Influence Of Omeprazole On The Anti-Platelet Action Of Clopidogrel
Condition: Coronary Heart Disease
MeSH terms: Heart Diseases; Coronary Disease; Coronary Artery Disease; Myocardial Ischemia
Study type: Interventional
Phase: Phase 3

Summary: 
      Objectives: A prospective investigation of the effect of omeprazole, a proton pump inhibitor,
      on the anti-platelet action of clopidogrel.

      The main decision criterion will concern change in VASP protein phosphorylation under
      treatment. Phosphorylation will be measured before and after administration of omeprazole
      versus placebo in patients undergoing clopidogrel treatment.

      Type of study: Single center, double blind, randomized parallel group study versus placebo,
      comparing two treatment groups:

        -  clopidogrel + omeprazole + standard regime (beta-blockers, atorvastatin, IEC, aspirin)

        -  clopidogrel + placebo+ standard regime (beta-blockers, atorvastatin, IEC, aspirin)

      Study population: 120 patients from the Cardiology Department of Brest University hospital,
      Brest (France), receiving a standard treatment comprising a loading dose of clopidogrel
      followed by a daily dose of 75 mg associated to 75 mg aspirin, will be randomized between 20
      mg/day omeprazole and 20 mg/day placebo treatment groups. The efficacy of clopidogrel will be
      assessed by inter-group comparison on the VASP test.

      Study period: 7 days' treatment per patient. Total study period estimated at 6 months.

      Expected findings: The results should confirm the suspected negative effect of omeprazole on
      clopidogrel's impact on arterial thrombosis risk, secondarily allowing new recommendations to
      be drawn up for this association.
    

Detailed description: 
      Preventing recurrence of thrombosis following angioplasty relies on dual-therapy associating
      the anti-platelet agents aspirin and clopidogrel. This regime is kept up for between 1 and 6
      months, depending on the type of stent deployed in the angioplasty. The biological
      effectiveness of the clopidogrel treatment can be assessed by the VASP test, a new platelet
      test, results on which have been shown to correlate with risk of thrombosis. A study we ran
      recently strongly suggested that omeprazole was associated with a poor response to
      clopidogrel. Omeprazole is an anti-ulcer agent frequently prescribed to prevent unwanted
      side-effects of aspirin, making it frequently associated to clopidogrel in the aftermath of
      angioplasty.

      Study population: 120 patients from the Cardiology Department of Brest University hospital,
      Brest (France), receiving a standard treatment comprising a loading dose of clopidogrel
      followed by a daily dose of 75 mg associated to 75 mg aspirin, will be randomized between 20
      mg/day omeprazole and 20 mg/day placebo treatment groups. The efficacy of clopidogrel will be
      assessed by inter-group comparison on the VASP test.

      Study period: 7 days' treatment per patient. Total study period estimated at 6 months.
    

Intervention name(s): impact on VASP test
Intervention type(s): Drug
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double
Primary purpose: Treatment
Keywords: clopidogrel; omeprazole