Using methylnaltrexone in opioid-induced constipation

Abstract

Methylnaltrexone (Relistor) is the first peripherally-acting mu (¼)-opioid receptor antagonist to be licensed for the treatment of opioid-induced constipation in adults with advanced illness receiving palliative care, when response to regular laxative therapy has been inadequate. Methylnaltrexone is a new drug in its own classification. It is not classed as a laxative but is designed to target the underlying cause of opioid-induced constipation by reversing the peripheral effects of opioids on the gastrointestinal tract. This article explores the uniqueness of the drug and how it has been used in clinical practice at the London Bridge Hospital.