Platelet Inhibitory Effect of Clopidogrel in Patients Treated With Omeprazole, Pantoprazole, or Famotidine
Status:
Completed
Trial end date:
2011-08-01
Target enrollment:
Participant gender:
Summary
Current guidelines recommend the addition of proton pump inhibitors (PPI) to patients taking
double anti-platelet therapy (Aspirin and Clopidogrel) to prevent upper GI bleeding1. Many
post percutaneous coronary intervention (PCI) patients are treated with dual anti-platelet
medications as well as PPI to prevent upper GI bleeding.
Recently, it was shown that PPI interact with the P450 system in the liver and reduce the
platelet inhibitory effect of Clopidogrel2,3. Clopidogrel is activated by CYP2C19, which also
metabolizes PPI4. Furthermore, a recent article showed increased mortality in patients taking
PPI and clopidogrel compared with patients taking clopidogrel without PPI protection5. The
degree of reduction in the platelet inhibitory properties of clopidogrel might vary among the
different PPI4.
The use of PPI for GI protection in patients treated with dual anti-platelet therapy is not
based on randomized trials, but rather on expert opinion. Since H2 blockers are also
effective in preventing acid secretion and are not known to interact with the P450 system
that affects clopidogrel, the investigators hypothesized that these group of drugs will not
interfere with the positive antiplatelet effects of clopidogrel and therefore will offer a
good alternative treatment option.