Evaluation of Analgesic Agents in Rats with Adjuvant Arthritis

Abstract

Rats with adjuvant arthritis were used for an analgesic test in which flection stimuli were applied to the arthritic joints. TAI-284, indomethacin, phenylbutazone, mefenamic acid, ibufenac, aspirin and aminopyrine were effective at the relatively low doses in this method. Oral ED₅₀s of these compounds run parallel to their clinical doses. The method detects not only the analgesic action of morphine, pethidine and codeine, but also that of nalorphine, pentazocine and amphetamine. Prednisolone was mildly effective dose-independently. In spite of the high sensitivities, the method was specific in the sense that CNS-depressant, anti-depressant, anti-epileptic, naloxone, anti-serotonin and anti-histamine drugs were inactive or slightly active at toxic doses. The arthritic flection pain test was concluded to be a sensitive and specific test.