Pharmacokinetic analysis of the pharmacodynamic difference of opioids in dogs and cats

阿片类药物对犬的镇痛作用呈剂量依赖性，并可抑制犬的意识水平、活动、心率和呼吸频率。相反，阿片类药物在猫中诱导的抗伤害效应较弱，即使在较高剂量下，对意识水平、活动、心率和呼吸频率的抑制也较少。药代动力学分析结果表明，这种药效学差异主要不是由药代动力学差异引起的，而是由于阿片受体分布或功能的差异。

Opioids induced dose-dependent antinociceptive effect and depression of conscious level, activity and heart rate and respiratory rate in dogs. In contrast, opioids induced weak antinociceptive effect and less depression of conscious level, activity, heart rate and respiratory rate even at higher dose of opioids in cats. Results of pharmacokinetic analysis have indicated that this pharmacodynamics difference is not caused by pharmacokinetic difference mainly, but rather by difference of the opioid receptor distribution or function.