procoagulant autoantibodies might predict future complications and should influence treatment strategy.

Molecular pharmacogenetic units have recently been established in several hospital laboratories in France. The clinical impact of these units is still limited and numerous problems of organizational, ethical, legal, technical, social and economical nature remain to be resolved. However, an increasing number of these units, a rise in their activities and an enlargement of their scope of application are foreseeable in the future. Ultimately, these units would significantly contribute to limit the public health problem caused by interindividual variabilities in drug effects. In view of these prospects, it seems essential that such hospital activity should be quickly recognised by the authorities and the various health sectors in France. It is also essential that the problems that arise from such pharmacogenetic activities should be considered by the authorities and would profit from the organization of a national network and from financial guarantees.

Maternal and fetal risk is often high during pregnancy in sickle cell disease. Our objective was to evaluate the benefits of a transfusion program adapted to each pregnant patient, either by red cell transfusion or by automated red cell exchange, in sickle cell patients with a history of serious obstetrical and/or sickling complications.We managed 18 pregnancies in 14 patients (12 SS, 1 SC, 1 S/b-thalassemia), seven of whom had a history of one or more pregnancies, with severe maternofetal complications in nine out of 10 cases. The other seven patients were pregnant for the first time and were in care because of a history of severe sickling complications. The aim was to achieve a proportion of abnormal hemoglobin (hemoglobin S or S+C) below 50% and a hemoglobin level between 9 and 11 g/dL. The choice between transfusion and red cell exchange was made in the light of the hemoglobin level. Red cell exchange was done using a Fresenius Com. Tec blood cell separator. Patients had red cell exchange in 10 cases, and transfusions in five cases. In three cases, patients had successive transfusions and red cell exchange.No serious maternal complication was observed. No fetal or perinatal death occurred. In one case, delivery was induced at 36 weeks of gestation because of fetal distress and hypotrophy.Our study suggests that women with severe sickle cell disease, even if they have a serious obstetrical history, can carry their pregnancy to term, without major obstetric complications, through a combination of early management by a multidisciplinary team and a suitable policy of prophylactic transfusion or automated red cell exchange.

Single nucleotide polymorphisms (SNPs) can significantly affect human phenotypes. Detection of allelic variant carriers has become a major goal for clinical pharmacologists in order to study phenotype-genotype relationships. However, there is a crucial need for rapid, and validated pharmacogenetic tests. The aim of the study was to validate a new fluorescence PCR strategy for cytochrome P450 2C9 (CYP2C9) and multidrug resistance gene (MDR1) genotyping. Results of CYP2C9 and MDR1 genotypes determined with reference techniques were compared to those obtained by allelic discrimination assays employing fluorescent TaqMan probes. Sixteen subjects carrying CYP2C9*2 and CYP2C9*3 allelic variants (heterozygous and homozygous) previously identified by sequencing and 55 subjects previously genotyped for MDR1 exon 26 (C3435T) SNP by conventional PCR-RFLP were genotyped with fluorescent PCR. Fluorescent PCR gave 100 % accuracy with the results obtained with reference genotyping strategies for each of the 3 SNPs. Genotyping results with fluorescent PCR repeated on three consecutive occasions remained constant over time for each of the 3 SNPs. Allelic discrimination assays based on fluorescent PCR gave entire satisfaction for CYP2C9 and MDR1 genotyping. This reliable genotyping strategy can be easily used in clinical practice and should be further developed for additional SNPs identification.

To assess the age-associated changes over time of plasma paraxanthine/caffeine (PAX/CAF) ratios used as a probe for CYP1A2 activity.Intraindividual and interindividual variabilities in PAX/CAF ratio were compared by phenotyping with caffeine, 16 young and 16 elderly healthy subjects on five occasions.PAX/CAF ratio variability was comparable regardless of age (intraindividual CV: 17.6 +/- 6% and 16.2 +/- 5.9%, interindividual CV: 48.1 +/- 2.9% and 42.7 +/- 3.6% in young and elderly, respectively). The PAX/CAF ratio was lower in elderly than in young subjects (95% CI for the difference: 0.004, 0.32) but the difference was not significant in nonsmokers compared separately.The variability over time of the PAX/CAF ratio is not influenced by age.

