Modified-release Dipyridamole/Aspirin (200mg/25mg bd) Versus Aspirin (75mg) in Aspirin-resistant Patients

Study Overview
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Brief Summary
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The primary objective of this study is to assess whether adding modified-release dipyridamole to aspirin (Asasantin Retard) has measurable effects on markers of platelet function (for example, platelet aggregation) in patients with cardiovascular disease who are known to be resistant to aspirin alone

Official Title
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A Randomised, Crossover Study Comparing the Biochemical and Platelet Effects of Modified-release Dipyridamole/Aspirin (200mg/25 mg bd; Asasantin Retard®) With Aspirin (75 mg qd) in Coronary Artery Disease Patients With Aspirin Resistance Manifesting as Persistent Thromboxane Formation.

Conditions
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Coronary Arteriosclerosis

Intervention / Treatment
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* Drug: modified-release dipyridamole/aspirin
* Drug: aspirin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Cardiovascular disease (including history of stroke or transient ischaemic attack) Documented evidence of resistance to aspirin Capable of comprehending and communicating effectively with the investigator and staff and of providing informed consent. Willing to give informed consent prior to participation in the trial. Exclusion Criteria: Any clinically significant condition other than cardiovascular disease. Clinically significant abnormal baseline haematology, blood chemistry or urinalysis findings. Use of dipyridamole, clopidogrel, ticlopidine or any non-steroidal anti-inflammatory agent (NSAID)(including COX-2 inhibitors) during the two weeks before randomisation and during the trial. Active peptic ulceration or history of peptic ulcer disease. Known history of or suspected hypersensitivity to dipyridamole, aspirin, any NSAID or any other component of the test drugs. History of any bleeding disorder. History of cerebral haemorrhage. Resting seated blood pressure less than 90/60mmHg. Participation in any drug clinical trial within sixteen weeks prior to the start of the trial. Any indication of current or previous abuse of alcohol, solvents or drugs. Asthma. Pregnant or nursing women or women of childbearing potential not using a medically approved means of contraception (e.g. oral contraceptives, intrauterine devices or surgically sterile). Previous participation in the randomisation phase of this clinical trial.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment


Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: modified-release dipyridamole/aspirin|nan|
|Drug: aspirin|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| platelet aggregation in response to arachidonic acid |  | baseline, day 14, day 30 of each period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| platelet aggregation in response to epinephrine, adenosine diphosphate (ADP) and collagen |  | baseline, day 14, day 30 of each period | 
| serum thromboxane B2 |  | baseline, day 14, day 30 of each period | 
| urinary 2,3,-dinor-6-keto-prostaglandin F1α |  | baseline, day 30 of each period | 
| urinary 11-dehydro-thromboxane B2 |  | baseline, day 30 of each period | 
| plasma CD40L |  | baseline, day 14, day 30 of each period | 
| flow cytometry measurements of platelet receptors in blood samples |  | baseline, day 14, day 30 of each period | 
| bleeding time |  | day 30 of each period | 
| 6-keto-prostaglandin F1α (in bleeding time samples) |  | day 30 of each period | 
| thromboxane B2 (in bleeding time samples) |  | day 30 of each period | 
| flow cytometry measurements from bleeding time samples |  | day 30 of each period] | 
| coagulation markers F1.2 and fibrinopeptide A (in bleeding time samples) |  | day 30 of each period | 
| pulse rate and blood pressure |  | baseline, day 14, day 30 of each period |