Naloxegol: A Review of Clinical Trials and Applications to Practice

Opioid-induced constipation is a known side effect of long-term opioid therapy and may contribute to increased healthcare utilization. Common laxatives such as polyethylene glycol and bisacodyl are often selected as first-line agents. However, refractory constipation may persist despite the addition of a second agent. In such situations, alternate agents may be considered. The peripherally acting mu-opioid receptor antagonist naloxegol was approved in 2014 for management of opioid-induced constipation in adult patients with chronic noncancer pain. This agent is similar to the mu-opioid antagonist naloxone but selectively blocks opioid receptors in the periphery, thereby preventing constipation while avoiding any worsening of pain scores. Given that the medication undergoes hepatic metabolism, it is important to monitor liver function prior to initiation and assess for other medications, which may increase or decrease the levels of naloxegol, to determine whether adjustment in therapy may be required.