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Xifaxan rifaximin 550 mg Tablet, 360-count — NDC 55154-6777-08 package photo
Label image from the product's FDA listing (DailyMed) — may show a different pack size or an older label revision.

Xifaxan rifaximin 550 mg Tablet, 360-count — NDC 55154-6777-8 (Billing 55154-6777-08)

by Cardinal Health 107, LLC · 360 TABLET in 1 BOTTLE, PLASTIC

This is a package of 360 tablets of Xifaxan rifaximin 550 mg Tablet from Cardinal Health 107, LLC, marketed since May 2010 and currently FDA-listed. It is this product's only package size.

NDC 55154-6777-08
🏷️ FDA NDC (as labeled) 55154-6777-8 billing pads the package segment with a zero
Rx only Brand On market Non-controlled ⇄ Compare with another NDC
🗂️ FDA directory synced Oct 1, 2026 · this listing last changed Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

This page is curated, coded, and maintained by

Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

NDC database record

One package, one record: these facts belong to NDC 55154-6777-8 alone.

Record
FDA NDC Directory package listing · Human prescription drug
Code segments
55154 labeler · 6777 product · 8 package
Package marketed since
May 1, 2010
Sample package
No — commercial package
Listing certified through
Dec 31, 2026
Billing quantity
360 EA per package
Barcode (UPC)
0355154677784
FDA record last changed
Jul 24, 2026

Identity & classification

Regulatory identifiers FDA, NLM and CMS codes for this package

FDA NDC (as labeled) 55154-6777-8
Product NDC 55154-6777
11-digit billing NDC 55154677708
NCPDP billing unit EA — each (per item)
RxCUI 856664, 856666
UNII L36O5T016N
UPC 0355154677784
Application # NDA021361
SPL Set ID 7afafa63-3236-4212-9589-045db6b01c0b
Established class (EPC) Rifamycin Antibacterial
Chemical class Rifamycins
DEA schedule Non-controlled
Marketing category NDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2010-05-01
Route ORAL
Dosage form TABLET
Substance RIFAXIMIN
TE code (Orange Book) AB · RLD · RS

Drug-database identifiers Medi-Span GPI and First Databank GCN / HICL / AHFS classification

GCN Seq No 066295
GCN 28530
HICL code 020401
Ingredient (HICL) Rifaximin
HIC1 code W
Therapeutic class — broad (HIC1) Anti-Infecting Agents
HIC2 code W9
Therapeutic class — intermediate (HIC2) Antibiotics (Continued 1)
HIC3 code W9C
Therapeutic class — specific (HIC3) Rifamycins And Related Derivative Antibiotics
AHFS code 08:12.28.30
AHFS class Rifamycin Antibiotics
FDB label name XIFAXAN 550 MG TABLET
FDB brand name Xifaxan
Legend status F — Federal legend — prescription drug or device
Quick answers
  • GSN (GCN sequence number): 066295
  • GCN: 28530
  • HICL (First Databank): 020401
  • AHFS class code: 08:12.28.30
  • RxCUI (RxNorm): 856664
Why two NDCs? The FDA registers this code as 55154-6777-8 — a 5-4-1 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the package segment → 55154-6777-08. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

RxNorm drug class

This medicine belongs to the Rifamycin Antibacterial class.

Pharmacologic class Rifamycin Antibacterial
Drug family (ATC) Antibiotics, Other antibiotics for topical use
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

Clinical

Label name XIFAXAN 550 MG TABLET Ingredient Rifaximin
📖 What it is MedlinePlus · NLM

Rifaximin is used to treat traveler's diarrhea caused by certain bacteria, hepatic encephalopathy (changes in how a person thinks, acts, or feels because their liver is not working properly to remove toxins) and irritable bowel syndrome (with diarrhea). Rifaximin is in a class of medications called antibiotics. Rifaximin treats traveler's diarrhea and irritable bowel syndrome by stopping the growth of the bacteria that cause diarrhea. Rifaximin treats hepatic encephalopathy by stopping the growth of bacteria that produce toxins and that may worsen liver disease. Rifaximin will not work to tre...

Read the full MedlinePlus article ↗
📗 Our plain-language guide HelloPharmacist
  • Rifaximin (Xifaxan tablets) treats travelers’ diarrhea caused by certain E. coli, lowers the chance that hepatic encephalopathy comes back, and treats IBS-D in adults. Which one ap...
  • No. You can take it with or without food. Just follow the schedule on your label, since the number of days and doses a day differ by condition.
  • Common ones include headache, nausea, dizziness, fatigue, and swelling in the legs, depending on the condition. If you take it for hepatic encephalopathy, side effects like swellin...
  • Call if diarrhea gets worse, lasts more than 1 to 2 days on treatment, or comes with fever or blood. Also call for watery diarrhea after you finish, which can show up weeks later....
📖 Read our full Rifaximin guide →
7
Nutrient depletion considerations

Rifaximin may be associated with lower levels of 7 nutrients — worth a chat with your pharmacist, not a cause for alarm.

🧪 Full Rifaximin nutrient depletion report →
An association is not a deficiency. Educational only — don't start or stop anything without professional guidance.
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer eachPer package
Retail pharmacies payNADAC · weekly Not in the retail survey — common for institutional, discontinued, or low-volume packs.
Medicaid paysCMS SDUD · 12 mo No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data.
Medicare drug plans payPart D · Q2 2026 $66.02 $23,765.94 / 360 tablets
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

Packaging — all sizes for this product

Package NDCDescription Marketing startMarketing endStatus
55154-6777-08 You're viewing this Main listing 360 TABLET in 1 BOTTLE, PLASTIC 2010-05-01 — Active

Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Xifaxan 550 mgthis 55154-6777-08 Cardinal 360 tablets — AB FDA listed —
Xifaxan 550 mg 65649-0303-01 Salix 6 tablets — AB FDA listed —
About this product: this is the brand-name version. Some generic versions are approved by the FDA, but we could not confirm current pharmacy availability from our pricing/market data.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
2004
First FDA approval
May 2004
📍
2026
Currently FDA-listed
22 years listed
🛡️
2029
Latest patent/protection listed
not a guaranteed launch date
🔒Generic approved by FDA, but pharmacy availability is not confirmed

The FDA lists approved generic versions of this medicine, but that does not always mean a pharmacy can get one today. Patent rules, launch agreements, supply and pricing can affect when generics actually arrive.

🛡️ Latest patent/protection date listed: FDA patent/protection data lists protections through Oct 2029. This may affect when a full generic version becomes widely available, but it is not a guaranteed launch date.
📅 FDA approved May 25, 2004 RLD RS ⏳ ~3 yr to latest listed protection

Why the date isn’t exact: Generic timing can change because patents may be challenged, settled, licensed, added, removed, or worked around with a narrower label — and FDA approval does not always mean a pharmacy can get the generic today.

