Mesalamine-Induced Myopericarditis

Mesalamine is a frequent initial therapy for inflammatory bowel diseases and is typically well tolerated. Common side effects include headaches, nausea, watery diarrhea, and abdominal pain, while pancreatitis, rash, and exacerbation of underlying disease are less common. Reports of cardiac side effects are even more uncommon. Herein we describe mesalamine induced myopericarditis in a patient recently treated with mesalamine for ulcerative colitis (UC). A 23 year old male, recently diagnosed with UC, presented to the ER with chest pain and cough of four day's duration. Patient began mesalamine tablets (1.6 g three/day) four days prior and mesalamine enemas two weeks earlier. Patient reported pleuritic-like chest pain but no viral symptoms, diarrhea, hematochezia, or abdominal pain. Vitals revealed BP 138/79, HR 114 bpm, RR 14 resp/min, T 102.6 °F, SpO2 99% on room air. Exam was unremarkable. Labs showed WBC 14.17 k/uL, hemoglobin 13.2 g/dL, CRP 43 mg/L, ESR 104 mm/h, and high sensitivity troponin was found to be 132. EKG revealed sinus tachycardia and diffuse, non-specific ST-T abnormalities. Chest x-ray was unremarkable and CT-PE was negative for pulmonary embolism but revealed trace pericardial fluid. TEE confirmed a trivial pericardial effusion without signs of cardiac tamponade, no wall motion abnormalities, and a preserved EF of 50-55%. Mesalamine was discontinued upon diagnosis of myopericarditis. The patient defervesced and chest pain resolved within 24 hours of discontinuing mesalamine. Repeat labs showed improvement in high sensitivity troponin and WBC counts, and blood cultures remained negative. Patient was discharged home with follow-up for an alternative steroid sparing agent for long term UC therapy. Myopericarditis describes acute inflammation of the pericardial sac and myocardium, and can be rapidly fatal if not quickly identified and managed. Mesalamine induced myopericarditis is rare and the mechanism underlying its effects on pericardial/myocardial inflammation is not well understood. It is important to distinguish between extraintestinal manifestations of UC as an etiology for myopericarditis versus drug induced side effects of mesalamine. Due to the swift onset and resolution of cardiac symptoms after initiating and discontinuing oral therapy, respectively, we hypothesize that this case represents mesalamine induced myopericarditis. Clinicians should be aware of the risk of myopericarditis in patients on mesalamine therapy.