Abstract
Cytochrome P450 (CYP) 2C enzymes contribute to the metabolism of about 30% of all drugs. Known polymorphisms of the respective enzymes and drug-drug interactions have a major impact on the efficacy and safety of some CYP2C substrate drugs. In vivo – in vitro correlations including prediction of the effect of such covariates requires quantitative information on enzyme kinetics. In this article there will be a summary of the values of the Michaelis-Menten constant (Km), the maximal velocity (Vmax) and the intrinsic clearance (Clint; Vmax/Km) for 84 substrates (100 reactions) reported to be mediated by CYP2C9 (variant enzymes CYP2C9.1, CYP2C9.2 and CYP2C9.3), CYP2C8 and/or CYP2C19. Particularly contradictory findings for the same reactions call for some standardization in the assessment of enzyme kinetics.
Keywords: CYP2C8, CYP2C9, CYP2C9*2, CYP2C9*3, CYP2C19, kinetics, drug metabolism