Patents & exclusivity — FDA Orange Book
US 7928115 — method of use (U-1121)
US 8193196 — drug substance (U-1707)
US 8193196 — drug substance (U-1708)
US 8309569 — method of use (U-1708)
US 8309569 — method of use (U-1707)
US 8741904 — drug substance (U-1708)
US 8741904 — drug substance (U-1707)
US 8829017 — method of use (U-1562)
US 8642573 — method of use (U-1481)
US 9421195 — method of use (U-1481)
US 8969398 — method of use (U-1481)
US 8946252 — method of use (U-1481)
US 10335397 — method of use (U-2579)
US 10456384 — method of use (U-2643)
US 10456384 — method of use (U-2644)
US 9629828 — method of use (U-1994)
US 10314828 — method of use (U-1481)
US 10703763 — method of use (U-2847)
US 10703763 — method of use (U-1708)
US 10765667 — method of use (U-2644)
US 10765667 — method of use (U-2643)
US 10709694 — method of use (U-2579)
US 10703763 — method of use (U-2848)
US 8741904 — drug substance (U-2848)
US 8741904 — drug substance (U-2847)
US 11779571 — method of use (U-3706)
US 11564912 — method of use (U-3511)
US 11564912 — method of use (U-3512)
US 8518949 — drug product
US 9271968 — drug product
US 8193196 — drug substance
US 8518949 — drug product
US 9271968 — drug product
2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028
Today
LOE
Substance patent Formulation patent Method-of-use patent Exclusivity Pediatric +6mo
🏛️FDA exclusivity
FDA-granted marketing protection. It’s separate from patents and may be shorter than patent protection.
🧪Product / substance patents
Patents covering the active ingredient, product, formulation, or related drug features.
🎯Method-of-use patents
Patents covering specific approved uses. These can sometimes be carved out with a “skinny label,” but not always.
🛈 What do these terms mean?
Patent
Legal protection listed in the Orange Book that may delay generic approval or launch. Issued by the U.S. Patent & Trademark Office.
Substance patent
Covers the active drug molecule itself — the hardest to design around. A generic generally can’t launch until it expires.
Formulation (product) patent
Covers a specific formulation or dosage form. A generic can sometimes work around it with a different formulation.
Method-of-use patent
A patent covering one specific approved use of the drug — not necessarily the whole molecule. A generic can sometimes launch with a “skinny label” that carves out the protected use and keeps the others.
Skinny label
A generic label that omits a still-patented use when the FDA allows it — letting a generic reach the market for the unprotected uses.
Exclusivity
FDA-granted marketing protection, separate from patents — e.g. 5-yr new chemical entity, 7-yr orphan drug, or a +6-month pediatric extension.
Paragraph IV
A generic applicant’s formal challenge to a listed patent. It can potentially lead to earlier generic entry, but often involves litigation or a settlement.
RLD / RS
Reference Listed Drug — the brand product the FDA uses as the reference for generic applications. Reference Standard — the product the FDA expects generics to compare against in bioequivalence testing.
TE / AB rating
FDA therapeutic-equivalence rating. An AB rating generally means the FDA considers a generic therapeutically equivalent to — and substitutable for — the brand.
LOE (loss of exclusivity)
The latest patent or exclusivity currently listed — the loss-of-exclusivity / latest-listed-protection date shown on this page. Paragraph-IV challenges and settlements can move the real date earlier; FDA approval and a manufacturer’s decision to market can move it later.

Built from the FDA Orange Book. The bars above are scaled to each protection’s expiry; the red LOE marker is the last one to lapse.

Listed patents (33)
PatentTypeUse codeExpires
US 7928115 ↗ Method of use U-1121 Jul 24, 2029
US 8193196 ↗ Drug substance U-1707 Sep 2, 2027
US 8193196 ↗ Drug substance U-1708 Sep 2, 2027
US 8309569 ↗ delist req. Method of use U-1708 Jul 18, 2029
US 8309569 ↗ delist req. Method of use U-1707 Jul 18, 2029
US 8741904 ↗ Drug substance U-1708 Feb 27, 2026
US 8741904 ↗ Drug substance U-1707 Feb 27, 2026
US 8829017 ↗ Method of use U-1562 Jul 24, 2029
US 8642573 ↗ Method of use U-1481 Oct 2, 2029
US 9421195 ↗ Method of use U-1481 Jul 24, 2029
US 8969398 ↗ Method of use U-1481 Oct 2, 2029
US 8946252 ↗ Method of use U-1481 Jul 24, 2029
US 10335397 ↗ Method of use U-2579 Jul 24, 2029
US 10456384 ↗ Method of use U-2643 Feb 26, 2029
US 10456384 ↗ Method of use U-2644 Feb 26, 2029
US 9629828 ↗ Method of use U-1994 Jul 24, 2029
US 10314828 ↗ Method of use U-1481 Jul 24, 2029
US 10703763 ↗ Method of use U-2847 Feb 27, 2026
US 10703763 ↗ Method of use U-1708 Feb 27, 2026
US 10765667 ↗ Method of use U-2644 Feb 26, 2029
US 10765667 ↗ Method of use U-2643 Feb 26, 2029
US 10709694 ↗ Method of use U-2579 Jul 24, 2029
US 10703763 ↗ Method of use U-2848 Feb 27, 2026
US 8741904 ↗ Drug substance U-2848 Feb 27, 2026
US 8741904 ↗ Drug substance U-2847 Feb 27, 2026
US 11779571 ↗ Method of use U-3706 Feb 26, 2029
US 11564912 ↗ Method of use U-3511 Feb 26, 2029
US 11564912 ↗ Method of use U-3512 Feb 26, 2029
US 8518949 ↗ Drug product — Feb 27, 2026
US 9271968 ↗ Drug product — Feb 27, 2026
US 8193196 ↗ Drug substance — Sep 2, 2027
US 8518949 ↗ Drug product — Feb 27, 2026
US 9271968 ↗ Drug product — Feb 27, 2026
Common questions
Is there a generic version of XIFAXAN 550 MG TABLET?
Yes — an FDA-approved generic equivalent is listed in the FDA Orange Book for XIFAXAN 550 MG TABLET. See the alternatives section for substitutable, lower-cost products.
The FDA approved a generic — why can’t I get it at my pharmacy yet?
FDA approval and pharmacy availability are two different things. The FDA can approve a generic years before it actually reaches pharmacies, because the brand company may still hold patents or have a settlement that delays the launch. A manufacturer also has to choose to make and sell it, and have supply ready. So a drug can be “FDA-approved generic exists” and still be brand-only at the counter today.
Why do different websites show different generic release dates?
Generic availability is not based on one single date. Some sources use the first exclusivity expiration, some use the last product patent, and others use the latest method-of-use patent. Patent challenges, settlements, licenses, and label carve-outs can also change the real-world launch date. This page shows the underlying Orange Book dates so you can see why estimates may differ.
What does “FDA listed” mean?
It means the product appears in the FDA’s official NDC directory. That’s a good sign a product exists and is intended for the U.S. market, but on its own it does not confirm a pharmacy can fill it today. Where we have recent retail pricing data (NADAC) for a product, we label it “Availability likely” instead.
What does a patent or protection date mean here?
It’s the latest date currently listed in the FDA Orange Book for a patent or exclusivity on the brand product. It can affect when a full generic version becomes widely available — but it is not a guaranteed generic launch date. Generics sometimes arrive earlier (through a settlement or patent challenge) or later (a manufacturer still has to make and sell one).
What does “current Orange Book estimate” mean?
It means we are using the latest patent and exclusivity dates currently listed in the FDA Orange Book. It is not a guaranteed launch date.
Can a generic come out before the last patent expires?
Sometimes. A generic company may challenge a patent, settle with the brand manufacturer, receive a license, or obtain approval with a narrower label that avoids a patented use. In other cases, the last listed protection may delay full-label generic competition.
Can a generic come out after the listed dates?
Yes. Even after patents or exclusivity expire, a generic still needs FDA approval and a manufacturer must choose to market it. Supply, litigation, business decisions, or regulatory issues can delay actual availability.
What is the difference between patents and exclusivity?
Patents are legal protections usually issued by the U.S. Patent and Trademark Office. FDA exclusivity is marketing protection granted by the FDA. They are separate, and either one can affect generic timing.
Why are there multiple patent dates?
One drug can have several patents covering different things: the active ingredient, a formulation, a manufacturing process, or a specific approved use. That is why a page may show several expiration dates instead of one simple generic date.
Built from FDA Orange Book patent and exclusivity data. Dates are refreshed from public FDA data when available; the marker is max(latest patent expiry, latest exclusivity expiry). Paragraph-IV settlements and first-filer 180-day exclusivity can shift the real date; a method-of-use patent may allow an earlier skinny-label generic for non-protected indications. Generic launch timing is an estimate, not a guarantee.
Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

What it looks like

Color Pink
ShapeOval
Imprintrfx
Size19 mm
ScoringNot scored
One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.
Where does this data come from?
Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.

