[Retrospective of national pharmacovigilance surveys on drug-induced bullous, vesicular eruptions: methods and results ]. / Rétrospective d'enquêtes nationales de pharmacovigilance sur les toxidermies: méthodologies et résultats.

UNLABELLED: The academic interest for pharmacovigilance appears to be very low, because of the judged weakness of a "significant" relationship between drug utilisation and pathological events. We have tried to collect the relevant surveys of the French pharmacovigilance network on cutaneous toxic reactions to show the use of this work for current medical knowledge. This study was limited to the most relevant reports: 1--Cutaneous disorders induced by local reactions to ketoprofen, bufexamac, paracetamol (i.v.) 2--Cutaneous disorders observed in systemic hypersensitivity syndromes: allopurinol, chlormezanone, pristinamycine 3--Photosensitisation (toxicity), including: Individual characteristics of patients Nature of the observed syndromes Induction time and evolution of the disease Imputation and apparent incidence of the cases observed RESULTS: 1--Concerning "contact" dermitis, erythematous skin reactions are the most frequently observed. The causality link is proved in 272 patients of the cases. The mean age of the patients is 40-50 and the induction time from one to ten days. 2--In the hypersensitisation syndromes, severe skin reactions, combined with general reactions (fever), are the most frequently observed. The mean age is 50-60 and the number of serious cases is high (4.5%). 3--Severe burns with bullous skin reactions are observed in phototoxicity cases. The mean age of the patients is 50. Time induction is short (ten days), the cases are frequently serious, but evolution appears good. In conclusion, the synthesis of pharmacovigilance surveys shows the value of this epidemiological approach to drug-induced skin reactions. It is regrettable that the results of this work are not more widely distributed.

Acute cyclosporine A-induced nephrotoxicity: a rabbit model.

Chronic cyclosporine A (CsA) nephrotoxicity has been widely assessed but only few studies have described acute nephrotoxicity. As CsA is now used for short periods, we developed an experimental model of acute CsA-induced nephrotoxicity. Renal clearances of inulin and para-aminohippurate were assessed in 35 New Zealand rabbits. Group 1: control, no treatment; group 2: CsA 25 mg/kg per day in 0.5 ml/kg per day for 5 days; group 3: vehicle Cremophor-EL, 0.5 ml/kg per day for 5 days; group 4: follow-up, the same as group 2, then CsA discontinuation for 31 days. Compared with group 1, CsA significantly decreased glomerular filtration rate (GFR), renal blood flow (RBF), and diuresis, with a significant increase in renal vascular resistance (RVR). The proportional fall in GFR (-32.3%) and RBF (-33.1%) suggests both pre- and postglomerular vasoconstriction. Discontinuation of CsA in group 4 led to normalization of RVR with improvement of other renal function parameters. Compared with group 1, Cremophor-EL induced no significant changes but an increased RBF. Microvacuolization of proximal tubule epithelial cells was the sole histological abnormality observed only in group 2. The overall results suggest that CsA induced a vasomotor acute renal failure which was not due to Cremophor-EL. This effect was partly reversible after discontinuation of treatment.

6-Mercaptopurine pharmacokinetics after use of azathioprine in renal transplant recipients with intermediate or high thiopurine methyl transferase activity phenotype.

Prevention of allograft transplant rejection by the immunosuppressive 6-thiopurine drug azathioprine is limited by haematological toxicity (leucopenia or agranulocytosis). This toxicity is particularly apparent in subjects with low thiopurine methyltransferase activity (TPMTase) phenotype (1% in the Caucasian population). The thiopurine derivative 6-mercaptopurine is the active metabolite of azathioprine, and it would be of interest to measure, after validation of plasma measurements, the mean values of the pharmacokinetic parameters in transplant patients with high or intermediate TPMTase phenotypes (85 and 14% of the Caucasian population, respectively). We measured erythrocyte TPMTase activity in 103 kidney transplant recipients of high or intermediate phenotype and calculated, after a test dose of azathioprine, the mean values of the pharmacokinetic parameters for 6-mercaptopurine. We also compared these values with the same parameters from one subject with low TPMTase activity phenotype. The mean observed area under the plasma concentration-time curve (AUC) was 190+/-140 ng mL(-1) h and the elimination rate constant (Kel) was 1.92+/-1. The pharmacokinetic parameters (AUC, Kel, t1/2el (the elimination half-life)) of 6-mercaptopurine in transplant patients are normally distributed and suitable for acceptance as a gold standard value for this population of Caucasian transplant patients. It seems useful to calculate these parameters, representative of the systemic exposure of individual patients to the drug, before prescribing these subjects azathioprine immunosuppressive treatment. In subjects with low TPMTase phenotype these pharmacokinetic measurements could also be an index of dose reduction.

