Suxamethonium: a new look at pretreatment.

Fifty patients were pretreated with either suxamethonium 10 mg or gallamine 20 mg before an injection of suxamethonium 1 mg kg-1. The effect of the pretreatment upon neuromuscular transmission was monitored by recording the mechanical response of the adductor pollicis muscle to indirect stimulation, using a 2-Hz train-of-four stimulus repeated every 12 s. The pretreatment injection of suxamethonium caused fasciculation in one-quarter of the patients studied. Significant neuromuscular blockade occurred during pretreatment in 16 of the 25 patients investigated. Pretreatment with gallamine 20 mg predictably decreased the efficacy of the intubating injection of suxamethonium, making intubation more difficult. The frequency of muscle pain was similar in both groups.