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

Ketamine and medetomidine produced chemical restraint for minor procedures in mice. Male mice required 50 mg/kg ketamine, 10 mg/kg medetomidine intraperitoneally (i.p.), and females a higher dose of ketamine (75 mg/kg i.p.). 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.