Alvimopan, known by its brand name Entereg, is a prescription medication administered within a hospital setting. This medication helps patients regain normal bowel function more quickly after specific surgical procedures.
Accelerating Gut Recovery After Surgery
Following certain surgical procedures, many patients experience a temporary condition known as postoperative ileus. This condition involves a temporary paralysis of the bowels, where normal muscular contractions slow down or stop. Opioid pain medications, while effective for managing post-surgical discomfort, can unfortunately worsen this slowdown by further inhibiting bowel movement.
Alvimopan is specifically used to counteract this opioid-induced slowing of the gut. By helping the digestive system resume its normal function sooner, the medication reduces the time it takes for patients to pass gas or have a bowel movement. A quicker return of bowel function often allows patients to recover more comfortably and may contribute to a shorter overall stay in the hospital.
How Alvimopan Works
Alvimopan functions as a peripherally acting mu-opioid receptor antagonist, often abbreviated as PAMORA. Opioid pain medications bind to mu-opioid receptors throughout the body, including in the gut. When opioids bind to receptors in the gut, they slow down the muscular contractions responsible for digestion.
Alvimopan works by selectively blocking these mu-opioid receptors found only in the digestive system, preventing opioid pain medications from binding to and activating them. Alvimopan does not readily cross the blood-brain barrier, meaning it does not interfere with the pain-relieving effects of opioids in the brain. This targeted action allows it to alleviate opioid-induced gut dysfunction without compromising pain control.
Administration and Patient Considerations
Alvimopan is administered exclusively in a hospital environment under a controlled protocol. The typical dosing schedule involves a single dose given before surgery. Following the initial dose, administration usually continues twice daily for a limited duration, often for up to seven days or until discharge from the hospital. The total number of doses administered is usually capped, such as 15 doses.
A significant consideration for alvimopan use involves a patient’s prior opioid exposure. Patients who have been taking opioid medications regularly for more than seven consecutive days immediately preceding their surgery should not receive alvimopan. Administering the medication in such cases carries a risk of precipitating opioid withdrawal symptoms, which can be severe and uncomfortable. Healthcare providers carefully assess a patient’s medication history to ensure safe and appropriate use.
Potential Side Effects
Common reported side effects include dyspepsia, which is a sensation of indigestion or discomfort in the upper abdomen. Other mild effects might involve abdominal pain or nausea. Patients are encouraged to report any new or worsening symptoms to their healthcare team.
A historical concern regarding alvimopan involved a potential, although small, increased risk of heart attack observed in some clinical trials. This finding led to specific restrictions on its use and the implementation of a Risk Evaluation and Mitigation Strategy (REMS) program. This program ensures that alvimopan is only available through a restricted distribution system to manage this potential risk. Patients should remain vigilant for any symptoms such as chest pain or discomfort and promptly inform their medical staff.