Domperidone is preferred over metoclopramide for diabetic gastroparesis because it lacks central antidopaminergic side effects. What property of domperidone explains this difference?
- A It is a peripherally acting D2 antagonist that does not cross the blood-brain barrier ✓
- B It acts selectively on 5-HT4 receptors in the enteric nervous system
- C It is a motilin receptor agonist with no dopamine receptor activity
- D It is acetylated in the brain to an inactive metabolite
Correct answer: A. It is a peripherally acting D2 antagonist that does not cross the blood-brain barrier
Explanation
Domperidone is a peripheral D2-receptor antagonist that does not cross the blood-brain barrier significantly, so it lacks extrapyramidal side effects and hyperprolactinemia seen with metoclopramide. Metoclopramide crosses the BBB and blocks central D2 receptors, causing EPS. Domperidone does not act via 5-HT4 or motilin receptors.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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