[Mesalazine-induced myocarditis].

A 30-year-old man presented with constipation and abdominal pain. He was suspected of having ulcerative colitis, and administration of 2400mg/day of oral mesalazine was initiated. After 10 days of treatment, he experienced fever and chest pain. Blood examination, electrocardiography, and cardiac ultrasonography revealed elevated cardiac enzymes, ST-segment elevation, and diffuse hypokinesis, respectively. Mesalazine-induced acute myocarditis was diagnosed based on a positive drug-induced lymphocyte stimulation test and the absence of other myocarditis-causing conditions. Prompt cessation of mesalazine quickly improved his heart function and test results. Although rare, clinicians should consider the possibility of cardiac adverse events caused by mesalazine.