The myasthenic syndrome: anaesthesia in a patient treated with 3.4 diaminopyridine.

A case of anaesthesia in a patient with myasthenic syndrome treated with 3.4 diaminopyridine is described. Despite symptomatic improvement and an improved electromyogram (EMG) on treatment, extreme sensitivity to neuromuscular block occurred with vecuronium. Antagonism of block was poor with an anticholinesterase, while oral 3.4 diaminopyridine improved neuromuscular transmission further. A combination of anticholinesterase with aminopyridine may be the antagonistic combination of choice in this condition.