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Relistor Methylnaltrexone bromide 150 mg Tablet, 6-count — NDC 65649-0150-06 package photo

Relistor Methylnaltrexone bromide 150 mg Tablet, 6-count

by Salix Pharmaceuticals, Inc. · 1 BOTTLE in 1 CARTON (65649-150-06) / 6 TABLET in 1 BOTTLE
NDC 65649-0150-06
🏷️ FDA NDC (as labeled) 65649-150-06 billing pads the product segment with a zero
This package
Contains6-count Pack sizes2 compare ↓
Also priced by: Part D plans $326.40/unit — full pricing hub ↓
Also comes in: 90 tablets 65649-0150-90
Rx only Brand On market Non-controlled
🗂️ Data synced 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

🆔 Identity & classification

FDA NDC (as labeled) 65649-150-06
Product NDC 65649-150
11-digit billing NDC 65649015006
RxCUI 979113, 979115, 1244060, 1244062, 1244063, 1244064, 1801514, 1801519
UNII RFO6IL3D3M
Application # NDA208271
SPL Set ID c488fb7c-0a5b-487c-b452-996809d1cb99
Established class (EPC) Opioid Antagonist
Mechanism of action Opioid Antagonists
Chemical class Quaternary Ammonium Compounds
DEA schedule Non-controlled
Marketing category NDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2008-08-01
Route ORAL
Dosage form TABLET
Substance METHYLNALTREXONE BROMIDE
GPI-14 52580050100320
GPI class Relistor
GCN Seq No 076398
GCN 41923
HICL code 035611
Ingredient (HICL) Methylnaltrexone Bromide
HIC1 code H
Therapeutic class — broad (HIC1) Nervous System (Except Autonomic)
HIC2 code H3
Therapeutic class — intermediate (HIC2) Analgesics
HIC3 code H3Y
Therapeutic class — specific (HIC3) Mu-Opioid Receptor Antagonists,Peripherally-Acting
AHFS code 56:18.04.00
AHFS class Opioid Antagonists (56:18)
FDB label name RELISTOR 150 MG TABLET
FDB brand name Relistor
Legend status F — Federal legend — prescription drug or device
Why two NDCs? The FDA registers this code as 65649-150-06 — a 5-3-2 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 product segment → 65649-0150-06. 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 Opioid Antagonist class.

Pharmacologic class Opioid Antagonist
Drug family (ATC) Peripheral opioid receptor antagonists
How it works Opioid Antagonists
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.

🏭 Manufacturer & labeler

LabelerSalix Pharmaceuticals, Inc.
Application holderSALIX PHARMACEUTICALS INC
FDA applicationNDA208271 (NDA)
Labeler code65649
First marketedAug 2008
Product typeHuman Prescription Drug
Portfolio8 products on file
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.

🩺 Clinical

Label name RELISTOR 150 MG TABLET Ingredient Methylnaltrexone Bromide
📖 What it is MedlinePlus · NLM

Methylnaltrexone is used to treat constipation caused by opioid (narcotic) pain medications in people with chronic (ongoing) pain that is not caused by cancer but may be related to a previous cancer or cancer treatment. Methylnaltrexone is in a class of medications called peripherally acting mu-opioid receptor antagonists. It works by protecting the bowel from the effects of opioid (narcotic) medications.

Read the full MedlinePlus article ↗
📗 Our plain-language guide HelloPharmacist
  • No — that's actually the key feature of this medicine. Relistor is designed to work only in your gut, not in your brain. It blocks opioid receptors in the digestive tract to reliev...
  • Will Relistor injection reduce the effectiveness of my pain medication?
  • Relistor is absorbed into your system quite quickly after a subcutaneous injection — it reaches peak levels in your blood within about 15 to 30 minutes. Many people find they need...
  • How soon after the injection should I expect results?
📖 Read our full Methylnaltrexone Injection guide →

Supplement & herbal interactions

🌿 Drug–supplement interaction checker →
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.

💊 What it looks like

Color white
ShapeRound
ImprintREL;PLAIN
Size6 mm
ScoringScored — splits in 2
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.

A current SPL was checked, but it does not contain a structured or narrative inactive-ingredient list for this product. This does not mean the product has no inactive ingredients.
Where does this data come from?
Source: official FDA Structured Product Labeling (SPL) via DailyMed and the openFDA label index. Structured IACT rows and label-wide narrative are kept separate; availability and product-level specificity depend on the submitted label.

