S3478 Recognition of Olmesartan Enteropathy as a Cause of Chronic Persistent Diarrhea

INTRODUCTION: Olmesartan was first associated with a sprue-like enteropathy back in 2012. The mechanism of this enteropathy is still poorly understood with theories ranging from cell mediated immune damage to modulation of transforming growth factor beta. Complications can include weight loss and electrolyte derangements that can potentially result in hospitalization. Olmesartan enteropathy may still be an under-recognized cause of chronic, persistent diarrhea. Here, we briefly present 2 cases of olmesartan-associated enteropathy. CASE DESCRIPTION/METHODS: A 73 year old male was referred for “refractory celiac disease” with a history notable for 6 to 10 bowel movements per day. His clinical course was complicated by hypokalemia, hypomagnesemia, and weight loss. Celiac serologies were negative. He had undergone thorough workup including upper and lower endoscopy. Endoscopic examination of the duodenum showed atrophic mucosa and scalloping of the rings of Kerckring. Biopsy was significant for villous atrophy and lymphocytic infiltrate. He had been taking olmesartan for hypertension and after discontinuation, symptoms showed signs of improvement by weeks 2-3 and completely resolved by week 5. A 68 year old male presented to the clinic with 2 to 3 months of diarrhea. He had been taking olmesartan for 4 years for hypertension. He underwent evaluation for carbohydrate metabolism and SIBO, which were negative. Stool lactoferrin was modestly elevated at 43.5 and there were no signs of exocrine pancreatic insufficiency. Celiac serologies were again negative. Colonoscopy with biopsies were unremarkable. An EGD was finally performed where visible mucosal atrophy of the duodenum was observed. Biopsies revealed lymphocytic infiltration. After discontinuation of olmesartan, he rapidly improved and achieved complete remission. DISCUSSION: Our cases appear to clearly depict patients that develop enteropathy in association with long-standing olmesartan treatment. During a brief literature review, we found multiple other cases similar to the cases we described above2-5. Patients underwent a basic workup that was ultimately unremarkable with the exception of their duodenal biopsies. Once olmesartan was eventually discontinued, symptoms rapidly improved. In the workup of chronic, persistent diarrhea, it is prudent to maintain a broad differential diagnosis, but to also have an increased sensitivity and awareness of the effects that long-standing olmesartan may have.