From the Guidelines
The initial treatment for autoimmune myopathy should involve high-dose corticosteroids concurrent with a steroid-sparing agent, such as methotrexate, azathioprine, or mycophenolate mofetil. This approach is based on the most recent and highest quality evidence available, which suggests that combining corticosteroids with a steroid-sparing agent can effectively reduce inflammation, prevent further muscle damage, and minimize the side effects associated with long-term steroid use 1.
Key Considerations for Treatment
- High-dose corticosteroids, such as prednisone, should be initiated at a dose of 0.5-1 mg/kg/day (usually 40-60 mg daily) to rapidly reduce inflammation and prevent muscle damage.
- A steroid-sparing agent, such as methotrexate (15-25 mg weekly), azathioprine (2-3 mg/kg/day), or mycophenolate mofetil (1-1.5 g twice daily), should be added within the first few weeks of treatment to reduce the need for long-term steroid use and its associated side effects.
- Regular monitoring of muscle strength, creatine kinase levels, and medication side effects is essential to assess treatment response and guide therapy adjustments.
- Physical therapy should also be initiated early to maintain muscle strength and prevent contractures.
Additional Treatment Options
- For patients with severe or rapidly progressive disease, intravenous methylprednisolone pulse therapy (1000 mg daily for 3-5 days) may be used before transitioning to oral steroids.
- Other immunosuppressive agents, such as cyclophosphamide, rituximab, or cyclosporine, may be considered for patients with refractory disease or extensive extramuscular organ involvement 1.
- Novel biomarkers of disease activity, such as interleukin 6 and type 1 interferon-regulated genes, may serve as indicators of disease activity in adult and juvenile myositis 1.
Monitoring and Adjustments
- Patients should be closely monitored for signs of treatment response, including improvements in muscle strength and reductions in creatine kinase levels.
- Medication side effects, such as gastrointestinal adverse effects, should be regularly assessed and managed accordingly.
- Treatment adjustments, including tapering of corticosteroids, should be made based on individual patient response and disease activity 1.
From the Research
Initial Treatment for Autoimmune Myopathy
The initial treatment for autoimmune myopathy typically involves the use of glucocorticoids, such as prednisone, as the first-line therapy 2, 3, 4, 5.
- The use of high-dose daily oral corticosteroids is common in the treatment of idiopathic inflammatory myopathies (IIM) 3.
- Pulse dose intravenous methylprednisolone (IVMP) has been used for serious or refractory cases of IIM, showing marked improvement in clinical and biochemical outcomes 3.
- For patients who do not respond adequately to corticosteroids, immunosuppressive drugs such as azathioprine, mycophenolate, methotrexate, or cyclosporine may be used as second-line therapy 2, 4, 6.
- Intravenous immunoglobulin (IVIg) is also considered a second-line therapy, particularly for patients with dermatomyositis, polymyositis, or necrotizing autoimmune myopathy (NAM) 2, 4, 6.
Special Considerations
- Inclusion body myositis (IBM) is generally resistant to most therapies, but early initiation of therapy may be helpful in some cases 2, 4.
- The treatment of systemic autoimmune myopathies (SAM) should include an early rehabilitation program with strength-building and aerobic exercises, as well as patient education 5.
- There is no specific period determined for the suspension of glucocorticoid and immunosuppressive drugs when individually evaluating patients with SAM 5.