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.

💲 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 $326.40 $1,958.38 / 6 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.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Relistor 150 mgthis 65649-0150-06 Salix 6 tablets — — FDA listed —
About this product: this is the brand-name version. We did not find an FDA-approved generic match for this exact strength, form and route.
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

🏛️
2016
First FDA approval
Jul 2016
📍
2026
Currently FDA-listed
10 years listed
🛡️
2031
Latest patent/protection listed
not a guaranteed launch date
🔒No FDA-approved generic found

We did not find an FDA-approved generic match for this exact strength, form and route. Patent/protection dates below may affect future generic timing.

🛡️ Latest patent/protection date listed: FDA patent/protection data lists protections through Mar 2031. This may affect when a full generic version becomes widely available, but it is not a guaranteed launch date.
📅 FDA approved Jul 19, 2016 RLD RS ⏳ ~4.5 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 9180125 — method of use (U-1185)
US 9492445 — method of use (U-1185)
US 9724343 — method of use (U-1185)
US 8420663 — method of use (U-1185)
US 8956651 — drug product
US 9314461 — drug product
US 10376505 — drug product
US 8524276 — drug product
US 10307417 — drug product
2016 2018 2020 2022 2024 2026 2028 2030
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 (9)
PatentTypeUse codeExpires
US 9180125 ↗ Method of use U-1185 Sep 30, 2029
US 9492445 ↗ Method of use U-1185 Sep 30, 2029
US 9724343 ↗ Method of use U-1185 Sep 30, 2029
US 8420663 ↗ Method of use U-1185 Sep 30, 2029
US 8956651 ↗ Drug product — Mar 10, 2031
US 9314461 ↗ Drug product — Mar 10, 2031
US 10376505 ↗ Drug product — Mar 10, 2031
US 8524276 ↗ Drug product — Mar 10, 2031
US 10307417 ↗ Drug product — Mar 10, 2031
Common questions
Is there a generic version of RELISTOR 150 MG TABLET?
No FDA-approved generic equivalent is currently listed in the FDA Orange Book for RELISTOR 150 MG TABLET. Based on the patents and exclusivity currently listed, the Orange Book estimate is that full-label generic entry may be delayed until Mar 2031 — an estimate, not a guaranteed launch date.
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.

💊 Medicaid utilization by pack size

Medicaid (SDUD) totals over the four most recent reported quarters for every package size of this drug — handy when a specific package (e.g. a starter/titration pack) carries little or no Medicaid volume on its own.
90 tablets65649-0150-90 17,607 Rx · $40,263,521
6 tablets this page65649-0150-06 No Medicaid data
Drug total (last 4 qtrs): 17,607 Rx · 1,497,981 units · $40,263,521 gross reimbursed
Tap a pack size to open its page. Source: CMS State Drug Utilization Data, last 4 quarters.

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

Medicare Part D (outpatient prescription) spending for Relistor — 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 Relistor. 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
$29.53M
Claims incl. refills
11K
Beneficiaries
6.4K
Spend / beneficiary
$4,649.89
Spend / claim
$2,675.68
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.

📦 Packaging — all sizes for this product

Package NDCDescription Per unit Per pack Marketing startStatus
65649-0150-06 You're viewing this 1 BOTTLE in 1 CARTON (65649-150-06) / 6 TABLET in 1 BOTTLE — — 2016-07-19 Active
65649-0150-90 90 TABLET in 1 BOTTLE (65649-150-90) $25.34 / ea $2,280.42 2016-07-19 Active

This pack shows little to no recent Medicaid volume — the 90 tablets pack carries most fills. See all packs ↓

Pack size FAQ

What quantity is in NDC 65649-0150-06?
NDC 65649-0150-06 is a 6-count package — 1 bottle in 1 carton / 6 tablet in 1 bottle.
What is the difference between NDC 65649-0150-06 and NDC 65649-0150-90?
Both are Relistor Methylnaltrexone bromide 150 mg Tablet — the drug itself is identical. NDC 65649-0150-06 is the 6-count package, while NDC 65649-0150-90 is the 90 tablets package.
What NDC number is used to bill for this package of Relistor Methylnaltrexone bromide 150 mg Tablet?
Bill NDC 65649-0150-06 — the 11-digit billing format is 65649015006. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

Prices are the latest CMS NADAC pharmacy acquisition cost per NDC; per-pack figures are per-unit × pack quantity, shown only when the pack is denominated in the same measure NADAC prices.

