Dosage of acetylsalicylic acid for inhibition of platelet function

In normal males, platelet prostaglandin synthesis as measured by malondialdehyde (MDA) production is blocked by more than 90% after administration of 600 mg of calciumacetylsalicylic acid and by more than 50% after 100 mg. Repeated doses of 100 mg at 12 h intervals progressively decrease MDA production to below 10% of the basic value. Bleeding time increases from 3.38 +/- 0.36 min to 7.73 0.91 min (mean +/- SEM). The data indicate that 12 h 100 mg doses of calciumacetylsalicylic acid (equal to 80 mg of aspirin) adequately inhibit platelet function.