From the Guidelines
All patients with myasthenia gravis flare should undergo a thorough workup and intervention, given the potential for progressive MG to lead to respiratory compromise, as stated in the 2021 ASCO guideline update 1. The workup for a myasthenia gravis flare should begin with a thorough clinical assessment to confirm the diagnosis and determine severity, focusing on muscle strength, fatigability, and respiratory function.
- Initial evaluation includes a detailed neurological examination
- Laboratory tests should include acetylcholine receptor antibodies (AChR-Ab), muscle-specific kinase antibodies (MuSK-Ab), and lipoprotein receptor-related protein 4 antibodies (LRP4-Ab)
- Complete blood count, comprehensive metabolic panel, thyroid function tests, and inflammatory markers should be ordered to identify potential triggers or comorbidities. According to the 2021 ASCO guideline update, inpatient admission may be appropriate at all grades of myasthenia gravis flare 1.
- For G2 symptoms, which include some symptoms interfering with activities of daily living (ADLs), mild generalized weakness, or ocular symptoms, hold immune checkpoint inhibitors (ICPi) and consider resuming only if symptoms resolve and steroid taper is completed 1.
- Treatment for G2 symptoms typically involves pyridostigmine starting at 30 mg PO three times a day, with gradual increase to a maximum of 120 mg PO four times a day as tolerated 1, as well as administering corticosteroids, such as prednisone 0.5 mg/kg orally daily 1. For more severe symptoms (G3-4), which include limiting self-care, weakness limiting walking, dysphagia, facial weakness, respiratory muscle weakness, or rapidly progressive symptoms, permanently discontinue ICPi, admit the patient, and consider ICU-level monitoring 1.
- In addition to the treatments for G2 symptoms, initiate IVIG 2 G/kg IV over 5 days or plasmapheresis 1, and consider adding rituximab if refractory to IVIG or plasmapheresis.
- Frequent pulmonary function assessment and daily neurologic review are also crucial in managing severe myasthenia gravis flares 1.
From the FDA Drug Label
Pyridostigmine bromide is useful in the treatment of myasthenia gravis. The FDA drug label does not answer the question.
From the Research
Workup for Myasthenia Gravis Flare
- The workup for a myasthenia gravis flare typically involves evaluating the severity of the flare and identifying any potential triggers or underlying causes 2.
- A clinical diagnosis of myasthenic crisis is defined by respiratory failure caused by exacerbation of myasthenia gravis, and can be differentiated from other neuromuscular junction diseases by the presence of normal reflexes, normal sensation, lack of autonomic symptoms, lack of fasciculations, and worsening weakness with repetitive motion 2.
Treatment Options
- Treatment for myasthenia gravis flare may include intravenous immunoglobulin (IVIg) or plasmapheresis, which have been shown to be effective in improving symptoms and reducing the need for mechanical ventilation 3, 4.
- Acetylcholinesterase inhibitors, such as pyridostigmine, may also be used to treat myasthenia gravis, although their use during a crisis is generally avoided due to the risk of worsening symptoms 2, 5, 6.
- Corticosteroids may be used to treat myasthenia gravis, but their use during a crisis is generally avoided due to the risk of worsening symptoms 2.
Management of Myasthenic Crisis
- The management of myasthenic crisis typically involves providing respiratory support, either through noninvasive positive-pressure ventilation or mechanical ventilation, and treating any underlying infections or other triggers 2.
- IVIg or plasmapheresis may be used to treat myasthenic crisis, and have been shown to be effective in improving symptoms and reducing the need for mechanical ventilation 3, 4.
- Acetylcholinesterase inhibitors may be restarted prior to extubation, but caution should be observed due to the risk of complications such as cardiac arrhythmia and pneumonia 5.