Clinical studies on Org NC 45: comparison with pancuronium

Some actions of Org NC 45 have been compared with those of pancuronium in a study on 50 patients anesthetized with nitrous oxide and narcotic supplements. The train-of-four technique was used to assess the recovery of neuromuscular blockade and its antagonism. Org NC 45 was shown to have a duration of action from injection of the intubating dose (0.1 mg kg-1) to the reappearance of the first twitch response of 23.5 +/- 1.1 min; the corresponding time for pancuronium 0.1 mg kg-1 was 50.5 +/- 3.6 min. Recovery time from the initial incremental dose to the reappearance of the first train-of-four response was 11.6 +/- 0.8 min with Org NC 45 and 31 +/- 4.7 min with pancuronium. No evidence of cumulation was seen following several incremental doses of Org NC 45. The rate of onset of paralysis of adductor pollicis was faster with Org NC 45 than with pancuronium, but the difference did not reach statistical significance. Satisfactory spontaneous recovery from Org NC 45 blockade could be achieved without undue delay. Org NC 45 was shown to produce significantly less tachycardia.