Olmesartan can cause chronic diarrhea

The US FDA has approved a label change for the AR blocker (ARB) olmesartan to state that the drug can cause an intestinal problem known as sprue-like enteropathy.  The symptoms include severe and chronic diarrhea that results in significant weight loss. Olmesartan is the only ARB known to cause this adverse event. The agency is continuing to monitor the safety of all olmesartan-containing products.

The label change is based on an evaluation of adverse events received by the FDA's Adverse Event Reporting System (FAERS), a published literature case series, and other data. In the FAERS, the agency identified 23 patients who presented with late-onset diarrhea and significant weight loss. All patients improved clinically when olmesartan was stopped. When 10 patients were rechallenged with the drug, the symptoms appeared again.

Patients should be told to contact doctors if they develop severe, chronic diarrhea with substantial weight loss while taking an olmesartan-containing product, even if it takes months to years for symptoms to develop.