Relevance of CYP2B6 and CYP2D6 genotypes to methadone pharmacokinetics and response in the OPAL study.

AIMS: Our study aimed to evaluate the impacts of the cytochrome P450 (CYP) 2B6-G516T and CYP2D6 genetic polymorphisms on pharmacokinetic and clinical parameters in patients receiving methadone maintenance treatment. METHODS: Opioid PhArmacoLogy (OPAL) was a clinical survey of the sociodemographic characteristics, history and consequences of pathology associated with methadone maintenance treatment response and current addictive comorbidities. A subgroup of 72 methadone patients was genotyped. RESULTS: When comparing the three CYP2B6 genotype groups, the methadone (R)- and (S)-methadone enantiomer concentrations/doses (concentrations relative to doses) were different (P = .029, P = .0019). The CYP2D6 phenotypes did not seem to be relevant with regard to methadone levels. On multivariate analysis, neither the CYP2B6 genotype nor the CYP2D6 phenotype explained the (R)-methadone concentration/dose values (P = .92; P = .86); the (S)-methadone concentration/dose values (P = .052; P = .95 [although there was a difference between the TT group and GT and GG groups {P = .019}]); or opiate cessation (P = .12; P = .90). CONCLUSION: The genotyping of CYP2B6 G516T could be an interesting tool to explore methadone intervariability.

Use of psychotropic drug urine test strips in opiate maintenance therapy: A clinical assessment of its advantages.

BACKGROUND: Methadone and buprenorphine are the 2 opiate maintenance treatments (OMTs) available in France. According to good clinical practices, a full clinical and biological assessment is required before deciding to initiate or renew an OMT. For methadone, this assessment includes psychoactive drug consumption investigation through an initial interview completed by a systematic urine test mandatory before starting methadone treatment. In case of buprenorphine prescription, the situation is less clear and the urine test was not systematically performed. This work aims at evaluating changes in the therapeutic strategy brought by the systematic use of urine strips for detecting drug consumptions. METHODS: During 1 month, for each case of OMT renewal, physicians belonging to the 3 types of prescribing structures in France (general medicine, specialized centers for drug addict patients, and specialized centers for drug addict patients in prison) had to complete a specific questionnaire about prescription renewal. This questionnaire contained 2 parts. The first part was completed by the physicians before the urine test strip realization. The second part was completed by the same physicians at the end of the consultation, after obtaining the results from the urine test strip. A change between parts 1 and 2 of the questionnaire concerning OMT prescription, dialogue with the patient, associated psychotropic drug prescription, and orientation were considered as a change in therapeutic strategy. RESULTS: A total of 429 questionnaires have been collected. Among them, 315 showed at least 1 change in therapeutic strategy (73.4%). CONCLUSIONS: This study highlighted the important benefits brought by the urine test strip in managing patients under opiate maintenance treatment. Urine test strips provided an immediate answer that allowed physicians to optimize their therapeutic strategy. However, regulatory evolutions would be necessary to ease their implantation.

Influence of nevirapine administration on the pharmacokinetics of dolutegravir in patients infected with HIV-1.

OBJECTIVES: The metabolic pathways of dolutegravir and nevirapine suggest a potential pharmacokinetic interaction between these drugs. The objective of this study was to investigate the influence of nevirapine administration on the pharmacokinetics of dolutegravir in patients infected with HIV-1. PATIENTS AND METHODS: This study was an investigator-initiated trial registered at ClinicalTrials.gov under identifier NCT02067767. Dolutegravir (50 mg once daily) was added to the antiretroviral regimen (400 mg of nevirapine once daily + 600/300 mg of abacavir/lamivudine once daily) in 10 adult patients for 5 days. After discontinuation of nevirapine, the combination of dolutegravir + abacavir/lamivudine was continued. Full pharmacokinetic profiles were assessed on the day of nevirapine discontinuation and 2 weeks after discontinuation of nevirapine. The pharmacokinetic parameters of dolutegravir were calculated by non-compartmental analysis. The log-transformed values of these parameters were compared between periods with and without nevirapine co-administration. RESULTS: The co-administration of nevirapine led to a significant decrease (P < 0.05) in the area under the plasma concentration-time curve for dolutegravir from the time the dose was administered until the end of the dosing interval (-19%, P = 0.011), as well as decreases in trough plasma concentration (-34%, P = 0.018) and terminal half-life (-15%, P = 0.039), and a significant increase (P < 0.05) in apparent oral clearance for dolutegravir (+23%, P = 0.011). CONCLUSIONS: The decrease in dolutegravir exposure in combination with nevirapine suggests that the metabolism of dolutegravir is induced by nevirapine. According to therapeutic drug monitoring for dolutegravir, some patients may need a higher dose than 50 mg of dolutegravir once daily to maintain the therapeutic plasma concentration throughout the dosing interval.

