Pharmacology of a new non-steroidal, anti-inflammatory agent: 6,11-dihydro-11-oxodibenz [b, e] oxepin-2-acetic acid (HP 549).

HP 549 is an orally effective non-steroidal anti-inflammatory agent with moderate analgesic and antipyretic activity. It is active in adjuvant-induced polyarthritis when given prophylactically or therapeutically. HP 549 also inhibits carrageenan-induced paw edema in the rat, an activity which is not altered by adrenalectomy. The analgesic activity of HP 549 was demonstrated in phenylquinone writhing. However, HP 549 produced variable results in the Randall-Selitto analgesia test. The anti-pyretic activity of HP 549 appears to be weak. HP 549, unlike other pharmacologically active anti-inflammatory drugs, does not produce gastric irritation at effective doses and is 45 times less ulcerogenic than indomethacin. Also the acute therapeutic indices for HP 549 are more favorable than for indomethacin.