Nolan A, Waterman A E, Livingston A
Department of Veterinary Surgery, University of Bristol, Langford, U.K.
J Vet Pharmacol Ther. 1988 Mar;11(1):94-102. doi: 10.1111/j.1365-2885.1988.tb00126.x.
The analgesic activity of pethidine was measured in eight sheep using both thermal and mechanical test systems. Pethidine, at a dose rate of 5 mg/kg body weight given intravenously, produced a significant degree of antinociception to thermal pain for 30 min (on average) but gave only a few minutes of significant analgesia when tested in the mechanical pressure system. Analgesia in both systems was abolished by pretreatment with naloxone. Pharmacokinetic analyses of plasma levels of pethidine after intravenous (i.v.) injection were carried out. Plasma concentrations of the drug exhibited a rapid biexponential pattern of decline with an average distribution half-life of 0.99 min and an elimination half-life of 12.8 min. Correlation of plasma levels of the drug with the presence of a significant degree of antinociception in the thermal test system enabled 'critical' analgesic levels of pethidine to be defined for sheep (0.93 microgram/ml).
使用热刺激和机械刺激测试系统，在八只绵羊身上测量了哌替啶的镇痛活性。静脉注射剂量为5mg/kg体重的哌替啶，平均可产生30分钟的显著热痛抗伤害感受，但在机械压力系统测试中，仅产生几分钟的显著镇痛效果。两种系统中的镇痛作用均被纳洛酮预处理所消除。对静脉注射哌替啶后的血浆水平进行了药代动力学分析。药物的血浆浓度呈现出快速的双指数下降模式，平均分布半衰期为0.99分钟，消除半衰期为12.8分钟。通过将药物的血浆水平与热测试系统中显著程度的抗伤害感受相关联，确定了绵羊的哌替啶“临界”镇痛水平（0.93微克/毫升）。