Evaluation of the QMS® Teicoplanin Immunoassay (ThermoFisher Scientific) on Cobas® 8000 System (Roche Diagnostics) and comparison to fluorescence polarization immunoassay for the determination of teicoplanin concentrations in human plasma.

BACKGROUND: The performances of the QMS(®) Teicoplanin immunoassay recently developed on Cobas(®) 6000/8000 systems were evaluated and compared to a fluorescence polarization immunoassay (FPIA) [Teicoplanin Innofluor(®) Assay (Thermo Fisher Scientific, Indianapolis, IN)] on FLX analyzer (Abbott Laboratories, Abbott Park, IL)]. METHODS: The validation was performed according to the Cofrac (French Accreditation Committee) document SH GTA 04. For the comparison, 48 plasma samples were analyzed by FPIA and QMS assays. RESULTS: The QMS assay is accurate (intra assay and inter assay inaccuracy ≤ 2.4%) and precise (intra assay and inter assay imprecision ≤ 10.2%). A linear relationship [QMS = 1.0319 × FPIA - 2.8518, r(2) = 0.9246 (P < 0.001)] between FPIA and QMS was found. In the Bland-Altman plots, no systematic bias was found even if QMS results trends to be lower (mean of the ratio QMS concentration/FPIA concentration = 0.91). CONCLUSION: These results between QMS and FPIA are consistent, which indicates that QMS(®) Teicoplanin immunoassay on Cobas(®) 8000 System is an alternative to FPIA.

[Level of evidence for therapeutic drug monitoring of ceftriaxone]. / Niveau de preuve du suivi thérapeutique pharmacologique de la ceftriaxone.

Ceftriaxone is a third generation cephalosporin with an original pharmacokinetics based on a long elimination half-life among cephalosporins, a high protein binding and a dual renal and biliary elimination. Also the pharmacokinetic parameters of ceftriaxone are highly variable in clinical situations such as severe renal insufficiency, liver and renal insufficiency, the elderly, the neonates less than 1 week of age and critically ill patients. In these clinical situations associated or not with high minimal inhibitory concentration (MIC) level, the relationship concentration-clinical outcome based on the ratio between trough plasma concentration and MIC can allow a dose adjustment. Consequently, therapeutic drug monitoring (TDM) of ceftriaxone could be possibly useful in these situations, whereas the necessity of TDM has still to be demonstrated to monitor toxicity.

Comparative effects of 15 antidepressants on the risk of withdrawal syndrome: A real-world study using the WHO pharmacovigilance database.

BACKGROUND: While case reports and clinical trials reported withdrawal syndrome after reduction and/or discontinuation of antidepressant drugs, no large study has been conducted to compare the risk between the different antidepressants. METHODS: Using data recorded from January 1st, 1988, and December 31st, 2020 in VigiBase®, the World Health Organization's Global Individual Case Safety Reports database, we performed disproportionality analysis to investigate the risk of reporting withdrawal syndrome in patients treated by short half-life antidepressants compared with patients treated by long half-life antidepressants. In addition, we aimed to better inform clinical practice by comparing 15 antidepressants for the risk of reporting withdrawal syndrome. RESULTS: Among the 338,498 reports with antidepressants of interest, we found 15,507 cases of withdrawal syndrome. Short half-lives antidepressants were associated with an increased risk of reporting a withdrawal syndrome compared to long half-life antidepressants (ROR 5.38; 95% CI 5.16-5.61). The risk was higher for 18-44 years old (ROR 6.88; 95% CI 6.17-7.62), women (ROR 1.38; 95% CI 1.33-1.43) and patients treated with Paroxetine, Desvenlafaxine, Venlafaxine and Duloxetine. LIMITATIONS: The limitations of this study stem from the case-reporting process. CONCLUSIONS: This large observational study in a real-world setting suggests that the use of short half-life antidepressants increases the risk of reporting withdrawal syndrome compared to long half-life antidepressants. Among the most common antidepressants, paroxetine and serotonin-noradrenaline reuptake inhibitors are associated with a greater risk of reporting withdrawal syndrome, while agomelatine and vortioxetine present a lower risk. Additional studies are needed to corroborate our results.