Grapefruit juice is responsible for drug interactions mediated by intestinal cytochrome P4503A4 inhibition and possibly P-glycoprotein inhibition in enterocytes. Our main objective was to determine whether grapefruit juice alters the bioavailability of digoxin, a P-glycoprotein substrate. The secondary objective was to determine whether the magnitude of the pharmacokinetic interaction was influenced by P-glycoprotein genetic polymorphism.Twelve healthy volunteers participated in this open randomized crossover study comparing the effect of grapefruit juice consumption (versus water) on the pharmacokinetics of a single oral dose of digoxin (0.5 mg). The P-glycoprotein genotype was determined according to MDR1 genetic polymorphism in exon 26 (C3435T).Grapefruit juice had no significant effect on the maximum plasma drug concentration (C(max)) of digoxin or the area under the plasma concentration-time curve (AUC) from time zero to 48 hours. However, there was a 9% increase in the digoxin AUC from time zero to 4 hours and from time zero to 24 hours (P =.01) during grapefruit juice administration. The digoxin renal clearance remained unchanged during both periods. No relationship between MDR1 C3435T genotype and early digoxin pharmacokinetic changes could be detected.The modest changes in digoxin pharmacokinetics observed during grapefruit juice ingestion do not support an important P-glycoprotein inhibition. Under our experimental conditions, grapefruit juice-mediated P-glycoprotein inhibition does not appear to play a relevant role in drug interactions, at least when assessed by use of digoxin disposition kinetics.

Liver drug metabolism is a major source of drug interactions. Three major human in vitro models are employed to detect drug interactions in the preclinical phases of drug development: recombinant enzymes, human liver microsomes and primary human hepatocyte cell cultures. Results obtained from these models may vary during the different phases of drug development. Identification of the metabolic pathways, enzymes involved in drug metabolism (mainly cytochrome P450s), enzyme induction or inhibition allow us to detect the major pharmacokinetic drug interactions which can occur in man and to identify specific populations at risk for such interactions. In vitro models are essential to decide if and which future drug interaction studies should be performed in man. However, the clinical relevance of the potential pharmacokinetic drug interactions detected by these in vitro models remains to be determined and confirmed by human studies.

To determine the viability and differentiation of human hepatocytes immunoprotected by encapsulation and transplanted in rats without immunosuppression.Freshly isolated human hepatocytes were encapsulated in hollow fibers and transplanted in the peritoneal cavity of immunocompetent rats. The fibers were explanted for analysis at D3, D7 and D14 following transplantation. Morphological features under light and electron microscopy and gene expression were compared to those of non-transplanted encapsulated hepatocytes (D0). Human cytochrome P450 3A and albumin mRNAs were quantified by Northern blot. Cytochrome P450 3A proteins were detected by Western blot and cytochrome P450 3A enzyme activity was assessed by measuring the formation of 6beta-hydroxytestosterone by high performance liquid chromatography.Transplanted hepatocytes were more than 60 % viable and exhibited morphological criteria of hepatocytic differentiation up to D7. Albumin and cytochrome P450 3A transcripts were also detected up to D14. At D3 and D7, albumin mRNA levels were of 30 %, compared to control D0 hepatocytes, while cytochrome P450 3A5 and cytochrome P450 3A4 mRNA levels were 65 % and 0 %, respectively. Cytochrome P450 3A immunoreactivity was detected by Western blot up to D14 and 6beta-hydroxylase activity was 17 % at D3 compared to D0, supporting with disappearance of cytochrome P450 3A4 mRNA.Human hepatocytes remain viable for a short period, following encapsulation and intraperitoneal transplantation in rat. Other experimental conditions need to be tested to prevent or delay a decrease in hepatocyte specific gene expression.

