Observations on the use of medetomidine/ketamine and its reversal with atipamezole for chemical restraint in the mouse

Abstract

SummaryKetamine and medetomidine produced chemical restraint for minor procedures in mice. Male mice required SOmg/kg ketamine, 10 mg/kg medetomidine intraperitoneally (Lp.), and females a higher dose of ketamine 175 mg/kg i.p.l. The onset of restraint effects, judged by loss of righting reflex, was more rapid in males than females. The effects were reversed using atipamezole (1-2.5 mg/kg). Recovery following administration of atipamezole was more rapid in males than females. We conclude that ketamine/medetomidine, followed by reversal with atipamezole, is an effective technique for chemical restraint in the mouse.

Analyses of anaesthesia with ketamine combined with different sedatives in rats

“…In agreement with Cruz et al (1998), we also found that females recovered later after treatment with the ketamine/medetomidine combination than males, and with respect to different combinations, medetomidine was the drug that induced the longest period of anaesthesia in both sexes (Grint and Murison 2008). However, similar mean durations of anaesthesia with combinations of midazolam and medetomidine with ketamine at different doses have been reported in rabbits by Grint and Murison (2008).…”

“…Consequently, only the combination of α 2 -agonists and ketamine seems to be adequate at these doses for use as an anaesthetic because it reduces pain perception, as previously reported by other authors (Cruz et al 1998;Arras et al 2001). Similar to other authors, we did not observe an increase of diuresis (side-effect of α 2 -agonists), nor salivary secretion (Cruz et al 1998;Serrano-Caballero et al 2013). …”

“…This required administration of atipamezol in order to reverse these signs, but in spite of this, the two rats died. The relatively good results, in both males and females, for α 2 -agonist combinations (xylazine in males, and medetomidine in females), may be related to the described analgesic action of this group of drugs, which is why these combinations have been recommended by some authors (Cruz et al 1998;Arras et al 2001;Orr et al 2005). Consequently, only the combination of α 2 -agonists and ketamine seems to be adequate at these doses for use as an anaesthetic because it reduces pain perception, as previously reported by other authors (Cruz et al 1998;Arras et al 2001).…”

“…The relatively good results, in both males and females, for α 2 -agonist combinations (xylazine in males, and medetomidine in females), may be related to the described analgesic action of this group of drugs, which is why these combinations have been recommended by some authors (Cruz et al 1998;Arras et al 2001;Orr et al 2005). Consequently, only the combination of α 2 -agonists and ketamine seems to be adequate at these doses for use as an anaesthetic because it reduces pain perception, as previously reported by other authors (Cruz et al 1998;Arras et al 2001). Similar to other authors, we did not observe an increase of diuresis (side-effect of α 2 -agonists), nor salivary secretion (Cruz et al 1998;Serrano-Caballero et al 2013).…”

Reversal of Medetomidine-Ketamine Combination Anesthesia in Rabbits by Atipamezole

“…Physical or chemical restraint of laboratory animals is often required for a variety of experimental protocols, including minor and short-term procedures [3]. Rabbits are difficult to anesthetize, and show a wide range of responses [12].…”