How Myasthenia Gravis Is Treated

Myasthenia gravis (MG) is an autoimmune disease that causes extreme muscle weakness. At one time the disease was disabling and even fatal but that is no longer the case.

MG can be treated with lifestyle measures and medications to relieve and prevent symptoms. Some people with MG need to have a thymectomy—surgery to remove the thymus.

This article describes in detail the various treatments for myasthenia gravis and when each is most likely to be prescribed.

Home Remedies and Lifestyle

There are ways to help prevent and to cope with muscle weakness and other symptoms of myasthenia gravis, such as:

• Taking frequent breaks throughout the day to rest
• Wearing an eye patch to cope with double vision
• Avoiding stress and learning ways to manage it
• Staying out of the heat
  

Prescriptions

Medication is the primary treatment for myasthenia gravis. There are three categories of drugs used: anticholinesterase inhibitors, monoclonal antibodies, and immunosuppressive drugs.

Anticholinesterase Inhibitors

These medications help the nervous system and muscles communicate better. This improves the ability of muscles to contract and boosts strength.

The primary acetylcholinesterase inhibitor used to treat MG is a drug called Mestinon (pyridostigmine). It comes in three forms—a regular tablet, an extended-release tablet, and a syrup.

Side effects of Mestinon include diarrhea, cramping, and nausea, which can often can be prevented by taking it with food.

Less often, an oral form of another anticholinesterase inhibitor called neostigmine is used for MG. This drug more typically is given intravenously after surgery to reverse the effects of general anesthesia on a patient's muscles.

Immunotherapy

Immunotherapy uses medications sometimes referred to immunosuppressants to decrease the number of antibodies released by the immune system. These drugs also reduce inflammation.

Two types of immunosuppressants are used to treat myasthenia gravis:

Glucocorticoids

Glucocorticoids also are known as corticosteroids. The corticosteroid used most often to treat MG is prednisone.

Prednisone is so effective for myasthenia gravis that it frequently is used as a first-line treatment for the disease. In studies, it's been found to start working within a few days and to significantly improve symptoms within a couple of weeks. It can take six months or even longer for prednisone to be fully effective for MG.

The drawback of prednisone and other corticosteroids is they have a number of side effects, some of which can be severe. For this reason, it's important to compare the possible benefits of taking corticosteroids against the potential risks.

Nonsteroidal Immunosuppressants

These medications suppress the immune system but do not have the same types of drawbacks as corticosteroids. They include:

• Imuran (azathioprine), an immunosuppressant often used to treat MG
• Cytoxan (cyclophosphamide), a chemotherapy drug used only for severe myasthenia gravis
• Gengraf and Neoral (cyclosporine), which is used most often to prevent the body from rejecting transplant organs
• Trexall (methotrexate), often used to treat psoriasis and rheumatoid arthritis
• Prograf and Astagraf XL (tacrolimus), a transplant rejection drug
• CellCept (mycophenylate mofetil), an immunosuppressant often used to treat MG
• Vyvgart (efgartigimod), an injectable treatment for MG approved by the Food and Drug Administration (FDA) in 2021
• Ultomiris (ravulizumab), often used to treat certain blood diseases, was recently approved by the FDA in 2022 to treat MG
  

Monoclonal Antibodies

Monoclonal antibodies are man-made proteins that can bind to specific substances in the body. There are two such medications used to treat myasthenia gravis:

• Rituxan (rituximab), used mostly alongside other drugs to treat chronic lymphocytic leukemia, rheumatoid arthritis, and other diseases
• Soliris (eculizumab injection), a relatively new treatment for MG that was approved by the FDA in 2017. It targets a certain part of the immune system called the complement system. Soliris is given by intravenous infusion.

Surgery and Specialist-Driven Procedures

When medication doesn't work well enough to relieve or prevent symptoms of myasthenia gravis, there are other treatments available.

Thymectomy

Thymectomy is surgery to remove the thymus, an organ at the base of the neck that's part of the immune system. Most people with myasthenia gravis have an abnormality of this organ and so removing it may, in some cases, improve symptoms of MG or even cure them altogether.

A large number of people with MG have a thymoma—a tumor of the thymus. Most healthcare providers agree that the thymus should always be removed in these cases.

Plasmapheresis

Plasmapheresis, or plasma exchange therapy, is a type of immunotherapy used when it's important for treatment to take effect quickly. Examples of such cases are a myasthenic crisis, which is when muscles involved in breathing become extremely weak, or when a person is going to have surgery or another procedure that could lead to a myasthenic crisis.

Plasmapheresis is done by gradually removing blood through an intravenous line, separating out the plasma, which contains antibodies, and replacing it with donated plasma that does not contain antibodies. The process is expensive and typically repeated around five times over the course of seven to 14 days.

Complications include arrhythmia, blood cell abnormalities, muscle cramps, and more.

Intravenous immunoglobulin

Intravenous immunoglobulin (IVIG) therapy involves infusions of donated antibodies given over two to five days. It's used for myasthenic crises as well as to help treat myasthenia gravis in general. Treatment typically consists of two to five days of injections. Side effects are usually mild but can include renal failure, meningitis, and allergic reactions.

Prevention

Because it's an autoimmune disease, anything that ramps up the immune system can potentially increase the risk of a myasthenic crisis, with severe worsening that could send someone to the intensive care unit. People with myasthenia should be very cautious before starting any new medication and watch carefully afterward for signs of weakness.

For example, commonly used medications, including antibiotics (such as ciprofloxacin), beta-blockers (such as propranolol), lithium, magnesium, verapamil, and more, can worsen the symptoms of myasthenia gravis.

Summary

There are a number of ways to treat myasthenia gravis, including lifestyle measures and medications to treat muscle weakness. Other drugs can help prevent symptoms and myasthenic crises, in which muscle weakness affects breathing. In some cases, surgery to remove the thymus may be helpful. Other procedures used to treat MG include plasma exchange and immunoglobulin therapy.