Analgesic and antipyretic effects of trilobine hydrochloride without induction of physical dependence

Trilobine-HCI raised the pain thresholds during hot-plate test in mice, tail flick test in rats and writhing test in mice. Daily ip of 30 mg/kg×5 d in mice did not induce tolerance as seen with morphine. After in for 7 times within 2 d at 2.5 to 35 mg/kg in mice and then challenged with nalorphine 50 mg/kg, no jumping response was seen. In morphine-addicted rats the body weight was restored after sc morphine but not after trilobine. In morphine-addicted monkeys sc trilobine could not substitute morphine for releving the withdrawal syndromes. The results demonstrate that trilobine acts as an analgesic drug, shows no morphine-like tolerance nor physical dependence. Hence it belongs to the non-narcotic group.