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Mechanism Based Resistance to Aspirin

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00948987
Recruitment Status : Completed
First Posted : July 30, 2009
Last Update Posted : October 15, 2009
National Institutes of Health (NIH)
Information provided by:
University of Pennsylvania

Brief Summary:
The purpose of this research is to study why some people do not respond to the benefits of aspirin therapy. The benefit of aspirin is cardioprotection, or decreasing the risk of heart attack and/or stroke. Aspirin works by disabling the platelets, part of the blood cells used in clotting, from sticking together and forming blood clots, thus protecting the heart. It has been observed that failure to respond to aspirin therapy occurs in about 10% of the general population and that despite taking aspirin everyday, this group of non- responders is not getting protection for their heart. The investigators would like to determine why and how this happens.

Condition or disease Intervention/treatment Phase
Aspirin Resistance Pharmacological Aspirin Non-responsiveness Drug: Aspirin Phase 1

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 400 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Mechanism Based Resistance to Aspirin
Study Start Date : September 2004
Actual Primary Completion Date : October 2009
Actual Study Completion Date : October 2009

Resource links provided by the National Library of Medicine

Drug Information available for: Aspirin

Arm Intervention/treatment
Experimental: Aspirin
single dose of aspirin 325 mg p.o.
Drug: Aspirin
325 mg enteric coated single dose p.o.

Primary Outcome Measures :
  1. Arachidonic acid induced platelet aggregation [ Time Frame: 8 hours postdose ]

Secondary Outcome Measures :
  1. Serum thromboxane B2 concentration Urinary 11-dehydro thromboxane B2 concentration Urinary 2,3 dinor-6 keto PGF1α concentration [ Time Frame: 8 hours postdose ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age between 18 - 55
  • Subjects must be in good health as based on medical history, physical examination, vital signs, and laboratory tests.
  • All subjects must be non- smoking volunteers
  • Female subjects of child bearing potential must be using a medically acceptable method of contraception (oral contraception, depo-provera injection, IUD, condom with spermicide, diaphragm, cervical cap, progestin implant, abstinence, tubal ligation, oophorectomy, TAH) throughout the entire study period. All female subjects must consent to a urine pregnancy test at screening and just prior to the start of each treatment phase of the study, which must be negative at all time points.
  • Subjects must be within 30% of their ideal body weight.

Exclusion Criteria:

  • Female subjects who are pregnant or nursing a child.
  • Subjects, who have received an experimental drug, used an experimental medical device within 30 days prior to screening, or who gave a blood donation of ≥ one pint within 8 weeks prior to screening.
  • Subjects with any coagulation, bleeding or blood disorders.
  • Subjects who are sensitive or allergic to aspirin as well as any of their components.
  • Subjects with documented history of any gastrointestinal disorders, including bleeding ulcers.
  • Subjects with any evidence of cancer.
  • Subjects with a history of heart disease, including myocardial infarction, angina, coronary artery disease, any evidence of coronary artery stenosis, arrhythmias, heart failure, having had a CABG
  • Subjects with renal, hepatic, respiratory, endocrine, metabolic, hematopoietic or neurological disorder.
  • Subjects with any abnormal laboratory value or physical finding that according to the investigator may interfere with interpretation of the study results, be indicative of an underlying disease state, or compromise the safety of a potential subject.
  • Subjects who have had a history of drug or alcohol abuse within the last 6 months.

Information from the National Library of Medicine

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 identifier (NCT number): NCT00948987

Sponsors and Collaborators
University of Pennsylvania
National Institutes of Health (NIH)
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Principal Investigator: Garret A FitzGerald, MD University of Pennsylvania, Institute for Translationals Medicine and Therapeutics
Principal Investigator: Susanne Fries, MD University of Pennsylvania, Institute for Translationals Medicine and Therapeutics
Principal Investigator: Tilo Grosser, MD University of Pennsylvania, Institute for Translationals Medicine and Therapeutics
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Garret A. FitzGerald, University of Pennsylvania Identifier: NCT00948987    
Other Study ID Numbers: 801907
First Posted: July 30, 2009    Key Record Dates
Last Update Posted: October 15, 2009
Last Verified: October 2009
Keywords provided by University of Pennsylvania:
aspirin resistance
cardiovascular risk
platelet inhibition
Additional relevant MeSH terms:
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Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Inflammatory Agents
Antirheumatic Agents
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Platelet Aggregation Inhibitors
Cyclooxygenase Inhibitors
Enzyme Inhibitors