Colchicine-induced rhabdomyolysis in a heart/lung transplant patient with concurrent use of cyclosporin, pravastatin, and azithromycin.

We report a case of colchicine-induced rhabdomyolysis in a heart/lung-transplanted man treated with cyclosporin. A treatment was to resolve an acute gouty arthritis and was started with 3 mg of colchicine the first day, then 2 mg the second and the third day, and finally 1 mg/d during 6 days. Eight days later, the patient developed multiple organ failure and rhabdomyolysis. The concentration of colchicine analyzed was greater than the standard 153 hours after his last intake. Pharmacokinetic interactions are responsible of this toxicity. Cyclosporin, pravastatin, and azithromycin are known to inhibit P-glycoprotein, which will enhance the intracellular colchicine level by acting in its bioavailability and moderating hepatic and renal excretion. Moreover, long-term treatment by cyclosporin generates chronic renal failure that will, in the same time, decrease colchicine elimination. Even short-term administration of therapeutic colchicine dose may cause colchicine-related toxicity, especially in the setting of a renal failure and/or polymedicinal treatment.

[Not Available]. / Suivi thérapeutique pharmacologique de l'oxcarbazépine.

Oxcarbazepine is an analogue of carbamazepine, used for the treatment of partial seizure with or without secondary generalization. The two forms R and S of the mono-hydroxylated derivatives (MHD) are responsible for most of the anti-convulsant activity and it is the concentrations of MHD that are relevant in therapeutic drug monitoring (TDM). Analysis of currently literature provides no well-established relationship between plasma concentration of MHD and efficiency or toxicity. Although there is not a validated therapeutic range, the residual concentrations of usually observed therapeutic MHD are situated between 12 and 30 mg/L. In certain pathological or physiological circumstances, the pharmacokinetic variability of the oxcarbazepine can be considerable, but this strong unpredictability does not nevertheless justify the TDM of the MHD. Based on the available evidence, TDM of MHD is not routinely warranted but may be possibly useful in specific situations such as pregnancy or renal insufficiency.

[Not Available]. / Suivi thérapeutique pharmacologique du lévétiracétam.

Levetiracetam is an anticonvulsant drug used to treat partial seizures, myoclonic seizures of juvenile myoclonic epilepsy and primary generalized tonic-clonic seizures. A review of the literature with an evidence-based medicine method highlighted parameters (age, renal failure, pregnancy, combination with other anticonvulsant drugs) which affect levetiracetam pharmacokinetics but no significant relationship between plasma concentration of levetiracetam and efficacy or toxicity. Concentrations usually observed in therapeutics is from 6 to 18 mg/L. However, the determination of an individual therapeutic concentration, associated with an effective and well tolerated therapy, could be recommended particularly before pregnancy. Consequently, therapeutic drug monitoring of leve-tiracetam which is not currently recommended could be possibly useful in specific clinical situations.

[Therapeutic drug monitoring of oxcarbazepine]. / Suivi thérapeutique pharmacologique de l'oxcarbazépine.

Oxcarbazepine is an analogue of carbamazepine, used for the treatment of partial seizure with or without secondary generalization. The two forms R and S of the mono-hydroxylated derivatives (MHD) are responsible for most of the anti-convulsant activity and it is the concentrations of MHD that are relevant in therapeutic drug monitoring (TDM). Analysis of currently literature provides no well-established relationship between plasma concentration of MHD and efficiency or toxicity. Although there is not a validated therapeutic range, the residual concentrations of usually observed therapeutic MHD are situated between 12 and 30 mg/L. In certain pathological or physiological circumstances, the pharmacokinetic variability of the oxcarbazepine can be considerable, but this strong unpredictability does not nevertheless justify the TDM of the MHD. Based on the available evidence, TDM of MHD is not routinely warranted but may be possibly useful in specific situations such as pregnancy or renal insufficiency.

