Treatment

Although there's no cure for polymyositis, treatment can improve your muscle strength and function. The earlier treatment is started in the course of polymyositis, the more effective it is — leading to fewer complications.

However, as with many conditions, no single approach is best; your doctor will tailor your treatment strategy based on your symptoms and how well they respond to therapy.

Medications

The most commonly used medications to treat polymyositis include:

  • Corticosteroids. Drugs such as prednisone can be very effective in controlling polymyositis symptoms. But prolonged use of these drugs can have serious and wide-ranging side effects, which is why your doctor may gradually taper the dose of medication down to lower levels.
  • Corticosteroid-sparing agents. When used in combination with a corticosteroid, these drugs can decrease the dose and potential side effects of the corticosteroid. The two most common medications used for polymyositis are azathioprine (Azasan, Imuran) and methotrexate (Trexall). Other medications prescribed for polymyositis include mycophenolate mofetil (CellCept), cyclosporine and tacrolimus.
  • Rituximab (Rituxan). More commonly used to treat rheumatoid arthritis, rituximab is an option if initial therapies don't adequately control your polymyositis symptoms.

Therapy

Depending on the severity of your symptoms, your doctor might suggest:

  • Physical therapy. A physical therapist can show you exercises to maintain and improve your strength and flexibility and advise an appropriate level of activity.
  • Speech therapy. If your swallowing muscles are weakened by polymyositis, speech therapy can help you learn how to compensate for those changes.
  • Dietetic assessment. Later in the course of polymyositis, chewing and swallowing can become more difficult. A registered dietitian can teach you how to prepare easy-to-eat, nutritious foods.

Surgical and other procedures

Intravenous immunoglobulin (IVIg) is a purified blood product that contains healthy antibodies from thousands of blood donors. These healthy antibodies can block the damaging antibodies that attack muscle in polymyositis. Given as an infusion through a vein, IVIg treatments may need to be repeated regularly for the effects to continue.

July 21, 2017
References
  1. Polymyositis and dermatomyositis. Merck Manual Professional Version. http://www.merckmanuals.com/professional/musculoskeletal-and-connective-tissue-disorders/autoimmune-rheumatic-disorders/polymyositis-and-dermatomyositis. Accessed April 13, 2017.
  2. Facts about inflammatory myopathies (myositis). Muscular Dystrophy Association. https://www.mda.org/sites/default/files/publications/Facts_Inflamm_Myopathies_P-199.pdf. Accessed April 13, 2017.
  3. Polymyositis information page. National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/Disorders/All-Disorders/Polymyositis-Information-Page. Accessed April 13, 2017.
  4. Goldman L, et al., eds. Inflammatory myopathies. In: Goldman-Cecil Medicine. 25th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. https://www.clinicalkey.com. Accessed April 13, 2017.
  5. Daroff RB, et al. Disorders of skeletal muscle. In: Bradley's Neurology in Clinical Practice. 7th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. https://www.clinicalkey.com. Accessed April 13, 2017.
  6. Miller ML, et al. Treatment of recurrent and resistant dermatomyositis and polymyositis in adults. http://www.uptodate.com/home. Accessed April 13, 2017.
  7. Miller ML, et al. Initial treatment of dermatomyositis and polymyositis in adults. http://www.uptodate.com/home. Accessed April 13, 2017.
  8. Chang-Miller A (expert opinion). Mayo Clinic, Rochester, Minn. April 23, 2017.