Zopiclone is a widely prescribed, nonbenzodiazepine hypnotic that is extensively metabolized by the liver in humans. The aim of the present study was to identify the human cytochrome P-450 (CYP) isoforms involved in zopiclone metabolism in vitro. Zopiclone metabolism was studied with different human liver microsomes and a panel of heterologously expressed human CYPs (CYP1A2, 2C8, 2C9, 2C18, 2C19, 2D6, 2E1, and 3A4). In human liver microsomes, zopiclone was metabolized into N-desmethyl-zopiclone (ND-Z) and N-oxide-zopiclone (NO-Z) with the following K(m) and V(m) of 78 +/- 5 and 84 +/- 19 microM, 45 +/- 1 and 54 +/- 5 pmol/min/mg for ND-Z and NO-Z generation, respectively. Ketoconazole (CYP3A inhibitor) inhibited approximately 40% of the generation of both metabolites, sulfaphenazole (CYP2C inhibitor) inhibited the formation of ND-Z, whereas alpha-naphtoflavone (CYP1A), quinidine (CYP2D6), and chlorzoxazone (CYP2E1) did not affect zopiclone metabolism. The generation of ND-Z and NO-Z were highly correlated to testosterone 6beta-hydroxylation (CYP3A activity, r = 0.95 and 0.92, respectively; p =.0001), and ND-Z was highly correlated to CYP2C8 activity (paclitaxel 6alpha-hydroxylase; r = 0.76, p =.004). Recombinant CYP2C8 had the highest enzymatic activity toward zopiclone metabolism into both its metabolites, followed by CYP2C9 and 3A4. CYP3A4 is the major enzyme involved in zopiclone metabolism in vitro, and CYP2C8 contributes significantly to ND-Z formation.

Both the antimalarial prodrug proguanil and the gastric proton pump inhibitor omeprazole are substrates for cytochrome P450 (CYP)2C19 and CYP3A. However, the relative contribution of each enzyme to proguanil bioactivation to cycloguanil and to the metabolism of omeprazole, as well as their potential to interact, remains to be examined. The bioactivation of proguanil to its active metabolite cycloguanil was studied in vitro in human liver microsomes and in vivo in 12 healthy subjects, in the absence and in the presence of omeprazole. The formation of cycloguanil from proguanil exhibited biphasic kinetic behavior in four of six human livers, indicating that at least two enzymes are responsible for this metabolic step. Cycloguanil formation activity did not correlate with immunoreactive CYP3A4 content or with CYP3A4 activity, as measured by testosterone 6beta-hydroxylation, suggesting that CYP3A4 plays a limited role in cycloguanil formation. Furthermore, troleandomycin (10 microM) inhibited only 10 to 17% of cycloguanil formation at proguanil concentrations of 100 and 500 microM. At a proguanil concentration of 20 microM, omeprazole at 10 microM inhibited cycloguanil formation in vitro by 47 +/- 59%. These in vitro results were consistent with the results of our in vivo study in healthy subjects, which showed a 32 +/- 11% decrease in proguanil apparent oral clearance and a 65 +/- 8% decrease in proguanil partial metabolic clearance to cycloguanil in the presence of omeprazole (both P.001). We conclude that in vitro studies of proguanil metabolism and interactions are predictive of in vivo situations, that CYP2C19 is the main enzyme responsible for proguanil bioactivation to cycloguanil and that omeprazole inhibits this biotransformation in vitro and in vivo by inhibiting this enzyme.

