Reversal of sedative and clinico-physiological effects of medetomidine by atipamezole in calves

Medetomidine HCl was used in five calves @ 30 fig/kg intramuscularly. The average onset time, down time and time taken to attain lateral recumbency were 4.33+0.47, 5.33±0.47 and 9.33±1.69 min, respectively. Complete muscle relaxation and analgesia were seen for approximately 60 min. Salivation, hyperpnea, bradycardia and initial hypertension followed by hypotension were also noticed. Atipamezole was given 60 min after medetomidine in 1:1 ratio (dose basis) by the intravenous route. The recovery time recorded were 1.33+0.23 min (sitting), 2.83±0.62 min (standing but ataxic) and 3.83+1.02 min (complete recovery) after atipamezole administration. Sedative and analgesic effects of medetomidine were reversed by atipamezole without any complication except for transient arrhythmia.