Statin–Clopidogrel Interactions: Are They Clinically Important?

Clopidogrel and some statins — including simvastatin, atorvastatin, and lovastatin — are metabolized through the liver’s CYP3A4 enzyme system, raising the possibility of drug–drug interactions. Some prior, mostly ex vivo, experiments have suggested that statins may diminish clopidogrel’s efficacy, but is there evidence of a clinically significant effect?

In this post hoc analysis of a randomized trial of clopidogrel in patients with either known cardiovascular disease or multiple risk factors (the CHARISMA trial; Journal Watch Mar 21 2006), investigators studied more than 15,000 patients; approximately two thirds were receiving statins at baseline. In the overall study, the primary endpoint of myocardial infarction, stroke, or cardiovascular…