Treatment considerations in myasthenia gravis for the pregnant patient

Q: A 26-year-old female, first time 30 weeks pregnant, and with a known history of Myasthenia Gravis (MG). Pyridostigmine is preffered to be given? - select one

A) Intravenous (IV)

B) Oral

Answer: B

One of the first and mainstay treatments for MG is an acetylcholinesterase inhibitor such as pyridostigmine. Intravenous acetylcholinesterase inhibitors have the tendency to induce uterine contractions and are preferred to be given enterally, either by mouth or nasogastric tube. 

The other required precaution is a higher dose due to increased renal clearance, expanded maternal blood volume, delayed gastric emptying, and frequent emesis. The recommended way to increase the dose is to decrease the interval, or, if needed, to increase the dose and decrease the interval.

If the enteral route fails or labor ensues, IV administration is acceptable.

#ob-gyn

#neurology

References:

1. Norwood F, Dhanjal M, Hill M, et al. Myasthenia in pregnancy: best practice guidelines from a U.K. multispecialty working group. J Neurol Neurosurg Psychiatry 2014; 85:538.

2. Bansal R, Goyal MK, Modi M. Management of myasthenia gravis during pregnancy. Indian J Pharmacol. 2018 Nov-Dec;50(6):302-308. doi: 10.4103/ijp.IJP_452_17. PMID: 30783322; PMCID: PMC6364336.

3. Gilhus NE. Treatment considerations in myasthenia gravis for the pregnant patient. Expert Rev Neurother. 2023 Feb;23(2):169-177. doi: 10.1080/14737175.2023.2178302. Epub 2023 Feb 20. PMID: 36786092.