Reduction of urinary excretion of PGE2 and 6 keto PGF1 alpha by tiaprofenic acid.

Tiaprofenic acid (Surgam, Cassenne) was administered intravenously to saline-diuretic conscious rats, at doses of 2, 10 and 25 mg kg-1 body weight. Tiaprofenic acid significantly reduced urinary prostaglandin E2 (PGE2) and 6 keto PGF1 alpha excretion, at all three doses employed. The extent of the reduction was similar for both PGE2 and 6 keto PGF1 alpha output; hence no evidence of 'selectivity' (i.e. sparing of PGI2 synthesis) was observed. Tiaprofenic acid was also administered to rats receiving an infusion of 5% dextrose. The dose employed (0.5 or 1 mg kg-1 body weight) was submaximal and elicited reductions in PGE2 output to values still more than 60% of the control period values. In this group of animals, the percentage change in 6 keto PGF1 alpha excretion was again not significantly different from that of PGE2. The maximal extent of reduction in urinary PGE2 excretion with tiaprofenic acid (25 mg kg-1 body weight) was not significantly different from that elicited by indomethacin (10 mg kg-1 body weight), although the time course of the reduction was different.