AIMS:Nefopam is a nonmorphinic central analgesic, for which no recommendation exists concerning adaptation of regimen in aged patients with or without renal impairment. The objective was to describe the pharmacology of nefopam in aged patients to obtain guidelines for practical use.METHODS:Elderly patients (n = 48), 65-99 years old, with severe or moderate renal impairment or with normal renal function, were recruited. Nefopam (20 mg) was administered as a 30 min infusion postoperatively. Simultaneously, a 1 min intravenous infusion of iohexol was performed, in order to calculate the glomerular filtration rate. Blood samples were drawn to determine nefopam, desmethyl-nefopam and iohexol plasma concentrations. Nefopam and desmethyl-nefopam concentrations were analysed using a nonlinear mixed-effects modelling approach with Monolix version 4.1.3. The association between pharmacokinetic parameters and treatment response was assessed using logistic regression.RESULTS:A two-compartment open model was selected to describe the pharmacokinetics of nefopam. The typical population estimates (between-subject variability) for clearance, volume of distribution, intercompartmental clearance and peripheral volume were, respectively, 17.3 l h(-1) (53.2%), 114 l (121%), 80.7 l h(-1) (79%) and 208 l (63.6%). Morphine requirement was related to exposure of nefopam. Tachycardia and postoperative nausea and vomiting were best associated with maximal concentration and the rate of increase in nefopam plasma concentration.CONCLUSIONS:We identified the nefopam pharmacokinetic predictors for morphine requirement and side-effects, such as tachycardia and postoperative nausea and vomiting. In order to maintain morphine sparing and decrease side-effects following a single dose of nefopam (20 mg), simulations suggest an infusion time of >45 min in elderly patients with or without renal impairment.

Therapeutic drug monitoring (TDM) of antiretrovirals requires accurate and precise analysis of plasma drug concentrations. This work describes a simple, fast and sensitive UPLC-MS/MS method for determination of the commonly used protease inhibitors such as amprenavir, atazanavir, darunavir, indinavir, lopinavir, ritonavir, saquinavir and tipranavir, tenofovir a nucleoside reverse transcriptase inhibitor (NRTI), the non-NRTI such as efavirenz, nevirapine, etravirine, the CCR5 antagonist maraviroc as well as the more recent antiretrovirals, the integrase inhibitors such as raltegravir, elvitegravir and the new direct acting anti-HCV boceprevir. Adapted deuterated internal standard was added to plasma aliquots (100 μl) prior to protein precipitation with methanol and acetonitrile. This method employed ultra-performance liquid chromatography coupled to tandem mass spectrometry with electrospray ionization mode. All compounds eluted within 4.2-min run time. Calibration curves were validated, with correlation coefficients (r2) higher than 0.997, for analysis of therapeutic concentrations reported in the literature. Inter- and intra-assay variations were <15%. Evaluation of accuracy shows a deviation <15% from target concentration at each quality control level. No significant matrix effect was observed for any of the antiretroviral studied. This new validated method fulfills all criteria for TDM of 15 antiretrovirals and boceprevir drugs and was successfully applied in routine TDM of antiretrovirals.

Des analyses biochimiques post-mortem peuvent être utiles pour la recherche de la cause de la mort. L’acidocétose est une complication fréquente et parfois mortelle du diabète, avec d’éventuelles implications médicolégales.

A specific liquid chromatography-mass spectrometric (LC-MS) method using an ion trap spectrometer was developed for the quantitation of articaine in human plasma. Articaine and the internal standard (trazodone) were extracted in a single step with diethyl-ether from 0.5 mL of alkalinized plasma. The mobile phase consisted of acetonitrile with 0.1% formic acid (40:60, v/v). It was delivered at a flow rate of 0.3 mL/min. The effluent was monitored by MS in positive-ion mode. Ionisation was performed using an electrospray ion source operating at 200 degrees C. Articaine was identified and quantified in SIM mode at m/z 185. Calibration curves were linear over the concentration range of 78.1-5000 ng/mL with determination coefficients>0.996. This method was fast (total run-time<3 min), accurate (bias<16%), and reproducible (intra-assay and inter-assay precision<14%) with a quantitation limit of 78.1 ng/mL. The good specificity and sensitivity achieved by this method allowed the determination of articaine plasma levels in patients following a submucosal infiltration injection of articaine in the patients undergoing a third molar surgery.

