Clopidogrel/Aspirin Interaction Study

Study Overview
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Brief Summary
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This study will explore the effect of different doses of aspirin on the effects of double-dose or standard dose clopidogrel.

Detailed Description
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Study Hypothesis: Patients receiving double-dose compared with standard-dose clopidogrel will have increased blood concentrations of the active metabolite of clopidogrel and greater inhibition of ADP-induced platelet aggregation when also treated with acetylsalicylic acid (ASA) 325 mg/d as compared to ASA 81 mg/d.

Official Title
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Randomized, Factorial Study to Explore Interaction Between Aspirin and Clopidogrel in Stable Patients With Previous Myocardial Infarction or Coronary Artery Stent

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Drug: Clopidogrel
* Drug: Clopidogrel
* Drug: Aspirin
* Drug: Aspirin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: > 1 month post myocardial infarction (MI), unstable angina or stent patients with stable condition Receiving regular ASA (81mg/d) and clopidogrel (75mg/d) for at least 1 week Written informed consent Exclusion Criteria: Age < 18 years old Liver disease with transaminases and/or bilirubin > 1.5x upper limits of normal (ULN) (within 3 months of randomization) Renal impairment with creatinine clearance < 30 ml/min (within 3 months of randomization) Platelet count < 100x109/L and/or Hb< 100g/L (within 3 months of randomization) Use of oral anticoagulants or nonsteroidal antiinflammatory drug (NSAID) within the last 10 days or planned use during the study Use of antiplatelet agent other than aspirin and clopidogrel within the last 10 days High risk of bleeding (e.g. recent gastrointestinal bleeding, bleeding diathesis) Uncontrolled hypertension (> 180/110mmHg) Current smoker with ≥ 5 cigarettes/day Previously entered in this study or just finished other study within 2 weeks before recruitment Medical, geographic, or social factors making study participation impractical, or inability to provide written informed consent

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Standard dose clopidogrel<br>300 mg Loading x 1 day, 75 mg/d x 13 days | Drug: Clopidogrel<br>* 300 mg loading dose, then 75 mg daily<br>* Other names: Plavix;|
| Experimental: Double dose clopidogrel<br>600 mg Loading x 1 day, 150 mg/d x 6 days, 75 mg/d x 7 days | Drug: Clopidogrel<br>* 600 mg loading dose, 150 mg daily day 2-7, then 75 mg daily<br>* Other names: Plavix;|
| Active Comparator: Standard dose aspirin<br>Aspirin 81mg/d x 14 days | Drug: Aspirin<br>* 81 mg daily<br>* Other names: Entrophen;|
| Experimental: High dose aspirin<br>Aspirin 325 mg/d x 14 days | Drug: Aspirin<br>* 325 mg daily<br>* Other names: Novasen;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood concentrations of the active metabolite of clopidogrel |  | 14 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Inhibition of adenosine diphosphate (ADP) induced platelet aggregation |  | 14 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Clopidogrel, Aspirin, Interaction