How do antiplatelet agents compare in preventing strokes or transient ischemic attacks?
Dipyridamole ER-plus-aspirin may be superior to aspirin alone in reducing the risk of stroke in patients who have already had an ischemic stroke or a transient ischemic attack (NNT=33 in one study, but insignificant difference in another study). Headache and gastrointestinal adverse events were more common with dipyridamole ER-plus-aspirin compared to aspirin alone, but the risk of major bleeding was not increased. Ticlopidine is also superior to aspirin in preventing recurrent strokes (NNT=40) with the exception of African American patients, who show no difference. GI bleeding was less common in patients taking ticlopidine, but patients were more likely to develop diarrhea (NNH=10), a rash (NNH=16), or neutropenia (NNH=50). Clopidogrel, alone or with aspirin, has not been found to be beneficial in reducing the risk of stroke compared to aspirin alone, but clopidogrel-plus-aspirin was associated with higher rates of major bleeding.