🧭 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) — Not published for this NDC The labeler did not submit a structured excipient list, or no SPL is 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 FDA registers it as 65649-150-06, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 65649-0150-06, written without dashes as 65649015006. The Identity section at the top of this page lists every form of this code.
What do the three segments of this NDC mean?
In 65649-0150-06, the first segment (65649) is the labeler code FDA assigned to Salix Pharmaceuticals, Inc.; the middle segment (0150) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (06) identifies this exact package size and type. Together they name one specific package of one specific product.
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 Salix Pharmaceuticals, Inc.. Listing status can change — the directory data on this page refreshes weekly.
Does this product come in other package sizes?
Yes — the FDA directory lists 1 other package presentation of this same product, including 90 tablets (65649-0150-90). Each has its own NDC and its own page — see the package list near the top of this page.
Who lists this product with the FDA?
Salix Pharmaceuticals, Inc. 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.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. 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 💬 Medication Guide
🎯 Indications and Usage 178 words ▾

1 INDICATIONS AND USAGE • RELISTOR is an opioid antagonist. RELISTOR tablets and RELISTOR injection are indicated for the treatment of opioid-induced constipation (OIC) in adults with chronic non-cancer pain, including patients with chronic pain related to prior cancer or its treatment who do not require frequent (e.g., weekly) opioid dosage escalation. ( 1.1 ) • RELISTOR injection is indicated for the treatment of OIC in adults with advanced illness or pain caused by active cancer who require opioid dosage escalation for palliative care.

( 1.2 )

1.1Opioid-Induced Constipation in Adult Patients with Chronic Non-Cancer Pain RELISTOR tablets and RELISTOR injection are indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic non-cancer pain, including patients with chronic pain related to prior cancer or its treatment who do not require frequent (e.g., weekly) opioid dosage escalation.

1.2Opioid-Induced Constipation in Adult Patients with Advanced Illness RELISTOR injection is indicated for the treatment of OIC in adult patients with advanced illness or pain caused by active cancer who require opioid dosage escalation for palliative care.

⏱️ Dosage and Administration ~3 min read ▾

2 DOSAGE AND ADMINISTRATION Administration Instructions ( 2.1 ) • Be within close proximity to toilet facilities once administered. • Discontinue if treatment with opioid pain medication is also discontinued. • In adult patients with chronic non-cancer pain and OIC: o Patients receiving opioids for less than 4 weeks may be less responsive to RELISTOR. o Discontinue all maintenance laxative therapy before starting RELISTOR; may resume laxatives if there is a suboptimal response to RELISTOR after 3 days. o Re-evaluate the continued need for RELISTOR when opioid regimen is changed to avoid adverse reactions. • In patients with chronic non-cancer pain and OIC, take RELISTOR tablets with water on an empty stomach at least 30 minutes before the first meal of the day.

Dosing • For OIC in adult patients with chronic non-cancer pain ( 2.2 ): o RELISTOR tablets: The recommended dosage is 450 mg once daily in the morning. o RELISTOR injection: The recommended dosage is 12 mg subcutaneously once daily. • For OIC in adult patients with advanced illness ( 2.3 ): o The pre-filled syringe is only for patients who require a RELISTOR injection dose of 8 mg or 12 mg. Use the vial for patients who require other doses of RELISTOR injection. o RELISTOR injection: See Table 1 in the full prescribing information for the recommended dosage; administer one dose every other day, as needed, but no more frequently than one dose in a 24-hour period.

Dosage Adjustment • See full prescribing information dosage adjustment in renal or hepatic impairment by indication. ( 2.4 , 2.5 ) Preparation and Administration of RELISTOR Injection ( 2.6 ) • For subcutaneous use only. • Inject in upper arm, abdomen or thigh. Rotate injection sites.

