Fielding S, Wilker J, Hynes M, Szewczak M, Novick W J, Lal H
J Pharmacol Exp Ther. 1978 Dec;207(3):899-905.
Clonidine was found to possess dose-dependent analgesic and antiwithdrawal activity. In mice, clonidine prolonged the tail flick latency and inhibited phenylquinone-induced writhing. In rats, it inhibited tail withdrawal from hot water and a pain response to pressure application on an inflamed paw. The effective doses of clonidine were different in the different tests employed, but they were always smaller than those of morphine. Naloxone failed to antagonize the analgesic actions of clonidine but effectively antagonized those of morphine. Phenoxybenzamine also did not alter the inhibition of tail flick-induced by clonidine. Clonidine suppressed morphine withdrawal body shakes in a dose-dependent manner as does morphine. This action of clonidine was not reversed by naloxone. In usual laboratory tests, clonidine appears to be an effective analgesic which antagonizes signs of morphine withdrawal.
可乐定具有剂量依赖性镇痛和抗戒断活性。在小鼠中，可乐定可延长甩尾潜伏期并抑制苯醌诱导的扭体反应。在大鼠中，它可抑制尾部从热水中缩回以及对发炎爪子施加压力的疼痛反应。可乐定在不同测试中的有效剂量不同，但始终小于吗啡的有效剂量。纳洛酮未能拮抗可乐定的镇痛作用，但能有效拮抗吗啡的镇痛作用。酚苄明也未改变可乐定诱导的甩尾抑制作用。可乐定与吗啡一样，以剂量依赖性方式抑制吗啡戒断时的身体颤抖。可乐定的这一作用不能被纳洛酮逆转。在常规实验室测试中，可乐定似乎是一种有效的镇痛药，可拮抗吗啡戒断症状。
