PACT (Platelet Activity After Clopidogrel Termination)
Information source: University of Massachusetts
Information obtained from ClinicalTrials.gov on October 19, 2009
Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Blood Platelets; Clopidogrel
Intervention: clopidogrel + aspirin (Drug); placebo + aspirin (Drug)
Phase: N/A
Status: Recruiting
Sponsored by: University of Massachusetts Official(s) and/or principal investigator(s):
Alan D. Michelson, M.D., Principal Investigator, Affiliation: University of Massachusetts Medical School
Overall contact:
Marsha L Fox, MS, RN, Phone: 508-856-0059, Email: fox@platelets.org
Summary
Clopidogrel is a medication that is used to decrease the ability of platelets to form blood
clots.
The theory has been proposed that, in patients with coronary artery disease or stroke,
increased platelet function after discontinuation of clopidogrel therapy is associated with
an increased clotting risk. However, this theory has never been rigorously tested.
The goal of this research is to determine whether discontinuation of clopidogrel results in
increased platelet function.
Clinical Details
Official title: PACT (Platelet Activity After Clopidogrel Termination)
Study design: Basic Science, Randomized, Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Placebo Control, Crossover Assignment, Pharmacodynamics Study
Primary outcome: Platelet reactivity will be measured by low-dose ADP-induced platelet surface activated GPIIb-IIIa complex, as reported by monoclonal antibody PAC1 in a whole blood flow cytometric assay.
Secondary outcome: ADP, TRAP and collagen induced platelet surface activated GPIIb-IIIa, platelet surface P-selectin, and platelet aggregation. Soluble CD40L, P-selectin, and other plasma markers.
Detailed description:
In this study, we will address the question: does discontinuation of clopidogrel result in
platelet hyperreactivity? We will perform a double-blind, placebo-controlled, crossover
study in normal subjects, in whom platelet reactivity will be measured before clopidogrel or
placebo, during clopidogrel or placebo, and at various time points after discontinuation of
clopidogrel or placebo. The dose of clopidogrel will be the standard, FDA-approved dose: 75
mg daily. All subjects will be treated with aspirin 81 mg daily throughout the 57 days of
study assessment in both the clopidogrel arm and the placebo arm, because the clinically
relevant question is: in patients who remain on aspirin, does discontinuation of clopidogrel
result in platelet hyperreactivity?
Eligibility
Minimum age: 21 Years.
Maximum age: 70 Years.
Gender(s): Both.
Criteria:
Inclusion Criteria:
- Must be a normal healthy subject
- Must be between 21-70 years old
- Must be able to take aspirin and clopidogrel.
- Must be able to have blood drawn 16 times over approximately 3 months.
Exclusion Criteria:
- Subject who is currently taking aspirin or another anti-platelet drug such as
clopidogrel. Subject must be free of these medications for 10 days before enrolling
in this study.
- Subject who is currently taking a non-steroidal anti-inflammatory drug such as
ibuprofen or naproxen. Subject must be free of these medications for 3 days before
enrolling in this study.
- Subject who is currently taking medications for depression or medications that lower
blood pressure or lower blood sugar.
- Subject who are pregnant or may become pregnant during the study or who is breast
feeding.
- Subject with a known allergy to aspirin or clopidogrel.
- Cigarette smoking or use of other nicotine product.
- Subject with a history of any of the following: coronary artery disease; stroke;
bleeding disorder; ongoing bleeding; previous life-threatening hemorrhage; stomach
ulcers; gastrointestinal bleeding within the past 1 month; major surgery within the
past 1 month; minor surgery within the past 2 weeks; or platelet transfusion within
the past 7 days.
- Subject with a blood count, measured on the pre-study drug blood sample, that is not
in the normal range.
- Subject who is enrolled in another clinical trial of an investigational drug.
Locations and Contacts
Marsha L Fox, MS, RN, Phone: 508-856-0059, Email: fox@platelets.org
University of Massachusetts Medical School, Worcester, Massachusetts 01655-0002, United States; Recruiting
Marsha L. Fox, MS, RN, Phone: 508-856-0059, Email: fox@platelets.org
Alan D. Michelson, M.D., Principal Investigator
Andrew L. Frelinger, Ph.D., Sub-Investigator
Additional Information
Home page of the study principal investigator
Starting date: April 2008
Ending date: July 2009
Last updated: February 20, 2009
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