Case Presentation: 71 y/o male with a past medical history of ITP, CKD, HTN presents with a five month history of unresolved abdominal pain and diarrhea, in the setting of three ED visits and a prior admission six week ago. The patient notes profuse diarrhea throughout the day and night nausea and vomiting, and an eighteen-kilogram weight loss over five months. His home medication list consists of Olmesartan/amlodipine as well as PPI, doxycycline, and pancreatic enzymes which were added during recent hospitalization. In the ED, the patient was hypotensive, with point of care ultrasound showing a flattened IVC, chest XR was normal, and Cr 1.67 (baseline 1.30). At admission, C diff and GI pathogen panel ordered. GI was consulted and an evaluation for neuroendocrine tumor, given prior work up showing a pancreatic cyst. Glucagon, fasting gastrin, VIP, somatostatin, Chromogranin A, 5HIAA of urine, and tryptase ordered. Serum FLC was sent to evaluate for amyloid. All studies negative, except elevated chromogranin A. GI started forty-eight-hour stool collection with fecal fat quantitative, that showed secretory diarrhea. Pt had up to twenty total episodes of daily and nightly bowel movements and was trialed on multiple antidiarrheals, with octreotide being most effective. Colonoscopy was unremarkable and EGD with duodenal biopsies showed acute on chronic duodenitis. CT Enteropathy abdomen/pelvis was not impressive. When a sprue-like pattern on biopsy was recognized, the patient’s medication list was revisited. Given the exclusion of other causes of secretory diarrhea, Olmesartan -associated enteropathy was suspected. Olmesartan was discontinued and the patient was started on IV steroids with immediate improvement in symptoms. The patient was discharged on an oral steroid taper with lasting resolution of symptoms.
Discussion: Discussion: Olmesartan associated enteropathy (OAE) is a rare, but increasingly documented side effect of angiotensin receptor blockers1. OAE occurs in patients with long term use of the drug and can occur years after the medication is started. Common symptoms include abdominal pain, bloating, diarrhea, nausea, and vomiting 2,3. In severe OAE patients require hospitalization and total parenteral nutrition, can develop acute renal failure, and/or have weight loss of more than ten kilograms4. Pathogenesis is predicted to be due to an immune response to the drug metabolite in the GI tract, but still unclear. Work up of these patients involves evaluation for celiac disease, inflammatory bowel disease, and infection. Common studies collected are antibody serologies, GI pathogen panels, stool collection, endoscopy, colonoscopy, and biopsy2. During endoscopy, gastric inflammation may be observed and biopsies will show a sprue-like pattern, with variable degrees of villus blunting.3 When patients are taken off Olmesartan their symptoms quickly improve. This improvement can be augmented by the addition of steroids and other anti-inflammatory agents2.
Conclusions: In an unknown patient population, chronic olmesartan use can trigger gastrointestinal tract inflammation, resulting in severe diarrhea and weight loss. Recognizing these symptoms as a potential medication side effect and stopping Olmesartan can prevent patient morbidity and significantly decrease utilization of hospital resources.