Characterization of the in vitro glucuronidation of flurbiprofen enantiomers.

To investigate the glucuronidation of the R- and S-enantiomers of the nonsteroidal antiinflammatory drug, flurbiprofen, by liver microsomes of several mammals, including humans, a new and reliable HPLC method for the separation and quantification of the corresponding diastereoisomeric glucuronides has been developed. Interspecies comparison revealed that the glucuronidation of flurbiprofen was highly efficient with liver microsomes of humans, monkeys, rats, and guinea pigs (in decreasing ranking order). Gunn rats, which present a genetic defect in the bilirubin UDP-glucuronosyltransferase (UGT) isoforms, were still able to glucuronidate the drug. The R-enantiomer was glucuronidated faster than the S-form by liver microsomes of rats and humans. Although the KM of glucuronidation of R- and S-enantiomers by rat liver UGT were in same order of magnitude (apparent KM 0.52 and 0.57 mM, respectively), the apparent Vmax's were significantly different (9.34 and 5.48 nmol/min.mg of protein). Regardless of the enantiomer considered, the glucuronidation of flurbiprofen was strongly increased up to 5-fold by treatment of rats with phenobarbital and, at a lower extent, by 3-methylcholanthrene. In contrast, the treatment of rats with ciprofibrate markedly decreased the activity. Glucuronidation of R-flurbiprofen was more enhanced by phenobarbital than that of the S-antipode. Each flurbiprofen enantiomer could weakly inhibit the glucuronidation of its antipode in a noncompetitive way. The apparent Ki was 0.51 mM with R-flurbiprofen as a substrate, and 0.37 mM with S-enantiomer. On the other hand, the rat liver UGT2B1 isoform, stably expressed in V79 cells, could glucuronidate flurbiprofen in an appreciable amount.(ABSTRACT TRUNCATED AT 250 WORDS)

[Secondary hyperparathyroidism in the elderly. Apropos of 200 assays of intact parathormone]. / L'hyperparathyroïdie secondaire du sujet âgé. A propos de 200 dosages de parathormone intacte.

OBJECTIVES: To evaluate the frequency of high levels of intact parathormone in an elderly population of hospitalized patients and to determine whether there are any correlations with different factors involved in phosphocalcium metabolism, nutritional status and renal function. METHODS: Intact parathormone was assayed in all patients admitted to a geriatric ward (n = 200). Other laboratory tests included serum phosphorus, calcium, total albumin, prealbumin, ionized calcium, creatinine with calculation of the clearance and in 50 patients radioimmunoassay for 25 hydroxyvitamin D. RESULTS: Intact parathormone was abnormally high (> 65 pg/ml) in 40 patients. Mean levels increased significantly with age and reached 70.5 pg/ml in patients 90 years of age and over. No correlation was found between intact parathormone and total serum calcium, corrected serum calcium, albumin or prealbumin. Inversely there was a significant correlation with serum phosphorus and creatinine and creatinine clearance. Serum levels of 25 hydroxyvitamin D were abnormally low in 82% of the patients. There was a constant and significant decrease in intact parathormone level 15 days after calcium and calcifediol substitution therapy in 13 patients. CONCLUSION: The frequency of hyperparathyroidism increases with age to affect nearly 1 out of 2 subjects over 90. It would be useful to determine a threshold level for elderly subjects with a major risk of bone fracture.

[Secondary hyperparathyroidism in hospitalized aged patients: apropos of 200 assays of intact parathyroid hormone]. / Hyperparathyroïdie secondaire chez le sujet âgé hospitalisé: à propos de 200 dosages de parathormone intacte.

Plasma intact parathyroid hormone (PTH) determinations were performed in 200 elderly patients admitted in a geriatric care unit. Abnormally high levels of PTH were observed in 40 subjects. There was a significant correlation between plasma ionized calcium determinations or creatinine clearance and PTH levels. Subjects with high PTH levels exhibited constantly reduced levels of 25 OH-D3. A calcium and vitamin D supplement, performed in 13 patients, was constantly followed by a decrease of the PTH level.

