Cytochrome P450 2C19 (CYP2C19)

Cytochrome P450 2C19 (CYP2C19) is a member of the cytochrome P450 superfamily of enzymes. Primarily located in the liver, it functions as a monooxygenase involved in the phase I metabolism of various endogenous compounds and exogenous substances, including approximately 10% of commonly prescribed drugs. Key substrates include clopidogrel, proton pump inhibitors, antidepressants, antiepileptics, and voriconazole. CYP2C19 exhibits significant genetic polymorphism, with common alleles like *1 (wild-type), *2, *3 (loss-of-function), and *17 (gain-of-function) affecting enzyme activity and influencing individual drug responses. This variability necessitates pharmacogenomic testing to personalize medication prescriptions, particularly for drugs like clopidogrel, to optimize efficacy and minimize adverse effects.

Metabolizes drugs via oxidation or activation reactions; influences drug efficacy and toxicity.