Medicine for Myasthenia Gravis

Myasthenia gravis (MG) is a chronic autoimmune disorder. MG causes certain muscles to become weak, especially after you use them. There is no cure for MG. But there are drugs to help treat its symptoms and manage the underlying disease.

Sometimes MG symptoms can be unpredictable. Each person’s case can be quite different from the next person’s. This means there is no single treatment or drug that will help everyone who has MG.¹

Your doctor’s goals when treating MG will be to help control your symptoms and improve your quality of life. They will also want to use the lowest drug doses possible to reach those goals. Some people with MG find that their symptoms disappear, or go into remission, for at least some time during treatment.

Types of drugs used

A few medicines, alone or in combination, can help relieve MG symptoms. The best treatment for you will depend on:^1,2

• Your age
• How severe your MG is
• What side effects you have from the drug or drugs
• Whether you are pregnant
• The type of MG antibodies your body produces

Main treatments for MG

Acetylcholinesterase inhibitors are a type of fast-acting drug that improves nerve signals to the muscles. Pyridostigmine (Mestinon^®) is the medicine most often prescribed.^1,2

Steroids (corticosteroids) are a type of hormone used to control MG symptoms quickly. Steroids work by suppressing the immune system. Steroids are used when acetylcholinesterase inhibitors are not enough to control symptoms. Doctors try to avoid long-term, high doses of steroids because these drugs can have many side effects. Prednisone is most often prescribed.^1,2

Immunotherapies are prescribed in moderate to severe MG as an alternative to high doses of steroids or when steroids are not working. Depending on what you need, immunotherapies can make your immune system:^1,2

• Less active (immunosuppressants)
• Act differently (immunomodulators)

Biologics are a type of drug made from living organisms. Biologics used in MG consist of antibodies designed to help suppress the immune system. Different antibody-based biologics are used, depending on the type of MG you have:^1-8

• Eculizumab (Soliris^®) is used to treat refractory MG with anti-acetylcholine receptor (AChR) antibodies.
• Rituximab (Rituxan^®) is used to treat refractory MG with anti-muscle-specific kinase (MuSK) antibodies.
• Ravulizumab-cwvz (Ultomiris^®) is used to treat generalized MG (gMG) with anti-AChR antibodies.
• Vyvgart^® Hytrulo (efgartigimod alfa and hyaluronidase-qvfc) is used to treat generalized MG (gMG) with anti-AChR antibodies.
• Rystiggo^® (rozanolixizumab-noli) is used to treat generalized MG (gMG) with anti-AChR or anti-MuSK antibodies.
• Zilucoplan (Zilbrysq^®) is used to treat generalized myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor (AChR) antibody-positive.

Special considerations

If you are trying to get pregnant or already are pregnant, your doctor may need to change or add to some of the medicines you take to support a healthy pregnancy.

People with MG must also be careful about the other prescription drugs and supplements they take. Some commonly prescribed medicines make MG symptoms worse, such as beta-blockers and some antibiotics and anesthetics.¹

Other treatments

Other treatments for MG may include:¹

• Surgery to remove your thymus gland (thymectomy)
• Plasma exchange (PLEX)
• Intravenous immunoglobulin (IVIG)

Your doctor will also recommend several lifestyle changes. They may also recommend other medicines to improve your quality of life and treat side effects of MG drugs:^1-8

• Antidepressant and antianxiety medicines. These can help improve and regulate your mood if MG is also causing you mental health challenges.
• Antidiarrheal medicines may be prescribed to help manage one of the side effects of acetylcholinesterase inhibitors.
• Bisphosphonates, calcium, and vitamin D supplements. These may be needed to help manage osteoporosis or weakening of the bones caused by chronic steroid use.