Plavix (clopidogrel bisulfate) 75 mg tablet
Detailed View: Safety Labeling Changes Approved By FDA Center for Drug Evaluation and Research (CDER) – November 2009
Reduced effectiveness due to impaired CYP2C19 function
- The inhibition of platelet aggregation by clopidogrel is entirely due to an active metabolite. Clopidogrel is metabolized to this active metabolite in part by CYP2C19. This metabolism can be impaired by genetic variations in CYP2C19 and by concomitant medications that interfere with CYP2C19. Avoid use of Plavix in patients with impaired CYP2C19 function due to known genetic variation or due to drugs that inhibit CYP2C19 activity.
- Genetic variations: Patients with genetically reduced CYP2C19 function have diminished antiplatelet responses and generally exhibit higher cardiovascular event rates following myocardial infarction than do patients with normal CYP2C19 function.
- Drug interactions: Co-administration of Plavix with omeprazole, a proton pump inhibitor that is an inhibitor of CYP2C19, reduces the pharmacological activity of Plavix if given concomitantly or if given 12 hours apart. There is no evidence that other drugs that reduce stomach acid, such as most H2 blockers (except cimetidine, which is a CYP2C19 inhibitor) or antacids interfere with the antiplatelet activity of clopidogrel.
Information for Patients
- subsection was reworded and reordered
- Omeprazole: In a crossover clinical study, 72 healthy subjects were administered Plavix (300-mg loading dose followed by 75 mg/day) alone and with omeprazole (80 mg at the same time as Plavix) for 5 days...