A 55-year-old man with osteoarthritis takes celecoxib, a selective COX-2 inhibitor, for pain. Compared to non-selective NSAIDs, why does celecoxib carry lower risk of peptic ulcer disease?
- A It directly protects the gastric mucosa by stimulating mucus secretion
- B It does not inhibit COX-1, which maintains gastric mucosal protection via prostaglandins ✓
- C It inhibits COX-2 only in inflamed tissues, sparing constitutive COX-2 in the stomach
- D It is a reversible COX inhibitor, unlike irreversible aspirin
Correct answer: B. It does not inhibit COX-1, which maintains gastric mucosal protection via prostaglandins
Explanation
COX-1 is constitutively expressed in gastric mucosa and produces cytoprotective prostaglandins (PGE2, PGI2). Non-selective NSAIDs inhibit both COX-1 and COX-2, causing ulcer risk. Selective COX-2 inhibitors spare COX-1, preserving gastric protection. Celecoxib does not stimulate mucus secretion. COX-2 is inducible, not constitutive in stomach.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.