Waterman A E, Kalthum W
Department of Veterinary Surgery, University of Bristol, Langford, UK.
J Vet Pharmacol Ther. 1990 Jun;13(2):137-47. doi: 10.1111/j.1365-2885.1990.tb00761.x.
The pharmacokinetics of pethidine were investigated in dogs suffering from portosystemic vascular shunts and hepatic parenchymal disease. The drug was administered post-operatively at a dose rate of 2.0 mg/kg either intravenously or intramuscularly. When the drug was given intravenously to dogs suffering from intrahepatic shunts, the elimination half life was 75.5 +/- 4.2 min and the clearance rate was 29.0 +/- 2.3 ml/kg min. When the drug was given intramuscularly its rate of absorption was very slow (57.9 +/- 6.1 min) and the time taken to reach the maximum plasma concentration was long at 26.7 +/- 6.4 min. The elimination half-life for the intramuscularly administered drug was also very slow at 108.0 +/- 13 min, reflecting the reduced ability of these dogs to metabolize and eliminate pethidine. These findings suggest that caution should be exercised in the administration of pethidine to dogs suffering from hepatic dysfunction. In particular, the slower rate of absorption should be remembered in judging whether or not maximum effects have been achieved and the longer elimination half-life indicates the need to extend the intervals between repeat doses of this analgesic.
研究了患有门体循环血管分流和肝实质疾病的犬体内哌替啶的药代动力学。术后以2.0mg/kg的剂量速率通过静脉注射或肌肉注射给药。当对患有肝内分流的犬静脉注射该药物时，消除半衰期为75.5±4.2分钟，清除率为29.0±2.3ml/kg·min。当肌肉注射该药物时，其吸收速率非常缓慢（57.9±6.1分钟），达到最大血浆浓度所需的时间较长，为26.7±6.4分钟。肌肉注射给药的消除半衰期也非常缓慢，为108.0±13分钟，这反映出这些犬代谢和消除哌替啶的能力降低。这些发现表明，对肝功能不全的犬使用哌替啶时应谨慎。特别是，在判断是否已达到最大效果时应记住吸收速率较慢，而较长的消除半衰期表明需要延长这种镇痛药重复给药的间隔时间。
