What Drugs Are Used in Myasthenia Gravis? A Comprehensive Treatment Guide

October 12, 2025 •

4 min read

Myasthenia gravis is an autoimmune disorder that affects an estimated 70-300 people per million globally, causing debilitating, fluctuating muscle weakness. Understanding what drugs are used in myasthenia gravis is crucial, as modern pharmacological options offer significant improvement in symptoms and overall quality of life.

Quick Summary

Myasthenia gravis is managed with several drug classes, including symptomatic cholinesterase inhibitors, chronic immunosuppressants like corticosteroids, and newer targeted biologics that modulate the immune system.

Key Points

Initial Treatment Often Includes Cholinesterase Inhibitors: Medications like pyridostigmine are used first to relieve symptoms by increasing acetylcholine at the nerve-muscle junction.
Immunosuppressants Address the Autoimmune Cause: Corticosteroids (e.g., prednisone) and non-steroidal drugs (e.g., azathioprine) are used for long-term immune suppression.
Newer Targeted Biologics Offer Specific Immune Modulation: FcRn blockers (Vyvgart, Rystiggo) and complement inhibitors (Ultomiris, Zilbrysq) are specific drugs that reduce pathogenic autoantibodies.
Rapid Immunotherapies Are for Acute Crisis: IVIg and plasma exchange are fast-acting, short-term treatments used during severe myasthenic flares or crisis.
MuSK-Positive MG Responds Uniquely: Patients with anti-MuSK antibodies often respond poorly to cholinesterase inhibitors but may benefit from rituximab.
Managing Side Effects is Key to Long-Term Success: Many MG treatments carry significant side effect risks, and ongoing monitoring is necessary to optimize a patient's regimen.

Myasthenia gravis (MG) is a chronic autoimmune disease characterized by a breakdown in communication between nerves and muscles. This occurs when the body's immune system produces abnormal autoantibodies that mistakenly attack components at the neuromuscular junction, most commonly the acetylcholine receptors. This attack disrupts nerve-to-muscle signaling, leading to muscle weakness and fatigue. Treatment strategies are designed to either manage symptoms directly or suppress the underlying autoimmune response.

Symptomatic Relief: Cholinesterase Inhibitors

Cholinesterase inhibitors are often the first line of treatment for MG, providing temporary, symptomatic relief by improving nerve-muscle communication.

How They Work

Targeting Acetylcholine: The enzyme acetylcholinesterase is responsible for breaking down acetylcholine, a neurotransmitter critical for muscle contraction.
Boosting Levels: Cholinesterase inhibitors, or anticholinesterases, block this enzyme, which in turn increases the amount of acetylcholine available at the neuromuscular junction.
Improving Muscle Activation: With more acetylcholine present, nerve signals can be more effectively transmitted to the muscle, leading to improved muscle strength and contraction.

Common Medications

Pyridostigmine (Mestinon): The most frequently used cholinesterase inhibitor for MG, available in regular and extended-release tablets.
Neostigmine (Prostigmin): A short-acting inhibitor, typically used intravenously when pyridostigmine is unavailable.

Side Effects

Common side effects include gastrointestinal upset, diarrhea, nausea, increased saliva, and muscle cramps. A healthcare provider can help manage these symptoms, sometimes by adjusting the dose or prescribing other medications.

Long-Term Management: Immunosuppressants

For most patients, symptomatic treatment alone is insufficient, and long-term immunomodulating drugs are necessary to suppress the immune system and prevent the autoimmune attack.

Corticosteroids

Mechanism: Corticosteroids like prednisone are powerful, broad-spectrum immunosuppressants that reduce the activity of the immune system.
Effectiveness: They can be highly effective, producing marked improvement in a majority of patients, often within weeks to months.
Side Effects: Long-term use is associated with serious side effects, including weight gain, bone thinning (osteoporosis), and an increased risk of infection.
Usage: Due to the side effects, physicians often aim for the lowest effective dose or use other immunosuppressants to minimize steroid dependency.

Non-Steroidal Immunosuppressants

Azathioprine (Imuran): A commonly used immunosuppressant that reduces lymphocyte proliferation. It can take 6–12 months to show effect and is often used as a steroid-sparing agent.
Mycophenolate Mofetil (CellCept): Inhibits lymphocyte production. It is generally well-tolerated but may take several months to work.
Cyclosporine: A calcineurin inhibitor that can produce quicker results than azathioprine but is associated with potential kidney toxicity and other side effects.
Rituximab (Rituxan): A monoclonal antibody that targets B-cells. It is particularly effective for patients with anti-MuSK positive MG and may be used for those with refractory disease.

Modern Targeted Therapies: Biologics

Recent advancements have led to the development of highly specific, targeted biologic therapies that interfere with different parts of the immune response.

