Dear Dr. K: My gastroenterologist said that my blood pressure pill, Benicar, caused me to develop sprue. Can this be true?
To answer your question in a broad sense: “Yes;” but in a strict sense, “No.”
To better understand this yes/no scenario a few definitions would be helpful.
Sprue (also known as celiac disease) is a form of GI upset with diarrhea caused by an immune reaction to gluten. The immune reaction leads to inflammation in the intestinal wall, with resultant atrophy of the villi.
The villi are critical for properly digesting food (due to enzymes found on the villi), and for properly absorbing food (due to increasing absorptive surface area).
Benicar (Olmesartan) is one of a family of anti-hypertensives known as angiotensin receptor blockers. It has been implicated in a number of cases of chronic diarrhea, with biopsies that show villous atrophy.
However, unlike in sprue, there is no inflammation and also unlike in sprue, the illness does not improve with avoiding gluten. It does however, improve with going off the Benicar which allows the villi to regrow.
The Mayo Clinic has had a keen interest in this issue, and has even found some patients on Benicar with mild villous atrophy, but no symptoms.
What is reassuring about this research is that treatable conditions are being discovered for a large group of individuals previously labeled with “IBS” (Irritable bowel syndrome). The term syndrome means no known cause, but does not imply a cause can’t be found.
The American Journal of Medicine had an intriguing article about people with difficult-to-regulate thyroid disease.
Researchers at the University of Vermont studied patients with hypothyroidism (low-functioning thyroid) who were on thyroid replacement therapy. In many people it is easy to dial in the proper thyroid hormone regimen, but in some this can be very difficult.
When the Vermont researchers looked at this latter group they discovered a large number had previously undiagnosed celiac disease.
Since celiac disease alters absorption of nutrients it can also lead to poor absorption of medications.
Once the celiac disease was treated, the patients’ thyroid condition came under smooth control.
A recent article in the Journal of Pediatric Medicine has this interesting title: “The Complexity of Celiac Disease”.
The reason for the title surfaced when the researchers were testing the validity of the standard approach to diagnosing celiac disease. The current gold standard for diagnosis consists of having a positive blood test and having an intestinal biopsy that shows villous atrophy (shortening of the absorptive “cilia” in the gut).
This study was conducted in Finland where this disease is quite common. In the study group of patients who had a positive blood test but a normal biopsy, half went on a gluten-free diet, and half continued to eat gluten.
After a year the gluten avoiders not only felt better, but their blood tests had become negative. The group that ate gluten continued to have symptoms and most of them developed a positive result on a repeat biopsy.
Their editorial conclusion was that a positive blood test warrants at least a trial of gluten-free diet.