Clopidogrel/Aspirin Interaction Study

Phase 4

Completed

• Conditions: Coronary Artery Disease
• Interventions: Drug: Clopidogrel; Drug: Aspirin

• Registration Number: NCT01102439
• Lead Sponsor: Population Health Research Institute

Brief Summary

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

Detailed Description

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.

Study Timeline

• Study Start: 2010-04
• Study First Submitted: 2010-04-08
• Study First Submitted QC: 2010-04-12
• Study First Posted: 2010-04-13
• Primary Completion: 2010-12
• Study Completion: 2013-02
• Status Verified: 2015-04
• Last Update Submitted: 2015-04-27
• Last Update Posted: 2015-04-28

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 82

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: FACTORIAL

Arm && Interventions

Group	Intervention	Description
Standard dose clopidogrel	Clopidogrel	300 mg Loading x 1 day, 75 mg/d x 13 days
Double dose clopidogrel	Clopidogrel	600 mg Loading x 1 day, 150 mg/d x 6 days, 75 mg/d x 7 days
Standard dose aspirin	Aspirin	Aspirin 81mg/d x 14 days
High dose aspirin	Aspirin	Aspirin 325 mg/d x 14 days

Primary Outcome Measures

Name	Time	Method
Blood concentrations of the active metabolite of clopidogrel	14 days

Secondary Outcome Measures

Name	Time	Method
Inhibition of adenosine diphosphate (ADP) induced platelet aggregation	14 days

Trial Locations

Locations (1)

Population Health Research Institute; 🇨🇦 Hamilton, Ontario, Canada