  • UNII 1K09F3G675
    Ferric oxide red is an inorganic iron compound used as a colorant in medicines. It gives tablets, capsules, or other dosage forms a red or reddish tint for identification and appearance.
  • UNII GSY51O183C
    Glyceryl palmitostearate is a waxy fat made from glycerin and fatty acids. It acts as a binder and lubricant in tablets and capsules, helping hold ingredients together and allowing smooth manufacturing.
  • UNII OP1R32D61U
    Microcrystalline cellulose is a purified form of cellulose, a natural fiber from plant sources. It acts as a binder and filler in tablets and capsules, helping hold ingredients together and give the medicine its shape and size.
  • UNII 3WJQ0SDW1A
    Polyethylene glycol is a synthetic liquid or solid polymer used in medicines as a solvent, lubricant, and humectant. It helps dissolve active ingredients, reduces friction during manufacturing, and retains moisture in the final product.
  • UNII 532B59J990
    Polyvinyl alcohol is a synthetic polymer made from plant-derived materials. It's used as a binder to hold ingredients together, a film-former in coatings, and a thickener in liquid formulations.
  • UNII ETJ7Z6XBU4
    Silicon dioxide is a naturally occurring mineral used as a glidant and anti-caking agent. It helps powder ingredients flow smoothly and prevents clumping during manufacturing and storage.
  • UNII 5856J3G2A2
    A starch-based powder made from potatoes and processed with sodium. It acts as a disintegrant, helping the tablet or capsule break apart quickly in the stomach so the medicine can be absorbed.
  • UNII 7SEV7J4R1U
    A powder made from a naturally occurring mineral. In medicines, talc works as a glidant and anti-caking agent, helping tablets and capsules flow smoothly during manufacturing and preventing clumping.
  • UNII 15FIX9V2JP
    Titanium dioxide is a bright white mineral powder commonly used as a colorant and opacifying agent. It makes pills and tablets white or lighter in color and helps make coatings non-transparent.

9 inactive ingredients listed in the exact product block matched to this NDC.

Where does this data come from?
Data sourced from official FDA Structured Product Labeling (SPL) via DailyMed — ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

Manufacturer & labeler

LabelerCardinal Health 107, LLC
Application holderSALIX PHARMACEUTICALS INC
FDA applicationNDA021361 (NDA)
Labeler code55154
First marketedMay 2010
Product typeHuman Prescription Drug
Portfolio477 products on file

More NDCs from Cardinal Health 107, LLC labeler code 55154

The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Very long sections are excerpted here and marked; the full text is on DailyMed (linked in the sources below). Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage ⏱️ Dosage and Administration 💊 Dosage Forms and Strengths ⛔ Contraindications ⚠️ Warnings and Cautions 🤒 Adverse Reactions 🔄 Drug Interactions 👥 Use in Specific Populations 🤰 Pregnancy 🧒 Pediatric Use 🧓 Geriatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 🧬 Mechanism of Action 📦 How Supplied / Storage and Handling 📋 Description 💬 Information for Patients 🧬 Pharmacokinetics 🔬 Clinical Studies 🧪 Nonclinical Toxicology 📄 Carcinogenesis, Mutagenesis, Impairment of Fertility 📄 Package Label / Principal Display Panel
🎯 Indications and Usage ~2 min read ▾

1 INDICATIONS AND USAGE To reduce the development of drug-resistant bacteria and maintain the effectiveness of XIFAXAN and other antibacterial drugs, XIFAXAN when used to treat infection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

XIFAXAN is a rifamycin antibacterial indicated for: • Treatment of travelers’ diarrhea (TD) caused by noninvasive strains of Escherichia coli in adult and pediatric patients 12 years of age and older. ( 1.1 ) • Reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults. ( 1.2 ) • Treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults.

( 1.3 ) Limitations of Use TD: Should not use in patients with diarrhea complicated by fever or blood in the stool or diarrhea due to pathogens other than Escherichia coli. ( 1.1, 5.1 )

1.1Travelers’ Diarrhea XIFAXAN is indicated for the treatment of travelers’ diarrhea (TD) caused by noninvasive strains of Escherichia coli in adults and pediatric patients 12 years of age and older. Limitations of Use XIFAXAN should not be used in patients with diarrhea complicated by fever or blood in the stool or diarrhea due to pathogens other than Escherichia coli [see Warnings and Precautions ( 5.1 ), Clinical Pharmacology ( 12.4 ), Clinical Studies ( 14.1 )].

1.2Hepatic Encephalopathy XIFAXAN is indicated for reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults. In the placebo-controlled trial of XIFAXAN for HE, 91% of the patients were using lactulose concomitantly. Differences in the treatment effect of those patients not using lactulose concomitantly could not be assessed.

XIFAXAN has not been studied in patients with MELD (Model for End-Stage Liver Disease) scores >25, and only 8.6% of patients in the placebo-controlled trial had MELD scores over 19. There is increased systemic exposure in patients with more severe hepatic dysfunction [see Warnings and Precautions ( 5.4 ), Use in Specific Populations ( 8.7 ), Clinical Pharmacology ( 12.3 )].

1.3Irritable Bowel Syndrome with Diarrhea XIFAXAN is indicated for the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults.

⏱️ Dosage and Administration 171 words ▾

2 DOSAGE AND ADMINISTRATION Condition Recommended Oral Dosage TD ( 2.1 ) 200 mg 3 times a day for 3 days HE ( 2.2 ) 550 mg 2 times a day IBS-D ( 2.3 ) 550 mg 3 times a day for 14 days. Patients who experience recurrence can be retreated up to 2 times with the same regimen. XIFAXAN can be taken with or without food. ( 2.4 )

2.1Dosage for Travelers’ Diarrhea The recommended dosage of XIFAXAN is 200 mg taken orally three times a day for 3 days.

2.2Dosage for Hepatic Encephalopathy The recommended dosage of XIFAXAN is 550 mg taken orally two times a day.

2.3Dosage for Irritable Bowel Syndrome with Diarrhea The recommended dosage of XIFAXAN is 550 mg taken orally three times a day for 14 days. Patients who experience a recurrence of symptoms can be retreated up to two times with the same dosage regimen.

2.4Administration XIFAXAN can be taken with or without food [see Clinical Pharmacology ( 12.3 )].

