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Enteric Coating as a Factor in Aspirin Resistance

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: NCT00531362
Recruitment Status : Completed
First Posted : September 18, 2007
Last Update Posted : September 29, 2009
Irish Heart Foundation
Information provided by:
Royal College of Surgeons, Ireland

Brief Summary:

Aspirin is an essential drug for the treatment of cardiovascular disease. The standard dose is 75mg per day (much lower than that for inflammation or fever). One of the side-effects of aspirin is a gastric ulcer which can be fatal. To prevent this it is common to use enteric-coated aspirin. This passes through the stomach intact and dissolves in the intestines. This prevents high levels of drug forming in the stomach reducing ulcer formation. Recently there is evidence of high levels of aspirin resistance, ie, patients who appear not to achieve the maximum benefit from aspirin. Clinical studies have shown a significant increase in mortality among these patients.

A recent study that we performed showed that enteric-coated aspirin is not as effective as plain aspirin. This was especially noticeable in heavier volunteers. In fact it appeared that enteric-coated aspirin only delivers 50mg aspirin instead of the full 75 mg. For volunteers resistant to enteric-coated aspirin simply switching them to plain aspirin solved the problem.

We propose to recruit patients on 75 mg enteric aspirin and test them for evidence of poor response to aspirin. Poor responders will then be given 75mg plain aspirin and tested for their response. Those that fail to respond will then receive 150 mg aspirin. If the results of the healthy volunteer study are replicated this would provide a very cheap and effective solution to a serious problem.

Condition or disease Intervention/treatment
Cardiovascular Disease Drug: Plain aspirin

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Study Type : Observational
Actual Enrollment : 250 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Enteric Coating as a Factor in Aspirin Resistance
Study Start Date : September 2007
Actual Primary Completion Date : December 2008
Actual Study Completion Date : December 2008

Resource links provided by the National Library of Medicine

Drug Information available for: Aspirin

Group/Cohort Intervention/treatment
All patients (acute or stable) presenting to a cardiovascular clinic and on aspirin.
Drug: Plain aspirin
Plain aspirin 75 mg or 150 mg

Biospecimen Retention:   Samples Without DNA
Serum samples will be collected and stored for later analysis

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients attending the cardiac outpatients clinic or the cat lab of Beaumont hospital, Dublin, Ireland

Inclusion Criteria:

  • Stable or unstable coronary artery disease
  • On aspirin

Exclusion Criteria:

  • Inability to give informed consent

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): NCT00531362

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Beaumont Hospital
Dublin, Ireland
Sponsors and Collaborators
Royal College of Surgeons, Ireland
Irish Heart Foundation
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Principal Investigator: Dermot Cox, PhD Royal College of Surgeons
Additional Information:
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Responsible Party: Dermot Cox, Royal College of Surgeons in Ireland Identifier: NCT00531362    
Other Study ID Numbers: RCSI1
First Posted: September 18, 2007    Key Record Dates
Last Update Posted: September 29, 2009
Last Verified: September 2009
Keywords provided by Royal College of Surgeons, Ireland:
Acute coronary syndromes
Additional relevant MeSH terms:
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Cardiovascular Diseases
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