Diphenhydramine overdose with intraventricular conduction delay treated with hypertonic sodium bicarbonate and i.v. lipid emulsion

West J Emerg Med. 2014 Nov;15(7):855-8. doi: 10.5811/westjem.2014.8.23407. Epub 2014 Sep 19.

Abstract

Diphenhydramine toxicity commonly manifests with antimuscarinic features, including dry mucous membranes, tachycardia, urinary retention, mydriasis, tachycardia, and encephalopathy. Severe toxicity can include seizures and intraventricular conduction delay. We present here a case of a 23-year-old male presenting with recurrent seizures, hypotension and wide complex tachycardia who had worsening toxicity despite treatment with sodium bicarbonate. The patient was ultimately treated with intravenous lipid emulsion therapy that was temporally associated with improvement in the QRS duration. We also review the current literature that supports lipid use in refractory diphenhydramine toxicity.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Antidotes / therapeutic use*
  • Diphenhydramine / poisoning*
  • Drug Overdose / drug therapy*
  • Drug Overdose / etiology
  • Drug Therapy, Combination
  • Fat Emulsions, Intravenous / therapeutic use*
  • Histamine H1 Antagonists / poisoning*
  • Humans
  • Hypertonic Solutions
  • Male
  • Sodium Bicarbonate / therapeutic use*
  • Tachycardia, Ventricular / chemically induced*
  • Tachycardia, Ventricular / drug therapy
  • Young Adult

Substances

  • Antidotes
  • Fat Emulsions, Intravenous
  • Histamine H1 Antagonists
  • Hypertonic Solutions
  • Diphenhydramine
  • Sodium Bicarbonate