Which antimuscarinic agent is the drug of choice for prophylaxis of motion sickness?
- A Scopolamine ✓
- B Atropine
- C Glycopyrrolate
- D Hyoscine butylbromide
Correct answer: A. Scopolamine
Explanation
Scopolamine crosses the blood-brain barrier well and blocks muscarinic receptors in the vestibular nuclei and vestibulo-cerebellar pathway, making it the standard agent for motion sickness prophylaxis. Hyoscine butylbromide is a quaternary ammonium derivative that does not cross the blood-brain barrier, so it lacks central antiemetic activity despite being a close chemical relative. Glycopyrrolate is also quaternary and peripherally selective.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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