Neuromuscular blocking effects of vecuronium and pancuronium during halothane anaesthesia

The neuromuscular blocking properties of vecuronium (Org NC 45) and pancuronium were compared in 40 patients during halothane anaesthesia. Onset time was found to be dose-dependent, but no significant difference was found between the two drugs. The duration of action of vecuronium was significantly shorter than pancuronium. Times to 90% recovery of twitch height following vecuronium 0.03 mg kg-1 and 0.057 mg kg-1 were 32.0 min and 44.9 min, respectively, compared with 72.9 min and 124.7 min following equipotent doses of pancuronium (0.042 mg kg-1 and 0.08 mg kg-1). Recovery indices following both doses of vecuronium (10.0 min and 11.8 min) were significantly shorter than after pancuronium (31.0 min and 46.9 min). The reversal times of vecuronium (times from 10% to 90% twitch height recovery) were significantly shorter than those of pancuronium (7.9 min and 7.3 min, respectively, compared with 17.1 min and 17.7 min).