Olmesartan-induced gastritis with no lower gastrointestinal symptoms: A case report

A 74-year-old man with decreased appetite, weight, and heartburn was referred to our hospital. His medications included olmesartan. Esophagogastroduodenoscopy (EGD) revealed antral-dominant erosive gastritis and nodular mucosa. A gastric biopsy revealed inflammatory cell infiltration. The serum anti-Helicobacter pylori immunoglobulin G antibody test result was negative. Famotidine was ineffective in relieving his symptoms, and esomeprazole failed to prevent overt gastric bleeding, which required endoscopic hemostasis. The working diagnosis was drug-induced gastritis, particularly olmesartan-induced gastritis. His appetite loss started to improve within a week of olmesartan withdrawal. The erosions healed on EGD 2 months later. Over the next 10 months, he remained in his usual state until olmesartan was inadvertently administered. Subsequent EGD revealed a mild gastritis relapse. We diagnosed olmesartan-induced gastritis and discontinued olmesartan treatment. Mucosal healing was confirmed by EGD 1 year later. Olmesartan is known to cause angiotensin II receptor blocker-induced enteropathy. Although angiotensin II receptor blocker-induced enteropathy affects the stomach, angiotensin II receptor blocker-induced gastritis without lower gastrointestinal symptoms is rare. The characteristic endoscopic appearance may provide a clue to the correct diagnosis.