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Clopidogrel/Aspirin Interaction Study (INTERACTION)

This study has been completed.
Information provided by (Responsible Party):
John Eikelboom, Population Health Research Institute Identifier:
First received: April 8, 2010
Last updated: April 27, 2015
Last verified: April 2015
This study will explore the effect of different doses of aspirin on the effects of double-dose or standard dose clopidogrel.

Condition Intervention Phase
Coronary Artery Disease
Drug: Clopidogrel
Drug: Aspirin
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Randomized, Factorial Study 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 Population Health Research Institute:

Primary Outcome Measures:
  • Blood concentrations of the active metabolite of clopidogrel [ Time Frame: 14 days ]

Secondary Outcome Measures:
  • Inhibition of adenosine diphosphate (ADP) induced platelet aggregation [ Time Frame: 14 days ]

Enrollment: 82
Study Start Date: April 2010
Study Completion Date: February 2013
Primary Completion Date: December 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Standard dose clopidogrel
300 mg Loading x 1 day, 75 mg/d x 13 days
Drug: Clopidogrel
300 mg loading dose, then 75 mg daily
Other Name: Plavix
Experimental: Double dose clopidogrel
600 mg Loading x 1 day, 150 mg/d x 6 days, 75 mg/d x 7 days
Drug: Clopidogrel
600 mg loading dose, 150 mg daily day 2-7, then 75 mg daily
Other Name: Plavix
Active Comparator: Standard dose aspirin
Aspirin 81mg/d x 14 days
Drug: Aspirin
81 mg daily
Other Name: Entrophen
Experimental: High dose aspirin
Aspirin 325 mg/d x 14 days
Drug: Aspirin
325 mg daily
Other Name: Novasen

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.

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

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01102439

Canada, Ontario
Population Health Research Institute
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

Responsible Party: John Eikelboom, MD., Population Health Research Institute Identifier: NCT01102439     History of Changes
Other Study ID Numbers: 10-082
Study First Received: April 8, 2010
Last Updated: April 27, 2015

Keywords provided by Population Health Research Institute:

Additional relevant MeSH terms:
Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Heart Diseases
Cardiovascular Diseases
Arterial Occlusive Diseases
Vascular Diseases
Platelet Aggregation Inhibitors
Purinergic P2Y Receptor Antagonists
Purinergic P2 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Fibrinolytic Agents
Fibrin Modulating Agents
Cytochrome P-450 CYP2C19 Inhibitors
Cytochrome P-450 Enzyme Inhibitors
Enzyme Inhibitors
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Anti-Inflammatory Agents processed this record on March 29, 2017