Mesalazine-induced myopericarditis: a case report.

Background: Mesalazine is a well-established 1st line treatment for inflammatory bowel disease (IBD). Cardiotoxicity following 5-aminosalicyclic-acid therapy remains a rare yet serious complication and can often be challenging to distinguish from myocarditis presenting as an extra-intestinal manifestation of IBD.

Case Summary: We present a case of a 22-year-old man with a background of ulcerative colitis commenced on a mesalazine preparation for disease progression. He presented to our hospital 12 days following drug initiation with acute chest pain, peak troponin-T of 242 ng/L, dynamic electrocardiogram changes, and severe left ventricular systolic dysfunction on transthoracic echocardiogram. The clinical diagnosis of myopericarditis was suspected and mesalazine was stopped shortly after. Outpatient cardiac magnetic resonance performed 2 weeks following mesalazine cessation demonstrated a recovery of cardiac function with associated symptom and biochemical resolution.

Discussion: Clinicians should be aware of this potentially fatal adverse effect of a commonly prescribed medication. Symptoms of myocarditis often occur within the early stages of mesalazine initiation, which aids the clinical diagnosis. The mainstay of treatment is to simply discontinue the drug with rapid resolution of symptoms seen without any permanent or long-term cardiac dysfunction. Close liaison with the gastroenterology team is key, as 2nd line IBD therapies are often required for the ongoing management of the patient's colitis.