Aspirin resistance: Vascular diseases are common problems and aspirin is used as an anti-platelet drug to prevent thrombosis. However, aspirin's anti-platelet effect may not be uniform in all patients. From a biochemical perspective, aspirin resistance refers to patients who do not display an adequate degree of platelet inhibition on formal laboratory tests. Published data suggest that 5 - 45% of patients are 'aspirin resistant'. The mechanisms of aspirin resistance are poorly understood.
Conditions
Interventions
Product Name: Aspirin
Product Code: Aspirin
Pharmaceutical Form: Orodispersible tablet
Pharmaceutical form of the placebo: Orodispersible tablet
Route of administration of the placebo: Oral use
Produ
Sponsors
Royal Group of Hospitals Trust
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: Healthy individuals, age 18 - 60 years. Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18-64 years) yes F.1.2.1 Number of subjects for this age range F.1.3 Elderly (>=65 years) no F.1.3.1 Number of subjects for this age range
Exclusion criteria
Exclusion criteria: Use of other anti-platelet drugs (thienopyridines, GPIIb/IIIa antagonists, dipyridamole) because these drugs would also interfere with platelet function assays; Use of other non-steroidal anti-inflammatory drugs, because of pharmacodynamic interactions; History of dyspepsia or peptic ulceration requiring treatment with proton pump inhibitor or H2-antagonist, in view of the increased risk of gastrointestinal haemorrhagic complications; History of systemic inflammatory diseases, in view of the need for these patients to take anti-inflammatory drugs; History of asthma; Use of other medications including aspirin (including herbal preparations); Family or personal history of bleeding disorders, in order to reduce the potential for haemorrhagic complications; Use of oral anticoagulants; Platelet count outside the normal range (150,000 - 450,000 / ml), as these patients require further investigation and aspirin use is contra-indicated in patients with significant thrombocytopaenia; Significant anaemia (Hb 40 units per week); Inability to provide informed consent.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Main Objective: The aims of this proposed study are to use a repeated measures crossover trial design in order to: assess the reproducibility of aspirin resistance in healthy control individuals, as defined by standard optical platelet aggregometry, characterise the contribution of genetic polymorphisms in candidate genes, specifically the cyclooxygenase and adenosine 5-diphosphate receptor genes, to the phenomenon of aspirin resistance. ;Secondary Objective: The secondary outcome measures are: the assessment of the reproducibility of aspirin response as defined by other platelet function tests (PFA-100, thromboxane levels), the contribution of other genetic polymorphisms to the phenomenon of aspirin resistance, and the correlation between the various platelet function tests used in this study.;Primary end point(s): The primary outcome measures for this proposed study are the assessment of the reproducibility of aspirin response in healthy control individuals, as defined by standard optical platelet aggregometry, and the contribution of the Cyclooxygenase and Adenosine 5-diphosphate receptor gene polymorphisms to the phenomenon of aspirin resistance. | — |
Countries
United Kingdom
Outcome results
None listed