💊 Dosage Forms and Strengths 63 words ▾

3 DOSAGE FORMS AND STRENGTHS XIFAXAN is a pink-colored biconvex tablet and is available in the following strengths: • 200 mg – a round tablet debossed with “Sx” on one side and plain on the other. • 550 mg – an oval tablet debossed with “rfx” on one side and plain on the other. 200 mg and 550 mg tablets ( 3 )

⛔ Contraindications 60 words ▾

4 CONTRAINDICATIONS XIFAXAN is contraindicated in patients with a hypersensitivity to rifaximin, any of the rifamycin antimicrobial agents, or any of the components in XIFAXAN. Hypersensitivity reactions have included exfoliative dermatitis, angioneurotic edema, and anaphylaxis [see Adverse Reactions ( 6.2 )] . History of hypersensitivity to rifaximin, rifamycin antimicrobial agents, or any of the components of XIFAXAN. ( 4) )

⚠️ Warnings and Cautions ~3 min read ▾

5 WARNINGS AND PRECAUTIONS • Travelers’ Diarrhea Not Caused by E. coli : XIFAXAN was not effective in diarrhea complicated by fever and/or blood in the stool or diarrhea due to pathogens other than E. coli . If diarrhea symptoms get worse or persist for more than 24 to 48 hours, discontinue XIFAXAN and consider alternative antibiotics. ( 5.1 ) • Clostridium difficile -Associated Diarrhea: Evaluate if diarrhea occurs after therapy or does not improve or worsens during therapy.

( 5.2 ) • Hepatic Impairment: Use with caution in patients with severe (Child-Pugh Class C) hepatic impairment. ( 5.4 , 8.7 ) • Concomitant P-glycoprotein (P-gp) inhibitors (e.g., cyclosporine): Caution should be exercised when concomitant use of XIFAXAN and a P-glycoprotein inhibitor is needed. ( 5.5, 7.1 )

5.1Travelers’ Diarrhea Not Caused by Escherichia coli XIFAXAN was not found to be effective in patients with diarrhea complicated by fever and/or blood in the stool or diarrhea due to pathogens other than Escherichia coli. Discontinue XIFAXAN if diarrhea symptoms get worse or persist more than 24 to 48 hours and alternative antibiotic therapy should be considered. XIFAXAN is not effective in cases of travelers’ diarrhea due to Campylobacter jejuni .

The effectiveness of XIFAXAN in travelers’ diarrhea caused by Shigella spp. and Salmonella spp. has not been proven. XIFAXAN should not be used in patients where Campylobacter jejuni, Shigella spp., or Salmonella spp. may be suspected as causative pathogens [ see Indications and Usage ( 1.1 )].

5.2Clostridium difficile- Associated Diarrhea Clostridium difficile- associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including XIFAXAN, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon which may lead to overgrowth of C. difficile. C. difficile produces toxins A and B which contribute to the development of CDAD.

Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.

If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C . difficile, and surgical evaluation should be instituted as clinically indicated.

5.3Development of Drug-Resistant Bacteria Prescribing XIFAXAN for travelers’ diarrhea in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

5.4Severe (Child-Pugh Class C) Hepatic Impairment There is increased systemic exposure in patients with severe hepatic impairment. The clinical trials were limited to patients with MELD scores <25. Therefore, caution should be exercised when administering XIFAXAN to patients with severe hepatic impairment (Child-Pugh Class C) [ see Use in Specific Populations ( 8.7 ), Clinical Studies ( 14.2 )].

5.5Concomitant Use with P-glycoprotein Inhibitors Concomitant administration of drugs that are P-glycoprotein (P-gp) inhibitors with XIFAXAN can substantially increase the systemic exposure to rifaximin. Caution should be exercised when concomitant use of XIFAXAN and a P-gp inhibitor such as cyclosporine is needed. In patients with hepatic impairment, a potential additive effect of reduced metabolism and concomitant P-gp inhibitors may further increase the systemic exposure to rifaximin [see Drug Interactions ( 7.1 ), Clinical Pharmacology ( 12.3 )].

🤒 Adverse Reactions ~3 min read ▾

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in labeling: • Clostridium difficile -associated diarrhea [see Warnings and Precautions ( 5.2 )] Most common adverse reactions: • TD (≥2%): Headache ( 6.1 ) • HE (≥10%): Peripheral edema, nausea, constipation, dizziness, fatigue, urinary tract infection, insomnia, anemia, pruritus, and ascites ( 6.1 ) • IBS-D (≥2%): ALT increased, nausea ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Salix Pharmaceuticals at 1-800-321-4576 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

6.1Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Travelers’ Diarrhea The safety of XIFAXAN 200 mg taken three times a day was evaluated in patients with travelers’ diarrhea consisting of 320 patients in two placebo-controlled clinical trials with 95% of patients receiving three or four days of treatment with XIFAXAN.

The population studied had a mean age of 31.3 (18-79) years of which approximately 3% were ≥65 years old, 53% were male and 84% were White, 11% were Hispanic. Discontinuations due to adverse reactions occurred in 0.4% of patients. The adverse reactions leading to discontinuation were taste loss, dysentery, weight decrease, anorexia, nausea and nasal passage irritation.

The adverse reaction that occurred at a frequency ≥2% in XIFAXAN-treated patients (n=320) at a higher rate than placebo (n=228) in the two placebo-controlled trials of TD was: • headache (10% XIFAXAN, 9% placebo) Hepatic Encephalopathy Trial 1 The data described in Table 1 reflect exposure to XIFAXAN in 348 patients, including 265 exposed for 6 months and 202 exposed for more than a year (mean exposure was 364 days). The safety of XIFAXAN 550 mg taken two times a day for reducing the risk of overt HE recurrence in adult patients was evaluated in a 6-month placebo-controlled clinical trial (n=140) and in a long-term follow-up study (n=280) [see Clinical Studies ( 14.2 )] .

The population studied had a mean age of 56 (range: 21 to 82) years; approximately 20% of the patients were ≥65 years old, 61% were male, 86% were White, and 4% were Black. Ninety-one percent of patients in the trial were taking lactulose concomitantly. The most common adverse reactions that occurred at an incidence ≥5% and at a higher incidence in XIFAXAN-treated subjects than in the placebo group in the 6-month trial are provided in Table 1.

Table 1: Common Adverse Reactions*from a Clinical Study of XIFAXAN in Adult Patients with Hepatic Encephalopathy (Trial 1) Adverse Reaction XIFAXAN Tablets 550 mg TWICE DAILY (N=140) n (%) Placebo (N=159) n (%) Peripheral edema 21 (15%) 13 (8%) Nausea 20 (14%) 21 (13%) Dizziness 18 (13%) 13 (8%) Fatigue 17 (12%) 18 (11%) Ascites 16 (11%) 15 (9%) Muscle spasms 13 (9%) 11 (7%) Pruritus 13 (9%) 10 (6%) Abdominal pain 12 (9%) 13 (8%) Anemia 11 (8%) 6 (4%) Depression 10 (7%) 8 (5%) Nasopharyngitis 10 (7%) 10 (6%) Abdominal pain upper 9 (6%) 8 (5%) Arthralgia 9 (6%) 4 (3%) Dyspnea 9 (6%) 7 (4%) Pyrexia 9 (6%) 5 (3%) Rash 7 (5%) 1.

(4%) *Adverse reactions that occurred in ≥5% of XIFAXAN-treated patients and greater than in patients who received placebo Trial 2 The data described in Table 2 reflect exposure to XIFAXAN in 221 of 222 randomized subjects, exposed for a median duration of 169 days, with 113 exposed to XIFAXAN monotherapy and 108 exposed to XIFAXAN added onto lactulose in a six-month active-controlled trial [see Clinical Studies ( 14.2 )]. The population studied had a mean age of 58; approximately 63% of subjects were male. The most common adverse reactions that occurred at an incidence ≥5% are provided in Table 2.

