D

Misoprostol is a synthetic PGE₁ analogue that replaces the gastric prostaglandins suppressed by NSAIDs, thereby stimulating mucus/bicarbonate secretion and maintaining mucosal blood flow; multiple trials show it prevents NSAID-induced gastric ulcers whereas H₂ blockers or other agents do not [Graham, 1988, PMID 2904006; Dajani, 1995, PMID 7697902].