The effect of two low doses of aspirin on whole blood thromboxane and prostacyclin generation in healthy subjects.

The effects of two low doses of aspirin (20 mg and 100 mg) on prostacyclin and thromboxane formation during whole blood clotting were studied in 8 healthy volunteers. A single 100 mg aspirin dose caused more than 90% reduction of both serum TXB2 and 6-keto-PGF1 alpha; a single 20 mg dose of aspirin inhibited serum TXB2 more than 6-keto-PGF1 alpha but effects on these two products could not be completely dissociated. However, the effect of a single 20 mg aspirin dose on serum TXB2, was of much longer duration than its inhibitory effect on PGI2 synthesis during whole blood clotting.