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Clopidogrel and Aspirin Interaction Study-2 (Interaction2)

This study has been completed.
Information provided by (Responsible Party):
John Eikelboom, Population Health Research Institute Identifier:
First received: April 25, 2011
Last updated: April 27, 2015
Last verified: April 2015
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.

Condition Intervention Phase
Drug Action Increased Drug: Clopidogrel Drug: Aspirin Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Randomized Controlled Trial to Explore Interaction Between Aspirin and Clopidogrel in Stable Patients With Previous Myocardial Infarction or Coronary Artery Stent

Resource links provided by NLM:

Further study details as provided by John Eikelboom, Population Health Research Institute:

Primary Outcome Measures:
  • Blood concentration of the active metabolite of clopidogrel [ Time Frame: 1 hour after loading dose of study medications ]
    Clopidogrel active metabolite concentration will be measured by liquid chromatography tandem mass spectrometry (LC/MS) methods.

Enrollment: 220
Study Start Date: May 2011
Study Completion Date: April 2013
Primary Completion Date: April 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Higher dose aspirin group
Clopidogrel 600 mg plus aspirin 325mg
Drug: Clopidogrel
600mg (2 pills)
Other Name: Plavix
Drug: Aspirin
325mg (1 pill)
Other Name: Novasen
Active Comparator: Low dose aspirin group
Clopidogrel 600mg plus aspirin 81mg
Drug: Clopidogrel
600mg (2 pills)
Other Name: Plavix
Drug: Aspirin
81mg (1 pill)
Other Name: Entrophen

Detailed Description:
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.

Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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
  Contacts and Locations
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Please refer to this study by its identifier: NCT01341964

Canada, Ontario
Population Health Research Institute, Hamilton General Hospital
Hamilton, Ontario, Canada, L8L 2X2
Sponsors and Collaborators
Population Health Research Institute
Principal Investigator: Yan Liang, MD Population Health Research Institute
Study Director: John Eikelboom, MD Population Health Research Institute
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: John Eikelboom, Dr, Population Health Research Institute Identifier: NCT01341964     History of Changes
Other Study ID Numbers: 11-090
Study First Received: April 25, 2011
Last Updated: April 27, 2015

Keywords provided by John Eikelboom, Population Health Research Institute:

Additional relevant MeSH terms:
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Inflammatory Agents
Antirheumatic Agents
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Platelet Aggregation Inhibitors
Cyclooxygenase Inhibitors
Enzyme Inhibitors
Purinergic P2Y Receptor Antagonists
Purinergic P2 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents
Cytochrome P-450 CYP2C19 Inhibitors
Cytochrome P-450 Enzyme Inhibitors processed this record on September 21, 2017