Meprobamate is a carbamate, main active metabolite of carisoprodol [1], used as an anxiolytic agent and prescribed in Europe and the USA. Carisoprodol is a prescribed centrally active muscle relaxant analgesic. Carisoprodol is extensively converted to meprobamate. Meprobamate plasmatic levels exceed those of carisoprodol 2.5 h after oral administration of 700 mg of carisoprodol to healthy volunteers [2]. Meprobamate is involved in 7% of psychotropic poisonings [3]. Meprobamate has a barbiturate-like mode of action at the GABAA receptor and at high concentrations is able to cause chloride ion infuse. Well-known toxic effects of a meprobamate overdose include central nervous system (CNS) depression, weakness, clonus and hyperactive reflexes, tachycardia, hypotension and respiratory depression. Meprobamate produces CNS-depressing symptoms [4]. Meprobamate intoxications are often serious and sometimes fatal (5%), resulting from haemodynamic disturbance and circulatory collapse, secondary to severe acute cardiac failure [3]. The mechanism of cardiac toxicity is unknown. An overdose of meprobamate results in coma, generally estimated by the Glasgow Coma Scale (GCS). Only one study, including few patients (n= 21), has evaluated the relationship between meprobamate plasmatic concentrations and GCS [5]. Classically, a nonsevere coma appears with meprobamate concentration between 60 and 120 mg l−1 and deep coma >120 mg l−1. We have studied the relationship between GCS and meprobamate plasma concentration in meprobamate intoxication and evaluated the pertinence of determining the meprobamate plasma level. We have reviewed all toxicological analyses made from January 2002 to September 2007. All patients with a plasma concentration of meprobamate higher than normal (>20 mg l−1) have been included. Blood samples were collected when the patient was admitted to the Emergency Department of the University Hospital. Meprobamate plasma concentrations and GCS were analysed. Meprobamate plasma concentrations were determined by a simplified, rapid and accurate gas chromatographic method [6], using a Delsi Instrument Series 30 gas chromatograph equipped with a flame ionization detector and split-splitless injection. GCS was classified into three groups: as severe group A (GCS 3–8); moderate group B (GCS 9–12); and mild group C (GCS 13–15). Statistical analysis was conducted using an analysis of variance (anova) and the Kruskal–Wallis test, with a level of significance P= 0.05. The research was conducted in compliance with the requirements of our Institutional Review Board. A total of 59 cases were collected. Mean age was 43 years (range 16–69) with a male : female ratio of 0.6. The mean plasma meprobamate concentration was 99.9 ± 13 mg l−1 (therapeutic range 10–25 mg l−1) with a maximal concentration of 271 mg l−1. Mean GCS was 7.1 ± 0.95 (range 3–15). The GCS partition was group A, n= 42; group B, n= 9; and group C, n= 8. In 87% of cases (n= 51), meprobamate had been ingested with concomitant drugs, mainly benzodiazepines (n= 35) or alcohol (n= 17). In 25 cases, the drug involved was the associated meprobamate/aceprometazine, brand name Mepronizine® in France. Meprobamate was the only drug detected in eight cases. Combination with tricyclic antidepressants was found in three cases. Concomitant ingestion of benzodiazepine was equally distributed among the three groups. Fifty-eight patients recovered. One fatal outcome was observed in a 57-year-old woman with a plasma level of meprobamate of 147 mg l−1, associated with a lethal concentration of propranolol of 1260 µg l−1, (therapeutic range 50–150 µg l−1). A high concentration of meprobamate was associated with low GCS (P= 0.0194) (Table 1). For patients with GCS = 3, meprobamate was detected in three cases, with a plasma concentration from 37 to 177 mg l−1. At a high level of consciousness (GCS = 15) a patient presented a meprobamate plasma concentration of 95 mg l−1. In the fatal case, the cause of death could not be attributed to meprobamate alone. According to the American Association of Poison Control Centers, propranolol is responsible for 71% of fatal β-blocker ingestion [7]. In our study, some interindividual variations were observed. Genetics differences have been studied only with carisoprodol. The study about CYP2C19 genotype and the pharmacokinetics of carisoprodol [8] concluded that there are no significant differences with respect to normal and nonfunctional CYP2C19 alleles in acute impairing effects of a single dose of carisoprodol. Conscious patients, with high meprobamate concentrations, are probably addicted to this drug. GCS, as a surrogate marker of meprobamate toxicity, is inferior to direct objective serum measurement and meprobamate levels, despite a high correlation based upon patient sample. Meprobamate concentration determination remains essential for the diagnosis of poisoning and ensures appropriate care of patients (electrocardiogram, intensive care). In our hospital, when meprobamate intoxication is suspected, we systematically determine the dosage of plasma meprobamate. This attitude may explain the absence of fatal outcomes. None declared.

