Naloxegol is a PEGylated derivative of the opioid antagonist naloxone. PEGylation (that is, attachment to a molecule of polyethylene glycol, or PEG) prevents naloxegol from penetrating the CNS; thus it acts peripherally to lessen the constipating effects of opioids without antagonising their central analgesic effects.
NICE technology appraisal 345 recommends naloxegol as an option for treating opioid-induced constipation in adults who have not responded adequately to laxatives.
An inadequate response is defined as opioid-induced constipation symptoms of at least moderate severity in at least one of the four stool symptom domains (that is, incomplete bowel movement, hard stools, straining or false alarms) while taking at least one class of laxative for at least four days during the preceding two weeks.
The recommended dose of Moventig is 25mg once daily (or 12.5mg daily in people with renal impairment). It is supplied as 12.5mg and 25mg tablets.