Effects of dipyridamole and low-dose aspirin therapy on platelet adhesion to vascular subendothelium.
The effect on platelet function of low-dose aspirin (ASA) and dipyridamole alone or in combination was evaluated after repeated dosing in 5 healthy volunteers. The subjects were treated according to a randomized, single-blind, crossover design with 150 mg of dipyridamole, 25 mg of ASA, the 2 drugs together or placebo twice a day for 3 days. Platelet adhesin was evaluated using an experimental model of adhesion to rat aorta subendothelium under controlled hemodynamic conditions in the presence of red blood cells. Dipyridamole significantly reduced platelet adhesion both alone and in combination with ASA. ASA by itself did not significantly modify platelet adhesion, but completely blocked serum thromboxane production and platelet aggregation by arachidonic acid. Thus, low-dose ASA and dipyridamole may have a complementary action, modifying at the same time 2 platelet functions, adhesion and aggregation, both relevant in the pathogenesis of thrombosis.
D000328:Adult; D001241:Aspirin / Q000494:pharmacology*; D001808:Blood Vessels / Q000166:cytology / Q000187:drug effects*; D004176:Dipyridamole / Q000494:pharmacology*; D004338:Drug Combinations; D004727:Endothelium / Q000166:cytology / Q000187:drug effects; D006801:Humans; D008297:Male; D010973:Platelet Adhesiveness / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects
D004338:Drug Combinations; D004176:Dipyridamole; D001241:Aspirin