The neuromuscular blocking action of ORG NC 45, a new pancuronium derivative, in anaesthetized patients. A pilot study.

The neuromuscular blocking effects of the new monoquaternary analogue of pancuronium, Org NC 45, have been investigated in anaesthetized patients. In different doses administered as a single i.v. bolus or as an initial bolus followed by several small maintenance doses or by a continuous infusion. Org NC 45 appears to be approximately as potent as pancuronium, but has a more rapid onset of action, considerably shorter duration of action and faster recovery rate than pancuronium. It showed no cumulative effects even after 10 maintenance doses were injected in succession. Doses of 0.08 mg kg-1 provided ideal intubating conditions in 90--95 s. Infusions of Org NC 45 provided much smoother control of neuromuscular blockade than did pancuronium. No cardiovascular side-effects were noted even at the greatest dose (0.12 mg kg-1) used. Org NC 45 has clear advantages over pancuronium and represents a potentially valuable addition to the armamentarium of clinically useful muscle relaxants.