title: Effects of CYP2C19 variants on methadone metabolism in vitro.
abstract: CYP2C19 is an important member of the cytochrome P450 (CYP450) enzyme super family and is responsible for clearing approximately 10% of commonly used clinical drugs that undergo phase I metabolism. Genetic polymorphisms of CYP2C19 significantly influence the efficacy and safety of some drugs, which might cause undesirable adverse effects or cure failure at standard dosages. The aim of this study was to clarify the catalytic activities of 31 CYP2C19 alleles on the oxidative in vitro metabolism of methadone. Insect microsomes expressing the CYP2C19 alleles were incubated with 50-2000 μM methadone for 30 min at 37 °C and terminated by cooling to -80 °C immediately. Methadone and its metabolite EDDP were analyzed by an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) system. Of the 31 tested CYP2C19 allelies variants, CYP2C19*1 is the wild-type. Compared with CYP2C19*1, two CYP2C19 variants (CYP2C19*3 and *35FS) had no detectable enzyme activity, one variant L16F exhibited slightly increased intrinsic clearance values, and one variant N277K showed no significant difference. In addition, 26 variants exhibited significantly decreased values (from 1.48% to 80.40%). These findings suggest that more attention should be paid in clinical administration of methadone to individuals carrying these CYP2C19 alleles. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Lan
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, China.
authors.forename: Ling-Jing
authors.initials: LJ
authors.lastname: Yuan
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, China.
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Hu
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325027, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, China.
authors.forename: Xiang-Xin
authors.initials: XX
authors.lastname: Huang
authors.affiliation: The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, China.
authors.forename: Da-Peng
authors.initials: DP
authors.lastname: Dai
authors.affiliation: The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, China.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Cai
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, China.
authors.forename: Guo-Xin
authors.initials: GX
authors.lastname: Hu
mesh_terms: D000701:Analgesics, Opioid / Q000378:metabolism*; D000818:Animals; D065731:Cytochrome P-450 CYP2C19 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008691:Methadone / Q000378:metabolism*; D011110:Polymorphism, Genetic; D061987:Sf9 Cells; D018411:Spodoptera
chemical_list: D000701:Analgesics, Opioid; D065731:Cytochrome P-450 CYP2C19; D008691:Methadone
keywords: CYP2C19 polymorphism; N-demethylation; allelic variant; drug metabolism; methadone