Webster, L., Jansen, J.P., Peppin, J., Lasko, B., Irving, G., Morlion, B., . . . Carter, E. (2008). Alvimopan, a peripherally acting mu-opioid receptor (PAM-OR) antagonist for the treatment of opioid-induced bowel dysfunction: Results from a randomized, double-blind, placebo-controlled, dose-finding study in subjects taking opioids for chronic non-cancer pain. Pain, 137, 428–440.doi: 10.1016/j.pain.2007.11.008
To assess the effectiveness and safety of alvimopan, a peripherally acting mu-opioid receptor antagonist, in patients with noncancer pain and opioid-induced bowel dysfunction.
Patients were randomized to one of four groups: oral alvimopan 0.5 mg twice daily (n = 130), oral alvimopan 1 mg daily (n = 133), oral alvimopan 1 mg twice daily (n = 130), or placebo capsules (n = 129).
Patients were instructed to discontinue laxative use. Rescue laxative medication (bisacodyl 10-30 mg) could be taken if the patient experienced discomfort with no bowel movement (BM) for four consecutive days. An interactive voice response system via touch-tone telephone was used for number of BMs, associated symptoms, rescue laxative use, opioid consumption, and pain intensity.
This was a phase IIb, randomized, double-blind, placebo-controlled, parallel-group study.
Oral alvimopan increases the frequency of SBMs and improves symptoms in adults on opioid pain regimens.
Oral alvimopan may be effective for the treatment of opioid-induced constipation in patients taking opioids for chronic pain and may improve opioid-induced bowel dysfunction symptoms. Use of alvimopan does not appear to compromise analgesia or induce opioid abstinence. Additional study is necessary to look at efficacy with an oncology population and determine long-term efficacy, as well as an optimal dosing regimen.