The effect of perazine on the CYP2D6 and CYP2C19 phenotypes as measured by the dextromethorphan and mephenytoin tests in psychiatric patients

• Published in: Basic & clinical pharmacology & toxicology 2020-05, Vol.126 (5), p.444-447
• Main Authors: Baumann, Pierre, Eap, Chin B., Gastpar, Markus
• Format: Article
• Language: English
• Subjects: Adult; Antipsychotic Agents - pharmacology; Antipsychotics; CYP2C19; CYP2D6; CYP2D6 protein; Cytochrome P-450 CYP2C19 - metabolism; Cytochrome P-450 CYP2D6 - metabolism; Cytochrome P-450 CYP2D6 Inhibitors - pharmacology; Cytochrome P450; Dextromethorphan; Dextromethorphan - metabolism; Drug Interactions; Female; Humans; Male; Mephenytoin - metabolism; Metabolites; Middle Aged; perazine; Perazine - pharmacology; Pharmacogenetics; pharmacokinetic interaction; Pharmacokinetics; Phenotype; Phenotypes; Phenotyping; psychiatric patients; Schizophrenia - drug therapy; Schizophrenia - enzymology; Substrates; Young Adult
• ISSN: 1742-7835; 1742-7843
• DOI: 10.1111/bcpt.13373

There is evidence that the antipsychotic drug perazine is an inhibitor of CYP2D6. This study aimed at evaluating its effect on CYP2D6 and CYP2C19 activities in submitting psychiatric patients to phenotyping with dextromethorphan and mephenytoin, respectively, substrates of these enzymes, before and during a treatment with perazine. A total of 31 patients were phenotyped with dextromethorphan (CYP2D6) and mephenytoin (CYP2C19) before and after a 2‐week treatment with 450 ± 51 mg/day (mean ± sd) perazine. At baseline, five patients appeared to be poor metabolizers (PM) of dextromethorphan and two patients of mephenytoin. The metabolic ratio (MR) of dextromethorphan/dextrorphan as determined in collected urine increased significantly (Wilcoxon; P