Camera pill reveals damage from anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) may damage more of the intestine than previously thought, according to images taken by a swallowable, capsule-size camera pill used in a Baylor College of Medicine study.

According to the study, announced today at the Digestive Disease Week 2003 conference in Orlando, capsule endoscopy detected NSAIDs-related injury in the small bowel, an area of the gastrointestinal tract unreachable by other diagnostic tools such as endoscopes. The tool detected small bowel erosions in 62 percent of NSAID users compared to 5 percent of non-NSAID users.

“More than 100 million prescriptions for NSAIDS are written annually in the United States,” said Dr. David Graham, lead author of the study and a professor of medicine and molecular virology at Baylor in Houston and chief of the gastroenterology section of Houston VA Medical Center. “The study shows that the patients who take NSAIDs regularly have an increased risk of small intestinal mucosal ulceration and bleeding.”

NSAIDs are medications which reduce pain and inflammation over time. The drugs work by affecting chemicals in the body which cause inflammation, the prostaglandins. The same group of chemicals are also in the stomach, leading NSAIDs to cause indigestion, and possibly duodenal or stomach ulceration.

The capsule endoscope, developed by Given Imaging, allows medical professionals to view the entire small intestine. The system uses a disposable miniature video camera contained in a capsule, which the patient swallows. The capsule passes through the digestive tract, transmitting color images, without interfering with the patient’s normal activities. Capsule endoscopy diagnoses a range of diseases of the small intestine including Crohn’s Disease, Celiac disease, benign and malignant tumors of the small intestine, vascular disorders, medication related small bowel injury and pediatric small bowel disorders.

The study enrolled 40 patients, with a mean age of 49.5, who had arthritis including osteoarthritis, rheumatoid arthritis and gout. Twenty patients took NSAIDS daily for three months. Twenty patients took acetaminophen alone or nothing at all. All patients fasted overnight and underwent capsule endoscopy. The pylorus, the sphincter muscle that controls the lower opening of the stomach where it empties into the upper part of the small intestine, was marked on each video. Two investigators who were not told which therapy the participants received, reviewed each video beginning after the pylorus, where the small intestine starts.

Severe injury to the small bowel was seen in 23 percent of NSAID users compared to no severe injury in the controls. Severe damage was associated with high doses of indomethacin, naproxen, oxyprozocin and ibuprofen.

“This is a significant finding and suggests the need for periodic diagnostic monitoring with capsule endoscopy of patients who take NSAIDs regularly,” Graham said.