Abstract:  Thiodicarb is a nonsystemic carbamate insecticide whose acetylcholinesterase activity is related to its main methomyl degradation product. A 40‐year‐old woman was found dead in her car. Empty packages of medicines and an open bottle of Larvin® containing thiodicarb were found near her body. No signs of violence nor traumatic injuries were noticed upon autopsy, and police investigations strongly suggested a suicide. Systematic toxicological analysis performed on postmortem specimens revealed the presence of various sedatives, hypnotics, and antipsychotic drugs in blood, urine, and gastric content. Some of the compounds identified were determined at blood concentrations well above the known therapeutic concentrations: zolpidem (2.87 mg/L), bromazepam (2.39 mg/L), nordazepam (4.21 mg/L), and levopremazine (0.64 mg/L). Specific analysis of thiodicarb and of its methomyl metabolite was then performed on all fluids and tissues collected during autopsy by liquid chromatography ion trap tandem mass spectrometry (LC‐MS‐MS). The anticholinesterase capacity of blood, urine, and gastric content collected at autopsy was 83%, 82%, and 32%, respectively (normal value: 0%). The presence of thiodicarb in the bottle found near the body corroborates the hypothesis of an intake of that compound. Although thiodicarb was only detected in gastric content (24.3 mg/L), its methomyl metabolite was quantified in most postmortem tissues and fluids: gastric content (19.9 mg/L), peripheral blood (0.7 mg/L), urine (8.5 mg/L), bile (2.7 mg/L), liver (0.7 mg/kg), kidney (1.7 mg/kg), lung (1.5 mg/kg), brain (9.3 mg/kg), and heart (3.6 mg/kg).

Objectif : Décrire la distribution du méprobamate dans différents tissus et fluides biologiques collectés lors de l'autopsie concernant huit cas de décès pour lesquels le méprobamate a été identifié dans le sang périphérique. Méthodes : Les prélèvements autopsiques disponibles étaient le plus souvent le sang périphérique, le sang cardiaque, l'humeur vitrée, la bile, le foie, le rein, le poumon, le coeur et le cerveau. Les échantillons (fluides et homogénats tissulaires) étaient analysés par LC-MSn à trappe d'ions, après extraction liquide-liquide en présence de carisoprodol (étalon interne). Résultats : Les concentrations de méprobamate dans le sang périphérique variaient de 9 à 160 mg/L. Les coefficients de distribution post-mortem du méprobamate, exprimés par le rapport [concentration dans le tissu (mg/kg) ou fluide d'intérêt (mg/L)]/[concentration dans le sang périphérique (mg/L)], étaient de 0,97 pour le sang cardiaque (n=8), 0,83 pour l'humeur vitrée (n=6), 1,16 pour la bile (n=8), 2,63 pour le foie (n=6), 1,82 pour le rein (n=8), 1,81 pour le coeur (n=8), 1,83 pour le cerveau (n=8) et 1,74 pour le poumon (n=8). Les coefficients de variation associés à ces moyennes étaient tous inférieurs à 25 %, excepté pour le foie (31 %). Conclusion : Avec des coefficients de distribution moyens proches de 1, le méprobamate ne semble pas s'accumuler dans l'humeur vitrée et la bile. Dans les autres tissus, ces coefficients varient de 1,7 à 2,6, objectivant ainsi une distribution tissulaire modérée, en accord avec le volume apparent de distribution peu élevé du méprobamate (0,7 L/kg). En dépit du nombre limité de cas étudiés, la variabilité inter-individuelle relativement peu importante de la distribution tissulaire de méprobamate pourrait théoriquement suggérer l'utilisation des concentrations tissulaires post-mortem en vue d'une estimation des concentrations dans le sang périphérique, lorsque cette matrice n'est pas disponible à l'autopsie. Pour être confirmés, ces résultats nécessitent d'être complétés dans une plus large étude.

