Relative potency of ORG NC 45, pancuronium, alcuronium and tubocurarine in anaesthetized man.

The relative potency, time-course of action and cardiovascular effects of Org NC 45, a new non-depolarizing neuromuscular blocking agent, have been compared with those of pancuronium, alcuronium and tubocurarine in 64 anaesthetized patients. The relative potency (ED50) to Org NC 45 was 1.74, 3.69 and 8.57 respectively. In doses which caused useful surgical relaxation, duration of action of Org NC 45 was 34%, 39% and 26% that of pancuronium, alcuroniuym and tubocurarine. After administration of repeated doses no cumulation was seen for Org NC 45. The new drug was free from any effect on arterial pressure and heart rate.