Selective Postoperative Inhibition of Gastrointestinal Opioid Receptors

Abstract

BACKGROUND: Postoperative recovery of gastrointestinal function and resumption of oral intake are critical determinants of the length of hospital stay. Although opioids are effective treatments for postoperative pain, they contribute to the delayed recovery of gastrointestinal function. METHODS: We studied the effects of ADL 8-2698, an investigational opioid antagonist with limited oral absorption that does not readily cross the blood-brain barrier, on postoperative gastrointestinal function and the length of hospitalization. We randomly assigned 79 patients--including 1 whose surgery was canceled--to receive one capsule containing 1 mg or 6 mg of ADL 8-2698 or an identical-appearing placebo capsule two hours before major abdominal surgery and then twice daily until the first bowel movement or until discharge from the hospital. Data were analyzed for 26 patients in each of the three groups; all received opioids for postoperative pain relief. Observers who were unaware of the group assignments evaluated the outcomes. RESULTS: Fifteen patients underwent partial colectomy and 63 underwent total abdominal hysterectomy. Patients given 6 mg of ADL 8-2698 had significantly faster recovery of gastrointestinal function than those given placebo. The median time to the first passage of flatus decreased from 70 to 49 hours (P=0.03), the median time to the first bowel movement decreased from 111 to 70 hours (P=0.01), and the median time until patients were ready for discharge decreased from 91 to 68 hours (P=0.03). Effects in the group that received 1 mg of ADL 8-2698 were less pronounced. CONCLUSIONS: Selective inhibition of gastrointestinal opioid receptors by an antagonist with limited oral absorption that does not readily cross the blood-brain barrier speeds recovery of bowel function and shortens the duration of hospitalization.