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.
England
G C
GC
Department of Surgery and Obstetrics, Royal Veterinary College, University of London, Hatfield, Hertfordshire, UK.
Clarke
K W
KW
Goossens
L
L
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