Clopidogrel, a drug used to reduce the risk of serious cardiac events, may be ineffective for a subgroup of patients who do not metabolize the drug effectively, according to a warning from the US Food and Drug Administration (FDA).
Individuals with certain variants of the gene encoding the CYP2C19 enzyme are unable to efficiently convert clopidogrel into its active form and may not receive the anticlotting benefits of the drug, which is used to reduce the risk of myocardial infarction, unstable angina, stroke, and death related to cardiovascular disease. The FDA estimates that 2% to 14% of the population carry such variants.
Kuehn BM. Clopidogrel Warning. JAMA. 2010;303(16):1587. doi:10.1001/jama.2010.459