Rapid Review: Anticholinergic Toxidrome

Anticholinergic Toxidrome

• PE will show hyperthermia, tachycardia, mydriasis, and dry skin
• Treatment is supportive care alone or in combination with antidotal therapy with physostigmine
• Comments: Classes of medications with anticholinergic properties include antihistamines, tricyclic antidepressants, and sleep aids
• Mnemonic: “Mad as a hatter” (AMS), “blind as a bat” (mydraisis), “red as a beet” (flushed skin), “hot as a hare”(anhydrosis), and “dry as a bone” (dehydration)

Sample question:

A 4-year-old girl presents to the ED because of possible ingestion. She was unattended for several minutes when she went through her grandmother’s bag containing bottles of bethanechol, clonidine, diphenhydramine, and fluoxetine. Upon arrival at the ED, her examination reveals temperature of 38°C, heart rate of 120, respiratory rate of 16, blood pressure 85/56 mm Hg, pupils 5 mm equal and reactive, and dry skin. Which of the following is the most likely medication that caused the girl’s findings?