[Therapeutic drug monitoring of levetiracetam]. / Suivi thérapeutique pharmacologique du lévétiracétam.

Levetiracetam is an anticonvulsant drug used to treat partial seizures, myoclonic seizures of juvenile myoclonic epilepsy and primary generalized tonic-clonic seizures. A review of the literature with an evidence-based medicine method highlighted parameters (age, renal failure, pregnancy, combination with other anticonvulsant drugs) which affect levetiracetam pharmacokinetics but no significant relationship between plasma concentration of levetiracetam and efficacy or toxicity. Concentrations usually observed in therapeutics is from 6 to 18 mg/L. However, the determination of an individual therapeutic concentration, associated with an effective and well tolerated therapy, could be recommended particularly before pregnancy. Consequently, therapeutic drug monitoring of levetiracetam which is not currently recommended could be possibly useful in specific clinical situations.

A fast and efficient HLA multimer-based sorting procedure that induces little apoptosis to isolate clinical grade human tumor specific T lymphocytes.

HLA multimers are now widely used to stain and sort CD8 T lymphocytes specific for epitopes from viral or tumoral antigens presented in an HLA class I context. However, the transfer of this technology to a clinical setting to obtain clinical grade CD8 T lymphocytes that may be used in adoptive cell transfer (ACT) is hindered by two main obstacles: the first obstacle is the use of streptavidin or derived products that are not available in clinical grade to multimerize HLA/peptide monomers and the second is the reported high degree of apoptosis that eventually occurs when T cell receptors are crosslinked by HLA multimers. In the present report, we describe new HLA multimers composed of immunomagnetic beads covalently coupled to a mAb specific for the AviTag peptide and coated with HLA/peptide monomers bearing the non biotinylated AviTag at the COOH terminus of the HLA heavy chain. Thus, all the components of this new reagent can be obtained in clinical grade. We compared these new multimers with the previously described multimers made with streptavidin beads coated with biotinylated HLA/peptide monomers, in terms of sorting efficiency, recovery of functional T cells, apoptosis and activation. We provide evidence that the new multimers could very efficiently sort pure populations of T lymphocytes specific for three different melanoma antigens (Melan-A, gp100 and NA17-A) after a single peptide stimulation of melanoma patients' PBMC. The recovered specific T cells were cytotoxic against the relevant melanoma cell-lines and, in most cases, produced cytokines. In addition, in marked contrast with streptavidin-based multimers, our new multimers induced very little apoptosis or activation after binding specific T lymphocytes. Altogether, these new multimers fulfill all the necessary requirements to select clinical grade T lymphocytes and should facilitate the development of ACT protocols in cancer patients.

Cannabis and anticancer drugs: societal usage and expected pharmacological interactions - a review.

Cannabis is a plant that has been used for centuries to relieve a wide range of symptoms. Since the 1960s, interest in medical research into this plant has grown steadily. Already very popular for recreational use, a growing number of consumers not accustomed to using cannabis for psychoactive purposes have begun to use it as an alternative or complement to mainstream pharmaceutical medicines. The principal unsubstantiated or 'social' uses of cannabis are based mainly on data that is at best controversial, but usually not scientifically proven. The aim of this review was to identify the scientific basis and reasons that lead patients with cancer to consume cannabis, and also to identify whether there is a risk of interaction between cannabis and anticancer medicines through drug transporters (P-glycoprotein and other ATP-binding cassette superfamily members) Cytochromes P450 (3A, 1A, 2B, 2C, 2D families…) and glucuronyl transferases.

Evaluation of a Methotrexate Chemiluminescent Microparticle Immunoassay: Comparison to Fluorescence Polarization Immunoassay and Liquid Chromatography-Tandem Mass Spectrometry.

