[Antiplatelet drugs for prevention of cerebral ischemic accidents]

Antiplatelet (AP) drugs play a major role in stroke prevention. Aspirin (50-1300 mg), ticlopidine (500 mg), clopidogrel (75 mg) and dipyridamole (400 mg) are effective in secondary prevention of atherothrombotic brain infarcts. Aspirin has been the most extensively studied drug and remains the most cost-effective one. The optimal dose is still debated; doses between 100 and 300 mg are the most widely used. The preventive efficacy of aspirin is already present at the acute phase of cerebral infarct. In primary prevention, aspirin nearly halves the risk of myocardial infarction but does not reduce that of stroke. Cardiac diseases with a high embolic risk require the use of oral anticoagulation. In non valvular atrial fibrillation, the choice of antithrombotic drugs depends on risk stratification: oral anticoagulants are indicated in high risk subjects whereas aspirin is recommended in low risk subjects and when oral anticoagulants are contraindicated. Studies with new associations of AP and with new drugs are required to increase the yield of the antiplatelet approach in high risk subjects; this should be done in parallel with efforts to detect and to treat the vascular risk factors associated with the development of a mass approach for stroke primary prevention.