Effect of acepromazine and butorphanol on halothane minimum alveolar concentration in ponies

Abstract

Summary 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 MAC 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.

Effect of acepromazine, butorphanol, or N-butylscopolammonium bromide on visceral and somatic nociception and duodenal motility in conscious horses

“…This could have been because butorphanol administration decreased the initial painful stimuli immediately after surgery, which thus prevented a wind-up phenomenon. 40 The difference between alterations in duodenal and colorectal distention thresholds was likely related to the criteria used for a positive response. 35 Administration of NBB resulted in tachycardia and visceral antinociception, which was indicated by a significant increase in colorectal distention threshold and a slight but nonsignificant increase in duodenal distention threshold.…”

Effects of acepromazine and butorphanol on tiletamine-zolazepam anesthesia in llamas

“…12 There is, however, reason to expect an improvement in antinociception with the combination of acepromazine and butorphanol, and there is evidence for an interaction between the dopaminergic and opioid receptor systems. These findings are consistent with the interaction of acepromazine and butorphanol with volatile anesthetics in ponies, in which the drug combination did not reduce the minimum alveolar concentration by a greater margin than did acepromazine alone.…”

“…[6][7][8] The effects of butorphanol in awake llamas are unpredictable and may result in sedation or excitment. 7,8,12,13 It has antagonistic properties at dopamine D 2 receptors, in addition to actions at catecholamine, 5-hydroxytryptamine 2, and histamine receptors. 10 Acepromazine, a neuroleptic drug belonging to the phenothiazine group, 11 is widely used in domestic animals either for sedation or as an anesthetic premedication.…”

Interactions of morphine and isoflurane in horses

“…For example, it is widely appreciated that many horses have undesirable and even dangerous behavioral actions following opioid administration. [6][7][8][9][10][11] In addition, results of the limited number of pertinent studies [12][13][14][15] of opioid-inhalation anesthetic interactions in horses and ponies do not provide strong evidence in support of consistent, effective contributions from the use of opioids to improve anesthetic management of horses. Accordingly, additional study of the effectiveness of opioids as adjuvants in the anesthetic management of horses is necessary to support or refute common use in this species.…”