FDA Approves Entereg to Help Restore Bowel Function Following Surgery

The U.S. Food and Drug Administration approved Entereg (alvimopan) May 20, 2008, to accelerate the restoration of normal bowel function in patients 18 years and up who have undergone partial large or small bowel resection surgery. Entereg will be used in hospitalized patients who can receive no more than 15 doses.

"Patients who have undergone abdominal surgery and are on pain medications often experience problems eliminating waste," said Joyce Korvick, M.D., deputy director, Division of Gastroenterology Products. "Entereg will help accelerate their recovery, improve bowel function, and get these patients back on a normal diet. As with all FDA-approved products, the agency will monitor Entereg throughout its life cycle."

FDA is approving Entereg with a Risk Evaluation and Mitigation Strategy (REMS) to ensure that the benefits of the drug outweigh the risks. The REMS will include limits on dispensing of the drug.

In approving Entereg, FDA determined that a REMS is necessary to ensure that the benefits of Entereg outweigh its risks. The REMS will include restricting Entereg to inpatient use only, requiring that hospitals be specially certified, distribution of educational materials to health care professionals, and regular assessments of the effectiveness of the REMS.

Following major abdominal surgery, some patients develop a condition known as postoperative ileus (POI). POI is a disorder that causes temporary impairment of the gastrointestinal (GI) tract's motility, or the ability of the intestines to push out waste products (not a complete blockage of the GI tract), following surgery. POI can be a by-product of a patient taking opioid pain relievers, like morphine, prescribed after surgery which can slow or inhibit normal motility. Entereg works by blocking opioid effects in the bowel.

The recommended dose for Entereg is one 12 milligram (mg) capsule given just prior to surgery and then another 12 mg dose administered twice daily for up to 7 days or not to exceed 15 doses. The product will only be available to hospitals and will come in blister packs that are marked "HOSPITAL USE ONLY." Entereg is not approved for use in pediatric populations.

The safety and efficacy of Entereg in post-operative patients were demonstrated in five studies that included 2,177 patients, of whom 1,096 received Entereg and 1,081 received placebo. Bowel recovery times ranged from 10 to 26 hours shorter for Entereg-treated patients compared to placebo-treated patients in the five studies. The most common side effects reported were low blood calcium levels, anemia and gastrointestinal problems, including constipation, dyspepsia (heartburn) and flatulence (excess bowel gas).

FDA has reviewed a 12-month study of Entereg in patients treated with opioid medications for chronic pain. In this study, there were more reports of myocardial infarctions in patients treated with a 0.5 mg dose of Entereg twice daily, compared with placebo-treated patients. This imbalance has not been observed in other studies of Entereg, including studies in patients undergoing bowel resection surgery who took 12 mg of Entereg, twice daily for up to seven days. A causal relationship with Entereg and myocardial infarction has not been established.

Consumers and health care professionals are encouraged to report adverse events to FDA's MedWatch program at 800-FDA-1088 or online at www.fda.gov/medwatch/how.htm.

Adolor Corporation, the manufacturer of Entereg, is based in Exton, PA. Adolor and GlaxoSmithKline, London, England, are collaborating on the development and marketing of Entereg.