Table 2: Common Adverse Reactions*from a Clinical Study of XIFAXAN + Lactulose Compared to XIFAXAN Monotherapy… [Excerpted — this section continues on DailyMed.]

🔄 Drug Interactions 203 words ▾

7 DRUG INTERACTIONS Warfarin: Monitor INR and prothrombin time; dose adjustment of warfarin may be needed to maintain target INR range. ( 7.2 )

7.1P-glycoprotein Inhibitors Concomitant administration of cyclosporine, an inhibitor of P-gp and OATPs significantly increased the systemic exposure of rifaximin. In patients with hepatic impairment, a potential additive effect of reduced metabolism and concomitant P-gp inhibitors may further increase the systemic exposure to rifaximin. Caution should be exercised when concomitant use of XIFAXAN and a P-gp inhibitor such as cyclosporine is needed [see Warnings and Precautions ( 5.5 ), Clinical Pharmacology ( 12.3 )].

7.2Warfarin Changes in INR have been reported postmarketing in patients receiving rifaximin and warfarin concomitantly. Monitor INR and prothrombin time. Dose adjustment of warfarin may be needed to maintain target INR range. See prescribing information for warfarin.

7.3CYP3A4 Substrates An in vitro study has suggested that rifaximin induces CYP3A4 [see Clinical Pharmacology ( 12.3 )] . However, in patients with normal liver function, XIFAXAN at the recommended dosing regimen is not expected to induce CYP3A4. It is unknown whether rifaximin can have a significant effect on the pharmacokinetics of concomitant CYP3A4 substrates in patients with reduced liver function who have elevated rifaximin concentrations.

👥 Use in Specific Populations ~3 min read ▾

8 USE IN SPECIFIC POPULATIONS Pregnancy: May cause fetal harm ( 8.1 )

8.1Pregnancy Risk Summary There are no available data on XIFAXAN use in pregnant women to inform any drug-associated risks. Teratogenic effects were observed in animal reproduction studies following administration of rifaximin to pregnant rats and rabbits during organogenesis at doses approximately 0.9 to 5 times and 0.7 to 33 times, respectively of the recommended human doses of 600 mg to 1,650 mg per day. In rabbits, ocular, oral and maxillofacial, cardiac, and lumbar spine malformations were observed.

Ocular malformations were observed in both rats and rabbits at doses that caused reduced maternal body weight gain [see Data] . In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Advise pregnant women of the potential risk to a fetus.

Data Animal Data Rifaximin was teratogenic in rats at doses of 150 to 300 mg/kg (approximately 2.5 to 5 times the recommended dose for TD [600 mg per day], and approximately 1.3 to 2.6 times the recommended dose for HE [1,100 mg per day], and approximately 0.9 to 1.8 times the recommended dose for IBS-D [1,650 mg per day] adjusted for body surface area). Rifaximin was teratogenic in rabbits at doses of 62.5 to 1,000 mg/kg (approximately 2 to 33 times the recommended dose for TD [600 mg per day], and approximately 1.1 to 18 times the recommended dose for HE [1,100 mg per day], and approximately 0.7 to 12 times the recommended dose for IBS-D [1,650 mg per day] adjusted for body surface area).

These effects include cleft palate, agnathia, jaw shortening, hemorrhage, eye partially open, small eyes, brachygnathia, incomplete ossification, and increased thoracolumbar vertebrae. A pre and postnatal development study in rats showed no evidence of any adverse effect on pre and postnatal development at oral doses of rifaximin up to 300 mg/kg per day (approximately 5 times the recommended dose for TD [600 mg per day], and approximately 2.6 times the recommended dose for HE [1,100 mg per day], and approximately 1.8 times the recommended dose for IBS-D [1,650 mg per day] adjusted for body surface area).

8.2Lactation Risk Summary There is no information regarding the presence of rifaximin in human milk, the effects of rifaximin on the breastfed infant, or the effects of rifaximin on milk production. The development and health benefits of breastfeeding should be considered along with the mother’s clinical need for XIFAXAN and any potential adverse effects on the breastfed infant from XIFAXAN or from the underlying maternal condition.

8.4Pediatric Use The safety and effectiveness of XIFAXAN has not been established in pediatric patients less than 12 years of age with TD or in patients less than 18 years of age for HE and IBS-D.

8.5Geriatric Use Of the total number of patients in the clinical study of XIFAXAN for HE, 19% of patients were 65 and over, while 2% were 75 and over. In the clinical studies of IBS-D, 11% of patients were 65 and over, while 2% were 75 and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects for either indication.

Clinical studies with XIFAXAN for TD did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently than younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

8.6Renal Impairment The pharmacokinetics of rifaximin in patients with impaired renal function has not been studied.

8.7Hepatic Impairment Following administration of XIFAXAN 550 mg twice daily to patients with a history of hepatic encephalopathy, the systemic exposure (i.e., AUC τ ) of rifaximin was about 10-, 14-, and 21-fold higher in those patients with mild (C… [Excerpted — this section continues on DailyMed.]

🤰 Pregnancy ~2 min read ▾

8.1Pregnancy Risk Summary There are no available data on XIFAXAN use in pregnant women to inform any drug-associated risks. Teratogenic effects were observed in animal reproduction studies following administration of rifaximin to pregnant rats and rabbits during organogenesis at doses approximately 0.9 to 5 times and 0.7 to 33 times, respectively of the recommended human doses of 600 mg to 1,650 mg per day. In rabbits, ocular, oral and maxillofacial, cardiac, and lumbar spine malformations were observed.

Ocular malformations were observed in both rats and rabbits at doses that caused reduced maternal body weight gain [see Data] . In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Advise pregnant women of the potential risk to a fetus.

Data Animal Data Rifaximin was teratogenic in rats at doses of 150 to 300 mg/kg (approximately 2.5 to 5 times the recommended dose for TD [600 mg per day], and approximately 1.3 to 2.6 times the recommended dose for HE [1,100 mg per day], and approximately 0.9 to 1.8 times the recommended dose for IBS-D [1,650 mg per day] adjusted for body surface area). Rifaximin was teratogenic in rabbits at doses of 62.5 to 1,000 mg/kg (approximately 2 to 33 times the recommended dose for TD [600 mg per day], and approximately 1.1 to 18 times the recommended dose for HE [1,100 mg per day], and approximately 0.7 to 12 times the recommended dose for IBS-D [1,650 mg per day] adjusted for body surface area).

These effects include cleft palate, agnathia, jaw shortening, hemorrhage, eye partially open, small eyes, brachygnathia, incomplete ossification, and increased thoracolumbar vertebrae. A pre and postnatal development study in rats showed no evidence of any adverse effect on pre and postnatal development at oral doses of rifaximin up to 300 mg/kg per day (approximately 5 times the recommended dose for TD [600 mg per day], and approximately 2.6 times the recommended dose for HE [1,100 mg per day], and approximately 1.8 times the recommended dose for IBS-D [1,650 mg per day] adjusted for body surface area).

🧒 Pediatric Use 37 words ▾

8.4Pediatric Use The safety and effectiveness of XIFAXAN has not been established in pediatric patients less than 12 years of age with TD or in patients less than 18 years of age for HE and IBS-D.

