Methimazole-induced acute pancreatitis: a case report

A 76-year-old Japanese woman was diagnosed with Graves’ disease and was administered methimazole (MMI) 10 mg and potassium iodide 50 mg. After 19 days of the drug regime, she developed high-grade fever and nausea and was admitted to our hospital. Blood test results showed elevated pancreatic enzymes and C-reactive protein levels. Abdominal computed tomography showed swollen pancreas, and she was diagnosed with acute pancreatitis. These abnormalities improved after discontinuation of MMI. Five similar cases have been reported, but this is the first case report without abdominal pain. When acute pancreatitis is observed after the initiation of MMI, drug-induced pancreatitis should be considered as the possible etiology.