Myasthenia gravis management: Your medication guide

Last updated May 1, 2024, by Marisa Wexler, MS
Fact-checked by Patrícia Silva, PhD

Although there isn’t a cure for myasthenia gravis (MG) yet, a number of therapies are available to help manage the disease and its symptoms. There are a few different types or classes of medication that may be used to treat MG. Each has a different way of working and method of administration.

Deciding which medicine(s) to use depends on the specific situation. Because MG affects everyone differently, there isn’t any one type of myasthenia gravis medication that is best in all circumstances. For some patients with milder disease, medication may not even be necessary.

Work collaboratively with your healthcare team to understand the risks and benefits of the different types of therapies and make treatment decisions.

Medications available for MG

Myasthenia gravis is mainly caused by self-targeting antibodies. These antibodies interfere with the chemical signaling that nerve cells use to control muscle movement, leading to muscle weakness.

Medications for MG treatment help counteract the impact of the disease on the body by lessening the intensity of the autoimmune attack and/or increasing the strength of the signals that travel from the nerve to the muscle cells.

The type of MG also determines what is the most appropriate therapeutic approach. For example, ocular MG treatment commonly aims to relieve eye-related issues.

Medications specifically used to treat MG include anticholinesterases, complement inhibitors, and FcRn blockers.

Other anti-inflammatory medications, including corticosteroids and nonsteroidal general immunosuppressants, are sometimes used to help manage the disease, but these therapies are thought to work more broadly by decreasing immune activity rather than targeting specific biological mechanisms that drive the disease.

Anticholinesterases

Purpose: Improves muscle strength

How it’s administered: Usually given orally, although injectable versions such as intravenous (into-the-vein) infusions or intramuscular (into-the-muscle) injections are an option for people who cannot take oral meds or to use during a severe MG-related health issue including a myasthenic crisis.

How it works: Nerve cells normally release a signaling molecule called acetylcholine to trigger muscle cells to contract. In most people with MG, disease-driving antibodies target the acetylcholine receptor, reducing the intensity of acetylcholine signals from nerve cells.

Anticholinesterases block the activity of an enzyme that normally breaks down acetylcholine, thereby helping to increase acetylcholine levels and muscle strength.

Complement inhibitors

Purpose: Lessens the intensity of the autoimmune attack that drives MG

How it’s administered: Some complement inhibitors are given as an intravenous infusion treatment by a slow drip into the bloodstream, which is usually done in a hospital or medical center. Others are administered by subcutaneous (under-the-skin) injection, which, with the right training, can be given at home by patients or caregivers.

How it works: MG-driving antibodies trigger a group of defense proteins called the complement cascade — which is part of the body’s immune system. The complement-driven immune attack is one of the main ways that disease-driving antibodies damage muscles in MG. Complement inhibitors try to stop the activation of the complement cascade, and therefore reduce the autoimmune attack that drives the disease.

These therapies are generally quite effective at controlling MG disease activity. But because they block the complement cascade — an important part of the immune system that normally helps fight off infections — these therapies are associated with an increased risk of infections, among other potential side effects.

FcRn blockers

Purpose: Lessens the intensity of the autoimmune attack that drives MG

How it’s administered: Some FcRn blockers are given as an intravenous treatment, while others are given by subcutaneous injection.

How it works: FcRn, short for neonatal Fc receptor, is a protein that normally helps to stabilize certain antibodies in the bloodstream. FcRn blockers work by inhibiting the FcRn protein and, consequently, reduce the levels of all antibodies, including those that drive MG. In doing so, they help lessen the intensity of the autoimmune attack that causes the disease.

Similar to complement inhibitors, FcRn blockers are generally quite powerful at controlling MG. But because they reduce the activity of an important part of the immune system, one of their side effects is an increased risk of infection.

Myasthenia Gravis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.