Comparative pharmacokinetics of tetrahydropyranyl-doxorubicin and doxorubicin in rat isolated lung.

Rat isolated perfused lungs (Sprague-Dawley rats, n = 20) were studied to compare the pulmonary uptake of a new anthracycline, tetrahydropyranyl-doxorubicin (THP-DXR) with that of doxorubicin (DXR). Lung perfusions were initiated with a constituted medium containing either drug at concentrations of 1, 10 or 100 microM. Lungs were perfused by recirculation for 60 min. Thirteen perfusate samples were collected over 60 min and subjected to HPLC for assay. The perfusate concentration of THP-DXR decreased to 24 +/- 5% of the initial concentration and to 8 +/- 2%, 20 and 60 min after the beginning of the infusion, respectively. Corresponding values for DXR were 77 +/- 16 and 52 +/- 15%, respectively (P less than 0.05). During the THP-DXR perfusion, the area under the perfusate concentration vs time curve (AUC) was decreased to one-third and the clearance was increased 3-fold (P less than 0.05). The pulmonary concentration of THP-DXR reached 0.032 +/- 0.01 mumol g-1 60 min after the beginning of a perfusion of 1 microM of the drug. This concentration increased to 0.379 +/- 0.11 mumol g-1 when the initial dose concentration was 10 microM. Corresponding lung concentrations for DXR were 0.013 +/- 0.001 and 0.150 +/- 0.04 mumol g-1, respectively (P less than 0.05). The perfusate concentration/initial concentration ratio decreased by the same amount whether a 1 or 10 microM initial concentration of either drug was used. An initial concentration of 100 microM of THP-DXR, unlike DXR, consistently induced oedema in the perfused lung. No metabolite of either drug was revealed during the course of our study.(ABSTRACT TRUNCATED AT 250 WORDS)

[Side effects of fibrates (except liver and muscle)]. / Effets indésirables des fibrates (hors foie et muscle).

If the iatrogenic acute muscular syndromes (rhabdomyolysis) and hepatic diseases following hypolipidemic drugs therapy are very well known, the other unwanted effects associated with fibrate therapy are not well established. It is the reason why we have selected, in the computerised data base of side effects from the French Network of "Centres de Pharmacovigilance" organisation, the pathological events associated with fibrate therapy during five years (1985 to 1989) (with exception for the acute muscular and hepatic diseases). The 277 side effects represent 67% of the side effects in which the product is regarded as "suspect" (S). These effects were observed in 132 men (mean age = 57 years) and 145 women (mean age = 61 years). The most frequently encountered products are: fénofibrate (Lipanthyl) for 30%; ciprofibrate (Lipanor); gemfibrozil (Lipur); bézafibrate (Befizal); each for about 10%. The mean doses used were the same that suggested in the french therapeutic dictionary ("Vidal"). The unwanted effects observed were: Skin reactions: 22.8% Blood disturbances (and hemorrhage): 9.8% Gl diseases (pancreatitis), Libido and psychic disturbances, nervous system disorders: about 6% each. All clotting disturbances (5.8%) are interactions with coumarin derivatives. The incidence of serious side effects was low and the recovery very good in 80.9% of cases: no death. In conclusion, the toxicity of fibrates (with exception for rhabdomyolysis and hepatic reaction) appears unimportant: the most frequently observed side effects are skin reactions and blood disturbances (interactions) and rarely nervous system, psychic or libido disturbances. The recovery is good, and the general toxicity of all products appear to be of the same order of magnitude.

Effects of simvastatin, a lipoprotein-lowering drug, on the hepatic enzymes involved in drug metabolism in the Wistar rat.

1. Simvastatin, a competitive inhibitor of 3-hydroxy-3-methyl glutaryl CoA reductase, lowers the plasma cholesterol level and has been approved for treatment of hyperlipoproteinaemia. 2. Simvastatin has been studied for its effects on hepatic microsomal drug metabolism in rat. No induction of 7-ethoxyresorufin-O-deethylase (EROD), ethoxycoumarin-O-deethylase (ECOD) and of UDP-glucuronosyltransferases were found, in vitro, after administration of 0.5, 1.5 and 10 mg/kg per day for 22 days. 3. Epoxide hydrolases (microsomal and cytosolic) were also unchanged after treatment with simvastatin. 4. No increase of the palmitoyl CoA oxidase activity or of mitochondrial glycerol phosphate dehydrogenase activity occurred. 5. Fatty acid distribution in rat liver microsomal phosphatidylcholines showed a significant decrease of C16:1 and a significant increase of C20:4 acids.

