Alvimopan
Entereg (alvimopan) is a peripherally acting mu-opioid receptor antagonist used to restore normal bowel function after surgery or in patients taking opioid pain medications. It works by blocking opioid receptors in the gastrointestinal tract without affecting central nervous system pain relief.
Entereg is used to treat postoperative ileus and opioid-induced constipation by blocking opioid receptors in the gut.
Key facts at a glance
- RxNorm
- 482748
- Generic
- Entereg
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Entereg is indicated for the treatment of postoperative ileus (reduced bowel movement after abdominal surgery) and for the reversal of opioid-induced bowel dysfunction in patients with chronic non-cancer pain requiring opioid therapy.
Entereg is a peripherally acting mu-opioid receptor antagonist. It selectively blocks opioid receptors in the gastrointestinal tract, preventing opioids from slowing intestinal motility and secretion, thereby restoring normal bowel function while preserving central nervous system pain relief from opioids.
Entereg has a restricted distribution program (REMS) due to potential cardiovascular risks. It is approved for short-term hospital use only (up to 7 doses for postoperative ileus). It should not be used in patients who have taken opioids for more than 7 consecutive days before surgery, as this increases cardiovascular risk. Common side effects include dyspepsia, hypokalemia, and procedural pain.
Official drug label
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This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy