Loss of Effect of Aspirin on Platelet Aggregation During Chronic Administration

Platelet Aggregation Clinical Trial

Official title: Loss of Effect of Aspirin on Platelet Aggregation During Chronic Administration

Status Terminated

Clinical Trial Summary

Aspirin has shown to be beneficial to some patients with certain diseases such as coronary artery disease or stroke. We are investigating how aspirin works on regulating platelets and thromboxane over time at different doses. We hope to find the best dose of aspirin and/or other medications to help people who are at risk for heart attack or stroke.

Clinical Trial Description

he purpose of the study is to better understand the mechanism for failure of daily aspirin administration to prevent cardiovascular events in some at risk individuals. We seek to describe the effect of chronic aspirin administration at varying doses on platelet aggregation. This will help to define mechanisms for aspirin failure and to pursue possible alternative therapies in patients who fail to respond to aspirin therapy.

We hypothesize that (1) inhibition by aspirin (ASA) of ex vivo-induced platelet aggregation varies in a predictable time and dose dependent manner, (2) thromboxane and prostacyclin production is inhibited by ASA in a dose-dependent manner and remains relatively constant over time once maximal inhibition has occurred, and (3) granule secretion by platelets during induced aggregation is inhibited by aspirin acutely but this effect does not persist during chronic administration at high doses. ;

Related Conditions & MeSH terms

• Platelet Aggregation

• NCT number: NCT00748371
• Study type: Interventional
• Source: Vanderbilt University Medical Center
• Status: Terminated
• Phase: Phase 4
• Start date: June 2004
• Completion date: February 2011