What medications exacerbate Myasthenia Gravis (MG)?

From the Guidelines

Medications such as beta-blockers, IV magnesium, fluoroquinolones, aminoglycosides, and macrolide antibiotics should be avoided in patients with myasthenia gravis as they can worsen symptoms. According to the American Society of Clinical Oncology guideline update 1, these medications are known to exacerbate myasthenia gravis and should be reviewed and stopped if possible.

Key Medications to Avoid

• Beta-blockers
• IV magnesium
• Fluoroquinolones
• Aminoglycosides
• Macrolide antibiotics These medications can interfere with neuromuscular transmission at the acetylcholine receptor level, which is already compromised in myasthenia gravis, leading to worsening of symptoms such as increased muscle weakness, difficulty breathing, or swallowing problems 1. It is essential for patients with myasthenia gravis to inform all healthcare providers about their condition before starting any new medication and to report any worsening of symptoms immediately.

From the FDA Drug Label

1. 2 Exacerbation of Myasthenia Gravis Fluoroquinolones, including levofloxacin, have neuromuscular blocking activity and may exacerbate muscle weakness in persons with myasthenia gravis.
2. 8 Exacerbation of Myasthenia Gravis Exacerbation of symptoms of myasthenia gravis and new onset of symptoms of myasthenic syndrome has been reported in patients receiving clarithromycin therapy.

The medications that may worsen myasthenia gravis are:

• Levofloxacin 2
• Clarithromycin 3

From the Research

Medications that Worsen Myasthenia Gravis

• The following medications have been associated with worsening myasthenia gravis symptoms:
  • Ciprofloxacin, levofloxacin, and azithromycin, which are fluoroquinolone and macrolide antibiotics, respectively 4
  • Tobramycin, an aminoglycoside antibiotic, particularly when used in topical form, such as eye drops 5
• These medications can exacerbate myasthenia gravis symptoms, leading to increased frequency and severity of exacerbations, and in some cases, impending crisis or crisis requiring rescue therapy 4
• The use of these medications should be individualized, taking into account the patient's medical history and current condition, as underlying infection may also play a role in exacerbating myasthenia gravis symptoms 4
• Clinicians should be aware of the potential for these medications to worsen myasthenia gravis symptoms and monitor patients closely for signs of exacerbation, particularly when prescribing topical antibiotics like tobramycin eye drops 5