Effect of prior administration of suxamethonium on non-depolarising muscle relaxants in the dog.

The depolarising muscle relaxant suxamethonium (0.3 mg kg-1) was administered to six dogs. At 50 per cent return of the neuromuscular activity, as measured by the train-of-four technique, a non-depolarising muscle relaxant was administered. Three drugs, alcuronium (0.1 mg kg-1), gallamine (1.0 mg kg-1) and pancuronium (0.06 mg kg-1) were injected intravenously. At the 50 per cent return of neuromuscular activity, atropine and neostigmine were administered to reverse the neuromuscular block. The duration of action of the three non-depolarising relaxants was reduced by the prior administration of suxamethonium.