Chronic diarrhoea, weight loss and a positive anti-tissue transglutaminase antibody: a case report of olmesartan-induced enteropathy

In conjunction with BMJ Case Reports, DTB will feature occasional drug-related cases that are likely to be of interest to readers. These will include cases that involve recently marketed drugs for which there is limited knowledge of adverse effects and cases that highlight unusual reactions to drugs that have been marketed for several years. Olmesartan is an angiotensin II receptor blocker licensed for the treatment of hypertension. It can cause a sprue-like enteropathy (SLE), characterised by chronic diarrhoea, weight loss and villous atrophy. Transiently raised anti-tissue transglutaminase (ATTG) antibody has also been rarely reported in the literature. We describe the case of a woman in her mid-50s, who presented with a history of intermittent loose stools over 1 year, associated with significant weight loss. She had two marginally raised serum ATTG antibody tests during her work-up. After extensive investigations, she was diagnosed with olmesartan-induced enteropathy. On subsequent follow-up, her symptoms had resolved with cessation of her olmesartan therapy. This case adds to existing literature, highlighting the importance of considering olmesartan as a possible differential diagnosis for SLE. It also reports the presence of a raised ATTG antibody which is infrequently reported in this context. Olmesartan is an angiotensin II receptor blocker (ARB), first licensed for hypertension in 2002. The association between olmesartan and enteropathy was first described by Rubio-Tapia et al , with the Food and Drug Administration subsequently issuing a safety alert in 2013.1 Several large retrospective cohort studies found diagnoses of malabsorption following olmesartan therapy ranging between 0.02 and 12.49 per 100 000.2–6 While open to significant selection and information biases, we can infer from these studies that the incidence is likely to be low. There are case reports of enteropathy associated with other ARBs, but systematic reviews have shown olmesartan to cause 90–94% of ARB-associated …