Clopidogrel and Aspirin Interaction Study-2

Study Overview
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Brief Summary
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Clopidogrel and aspirin are commonly used in combination to prevent heart attacks and to prevent blockage of stents. Both clopidogrel and aspirin work by preventing platelets (sticky cells that circulate in the blood) from forming blood clots in the arteries supplying oxygen to the heart and in stents. The investigators hypothesize that aspirin 325mg compared with aspirin 81 mg will increase blood levels of the active metabolite of clopidogrel in patients with a history of coronary artery disease who receive a 600mg loading dose of clopidogrel.

Detailed Description
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Eligible patients will be randomized to receive clopidogrel 600mg + aspirin 325mg (Group A) or clopidogrel 600mg + aspirin 81mg (Group B). Patients will be fasted for at least 8 hours prior to study drug administration. Blood samples will be collected at 1 hour after study drug administration for measurement of clopidogrel active metabolite levels and genotyping.

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

Conditions
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Drug Action Increased

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


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Stable patients >1 month post ACS (including ST elevated myocardial infarction, non-ST elevated myocardial infarction or unstable angina) or stent Receiving regular ASA (81mg/d) and clopidogrel (75mg/d) for at least 1 week Written informed consent Exclusion Criteria: Age < 18 years Liver disease with ALT or bilirubin >2x upper limits of normal (ULN)* Renal impairment with creatinine clearance <30 ml/min* Deemed to be at high risk of bleeding (e.g., recent bleeding, platelet count<100x109/L or hemoglobin <100g/L)* Anticoagulant or NSAID therapy within the last 5 days Antiplatelet agent other than aspirin and clopidogrel within the last 10 days Uncontrolled hypertension (>=180/110mmHg) within 3 months of planned randomization

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: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Higher dose aspirin group<br>Clopidogrel 600 mg plus aspirin 325mg | Drug: Clopidogrel<br>* 600mg (2 pills)<br>* Other names: Plavix;Drug: Aspirin<br>* 325mg (1 pill)<br>* Other names: Novasen;|
| Active Comparator: Low dose aspirin group<br>Clopidogrel 600mg plus aspirin 81mg | Drug: Clopidogrel<br>* 600mg (2 pills)<br>* Other names: Plavix;Drug: Aspirin<br>* 81mg (1 pill)<br>* Other names: Entrophen;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood Concentration of the Active Metabolite of Clopidogrel | Clopidogrel active metabolite concentration will be measured by liquid chromatography tandem mass spectrometry (LC/MS) methods. | 1 hour after loading dose of study medications | 

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