Clopidogrel, a new potent adenosine diphosphate (ADP)-receptor antagonist for the prevention of myocardial infarction and ischemic stroke

The common pathogenesis of myocardial infarction (MI) and ischemic stroke, which result in death and severe long-term disabilities for millions of individuals each year, is platelet-mediated thrombosis over a ruptured atherosclerotic plaque. Use of an antiplatelet drug such as aspirin or ticlopidine has been shown in extensive placebo-controlled studies to reduce the incidence of MI, stroke and other vascular mortality by 25-33%. Recently, a new antiplatelet agent, clopidogrel (Plavix®), has proven more potent and better tolerated than either of these earlier drugs. CAPRIE, a randomized, blinded, active-control trial involving 384 clinical centers in 16 countries, compared clopidogrel 75 mg and aspirin 325 mg in more than 19,000 patients following a recent MI or stroke, or with symptomatic peripheral arterial disease. The intention-to-treat analysis of the primary outcome cluster of MI, stroke or other vascular death showed an overall relative risk reduction of 8.7% in favor of clopidogrel. In addition, the safety of clopidogrel was found to be at least equivalent to that of medium-dose aspirin, with less significant bleeding, and markedly superior to ticlopidine. This favorable efficacy: safety ratio makes clopidogrel an antiplatelet agent of clinical importance in the prevention of this extremely common, and imminently life- threatening, disease process.