[Diarrhoea and malabsorption due to olmesartan use]

Area of Science:

• Gastroenterology
• Pharmacology

Background:

• Villous atrophy in diarrhoea has a broad differential diagnosis, commonly including coeliac disease.
• Medication-induced enteropathy is a less common but important consideration.

Observation:

• A 63-year-old man presented with secretory diarrhoea, acute renal failure, and metabolic acidosis.
• Biopsies showed total villous atrophy (Marsh stage IIIC) with intraepithelial lymphocytosis.
• Symptoms persisted despite a gluten-free diet but improved with temporary cessation of antihypertensive medications.

Findings:

• An association was identified between the patient's enteropathy and the antihypertensive medication olmesartan.
• Permanent discontinuation of olmesartan led to sustained clinical improvement.

Implications:

• Olmesartan should be considered in the differential diagnosis of patients presenting with diarrhoea and villous atrophy.
• This finding is particularly relevant given the widespread prescription of olmesartan.