Physostigmine’s effect on diminished fetal heart rate variability caused by scopolamine, meperidine and propiomazine

The treatment of maternal and fetal anticholinergic toxicity with physostigmine

“…This ability to cross the blood-brain barrier suggests that it can to cross the placenta as well [3]. Boehm et al [5] described using physostigmine to reverse the effects of therapeutic administration of anticholinergic agents in gravid patients, and in our overdose case presented above. No reports linking physostigmine to congenital defects have appeared, and it is rated FDA Risk Factor C [17].…”

“…Antihistamines block acetylcholine at muscarinic receptors resulting in anticholinergic signs and symptoms, including tachycardia, mydriasis, dry and flushed skin, urinary retention, agitation, delirium, and hallucinations [2]. Although there are no reports in the literature of antihistamine toxicity in a fetus due to maternal overdose, evidence suggests that diphenhydramine crosses the placenta, and therefore may cause toxic effects on the fetus, including tachycardia and loss of beat-to-beat variability [4,5]. Placental transfer of diphenhydramine occurs in sheep [3].…”

“…Antihistamines also appear to cross the placenta, possibly causing anticholinergic toxicity in the fetus, manifesting primarily as tachycardia [3]. Physostigmine, the principal antidote for severe anticholinergic toxicity, crosses the placenta [4,5]. Following a report of two cases published in 1980 that attributed adverse outcomes to physostigmine used in tricyclic antidepressant overdose, its overall use, even in the toxicology community, declined [6,7].…”

Are there teratogenic risks associated with antidotes used in the acute management of poisoned pregnant women?

“…Case reports describing adverse events possibly related to naloxone use near delivery for reversal of opiate effects, but not overdose, have been published (Schoenfeld et al, 1987; Sun, 1998). The effect of physostigmine during pregnancy has been described in two studies, but not for overdose (Smiller et al, 1973; Boehm et al, 1977). In the first study, physostigmine was used in 15 pregnant women at term to reverse the effect of scopolamine (Smiller et al, 1973).…”

“…One of the infants was depressed, but had received meperidine and diazepam as well; there was no fetal bradycardia. In the second study, the effect of physostigmine on diminished heart rate variability caused by scopolamine, meperidine, and propiomazine was evaluated (Boehm et al, 1977). In 17 pregnant women at term, physostigmine reversed the diminished heart rate variability caused by scopolamine (Boehm et al, 1977).…”