ANTAGONIZATION OF XYLAZINE L-METHADONE AN D MEDETOMIDINE L-METHADONE BY ATIPAMEZOLE AND NALOXONE IN THE DOG

In a clinical study comprising 30 canine patients the anaesthetic comb inations xylazine/L-methadone (Group 1) and medetomidine/L-methadone ( group 2) were investigated with respect to the possibility to antagoni ze them with atipamezole and naloxone. Within 15 minutes, complete and in most cases calm antagonization of the sedative, analgetic, cardiov ascular, hypothermic and respiratory depressive effects of the anaesth esia was achieved. A few dogs documented some signs of restlessness du ring the wake-up phase by moaning and waining. One dog from the medeto midine/L-methadone group showed a rebound effect. Atipamezole proved t o be equally potent for antagonization of medetomidine and xylazine, a nd naloxone was a safe opioid antagonist.