Methylnaltrexone

Methylnaltrexone is a peripherally acting mu-receptor antagonist. It is ineffective for opioid-induced ventilatory impairment management, but it has a role in the treatment of opioid-induced constipation. In Australia, methylnaltrexone is only approved for patients receiving palliative care when response to other laxative therapy is inadequate, see Opioid-induced constipation in palliative care.