OBJECTIVES: For most laboratories, methotrexate (MTX) concentrations are routinely monitored by fluorescence polarization immunoassay (FPIA). In anticipation of an announced withdrawal of the FPIA reagent on the Abbott TDxFLx (Abbott Diagnostics, Abbott Park, IL), we have evaluated a new reagent kit developed by Abbott on the Architect i1000, based on chemiluminescent microparticle immunoassay (CMIA). METHODS: Precision, inaccuracy, and selectivity were assessed. Interassay variability was established using 75 plasma patient samples treated with MTX and analyzed by two methods: FPIA and liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS FOR MTX,: the intraday inaccuracy was between -6.37% and +3.52%, while interday performance was between -3.70% and 7.90%. Intraday and interday imprecision was less than 2.65% and less than 2.22%, respectively. The correlation coefficient between CMIA and FPIA or LC-MS/MS was 0.9969 and 0.9985, respectively. CONCLUSIONS: These results comparing CMIA vs FPIA and LC-MS/MS indicate that CMIA is a suitable alternative to the FPIA method.

Stability and Compatibility of Antibiotics in Peritoneal Dialysis Solutions Applied to Automated Peritoneal Dialysis in The Pediatric Population.

♦ OBJECTIVES: Assess the stability of several antibiotics in peritoneal dialysis (PD) solutions under common conditions of use in pediatrics, particularly in automated PD. ♦ METHODS: Amoxicillin, cefazolin, cefepime, ceftazidime, imipenem, cotrimoxazole, tobramycin, vancomycin, and the association of ceftazidime + vancomycin and ceftazidime + tobramycin, were tested in 3 different PD solutions: bicarbonate/lactate solution with 2 glucose concentrations (Physioneal 1.36 and 3.86%; Baxter Healthcare Corporation, Deerfield, IL, USA) and an icodextrin-containing solution (Extraneal; Baxter Healthcare Corporation, Deerfield, IL, USA). Concentrations were those recommended in guidelines for the treatment of peritonitis in pediatrics. Physioneal bags were incubated at 37°C for 24 hours, whereas Extraneal bags were stored 12 hours at room temperature (22 ± 2°C) and then 12 hours at 37°C. Drug concentrations were determined using high performance liquid chromatography (HPLC). Each measure was taken in triplicate. Stability of antibiotics was defined as less than 10% degradation of the drug over time. ♦ RESULTS: Cefazolin, cotrimoxazole, tobramycin, and vancomycin were stable under studied conditions. Ceftazidime was stable 24 hours in icodextrin, 12 hours in Physioneal 1.36% and 6 hours in Physioneal 3.86%. The association of tobramycin or vancomycin did not influence the stability of ceftazidime. Cefepime and amoxicillin were stable 6 h, 4 h, and 8 h in Physioneal 1.36%, 3.86% and Extraneal, respectively. The stability of imipenem was very low: 2 h in Physioneal and 6 h in Extraneal. Moreover, an increasingly yellow coloration was observed with the use of imipenem, whereas no color change or precipitation occurred in other bags. ♦ CONCLUSION: Cefazolin, tobramycin, cotrimoxazole, and vancomycin are stable in PD solutions up to 24 hours and can be administered in the PD bag for the treatment of peritonitis, even in automated PD under studied conditions. However, amoxicillin, cefepime, ceftazidime, and imipenem must be used with caution due to their lack of stability.

Disseminated Mucormycosis With Cerebral Involvement Owing to Rhizopus Microsporus in a Kidney Recipient Treated With Combined Liposomal Amphotericin B and Posaconazole Therapy.

Three months after a kidney transplant, a man experienced an internuclear ophthalmoplegia. Magnetic resonance imaging found a punctuate hyperintensity of the brainstem. Afterwards, the patient presented with peripheral facial paralysis. A complete morphologic assessment showed an increase of the brainstem lesion, together with an excavated pulmonary nodule. Combination therapy with high-dose liposomal amphotericin B and voriconazole was begun for the putative aspergillosis. Owing to its atypical clinical presentation and negative detection of Aspergillus galactomannan antigen on sera, a biopsy specimen of the lung lesion was obtained. Histopathological and mycological investigations allowed the diagnosis of mucormycosis owing to Rhizopus microsporus. Accordingly, voriconazole was replaced with posaconazole. After 5 months, regression of the cerebral lesion was noted. Disseminated mucormycosis in solid-organ recipients is uncommon and mycological diagnosis is challenging. Mortality is high and is increased by diagnostic delay. Treating mucormycosis requires surgical debridement and appropriate antifungal therapy (usually intravenous liposomal amphotericin B). This report suggests that a combination of liposomal amphotericin B and posaconazole can be a therapeutic option in patients with a poor prognosis.

