Drugs to avoid or use with caution in patients with myasthenia gravis*

HMG-CoA: hydroxymethylglutaryl coenzyme A; IVIG: intravenous immune globulin.

* This is not a complete list of all drugs that may, in individual patients, adversely affect neuromuscular transmission and worsen myasthenia gravis symptoms. If such drugs are used, they should be administered cautiously with appropriate monitoring. Refer to UpToDate for additional information.

¶ Response to neuromuscular blocking agents is unpredictable in patients with myasthenia. Use only when necessary, guided by neuromuscular monitoring.

Δ Reserve use for hospitalized patients when alternative agents are unavailable.

◊ Glucocorticoids at high dose may cause transient worsening of symptoms during first one to two weeks of treatment. They should be used with caution; when administered for hospitalized patients in myasthenic crisis, concurrent plasmapheresis or IVIG should be coadministered.

§ Increased weakness in MG has been reported with use of older iodinated contrast agents; modern iodinated contrast agents appear generally safe.

¥ Intravenous administration (eg, with magnesium sulfate, magnesium chloride) is relatively contraindicated due to significant inhibitory effect on acetylcholine release.