Stroke extended-release dipyridamole

The European Stroke Prevention Study 2 (ESPS-2) trial examined four treatment arms—extended-release dipyridamole (ER-DP) 200 mg twice daily alone, aspirin 25 mg twice daily alone, ER-DP 200 mg twice daily + aspirin 25 mg twice daily, or placebo. In comparison with placebo the overall reduction in stroke risk was 16% with ER-DP alone and 18% with aspirin alone. The combination of ER-DP and aspirin led to a 37% reduction in stroke risk compared to placebo. Compared with aspirin alone, the combination of ER-DP with aspirin reduced the risk of stroke by 23%. 

The AHA/ASA guidelines recommend that antiplatelet therapy as the cornerstone of antithrombotic therapy for the secondary prevention of ischemic stroke and should be used in noncardioembolic strokes. Aspirin, dopidogrel, and extended-release dipyridamole plus aspirin are all considered first-line antiplatelet agents (see Table 13-1). The combination of aspirin and clopido-grel can only be recommended in patients with ischemic stroke and a recent history of myocardial infarction or coronary stent placement and then only with ultra-low-dose aspirin to minimize bleeding risk. 

Antiplatelet therapy reduces the risk of recurrent vascular events after TIA and ischemic stroke, although few trials have distinguished between different etiological subtypes (Antithrombotic Trialists Collaboration 2002). Most trial data concern aspirin, but other antiplatelet agents such as clopidogrel (CAPRIE Steering Committee 1996) or extended-release dipyridamole (Sivenius et al. 1991) have also been shown to be effective although mechanisms of action may differ (Table 24.2). 

All patients who have had an acute ischemic stroke or TEA should receive long-term antithrombotic therapy for secondary prevention. In patients with noncardioembolic stroke, this will be some form of antiplatelet therapy. In a recent meta-analysis, the overall benefit of antiplatelet therapy in patients with atherothrombotic disorders was estimated to be 22%. Aspirin is the best-studied of the available agents and, until recently, was considered the sole first-line agent. However, published literature has supported the use of clopidogrel and the aspirin plus extended-release dipyridamole combination product (ERDP + ASA) as additional first-line agents in secondary stroke prevention. 

Dipyridamole (persantine) is a vasodilator that, in combination with warfarin, inhibits embolization from prosthetic heart valves. A single study suggests that dipyridamole plus aspirin reduces strokes in patients with prior strokes or transient ischemic attack. A formulation containing 200 mg of dipyridamole, in an extended-release form, and 25 mg of aspirin (aggrenox) is available. 

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