Characterization and identification of eight designer benzodiazepine metabolites by incubation with human liver microsomes and analysis by a triple quadrupole mass spectrometer.
Designer benzodiazepines (DBZDs) have become of particular importance in the past few years. The metabolite monitoring of DBZD in biological fluids could be of great interest in clinical and forensic toxicology. However, DBZD metabolites are not known or not commercially available. The identification of some DBZD metabolites has been mostly explored by self-administration studies or by in vitro studies followed by high-resolution mass spectrometry. The question arose whether a unit resolution instrument could be efficient enough to allow the identification of DBZD metabolites. In this study, we used an in vitro experiment where eight DBZDs (diclazepam, flubromazepam, etizolam, deschloroetizolam, flubromazolam, nifoxipam, meclonazepam and clonazolam) were incubated with human liver microsomes (HLMs) and metabolite identification was carried out by using a UHPLC coupled to a QTRAP triple quadrupole linear iontrap tandem mass spectrometer system. Post-mortem samples obtained from a real poisoning case, involving deschloroetizolam and diclazepam, were also analysed and discussed. Our study using HLM allowed the identification of 26 metabolites of the 8 DBZDs. These were denitro-, mono- or di-hydroxylated and desmethyl metabolites. In the forensic case, diclazepam was not detected whereas its metabolites (lormetazepam and lorazepam) were present at high concentrations in urine. We also identified hydroxy-deschloroetizolam in urine, while the parent compound was not detected in this matrix. This supports the approach that LC coupled to a simple QTRAP could be used by laboratories to identify other not-known/not-commercialized new psychoactive substance (NPS) metabolites.
Department of Pharmacology, Service de pharmacologie, toxicologie et pharmacovigilance, CHU de Limoges, Limoges University Hospital, 2 Ave Martin Luther King, 87042, Limoges Cedex, France. souleiman.elbalkhi@chu-limoges.fr.|INSERM, U850, 87000, Limoges, France. souleiman.elbalkhi@chu-limoges.fr.
Souleiman
S
El Balkhi
Department of Pharmacology, Service de pharmacologie, toxicologie et pharmacovigilance, CHU de Limoges, Limoges University Hospital, 2 Ave Martin Luther King, 87042, Limoges Cedex, France.
Maxime
M
Chaslot
Department of Pharmacology, Service de pharmacologie, toxicologie et pharmacovigilance, CHU de Limoges, Limoges University Hospital, 2 Ave Martin Luther King, 87042, Limoges Cedex, France.|INSERM, U850, 87000, Limoges, France.|Université Limoges, UMR_S 850, 87000, Limoges, France.
Nicolas
N
Picard
Department of Pharmacology, Service de pharmacologie, toxicologie et pharmacovigilance, CHU de Limoges, Limoges University Hospital, 2 Ave Martin Luther King, 87042, Limoges Cedex, France.
Sylvain
S
Dulaurent
Department of Medical Pharmacology and Toxicology, CHU de Montpellier, Montpellier, France.
Martine
M
Delage
Department of Medical Pharmacology and Toxicology, CHU de Montpellier, Montpellier, France.|Department of Medical Pharmacology and Toxicology, CHU de Montpellier, UMR 5569 Hydrosciences Montpellier, Montpellier University Hospital-Montpellier University, Montpellier, France.
Olivier
O
Mathieu
Department of Pharmacology, Service de pharmacologie, toxicologie et pharmacovigilance, CHU de Limoges, Limoges University Hospital, 2 Ave Martin Luther King, 87042, Limoges Cedex, France.|INSERM, U850, 87000, Limoges, France.|Université Limoges, UMR_S 850, 87000, Limoges, France.
Franck
F
Saint-Marcoux
D000328:Adult; D001569:Benzodiazepines / Q000032:analysis / Q000737:chemistry*; D002853:Chromatography, Liquid; D015198:Designer Drugs / Q000032:analysis / Q000737:chemistry*; D006801:Humans; D008140:Lorazepam / Q000031:analogs & derivatives / Q000652:urine; D008297:Male; D008862:Microsomes, Liver / Q000737:chemistry*; D010076:Oxazepam / Q000652:urine; D019966:Substance-Related Disorders / Q000652:urine; D053719:Tandem Mass Spectrometry
D015198:Designer Drugs; D001569:Benzodiazepines; D010076:Oxazepam; C023842:lormetazepam; D008140:Lorazepam
Deschloroetizolam; Designer benzodiazepines; General unknown screening; Human liver microsomes; NPS; New psychoactive substances; QTRAP