Which of the following medications is MOST appropriate for treating postoperative ileus?
A. Alvimopan ✔
B. Eluxadoline X
C. Loperamide X
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Postoperative ileus stems from various factors disrupting the normal gut motility after surgery. These include inflammation triggered by surgical trauma, inhibitory neural reflexes, neurohumoral peptides like nitric oxide, and the pharmacological effects of opioids, which notably slow down gastrointestinal activity. Peripherally acting μ-opioid receptor antagonists can be used to reduce postoperative ileus without reducing analgesic efficacy, as they do not typically cross the blood–brain barrier. Agents include methylnaltrexone, naloxegol, and naldemedine, which are approved for various types of opioid-induced constipation, and alvimopan, which is approved for postoperative ileus.
Alvimopan is a competitive antagonist of μ-opioid receptors in the gastrointestinal system. Early studies on alvimopan showcased its ability to hasten gastrointestinal recovery after surgeries like bowel resections and abdominal hysterectomies. Despite its promising outcomes, concerns about potential cardiovascular complications (eg, myocardial infarction) prompted the US Food and Drug Administration to restrict alvimopan’s use to hospital settings via a risk evaluation and mitigation strategies (REMS) program.
Loperamide is an μ-opioid receptor agonist that acts preferentially on peripheral receptors due to extensive first-pass metabolism and efflux by P-glycoproteins, preventing it from crossing the blood–brain barrier. Loperamide is used in the management of diarrhea. Eluxadoline is a μ- and κ-opioid receptor agonist and a δ-opioid receptor antagonist used for the treatment of diarrhea and abdominal pain in patients with diarrhea-predominant irritable bowel syndrome.
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Date of last update: March 18, 2025