Combination treatment with dipyridamole, aspirin, and tPA in an embolic model of stroke in rats

June 2007

Several studies have already shown that antithrombotic treatment is an effective therapy in preventing secondary strokes. Inhibition of platelet aggregation can effectively reduce formation of thrombi which reduces the incidence of stroke. However, inhibition of platelet aggregation is often correlated with an increased risk of bleeding events.

Dr S. Aldandashi and his colleagues from the University of Alberta, Canada, tried to test the protective effects of combination therapy with dipyridamole and acetylsalicylic acid (ASA) in comparison to ASA alone, and whether such combination treatment may produce any added benefits when tissue plasminogen activator (tPA) treatment is also used. The study was divided into three parts. In the first part (A) the effect of antiplatelets on infarct volume was assessed, in the second (B), perfusion deficits were measured and in the last (C), efficacy of antiplatelet therapy in combination with tPA was assessed.
The investigators found that in part A, dipyridamole and aspirin treatment significantly reduced infarct volume as well as that in part B, treatment with dipyridamole significantly reduced the perfusion deficits as compared to control. Most interestingly was what the researcher found in part C: dipyridamole plus tPA or dipyridamole and aspirin plus tPA significantly decreased infarct volume as compared to tPA alone.

Based on the results of their study, the investigators derived that there is significant protection with dipyridamole as both infarct volume and perfusion deficits are significantly reduced. They found that dipyridamole with tPA also significantly reduced infarct volume as compared to tPA alone. “Our data suggests that higher doses of antithrombotic therapy with dipyridamole offer best neuroprotection”, Dr Aldandashi and his colleagues write.