Definition

A pegylated form of naloxone, a peripherally-acting mu-opioid receptor antagonist, that can be used to reduce opioid-induced symptoms. Upon administration, naloxegol binds to and blocks mu-opioid receptors in the peripheral nervous system. This prevents peripheral opioid receptor activation and abrogates opioid-induced side effects, such as opioid-induced constipation (OIC). Pegylation of naloxone reduces permeability across the blood-brain barrier (BBB) and prevents this agent from interfering with the analgesic activity of opioid receptor agonists.