Dose sparing effects of romifidine premedication for thiopentone and halothane anaesthesia in the dog

Two intravenous doses of romifidine (40 and 80 mu g/kg) and a placebo were compared as premedicants for anaesthesia induced with thiopentone and maintained using halothane in oxygen. Romifidine significantly and linearly reduced the induction dose of thiopentone; placebo-treated dogs required 15.1 +/- 3.6 mg/kg, while dogs treated with 40 mu g/kg and 80 mu g/kg romifidine required 6.5 +/- 1.6 and 3.9 +/- 0.3 mg/kg thiopentone, respectively, Romifidine also significantly and linearly reduced the end tidal halothane concentration necessary to maintain a predetermined level of anaesthesia; placebo-treated dogs required 1.6 +/- 0.3 per cent halothane, while dogs treated with 40 mu g/kg and 80 mu g/kg romifidine required 1.3 +/- 0.4 and 0.8 +/- 0.2 per cent, respectively, Romifidine produced a significant shortening in the recovery from anaesthesia, and the higher dose of romifidine significantly improved the overall quality of anaesthesia.