Patients taking the popular high blood pressure drug Benicar (olmesartan) are at an increased risk of developing symptoms similar to an inflammatory bowel disease.

The U.S. Food and Drug Administration in July 2013 ordered Benicar maker Daiichi Sankyo to add a warning label about the celiac disease symptoms, which were characterized as “life-threatening” in a study that found more than half of the patients stricken with it required hospitalization for extreme weight loss allegedly caused by the side effects of Benicar and diarrhea.

Symptoms of sprue-like enteropathy closely mirror the inflammatory bowel disease Celiac disease, which is an intolerance to gluten. Common symptoms include severe and/or chronic diarrhea, substantial weight loss and an electrolyte imbalance.

The FDA warning came a year after the Mayo Clinic published the results of a Benicar study in which it concluded that Benicar was linked to sprue-like enteropathy.

Twenty-three people reported suffering from diarrhea and significant weight loss, and in some cases, intestinal villous atrophy on biopsy, were reported. Intestinal villous atrophy is when there is decaying in a part of the intestinal tract, making it difficult for the body to absorb nutrients, resulting in chronic dehydration, malnutrition and a weakened immune system.

Shortly afterward, researchers from the American College of Gastroenterology reported 40 additional cases of Benicar related to sprue-like enteropathy.

A study published in October in Journal of Clinical Pathology found that up to 50 percent of Benicar patients suffered sprue-like enteropathy compared with about 20 percent of patients who used other blood-pressure lowering medications.

According to the Centers for Disease Control, 67 million American adults – one in every three adults – suffer from high blood pressure, also known as hypertension. Children can also develop the disease.

The National Heart, Lung and Blood Institute defines high blood pressure as “the force of blood pushing against the walls of the arteries as the heart pumps blood. If this pressure rises and stays high over time, it can damage the body in many ways.”

High blood pressure greatly increases the risk for heart disease and stroke, the first and third leading causes of death in the United States, according to the Centers for Disease Control.

“In 2010, high blood pressure was projected to cost the United States $93.5 billion in health care services, medications, and missed days of work,” the CDC reports.

Doctors write more than 11 million prescriptions annually for Benicar, the most widely prescribed blood pressure medication in the country. The FDA approved it for commercial sale in the United States in April 2002.

The drug manufacturer is also named as the defendant in a number of Benicar lawsuits around the country, many filed by people first diagnosed with Celiac disease before figuring out Benicar was the problem. Plaintiffs are asking for compensation for medical bills, pain and suffering, and sometimes permanent injuries to their intestines.

The Benicar lawsuits accuse Tokyo-based Daiichi Sankyo of failing to adequately research the drug’s potential side effects and failing to provide sufficient warnings to patients and healthcare providers.

They claim that had the patients known of the risk of developing chronic diarrhea and other symptoms of sprue-like enteropathy, they could have opted not to take the drug and suffer unnecessary pain and suffering as well as permanent intestinal damage.