Chiral on-line solid phase extraction coupled to liquid chromatography-tandem mass spectrometry assay for quantification of (R) and (S) enantiomers of methadone and its main metabolite in plasma.

The authors aimed at developing a liquid chromatography tandem mass spectrometry (LC-MS/MS) method with online extraction to determine (R)- and (S)- methadone enantiomers and its main metabolite 2-ethylidine-1,5-dimethyl-3,3 diphenylpyrrolidine (EDDP) in plasma. The analysis combined straightforward sample preparation, consisting of protein precipitation with acetonitrile, and an online enrichment by a flush/back-flush cycle before the second dimension chromatography. Using D3-deuterated internal standards allows overcoming significant relative matrix effect. Our method was linear up to 2000 ng/mL. This simple sample preparation provides sensitive (the limit of quantitation is 25 ng/mL for (R,S)-methadone and EDDP and 12.5 ng/mL for (R)- and (S)- methadone), accurate and precise (the intra-day and inter-day imprecision and inaccuracy are lower than 15%) quantification of the plasma concentration of these drugs. We have developed a reliable LC-MS/MS method for both routine therapeutic drug monitoring and pharmacokinetics studies and for toxicology analysis in the setting of methadone treatment or intoxication.

UGT1A1 genotype and irinotecan therapy: general review and implementation in routine practice.

Irinotecan is a major drug in the treatment of advanced colorectal cancer. Its active form is the SN38 metabolite, which is cleared by the biliary route after glucuronidation by uridine diphosphate-glucuronosyltransferase 1A1 (UGT1A1). UGT1A1 activity exhibits a wide intersubject variability, in part related to UGT1A1 gene polymorphisms. The present review on the impact of the deficient UGT1A1*28 variant on irinotecan efficacy and toxicity was produced by a French joint workgroup comprising the Group of Clinical Onco-pharmacology (GPCO-Unicancer) and the National Pharmacogenetics Network (RNPGx). It clearly emerges that for irinotecan doses at least equal to 180 mg/m(2) , patients homozygous for the UGT1A1*28 allele are at increased risk of developing hematological and/or digestive toxicities. Irinotecan dose reduction is thus recommended in homozygous *28/*28 patients. In addition, this personalized medicine strategy aims to secure high-dose irinotecan administration (≥240 mg/m(2) ) that have proven to be safe in homozygous *1/*1 patients only. The clinical relevance of this test is discussed in terms of treatment efficacy improvement, as increasing the irinotecan dose appears to be safe in patients not bearing a deficient allele. Best execution practices, cost-effectiveness, and result interpretation are discussed with the aim of facilitating the implementation of this analysis in clinical practice. The existence of networks of laboratories performing this test in routine hospital treatment, as in France, offers the prospect of widespread screening, thus guaranteeing equal access to safe treatment and optimized therapy for patients receiving irinotecan-based therapy in advanced colorectal cancer.

Clinical relevance of the interaction when switching non-nucleoside reverse transcriptase inhibitors in patients infected with HIV.

Substitution of a non-nucleoside reverse transcriptase inhibitor (NNRTI) with another drug of the same class combined with nucleoside reverse transcriptase inhibitors is a therapeutic strategy that can improve the tolerability of antiretroviral treatment. According to the pharmacokinetic properties of NNRTIs, this substitution generates pharmacokinetic drug interactions between NNRTIs, which could decrease NNRTI exposure and virological efficacy during the introductory phase of the new NNRTI. Pharmacokinetics and clinical data are reviewed to estimate the risk for switching from efavirenz to nevirapine, efavirenz to etravirine, efavirenz to rilpivirine and nevirapine to rilpivirine.