Drug Levels and Effects:

Summary of Use during Lactation:

Limited data indicate that use of neostigmine to treat myasthenia gravis may be acceptable during breastfeeding, although pyridostigmine may be preferred. Monitor newborns because abdominal cramps after each breastfeeding has been reported. Because of its short half-life, single doses of neostigmine to reverse neuromuscular blockade following surgery are unlikely to adversely affect the breastfed infant more than transiently.

Drug Levels:

Maternal Levels.

In a case series of 12 patients with 21 pregnancies in the 1950s and 1960s, the authors could not detect neostigmine in the breastmilk of several of the mothers. However, details of the dosage, timing and assay sensitivity were not stated.[1]

Infant Levels.

Relevant published information was not found as of the revision date.

Effects in Breastfed Infants:

Six infants of mothers treated with neostigmine for myasthenia gravis were reportedly breastfed successfully. However, 1 newborn infant appeared to have abdominal cramps after each breastfeeding, probably caused by neostigmine. Neostigmine could not be detected in the breastmilk of the infant's mother.[1]

Possible Effects on Lactation:

Relevant published information in nursing mothers was not found as of the revision date. In animals, cholinergic drugs increase oxytocin release,[2] and have variable effects on serum prolactin.[3] The prolactin level in a mother with established lactation may not affect her ability to breastfeed.

Alternate Drugs to Consider:



1. Fraser D, Turner JWA. Myasthenia gravis and pregnancy. Proc R Soc Med. 1963;56:379-81. PMID:13085800
2. Clarke G, Fall CH, Lincoln DW, Merrick LP. Effects of cholinoceptor antagonists on the suckling-induced and experimentally evoked release of oxytocin. Br J Pharmacol. 1978;63:519-27. PMID:566601
3. Muller EE, Locatelli V, Cella S et al. Prolactin-lowering and -releasing drugs: mechanisms of action and therapeutic applications. Drugs. 1983;25:399-432. PMID:6133737

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Cholinesterase Inhibitors

  • Parasympathomimetics

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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