Peripherally acting α-adrenoceptor antagonist MK-467 with intramuscular medetomidine and butorphanol in dogs: A prospective, randomised, clinical trial.
The aim of this study was to investigate the clinical usefulness of MK-467 (vatinoxan; L-659'066) in dogs sedated for diagnostic imaging with medetomidine-butorphanol. It was hypothesised that MK-467 would alleviate bradycardia, hasten drug absorption and thus intensify the early-stage sedation. In a prospective, randomised, blinded clinical trial, 56 client-owned dogs received one of two IM treatments: (1) 0.5mg/m2 medetomidine+0.1mg/kg butorphanol (MB, n=29); or (2) 0.5mg/m2 medetomidine+0.1mg/kg butorphanol+10mg/m2 MK-467 (MB-MK, n=27). Heart rates and visual sedation scores were recorded at intervals. Plasma drug concentrations were determined in venous samples obtained approximately 14min after injection. Additional sedation (50% of original dose of medetomidine IM) and/or IM atipamezole for reversal were given when needed. The area under the sedation score-time curve for visual analogue scale (AUCVAS30) was calculated for the first 30min after treatment using the trapezoidal method. Repeated ANOVA, Mann-Whitney U test and Fisher's exact test were used for parametric, non-parametric and dichotomous data. Heart rate was significantly higher from 10 to 40min with MB-MK than with MB. AUCVAS30 was significantly higher after MB-MK. More dogs treated with MB-MK required additional sedation after 30min, but fewer needed atipamezole for reversal compared with MB. Plasma concentrations of both medetomidine and butorphanol were higher after MB-MK. All procedures were successfully completed. MK-467 alleviated the bradycardia, intensified the early stage sedation and shortened its duration in healthy dogs that received IM medetomidine-butorphanol.
['Kallio-Kujala|I J|IJ|', 'Turunen|H A|HA|', 'Raekallio|M R|MR|', 'Honkavaara|J M|JM|', 'Salla|K M|KM|', 'Casoni|D|D|', 'Hautajärvi|H J|HJ|', 'Vainio|O M|OM|']
D000317:Adrenergic alpha-Antagonists D000818:Animals D002077:Butorphanol D016292:Conscious Sedation D003952:Diagnostic Imaging D004285:Dogs D004338:Drug Combinations D005260:Female D006993:Hypnotics and Sedatives D007273:Injections, Intramuscular D008297:Male D020926:Medetomidine D011446:Prospective Studies D011807:Quinolizines D011897:Random Allocation D016896:Treatment Outcome
MK-467 Medetomidine Butorphanol Anaesthesia Canine