NEOSTIGMINE AND EDROPHONIUM ANTAGONISM OF MODERATE NEUROMUSCULAR BLOCK INDUCED BY PANCURONIUM OR TUBOCURARINE

Edrophonium and neostigmine are anticholin-esterase drugs usedcommonly to antagonize competitive neuromuscular block. Althoughit has a faster onset of action than neostigmine, edrophoniumis unreliable when used to antagonize deep neuromuscular block.We have compared the antagonist characteristics of these twodrugs when used to antagonize a moderate degree of pancuronium-or tubocurarine-induced neuromuscular block. Forty ASA I orII patients undergoing surgical procedures were allocated randomlyto receive either pancuronium 70 kg^-1 or tubo-curarine 0.5 mgkg^-1, and to receive either edrophonium 0.5 mg kg^-1 or neostigmine0.05 mg kgr^-1. Antagonism was attempted when the first responseto train-of-four (TOF) stimulation recovered spontaneously to25% of the control height. Neuromuscular function was monitoredusing the evoked integrated electromyogram of the first dorsalinterosseous muscle of the hand. Adequate recovery was definedas the achievement of a TOF ratio of 0.70 or greater. Only sevenof 20 patients who received edrophonium demonstrated adequaterecovery 30 min after antagonism. Under the conditions describedin this study, edrophonium 0.5 mg kg7 was less effective asan antagonist than neostigmine 0.05 mg kg^-1. (Br. J. Anaesth.1993; 70: 160–162)