Taguchi, A., Sharma, N., Saleem, R.M., Sessler, D.I., Carpenter, R.L., Seyedsadr, M., & Kurz, A. (2001). Selective postoperative inhibition of gastrointestinal opioid receptors. New England Journal of Medicine, 345, 935–940.doi: 10.1056/NEJMoa010564
To evaluate the effects of alvimopan on postoperative gastrointestinal (GI) function and length of hospitalization.
Alvimopan is an investigational opioid antagonist with limited oral absorption that does not readily cross the blood-brain barrier and, therefore, acts on the peripheral opioid receptors in the GI tract without affecting analgesia in patients taking opioids. Doses used in the study were 1 mg and 6 mg by mouth. On the day of surgery, patients were randomly assigned in equal proportions to one of three arms using computer-generated randomization stratified according to type of surgery. The three arms were 1 mg of alvimopan, 6 mg of alvimopan, or an identical appearing placebo. Patients took the drug or placebo two hours before surgery and then twice daily postoperatively until the first bowel movement, until discharge from the hospital, or for a maximum of seven days. Patients were seen twice daily by the research team, from 6 am to 8 am and then from 4 pm to 6 pm. At each visit, patients were asked about time of first passage of flatus and first bowel movement. Oral intake was measured until patients could tolerate regular meals. Subjects were considered ready for discharge if they had adequate oral intake to discontinue IV fluids, GI function had returned (defined as passage of flatus), they were afebrile, and they were free of major complications.
This was a randomized, placebo-controlled study.
The 6-mg dose of alvimopan improved all major outcomes, with or without correction for the type of surgery. Analgesic efficacy of opioids was not affected by the study drug, and no adverse events occurred.