[Pharmacological studies of a non-steroidal analgesic and antipyretic drug of LFP83].

ABSTRACT

Pharmacological properties of LFP83, a non-steroidal analgesic and antipyretic drug, were studied in mice, rats and rabbits. LFP83 is a prodrug of flurbiprofen (FP) which is its active major metabolite in vivo. In experimental models of acetic acid writhing, the Randall and Selitto method, arthritic pain, yeast fever, LPS fever, carrageenin edema and adjuvant arthritis, LFP83 (i.v.) showed remarkable analgesic, antipyretic and antiinflammatory activities; and it was more potent than ketoprofen (i.m.) and aspirin DL-lysine (i.v.). The analgesic activity of LFP83 was equal to or more potent than that of pentazocine, and its duration was longer than those of aspirin DL-lysine and pentazocine. In addition, the analgesic potency of LFP83 was approximately the same or more potent than that of FP (p.o.), and the onset of this analgesic effect began earlier. On the other hand, the ulcerogenic activity of LFP83 on rat gastric mucosa was less than that of FP (p.o.) in both single and consecutive (7 days) administrations. The safety index (UD50/ED50) of LFP83 was three to ten-fold higher than that of FP (p.o.). As mentioned above, LFP83 is a potent analgesic, antipyretic and antiinflammatory drug; and in comparison to oral FP, it has a more potent and immediate effect, weak gastric irritation and high safety index.