Naloxegol is recommended, within its marketing authorisation, as an option for treating opioid induced constipation in adults whose constipation has not adequately responded to laxatives.
An inadequate response is defined as opioid-induced constipation symptoms of at least moderate severity in at least 1 of the 4 stool symptom domains (that is, incomplete bowel movement, hard stools, straining or false alarms) while taking at least 1 laxative class for at least 4 days during the prior 2 weeks.
Naloxegol (Moventig, AstraZeneca) is a form of naloxol which has been pegylated (that is, attached to a molecule of polyethylene glycol, or PEG). In this form, it selectively antagonises peripheral opioid receptors to relieve constipation. It has a marketing authorisation for treating opioid-induced constipation (OIC) in adults whose constipation has had an inadequate response to laxative(s). The summary of product characteristics defines an inadequate response to laxatives as concurrent symptoms of OIC of at least moderate severity while taking at least 1 laxative class for a minimum of 4 days during the last 2 weeks.
The European public assessment report for naloxegol provides further clarification regarding the definition of an inadequate response to laxatives. It states that a person must have been taking 1 laxative class for a minimum of 4 days out of the 14 days prior to the screening visit and report moderate, severe, or very severe symptoms in at least 1 of the 4 stool symptom domains.