🧓 Geriatric Use 120 words ▾

8.5Geriatric Use Of the total number of patients in the clinical study of XIFAXAN for HE, 19% of patients were 65 and over, while 2% were 75 and over. In the clinical studies of IBS-D, 11% of patients were 65 and over, while 2% were 75 and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects for either indication.

Clinical studies with XIFAXAN for TD did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently than younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

🆘 Overdosage 80 words ▾

10 OVERDOSAGE No specific information is available on the treatment of overdosage with XIFAXAN. In clinical studies at doses higher than the recommended dose (greater than 600 mg per day for TD, greater than 1,100 mg per day for HE or greater than 1,650 mg per day for IBS-D), adverse reactions were similar in subjects who received doses higher than the recommended dose and placebo. In the case of overdosage, discontinue XIFAXAN, treat symptomatically, and institute supportive measures as required.

🧬 Clinical Pharmacology ~3 min read ▾

12 CLINICAL PHARMACOLOGY

12.1Mechanism of Action Rifaximin is an antibacterial drug [see Clinical Pharmacology ( 12.4 )].

12.3Pharmacokinetics Absorption In healthy subjects, the mean time to reach peak rifaximin plasma concentrations was about an hour and the mean Cmax ranged 2.4 to 4 ng/mL after a single dose and multiple doses of XIFAXAN 550 mg. Travelers’ Diarrhea Systemic absorption of XIFAXAN (200 mg three times daily) was evaluated in 13 subjects challenged with shigellosis on Days 1 and 3 of a three-day course of treatment. Rifaximin plasma concentrations and exposures were low and variable.

There was no evidence of accumulation of rifaximin following repeated administration for 3 days (9 doses). Peak plasma rifaximin concentrations after 3 and 9 consecutive doses ranged from 0.81 to 3.4 ng/mL on Day 1 and 0.68 to 2.26 ng/mL on Day 3. Similarly, AUC0-last estimates were 6.95 ± 5.15 ng•h/mL on Day 1 and 7.83 ± 4.94 ng•h/mL on Day 3.

XIFAXAN is not suitable for treating systemic bacterial infections because of limited systemic exposure after oral administration [see Warnings and Precautions ( 5.1 )] . Hepatic Encephalopathy Mean rifaximin exposure (AUCτ) in patients with a history of HE was approximately 12-fold higher than that observed in healthy subjects. Among patients with a history of HE, the mean AUC in patients with Child-Pugh Class C hepatic impairment was 2-fold higher than in patients with Child-Pugh Class A hepatic impairment [see Warnings and Precautions ( 5.4 ), Use in Specific Populations (8.7 )].

Irritable Bowel Syndrome with Diarrhea In patients with irritable bowel syndrome with diarrhea (IBS-D) treated with XIFAXAN 550 mg three times a day for 14 days, the median Tmax was 1 hour and mean Cmax and AUC were generally comparable with those in healthy subjects. After multiple doses, AUCtau was 1.65-fold higher than that on Day 1 in IBS-D patients (see Table 3). Table 1.

Mean (± SD) Pharmacokinetic Parameters of Rifaximin Following XIFAXAN 550 mg Three Times a Day in IBS-D Patients and Healthy Subjects Healthy Subjects IBS-D Patients Single- Dose (Day 1) n=12 Multiple- Dose (Day 14) n=14 Single- Dose (Day 1) n=24 Multiple- Dose (Day 14) n=24 C max (ng/mL) 4.04 (1.51) 2.39 (1.28) 3.49 (1.36) 4.22 (2.66) T max (h)ª 0.75 (0.5-2.1) 1.00 (0.5-2.0) 0.78 (0-2) 1.00 (0.5-2) AUC tau (ng•h/mL) 10.4 (3.47) 9.30 (2.7) 9.69 (4.16) 16.0 (9.59) Half-life (h) 1.83 (1.38) 5.63 (5.27) 3.14 (1.71) 6.08 (1.68) ª Median (range) Food Effect in Healthy Subjects A high-fat meal consumed 30 minutes prior to XIFAXAN dosing in healthy subjects delayed the mean time to peak plasma concentration from 0.75 to 1.5 hours and increased the systemic exposure (AUC) of rifaximin by 2-fold but did not significantly affect C max .

Dose-Proportionality After oral administration of XIFAXAN 200 mg, 400 mg, or 600 mg, rifaximin systemic exposures increased dose- dependently by approximately 2-fold for both AUClast and Cmax from 200 mg to 400 mg, but with a less than dose- proportional increase of 1.3-fold for both AUClast and Cmax from 400 mg to 600 mg administration. Distribution Rifaximin is moderately bound to human plasma proteins. In vivo , the mean protein binding ratio was 67.5% in healthy subjects and 62% in patients with hepatic impairment when XIFAXAN was administered.

Elimination The mean half-life of rifaximin in healthy subjects at steady-state was 5.6 hours and was 6 hours in IBS-D patients. Metabolism In an in vitro study, rifaximin was metabolized mainly by CYP3A4. Rifaximin accounted for 18% of radioactivity in plasma suggesting that the absorbed rifaximin undergoes extensive metabolism.

Excretion In a mass balance study, after administration of 400 mg 14 C-rifaximin orally to healthy volunteers, of the 96.94% total recovery, 96.62% of the administered radioactivity was recovered in feces mostly as the unchanged drug and 0.32% was recovered in urine mostly as metabolites with 0.03% as the unchanged drug. Biliary excretion of rifa… [Excerpted — this section continues on DailyMed.]

🧬 Mechanism of Action 15 words ▾

12.1Mechanism of Action Rifaximin is an antibacterial drug [see Clinical Pharmacology ( 12.4 )].

📦 How Supplied / Storage and Handling 65 words ▾

16 HOW SUPPLIED/STORAGE AND HANDLING The 550 mg tablet is a pink-colored, oval, biconvex tablet with “rfx” debossed on one side and plain on the other. It is available in the following presentations: Bottles of approximately 360 tablets, NDC 55154-6777-8 Storage Store XIFAXAN Tablets at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature].

📋 Description 146 words ▾

11 DESCRIPTION XIFAXAN tablets contain rifaximin, a non-aminoglycoside semi-synthetic, nonsystemic antibiotic derived from rifamycin SV. Rifaximin is a structural analog of rifampin. The chemical name for rifaximin is (2 S ,16 Z ,18 E ,20 S ,21 S ,22 R ,23 R ,24 R ,25 S ,26 S ,27 S ,28 E )-5,6,21,23,25-pentahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca-[1,11,13]trienimino)benzofuro[4,5-e]pyrido[1,2-á]-benzimidazole-1,15(2 H )-dione,25- acetate.

The empirical formula is C43H51N3O11 and its molecular weight is 785.9. The chemical structure is represented below: XIFAXAN tablets for oral administration are film-coated and contain 200 mg or 550 mg of rifaximin. Inactive ingredients: Each 200 mg tablet contains colloidal silicon dioxide, disodium edetate, glycerol palmitostearate, hypromellose, microcrystalline cellulose, propylene glycol, red iron oxide, sodium starch glycolate, talc, and titanium dioxide.

