Clinical Pharmacogenetics Implementation Consortium Guidelines for Cytochrome P450-2C19 (CYP2C19) Genotype and Clopidogrel Therapy

CYP2C19 is one of the principal enzymes involved in the bioactivation of the antiplatelet prodrug clopidogrel. A common loss-of-function allele, CYP2C19*2 (c.681G>A; rs4244285), is associated with increased risk for serious adverse cardiovascular events in both heterozygous and homozygous patients (~25–50% of the population) with acute coronary syndromes (ACSs) who are receiving clopidogrel, particularly among those undergoing percutaneous coronary intervention (PCI). We provide evidence from published literature and guidelines for CYPC19 genotype–directed antiplatelet therapy (periodically updated at http://www.pharmgkb.org). Clinical Pharmacology & Therapeutics (2011) 90 2, 328–332. doi:10.1038/clpt.2011.132