Dithiolethiones are thought to act as potent chemoprotective agents against aflatoxin B1 (AFB1)-induced hepatocarcinogenesis in the rat by inducing glutathione S-transferases (GSTs). To determine whether these antioxidants can be similarly effective in human beings, we have investigated metabolism of AFB1, in primary human hepatocytes with or without pretreatment by oltipraz (OPZ), a synthetic derivative of the natural 1,2-dithiole-3-thione. Aflatoxin M1 (AFM1), glutathione conjugates of AFB1 oxides (AFBSGs), and unchanged AFB1 were quantitated in cultures derived from eight human liver donors. Parenchymal cells obtained from the three GST M1-positive livers metabolized AFB1 to AFM1 and to AFBSGs derived from the isomeric exo-and endo-8,9-oxides, whereas no AFBSGs were formed in the GST M1-null cells. Pretreatment of the cells with 3-methylcholanthrene or rifampicin, inducers of CYP1A2 and CYP3A4, respectively, caused a significant increase in AFB1 metabolism. Although OPZ induced GST A2, and to a lesser extent GST A1 and GST M1, it decreased formation of AFM1 and AFBSG, which involves CYP1A2 and CYP3A4. Inhibition by OPZ of AFB1 metabolism by reducing CYP1A2 and CYP3A4 was also demonstrated by decreased activity of their monooxygenase activities toward ethoxyresorufin and nifedipine, respectively. The significant inhibition by OPZ of human recombinant yeast CYP1A2 and CYP3A4 was also shown. These results demonstrate that AFBSG can be formed by GST M1-positive human hepatocytes only, and suggest that chemoprotection with OPZ is due to an inhibition of activation of AFB1, in addition to a GST-dependent inactivation of the carcinogenic exo-epoxide.

To determine whether long-term treatment with cilazapril (CIL) may improve pulse pressure (PP), arterial compliance and ankle-arm systolic index (AAI) in patients with lower-extremity arterial disease (LEAD). Indeed, in both systolic hypertension and LEAD, the increase in pulse pressure has been attributed to a reduced compliance.Thirteen patients (age: 65 +/- 5 yrs; AAI: 0.78 +/- 0.15; m +/- SD) were included in a double-blind randomized parallel study to compare the effects of a 6 month treatment with CIL (10 mg per day; n = 6) to those of placebo (PL; n = 7) Blood pressure, AAI and arterial compliance were determined at baseline (MO) and after 3 (M3) and 6 months (M6). Common carotid (CC) and common femoral (CF) artery compliances were noninvasively determined from pulsatile changes in arterial diameter (Wall Track System, Hoeks et al., 1990) and pressure (PP).Both groups were comparable at MO. Compared to PL, CIL significantly reduced PP (-22 +/- 4 vs -2 +/- 9 mmHg) and MAP (-16 +/- 11 vs -4 +/- 7 mmHg) and improved CC (+54 +/- 34 vs +5 +/- 21 mm2.mmHg-1.10(-3)) at M6. Weaker effects were observed at M3. No significant changes in AAI and CF compliance were observed.A direct effect of CIL on the large artery wall was suggested by 1) a greater reduction in PP than in MAP and 2) a disproportionately greater improvement in CC compliance compared with the reduction in distending pressure (MAP). These results indicate that long-term treatment with CIL may improve large artery function in patients with LEAD.

Between 1968 and 1991, 36 pregnancies were reported in 28 patients who had undergone kidney transplantation at the Necker hospital, Paris. Pregnancies with favourable graft outcome were compared with those accompanied by significant deterioration of graft function and requiring haemolysis. The risk factors for renal function deterioration during pregnancy in kidney-transplanted women were found to be an initial nephropathy induced or aggravated by a previous pregnancy, an alteration, even mild, of graft function, hypertension, even controlled by treatment, an HLA mismatch and several episodes of acute graft rejection soon after kidney transplantation.

Anuria complicated the malignant phase of hypertension in twelve patients (ten males and two females). Five were black; five had primary hypertension; one had HBs virus angiitis; the six remaining cases suffered from previously documented renal disease, including two with Berger's disease. Renal angiography showed interruption of renal blood flow as far as the main branches of the renal artery and/or a false impression of 'cortical necrosis' and of 'renal infarcts'. In contrast, renal biopsy did not show irreversible vascular damage. Thus, anuria was mainly functional and due to active renal vasoconstriction. This was confirmed by the subsequent course; diuresis resumed after 1 week to 24 months of dialysis. Repeat angiography in six cases showed recovery of renal circulation and disappearance of 'cortical infarcts', even when plasma renin activity remained elevated and hypertension was not controlled. In one case captopril induced a new reversible episode of anuria. These observations suggest that active vasoconstriction with prolonged anuria might be due to some vasoconstrictive substance other than angiotensin II.