An unusual cause of diarrhoea: case report and literature review of olmesartan-associated enteropathy

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

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.

Systematic review: Clinical phenotypes, histopathological features and prognosis of enteropathy due to angiotensin II receptor blockers

BACKGROUND

Although enteropathy due to angiotensin II receptor blockers (ARBs) has been known for over 10 years, clinicians' awareness of this condition is still low.

AIMS

To systematically review the literature about clinical phenotypes, distribution of mucosal changes throughout the gastrointestinal tract and prognosis of enteropathy due to ARBs.

METHODS

According to PRISMA guidelines, we searched PubMed and Embase for relevant articles up to November 6, 2023. We included full-text papers, letters, case reports and case series describing enteropathy due to ARBs. Patients were classified into subgroups based on endoscopic and histological findings of different regions of the gastrointestinal tract. The protocol was registered with Open Science Framework (https://doi.org/10.17605/OSF.IO/TK67C).

RESULTS

We included 94 articles reporting 183 cases (101 female, mean age at diagnosis 69 ± 10 years). The clinical picture at diagnosis was characterised by severe diarrhoea (97%) and weight loss (84%, median -13 kg), leading to hospital admission in 167 (95%) patients. Olmesartan (90%) was most frequently implicated. Villous atrophy (VA) was reported in 164/183 (89%) patients. One hundred and nine had only VA, 12 had pan-gastrointestinal involvement, 23 had VA and gastric involvement and 19 had VA and colon involvement (predominantly microscopic colitis). Outcomes were reported for 178/183 (97%) patients, who all recovered clinically on ARBs withdrawal. Histological recovery occurred in all 96 patients with VA at baseline who underwent follow-up duodenal biopsy.

CONCLUSIONS

Enteropathy due to ARBs is characterised by severe malabsorption often requiring hospital admission and can involve the entire gastrointestinal tract. Clinician awareness can lead to prompt diagnosis and excellent prognosis.