2.1Important Administration Information • Be within close proximity to toilet facilities once RELISTOR is administered. • Discontinue RELISTOR if treatment with the opioid pain medication is also discontinued. • In adult patients with chronic non-cancer pain and OIC: o Patients receiving opioids for less than 4 weeks may be less responsive to RELISTOR [see Clinical Studies ( 14.1 )]. o Discontinue all maintenance laxative therapy prior to initiation of RELISTOR. Laxative(s) can be used as needed if there is a suboptimal response to RELISTOR after three days. o Re-evaluate the continued need for RELISTOR when the opioid regimen is changed to avoid adverse reactions. o In patients with chronic non-cancer pain and OIC, take RELISTOR tablets with water on an empty stomach at least 30 minutes before the first meal of the day.

2.2Opioid-Induced Constipation in Adult Patients with Chronic Non-Cancer Pain • The recommended dosage of RELISTOR tablets is 450 mg taken orally once daily in the morning. • The recommended dosage of RELISTOR injection is 12 mg administered subcutaneously once daily.

2.3Opioid-Induced Constipation in Adult Patients with Advanced Illness The pre-filled syringe is only for patients who require a RELISTOR injection dose of 8 mg or 12 mg. Use the vial for patients who require other doses of RELISTOR injection. Table 1 below shows the recommended weight-based dose of RELISTOR injection and the corresponding injection volume.

The recommended dosage regimen is one dose administered subcutaneously every other day, as needed. Do not administer more frequently than one dose per 24-hour period. Table 1: Weight-Based Dosing of RELISTOR Injection and Corresponding Injection Volume for Adult Patients with OIC and Advanced Illness Weight of Adult Patient Subcutaneous Dose Injection Volume Less than 38 kg 0.15 mg/kg See below* 38 kg to less than 62 kg 8 mg 0.4 mL 62 kg to 114 kg 12 mg 0.6 mL More than 114 kg 0.15 mg/kg See below* *Calculate the injection volume for these patients by multiplying the patient weight in kilograms by 0.0075 and then rounding up the volume to the nearest 0.1 mL.

2.4Dosage in Patients with Renal Impairment The recommended dosage of RELISTOR in patients with moderate and severe renal impairment (i.e…

💊 Dosage Forms and Strengths 118 words ▾

3 DOSAGE FORMS AND STRENGTHS • Tablets : • 150 mg methylnaltrexone bromide supplied as film-coated, white, round, biconvex, debossed with “REL” on one side and plain on the other side. Injection : Single-dose Vial: • 12 mg/0.6 mL methylnaltrexone bromide supplied as colorless to pale yellow solution. Single-dose Pre-filled Syringe: • 8 mg/0.4 mL methylnaltrexone bromide supplied as colorless to pale yellow solution. • 12 mg/0.6 mL methylnaltrexone bromide supplied as colorless to pale yellow solution. • Tablets: 150 mg methylnaltrexone bromide.

( 3 ) • Injection: o 8 mg/0.4 mL methylnaltrexone bromide in single-dose pre-filled syringe. ( 3 ) o 12 mg/0.6 mL methylnaltrexone bromide in a single-dose pre-filled syringe, or single-dose vial. ( 3 )

⛔ Contraindications 56 words ▾

4 CONTRAINDICATIONS RELISTOR is contraindicated in patients with known or suspected gastrointestinal obstruction and patients at increased risk of recurrent obstruction, due to the potential for gastrointestinal perforation [see Warnings and Precautions ( 5.1 )] . Patients with known or suspected mechanical gastrointestinal obstruction and at increased risk of recurrent obstruction. ( 4 , 5.1 )

⚠️ Warnings and Cautions ~2 min read ▾

5 WARNINGS AND PRECAUTIONS • Gastrointestinal Perforation : Consider the overall risk benefit in patients with known or suspected lesions of the GI tract. Monitor for severe, persistent or worsening abdominal pain; discontinue if development of symptoms. ( 5.1 ) • Severe or Persistent Diarrhea : Discontinue if severe or persistent diarrhea occurs during treatment.

( 5.2 ) • Opioid Withdrawal : Consider the overall risk benefit in patients with disruptions to the blood-brain barrier. Monitor closely for symptoms of opioid withdrawal. ( 5.3 )

5.1Gastrointestinal Perforation Cases of gastrointestinal perforation have been reported in adult patients with OIC and advanced illness with conditions that may be associated with localized or diffuse reduction of structural integrity in the wall of the gastrointestinal tract (e.g., peptic ulcer disease, Ogilvie’s syndrome, diverticular disease, infiltrative gastrointestinal tract malignancies or peritoneal metastases). Take into account the overall risk-benefit profile when using RELISTOR in patients with these conditions or other conditions which might result in impaired integrity of the gastrointestinal tract wall (e.g., Crohn’s disease).