Cyclosporine determinations in heart and liver transplant recipients: comparison of HPLC and FPIA methods on whole blood and plasma.

One hundred and eighty five whole blood samples were analysed for cyclosporine levels by fluorescence polarization immunoassay (FPIA) and high performance liquid chromatography (HPLC). 123 came from 4 heart transplant recipients (mean age +/- SD: 47.50 +/- 20.56 years) and 62 from 4 liver transplant recipients (44.50 +/- 16.52 years). FPIA was done on plasma and whole blood in heart transplant recipients, on plasma in the liver recipients. HPLC was always done on whole blood. The results show a good correlation between FPIA on plasma (y) and HPLC (x) in liver recipients (n = 62, r = 0.935, y = 1.23x + 70 ng/ml), slightly worse between FPIA on plasma (y) and HPLC (x) in heart recipients (n = 64, r = 0.610, y = 0.78x + 189 ng/ml) and mediocre for FPIA on whole blood (y) and HPLC (x) in heart recipients (n = 123, r = 0.566, y = 1.35x + 594 ng/ml).

Nutritional factors of microsomal enzymatic induction: influence of lipidic components of the diet.

We compared the ability of two different diets containing 6 per cent of maize oil and 6 per cent of fish oil to modify: firstly the enzyme induction by phenobarbital and secondly the phenobarbital hydroxylation by the liver either in vivo or during in vitro perfusions. The presence of fish oil in the diet increased the cyt P 450 content and the bilirubin glucuronosyl transferase activity. The two induction effects promoted by the association of the phenobarbital treatment and the eating of the fish oil were not additive and it was found that the phenobarbital induction effect was decreased by the fish oil consumption. Phenobarbital and p-hydroxyphenobarbital kinetics were different in the two groups of animals. Phenobarbital was more slowly eluted in the fish oil fed than in the maize oil fed rats while p-hydroxyphenobarbital was more slowly eluted by the fish oil-fed rat livers.

[Course of blood creatinine during repeated injections of cisplatin. Influence of drug combinations]. / Evolution de la créatininémie lors d'injections répétées de cisplatine. Influence des associations médicamenteuses.

Cisplatin (CDDP) is known to induce nephrotoxicity. In this retrospective study, we have investigated the evolution of plasma creatinine in long term therapy with CDDP. We have studied case history, mode of administration of CDDP and associations with other chemotherapeutic agents or drugs which could potientiate CDDP renal damage (non steroidal anti-inflammatory agents, analgesics, antibiotics, antihypertensive agents, diuretics and contrast media). Mean creatinine concentration versus time rises significantly. This elevation is significantly higher in patients with hypertension, diabete, one functional kidney, or abdominoperineal irradiation. The association with other drugs has not proved a real influence on creatinine evolution.

Differential action of thyroid hormones and chemically related compounds on the activity of UDP-glucuronosyltransferases and cytochrome P-450 isozymes in rat liver.

The effect of thyroid hormones and chemically related compounds, on the activity of UDP-glucuronosyltransferases (EC 2.4.1.17) and cytochrome P-450-dependent monooxygenases in rat liver microsomes was investigated. The animals were thyroidectomized and treated with different doses of the drugs for 3 weeks. Opposite effects were observed depending on the isoenzyme of UDP-glucuronosyltransferase considered. While 3,3',5-triiodo-L-thyronine, 3,3',5-triiodothyroacetic acid, 3,3',5-triiodothyropropionic acid, isopropyldiiodothyronine and L- and D-thyroxine strongly increased 4-nitrophenol glucuronidation in a dose-dependent fashion, they decreased markedly bilirubin glucuronidation. However, the activity toward nopol, a monoterpenoid alcohol, was not significantly changed regardless of which compound or dose was used. Variation of UDP-glucuronosyltransferase observed with 4-nitrophenol and bilirubin was related to the thyromimetic effect of the drugs estimated from the increase in alpha-glycerophosphate dehydrogenase. Thyronine and 3,5-diiodo-L-tyrosine, which did not enhance this activity, also failed to affect glucuronidation. Variations in UDP-glucuronosyltransferase activity were more likely due to changes in protein expression rather than changes in enzyme latency, since lipid organization of the microsomal membrane, as estimated from the mean anisotropy of 1,6-diphenyl-1,3,5-hexatriene by fluorescence polarization was not significantly modified by the drug administration. Although some of the drugs could significantly decrease the triacylglycerol and cholesterol contents in plasma, all failed to affect lauric acid hydroxylation. The activities of catalase, palmitoyl-CoA dehydrogenase (CN- insensitive) and carnitine acetyltransferase in the fraction enriched in peroxisomes were also not significantly affected by treatment with the thyroid hormone LT3. In contrast, the activity of 7-ethoxycoumarine O-deethylase was increased by large doses of thyronine and by 3,3',5-triiodothyropropionic acid. The concentration of total cytochrome P-450 was decreased in a dose-dependent fashion by all the compounds used, except thyronine. Finally, significant correlations were observed between glucuronidation of bilirubin and 4-nitrophenol and the content in cytochrome P-450. This suggests a possible coordinate regulation of the two processes, which depends on the physicochemical characteristics of the thyroid hormones and related compounds.

