Efficacy of methylnaltrexone for the treatment of opiod-induced constipation: a meta-analysis and systematic review

• Published in: Postgraduate medicine 2016-04, Vol.128 (3), p.282-289
• Main Authors: Mehta, Neel, O'Connell, Kelli, Giambrone, Gregory P., Baqai, Aisha, Diwan, Sudhir
• Format: Article
• Language: English
• Subjects: advanced illness; Analgesics, Opioid - adverse effects; Chronic Pain - drug therapy; chronic severe pain; Constipation - chemically induced; Constipation - drug therapy; Humans; Methylnaltrexone; Naltrexone - analogs & derivatives; Naltrexone - therapeutic use; Narcotic Antagonists - therapeutic use; opioid analgesics; opioid-induced bowel dysfunction; opioid-induced constipation; opioids; Quaternary Ammonium Compounds - therapeutic use; Receptors, Opioid, mu - antagonists & inhibitors; Treatment Outcome; μ-receptor antagonist
• ISSN: 0032-5481; 1941-9260
• DOI: 10.1080/00325481.2016.1149017

Objective: Constipation is a common adverse effect in patients requiring long-term opioid therapy for pain control. Methylnaltrexone, a quaternary peripheral mu-opioid receptor antagonist, is an effective treatment of opioid induced constipation (OIC) without affecting centrally mediated analgesia. Our objective was to conduct a review and meta-analysis to evaluate the efficacy of methylnaltrexone for treatment of OIC, as well as to provide a clinical discussion regarding newly developed alternatives and provide the current treatment algorithm utilized at our institution. Methods: We performed a systematic review and meta-analysis of randomized control trials using Cochrane Collaboration Databases and MEDLINE from 2007-present. Literature related to methylnaltrexone, opioids, opioid receptors, opioid antagonists, opioid-induced constipation were reviewed. A meta-analysis was completed with the primary outcome of rescue-free bowel movement (RFBM) within four hours of administration. All pooled analyses were based on random-effects models. Results: 1239 patients were analyzed; 599 received methylnaltrexone and 640 received placebo. With a 95% CI calculated, the true risk difference is between 0.267 and 0.385, demonstrating a statistically significant difference in RFBM between treatment and placebo groups (p