Monitor for the development of severe, persistent, or worsening abdominal pain; discontinue RELISTOR in patients who develop this symptom [see Contraindications ( 4 )].

5.2Severe or Persistent Diarrhea If severe or persistent diarrhea occurs during treatment, advise patients to discontinue therapy with RELISTOR and consult their healthcare provider.

5.3Opioid Withdrawal Symptoms consistent with opioid withdrawal, including hyperhidrosis, chills, diarrhea, abdominal pain, anxiety, and yawning have occurred in patients treated with RELISTOR [see Adverse Reactions ( 6.1 )] . Patients having disruptions to the blood-brain barrier may be at increased risk for opioid withdrawal and/or reduced analgesia. Take into account the overall risk-benefit profile when using RELISTOR in such patients.

Monitor for adequacy of analgesia and symptoms of opioid withdrawal in such patients.

5.1Gastrointestinal Perforation Cases of gastrointestinal perforation have been reported in adult patients with OIC and advanced illness with conditions that may be associated with localized or diffuse reduction of structural integrity in the wall of the gastrointestinal tract (e.g., peptic ulcer disease, Ogilvie’s syndrome, diverticular disease, infiltrative gastrointestinal tract malignancies or peritoneal metastases). Take into account the overall risk-benefit profile when using RELISTOR in patients with these conditions or other conditions which might result in impaired integrity of the gastrointestinal tract wall (e.g., Crohn’s disease).

Monitor for the development of severe, persistent, or worsening abdominal pain; discontinue RELISTOR in patients who develop this symptom [see Contraindications ( 4 )].

5.2Severe or Persistent Diarrhea If severe or persistent diarrhea occurs during treatment, advise patients to discontinue therapy with RELISTOR and consult their healthcare provider.

🤒 Adverse Reactions ~3 min read ▾

6 ADVERSE REACTIONS Serious and important adverse reactions described elsewhere in the labeling include: • Gastrointestinal perforation [see Warnings and Precautions ( 5.1 )] • Severe or persistent diarrhea [see Warnings and Precautions ( 5.2 )] • Opioid withdrawal [see Warnings and Precautions ( 5.3 )] The most common adverse reactions are: OIC in adult patients with chronic non-cancer pain ( 6.1 ) • RELISTOR tablets (≥ 2%): abdominal pain, diarrhea, headache, abdominal distention, vomiting, hyperhidrosis, anxiety, muscle spasms, rhinorrhea, and chills. • RELISTOR injection (≥ 1%): abdominal pain, nausea, diarrhea, hyperhidrosis, hot flush, tremor, and chills.

OIC in adult patients with advanced illness ( 6.1 ) • RELISTOR injection (≥ 5%): abdominal pain, flatulence, nausea, dizziness, and diarrhea. 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 clinical practice. Opioid-Induced Constipation in Adult Patients with Chronic Non-Cancer Pain The safety of RELISTOR tablets was evaluated in a double-blind, placebo-controlled trial in adult patients with OIC and chronic non-cancer pain receiving opioid analgesia.

This study (Study 1) included a 12-week, double-blind, placebo-controlled period in which adult patients were randomized to receive RELISTOR tablets 450 mg orally (200 patients) or placebo (201 patients) [see Clinical Studies ( 14.1 ) ] . After 4 weeks of double-blind treatment administered once daily, patients continued 8 weeks of double-blind treatment on an as needed basis (but not more than once daily). The most common adverse reactions in adult patients with OIC and chronic non-cancer pain receiving RELISTOR tablets are shown in Table 4 .

