Impact of CYP2D6*10 on mexiletine pharmacokinetics in healthy adult volunteers.

Objective: In vitro studies with human liver microsomes have suggested that the oxidative conversion of mexiletine (MX) to its metabolites is catalyzed by CYP2D6 and is significantly impaired in microsomes with the CYP2D6*10/*10 genotype. Therefore, we examined the influence of the CYP2D6*10 allele on MX pharmacokinetics in Japanese subjects.

Methods: Subjects with CYP2D6*1/*1 (group *1/*1; n=5), CYP2D6*10/*10 (group *10/*10; n=6) and CYP2D6*5/*10 (group *5/*10; n=4) genotypes received a single 200-mg dose of MX.