General pharmacology of a new analgesic-AP-237.

1-n-Butyryl-4-cinnamylpiperazine hydrochloride, AP-237, was studied in a variety of general screening tests. Several routes of administration, including oral, subcutaneous, intraperitoneal, and intra-muscular, were employed. It was compared to morphine and pentazocine in many tests. It was found to be a potent analgesic in rats and mice with better oral efficacy than the reference agents. It did not exhibit anti-inflammatory, antipyretic, or anticonvulsant activity but appeared to have some tranquilizing properties. Its general pharmacology resembles the reference agents morphine and pentazocine, but with several differences.