Immunomodulating and immunosuppressive therapy combined with antibiotics and ventilation support, was able to inhibit the occurrence of mortality and reduce morbidity in patients with myasthenia gravis. This treatment can be classified into therapies that can restore muscle strength quickly and therapy which has a slower onset but has a longer effect so as to prevent recurrence.
Short-Term Therapy for Acute State Intervention
a. Plasma Exchange (PE)
The number of patients who got the action in the form of hospitalization and intubation in a long time and tracheostomy, can be minimized due to the dramatic effect of the PE. Primary therapy with PE is the removal of anti-acetylcholine effectively. The response of this therapy is the decrease in antibody titer.
PE most effectively used in situations where short-term therapies that benefit a priority. This therapy is used in patients who are about to enter or is going through a crisis. PE can maximize the power of patients undergoing thymectomy or difficulties patients undergoing postoperative period.
There is no standard regimen for this therapy, but many health centers are replacing about one plasma volume each time therapy for 5 or 6 times daily therapy. Albumin (5%) with a supplemented saline with calcium and sodium may be used for replacement. PE effects will appear in the first 24 hours and can last up to more than 10 weeks.
The main side effect of PE therapy is a shift of fluid during the exchange takes place. Occurred retention of calcium, magnesium, and sodium that can cause hypotension. Thrombocytopenia and changes in various clotting factors may occur in the treatment of recurrent PE. But it is not a condition that can be associated with the occurrence of bleeding, and the provision of fresh-frozen plasma is not required.
b. Intravenous Immunoglobulin (IVIG)
Certain products which 99% is a complement-activating IgG aggregates are relatively safe to be administered intravenously. Mechanism of action of IVIG is not known with certainty, but IVIG is expected to modulate the immune response. Reduction of antibody titer can not be proven clinically, since in most patients there is no impairment of the antibody titer. Effect of treatment with IVIG may appear about 3-4 days after starting therapy.
IVIG is indicated in patients who are also using PE therapy, because both of these therapies has a rapid onset with a duration of only a few weeks. But based on experience and some of the data, there is no similar response between PE with IVIG therapy, so many centers that do not use IVIG as initial therapy for patients in crisis.
IVIG standard dose is 400 mg / kg / day in the first 5 days, followed by 1 g / kg / day for 2 days. IVIG is reported to have clinical advantages of decreased levels of anti-acetylcholine receptor that began 10 to 15 days after infusion done.
The side effects of using IVIG therapy is a great headache and nausea during the infusion, so the drip infusion, become slower. Flu like syndrome such as fever, chills, nausea, vomiting, headache, and malaise can occur in the first 24 hours.
c. Intravenous Methylprednisolone (IVMp)
IVMp given at a dose of 2 grams in 12 hours. If there is no response, the administration may be repeated 5 days later. If still no response, the administration may be repeated 5 days later. About 10 of the 15 patients showed a response to therapy IVMp the second, while the other 2 patients showed a response to the third treatment. Maximum effect is achieved in about 1 week after treatment. Use IVMp the crisis will be considered when other treatments fail or can not be used.
Long-Term Pharmacological Treatment,
Corticosteroid therapy is the most recently used and least expensive for the treatment of myasthenia gravis. Response to corticosteroid treatment began to appear within 2-3 weeks after initiation of therapy. Duration of action of corticosteroids may take up to 18 months, with an average of 3 months.
Corticosteroids have complex effects on the immune system and a definite therapeutic effect on myasthenia gravis is still unknown. Corticosteroids are thought to have an effect on T helper cell activation and proliferation of cells in phase B. T cells and antigen-presenting cells are activated estimated to have a beneficial role in the positioning of corticosteroids on the immune abnormalities in myasthenia gravis. Patients who respond to corticosteroids will experience a decrease of antibody titer.
Corticosteroids is indicated in patients with clinical symptoms that are very disturbing, that can not be controlled by Anticholinesterase. Maximum dose corticosteroid use was 60 mg / day and then performed tapering administration. On the use of doses above 30 mg per day, there will be side effects such as osteoporosis, diabetes, and complications of obesity, and hypertension.
Azathioprine is usually used in patients with myasthenia gravis but relatively controlled with high doses of corticosteroids. Azathioprine can be converted to mercaptopurine, a purine analogue of which has an effect on the inhibition of the synthesis of nucleotides in DNA and RNA.
Azathioprine was administered orally at a dose of 2-3 mg maintenance / kg / day. Patients were given an initial dose of 25-50 mg / day until the dose reached optimal. Azathioprine is a drug that is relatively well tolerated by the body and generally have fewer side effects than other immunosuppressive drugs. Azathioprine response is very slow, with a maximum response obtained in 12-36 months. Recurrence has been reported in approximately 50% of cases, but its use is combined with other immunomodulating drugs.
Cyclosporine affects the production and release of interleukin-2 from T-helper cells. Suppression of T-helper cell activation, effect on antibody production. Initial dose of Cyclosporine administration about 5 mg / kg / day divided into two or three doses. Response to Cyclosporine faster than azathioprine. Cyclosporine can cause side effects such as nephrotoxicity and hypertension.
d. Cyclophosphamide (CPM)
CPM is a alkilating agent that has an effect on B cell proliferation, and indirectly to suppress immunoglobulin synthesis. In theory, CPM has a direct effect on the production of antibodies than other drugs.
e. Thymectomy (Surgical Care)
Thymectomy has been used to treat patients with myasthenia gravis since 1940 and for the treatment of thymoma without myasthenia gravis premises or early 1900. Has done a lot of research on the relationship between the thymus gland with myasthenia gravis events. Germinal center hyperplasia of the thymus is considered as a possible cause of myasthenia gravis is responsible for the incident. Recent research shows that there are other factors that affect the likelihood of thymus development and initiation of immunological myasthenia gravis.
The main purpose of neurology, of thymectomy is achieving a significant improvement of the weakness of patients, reduce the dose of medication that must be taken of patients, and ideally is a permanent cure of the patient.
Many neurologists have the experience to ensure that thymectomy has an important role for the treatment myasthenia gravis, although benefits vary, it is difficult to explain and still can not be proven by rigorous standards. In general, most patients begin to experience improvement within one year after thymectomy and not a few that show a permanent remission (no more weakness, and medicines). Some neurologists believe the amount of remission rate after surgery is between 20-40% depending on the type thymectomy performed. Other neurologists believe that remission depends more and more extensive procedure is between 40-60% of five to ten years after surgery
• Myasthenia Gravis
• Pathophysiology of Myasthenia Gravis
• Clinical Manifestations of Myasthenia Gravis
• Diagnosis of Myasthenia Gravis
MEDICAL BOOKS ABOUT MYASTHENIA GRAVIS
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