Effect of esomeprazole versus famotidine on platelet inhibition by clopidogrel: a double-blind, randomized trial

Previous studies showed that esomeprazole does not interfere significantly with the platelet inhibitory effect of clopidogrel. It is unknown whether famotidine, a histamine 2 receptor antagonist, interacts with clopidogrel. This double-blind, randomized study aimed to compare the influence of esomeprazole and famotidine on the platelet inhibitory effect of clopidogrel.

Patients with acute coronary syndrome or elective percutaneous coronary interventions treated with aspirin and clopidogrel cotherapy were randomized to receive esomeprazole 20 mg daily or famotidine 40 mg daily. Platelet reactivity units (PRUs) were measured at baseline and on day 28. The primary analysis involved the PRU values on day 28.

There were 44 patients in the esomeprazole group and 44 in the famotidine group. The baseline PRUs of the 2 groups were comparable (esomeprazole vs famotidine, 229.1 ± 85.6 vs 220.4 ± 83.0, P = .63). The PRUs on day 28 were 242.6 ± 89.7 and 237.5 ± 79.2 in the groups receiving esomeprazole and famotidine, respectively (mean difference 5.1, 95% CI -30.8 to 41.0, P = .78).

The platelet inhibitory effect of clopidogrel was not significantly different between patients receiving esomeprazole and those receiving famotidine. Neither esomeprazole nor famotidine reduced the platelet inhibitory effect of clopidogrel. (Clinicaltrial.gov Identifier NCT01062516).