What is the recommended treatment for myasthenia gravis?

Treatment of Myasthenia Gravis

First-Line Treatment

Start with pyridostigmine (Mestinon) 30 mg orally three times daily, gradually increasing to a maximum of 120 mg four times daily based on symptom response and tolerability. 1, 2, 3

• Pyridostigmine is FDA-approved and recommended as first-line symptomatic therapy by the Myasthenia Gravis Foundation of America 1, 3
• This acetylcholinesterase inhibitor provides symptomatic relief but does not modify the underlying autoimmune disease process 4
• Approximately 50% of patients, particularly those with ocular myasthenia, may show minimal response to pyridostigmine alone and will require escalation 1
• Sustained-release formulations can reduce dosing frequency and improve quality of life in stable patients 5

Second-Line Treatment: Corticosteroids

For patients with Grade 2 or higher symptoms who have inadequate response to pyridostigmine, initiate prednisone 1-1.5 mg/kg daily with gradual tapering based on symptom improvement. 1, 2, 6

• Corticosteroids demonstrate positive response in approximately 66-85% of patients 1, 6
• The American Academy of Neurology supports corticosteroids as second-line therapy for symptomatic patients 2
• Corticosteroids can be initiated directly in patients presenting with Grade 2 symptoms without requiring a trial of pyridostigmine first 6

Third-Line Treatment: Steroid-Sparing Immunosuppression

Azathioprine should be considered for patients with moderate to severe disease requiring long-term immunosuppression or those needing corticosteroid dose reduction. 1, 6

• Azathioprine is effective for long-term maintenance therapy 6
• Other options for treatment-refractory disease include mycophenolate mofetil, rituximab, and high-dose cyclophosphamide 7
• Efgartigimod alfa-fcab is approved for anti-acetylcholine receptor antibody-positive patients 6

Acute Crisis Management

For myasthenic crisis (Grade 3-4 exacerbations), hospitalize immediately and administer either IVIG 2 g/kg over 5 days OR plasmapheresis for 5 days while continuing corticosteroids. 1, 2, 6

• Both IVIG and plasmapheresis are equally effective for acute exacerbations 1, 2
• Daily neurological assessment and frequent pulmonary function monitoring are essential during crisis 6
• IVIG should NOT be used for chronic maintenance therapy in myasthenia gravis—it is reserved only for acute exacerbations or crisis situations 2

Critical Medications to Avoid

Educate all patients to strictly avoid β-blockers, IV magnesium, fluoroquinolones, aminoglycosides, macrolides, and barbiturates, as these can precipitate myasthenic crisis. 1, 2, 6

• The American Academy of Neurology specifically recommends avoiding these medication classes 1, 2
• Patients should inform all healthcare providers about their myasthenia gravis diagnosis before receiving any new medications 2

Essential Monitoring

Perform regular pulmonary function assessment in all patients with generalized myasthenia gravis, particularly those with respiratory symptoms or more severe disease. 1, 2, 6

• Respiratory compromise is a critical complication requiring close monitoring 1
• Patients should be educated to seek immediate medical attention for worsening dysphagia, dysarthria, diplopia, or increased muscle weakness 2
• Regular neurological follow-up is necessary to adjust treatment based on disease progression 2

Additional Considerations

• Thymectomy should be evaluated in appropriate candidates, particularly younger patients with generalized disease 1
• Approximately 50-80% of patients with initial ocular symptoms may develop generalized myasthenia within a few years, requiring escalation of therapy 1
• Treatment timing should be optimized around medication schedules to maximize functional strength during daily activities 2