A comparison of the sedative effects of three alpha 2-adrenoceptor agonists (romifidine, detomidine and xylazine) in the horse.
The sedative effects of a new alpha 2-adrenoceptor agonist, romifidine, were compared with those of xylazine and detomidine. Five horses were treated with two doses of romifidine (40 micrograms/kg body weight and 80 micrograms/kg body weight), two doses of detomidine (10 micrograms/kg body weight and 20 micrograms/kg body weight) and one dose of xylazine (1 mg/kg body weight) given by intravenous injection using a Latin-square design. The dose of 80 micrograms/kg romifidine appeared equipotent to 1 mg/kg xylazine and 20 micrograms/kg detomidine, although at these doses both xylazine and detomidine had a shorter action. Detomidine 20 micrograms/kg and xylazine both produced greater lowering of the head and a greater degree of ataxia than romifidine at either dose. Romifidine produced sedation similar to that of the other drug regimes. The effect upon imposed stimuli was similar.
Department of Surgery and Obstetrics, Royal Veterinary College, University of London, Hatfield, Hertfordshire, UK.
G C
GC
England
K W
KW
Clarke
L
L
Goossens
D000161:Acoustic Stimulation; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000818:Animals; D001259:Ataxia / Q000139:chemically induced / Q000662:veterinary; D006339:Heart Rate / Q000187:drug effects; D006734:Horse Diseases / Q000139:chemically induced; D006736:Horses / Q000502:physiology*; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D010413:Penis / Q000187:drug effects; D010775:Photic Stimulation; D010812:Physical Stimulation; D013546:Sweating / Q000187:drug effects; D014554:Urination / Q000187:drug effects; D014991:Xylazine / Q000494:pharmacology*
D000316:Adrenergic alpha-Agonists; D006993:Hypnotics and Sedatives; D007093:Imidazoles; D014991:Xylazine; C041255:detomidine; C076257:romifidine