Objective

To assess analgesic efficacy and the pharmacokinetics of intranasal (IN) tramadol in dogs following ovariohysterectomy.

Study design

Randomized, blinded clinical study.

Animals

A total of 30 bitches undergoing elective ovariohysterectomy.

Methods

Dogs were randomly assigned to one of three experimental groups (10 dogs per group): IN tramadol 4 mg kg^–1 (group T-IN), intravenous (IV) tramadol 4 mg kg^–1 (group T-IV) and IV methadone 0.2 mg kg^–1 (group M). Drugs were administered at extubation. At established time points (before surgery and up to 8 hours after drug administration) analgesia was assessed using the Italian version of the Glasgow Composite Measure Pain Scale Short Form and physiological variables were recorded. To determine the pharmacokinetics of IN tramadol, blood samples were collected at predetermined time points. Shapiro–Wilk test was used to assess whether data were normally distributed and consequently parametric or non parametric tests were applied. A p value < 0.05 was considered significant.

Results

No significant intergroup differences were observed in the dogs that were administered rescue analgesia and time of its administration. Excluding dogs that were administered rescue analgesia, no significant intergroup differences emerged in pain scores and physiological variables, except for a lower rectal temperature in group M compared with the tramadol groups. After IN administration, tramadol was rapidly absorbed into the systemic circulation, reaching its maximum concentration (range 74.74–200.29 ng mL^–1) within 30–60 minutes, it then decreased rapidly and was detectable in plasma for up to 2 hours after treatment in all dogs.

Conclusions and clinical relevance

IN tramadol administration appears to be as effective as IV tramadol and methadone treatments in pain management of dogs after elective ovariohysterectomy. Given its low concentrations and short detection time in plasma after the IN route, systemic tramadol action appears unlikely.

中文翻译：

---

卵巢子宫切除术后鼻内给予曲马多的药代动力学和镇痛效果。

目的

评估卵巢子宫切除术后狗的鼻内（IN）曲马多的镇痛功效和药代动力学。

学习规划

随机，盲法临床研究。

动物

共有30个母犬接受择期卵巢子宫切除术。

方法

将狗随机分为三个实验组之一（每组10只狗）：曲马多4 mg kg ^–1（T-IN组），静脉注射（IV）曲马多4 mg kg ^–1（T-IV组）和静脉注射美沙酮0.2 mg kg ^–1（M组）。拔管时给药。在确定的时间点（手术前和给药后最多8小时），使用意大利版的《格拉斯哥综合测量疼痛量表》简表评估镇痛效果，并记录生理变量。为了确定IN曲马多的药代动力学，在预定的时间点收集血液样品。Shapiro-Wilk检验用于评估数据是否呈正态分布，因此应用了参数检验或非参数检验。一个p 值<0.05被认为是显着的。

结果

在施行急救镇痛和施药时间的狗中没有观察到明显的组间差异。除施行急救镇痛的狗外，在疼痛评分和生理变量上没有出现明显的组间差异，除了与曲马多组相比，M组的直肠温度更低。IN给药后，曲马多迅速吸收到体循环中，在30–60分钟内达到最大浓度（范围74.74–200.29 ng mL ^–1），然后迅速下降，并在治疗后长达2小时的血浆中可检测到。所有的狗。

结论与临床意义

在选择性卵巢子宫切除术后，在狗的疼痛管理中，曲马多的静脉内给药似乎与静脉曲马多和美沙酮治疗一样有效。由于其低浓度且IN路径后血浆中的检测时间短，因此全身性曲马多作用似乎不太可能。