Antagonistic effects of atipamezole and flumazenil on medetomidine-midazolam induced sedation in laboratory pigs.

Antagonistic effects of atipamezole (80, 160 and 240 micrograms/kg, im), and flumazenil (100 micrograms/kg, iv) or atipamezole (80 micrograms/kg) and flumazenil (100 micrograms/kg) on medetomidine-midazolam induced sedation were evaluated in laboratory pigs. Atipamezole at each dose effectively reversed sedation, and the arousal time, standing time and total recovery time were significantly shortened. The optimal action of atipamezole was seen at a dose of 160 micrograms/kg. At this dose recovery from the sedation was quick and smooth, and adverse effects such as hyperactivity or tachycardia were minimal. Flumazenil reversed sedation temporary, but the pigs went back to moderate sedation soon after arousal. The combination of atipamezole and flumazenil most effectively reversed the sedation, however atipamezole (160 micrograms/kg) alone was thought to be practically potent enough to antagonize sedation induced by medetomidine-midazolam in laboratory pigs.