The antiinflammatory profile of (5H-dibenzo[a,d]-cyclohepten-5-ylidene)acetic acid (WY-41,770), an agent possessing weak prostaglandin synthetase inhibitory activity that is devoid of gastric side effects.

Wy-41,770 [(5H-dibenzo[a,d]cyclohepten-5-ylidene)acetic acid], a novel acrylic acid, was compared to indomethacin and aspirin in standard antiinflammatory, analgesic and antipyretic animal models. The acute antiinflammatory, analgesic and antipyretic activity of Wy-41,770 (oral ED50S 50-170 mg/kg) was similar to aspirin; however, it was considerably more potent orally in adjuvant arthritis in the rat (ED50, 16 mg/kg) and urate-induced synovitis in the dog (ED50, 4.5 mg/kg). Wy-41,770 was a weak inhibitor of prostaglandin biosynthesis and did not inhibit either 5- or 15-lipoxygenase. Furthermore, the cellular migration characteristic of carrageenan pleurisy was not affected by Wy-41,770. Unlike a majority of NSAIDs, it produced no gastric irritation in rats after either acute or chronic oral administration over the range 400-800 mg/kg. The major mechanism of action of Wy-41,770 has yet to be identified but does not seem to involve interference of arachidonic acid metabolism.