Top tips for treatment monitoring in myasthenia gravis

During a roundtable meeting for myasthenia gravis (MG) specialist nurses in October 2023, two presentations were given on MG and treatment mechanisms for the condition. With kind consent from the speakers, we are able to share the core content of those presentations here, as free access education.

Dr Mahjabin Islam, NIHR academic fellow, presented on the interpretation of blood tests. She discussed common adverse events and side effects and effective monitoring across prednisolone, azathioprine, mycophenolate, methotrexate, ciclosporin and rituximab. She detailed information to gather at baseline and aspects of monitoring required for each, both in terms of protocol and timings, and different levels to watch and what they may be indicative of. She suggested the most common issues to watch for with each treatment; weight and renal function were common to almost all and live vaccines are contraindicated in all options. Finally, Mahjabin reviewed safe treatment options in pregnancy, then opened up treatment challenges with case studies.

With prednisolone, as in all steroid use, Mahjabin highlighted the importance of reviewing weight, bone density, renal function, and adrenal insufficiency. She shared the importance of educating patients in potential side effects, and in symptoms of adrenal insufficiency, particularly if they suddenly cease taking their medications, or get recurrent infection. She also suggested standard medications to begin to counteract adverse events in at-risk groups, such as bisphosphonate for those at risk of osteoporosis.

With azathioprine, she highlighted common side effects and how to manage some of these such as reviewing or splitting doses (neutropenia is often dose dependent), offering antiemetics in the case of ongoing nausea, and discussed monitoring practice for both at-risk and non-risk groups.

For mycophenolate, she reminded delegates that this is contraindicated in pregnancy so a pregnancy test is advised in those this is relevant to, and highlighted that flu vaccines are encouraged, and that a severe infection may require terminating treatment.

Methotrexate has a large number of side-effects so these were discussed and the monitoring protocol outlined. Mahjabin noted particularly that liver function can be compromised, that patients will require good oral hygiene and that shortness of breath needs checking for.

Ciclosporin can impact blood pressure and cause high cholesterol, and Mahjabin discussed the process for reducing dosing in these cases.

With rituximab, Mahjabin noted that the drug is unlicensed for neurological conditions and there are no treatment guidelines

An anti-CD-20, she outlined the drug mechanisms and explained how we can monitor whether the treatment is effective, needing to find significant depletion of B-cells within three days of the first infusion. Pregnancy and previous history of viruses like chicken pox need to be checked for before beginning treatment.

For more information, the following references are useful, or to dig more deeply into MG, consider attending our MasterClass in March.

• Narayanaswami P, Sanders DB, Wolfe G, Benatar M, Cea G, Evoli A, Gilhus NE, Illa I, Kuntz NL, Massey J, Melms A, Murai H, Nicolle M, Palace J, Richman D, Verschuuren J. International Consensus Guidance for Management of Myasthenia Gravis: 2020 Update. Neurology. 2021 Jan 19;96(3):114-122. doi: 10.1212/WNL.0000000000011124. Epub 2020 Nov 3. PMID: 33144515; PMCID: PMC7884987.

• Farmakidis C, Pasnoor M, Dimachkie MM, Barohn RJ. Treatment of Myasthenia Gravis. Neurol Clin. 2018 May;36(2):311-337. doi: 10.1016/j.ncl.2018.01.011. PMID: 29655452; PMCID: PMC6690491.

• Sussman J, Farrugia ME, Maddison P, et alMyasthenia gravis: Association of British Neurologists’ management guidelinesPractical Neurology 2015;15:199-206.

Whittam DH, Tallantyre EC, Jolles S, Huda S, Moots RJ, Kim HJ, Robertson NP, Cree BAC, Jacob A. Rituximab in neurological disease: principles, evidence and practice. Pract Neurol. 2019 Feb;19(1):5-20. doi: 10.1136/practneurol-2018-001899.