Effect of triflusal and acetylsalicylic acid on platelet aggregation in human whole blood: influence of red blood cells and leukocytes.

A study has been made on the in vitro effect of triflusal, acetylsalicylic acid (ASA and their major metabolite, 2-hydroxy-4-trifluoromethylbenzoic acid (HTB), and salicylic acid (SA), on platelet aggregation in human whole blood. SA exhibited no significant antiplatelet effects (IC50 greater than 2mM) against several inducers; the IC50 values for the other compounds were: triflusal, 140 microM against ADP and 63.2 microM against collagen; HTB, 100 microM against ADP and 260 microM against collagen; ASA 687 microM against ADP and 9.3 microM against collagen. Red blood cells potentiate the antiaggregant effect of HTB and of triflusal, and to a lesser extent, that of ASA; leukocytes primarily potentiate the effect of ASA and, to a lesser extent, that of triflusal.