The role of CYP2C9 genotype in the metabolism of diclofenac in vivo and in vitro.

Introduction: The polymorphic cytochrome P450 enzyme 2C9 (CYP2C9) catalyses the metabolism of many drugs including S-warfarin, acenocoumarol, phenytoin, tolbutamide, losartan and most of the non-steroidal anti-inflammatory drugs. Diclofenac is metabolised to 4'-hydroxy (OH), the major diclofenac metabolite, 3'-OH and 3'-OH-4'-methoxy metabolites by CYP2C9. The aim of the present study was to clarify the impact of the CYP2C9 polymorphism on the metabolism of diclofenac both in vivo and in vitro.

Pharmacokinetics of losartan and its metabolite E-3174 in relation to the CYP2C9 genotype.

Background And Aim: Losartan is metabolized by polymorphic CYP2C9 to E-3174. Our aim was to evaluate the pharmacokinetics of losartan and E-3174 in relation to the CYP2C9 genotype.

Methods: A 50-mg oral dose of losartan was given to 22 Swedish volunteers with different CYP2C9 genotypes.