Potassium‐Competitive Acid Blocker‐Associated Gastric Hyperplastic Polyps With Severe Bleeding: A Case Series

Gastric hyperplastic polyps can cause gastrointestinal bleeding, and their enlargement has been associated with long-term acid-suppressive therapy. Vonoprazan (VPZ), a potassium-competitive acid blocker, provides potent acid suppression and may induce hypergastrinemia, potentially contributing to the growth of hyperplastic polyps. However, clinical information regarding VPZ-associated gastric hyperplastic polyps remains limited. We report three cases of severe bleeding from gastric hyperplastic polyps in patients who were administered VPZ. Case 1 involved a 92-year-old woman who presented with melena and anemia. Endoscopy revealed an 8-cm hyperplastic polyp, and although resection was considered, it was deferred. After switching from VPZ to an H2-receptor antagonist (H2RA), her anemia gradually improved, and the polyp regressed. Case 2 involved a 61-year-old man with hematemesis due to bleeding from multiple hyperplastic polyps. Emergency endoscopic mucosal resection was performed, and markedly elevated serum gastrin levels were noted. Following the replacement of VPZ with an H2RA, the size of the remaining polyps decreased. Case 3 involved a 54-year-old man with anemia and recurrent bleeding from hyperplastic polyps, requiring multiple endoscopic treatments. After VPZ discontinuation and H2RA initiation, the unresected polyps regressed. Two patients were undergoing hemodialysis, which may have exacerbated hypergastrinemia and bleeding. In all three cases, switching from VPZ to an H2RA resulted in the regression of gastric hyperplastic polyps and improvement of anemia. In patients receiving VPZ who develop progressive anemia or bleeding from hyperplastic polyps, discontinuation of VPZ or switching to an H2RA may be effective.