A randomized clinical trial comparing butorphanol and buprenorphine within a multimodal analgesic protocol in cats undergoing orchiectomy

Abstract

Objectives The aim of this study was to compare the effects of butorphanol and buprenorphine, as part of a multimodal analgesic protocol, on recovery and analgesia in cats undergoing orchiectomy. Methods In a prospective, randomized, blind clinical trial, 47 adult male cats were randomly assigned to receive either butorphanol (0.3 mg/kg, n = 24) or buprenorphine (0.02 mg/kg, n = 23) in combination with dexmedetomidine (25 μg/kg) and alfaxalone (2 mg/kg) as a single intramuscular injection for the induction of general anesthesia. Isoflurane carried in oxygen was supplemented as needed during orchiectomy. All cats received lidocaine (2 mg/kg intratesticular), meloxicam (0.3 mg/kg SC) and atipamezole (125 μg/kg IM) postoperatively. Pain and sedation scales were applied at baseline, and 2, 4 and 6 h postoperatively. Time to achieve sternal recumbency and to begin eating were also recorded. Results Pain scale scores were low and showed no difference between the treatment groups at all time points ( P ⩾0.99, all time points). Four cats exceeded the analgesia intervention threshold for rescue analgesia (butorphanol, n = 3; buprenorphine, n = 1). There was no difference in sedation scores between groups at any time point ( P >0.99, all time points). Significantly more cats in the buprenorphine group (n = 12) required isoflurane than in the butorphanol group (n = 2) ( P = 0.0013; relative risk 6.3, 95% confidence interval [CI] 1.8–23.5). There was no significant difference in time to achieve sternal recumbency ( P = 0.96, 95% CI –20 to 20) between groups or in return to eating ( P = 0.48, 95% CI –92.0 to 113.5), with most cats eating within 1 h of surgery (butorphanol, 79%; buprenorphine, 83%). Conclusions and relevance There were no significant differences in analgesia or recovery between butorphanol and buprenorphine treatment groups as part of a multimodal injectable anesthetic protocol. Butorphanol is associated with superior depth of anesthesia, facilitating injectable anesthesia.

Retrospective investigation of an association between high-dose buprenorphine and perpetuation of post-anesthesia hyperthermia in cats following ovariohysterectomy

“…Buprenorphine is a partial mu (µ)-agonist opioid that is widely used for perioperative analgesia in cats. 1,2 A high concentration, US Food and Drug Administration-approved buprenorphine formulation (Simbadol; Zoetis) specifically labeled for use in cats is available as a single-dose subcutaneous (SC) injection and is reported to provide 24 h analgesia. The prolonged analgesic effect of this formulation is attributed to the concentration and dose of the compound, in addition to its high affinity for the µ receptor.…”

Effects of ketamine, midazolam and methadone, combined with local anesthesia, in cats undergoing orchiectomy

“…The maintenance of the intraoperative HR and SAP values and absence of voluntary movement in response to surgical manipulation may indicate the effectiveness of the anesthetic block in feline orchiectomy, as described in previous studies (ARMSTRONG et al, 2018;MOSER et al, 2020;GOMES et al, 2021;GOMES et al, 2022); however, the action of propofol cannot be disregarded, especially in relation to the maintenance of immobility during surgery.…”

The history and pharmacology of buprenorphine: New advances in cats

“…In cats, morphine has been associated with lower heart rate and hypotension that is responsive to glycopyrrolate (Bauquier, 2012) as well as naloxone-responsive histamine release (Evangelista et al, 2016). Buprenorphine-induced cardiovascular effects have not been observed in cats, nor cardiovascular-related adverse events at clinical doses (Bhalla et al, 2018;Bortolami & Love, 2015;Clark et al, 2022aClark et al, , 2022bEvangelista et al, 2017;Mahdmina et al, 2020;Moser et al, 2020;Shah et al, 2019;Steagall et al, 2014Steagall et al, , 2018Warne et al, 2016). In an echocardiographic study evaluating buprenorphine (0.01 mg/kg IM)-dexmedetomidine (0.04 mg/kg IM) sedation in cats, blood pressure increased, and heart rate decreased post-sedation (Johard et al, 2018).…”