Naloxegol, designed for the treatment of opioid-induced constipation (OIC), has shown efficacy in two phase III clinical trials, published in
The New England Journal of Medicine
In the trials, which included 1,352 outpatients with non-cancer pain and opioid-induced constipation, naloxegol 25mg/day taken orally achieved a better 12-week response rate than placebo (response was defined as three or more spontaneous bowel movements per week).
OIC is a common side effect of drugs used to treat osteoarthritis and chronic back pain. Reported pain and level of opioid dose were similar between users of naloxegol and placebo. The most commonly reported adverse events with naloxegol were abdominal pain, diarrhoea, nausea and flatulence.
Naloxegol is marketed by AstraZeneca and is currently being appraised by the National Institute for Health and Care Excellence. It is a pegylated derivative of the Î¼-opioid receptor antagonist naloxone.