Year-end Sale % OFF 
Abstract
Postoperative ileus (POI) and constipation are common secondary effects of opioids and carry significant clinical and economic impacts. μ-Opioid receptors mediate opioid analgesia in the central nervous system (CNS) and gastrointestinal-related effects in the periphery. Peripherally acting μ-opioid receptor antagonists (PAMORAs) block the peripheral effects of opioids in the gastrointestinal tract, while maintaining opioid analgesia in the CNS. While most are not approved for POI or postoperative opioid-induced constipation (OIC), PAMORAs have a potential role in these settings via their selective effects on the μ-opioid receptor. This review will discuss recent clinical trials evaluating the safety and efficacy of PAMORAs, with a focus on alvimopan (Entereg®) and methylnaltrexone (Relistor®) in patients with POI or postoperative OIC. We will characterize potential factors that may have impacted the efficacy observed in phase 3 trials and discuss future directions for the management and treatment of POI.
Highlights
Postoperative IleusPostoperative ileus (POI) is defined as a delay of normal gastrointestinal (GI) motility after surgery and can be secondary to surgical stress responses, neurohormonal dysfunction, inflammation, fluid and electrolyte imbalances, and opioids.[1–3] Clinical features of POI include bloating, abdominal distention, nausea, vomiting, delay in oral intake, and pain.[4]
No cardiac adverse events (AEs) were reported and no safety signals or pattern of concern was visualized by ECG,[41] suggesting that methylnaltrexone exposure does not share the same cardiac risks and precautions as alvimopan. These results demonstrated that SC methylnaltrexone was effective in improving GI recovery and was generally welltolerated in patients with acute-onset opioid-induced constipation (OIC).[41]
This study demonstrated that SC methylnaltrexone provided consistent long-term treatment for OIC without new safety concerns, suggesting that methylnaltrexone is safe and effective to use in the long term.[47]
Summary
Postoperative ileus (POI) is defined as a delay of normal gastrointestinal (GI) motility after surgery and can be secondary to surgical stress responses (i.e., bowel manipulation and/or resection), neurohormonal dysfunction, inflammation, fluid and electrolyte imbalances, and opioids (both endogenous and exogenous).[1–3] Clinical features of POI include bloating, abdominal distention, nausea, vomiting, delay in oral intake, and pain.[4]. BID twice daily, EOD every other day, GI gastrointestinal, MI myocardial infarction, OIC opioid-induced constipation, POI postoperative ileus, QD once daily, REMS risk evaluation and mitigation strategy, SC subcutaneous patients undergoing bowel resection.[36]. This study demonstrated that patients treated with alvimopan incurred significantly greater charges for medical and surgical supplies, pathology and cytology services, operating room charges, and therapy charges (P < 0.05).[38] These increases in costs were largely associated with surgical time and a shift in hospitalwide accelerated recovery efforts; they may be due to differences in surgical complexity between groups.[38]. This suggests that patient selection is important in deciding who should receive ERAS interventions, including PAMORAs, such as alvimopan.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
