Steroid Dosing for Post-Myasthenic Crisis Management
For the first month after a myasthenic crisis, prednisone should be initiated at 0.5-1 mg/kg per day (typically 60-80 mg daily as a single dose) and maintained for 2-4 weeks before beginning a careful taper based on patient response. 1
Initial Steroid Regimen Post-Crisis
Immediate Post-Crisis Phase
- Start prednisone at 0.5-1 mg/kg/day (typically 60-80 mg daily) as a single morning dose
- Maintain this high dose for 2-4 weeks depending on clinical response
- Concurrently initiate a steroid-sparing agent (as these take 3-6 months to reach full efficacy):
- Methotrexate (starting at 15 mg weekly, target 25 mg weekly)
- Azathioprine (target 2 mg/kg ideal body weight)
- Mycophenolate mofetil (starting at 500 mg twice daily, target 1000 mg twice daily)
Steroid Taper Schedule
After the initial 2-4 weeks of high-dose therapy, begin tapering as follows 1:
- Reduce by 10 mg every 2 weeks until reaching 30 mg/day
- Then reduce by 5 mg every 2 weeks until reaching 20 mg/day
- Then reduce by 2.5 mg every 2 weeks until reaching 10 mg/day
- Below 10 mg/day, slow the taper to 1 mg every 2-4 weeks until completed
Monitoring During First Month
- Regular neurological assessments to detect early signs of exacerbation
- Monitor for steroid-induced worsening, which occurs in approximately 42% of patients, particularly in:
- Elderly patients
- Those with severe bulbar symptoms
- Patients with low Myasthenia Gravis Severity Scale scores 2
Special Considerations
Risk of Initial Worsening
- Be vigilant for paradoxical worsening in the first days to weeks of steroid therapy
- Consider hospitalization with capability for ICU transfer during initial high-dose therapy
- Have rescue therapies (IVIG or plasmapheresis) available if needed
Steroid-Sparing Strategies
- Always initiate a steroid-sparing agent concurrently with steroids
- For patients with contraindications to high-dose steroids (uncontrolled diabetes, psychiatric conditions, severe osteoporosis), consider alternative approaches:
- Lower initial steroid doses with more aggressive immunomodulatory therapy
- Earlier use of IVIG or plasmapheresis as adjunctive therapy
Alternative Approaches
- For severe cases with ongoing symptoms, some evidence supports pulse therapy with methylprednisolone 2g IV every five days, which may produce more rapid improvement with less initial worsening 3
- Newer therapies such as efgartigimod may be considered in combination with steroids for refractory cases 4
Medication Precautions
- Avoid medications that can exacerbate myasthenia gravis during the recovery phase:
- Aminoglycosides
- Fluoroquinolones
- Macrolides
- Beta-blockers
- IV magnesium 5
The recommended steroid regimen balances the need for rapid disease control while minimizing the risk of steroid-induced complications. Close monitoring during the first month is essential to detect and manage any exacerbations or adverse effects promptly.