Reversible cholinesterase inhibitor used for treatment of Myasthenia Gravis (see specific info). It is excreted into breast milk at undetectable levels (Skoglund 1978) or clinically non-significant (Hardell 1982, Djelmis 2002) without harmful effects having been observed in infants whose mothers were treated (Skoglund 1978, Hardell 1982). Plasma levels in such infants were undetectable (Hardell 1982). Because of a low oral bioavailability it seems even more unlikely the pass to the infant’s plasma through ingested breastmilk, except in preterm infants and immediate neonatal period, when there may be an increased intestinal permeability. American Academy of Pediatrics: medication usually compatible with breastfeeding.WHO 2002 List of Essential Medicines: compatible with breastfeeding.