TABLE 3.

FDA-boxed warning on clopidogrel (Plavix) product label

WARNING: DIMINISHED EFFECTIVENESS IN POOR METABOLIZERS
• Effectiveness of Plavix depends on activation to an active metabolite by the cytochrome P450 (CYP) system, principally CYP2C19.
• Poor metabolizers treated with Plavix at recommended doses exhibit higher cardiovascular event rates after acute coronary syndrome (ACS) or percutaneous coronary intervention (PCI) than patients with normal CYP2C19 function.
• Tests are available to identify a patient's CYP2C19 genotype and can be used as an aid in determining therapeutic strategy.
• Consider alternative treatment or treatment strategies in patients identified as CYP2C19 poor metabolizers.