PPIs and clopidogrel — Bad combination

Proton pump inhibitors (PPIs) should not be combined with clopidogrel (Plavix^®) based on the results of a study presented at the Society for Cardiovascular Angiography and Interventions (SCAI) in May. PPIs, such as esomeprazole (Nexium^®), omeprazole (Prilosec^®), lansoprazole (Prevacid^®), and pantoprazole (Protonix^®), are frequently prescribed with clopidogrel to prevent GI complications and bleeding. Some guideline groups actually recommend the combination routinely, and as a result more than 50% of people on clopidogrel are currently on a PPI as well. In the study presented to the SCAI, 16,690 patients were evaluated who took clopidogrel for a year after coronary stenting. Patients taking the combination of a PPI and clopidogrel experienced a 50% increase in the combined risk of hospitalization for heart attack, stroke, unstable angina, or repeat revascularization compared to those on clopidogrel alone. The overall rate for combined events was 17.9% for clopidogrel alone, 24.3% for lansoprazole, 24.9% for esomeprazole, 25.1% for omeprazole, and 29.2% for pantoprazole. Patients enrolled in the study took PPIs for an average of 9 months. The SCAI points out that while this is the largest trial to date to examine the interaction between PPIs and clopidogrel, other smaller studies have indicated similar findings. It is theorized that the mechanism is mediated by PPIs blocking the conversion of the prodrug clopdogrel to its active metabolite, which has antiplatelet activity. Currently, SCAI is recommending more research, but in the meantime health care providers who are treating post-stent patients on dual antiplatelet therapy should consider prescribing an H2 blocker, such as ranitidine (Zantac^®), famotidine (Pepcid^®), or cimetidine (Tagamet^®), instead of a PPI. The full statement can be found at www.SCAI.org.