A 22-year-old man is brought to the emergency department with delirium, hyperthermia, dry skin, bilateral mydriasis, and tachycardia after consuming a herbal preparation. Which receptor is competitively antagonized by the toxin responsible for this toxidrome?

• A Dopamine D2 receptors
• B Nicotinic acetylcholine receptors
• C GABA-A receptors
• D Muscarinic acetylcholine receptors ✓

Explanation

Datura stramonium contains atropine and scopolamine, which act as competitive antagonists at muscarinic acetylcholine receptors. This blockade produces the classic anticholinergic toxidrome characterized by dry skin, mydriasis, and delirium. Nicotinic receptors mediate muscle fasciculations in organophosphate poisoning. GABA-D receptors are targeted by benzodiazepines and alcohol, while dopamine A2 receptors are blocked by typical antipsychotic agents.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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