A medical student consumes datura seeds as part of a ritual and presents with agitation, dry flushed skin, mydriasis, tachycardia, and visual hallucinations. Which drug is most appropriate to reverse the central anticholinergic syndrome?

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

Explanation

Physostigmine is a tertiary amine carbamate that crosses the blood brain barrier, so it can reverse both peripheral and central features of anticholinergic toxicity such as delirium and hallucinations. Neostigmine is a quaternary ammonium compound and cannot enter the CNS, so it would only produce peripheral cholinergic effects while leaving the encephalopathy untouched. Pilocarpine acts mainly on muscarinic receptors peripherally and does not reliably reverse CNS toxicity.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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