Each 550 mg tablet contains colloidal silicon dioxide, glycerol palmitostearate, microcrystalline cellulose, polyethylene glycol/macrogol, polyvinyl alcohol, red iron oxide, sodium starch glycolate, talc, and titanium dioxide. chem structure

💬 Information for Patients ~2 min read ▾

17 PATIENT COUNSELING INFORMATION Persistent Diarrhea For those patients being treated for travelers’ diarrhea, discontinue XIFAXAN if diarrhea persists more than 24-48 hours or worsens. Advise the patient to seek medical care for fever and/or blood in the stool [see Warnings and Precautions ( 5.1 )]. Clostridium difficile- Associated Diarrhea Clostridium difficile -associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including XIFAXAN, and may range in severity from mild diarrhea to fatal colitis.

Treatment with antibiotics alters the normal flora of the colon which may lead to C. difficile . Patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If diarrhea occurs after therapy or does not improve or worsens during therapy, advise patients to contact a physician as soon as possible [see Warnings and Precautions ( 5.2 )].

Administration with Food Inform patients that XIFAXAN may be taken with or without food. Antibacterial Resistance Counsel patients that antibacterial drugs including XIFAXAN should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold).

When XIFAXAN is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by XIFAXAN or other antibacterial drugs in the future [see Warnings and Precautions ( 5.3 )]. Distributed by: Salix Pharmaceuticals, a division of Bausch Health US, LLC Bridgewater, NJ 08807 USA Patented.

See https://patents.salix.com for US patent information. The XIFAXAN 200 mg and 550 mg products and the XIFAXAN trademark are licensed by Alfasigma S.p.A. to Salix Pharmaceuticals or its affiliates. All other product/brand names are trademarks of the respective owners. © 2023 Salix Pharmaceuticals, Inc. or its affiliates Website: www.Salix.com Distributed By: Cardinal Health Dublin, OH 43017 ER7970I Rev.

B 9693505-70016243-02 (insert) 9693605-70016244-02 (topsert)

🧬 Pharmacokinetics ~3 min read ▾

12.3Pharmacokinetics Absorption In healthy subjects, the mean time to reach peak rifaximin plasma concentrations was about an hour and the mean Cmax ranged 2.4 to 4 ng/mL after a single dose and multiple doses of XIFAXAN 550 mg. Travelers’ Diarrhea Systemic absorption of XIFAXAN (200 mg three times daily) was evaluated in 13 subjects challenged with shigellosis on Days 1 and 3 of a three-day course of treatment. Rifaximin plasma concentrations and exposures were low and variable.

There was no evidence of accumulation of rifaximin following repeated administration for 3 days (9 doses). Peak plasma rifaximin concentrations after 3 and 9 consecutive doses ranged from 0.81 to 3.4 ng/mL on Day 1 and 0.68 to 2.26 ng/mL on Day 3. Similarly, AUC0-last estimates were 6.95 ± 5.15 ng•h/mL on Day 1 and 7.83 ± 4.94 ng•h/mL on Day 3.

XIFAXAN is not suitable for treating systemic bacterial infections because of limited systemic exposure after oral administration [see Warnings and Precautions ( 5.1 )] . Hepatic Encephalopathy Mean rifaximin exposure (AUCτ) in patients with a history of HE was approximately 12-fold higher than that observed in healthy subjects. Among patients with a history of HE, the mean AUC in patients with Child-Pugh Class C hepatic impairment was 2-fold higher than in patients with Child-Pugh Class A hepatic impairment [see Warnings and Precautions ( 5.4 ), Use in Specific Populations (8.7 )].

Irritable Bowel Syndrome with Diarrhea In patients with irritable bowel syndrome with diarrhea (IBS-D) treated with XIFAXAN 550 mg three times a day for 14 days, the median Tmax was 1 hour and mean Cmax and AUC were generally comparable with those in healthy subjects. After multiple doses, AUCtau was 1.65-fold higher than that on Day 1 in IBS-D patients (see Table 3). Table 1.

Mean (± SD) Pharmacokinetic Parameters of Rifaximin Following XIFAXAN 550 mg Three Times a Day in IBS-D Patients and Healthy Subjects Healthy Subjects IBS-D Patients Single- Dose (Day 1) n=12 Multiple- Dose (Day 14) n=14 Single- Dose (Day 1) n=24 Multiple- Dose (Day 14) n=24 C max (ng/mL) 4.04 (1.51) 2.39 (1.28) 3.49 (1.36) 4.22 (2.66) T max (h)ª 0.75 (0.5-2.1) 1.00 (0.5-2.0) 0.78 (0-2) 1.00 (0.5-2) AUC tau (ng•h/mL) 10.4 (3.47) 9.30 (2.7) 9.69 (4.16) 16.0 (9.59) Half-life (h) 1.83 (1.38) 5.63 (5.27) 3.14 (1.71) 6.08 (1.68) ª Median (range) Food Effect in Healthy Subjects A high-fat meal consumed 30 minutes prior to XIFAXAN dosing in healthy subjects delayed the mean time to peak plasma concentration from 0.75 to 1.5 hours and increased the systemic exposure (AUC) of rifaximin by 2-fold but did not significantly affect C max .

Dose-Proportionality After oral administration of XIFAXAN 200 mg, 400 mg, or 600 mg, rifaximin systemic exposures increased dose- dependently by approximately 2-fold for both AUClast and Cmax from 200 mg to 400 mg, but with a less than dose- proportional increase of 1.3-fold for both AUClast and Cmax from 400 mg to 600 mg administration. Distribution Rifaximin is moderately bound to human plasma proteins. In vivo , the mean protein binding ratio was 67.5% in healthy subjects and 62% in patients with hepatic impairment when XIFAXAN was administered.

Elimination The mean half-life of rifaximin in healthy subjects at steady-state was 5.6 hours and was 6 hours in IBS-D patients. Metabolism In an in vitro study, rifaximin was metabolized mainly by CYP3A4. Rifaximin accounted for 18% of radioactivity in plasma suggesting that the absorbed rifaximin undergoes extensive metabolism.

Excretion In a mass balance study, after administration of 400 mg 14 C-rifaximin orally to healthy volunteers, of the 96.94% total recovery, 96.62% of the administered radioactivity was recovered in feces mostly as the unchanged drug and 0.32% was recovered in urine mostly as metabolites with 0.03% as the unchanged drug. Biliary excretion of rifaximin was suggested by a separate study in which rifaximin was detected in the bile after cholecystectomy in patients with… [Excerpted — this section continues on DailyMed.]

🔬 Clinical Studies ~3 min read ▾

14 CLINICAL STUDIES

14.1Travelers’ Diarrhea The efficacy of XIFAXAN given as 200 mg orally taken three times a day for 3 days was evaluated in 2 randomized, multi‑center, double-blind, placebo-controlled studies in adult subjects with travelers’ diarrhea. One study was conducted at clinical sites in Mexico, Guatemala, and Kenya (Study 1). The other study was conducted in Mexico, Guatemala, Peru, and India (Study 2).

Stool specimens were collected before treatment and 1 to 3 days following the end of treatment to identify enteric pathogens. The predominant pathogen in both studies was Escherichia coli . The clinical efficacy of XIFAXAN was assessed by the time to return to normal, formed stools, and resolution of symptoms.

The primary efficacy endpoint was time to last unformed stool (TLUS) which was defined as the time to the last unformed stool passed, after which clinical cure was declared. Table 5 displays the median TLUS and the number of patients who achieved clinical cure for the intent to treat (ITT) population of Study 1. The duration of diarrhea was significantly shorter in patients treated with XIFAXAN than in the placebo group.

