Naloxegol for treating opioid‑induced constipation

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.

The most commonly reported adverse reactions to naloxegol are abdominal pain, diarrhoea, nausea, headache and flatulence. The majority of gastrointestinal adverse reactions are graded as mild to moderate, occur early in treatment and resolve with continued treatment. For full details of adverse reactions and contraindications, see the summary of product characteristics.

The list price for naloxegol, which has been agreed by the Department of Health, is £55.20 per 30‑tablet pack of 12.5‑mg or 25‑mg film‑coated tablets. The recommended dose is 25 mg taken orally once daily (or 12.5 mg for people with renal insufficiency). Costs may vary in different settings because of negotiated procurement discounts.