Iraqi Journal of Veterinary Sciences

Abstract

The aim of this study was to evaluate the sedative effect of xylazine alone or as a combination with chloropromazine, and to check the possibility to induce analgesia by the use of sedative (sub analgesic) doses of this combination in chicks. The analgesic ED₅₀ of xylazine (S.C.) and chloropromazine (I.P.) was 0.9756 and 8.598 mg /kg respectively. Depending on Isopolographic analysis, the drug interaction between xylazine and chloropromazine at ratios of 1:1, 0.5:1 and 0.5:0.5 of the analgesic ED₅₀ of xylazine and the sedative ED₅₀ of chloropromazine was synergistic interaction. The injection of sedative (non – analgesic) doses of xylazine (0.5 mg/kg body weight, S.C.) and chloropromazine (4.3 mg/kg body weight, I.P.) together induced deep sedation with excellent analgesia in 100% of the animals in comparison with each drug alone at the same doses. There were no significant differences in glucose levels between the group of xylazine (0.5 mg/kg body weight, S.C.), a group of chloropromazine (4.3 mg/kg body weight, I.P.) or group of xylazine (0.5 mg/kg body weight, S.C.) and chloropromazine (4.3 mg/kg body weight, I.P.) together compared with the control group. Therefore, the combination sedative doses of xylazine and chloropromazine (low doses) can be considered as an ideal mixture for good analgesia in chicks.