Platelet Inhibitory Effect of Clopidogrel in Patients Treated With Omeprazole, Pantoprazole, or Famotidine

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.

Conditions

• Coronary Heart Disease
• GI Bleeding

Interventions

DRUG

omeprazole, 20mg twice daily

Each patient will undergo 3 phases of drug therapy: A- 4 weeks of PPI treatment (omeprazole, 20mg twice daily)) B- 4 weeks of H2 blocker treatment (famotidine 40mg twice daily) C- 4 weeks of PPI treatment (pantoprazole 40mg once daily). At the end of each phase- each patient will undergo the following evaluation: Platelet reactivity

DRUG

famotidine 40mg twice daily

Each patient will undergo 3 phases of drug therapy: A- 4 weeks of PPI treatment (omeprazole, 20mg twice daily)) B- 4 weeks of H2 blocker treatment (famotidine 40mg twice daily) C- 4 weeks of PPI treatment (pantoprazole 40mg once daily). At the end of each phase- each patient will undergo the following evaluation: Platelet reactivity

DRUG

pantoprazole 40mg once daily

Each patient will undergo 3 phases of drug therapy: A- 4 weeks of PPI treatment (omeprazole, 20mg twice daily)) B- 4 weeks of H2 blocker treatment (famotidine 40mg twice daily) C- 4 weeks of PPI treatment (pantoprazole 40mg once daily). At the end of each phase- each patient will undergo the following evaluation: Platelet reactivity

Sponsors & Collaborators

• Tel Aviv Medical Center

  collaborator OTHER

• Tel-Aviv Sourasky Medical Center

  lead OTHER_GOV

Principal Investigators

• Shmuel Banai, MD · Tel Aviv Medical Center, Israel

Study Design

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2009-08-31

Primary Completion

2011-06-30

Completion

2011-08-31

Countries

• Israel

Study Locations