A 60-year-old man presents with anhidrosis, urinary retention, dry mouth, and mydriasis after eating wild berries. This toxidrome is best treated with:

• A Atropine
• B Pralidoxime
• C Neostigmine
• D Physostigmine ✓

Explanation

The presentation is classic anticholinergic toxidrome (dry, hot, flushed, blind, mad, tachycardic) from belladonna alkaloids (scopolamine/atropine) in Atropa belladonna berries. Physostigmine is the antidote because it is a tertiary amine that crosses the blood-brain barrier, inhibiting AChE and increasing central and peripheral acetylcholine to overcome muscarinic blockade. Neostigmine is quaternary and does not cross the BBB, so it cannot reverse CNS effects. Pralidoxime is used for organophosphate poisoning, not belladonna alkaloids.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.