FS 205-397: a new antipyretic analgesic with a paracetamol-like profile of activity but lack of acute hepatotoxicity in mice.

FS 205-397 has been designed to mimic or improve the antipyretic/analgesic profile of paracetamol but without inducing hepatic failure. FS 205-397 offers advantages over acetylsalicylic acid since it has caused no gastric lesions in rats and unlike paracetamol it produced no hepatotoxicity in animal models. The antinociceptive potency of FS 205-397 was at least that of acetylsalicylic acid and paracetamol and in some models it was somewhat more potent. FS 205-397 was even active in the hot plate test, a model in which most non-narcotics are inactive. FS 205-397 will offer potent analgesic and antipyretic therapy in man based on an innovative biochemical principle which eliminates the undesirable toxic effects associated with most other non-narcotic analgesics.