Clopidogrel/Aspirin Interaction Study

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

Status

Completed

Phases

Phase 4

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01102439

Acronym

INTERACTION

Enrollment

Registered

2010-04-13

Start date

2010-04-30

Completion date

2013-02-28

Last updated

2015-04-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Coronary Artery Disease

Keywords

Clopidogrel, Aspirin, Interaction

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.

Interventions

DRUGAspirin

81 mg daily

DRUGClopidogrel

300 mg loading dose, then 75 mg daily

Study design

Allocation

RANDOMIZED

Intervention model

FACTORIAL

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

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

Design outcomes

Primary

Measure	Time frame
Blood concentrations of the active metabolite of clopidogrel	14 days

Secondary

Measure	Time frame
Inhibition of adenosine diphosphate (ADP) induced platelet aggregation	14 days

Countries

Canada

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026