Common Pharmacologic Precipitants of Myasthenic Crisis

Patients with myasthenia gravis  may be seen in the emergency department for symptoms that are  not related to their MG, such as an upper respiratory tract infection or chest pain.

Physicians should be careful in prescribing new medications to patients with MG, as that can precipitate a myasthenic crisis (and therefore cause significant morbidity and mortality). Below is a list of medications that are commonly implicated; an extensive list can be found at www.myasthenia.org/docs/MGFA_medicationsandmg.pdf)

  • Iodinated IV contrast
  • Fluoroquinolones
  • Aminoglycosides
  • Macrolides
  • IV magnesium replacement
  • Beta blockers (metoprolol and labetalol)