Sodium salicylate does not prevent the inhibitory effect of indomethacin on thromboxane formation in human blood ex vivo.
Thromboxane formation during spontaneous blood clotting as well as plasma levels of TXB2 and 6-keto-PGF1 alpha, the stable metabolites of TXA2 and prostacyclin, were measured by radioimmunoassay two hours after oral administration of indomethacin (25 mg), sodium salicylate (250 mg) and their combination to human volunteers. Indomethacin effectively suppressed the tremendous formation of TXB2 during blood clotting whereas sodium salicylate had only a slight inhibitory effect on TXB2 synthesis. The combination of indomethacin and sodium salicylate inhibited the formation of thromboxane even slightly more effectively than indomethacin alone. Plasma TXB2 level was decreased after the combination treatment but not after administration of either of the drugs alone. Plasma 6-keto-PGF1 alpha level was not changed by any of the treatments. The present study suggests that simultaneous oral administration of sodium salicylate together with indomethacin at a combination ratio of 10 to 1 does not significantly interfere with the inhibitory effects of indomethacin on thromboxane synthesis in human blood ex vivo.
D015121:6-Ketoprostaglandin F1 alpha / Q000097:blood; D000328:Adult; D001777:Blood Coagulation / Q000187:drug effects*; D006801:Humans; D007213:Indomethacin / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D011863:Radioimmunoassay; D012980:Sodium Salicylate / Q000008:administration & dosage / Q000494:pharmacology*; D013929:Thromboxane B2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D013931:Thromboxanes / Q000096:biosynthesis*
D013931:Thromboxanes; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D012980:Sodium Salicylate; D007213:Indomethacin