From the Guidelines
Myositis treatment should prioritize high-dose corticosteroids concurrent with a steroid-sparing agent, such as methotrexate, azathioprine, or mycophenolate mofetil, to minimize morbidity, mortality, and improve quality of life. The treatment approach for myositis, a condition characterized by inflammation of the muscles, should be tailored to the specific needs of the patient, taking into account the severity of the disease and the presence of extramuscular organ involvement 1.
Key Considerations
- For adult patients with idiopathic inflammatory myositis, an initial drug regimen of high-dose corticosteroids concurrent with a steroid-sparing agent is recommended 1.
- For severe myositis, extensive extramuscular organ involvement, or refractory disease, high-dose methylprednisolone in addition to intravenous immunoglobulin, cyclophosphamide, rituximab, or cyclosporine may be used 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.
Treatment Approach
- Corticosteroids like prednisone should be started at 0.5-1 mg/kg/day (usually 40-60 mg daily) for 4-6 weeks, followed by a gradual taper 1.
- Immunossuppressants such as methotrexate (15-25 mg weekly), azathioprine (1-2 mg/kg/day), or mycophenolate mofetil (1000-1500 mg twice daily) may be added for steroid-resistant cases or to reduce steroid dependency 1.
- Physical therapy is essential to maintain muscle strength and prevent contractures.
- Patients should monitor for side effects of medications, including increased infection risk, bone density loss, and gastrointestinal issues.
- Regular blood tests to check muscle enzymes (particularly creatine kinase) help track disease activity 1.
Recent Guidelines
The most recent guidelines recommend a treatment approach that prioritizes high-dose corticosteroids concurrent with a steroid-sparing agent, such as methotrexate, azathioprine, or mycophenolate mofetil, to minimize morbidity, mortality, and improve quality of life 1. However, the 2018 guidelines from the American Society of Clinical Oncology also suggest that prednisone 1 mg/kg or equivalent should be initiated for severe compromise, and consider 1 to 2 mg/kg of methylprednisolone IV or higher-dose bolus if severe compromise 1.
Conclusion Not Applicable
Instead, the focus should be on the key considerations and treatment approach for myositis, prioritizing the most recent and highest quality evidence to minimize morbidity, mortality, and improve quality of life.
From the Research
Definition and Treatment of Myositis
- Myositis is a heterogeneous group of diseases including dermatomyositis, polymyositis, and inclusion body myositis 2.
- The treatment of myositis typically involves the use of glucocorticoids, such as prednisone, often in combination with other immunosuppressive agents like azathioprine or methotrexate 2, 3.
- In cases where patients do not respond to initial treatment, alternative therapies such as intravenous immunoglobulin, rituximab, mycophenolate mofetil, or tacrolimus may be considered 2, 4.
Current Treatment Options
- High-dose glucocorticoids are still considered the first-line treatment for patients with myositis, with the addition of another immunosuppressive agent to better control disease activity and reduce the risk of glucocorticoid-related side effects 3, 5.
- Combining pharmacological treatment with individualized and supervised exercise is also recommended to reduce disease activity and improve muscle performance 3.
- There is some evidence to support the use of rituximab in patients with certain myositis-specific autoantibodies, while other biologic agents are currently being tested in clinical trials 3, 5.
Challenges in Treatment
- The management of myositis presents significant challenges due to the rarity and variability of the disease, as well as the lack of large-scale, randomized controlled trials 6, 4.
- As a result, treatment recommendations vary significantly, and there is a need for multidisciplinary consensus-driven guidelines to reflect the diverse and complex nature of the disease 6.
- More high-quality randomized controlled trials are needed to establish the role of immunosuppressive agents in the treatment of myositis and to identify the most effective treatment strategies for different patient subgroups 4.