Intramuscular administration of alfaxalone for sedation in rabbits

Abstract

Alfaxalone is a neuroactive steroid derivative of pregnanedione that was recently reintroduced to the market for use as an induction agent in small animal anaesthesia. The aim of this study was to determine an intramuscular alfaxalone dose for safe immobilisation. Ten healthy New Zealand white rabbits were used to evaluate a single intramuscular injection of alfaxalone. The design of the study was a three-way, complete block, cross-over trial to compare the effect of alfaxalone at three doses (4, 6 and 8 mg). The mean duration of the effect for the 4, 6 and 8 mg/kg doses was, respectively, 36.9 (95% CI (31.6 to 42.3)), 51.8 (46.4 to 57.2) and 58.4 (52.8 to 63.9) minutes. The loss of the righting reflex was achieved after 3.1 (2.5 to 3.8), 2.4 (1.7 to 3.1) and 2.3 (1.6 to 2.9) minutes, respectively. The mean duration of the effect for the 6 and 8 mg doses was significantly higher than for the 4 mg dose (with estimated differences of 14.8 95% CI (8.8 to 20.8) minutes and 21.4 (15.3 to 27.6) minutes, respectively). No significant dose effect was observed before the loss of the righting reflex (P=0.14). Ear pinching and limb withdrawal were elicited in all groups at every dose. Doses of 4 or 6 mg/kg could be recommended; higher doses do not provide clinical benefits and can be associated with anaesthetic complication.

Intramuscular Administration of Alfaxalone Alone and in Combination for Sedation and Anesthesia of Rabbits (Oryctolagus cuniculus)

“…This study builds on initial investigations of alfaxalone administered intramuscularly in rabbits. 13,16 The current study demonstrated that alfaxalone in combination with other sedatives produces prolonged and reliable sedation and, in some combinations, can provide anesthesia. Compared with the use of alfaxalone alone, the addition of midazolam increased the duration of sedation by an average of 25 min, and the addition of dexmedetomidine increased the duration of sedation by an average of 117 min.…”

“…The average duration of sedation in our study was 40 min for the 6-mg/kg alfaxalone group, which is lower than the 51.8 min reported elsewhere for the same dosage. 13 That study used male rabbits that were similar in age to our animals, so the difference may be due to sex-associated differences in sedation duration with intramuscular alfaxalone in rabbits. In addition, the relatively low numbers of animals in each study group may help to explain this observed difference.…”

Comparison of a Supraglottic Airway Device (v-gel®) with Blind Orotracheal Intubation in Rabbits

“…Hypoventilation is a common occurrence at induction and during general anesthesia in rabbits (2–4, 12). A frequent alternative to orotracheal intubation is the use of a facemask.…”

Sedative effects of intramuscular alfaxalone in pet guinea pigs ( Cavia porcellus )

“…Increasing the dose of IM alfaxalone would also increase the risk for cardiorespiratory side effects, as has been demonstrated in dogs, cats and rabbits (Huynh et al 2015;Tamura et al 2015a;Tamura et al 2015b). Moreover, because alfaxalone is only available in Europe at a concentration of 10 mg mL -1 doses higher than 5 mg kg -1 would result in unacceptably high IM injection volumes for small rodents.…”