title: Effect of acepromazine and butorphanol on halothane minimum alveolar concentration in ponies.
abstract: The effect of i.v. acepromazine (0.05 mg/kg bwt), butorphanol (0.05 mg/kg bwt) and a combination of acepromazine and butorphanol on halothane minimum alveolar concentration (MAC) was determined in 7 mixed-breed ponies. Ventilation was controlled, and blood pressure and temperature were maintained within normal limits. Following the determination of baseline MAC, treatments were administered to each pony in a random manner. The control treatment was normal saline. The baseline halothane dMAC for the control group was 0.91 +/- 0.04%, and no significant change occurred after saline administration. Acepromazine decreased (P = 0.0001) the halothane MAC from mean +/- s.e. 0.92 +/- 0.02% to 0.58 +/- 0.04%, and the combination of acepromazine and butorphanol, decreased (P = 0.003) halothane MAC, from mean +/- s.e. 0.95 +/- 0.04% to 0.59 +/- 0.06%. This represents a decrease of 36.9 and 37.8%, respectively. However, the difference between these 2 treatments was not significant. Butorphanol did not significantly change the mean group value for MAC; nevertheless, 3 ponies had an increase, one a decrease, while the MAC did not change in the remaining 3 ponies following butorphanol treatment.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville 37901, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Doherty
authors.forename: D R
authors.initials: DR
authors.lastname: Geiser
authors.forename: B W
authors.initials: BW
authors.lastname: Rohrbach
mesh_terms: D000075:Acepromazine / Q000008:administration & dosage / Q000494:pharmacology*; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D018685:Anesthetics, Inhalation / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001831:Body Temperature / Q000187:drug effects / Q000502:physiology; D002077:Butorphanol / Q000008:administration & dosage / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D004347:Drug Interactions; D005260:Female; D006221:Halothane / Q000378:metabolism*; D006736:Horses / Q000378:metabolism* / Q000502:physiology; D007275:Injections, Intravenous / Q000379:methods / Q000662:veterinary; D008297:Male; D011650:Pulmonary Alveoli / Q000378:metabolism*; D012123:Pulmonary Ventilation / Q000187:drug effects / Q000502:physiology; D011897:Random Allocation
chemical_list: D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D018492:Dopamine Antagonists; D000075:Acepromazine; D002077:Butorphanol; D006221:Halothane