A 55-year-old woman with rheumatoid arthritis requires long-term NSAID therapy. She is prescribed misoprostol for gastric ulcer prophylaxis. The protective mechanism of misoprostol is:

• A Prostaglandin analog that blocks histamine H2 receptors on parietal cells
• B Prostaglandin E1 analog that inhibits parietal cell H+/K+-ATPase
• C Synthetic prostaglandin that neutralizes gastric acid directly
• D Prostaglandin E1 analog that increases mucus and bicarbonate secretion and mucosal blood flow ✓

Explanation

Misoprostol is a PGE1 analog that replaces the protective prostaglandins depleted by NSAIDs. It enhances mucosal defense by increasing mucus and bicarbonate secretion, maintaining mucosal blood flow, and stimulating epithelial renewal. It does not inhibit acid secretion directly, neutralize acid, or block H2 receptors.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.