A while back I reviewed the literature on the interaction between clopidogrel and statins, particularly atorvastatin. Although there were conflicting opinions the prevailing consensus was that the drugs could safely be used in combination. Now comes this study published in the American Heart Journal suggesting that the interaction is clinically significant. This retrospective study using administrative databases from Quebec was restricted to patients prescribed clopidogrel after undergoing coronary stenting. Patients receiving atorvastatin had an increase (!) in a composite outcome for vascular events at 30 days (adjusted OR 1.65, 95% CI 1.07-2.54). A delay in getting the clopidogrel prescription filled was also significantly associated with increased events.
The authors, acknowledging weaknesses in this study, were cautious in their conclusions and called for further studies, but this really concerns me. My take home messages are 1) in the early months following coronary stenting consider using a statin that is not a substrate for CYP3A4 and 2) upon discharge after coronary stenting send your patient straight to the drug store and consider dispensing a couple of clopidogrel tablets!