Alvimopan
Alvimopan is a short-term, hospital-only opioid blocker that works in the gut to help bowel function recover faster after bowel surgery.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 4 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Alvimopan (Entereg) is a specialist, hospital-only medicine that helps the bowels wake up faster after surgery that removes part of the bowel and joins the ends back together. It works by blocking opioid receptors in the gut without undoing the pain relief opioids give in the brain, and it is available as a generic. Over its short course most people tolerate it well, and indigestion or an upset stomach is the side effect people notice most. It carries a boxed warning for a possible heart attack risk with long-term use, so it is capped at 15 doses through a restricted hospital program (REMS), and any chest pain should be reported right away.
Clinical pearls
- Opioid pain medicine taken more than 7 days straight before surgery rules alvimopan out, so tell your surgeon beforehand.
- Even a few opioid doses in the week before surgery can make its stomach and bowel side effects stronger.
- The first dose comes shortly before surgery, and doses stop when you leave the hospital; food does not matter.
- Mention severe liver disease or end-stage kidney disease before surgery, since alvimopan is not recommended with either.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Alvimopan is for short-term hospital use only. In one 12-month study of people taking opioids for long-term pain, more heart attacks (myocardial infarctions) occurred with alvimopan than with placebo. A direct cause has not been proven. No increased heart attack risk was seen in short-term studies, including in surgery patients.
Because of this possible risk, alvimopan is limited to no more than 15 doses and is available only through enrolled hospitals. Report chest pain or other heart attack symptoms to your care team right away.
Patient information guide A plain-language walkthrough of Alvimopan, written from its FDA label.
What Alvimopan is used for
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Alvimopan is used in the hospital after certain bowel surgeries.
- Alvimopan capsules (oral) speed up recovery of upper and lower digestive tract function after surgeries that include partial bowel resection with primary anastomosis.
How Alvimopan works
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Opioid pain medicines slow the gut, which can prolong postoperative ileus (a stalled digestive tract after surgery). Alvimopan blocks opioid receptors in the digestive tract, so the gut is less affected by opioids.
It does this without reversing the pain relief opioids provide in the brain.
Alvimopan dosage
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Alvimopan is a capsule taken by mouth, in the hospital only. You get one dose before surgery, then twice-daily doses after surgery until discharge, for up to 7 days and no more than 15 doses total.
- It can be taken with or without food.
- Your hospital team gives each dose, so missed-dose planning is handled by them.
Dosing details from the FDA-approved label
From the Alvimopan prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Adults (hospital use only)
- 12 mg administered 30 minutes to 5 hours prior to surgery followed by 12 mg twice daily beginning the day after surgery until discharge
- Maximum: Maximum of 7 days; patients should not receive more than 15 doses
- Can be taken with or without food
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION For hospital use only. The recommended adult dosage of alvimopan capsules is 12 mg administered 30 minutes to 5 hours prior to surgery followed by 12 mg twice daily beginning the day after surgery until discharge for a maximum of 7 days. Patients should not receive more than 15 doses of alvimopan capsules. Alvimopan capsules can be taken with or without food [see Clinical Pharmacology ( 12.3 )] . • For hospital use only. ( 2 ) • The recommended dosage is 12 mg administered 30 minutes to 5 hours prior to surgery followed by 12 mg twice daily beginning the day after surgery until discharge for a maximum of 7 days. Patients should not receive more than 15 doses of alvimopan capsules. ( 2 )
Read the full Dosage and Administration section on DailyMed →
Alvimopan side effects
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The most common side effect in trials was:
Common side effects
- Dyspepsia (indigestion or upset stomach)
When to get medical help
- Tell your care team right away about new or worsening belly pain, cramping, nausea, vomiting or diarrhea.
- Report chest pain or other heart attack symptoms immediately.
- Tell staff if you have liver or kidney problems and notice stomach or bowel symptoms, because the medicine may need to be stopped.
Alvimopan warnings and precautions
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- Possible heart attack risk with long-term use. It is limited to 15 doses in enrolled hospitals.
- More stomach and bowel side effects can occur if you were recently on opioids.
- Not recommended with severe liver impairment, end-stage kidney disease, complete bowel obstruction, or pancreatic or gastric anastomoses.
Alvimopan interactions
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Few interactions were described, but recent opioid use matters most.
- Opioids for more than 7 days in a row before surgery: alvimopan should not be used.
- Opioids in the week before surgery: you may be more sensitive and need monitoring.
- Intravenous morphine: no dose change needed.
- Acid blockers and antibiotics: no dose change needed.
Interactions listed in the FDA-approved label
From the Alvimopan prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Intravenous morphine: Coadministration of alvimopan does not appear to alter the pharmacokinetics of morphine and its metabolite, morphine-6-glucuronide, to a clinically significant degree when morphine is administered intravenously. Dosage adjustment for intravenously administered morphine is not necessary when it is coadministered with alvimopan.
- Acid blockers (proton pump inhibitors, histamine-2 (H2) receptor antagonists): A population pharmacokinetic analysis suggests that the pharmacokinetics of alvimopan were not affected by concomitant administration of acid blockers. No dosage adjustments are necessary in patients taking acid blockers with alvimopan.
