A meta-analysis of impact of proton pump inhibitors on antiplatelet effect of clopidogrel.

Previous mechanistic studies have suggested a possible interaction between proton pump inhibitor (PPIs) and clopidogrel. However, the results of clinical trials about the effects of PPIs on safety and efficacy of clopidogrel are controversial. The study sought to estimate the impact of PPIs on antiplatelet effect of clopidogrel. The study performed a meta-analysis of comparative concomitant use of clopidogrel with PPIs versus clopidogrel without PPIs studies published or presented to October 2010. Cardiovascular death, readmission for myocardial infarction/readmission for acute coronary syndrome, and nonfatal stroke were set as clinical endpoints. In randomized control trials (RCTs), the clinical endpoints risk ratio for clopidogrel with PPIs versus clopidogrel without PPIs was 1.20 (P= 0.34) in the random-effects model and 1.03 (P= 0.63) in the fixed-effects model. In observational studies, the risk ratio for the clinical endpoints for clopidogrel with PPI versus clopidogrel without PPI was 1.40 (P < 0.001) in the random-effects model and 1.49 (P < 0.001) in the fixed-effects model. Different assay methods showed that coadministration of clopidogrel with PPIs was associated with attenuation of clopidogrel's antiplatelet effect in vitro. This meta-analysis indicated an obvious discrepancy between RCTs and observational studies with respect to the interaction between PPIs and clopidogrel.