Validation of an Assay to Measure Cyclooxygenase-1 Activity
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|ClinicalTrials.gov Identifier: NCT00761891|
Recruitment Status : Completed
First Posted : September 30, 2008
Results First Posted : April 18, 2019
Last Update Posted : April 18, 2019
|Condition or disease||Intervention/treatment||Phase|
|Healthy||Other: Chewable aspirin||Not Applicable|
Aspirin has been shown to reduce cardiovascular events in at-risk individuals, but some aspirin-treated patients fail to exhibit expected changes in bleeding time and platelet aggregation. Recent evidence has correlated aspirin "non-response" to poor cardiovascular outcomes.
In order to study the mechanisms of aspirin resistance, an assay is needed to measure the catalytic activity of platelet cyclooxygenase (which should be inhibited by aspirin). A common assay in general use is the measurement of thromboxane B2 production in clotting whole blood. This measure, however, is influenced by genetic and environmental variations in the glass-activated coagulation pathway, albumin binding capacity, platelet activation pathways, arachidonic acid pools, and phospholipase activity.
Our laboratory has developed a direct assay of platelet cyclooxygenase (COX-1) activity that is not influenced by these variations. This study will generate a reference range in normal volunteers taking a routine clinical dose of aspirin (81mg daily) for this assay.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||64 participants|
|Intervention Model:||Single Group Assignment|
|Masking:||None (Open Label)|
|Official Title:||Validation of an Ex Vivo Cyclooxygenase-1 Catalytic Assay in Humans|
|Study Start Date :||May 2007|
|Actual Primary Completion Date :||May 2008|
|Actual Study Completion Date :||January 2010|
Experimental: Chewable aspirin
81 mg daily for 2 weeks
Other: Chewable aspirin
chewable aspirin 81mg daily for 2 weeks
Other Name: acetylsalicylic acid
- A Reference Range in Normal Volunteers Taking a Routine Clinical Dose of Aspirin (81mg Daily) for 2 Weeks [ Time Frame: 2 weeks ]
Determine the level of Thromboxane B2 at which patients with a result above are not fully inhibited, and patients with a TxB2 level below are fully inhibited.
The reference range is the level of serum thromboxane at which participants below have fully inhibited COX-1 and participants above do not have fully inhibited COX-1 activity
- Serum Thromboxane [ Time Frame: Baseline and at 2 weeks ]SerumTxB2: They are formed from the prostaglandin endoperoxides and cause platelet aggregation, contraction of arteries, and other biological effects.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00761891
|United States, Tennessee|
|Nashville, Tennessee, United States, 37232|
|Principal Investigator:||John A Oates, MD||Vanderbilt University|