Methylnaltrexone and alvimopan: economic management of opioid-induced bowel dysfunction

The occurrence of opioid-induced bowel dysfunction is common in the postoperative period and in chronic pain conditions. This debilitating adverse effect involves the activation of peripheral opioid receptors causing delayed recovery of normal colonic motility, prolonged postoperative ileus and increased morbidity. This translates into increased lengths of hospitalization and significant added attendant healthcare costs. Methylnaltrexone and alvimopan (Entereg, Eli Lily & Co.) are the first selective antagonists of gastrointestinal opioid receptors. Recent studies have shown their ability to reverse opioid-induced bowel dysfunction without reversing analgesia or precipitating CNS withdrawal signs in nonsurgical chronic pain patients receiving opioids. In addition, clinical studies with alvimopan suggest that it may normalize bowel function without blocking opioid analgesia in abdominal laparotomy patients with opioid-related postoperative ileus. These drugs may have clinical utility with an economic impact in managing opioid-induced bowel dysfunction.