MIVACURIUM CHLORIDE AND MYASTHENIA-GRAVIS

We describe the successful use of the short-acting, non-depolarizing n euromuscular blocking agent, mivacurium, in a patient with myasthenia gravis taking pyridostigmine 120 mg four times daily. Increased sensit ivity to mivacurium was demonstrated using train-of-four monitoring. A dose of 0.5 times the recommended ED(95) (3.0 mg) resulted in 93% blo ck of T1. Spontaneous recovery was prolonged with a recovery index (25 %-75% T1) of 20.5 min. Residual block was antagonized without difficul ty using neostigmine 2.5 mg. We discuss the relationship between plasm a cholinesterase, acetylcholinesterase and anticholinesterase drugs.