Myasthenia gravis: What does a pharmacist need to know?

Area of Science:

• Pharmacology
• Neurology
• Immunology

Background:

• Myasthenia gravis (MG) is an autoimmune condition affecting the neuromuscular junction, frequently involving acetylcholine receptor antibodies.
• While not highly prevalent, approximately 60,000 individuals in the US have MG, making it a condition pharmacists may encounter.
• Current treatments include immunosuppressants and acetylcholinesterase inhibitors, with limited evidence on optimal efficacy.

Purpose of the Study:

• To educate pharmacists on the pathophysiology and treatment of myasthenia gravis.
• To identify common medications that can induce new-onset or acute exacerbations of MG.
• To provide guidance on managing drug-induced MG exacerbations.

Main Methods:

• Literature review of myasthenia gravis pathophysiology and treatment.
• Analysis of common drug classes and their potential to exacerbate MG.
• Identification of top-prescribed medications associated with MG exacerbations.

Main Results:

• Medications activating the immune system, like immune checkpoint inhibitors, can cause new-onset MG.
• Drugs acting on the neuromuscular junction, including macrolides and fluoroquinolones, can worsen existing MG.
• Other medications such as beta-blockers and magnesium also warrant caution.

Conclusions:

• Myasthenia gravis management requires patient-specific approaches with often limited evidence.
• Pharmacists play a crucial role in identifying and mitigating drug-induced MG exacerbations.
• Awareness of specific drug classes is essential for safe medication use in patients with or at risk for MG.