Opioids are a class of medications frequently used for the treatment of acute and
chronic pain, exerting their desired effects at central
opioid receptors. Agonism at peripherally located
opioid receptors, however, leads to
opioid-induced constipation (OIC), one of the most frequent and debilitating side effects of prolonged
opioid use. Insufficient relief of OIC with lifestyle modification and traditional
laxative treatments may lead to decreased compliance with
opioid regimens and undertreated
pain. Peripherally acting
mu-opioid receptor antagonists (PAMORAs) offer the reversal of OIC without loss of central
pain relief. Until recently, PAMORAs were restricted to subcutaneous route or to narrow patient populations.
Naloxegol is the first orally dosed PAMORA indicated for the treatment of OIC in noncancer patients. Studies have suggested its efficacy in patients failing traditional
constipation treatments; however, insufficient evidence exists to establish its role in primary prevention of OIC at this time.