Mivacurium chloride and myotonic dystrophy.

We describe the successful use of the short-acting, non-depolarizing neuromuscular blocking agent, mivacurium, in a patient with myotonic dystrophy. Increased sensitivity to mivacurium was demonstrated using train-of-four monitoring, with a single dose of mivacurium providing adequate block for 90 min of surgery. Spontaneous recovery appeared prolonged with a recovery index (25-75% T1) of 10 min and a recovery time (5-95% T1) of 30 min. The use of reversal agents and anticholinergic agents was avoided.