Parasympathomimetic (Cholinergic)
PREGNANCY RECOMMENDATION: Limited Human Data—No Relevant Animal Data
BREASTFEEDING RECOMMENDATION: No Human Data—Probably Compatible
PREGNANCY SUMMARY
Physostigmine is rarely used in pregnancy. No reports linking its use with congenital defects have appeared.
FETAL RISK SUMMARY
Physostigmine is an anticholinesterase agent, but it does not contain a quaternary ammonium element. It crosses the blood–brain barrier and should be expected to cross the placenta (1). Crossing to the embryo–fetus would be consistent with its relatively low molecular weight (about 275).
One report described the use of the drug in 15 women at term to reverse scopolamine-induced twilight sleep (2). Apgar scores of 14 of the newborns ranged from 7 to 9 at 1 minute and 8 to 10 at 5 minutes. One infant was depressed at birth and required resuscitation, but the mother had also received meperidine and diazepam. No other effects in the infants were mentioned.
Transient muscular weakness has been observed in about 20% of newborns of mothers with myasthenia gravis (3–5). The neonatal myasthenia is caused by transplacental passage of anti-acetylcholine receptor immunoglobulin G antibodies (5).
BREASTFEEDING SUMMARY
No reports describing the use of physostigmine during human lactation have been located. The relatively low molecular weight (about 275) suggests that it will be excreted into breast milk. The effect of this exposure on a nursing infant is unknown.
References
1.Taylor P. Anticholinesterase agents. In Gilman AG, Goodman LS, Gilman A, eds. The Pharmacological Basis of Therapeutics. 6th ed. New York, NY: Macmillan, 1980:100–19.
2.Smiller BG, Bartholomew EG, Sivak BJ, Alexander GD, Brown EM. Physostigmine reversal of scopolamine delirium in obstetric patients. Am J Obstet Gynecol 1973;116:326–9.
3.McNall PG, Jafarnia MR. Management of myasthenia gravis in the obstetrical patient. Am J Obstet Gynecol 1965;92:518–25.
4.Blackhall MI, Buckley GA, Roberts DV, Roberts JB, Thomas BH, Wilson A. Drug-induced neonatal myasthenia. J Obstet Gynaecol Br Commonw 1969;76:157–62.
5.Plauche WC. Myasthenia gravis in pregnancy: an update. Am J Obstet Gynecol 1979;135:691–7.