Opioid-induced constipation (OIC) is one of the most troublesome and the most common effects of
opioid use leading to deterioration in quality of life of the patients and also has potentially deleterious repercussions on adherence and compliance to
opioid therapy. With the current guidelines advocating liberal use of
opioids by physicians even for non-
cancer chronic pain, the situation is further complicated as these individuals are not undergoing
palliative care and hence there cannot be any justification to subject these patients to the severe
constipation brought on by
opioid therapy which is no less debilitating than the
chronic pain. The aim in these patients is to prevent the
opioid-induced constipation but at the same time allow the
analgesic activity of
opioids. Many drugs have been used with limited success but the most specific among them were the peripherally acting
mu opioid receptor antagonists (PAMORA).
Methylnaltrexone and
alvimopan were the early drugs in this group but were not approved for oral use in OIC. However
naloxegol, the latest PAMORA has been very recently approved as the first oral
drug for OIC. This article gives an overview of OIC, its current management and more specifically the development and approval of
naloxegol, including pharmacokinetics, details of various clinical trials, adverse effects and its current status for the management of OIC.