The Safety of Per Os Naloxone and its Efficacy in Resolving Postoperative Ileus in Patients Undergoing Spine Surgery

INTRODUCTION: Postoperative ileus (POI) is a common complication after spine surgery which often leads to increased length of stay and associated sequelae. While the use of laxatives and supportive therapy can be effective in resolving the symptoms, the use of oral mu-opioid receptor antagonists has not been evaluated in this field. Per os (PO) naloxone (Narcan) is a mu-opioid receptor antagonist with limited systemic absorption with effects mainly confined to the gastrointestinal tract. The aim of this study is to evaluate the safety and potential effectiveness of oral naloxone and its role in resolving ileus in postoperative spine patients. METHODS: A descriptive study of patients who had received PO naloxone after spine surgery was undertaken. A total of 29 consecutive patients were identified between 2015 and 2018. Postoperative ileus was subdivided into postoperative constipation, ileus, prolonged ileus, and recurrent ileus. To assess for withdrawal symptoms, we collected pain scores, opioid intake, and vital signs before and after PO naloxone administration. Primary endpoint was time to resolution of ileus and discharge. Patients were followed for 3 mo to record any long-term medication adverse events. RESULTS: The mean age was 62 yr old; 18 were male (62.1%) and 14 (48.3%) were chronic opioid users. All patients received opioids postoperatively as part of their analgesia therapy. There was no significant difference between pre- and post-PO naloxone pain scores, opioid intake, or vital signs to indicate withdrawal symptoms. A total of 26 patients (89.7%) had resolution of their POI the same day as PO naloxone administration and two more the following day. No complications were directly linked to PO naloxone intake. CONCLUSION: In this study, PO naloxone was safe and effective in relieving symptoms associated with POI after spine surgery. Further prospective, cohort or randomized controlled studies are needed to validate the value of PO naloxone in reducing length of stay and resolving POI.