The influence of route of administration upon the sedative effect of romifidine in dogs

SUMMARY The sedative and some physiological effects of iv romifidine at 120 μg/kg bwt were compared with the same dose administered subcutaneously (sc) and an iv placebo in 12 clinically normal adult beagle dogs in a blinded randomised change-over study. Following iv romifidine, the dogs became recumbent and there was an increase in a subjective score awarded to the degree of sedation. Heart rate and respiratory rate decreased and minor bradyarrhythmias were noted. When romifidine was given sc the onset of sedation was slower, and the magnitude of the sedative effect was less until 30 min after administration, after which time sedation was no different between the 2 routes of administration. Recovery from sedation was similar following either route. Heart rate and respiratory rate changes were similar with either route although respiratory rate decreased more quickly following iv romifidine. It appears therefore that, in dogs, romifidine is equally efficacious by either iv or sc routes.