Which medication prevents the release of stomach acid?

• A. Antacids
• B. Prokinetic
• C. H2-receptor blockers
• D. Antiemetic

Answer: (C)

Acid production by stomach parietal cells is driven in part by histamine binding to its H2 receptors, which stimulates acid secretion. Blocking those receptors stops that signal, so the parietal cells release less acid. This is exactly what H2-receptor blockers do—they prevent acid secretion by inhibiting histamine’s action on the parietal cells, lowering both basal and meal-stimulated acid output.

Antacids work by neutralizing acid that's already in the stomach, not by preventing its release. Prokinetics change GI motility and can influence symptoms, but they don’t primarily stop acid production. Antiemetics target nausea and vomiting, not acid secretion. So the best choice for preventing acid release is the H2-receptor blocker.