Diphenhydramine overdose during pregnancy: lessons from the past

Am J Obstet Gynecol. 1996 Nov;175(5):1376-7. doi: 10.1016/s0002-9378(96)70059-5.


A primigravid woman was seen for the first time in a disoriented and combative state, with regular, painful uterine contractions. Evaluation revealed a negative illicit drug screen, no evidence of preeclampsia, and a nonfocal neurologic examination. Further workup revealed urinary diphenhydramine levels suggesting drug overdose. This case serves as a reminder of the oxytocin-like effects of diphenhydramine.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Diphenhydramine / poisoning*
  • Drug Overdose
  • Female
  • Humans
  • Oxytocin / pharmacology
  • Pregnancy
  • Uterine Contraction / drug effects*


  • Oxytocin
  • Diphenhydramine