The antiemetic aprepitant exerts its effect by antagonism of which receptor?
- A 5-HT3 receptor in the chemoreceptor trigger zone
- B Histamine H1 receptor in the vestibular apparatus
- C Neurokinin-1 receptor in the vomiting centre ✓
- D Dopamine D2 receptor in the area postrema
Correct answer: C. Neurokinin-1 receptor in the vomiting centre
Explanation
Aprepitant and fosaprepitant are substance P neurokinin-1 receptor antagonists acting centrally at the nucleus tractus solitarius and vomiting centre. They are reserved as rescue agents or add-ons when 5-HT3 antagonist based prophylaxis fails, and have a duration of action up to 24 hours. The other receptors are the targets of ondansetron, cyclizine and droperidol respectively.
Reference: Miller's Anesthesia, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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