Respiratory Arrest in Myasthenia Gravis With Colistimethate Therapy

A 70-year-old man with myasthenia gravis received a single intramuscular injection of colistimethate sodium (150 mg) for a urinary tract infection. He developed a respiratory arrest with a complete flaccid paralysis three hours later. All muscles but those associated with respiration improved rapidly following intramuscular neostigmine methylsulfate (2 mg) and intravenous edrophonium chloride (10 mg) administration. A combination of ventilation support and anticholinesterase therapy brought about recovery in 11 days. Carbenicillin effectively eradicated the Pseudomonas infection without causing neuromuscular impairment.