2055 A Case Report of Rectal Mesalamine-Induced Myopericarditis

Abstract

INTRODUCTION: Inflammation of the pericardium, myocardium or both is a rare but known side effect of 5-aminosalicyclic acid (5-ASA) containing medications. While most reports in the literature of this side effect have occurred with oral mesalamine, our patient developed myopericarditis approximately 3 weeks after initiation of rectal mesalamine suppositories. CASE DESCRIPTION/METHODS: A 37-year-old man with a history of hypertension, GERD, irritable bowel syndrome and proctitis on rectal mesalamine suppositories presented to the emergency department with acute onset pleuritic chest pain and was found to have elevated troponin and non-specific ST segment changes on electrocardiogram. Initially he was evaluated for possible acute coronary syndrome; however given positional and respirophasic nature of the pain, his symptoms were felt to be more consistent with myopericarditis. Transthoracic echocardiogram showed a small pericardial effusion without tamponade and no significant wall motion abnormities. Cardiac MRI was consistent with myocarditis. Evaluation for infectious or autoimmune etiologies of myopericarditis was unrevealing, including negative ANA and Lyme antibody. He had been started on rectal mesalamine suppositories 3 weeks prior to presentation after colonoscopy showed proctitis concerning for possible ulcerative colitis. Later review of his colonoscopy findings and chronic gastrointestinal symptoms was more consistent with irritable bowel syndrome than ulcerative colitis. The rectal mesalamine was felt to be the most likely etiology of his myopericarditis and was stopped during the hospitalization. He was treated with a course of naproxen and colchicine with rapid resolution of chest pain. DISCUSSION: Myocarditis and pericarditis are well-described and potentially lethal side effects of drugs containing 5-ASA, although the mechanism for cardiac toxicity is not clear. Symptoms usually manifest within 28 days of drug initiation and may resolve with drug cessation alone. While the absorption of oral mesalamine is estimated to be around 20-45%, rectal mesalamine absorption is variable and likely depends of a variety of factors including retention time and degree of underlying rectal disease. Our case suggests that rectal absorption alone may be sufficient to cause cardiac toxicity and that rectal mesalamine may not be safe in patients who have previously had cardiac or other toxicity on oral 5-aminosalicyclic acid containing drugs.