see also: [[Weakness]] see: [tintinalli - myasthenia gravis](x-devonthink-item://B2FD774F-4883-4856-98A1-9BC4CAE66D9C?page=64), [Rosen - Myasthenia Gravis](x-devonthink-item://73BC7BA1-A819-41CB-A75D-399504B965A3?page=2) > The most significant ED complication of myasthenia gravis is respiratory failure, which is usually precipitated by infection, surgery, or the rapid tapering of immunosuppressive drugs - fluctuating, fatigable weakness of voluntary muscles - especially ocular or proximal limbs - ptosis - improves with rest - improvement of ptosis after edrophonium administration - resp involvement if severe - Check [[FVC]]; normal is 60-70 mL/kg. Need ventilatory support if < 15mL/kg (also used in GBS) # Tx - steroids controversial: - Most patients show improvement with oral corticosteroids in the short term, although high-dose steroids sometimes result first in more weakness before improvement. - Azathioprine or mycophenolate can supplement chronic oral steroid therapy and lower steroid dose - other guidelines say high dose pred 1 - 1.5mg/kg/day is *first line* - 2g/kg IVIG - pyridostigmine 10-120mg/day - neostigmine if isolated ocular disease - plasmaphoresis if available - thymectomy # Drugs to avoid in myasthena Gravis - steroids - anticonvulsants- phenytoin, ethosuximide, trimethadione, mag sulfate, lithium - antimalarials -- cholroqine, quinine - IVF - sidum lactate solution - abx - aminoglycosides, fluroquinolones, sulfonamides, lincomycin, clinda, doxycycline, macrolides, flagyle - psychotropics - chlorpromaize, lithium, amitriptyline, droperidol, haloperidol - antirheumatics - colchicine - cardiovascular - beta blockers, lidocaine, CCBs, magnesium - lidocaine, procaine - narcotics - thyroxine - timolol eye drops - neuromuscular blockers -- especially sux