While there is not yet a cure for myositis, for some patients, treatments can effectively control and improve symptoms.
Because there are many different symptoms and possible complications, few controlled patient trials and a wide range of reactions to medicines, each person's treatment for myositis is individual. There are commonly used treatment regimens based on experience and case reports:
Corticosteroids: Prednisone, a corticosteroid medicine, is commonly used as a first choice treatment with fairly fast results in polymyositis, juvenile myositis and dermatomyositis. Corticosteroids slow the body's immune system and stop the inflammatory attack on muscle, skin and other body systems. These medicines control the inflammation, ease pain, and increase muscle strength.
The specific dose varies from patient to patient, but doctors tend to prescribe relatively high doses and decrease the dose slowly as the symptoms improve. Doses depend on patient's weight and disease severity. Prednisone can be given orally (as a pill) or intravenously (methylprednisolone given through a needle into a vein). Often, doctors begin patients, especially children, on high-dose intravenous corticosteroids followed by regular oral or intravenous doses, although a recent study showed that oral prednisone is just as effective and has less complications than intravenous prednisone. Doctors closely monitor patients for possible side effects. Some side effects are brittle bones (osteoporosis), cataracts, stomach upset, weight gain, mood swings, and changes in blood sugar. To reduce these side effects, doctors try to taper the dose as quickly as possible while still effectively combating the symptoms. Doctors are increasingly introducing other medicines to allow for a more successful steroid taper.
Doctors sometimes recommend taking corticosteroids every other day rather than every day to lessen the side effects.
Never discontinue or reduce your dose without checking with your physician. Tapering or slowly lowering your dose of corticosteroids is essential to allow your body to begin cortisol production on its own.
Immunosuppressants: Methotrexate and azathioprine are often introduced as secondline medicines or used in combination with prednisone. This allows patients to taper off prednisone more quickly and avoid some of the unwanted effects. Both methotrexate and azathioprine are well-tolerated, but methotrexate tends to work faster. Methotrexate is given orally (as a pill), intravenously or subcutaneously (injected under the skin). Azathioprine is taken orally (by mouth). More and more doctors now treat patients with a combination of methotrexate and prednisone right from the start.
Cyclophosphamide (oral or intravenous) and cyclosporine (oral) are more commonly used in cases where patients exhibit lung complications like interstitial lung disease (ILD) as these are more potent immunosuppressants.
Which immunosuppressants a particular doctor chooses depends on a number of factors, including the patient's response to corticosteroids, medical history and disease severity, as well as the doctor's past experience and personal preference.
Side effects include nausea, cough, fatigue, fever, back pain, abdominal pain, kidney problems, hair loss, and delayed-onset cancers.
Acthar is a preparation of ACTH in 16% gelatin formulation which is used either subcutaneously or intramuscularly in the treatment of polymyositis and dermatomyositis. Acthar is the only FDA approved drug for PM and DM other than corticosteroids. It is a naturally occurring hormone produced in the pituitary gland and has several potential mechanisms as to how it may benefit patients with PM or DM. ACTH causes the release of cortisol from a patient's adrenal glands, thus mimicking the effects of taking corticosteroids by mouth. ACTH also interacts at a number of receptors throughout the immune system and may reduce immune overactivity responsible for causing PM and DM. Although Acthar has FDA approval for treating PM and DM, there is very limited data on the effectiveness of the therapy. Ongoing studies are being performed to evaluate the role for Acthar in the treatment of PM and DM.
Intravenous immune globulin (IVIG): IVIG is a blood product derived from large pools of donated human plasma. IVIG boosts the body's immune system response, and doctors don't know the exact reasons IVIG works in some myositis patients. IVIG is usually reserved for cases resistant to other treatments, and people with inclusion-body myositis typically do not benefit from IVIG unless they have accompanying swallowing problems.
IVIG is given slowly, and the dose depends on the patient's weight. Side effects include backache, headache, fever, chills, general discomfort, and joint pain. Meningitis is possible. Side effects can be related to the rate of infusion, and often slowing this rate relieves unwanted effects. Premedication with Benadryl or Tylenol can also prevent some of these side effects.
IVIG is expensive and typically requires repeated doses.
Biologic agents: Biologic agents inhibit cytokines, key players in myositis inflammation. Most of these agents are monoclonal antibodies, or proteins targeting tumor necrosis factor-alpha, B cells and T cells. These medicines provide a more targeted therapy now being studied in clinical trials for myositis.
Anti-TNF agents suppress tumor necrosis factor proteins that are associated with inflammation and include etanercept (Enbrel), adalimumab (Humira) and infliximab (Remicade). Etanercept and adalimumab are subcutaneous injections; infliximab, is an intravenous injection.
Rituximab (Rituxan) targets B cells, or lymphocytes of the immune system that produce antibodies that attach to a specific antigen to help destroy it. B cells play a role in the inflammation of myositis. Rituximab is given intravenously. A large, mutli-center study of rituximab in myositis (RIM) was statistically inconclusive, but found that rituximab shows promise for the treatment of myositis.
Alemtuzumab (Campath 1H) is directed against T cells, another type of lymphocyte that attacks antigens directly. Alemtuzumab is given intravenously and is still restricted to research study participants.
Since these agents are fairly new in treating myositis, doctors monitor patients closely for any side effects. Some reported include abdominal pain, diarrhea, loss of energy, chills, dizziness, frequent urination, and headache.
These treatments are expensive and often are not covered by insurance.
More than medications: Many doctors recommend a holistic approach to treatment,
In orbital myositis, remission may occur without any therapy, but systemic corticosteroids are the accepted therapy in the acute phase. A common course of treatment is systemic corticosteroids at doses of 60 to 120 mg prednisone a day for two weeks, with subsequent tapering over weeks to months.
Prompt treatment is associated with dramatic improvement in symptoms, and a reduced risk of muscle fibrosis and recurrence. Treatment with nonsteroidal anti-inflammatory drugs has also had some success, but these drugs are not considered as effective as corticosteroids.
There are also cases of treatment with immunosuppressive drugs, but there are too few case reports to make recommendations on their utility. Patients with multiple recurrences, or those unresponsive to therapy, should have biopsy samples taken to rule out any other hematological malignancy.
Radiotherapy may be used in patients who fail to respond to steroids or have a rapidly progressive course. Several studies have reported favorable outcomes with radiation therapy, indicating that radiation therapy remains a viable treatment option for idiopathic orbital inflammation.
In patients who are refractory to both corticosteroids and radiotherapy, anecdotal reports have suggested the use of chemotherapeutic agents such as cyclophosphamide and cyclosporine Methotrexate and intravenous immunoglobulin have similarly been found to be effective in treating idiopathic orbital inflammation that did not respond to steroids.
Despite the initial favorable response to steroid therapy, relapses and recurrent inflammation are common and often complicate the clinical course and treatment. Orbital myositis may turn into a recurrent or chronic disease, requiring repeated courses or maintenance of corticotherapy.
In one study of16 patients, all patients responded to initial treatment with oral corticosteroids or other anti-inflammatory drugs. Of these 16 patents, nine had one or more recurrences, which responded to repeated courses of corticosteroids, other anti-inflammatories or radiation.
Researchers concluded that orbital myositis responds well to oral corticosteroids, but recurs in 50% of the cases.
Updated February 2014