Precautions for glucocorticoid therapy in patients with myasthenia gravis

  Equal daily dose therapy is recommended for diabetic patients to avoid excessive fluctuations in blood glucose levels. When hormones are used at moderate to high doses, improvement in MG symptoms usually occurs within 2-3 weeks. Approximately 50% of patients may experience a transient exacerbation of symptoms early in the course of hormone application (within 7-10 days), usually lasting about 1 week, with approximately 10% of these patients requiring mechanical ventilation for unknown reasons, possibly related to hormone-induced hypofunction of the neuromuscular junction. Both physicians and patients need to be fully estimated and prepared to avoid the occurrence of critical symptoms.  Commonly used hormonal drugs are: (1) Prednisone: No unified understanding has been reached on a reasonable dose of prednisone therapy. Prednisone can be given 10-20 mg/day in a single dose to start, and then increased by 10 mg after 1-2 weeks, and continued for 8-12 weeks after reaching the target dose of 0.75-1 mg/kg, and then gradually reduced to alternate day therapy. For patients with milder symptoms, especially those with simple ocular muscle type, the initial dose can be given 30-50mg/day, which can be increased to 0.75-1mg/kg according to the situation, and then changed to alternate day therapy when the condition improves. (2) High-dose methylprednisolone 500mg/day intravenous injection x 5 days, reduced to 240mg x 5 days, then reduced to 120mg x 5 days, later changed to prednisone 0.75-1mg/kg. this method is suitable for patients who are critically ill and have assisted breathing arrangement.  There is no established guideline for prednisone dose reduction, and the dose is generally reduced gradually after 8-12 weeks of effectiveness, and it takes 1-2 weeks to reflect the recurrence of symptoms after dose reduction. Premature and rapid dose reduction often causes fluctuations in the disease. If the disease worsens during the dose reduction, the previous dosage can be restored. The side effects of glucocorticosteroids are related to the daily dose of the drug, the frequency of administration and the duration of treatment. For different individuals, short-acting glucocorticosteroids with the lowest effective dose, the largest dosing gap and the shortest duration of administration should be given.  Although there is no high-level evidence-based medical data to support the effectiveness of hormone therapy for MG, experience has shown that it is effective. Hormones have many side effects and special attention should be paid to their application, such as weight gain, Cushing’s face, infection, diabetes, hypertension, osteoporosis, and psychosis. Although unavoidable, some measures can be taken to reduce their extent. Patients on a low-calorie, low-carbohydrate, low-sodium diet can reduce weight gain, and taking calcium and vitamin D can reduce bone mineral loss. If the patient develops osteoporosis, treatment with a bisphosphonate compound such as alendronate is indicated. H2 receptor antagonists or proton pump inhibitors are not routinely used unless the patient develops gastric distress. Electrolytes, blood glucose, and blood pressure are checked regularly.