Mestinon is an acetylcholinesterase inhibitor, just like edrophonium but longer acting. Mestinon increases availability of ACh at the receptor site, thereby increasing strength. This is considered symptomatic treatment only, since it does not affect the underlying cause or course of the disease. The usual maximum dose is 60mg q4 hours and the typical starting dose is 30mg q6 hours. Chronic high doses should be avoided, by giving drug holidays if necessary.
Immunosuppression is the mainstay of treatment.
Acute treatment is given for myasthenic crisis or active disease which is severe and not responding to more chronic therapies. Plasmapheresis is the primary means of acute therapy. Plasmaphersis therapy consists of filtering antibody proteins out of the blood, thereby removing the offending anti-AChR antibodies. Initiating steroid therapy must be done carefully as it can cause increased weakness for 2-3 days. Cyclosporin A is used second line in cases of Imuran failure.