Claire Gozalo

Validation of a fast method for quantitative analysis of elvitegravir, raltegravir, maraviroc, etravirine, tenofovir, boceprevir and 10 other antiretroviral agents in human plasma samples with a new UPLC-MS/MS technology.

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 (100μl) 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 (r(2)) 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.

Sulfonylurea Therapy Benefits Neurological and Psychomotor Functions in Patients With Neonatal Diabetes Owing to Potassium Channel Mutations

OBJECTIVE Neonatal diabetes secondary to mutations in potassium-channel subunits is a rare disease but constitutes a paradigm for personalized genetics-based medicine, as replacing the historical treatment with insulin injections with oral sulfonylurea (SU) therapy has been proven beneficial. SU receptors are widely expressed in the brain, and we therefore evaluated potential effects of SU on neurodevelopmental parameters, which are known to be unresponsive to insulin. RESEARCH DESIGN AND METHODS We conducted a prospective single-center study. Nineteen patients (15 boys aged 0.1–18.5 years) were switched from insulin to SU therapy. MRI was performed at baseline. Before and 6 or 12 months after the switch, patients underwent quantitative neurological and developmental assessments and electrophysiological nerve and muscle testing. RESULTS At baseline, hypotonia, deficiencies in gesture conception or realization, and attention disorders were common. SU improved HbA1c levels (median change −1.55% [range −3.8 to 0.1]; P < 0.0001), intelligence scores, hypotonia (in 12 of 15 patients), visual attention deficits (in 10 of 13 patients), gross and fine motor skills (in all patients younger than 4 years old), and gesture conception and realization (in 5 of 8 older patients). Electrophysiological muscle and nerve tests were normal. Cerebral MRI at baseline showed lesions in 12 patients, suggesting that the impairments were central in origin. CONCLUSIONS SU therapy in neonatal diabetes secondary to mutations in potassium-channel subunits produces measurable improvements in neuropsychomotor impairments, which are greater in younger patients. An early genetic diagnosis should always be made, allowing for a rapid switch to SU.

Evaluation of the Architect® tacrolimus assay in kidney, liver, and heart transplant recipients

The narrow therapeutic range of tacrolimus requires therapeutic drug monitoring to prevent transplant rejection and to minimize nephrotoxicity. The aim of this study was to evaluate the analytical performance of the tacrolimus chemiluminescent microparticle immunoassay (CMIA) in everyday practice comparatively with other methods. CMIA imprecision and accuracy were tested using low, medium, and high concentrations in control samples. The limits of quantification (LOQ) of CMIA and antibody-conjugated magnetic immunoassay (ACMIA) were evaluated using negative whole-blood samples containing 0.4-5.7 ng/ml of tacrolimus from a stock solution. CMIA was compared with ACMIA, enzyme multiplied immunoassay (EMIT), and liquid chromatography-tandem mass spectrometry (LC-MS/MS), using 176 samples from recipients (135 men and 41 women) of heart (n=19), kidney (n=107), or liver (n=50) transplants. CMIA total precision was 5.7%, 3.7% and 3.6% with the low-, medium-, and high-concentration controls, respectively; corresponding values for accuracy were 98%, 104%, and 104%. LOQ was 0.5 (95%CI, 0.22-1.38) with CMIA and 2.5 ng/ml with ACMIA. Linear regression results were as follows: CMIA=1.2LC-MS/MS+0.14 (r=0.98); CMIA=0.93EMIT+0.36 (r=0.975); CMIA=1.15ACMIA-0.25 (r=0.988); and, for tacrolimus concentrations in the 1-15 ng/ml range, of special interest as many transplant recipients are given low-dose tacrolimus, CMIA=1.05LC-MS/MS+0.38 (r=0.94). Two patients had falsely elevated tacrolimus concentrations due to interference in the ACMIA assay; one was a renal transplant recipient who stopped her treatment and had tacrolimus concentrations of 12.5 ng/ml by ACMIA and <0.5 ng/ml by CMIA; the other was an HIV-positive renal transplant recipient whose tacrolimus concentrations by ACMIA were 1.8-43.7-fold those by CMIA. Such interferences with ACMIA, which may be related to endogenous antibodies in the plasma, are likely to negatively impact patient care. In conclusion, the tacrolimus CMIA assay is suitable for routine laboratory use and does not suffer from the interferences seen with ACMIA in some patients.

Population pharmacokinetics of nefopam in elderly, with or without renal impairment, and its link to treatment response

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.

Determination of articaine in human plasma by liquid chromatography-mass spectrometry and its application in a preliminary pharmacokinetic study.

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.

