Which medication is not an acid-suppressing agent?

• A. Omeprazole
• B. Ranitidine
• C. Sucralfate
• D. Esomeprazole

Answer: (C)

The main concept is distinguishing drugs that reduce stomach acid production from those that protect the mucosa without lowering acid output. Two drugs, omeprazole and esomeprazole, are proton pump inhibitors that irreversibly inhibit the proton pump in parietal cells, dramatically reducing gastric acid secretion. Ranitidine is an H2 receptor blocker that decreases acid production by blocking histamine signaling on parietal cells. Sucralfate, however, does not lower acid production. It acts as a mucosal protectant, forming a viscous barrier that coats ulcers and erosions to shield them from acid and allow healing. It doesn’t suppress acid secretion, which is why it’s not considered an acid-suppressing agent.