EFFECT OF THE COMBINATION OF ANTIPLATELET AGENTS IN MAN - COMBINATION OF ASPIRIN, TRAPIDIL, TICLOPIDINE AND DIPYRIDAMOLE

An in vitro study of how platelet aggregation would be inhibited by the combination of aspirin or ticlopidine irreversibly inhibitory to platelet aggregation and trapidil or dipyridamole reversibly inhibitory, was carried out. The measured 50% inhibition concentrations indicated that aspirin was most inhibitory to collagen - induced platelet aggregation, followed by trapidil, ticlopidine and dipyridamole in decreasing sequence of inhibition. The combination of either aspirin or ticlopidine with trapidil inhibited platelet aggregation more intensely than the combination of either agent with dipyridamole. Thus, in clinical use of aspirin or ticlopidine, it may be expected that the lower dosage of aspirin or ticlopidine with lower frequencies of side effects inhibits platelet aggregation effectively with the combination of trapidil rather than dipyridamole.