What antibiotics are safe to use in patients with Myasthenia Gravis (MG)?

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Last updated: May 9, 2025 • View editorial policy

From the FDA Drug Label

Fluoroquinolones, including levofloxacin, may exacerbate muscle weakness in persons with myasthenia gravis. Avoid levofloxacin in patients with a known history of myasthenia gravis [see Warnings and Precautions (5.2 )]. Fluoroquinolones, including levofloxacin, have neuromuscular blocking activity and may exacerbate muscle weakness in persons with myasthenia gravis. Postmarketing serious adverse events, including deaths and requirement for ventilatory support, have been associated with fluoroquinolone use in persons with myasthenia gravis. Avoid levofloxacin in patients with a known history of myasthenia gravis [see Adverse Reactions (6. 3); Patient Counseling Information (17.3)].

Antibiotics safe with Myasthenia Gravis (MG):

  • Levofloxacin is not safe for patients with MG, as it may exacerbate muscle weakness and has been associated with serious adverse events, including deaths and requirement for ventilatory support [1] [2].
  • No conclusion can be drawn about other antibiotics, as the provided information only pertains to levofloxacin.

From the Research

When it comes to using antibiotics with myasthenia gravis (MG), it is crucial to choose safer options to avoid exacerbating the condition, and the most recent evidence suggests that fluoroquinolones should be avoided due to potential risks, as indicated by a study published in 2021 3. The management of MG involves a range of treatments, including immunosuppressants and acetylcholinesterase inhibitors, as discussed in a review from 2020 4. However, when considering antibiotic use, the focus shifts to minimizing the risk of worsening MG symptoms.

  • Safer antibiotic options for patients with MG include penicillins (such as amoxicillin) and cephalosporins (like cefuroxime), as well as macrolides (e.g., azithromycin), based on general clinical guidelines and the lack of strong evidence against their use in MG patients.
  • It is essential to avoid fluoroquinolones (e.g., ciprofloxacin, levofloxacin) due to their potential to exacerbate MG, as suggested by research 3, and aminoglycosides (like gentamicin) and telithromycin, which can also worsen MG symptoms.
  • If antibiotic treatment is necessary, patients should inform their healthcare provider about their MG diagnosis to ensure appropriate management and monitoring for any signs of worsening muscle weakness, breathing difficulties, or swallowing problems.
  • The reason certain antibiotics can worsen MG is their potential to interfere with neuromuscular transmission, further reducing muscle strength in individuals with the condition, as implied by the pathophysiology of MG discussed in a 2023 review 5.
  • In the event of experiencing worsening symptoms after starting an antibiotic, it is vital to contact the healthcare provider immediately to adjust the treatment plan as needed, ensuring the best possible outcome for the patient's morbidity, mortality, and quality of life.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.