Le thiodicarbe est un insecticide liquide de la famille des carbamates anticholinestérasiques, dont l'activité est en partie liée à son principal produit de dégradation, le méthomyl. Une femme de 40 ans est retrouvée sans vie dans son véhicule au côté de plusieurs emballages de médicaments et d'un flacon ouvert de Larvin® (thiodicarbe). L'autopsie ne permet pas de déterminer l'origine de la mort, et laisse suspecter, du fait des circonstances, une origine toxique dans un but d'autolyse. Le contenu gastrique ainsi que les prélèvements sanguins et tissulaires effectués lors de l'examen post-mortem sont adressés au laboratoire pour analyses toxicologiques. Ces analyses ont permis d'identifier dans le sang, les urines et le contenu gastrique de la victime, plusieurs substances médicamenteuses, en particulier, le zolpidem, le bromazépam, le nordiazépam et la lévoprémazine dont les concentrations sanguines ont été retrouvées nettement supérieures aux valeurs connues pour être thérapeutiques. Les dosages spécifiques du thiodicarbe et du méthomyl ont été réalisés par CLHP-SM/SM à trappe d'ions dans l'ensemble des prélèvements autopsiques. Le pouvoir anticholinestérasique du sang, des urines et du contenu gastrique était respectivement de 83, 82 et 32% (normale : 0%). L'analyse du contenu de la bouteille découverte sur la scène, confirmait la nature du composé. Alors que le thiodicarbe n'a été mis en évidence que dans le contenu gastrique, son principal métabolite a été détecté dans la plupart des tissus et fluides autopsiques analysés. Ceci peut s'expliquer par l'instabilité du thiodicarbe dans un environnement acide, tel que l'estomac. Les concentrations de méthomyl mesurées dans la plupart des tissus et/ou fluides sont compatibles avec les concentrations mesurées dans des cas similaires, bien que ces dernières soient sujettes à une importante variabilité. La forte inhibition cholinestérasique est vraisemblablement à l'origine d'une paralysie respiratoire et de troubles hémodynamiques qui, conjugués à la toxicité des substances médicamenteuses également présentes en quantités importantes, ont conduit à une dépression respiratoire majeure fatale en l'absence de prise en charge thérapeutique rapide.

ASSESSMENT OF OCCUPATIONAL EXPOSURE TO CYTOTOXIC DRUGS WITH PLATINUM The past 20 years have been an explosion in the introduction of effective cytostatic drugs (C.D.) for treating malignant diseases. Not only has the number of agents increased, so has the frequency with which they are used (Pilger et al., 2000). Workers handling C.D., such as nurses, pharmacy technicians and pharmacists, involved in their preparation and administration, and workers employed in the synthesis and production of these products, may face health risks. Several C.D. have been shown to be mutagenic, teratogenic, and carcinogenic in experimental systems (De Meo et al., 1995). The effects of continuous low-level exposures to C.D. in working environments are still controversial. A study was conducted to investigate whether oncology nurses are occupationally contaminated by antineoplastic drugs by measuring their urinary concentration by inductively coupled plasma mass spectroscopy (ICP-MS). Platinum, included in a lot of C.D., is used as marker for drug handling. The exposed group consisted of nurses, pharmacy technicians, and pharmacists employed by hospitals of Champagne County in France and handling C.D. Each person was interviewed and a questionnaire was filled in. The questions covered a detailed occupational, medical, and family history. Thirty-three nurses, pharmacy technicians, and pharmacists of seven different departments participated in this study. During occupational activities, such as preparation and administration of these drugs, acute toxic effects had not been observed. An elevated level of urinary platinum was found in one nurse (0.15 μg/L or 0.63 μg/g creatinine) in comparison with the nonexposed control group. It seems that the elevation of urinary platinum in urine was related to occupational exposure to platinum-containing C.D. The same result was found in another study including 13 hospital pharmacists and pharmacy technicians (Ensllin et al., 1997). It can be concluded that the concentration of 0.15 μg/L found in only 1 sample (i.e., 3% of exposed workers) is above the background signal and is much higher than the upper concentrations found in subjects exposed to gold dental restorations. In fact, biological monitoring by ICP-MS using specific antineoplastic tracers assesses the exposure to the specific chemical substance under investigation. It seems to be sufficiently sensitive to detect people exposed to low levels of chemicals, and yields more information on potential health risk than information obtained by ambient monitoring. But the results of the study including 33 exposed subjects with 1 positive case imply that one should carry out research in this field with the same methodological aspects. Health care workers preparing C.D. must receive initial and annual training, and should be provided with laminar air-flow hoods and personal protective devices. In all cases, the employers should offer workers all necessary information to achieve a safe working situation.

Dans le cadre des différents thèmes de travail proposés aux membres de la commission de Toxicologie Clinique de la SFTA, une étude est réalisée sur l'identification et la quantification simultanée de 12 benzodiazépines dans le plasma. L'objectif est de tester la robustesse d'une technique d'extraction en l'imposant aux différents participants, les conditions chromatographiques de séparation et le mode de détection restant libres, fonctions de l'équipement de chaque laboratoire. L'étude a été réalisée sur une période de 2 mois et demi. Deux échantillons tests de plasmas surchargés avec 12 benzodiazépines à des concentrations thérapeutiques ou supra-thérapeutiques sont adressés à chaque centre d'investigation en vue de leur évaluation. La technique d'extraction utilise un mélange d'hexane / dichlorométhane en milieu tamponné (pH 9.2) et le loflazépate d'éthyle comme standard interne. Une méthode CLHP avec détecteur à barrette de diode est proposée à défaut par le laboratoire coordonnateur aux participants ne disposant pas de technique d'analyse. Sur les 11 participants, 10 utilisent une technique CLHP, un seul une technique CPG. Parmi les techniques CLHP, 2 d'entre elles associent un détecteur de masse, 7 un détecteur à barrette de diodes, 1 un détecteur UV. La technique CPG est associée à un détecteur de masse. L'analyse des résultats montre que la technique d'extraction proposée a été testée avec succès par 8/11 des participants : 4/11 laboratoires sans erreur et 4/11 laboratoires avec 1 ou 2 résultats exclus. Par contre, 3/11 laboratoires ont rencontré des difficultés majeures : un site par la survenue d'émulsions lors du traitement des échantillons tests (plasmas lyophilisés à reconstituer), un site par manque de temps et d'expérience, le troisième mettant en cause le choix du standard interne en technique CPG, le loflazépate d'éthyle n'ayant pas fait l'objet d'une étude préalable par cette technique.

La prescription de plus en plus fréquente du dextropropoxyphène (DP) et du tramadol, deux antalgiques opioïdes, a conduit les membres du groupe de travail "Toxicologie hospitalière" de la Société Française de Toxicologie Analytique (SFTA) à étudier leur toxicité clinique observée. L'étude a consisté en l'analyse des cas où l'une ou l'autre de ces molécules a été identifiée au décours d'un screening toxicologique réalisé durant l'année 2004 dans les laboratoires hospitaliers des membres de ce groupe. Pour chaque patient ont été recueillis les données démographiques, les concentrations plasmatiques en dextropropoxyphène, norpropoxyphène (NP) ou tramadol, la concentration plasmatique en paracétamol, les médicaments associés et les signes cliniques (digestifs, respiratoires, cardiaques et neurologiques). Aucune relation entre les concentrations plasmatiques de dextropropoxyphène et de paracétamol, ni entre celles de dextropropoxyphène ou de tramadol et la gravité clinique n'a été observée. Les concentrations plasmatiques observées en dextropropoxyphène sont faibles mais doivent attirer l'attention sur une éventuelle intoxication au paracétamol. Les concentrations plasmatiques en tramadol peuvent être élevées mais les intoxications sont dans l'ensemble peu sévères et les concentrations toxiques semblent très supérieures à la concentration de 1 mg/L.