Erratum. Sulfonylurea Therapy Benefits Neurological and Psychomotor Functions in Patients With Neonatal Diabetes Owing to Potassium Channel Mutations. Diabetes Care 2015;38:2033–2041

The online version reflects these changes. Mutations n of patients; patient no. KCNJ11 G228A n 5 1; 13 E227K n 5 1; 14 E292G n 5 1; 10 H186D n 5 1; 5 I182T n 5 1; 9 Q51G n 5 1; 8 R201C n 5 2; 16, 18 R201H n 5 7; 1, 2, 3, 7, 11, 15, 17 V59M n 5 1; 12 ABCC8 R1183W n 5 1; 4 R1380H n 5 1; 6 Jacques Beltrand, Caroline Elie, Kanetee Busiah, Emmanuel Fournier, Nathalie Boddaert, Nadia Bahi-Buisson, Miriam Vera, Emmanuel Bui-Quoc, Isabelle Ingster-Moati, Marianne Berdugo, Albane Simon, Claire Gozalo, Zoubir Djerada, Isabelle Flechtner, Jean-Marc Treluyer, Raphael Scharfmann, Helene Cavé, Laurence Vaivre-Douret, and Michel Polak, on behalf of the GlidKir Study Group Diabetes Care Volume 39, January 2016 175

Clinical and analytical toxicology of opiate, cocaine and amphetamine

In several circumstances, determination and quantification of illicit drugs in biological fluids are determinant. Contexts are varied such as driving under influence, traffic accident, clinical and forensic toxicology, doping analysis, chemical submission. Whole blood is the favoured matrix for the quantification of illicit drugs. Gas chromatography coupled with mass spectrometry (GC-MS) is the gold standard for these analyses. All methods developed must be at least equivalent to gas chromatography coupled with a mass spectrometer. Nowadays, new technologies are available to biologists and clinicians: liquid chromatography coupled with a mass spectrometry (LC/MS) or coupled with a tandem mass spectrometer (LC/MS/MS). The aim of this paper is to describe the state of the art regarding techniques of confirmation by mass spectrometry used for quantification of conventional drugs except cannabis.

Population pharmacokinetics of articaine with 1:200,000 epinephrine during third molar surgery and simulation of high-dose regimens

Background and objectives Articaine is more and more used in third molar surgery under local anesthesia (LA). The objectives of this analysis were to characterize the pharmacokinetics of articaine for this type of surgery and to simulate dosing regimens. Methods Non‐linear mixed‐effects modeling conducted in Monolix 4.4.0 was used to describe articaine plasma concentration‐time data from 20 patients. Monte Carlo simulations were then performed to evaluate the probability of cardiotoxic target attainment (PCTA) of various dosage regimens. Results Articaine concentration data were best described by a linear one‐compartment model, with an additional depot compartment for submucosal route with a zero‐order transfer to central compartment. Age and gender were found to influence duration transfer (Tk0) and elimination rate constant (Ke), respectively. Simulated maximum recommended dose regimen (7 mg/kg) had a PCTA of 0%. Simulated higher doses of 10 mg/kg and 15 mg/kg had a PCTA of 0% and about 1–4%, respectively. Conclusions The model adequately described the articaine pharmacokinetics. This is the first PK model qualified for articaine administered by submucosal route. The simulations suggest that maximum recommended dose regimen is safe concerning the cardiotoxicity in healthy patients. Graphical abstract Figure. No caption available.

Somnolence et fièvre inhabituelle chez un enfant après ingestion de cannabis

Trivialization of cannabis consumption goes hand in hand with a growing exposure of children and the number of cannabis poisoning cases is steadily increasing. As clinical presentation can be different from what is currently seen in adults, added to the fact that it is not always suspected, diagnosis of cannabis intoxication in children is often delayed or missed. A 16-month-old girl was admitted to the pediatric emergency unit for an important drowsiness combined to moderate fever. After elimination of infectious causes, a toxic origin was considered and biological analyses led to the diagnosis of involuntary acute cannabis intoxication. In conclusion, cannabis intoxication in child has uncommon presentations compared to that seen in adults. In this context, biological analyses have a great importance for a rapid diagnosis and also for the understanding intoxication circumstance. This is of paramount importance because it may lead to consider child protection measures.

Faux négatif lors d’une intoxication avérée chez deux enfants par le lorazépam

Children aged between 1 to 4 years are the most at risk of unintentional poisonings. Benzodiazepines are the most medicine often cause of the poisoning. Among the twenty-two most prescribed benzodiazepines in France, lorazepam ranks fifth behind zolpidem, alprazolam, bromazepam and zopiclone. However the automated assay currently available does not allow to detect and/or to quantify lorazepam. The alternative to the immunoassay is the liquid chromatography coupled with mass spectrometry (HPLC/MS). This technique, highly sensitive and specific, requires a pre-treatment phase and a good technical proficiency, justifying specialized staff. The clinical cases presented here illustrate the major interest of availability to this type of technology in routine and 24h/24h.