Treatment of myasthenia gravis: medications and other measures

Cholinesterase inhibitors and immunosuppressants are the mainstay of treatment for myasthenia gravis. These are drugs that suppress immune reactions, including reactions directed against the body's own tissues.

If the symptoms of the disease are resistant to these basic treatments or the condition is urgent (for example, myasthenic crisis), plasmapheresis or intravenous immunoglobulins may be used.

Four principles of MG treatment:

1. Symptomatic treatment

Acetylcholinesterase inhibitors increase the level of acetalcholine in the neuromuscular disc by preventing its enzymatic degradation. For example, preparations such as neostigmine or pyridostigmine are used.

Pyridostigmine bromide is better in terms of effect because it has a longer duration.

Some patients may experience stomach and intestinal upset when treated with this medicine. This is due to an intolerance to bromide. In this case, treatment may be changed to ambenonium chloride.

Patients with positive anti-MuSK antibodies react poorly to these drugs and therefore higher doses are also required.

2. Immunosuppressive therapy

These drugs suppress immune processes in the body. They are indicated in patients who remain symptomatic after treatment with pyridostigmine.

Glucocorticoids (prednisone, prednisolone and methylprednisolone) and azathioprine are the first-line immunosuppressants used in the treatment of this disease.

Second-line drugs include cyclosporine, methotrexate, mycophenolate, cyclophosphamide and tacrolimus. They are used if the patient does not respond to treatment or has contraindications to treatment, such as intolerance to first-line drugs.

Recently, various monoclonal antibodies, such as rituximab and eculizumab, have been developed for the treatment of resistant MG.

3. Intravenous immunoglobulins (IVIG) and plasmapheresis

IVIGs are drugs whose main active ingredient is IgG antibodies. These IgG antibodies occupy receptors to which "harmful" autoantibodies can no longer bind.

Thus, they quickly relieve the symptoms of the disease, especially in the acute phase, for example in a myasthenic crisis.

Plasmapheresis is a therapeutic method in which blood plasma is separated from the blood cells and then 'purified'. The plasma contains autoantibodies, which are thus eliminated from the patient's body relatively quickly and effectively.

In one plasmapheresis, about 3-5 litres of plasma are filtered and about 70% of the autoantibodies are removed.

This type of treatment is recommended as a preparation in the perioperative period to better stabilize the patient before surgery.

It is also a treatment deployed in sudden myasthenic crisis. It is used especially in patients who are resistant to immunosuppressants.

4. Thymectomy

This is a surgical procedure in which a thymoma is removed from the patient's chest cavity.

It is indicated in cases where there is a proven association between MG and thymoma, in the case of non-thymomatous MG with negative antibodies to AChR, especially in patients aged 15 to 50 years, and in the case of seronegative non-thymomatous MG.