- Antibiotics: A population pharmacokinetic analysis suggests that the pharmacokinetics of alvimopan were not affected by concomitant administration of antibiotics. No dosage adjustments are necessary in patients taking antibiotics with alvimopan.
Read the label’s full interactions text
7 DRUG INTERACTIONS 7.1 Effects of Alvimopan on Intravenous Morphine Coadministration of alvimopan does not appear to alter the pharmacokinetics of morphine and its metabolite, morphine-6-glucuronide, to a clinically significant degree when morphine is administered intravenously. Dosage adjustment for intravenously administered morphine is not necessary when it is coadministered with alvimopan. 7.2 Effects of Concomitant Acid Blockers or Antibiotics A population pharmacokinetic analysis suggests that the pharmacokinetics of alvimopan were not affected by concomitant administration of acid blockers (proton pump inhibitors (PPIs), histamine-2 (H 2 ) receptor antagonists) or antibiotics. No dosage adjustments are necessary in patients taking acid blockers or antibiotics with alvimopan.
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Alvimopan
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- Do not use if you took opioids for more than 7 days in a row right before surgery.
- Not recommended with severe liver problems or end-stage kidney disease.
- Mild-to-moderate liver problems or any kidney impairment: closer monitoring.
- Japanese patients: closer monitoring for side effects.
- Pregnancy: data are limited.
- Breastfeeding: discuss benefits and risks with your doctor.
- Children: not established as safe or effective.
- Older adults: no dose change needed.
What Alvimopan does in the body
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In healthy volunteers, alvimopan reduced the slowing of small and large bowel movement caused by codeine. It did not reduce codeine's slowing of stomach emptying. At twice the approved dose for 7 days, it did not meaningfully affect the heart's QT interval (an electrical measurement).
How your body processes Alvimopan
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Only a small share of an oral dose is absorbed. Blood levels peak at about 2 hours. A high-fat meal lowers absorption somewhat, but the label allows dosing with or without food after the first dose, which was given fasting in trials.
Alvimopan is cleared mainly through bile, with about 35% of clearance through the kidneys. Gut bacteria convert it to an active metabolite. Its half-life ranged from 10 to 17 hours.
How to store Alvimopan
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Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F) .
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Alvimopan
54 supplements and herbal products have documented interactions with Alvimopan in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 2
- Moderate · 35
- Minor · 17
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Alvimopan: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Alvimopan — the kind of thing our pharmacy team would talk through with you at the counter.
What is alvimopan for?
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How will I take it?
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Why is it limited to 15 doses?
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What side effects should I expect?
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Can I take it if I've been on opioid pain medicine?
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Is it safe with liver or kidney problems?
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Is Alvimopan available over the counter?
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When was Alvimopan first available?
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Who makes Alvimopan?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Alvimopan on HelloPharmacist
Alvimopan forms and strengths (how it comes)
Alvimopan is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Capsule
How this form is used
- Alvimopan capsules are used to speed recovery of upper and lower digestive function after surgery that includes partial bowel resection with primary anastomosis.
- Alvimopan capsules are for hospital use only.
- Alvimopan capsules are given once before surgery, then twice daily after surgery until discharge, for up to 7 days.
- Patients should not receive more than 15 doses of alvimopan capsules.
- Alvimopan capsules can be taken with or without food.
Alvimopan on the U.S. market: products, makers and brands
How Alvimopan appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
4 companies list 4 Alvimopan product records with the FDA, mostly as capsule; the earliest marketing or approval year on record is 2008. Brand names on the directory include Entereg; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (1) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
Compare Alvimopan products
A representative set of FDA-listed product records for Alvimopan — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Capsule | ||||
| 12 mg | Oral | Actavis Pharma, Inc. | ANDA | View NDC → |
| 12 mg | Oral | Golden State Medical Supply, Inc. | ANDA | View NDC → |
| 12 mg | Oral | Hikma Pharmaceuticals USA Inc. | ANDA | View NDC → |
| 12 mg | Oral | Par Health USA, LLC | ANDA | View NDC → |
Showing 4 of 4 products — FDA National Drug Code Directory. See every product, package size and price: browse all 4 Alvimopan NDCs →
Alvimopan side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Alvimopan — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Alvimopan in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Alvimopan FDA approval history
How Alvimopan went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Alvimopan recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Alvimopan recalls since July 2021.
✅No Alvimopan recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 480639 1 dose form · 1 strength
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Dose form (SCDF) Oral Capsule RxCUI 799834In current FDA listingsClinical drug / strength (SCD) 12 MGRxCUI 799835
Look up RxCUI 480639 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Alvimopan supply and shortage status
Whether Alvimopan is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Alvimopan brand names
Alvimopan is sold under one brand name in the FDA directory — Entereg. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Alvimopan: manufacturers and labelers
4 companies list Alvimopan products with the FDA. By number of product records, the largest are Actavis Pharma, Inc., Golden State Medical Supply, Inc., Hikma Pharmaceuticals USA Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Alvimopan drug class (RxNorm)
Alvimopan belongs to the Opioid Antagonist class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Alvimopan page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Actavis Pharma, Inc. is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →