Reproducibility and Comparison of Platelet Function Assays With Aspirin and Clopidogrel (MK-0000-167)

Study Overview
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Brief Summary
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This study will evaluate whether the antiplatelet effects of Aspirin 300 mg daily and Clopidogrel 75 mg daily can be reproducibly measured using several point of care platelet function assays

Official Title
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A Randomized, Double-Blind, Placebo-Controlled, Cross-over Study Using Aspirin and Clopidogrel to Assess Reproducibility and Compare Platelet Function Assays

Conditions
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Healthy Volunteers

Intervention / Treatment
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* Drug: Placebo (to match Aspirin)
* Drug: Aspirin
* Drug: Clopidogrel
* Drug: Comparator: Placebo (to match Clopidogrel)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject has BMI (Body Mass Index) less than 32 kg/m^ 2 Subject has been a nonsmoker and/or has not used nicotine or nicotine-containing products for at least approximately 3 months Subject does not have a history of any bleeding disorder Exclusion Criteria: Subject is a pregnant or nursing female Subject has a history of multiple and/or severe allergies to drugs or foods, or any history (personal or family) of bleeding disorders (including arterial bleeding, hemorrhage requiring transfusion or urgent intervention) Subject currently uses on a regular basis or has used aspirin or clopidogrel within 21 days prior to screening (including low-dose aspirin and pain relievers, cold, or sinus remedies containing aspirin) Subject currently uses on a regular basis or has used within 2 weeks prior to study start, any other prescription or nonprescription drugs, including NSAIDs such as ibuprofen, naproxen, COX-II inhibitors such as celecoxib or etoricoxib, other pain relievers, cold, or sinus remedies containing NSAIDs, and herbal remedies (e.g., St. John Wort) Subject anticipates needing during the study any prescription or nonprescription (including over the counter) preparation, including those that contain aspirin, ibuprofen, or any other NSAID or NSAID-containing product commonly found in pain relievers, cold or sinus remedies Subject has a history of skin conditions (such as dry skin, pruritus, rosacea, eczema) or has a sun burn at the time of screening and is unwilling to avoid excessive sun exposure for the duration of the study Subject regularly uses antacids or other OTC medications (4 or more times per month) for symptoms of dyspepsia or has a history of use of prescription ulcer medication such as H2 blockers (e.g., cimetidine, ranitidine, famotidine, nizatidine) or a proton pump inhibitor (omeprazole) within the last 5 years Subject has a history of poor wound healing or a tendency to form keloids

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sequence 1<br>Aspirin - Clopidogrel - Placebo | Drug: Placebo (to match Aspirin)<br>* Placebo grossly matched Aspirin 300 mg daily<br>Drug: Aspirin<br>* Aspirin 300 mg daily<br>Drug: Clopidogrel<br>* Clopidogrel 75 mg daily<br>Drug: Comparator: Placebo (to match Clopidogrel)<br>* Placebo (grossly matched Clopidogrel 75 mg) daily<br>|
| Experimental: Sequence 2<br>Clopidogrel - Placebo - Aspirin | Drug: Placebo (to match Aspirin)<br>* Placebo grossly matched Aspirin 300 mg daily<br>Drug: Aspirin<br>* Aspirin 300 mg daily<br>Drug: Clopidogrel<br>* Clopidogrel 75 mg daily<br>Drug: Comparator: Placebo (to match Clopidogrel)<br>* Placebo (grossly matched Clopidogrel 75 mg) daily<br>|
| Experimental: Sequence 3<br>Placebo - Aspirin - Clopidogrel | Drug: Placebo (to match Aspirin)<br>* Placebo grossly matched Aspirin 300 mg daily<br>Drug: Aspirin<br>* Aspirin 300 mg daily<br>Drug: Clopidogrel<br>* Clopidogrel 75 mg daily<br>Drug: Comparator: Placebo (to match Clopidogrel)<br>* Placebo (grossly matched Clopidogrel 75 mg) daily<br>|
| Experimental: Sequence 4<br>Aspirin - Placebo - Clopidogrel | Drug: Placebo (to match Aspirin)<br>* Placebo grossly matched Aspirin 300 mg daily<br>Drug: Aspirin<br>* Aspirin 300 mg daily<br>Drug: Clopidogrel<br>* Clopidogrel 75 mg daily<br>Drug: Comparator: Placebo (to match Clopidogrel)<br>* Placebo (grossly matched Clopidogrel 75 mg) daily<br>|
| Experimental: Sequence 5<br>Clopidogrel - Aspirin - Placebo | Drug: Placebo (to match Aspirin)<br>* Placebo grossly matched Aspirin 300 mg daily<br>Drug: Aspirin<br>* Aspirin 300 mg daily<br>Drug: Clopidogrel<br>* Clopidogrel 75 mg daily<br>Drug: Comparator: Placebo (to match Clopidogrel)<br>* Placebo (grossly matched Clopidogrel 75 mg) daily<br>|
| Experimental: Sequence 6<br>Placebo - Clopidogrel - Aspirin | Drug: Placebo (to match Aspirin)<br>* Placebo grossly matched Aspirin 300 mg daily<br>Drug: Aspirin<br>* Aspirin 300 mg daily<br>Drug: Clopidogrel<br>* Clopidogrel 75 mg daily<br>Drug: Comparator: Placebo (to match Clopidogrel)<br>* Placebo (grossly matched Clopidogrel 75 mg) daily<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The effect size of light transmission platelet aggregation, bleeding time, and several point of care platelet function assays after 3 days of administration of study drug compared to placebo treatment. |  | Baseline and 3 days | 
| The intra-subject coefficient of variation of each of the 3 platelet function devices |  | Baseline and 3 days |