Methylnaltrexone for Opioid-Induced Constipation in Advanced Illness

Abstract

Subcutaneous methylnaltrexone rapidly induced laxation in patients with advanced illness and opioid-induced constipation. Treatment did not appear to affect central analgesia or precipitate opioid withdrawal. (Clinical Trials.gov number, NCT00402038 [ClinicalTrials.gov].).

Subcutaneous methylnaltrexone for treatment of acute opioid‐induced constipation: Phase 2 study in rehabilitation after orthopedic surgery

“…The chosen 12-mg unit dosing corresponds to approximately 0.15 mg/kg (assuming an 80-kg patient) and was found to be both efficacious and well tolerated in the treatment of OIC in prior studies, including studies in advanced-illness patients 17,18 20 The first dose of study medication was administered on the day of randomization or on the next calendar day. Once enrolled, the patient received once-daily doses of methylnaltrexone for up to 4 or 7 days.…”

“…[14][15][16] Two randomized, doubleblind, placebo-controlled studies of methylnaltrexone in 288 patients with advanced illness and OIC showed that methylnaltrexone rapidly induced laxation without compromising analgesia. 17,18 Methylnaltrexone is currently approved for the treatment of OIC in patients with advanced illness who are receiving palliative care, when response to laxative therapy has not been sufficient. 19 Recently, the use of methylnaltrexone for the treatment of OIC in patients with chronic, nonmalignant pain was assessed in a randomized, double-blind, placebo-controlled trial of more than 400 patients.…”

Randomized placebo-controlled study of intravenous methylnaltrexone in postoperative ileus

“…Subcutaneous methylnaltrexone is approved by the US Food and Drug Administration for the treatment of opioid-induced constipation in patients with advanced illness who are receiving palliative care, when response to laxative therapy has been insufficient17. Studies have demonstrated rapid laxation compared with placebo in patients with advanced illness and opioid-induced constipation18.…”

Are we able to Manage Effectively Opioid-Induced Bowel Dysfunction?

“…New approach comprises opioid antagonists with peripherally restricted mode of action as is the case with methylnaltrexone [14] or both central and peripheral effects such as naloxone. However, naloxone is nearly completely inactivated in the liver and has negligible systemic bioavailability when administered orally in controlled-release tablets with oxycodone in a dose ratio 1:2.…”