Ericka Wong, MD: I think of pharmacological treatment for myasthenia gravis in several major categories. I divide them into short-acting medications, chronic immunosuppressants, and acute or rapid therapies. For short-acting medications, there are acetylcholinesterase inhibitors, such as pyridostigmine, which treat as symptomatic therapy without altering the underlying disease. Then you have chronic immunosuppressants. Steroids have been a mainstay of this treatment for several decades. It typically takes a few weeks to see clinical benefit, and they work really well, but there are systemic adverse effects: weight gain, cataracts, diabetes, blood pressure, mood changes, the list goes on. These are major reasons why we end up adding other agents to decrease the amount of steroids that we need to use.

The other category that isn't steroids are oral steroid-sparing agents. The most common medications that we think about are mycophenolate or azathioprine. The negatives of these medications are that they take a very long time to see clinical benefit. For mycophenolate, it’s typically 6 to 12 months before we see improvement. For azathioprine, it can be a year or more. That’s something that has been a negative, and we often need to use steroids, IVIG, or plasma exchange to bridge these patients before these medications start to work. Other medications considered chronic immunosuppressants could be B-cell inhibitors like rituximab. This is given through an infusion and is particularly notable for its effectiveness in patients with MuSK antibody-positive myasthenia.

The last category of medications, the rescue medications, are IVIG and plasma exchange typically given in the inpatient setting but can be arranged in the outpatient setting as well. In terms of nonpharmacological treatments, thymectomy has been shown to give long-term stability in generalized acetylcholine receptor antibody-positive patients, so this is something I offer to patients to decrease how much medication they’re on in the long term.

Transcript Edited for Clarity