Pharmacokinetics of amiodarone in the isolated rat lung.

In these studies we examined the kinetics of amiodarone (Am) uptake and efflux in/from the lung, and the influence of other amphiphilics on these processes. We used single-pass perfused isolated lungs from rats. Medium containing Am (30 microM + 1 microCi of [14C]Am) was perfused through the lung for 20 min (uptake), followed by 20 min of perfusion with drug-free medium (efflux). Lack of metabolism enabled us to follow Am by measuring the amount of radioactivity in perfusate and lung. Other concentrations of Am (3, 60 and 120 microM; n = 2-4 each) were also examined. Inhibited uptake and accelerated efflux of Am were attempted with the pneumophilic amphiphilics chlorimipramine, chlorphentermine, chlorpromazine, verapamil and with the main metabolite of Am: desethylamiodarone (60 and/or 240 microM; n = 3-4 lungs each). Lung extracted Am extensively during uptake. The amount of Am accumulated at 20 min (inflowing concentration: 30 microM) averaged 1307 +/- 109 (S.E.) nmol/g, corresponding to a tissue to medium ratio of 43.3 +/- 1.6. Spontaneous efflux of Am was incomplete. At 40 min, 862 +/- 105 nmol of Am remained bound per g of lung, suggesting sequestration of Am in a slowly effluxable pool in which calculations show that more than 50% of the drug will ultimately persist. Uptake and efflux rates obey biexponential kinetics, indicating storage into two pools. Uptake rate and the amount of Am accumulated in lung at 20 min increased in proportion to inflowing concentration up to 60 microM. At 120 microM the increase was less. Neither amphiphilic was capable of inhibiting Am uptake, whereas only chlorphentermine significantly accelerated Am efflux.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of creatinine and inulin clearances in multiple trauma.

Creatinine clearance (Ccr) is a good predictor of renal dysfunction. However, numerous analytical interferences have been observed with the classical measurement of creatinine by Jaffé's procedure. This prospective study was conducted to compare 4 methods for determining creatinine; and also endogenous creatinine clearance with inulin clearance (Cin) to estimate the glomerular filtration rate. The 4 different techniques for measuring creatinine were: 1) 2 techniques using Jaffé's colorimetric reaction: one with rapid and the other with slow kinetics: 2) 2 more selective methods: enzymatic procedure and high performance liquid chromatography (HPLC). Measurements were performed in 13 multiple trauma patients after stabilization and in 5 comatose patients (control group) over a 3-day period, with strict 24-h urine collection. On the second day, inulin clearance and para-aminohippuric acid clearance (Cpah) were measured. Measurement of creatinine by Jaffé's procedure yields significantly higher levels than those obtained by the other methods. Higher levels of both plasma and urinary creatinine were observed in the multiple trauma patients with all the methods used. There were no significant differences in Ccr, Cin, Cpah between the multiple trauma patients and the control patients. The best correlations between inulin clearance and creatinine clearance were observed for Jaffé's rapid kinetics (r = 0.90) in the control group and for the enzymatic procedure in the multiple trauma group (r = 0.55). Plasma creatinine is not a useful indicator in multiple trauma. The correlation between creatinine clearance and inulin clearance is not very strong in multiple trauma, indicating that the relative evolution (not the absolute values) of creatinine clearance is of interest.