Long-term vonoprazan administration causes gastric fundic gland-type hyperplastic polyps and chronic bleeding.

A patient experienced gastric fundic gland-type hyperplastic polyps, consisting of foveolar epithelium and parietal cells, complicated with chronic bleeding due to long-term treatment with vonoprazan. The patient had progressive anemia, probably caused by bleeding from the polyps. After switching from vonoprazan to a histamine-2 (H2) receptor antagonist, the polyps markedly shrank and the anemia improved. Vonoprazan can produce reversible hyperplastic polyps and anemia. In case of anemia in patients receiving long-term vonoprazan, it is important to consider drug cessation or change to an H2 blocker.