Background and purpose: evidence suggests that some proton pump inhibitors can attenuate the antiplatelet effect of clopidogrel. The significance of this potential drug interaction in patients with cerebrovascular disease is unknown.
Methods: we conducted a nested case-control study of all Ontario residents aged ≥ 66 years newly treated with clopidogrel after a stroke between April 1, 2002, and September 30, 2008. In the primary analysis, case patients were those readmitted for stroke, and a secondary analysis examined all-cause mortality. For each case, up to 4 event-free control subjects were matched on age, gender, and outcome type (stroke or transient ischemic attack). Exposure to proton pump inhibitors was categorized as current (within 60 days), previous (61 to 180 days), or remote (181 to 365 days).
Results: among 2765 patients entering the cohort, we identified 118 cases readmitted for stroke and 472 control subjects. After multivariable adjustment, current use of proton pump inhibitors was not associated with a significantly increased risk of recurrent stroke (adjusted odds ratio, 1.05; 95% CI, 0.60 to 1.82) or death (adjusted odds ratio, 1.84; 95% CI, 0.88 to 3.89).
Conclusions: as a class, proton pump inhibitors are not associated with an increased risk of recurrent stroke or death among older patients treated with clopidogrel after stroke.