SESSION TITLE: Occupational and Environmental Lung Diseases SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Hypersensitivity pneumonitis has many causes and can be due to medication side effects. Here we present a patient with symptoms similar to interstitial fibrosis after recently starting Limbrel. CASE PRESENTATION: Our patient is a 69 year old woman with a history of heart failure who presented with worsening shortness of breath for the last six weeks. She checked her oxygen saturation at home and reported it was 80% with any exertion. She had no orthopnea and believed she was at her “dry weight”. On exam she was tachycardic and her oxygen saturation was 83% with mild exertion. She did not have peripheral edema or jugular venous distention. On lung exam there were bilateral fine inspiratory crackles in the lower and mid-lung fields. Chest CT revealed patchy peripheral opacities with mosaic attenuation as well as diffuse groundglass opacities with septal thickening. On evaluation of her medications, she recently started taking Limbrel 7 weeks ago for osteoarthritis. She was advised to discontinue this medication, and on follow-up her symptoms had resolved. DISCUSSION: Limbrel is a flavocoxid that inhibits the cyclooxygenase (COX) and lipoxygenase (5-LOX) pathways to exert an anti-inflammatory effect with minimal gastric, cardiovascular, and renal side effects. Approved in 2004, Limbrel is prescribed for the treatment of osteoarthritis. Its ingredients are Generally Recognized As Safe (GRAS), however adverse events are still reported, one of which is hypersensitivity pneumonitis. Limbrel’s post-marketing surveillance compiled side effects reported from 2004 through March 2012. With 324,929 prescriptions filled within this time frame, there were 269 adverse events reported, an incidence of 0.08%. Among these, the most commonly reported adverse event was GI-related (22%). 9% of the reported adverse events involved the respiratory system. Hypersensitivity pneumonitis was reported in 17 patients, giving it an overall incidence rate of 0.00523%, or around 5 out of 1,000 people. Other respiratory adverse events included dyspnea, rapid breathing, asthma, and respiratory failure. Hypersensitivity pneumonitis represents a complex syndrome rather than a single disease pattern. It is exacerbated by an extrinsic allergen that causes interstitial noncaseating granuloma formation, leading to a presentation similar to interstitial pulmonary fibrosis. In cases of HSP due to Limbrel, most show complete resolution of symptoms within two months after cessation of the drug. CONCLUSIONS: Medication side effects are a rare but important cause of interstitial lung disease that should be considered in patients who present with new onset lung disease. Reference #1: Panduranga, V., Atneinza, J., Kumar, A., & Metersky, M. (2013). Hypersensitivity pneumonitis due to flavocoxid: are corticosteroids necessary? Connecticut Medicine,77(2), 87-90. Reference #2: LIMBREL Post-Marketing Surveillance. (2012, March). Retrieved March 1, 2017, from http://www.limbrel.com/downloads/post_mkt_surv.pdf DISCLOSURE: The following authors have nothing to disclose: Lindsey Orr, Gregory Grandio, Raymond Foley No Product/Research Disclosure Information