Catherine Feliu

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.

Current knowledge on the role of P2Y receptors in cardioprotection against ischemia-reperfusion.

During ischemia, numerous effective endogenous extracellular mediators have been identified, particularly, nucleosides such as adenosine as well as purinergic and pyrimidinergic nucleotides. They may play important regulatory roles within the cardiovascular system and notably as cardio-protectants. Indeed, the distribution of the P2Y receptors in mammalian heart includes several cellular constituents relevant for the pathophysiology of myocardial ischemia. Beside the well-known cardioprotective effect of adenosine, the additional protective role of P2Y receptors has emerged. However, interpretation of experimental results may be sometimes perplexing. This is due to the variability of: the experimental models, the endpoints criteria, the chemical structure of agonist and antagonist ligands and their concentrations, the sequences of drug administration with respect to the model used (before and/or during and/or after ischemia). The net effect may be in the opposite direction after a transient or a prolonged stimulation. Nevertheless, the overall reading of published data highlights the beneficial role of the P2Y2/4 receptor stimulation, the useful and synergistic role of P2Y6/11 receptor activation and even of the P2Y11 receptor alone in cardioprotection. More, the P2Y11 receptor could be involved in counter-regulation of profibrotic processes. Paradoxically, transient P2X7 receptor stimulation could contribute to the net cardioprotective effect of ATP. Recently, experimental data have shown that blocking the P2Y12 receptor after ischemia confers cardioprotection independently of platelet antiaggregatory effect. This suggests for P2Y receptors an important role in primary prevention and as a therapeutic target in myocardial protection during ischemia and reperfusion.

Validation of a fast UPLC–MS/MS method for quantitative analysis of opioids, cocaine, amphetamines (and their derivatives) in human whole blood

BACKGROUND Conventional methods for analysis of drugs of abuse require multiple assays which can be both expensive and time-consuming. This work describes a novel, rapid, simple and sensitive method for the quantification of 14 illicit drugs and their metabolites in whole blood. Results/methodology: This method employed a rapid liquid-liquid sample extraction of whole blood followed by UPLC-MS/MS analysis. Calibration curves were validated for analysis of appropriate concentrations. Inter- and intra-assay variations were <14.8%. Deviation of accuracy was <14.9% from target concentration for each quality control level. CONCLUSION This work described the development and the full validation of a precise, sensitive and accurate assay. After validation, this new assay was successfully applied to routine toxicological analysis.

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.

High‐Dose Mitotane‐Induced Encephalopathy in the Treatment of Adrenocortical Carcinoma

We read with great interest the article of Reidy-Lagunes et al. in which the authors evaluated progression of disease and treatment-induced toxicity among a cohort of 36 patients treated with mitotane for metastatic adrenal cortical carcinoma (ACC) [1]. As mentioned by the authors and reported in many retrospective studies, the difficulty of this treatment is the probable requirement of high doses of mitotane to maintain high blood levels within a narrow therapeutic range of concentrations (14–20 mg/L) to induce a beneficial outcome in patients with ACC [2–5]. Indeed, if starting high-dose mitotane monotherapy (4–6 g per day) seemed to induce prolonged survival in patients without significant increase in the rate of toxicity in comparison with low-dose regimen (2–3 g per day) [6, 7], mitotane is not exempt from toxicity. In addition to the toxicities reported by Reidy-Lagunes et al., we report herein a case of mitotaneinduced encephalopathy. A 25-year-old white female patient treated with high dose of mitotane (4 g per day) for ACC presented toxicity signs such as adrenal insufficiency and digestive and neurological toxicity (nausea, vomiting, anorexia, dizziness, memory troubles) that were similar to those reported by Reidy-Lagunes et al. and generally described by Reidy-Lagunes et al., Daffara et al., and Maiter et al. [1, 2, 8]. After 32 weeks of treatment, while a close monitoring and decrease of mitotane dose was already initiated due to an upper-limit concentration of mitotane (Fig. 1), neurological troubles (attention deficit disorder, memory loss, mental depression) worsened. Mitotane treatment was discontinued at 42 weeks of treatment and a performed electroencephalography suggested metabolic encephalopathy. Concomitantly, the determination of mitotane plasma concentration found a concentration of 47.8 mg/L and confirmed a mitotane overdose despite the decrease of its dosage 11 weeks before. Finally, the outcome was favorable after hospitalization in an intensive care unit. One year after tumor resection, no recurrence of malignancy was observed. Although symptoms of neurotoxicity have already been reported, the specific entity of encephalopathy has been rarely described. Indeed, to the best of our knowledge, only Goto et al. reported a case of encephalopathy in a 4-year-old boy with a high-dose mitotane treatment for ACC [9]. Furthermore, a query in the French national pharmacovigilance database from 2004—the date of mitotane commercialization in France—to 2016 found only 14 cases of neurological adverse effects probably related to mitotane, including drowsiness, asthenia, memory disorders, confusion, concentration troubles, headaches, and space-time disorientations, but no case of encephalopathy [10]. It appears that encephalopathy can be a rare but severe adverse event preferentially encountered in high-dose mitotane treatment. A close therapeutic drug monitoring should be performed in case of signs of neurological toxicity to evaluate the exposure of the patient to mitotane. Finally, the decision of mitotane discontinuation should be considered from the early signs of neurotoxicity or in the presence of elevated mitotane blood concentration because mitotane presents a very long terminal half-life (several weeks to several months), leading to an important delay between the decision of treatment discontinuation and the effective decrease of exposure. This case was reported to our Regional Center of Pharmacovigilance.

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.

Analytical interference in the therapeutic drug monitoring of methotrexate.

High-dose of methotrexate chemotherapy is used in the treatment of some tumors. It presents several side effects that required therapeutic drug monitoring, which is commonly performed on 24, 48 and 72h after the beginning of the methotrexate infusion. Treatment of overexposure to methotrexate is based on injection of carboxypeptidase G2, which specifically degrades methotrexate into inactive metabolite: DAMPA. FPIA immunoassay on TDx automated analyzer (Abbott™) was used for therapeutic drug monitoring of methotrexate. This immunoassay presented a significant cross-reactivity between methotrexate and DAMPA, which widely overestimate the residual concentration compared to the gold standard HPLC/MS. TDx automated analyzer was substituted by a new immunoassay on Architect automated analyzer (Abbott™). However, this immunoassay has the same cross-reactivity, which needs to be careful when monitoring methotrexate after an injection of carboxypeptidase G2. In order to determine the most suitable assay for the therapeutic drug monitoring of methotrexate, the knowledge of injection of carboxypeptidase G2 remains essential.