Neonatal Fc Receptor (FcRn) Blockers

Mechanism: FcRn blockers bind to the neonatal Fc receptor, preventing it from recycling immunoglobulin G (IgG) antibodies. This promotes the degradation and reduces the level of pathogenic autoantibodies in the blood.
Examples:
- Efgartigimod (Vyvgart): An intravenous or subcutaneous infusion for adults with generalized, anti-AChR antibody-positive MG.
- Rozanolixizumab (Rystiggo): A subcutaneous infusion approved for both anti-AChR and anti-MuSK positive generalized MG.
- Nipocalimab (Imaavy): An intravenous FcRn blocker approved for generalized MG in adults and adolescents.

Complement Inhibitors

Mechanism: These drugs block specific proteins in the complement system, a part of the immune response that contributes to the destruction of the neuromuscular junction.
Examples:
- Eculizumab (Soliris): A first-in-class complement inhibitor for refractory generalized MG.
- Ravulizumab (Ultomiris): A long-acting C5 inhibitor requiring less frequent intravenous infusions.
- Zilucoplan (Zilbrysq): A once-daily, self-administered subcutaneous C5 inhibitor.

Rapid Immunotherapies for Crisis Management

In cases of severe, acute worsening of MG, known as myasthenic crisis, more aggressive, temporary treatments are used to quickly reduce circulating autoantibodies.

Intravenous Immunoglobulin (IVIg): Involves infusing high doses of pooled immunoglobulins from healthy donors. This can temporarily alter the immune system and provide rapid but short-term relief.
Plasma Exchange (PLEX): A procedure that filters the blood to remove the pathogenic autoantibodies.

Comparison of Myasthenia Gravis Drug Classes


Feature	Cholinesterase Inhibitors	Immunosuppressants	Targeted Biologics (FcRn/Complement Inhibitors)	Rapid Immunotherapies (IVIg/PLEX)
Mechanism	Symptomatic; block acetylcholine breakdown.	Suppress broad immune system activity.	Target specific immune pathways (e.g., IgG recycling, complement).	Filter out or modulate autoantibodies.
Onset of Action	Minutes to hours.	Weeks to months (or longer for non-steroidals).	Weeks.	Days.
Duration of Effect	Short-term (hours).	Long-term (chronic use).	Cycles of weeks or months.	Short-term (weeks to months).
Usage	First-line, symptomatic.	Chronic management, often steroid-sparing.	Used for moderate-to-severe disease, often in refractory cases.	Acute crises, rapid control before surgery, or refractory cases.
Key Side Effects	Diarrhea, cramps, nausea, sweating.	Weight gain, osteoporosis, increased infection risk.	Headache, infection risk (esp. meningococcal for C5 blockers).	Headache, flu-like symptoms, circulatory issues, infection risk.

Conclusion: Navigating Treatment Options

The landscape of myasthenia gravis treatment has evolved significantly, moving from broad-based symptom and immunosuppressive management to highly specific targeted therapies. While older drugs like cholinesterase inhibitors remain foundational for symptom relief, and traditional immunosuppressants offer long-term control, the advent of biologics has provided effective options for patients with moderate-to-severe or refractory disease. Decisions about which drugs to use depend on the severity and subtype of MG, individual patient response, and potential side effects. Close collaboration with a neurologist and a specialized care team is essential to tailor a treatment plan that balances efficacy, safety, and long-term patient health.

For more detailed information on specific treatments and clinical research, visit the Muscular Dystrophy Association (MDA)'s resource page on Myasthenia Gravis medical management.

Frequently Asked Questions

The primary first-line medication for myasthenia gravis symptoms is pyridostigmine (Mestinon), a cholinesterase inhibitor. It helps improve muscle strength by increasing the amount of acetylcholine at the nerve-muscle connection.

Corticosteroids like prednisone are powerful immunosuppressants that can be used for long-term management of myasthenia gravis, but their use is carefully monitored due to potential side effects like bone thinning and weight gain.

Targeted biologics work by interfering with specific immune system pathways responsible for the autoimmune attack in MG. For instance, FcRn blockers reduce pathogenic antibody levels, while complement inhibitors block a key immune cascade.

Intravenous immunoglobulin (IVIg) and plasma exchange (PLEX) are rapid immunotherapies used for short-term management of severe myasthenic weakness, such as during a myasthenic crisis.

No. Different medications are used for different MG subtypes (e.g., anti-AChR or anti-MuSK antibody positive) and disease severity. Some advanced biologics are specifically indicated for patients who test positive for particular antibodies.

Newer targeted drugs include FcRn blockers like efgartigimod (Vyvgart), rozanolixizumab (Rystiggo), and nipocalimab (Imaavy), as well as complement inhibitors such as ravulizumab (Ultomiris) and zilucoplan (Zilbrysq).

While some mild cases can be managed with cholinesterase inhibitors alone, most people with myasthenia gravis require a combination of different drug types, including immunosuppressants or biologics, to achieve satisfactory symptom control.

Your doctor might prescribe a non-steroidal immunosuppressant to minimize the long-term side effects of corticosteroids. These drugs, though slower to act, can reduce the need for high-dose steroids over time.