Decisions about specific treatment are based on specifics of each patient’s case. Recommended treatments for myasthenia gravis may include various measures that may alleviate symptoms, including anticholinesterase drugs (cholinesterase inhibitors) or alter the disease course, such as immunosuppressive drugs or surgery (thymectomy).
Initial treatment commonly includes the use of cholinesterase inhibitors, which increase muscle strength by preventing the normal breakdown of the neurotransmitter acetylcholine. Pyridostigmine by mouth (orally) is primarily used.
For infants with transient neonatal myasthenia gravis, therapy with cholinesterase inhibitors may be required for only a few days or weeks. In addition, in some cases, physicians may recommend therapy with cholinesterase inhibitors for infants with certain forms of congenital myasthenia.
In many individuals with autoimmune MG, therapy with medications that reduce activity of the immune system (immunosuppressive therapy) also results in improvement. Such agents, which may be combined with cholinesterase inhibitors, may include corticosteroids (e.g., prednisone) or certain other immunosuppressive drugs, particularly azathioprine, mycophenolate mofetil, tacrolimus, and cyclosporine. Generally, corticosteroids result in rapid improvement in the first 2 months of therapy while the other immunosuppressive drugs requiring many months to over a year to be effective. Patients receiving long-term therapy with such medications require ongoing monitoring to help prevent or appropriately treat adverse side effects.
Based on a randomized clinical trial of thymectomy plus prednisone plus prednisone alone, it is generally recommended that thymectomy should be considered for individuals with generalized disease between the ages of eighteen to 65 and have acetylcholine receptor antibodies. Decisions must be individualized for those who have localized involvement of eye muscles, are older than 65 years, or are children (i.e., with autoimmune myasthenia gravis). Thymectomy usually is not recommended for those with ocular myasthenia gravis unless thymoma is detected. In those with autoimmune myasthenia gravis associated with thymoma, recommended treatment is surgical removal of the tumor and the remaining thymus (thymectomy). Many physicians may recommend that thymectomy should be considered in appropriate cases for affected children with autoimmune myasthenia gravis. However, it is important to note that thymectomy is not effective in cases of congenital myasthenia (which does not involve autoimmune abnormalities).
Myasthenic crisis is a medical emergency that requires management in an intensive care unit. Treatment may include emergency respiratory assistance (assisted ventilation); temporary cessation of anticholinesterase therapy to exclude excessive dosage as a possible cause; immediate treatment of possible causative infection with appropriate antibiotic medication or other therapy including plasmapheresis; intravenous immunoglobulin, high dose prednisone, and possibly other therapies.
Plasmapheresis may alleviate symptoms in individuals with autoimmune myasthenia gravis. During this procedure, which is also known as plasma exchange, damaging antibodies are filtered from the blood. By providing a short-term reduction in the levels of anti-ACh receptor antibodies, plasmapheresis may be effective as a temporary therapy in those with severe symptoms or to help treat myasthenic crisis. In addition, plasmapheresis may be recommended to help improve an affected individual’s condition before undergoing surgical removal of the thymus.
Infusion of antibodies (immunoglobulins) obtained from thousands of blood donors and by purification of the fluid portion of the blood (intravenous immunoglobulin IVIG) may also be provided as a temporary therapy before surgical removal of the thymus or for those who experience periods of severe muscle weakness.
Soliris (eculizumab) is for the treatment of generalized myasthenia gravis in patients who are anti-acetylcholine receptor (AchR) antibody-positive. Soliris is extremely expensive and requires intravenous infusion. It is generally limited for treatment of patients who failed other therapies.
Medications, such as particular antibiotics or antiarrhythmic agents, may also aggravate symptoms in individuals with myasthenia gravis and therefore should be avoided or used with caution. . Exacerbation of weakness may occur with various antibiotics, including aminoglycosides, macrolides, and some fluoroquinolones. Patients needing antibiotics should discuss this with their physicians. A complete list of medications to use with caution may be found at myasthenia.org Individuals with myasthenia gravis may have increased sensitivity to the use of certain medications, such as particular anesthetics or muscle relaxants (e.g., succinylcholine, pancuronium). Therefore, this risk must be taken into consideration by surgeons, anesthesiologists, or other health care workers when making decisions concerning potential surgery and use of anesthetics.
Physical therapy may also be recommended to help patients maintain muscle strength and range of motion, but must be performed in a manner to limit any over-exertion Additional treatment for the different forms of myasthenia gravis is symptomatic and supportive.
In 2021, Vyvgart (efgartigimod) was approved to treat adult patients with generalized myasthenia gravis who test positive for the anti-acetylcholine receptor antibody.