The thienopyridines in coronary artery disease

The thienopyridine class of antiplatelet drugs includes ticlopidine and clopidogrel, drugs that are used increasingly to prevent ischemic events in and out of the cardiac catheterization laboratory. Formerly, the only oral antiplatelet drug available for these purposes was aspirin, which has been studied randomized placebo-controlled trials in which 70,000 patients have been enrolled. Aspirin resulted in a 27% reduction in vascular death, myocardial infarction, and stroke in these trials. Aspirin is a weak antiplatelet agent; however, its side effects can cause in tolerance, and between 15% and 45% of patients are resistant to its antiplatelet effects. Both ticlopidine and clopidogrel have been compared with aspirin in randomized controlled trials and both are approximately 10% more effective than aspirin. Recently, ticlopidine and clopidogrel have been compared with one another; clopidogrel appears to be at least as efficacious as ticlopidine, but with few fewer side effects.