Comparison of the efficacy and adverse effects of sustained-release buprenorphine hydrochloride following subcutaneous administration and buprenorphine hydrochloride following oral transmucosal administration in cats undergoing ovariohysterectomy.

OBJECTIVE: To compare the efficacy and adverse effects of sustained-release (SR) buprenorphine following SC administration and buprenorphine following oral transmucosal (OTM) administration in cats undergoing ovariohysterectomy. Animals-21 young healthy female cats. PROCEDURES: As part of anesthetic premedication (0 hours), 10 cats received buprenorphine (0.02 mg/kg) via OTM administration with additional doses at 12, 24, 36, 48, and 60 hours and 11 cats received an equivalent total dose as a single SC injection of SR buprenorphine (0.12 mg/kg). The SR product contained buprenorphine hydrochloride in a proprietary SR matrix. All other anesthetic drugs and a single postoperative dose of meloxicam were administered similarly to all cats. Behavioral and physiologic variables were recorded, and signs of pain were assessed by use of 2 pain assessment scales and von Frey filament testing in each cat prior to premedication administration (baseline), during recovery from anesthesia (RFA), and at 12, 24, 36, 48, 60, and 72 hours.
RESULTS: Heart rate increased and temperature (determined via microchip transponder thermometry) decreased from baseline values during RFA in both groups. Compared with baseline values, pain scores were increased during RFA and at the 12- and 24-hour time points in both groups; von Frey scores were higher during RFA. Behavioral and physiologic variables did not differ significantly between groups at any time point. CONCLUSIONS AND CLINICAL RELEVANCE: In cats undergoing ovariohysterectomy, SC administration of a preoperative dose of SR buprenorphine appeared to have comparable efficacy and adverse effect profile as that of twice-daily OTM administration of buprenorphine before and after surgery.