Effect of the CYP3A5 genotype on the pharmacokinetics of intravenous midazolam during inhibited and induced metabolic states.

Objective: Our objective was to investigate the effect of the CYP3A5 genotype on the systemic clearance of midazolam in constitutive, inhibited, and induced metabolic conditions.

Methods: Nineteen healthy volunteers were grouped with regard to the CYP3A5*3 allele, into homozygous wild-type (CYP3A5*1/*1, n = 6), heterozygous (CYP3A5*1/*3, n = 6), and homozygous variant-type (CYP3A5*3/*3, n = 7) subject groups. The pharmacokinetic profile of intravenous midazolam was characterized before and after itraconazole administration (200 mg once daily for 4 days) and also after rifampin (INN, rifampicin) pretreatment (600 mg once daily for 10 days), with a washout period of 2 weeks in between.

Effect of the CYP2D6 genotype on the pharmacokinetics of tropisetron in healthy Korean subjects.

Objective: To evaluate the effect of the CYP2D6 genotype on the pharmacokinetics of tropisetron in healthy Korean subjects.

Methods: A single 5-mg capsule of tropisetron was administered orally to 13 healthy subjects. Plasma concentrations were determined by validated HPLC procedures and data were analyzed by using noncompartmental linear PK methods.