COMPARISON OF THE EFFECTS OF NEOSTIGMINE AND EDROPHONIUM ON THE DURATION OF ACTION OF SUXAMETHONIUM

Rapid sequence induction of anaesthesia necessitating the use of suxam ethonium may occasionally be needed soon after antagonism of neuromusc ular block with anticholinesterase agents. The onset and duration of a ction of 1 mg kg(-1) of suxamethonium was recorded in groups of 10 pat ients each, 5 or 10 min after the administration of edrophonium 1 mg k g(-1) or neostigmine 40 mu g kg(-1) given for the antagonism of atracu rium-induced neuromuscular block. Plasma cholinesterase activity was m easured before, and 5 and 10 min after the administration of the antic holinesterases. A Further 10 patients received suxamethonium 1 mg kg(- 1) without prior atracurium or anticholinesterase administration to se rve as controls. The onset of action of suxamethonium was significantl y prolonged when administered 5 min after both anticholinesterases, co mpared to the control group (P<0.01). Recovery of suxamethonium block was delayed significantly after neostigmine, compared to both the edro phonium and the control groups (P<0.05-0.001). Plasma cholinesterase a ctivity was significantly reduced with the use of neostigmine but not with edrophonium (P<0.001).