DOSE-RESPONSE RELATIONSHIPS FOR NEOSTIGMINE ANTAGONISM OF VECURONIUM-INDUCED NEUROMUSCULAR BLOCK IN ADULTS AND THE ELDERLY

We have studied the dose-response relationship for neostigmine in 36 adult (ages 18-50 yr) and 36 elderly (ages > 70 yr) subjects during antagonism of neuromuscular block induced by vecuronium. All patients received vecuronium 0.08 mg kg −1 and neuromuscular block was monitoredmechanomyo-graphically using the train-of-four (TOF) mode of stimulation. Six patients of each age group were allocated randomly to receive neostigmine 5, 15, 25, 35 or 45 μg kg −1 or saline at 10% recovery of T1 (first response in the TOF). TOF ratios were recorded continuously over the next 10 min and the values at 1-min intervals from 5 min onwards were used to construct the dose-response relationships. There was a significant difference (P