Antiplatelet agents for secondary prevention of ischemic stroke

OBJECTIVE: To review and summarize the efficacy, mechanisms of action, and cost of the options available when choosing antiplatelet agents for secondary stroke prevention. DATA SOURCES: This article is based on a review of the literature found with MEDLINE, CINAHL, and Cochrane Reviews (1980-June 2000) and abstracts from relevant international scientific meetings. We searched for the terms aspirin, ticlopidine, dipyridamole, antiplatelet, and clopidogrel. STUDY SELECTION: English-language articles, both reviews and original studies, were evaluated, and all information considered relevant was included in this review. In addition, guidelines from the American Heart Association are included. DATA SYNTHESIS: Aspirin is a relatively inexpensive and effective agent for secondary stroke prevention, and lower doses of aspirin appear as effective as higher doses. Ticlopidine has been used alone or in combination with aspirin, but serious adverse effects have limited its use. Clopidogrel has emerged as a safe and effective alternative to ticlopidine and lacks some of the serious adverse effects associated with ticlopicine, but is not superior to aspirin in secondary stroke prevention. Unlike previous studies, one recent trial showed that dipyridamole in combination with aspirin is superior to aspirin alone. CONCLUSIONS: Antiplatelet therapy is a key component of secondary prevention strategies in ischemic stroke. While aspirin has been the cornerstone in the management of stroke, other classes of antiplatelet drugs present new opportunities to optimize antiplatelet therapy.