More patients treated with XIFAXAN were classified as clinical cures than were those in the placebo group. Table 3. Clinical Response in Study 1 (ITT population) XIFAXAN (n=125) Placebo (n=129) Estimate (97.5% CI) Median TLUS (hours) 32.5 58.6 2 Hazard Ratio (p-value <0.001) (1.26, 2.50) Clinical cure, n (%) 99 (79) 78 (60) 19 Difference in rates (p-value <0.01) (5.3, 32.1) Microbiological eradication (defined as the absence of a baseline pathogen in culture of stool after 72 hours of therapy) rates for Study 1 are presented in Table 6 for patients with any pathogen at baseline and for the subset of patients with Escherichia coli at baseline.

Escherichia coli was the only pathogen with sufficient numbers to allow comparisons between treatment groups. Even though XIFAXAN had microbiologic activity similar to placebo, it demonstrated a clinically significant reduction in duration of diarrhea and a higher clinical cure rate than placebo. Therefore, patients should be managed based on clinical response to therapy rather than microbiologic response.

Table 4. Microbiologic Eradication Rates in Study 1 Subjects with a Baseline Pathogen XIFAXAN Placebo Overall 48/70 (69) 41/61 (67) E. coli 38/53 (72) 40/54 (74) The results of Study 2 supported the results presented for Study 1. In addition, this study provided evidence that subjects treated with XIFAXAN with fever and/or blood in the stool at baseline had prolonged TLUS.

These subjects had lower clinical cure rates than those without fever or blood in the stool at baseline. Many of the patients with fever and/or blood in the stool (dysentery-like diarrheal syndromes) had invasive pathogens, primarily Campylobacter jejuni , isolated in the baseline stool. Also in this study, the majority of the subjects treated with XIFAXAN who had Campylobacter jejuni isolated as a sole pathogen at baseline failed treatment and the resulting clinical cure rate for these patients was 23.5% (4/17).

In addition to not being different from placebo, the microbiologic eradication rates for subjects with Campylobacter jejuni isolated at baseline were much lower than the eradication rates seen for Escherichia coli . In an unrelated open-label, pharmacokinetic study of oral XIFAXAN 200 mg taken every 8 hours for 3 days, 15 adult subjects were challenged with Shigella flexneri 2a, of whom 13 developed diarrhea or dysentery and were treated with XIFAXAN. Although this open-label challenge trial was not adequate to assess the effectiveness of XIFAXAN in the treatment of shigellosis, the following observations were noted: eight subjects received rescue treatment with ciprofloxacin either because of lack of response to XIFAXAN treatment within 24 hours (2), or because they developed severe dysentery (5), or because of recurrence of Shigella flexneri 2a in the stool (1); five of t… [Excerpted — this section continues on DailyMed.]

🧪 Nonclinical Toxicology 220 words ▾

13 NONCLINICAL TOXICOLOGY

13.1Carcinogenesis, Mutagenesis, Impairment of Fertility Malignant schwannomas in the heart were significantly increased in male Crl: CD (SD) rats that received rifaximin by oral gavage for two years at 150 to 250 mg/kg per day (doses equivalent to 2.4 to 4 times the recommended dose of 200 mg three times daily for TD, and equivalent to 1.3 to 2.2 times the recommended dose of 550 mg twice daily for HE, based on relative body surface area comparisons). There was no increase in tumors in Tg.rasH2 mice dosed orally with rifaximin for 26 weeks at 150 to 2,000 mg/kg per day (doses equivalent to 1.2 to 16 times the recommended daily dose for TD and equivalent to 0.7 to 9 times the recommended daily dose for HE, based on relative body surface area comparisons).

Rifaximin was not genotoxic in the bacterial reverse mutation assay, chromosomal aberration assay, rat bone marrow micronucleus assay, rat hepatocyte unscheduled DNA synthesis assay, or the CHO/HGPRT mutation assay. There was no effect on fertility in male or female rats following the administration of rifaximin at doses up to 300 mg/kg (approximately 5 times the clinical dose of 600 mg per day for TD, and approximately 2.6 times the clinical dose of 1,100 mg per day for HE, adjusted for body surface area).

📄 Carcinogenesis, Mutagenesis, Impairment of Fertility 217 words ▾

13.1Carcinogenesis, Mutagenesis, Impairment of Fertility Malignant schwannomas in the heart were significantly increased in male Crl: CD (SD) rats that received rifaximin by oral gavage for two years at 150 to 250 mg/kg per day (doses equivalent to 2.4 to 4 times the recommended dose of 200 mg three times daily for TD, and equivalent to 1.3 to 2.2 times the recommended dose of 550 mg twice daily for HE, based on relative body surface area comparisons). There was no increase in tumors in Tg.rasH2 mice dosed orally with rifaximin for 26 weeks at 150 to 2,000 mg/kg per day (doses equivalent to 1.2 to 16 times the recommended daily dose for TD and equivalent to 0.7 to 9 times the recommended daily dose for HE, based on relative body surface area comparisons).

Rifaximin was not genotoxic in the bacterial reverse mutation assay, chromosomal aberration assay, rat bone marrow micronucleus assay, rat hepatocyte unscheduled DNA synthesis assay, or the CHO/HGPRT mutation assay. There was no effect on fertility in male or female rats following the administration of rifaximin at doses up to 300 mg/kg (approximately 5 times the clinical dose of 600 mg per day for TD, and approximately 2.6 times the clinical dose of 1,100 mg per day for HE, adjusted for body surface area).

📄 Package Label / Principal Display Panel 43 words ▾

Package/Label Display Panel Contains Approximately 360 Tablets XIFAXAN® (rifaximin) tablets 550 mg Each tablet contains: 550 mg of rifaximin. Pharmacist: Dispense in a tight multiple- unit container as defined in USP. Rx Only WARNING: Keep out of reach of children. 550mg bottle label

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗

Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Xifaxan — the program that covers self-administered drugs. 1 manufacturer.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Xifaxan. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$338.26M
Claims incl. refills
111.6K
Beneficiaries
53.8K
Spend / beneficiary
$6,283.19
Spend / claim
$3,030.69
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.

Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for XIFAXAN (this brand).

Top reported reactions

Death4,162
Hospitalisation1,866
Diarrhoea1,243
Therapy Interrupted1,119
Ammonia Increased852
Nausea837
Hepatic Encephalopathy809

Age at onset

Neonate3
Infant6
Child28
Adolescent23
Adult1,494
Elderly947

Reporter sex

20,826 reports
Male · 48%
Female · 52%
Unknown · 0%

Serious outcomes

Hospitalization8,176
Death6,105
Life-threatening478
Disabling287
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 1,958 0
Most recent year is provisional (FAERS lags ~3 months).
Where does this data come from?
Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

About this NDC listing & data coverage

Finished prescription product
What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos ✓ Available
Inactive ingredients (structured) ✓ Available
NADAC pharmacy acquisition price (CMS) — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey.
Orange Book / therapeutic-equivalence data ✓ Available
HCPCS J-code billing crosswalk — Not published for this NDC Most self-administered / retail products have no J-code — that is normal.
Medicaid utilization (CMS SDUD) — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The form printed on the packaging and shown on DailyMed is the one the FDA registered. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero and the dashes are dropped. The Identity section at the top of this page lists each form of this code.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Cardinal Health 107, LLC. Listing status can change — the directory data on this page refreshes weekly.
Who lists this product with the FDA?
Cardinal Health 107, LLC is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.
← 55154-6754-00 · Cardinal 55154-6818-00 · Cardinal →
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.