Adverse reactions of abdominal pain, diarrhea, hyperhidrosis, anxiety, rhinorrhea, and chills may reflect symptoms of opioid withdrawal. Table 4: Adverse Reactions* in 4-Week Double-Blind, Placebo-Controlled Period of Clinical Study of RELISTOR Tablets in Adult Patients with OIC and Chronic Non-Cancer Pain (Study 1) Adverse Reaction RELISTOR Tablets n = 200 Placebo n = 201 Abdominal Pain ** 14% 10% Diarrhea 5% 2% Headache 4% 3% Abdominal Distention 4% 2% Vomiting 3% 2% Hyperhidrosis 3% 1% Anxiety 2% 1% Muscle Spasms 2% 1% Rhinorrhea 2% 1% Chills 2% 0% * Adverse reactions occurring in at least 2% of patients receiving RELISTOR tablets 450 mg once daily and at an incidence greater than placebo. ** Includes: abdominal pain, upper abdominal pain, lower abdominal pain, abdominal discomfort and abdominal tenderness The safety of RELISTOR injection was evaluated in a double-blind, placebo-controlled trial in adult patients with OIC and chronic non-cancer pain receiving opioid analgesia.

This study (Study 2) included a 4-week, double-blind, placebo-controlled period in which adult patients were randomized to receive RELISTOR injection 12 mg subcutaneously once daily (150 patients) or placebo (162 patients) [see Clinical Studies ( 14.1 )] . After 4 weeks of double-blind treatment, patients began an 8‑week open-label treatment period during which RELISTOR injection 12 mg subcutaneously was administered less frequently than the recommended dosage regimen of 12 mg once daily. The most common adverse reactions in adult patients with OIC and chronic non-cancer pain receiving RELISTOR injection are shown in Table 5 .

The adverse reactions in the table below may reflect symptoms of opioid withdrawal. Table 5: Adverse Reactions* in 4-Week Double-Blind, Placebo-Controlled Period of Clinical Study of RELISTOR Injection in Adult Patients with OIC and Chronic Non-Cancer Pain (Study 2) Adverse Reaction RELISTOR Injection n = 150 Placebo n…

🔄 Drug Interactions 142 words ▾

7 DRUG INTERACTIONS • Other Opioid Antagonists : Potential for additive effect and increased risk of opioid withdrawal; avoid concomitant use. ( 7.1 )

7.1Other Opioid Antagonists Avoid concomitant use of RELISTOR with other opioid antagonists because of the potential for additive effects of opioid receptor antagonism and increased risk of opioid withdrawal.

7.2Drugs Metabolized by Cytochrome P450 Isozymes In healthy subjects, a subcutaneous dose of 0.3 mg/kg of RELISTOR did not significantly affect the metabolism of dextromethorphan, a CYP2D6 substrate.

7.1Other Opioid Antagonists Avoid concomitant use of RELISTOR with other opioid antagonists because of the potential for additive effects of opioid receptor antagonism and increased risk of opioid withdrawal.

7.2Drugs Metabolized by Cytochrome P450 Isozymes In healthy subjects, a subcutaneous dose of 0.3 mg/kg of RELISTOR did not significantly affect the metabolism of dextromethorphan, a CYP2D6 substrate.

👥 Use in Specific Populations ~3 min read ▾

8 USE IN SPECIFIC POPULATIONS • Pregnancy : May precipitate opioid withdrawal in a fetus ( 8.1 ) • Lactation : Breastfeeding not recommended. ( 8.2 )

8.1Pregnancy Risk Summary The limited available data with RELISTOR in pregnant women are not sufficient to inform a drug-associated risk for major birth defects and miscarriages. There are clinical considerations when RELISTOR is used by pregnant women [see Clinical Considerations]. In animal reproduction studies, no effects on embryofetal development were observed with the administration of intravenous methylnaltrexone bromide during organogenesis in rats and rabbits at doses up to 20 times and 26 times, respectively, the subcutaneous maximum recommended human dose (MRHD) of 12 mg RELISTOR injection per day.

The intravenous doses in rats and rabbits are about 0.5 times and 0.7 times, respectively, the oral MRHD of 450 mg/day [see Data]. Advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown.

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. Clinical Considerations Fetal/Neonatal Adverse Reactions The use of RELISTOR during pregnancy may precipitate opioid withdrawal in a fetus due to the immature fetal blood-brain barrier. Data Animal Data Reproduction studies have been performed with methylnaltrexone bromide administered during the period of organogenesis to rats at intravenous doses up to 25 mg/kg/day (about 20 times the subcutaneous MRHD of 12 mg/day based on body surface area), and did not cause any adverse effects on embryofetal development.

In rabbits, intravenous doses of methylnaltrexone bromide up to 16 mg/kg/day (about 26 times the subcutaneous MRHD of 12 mg/day) did not show any embryofetal toxicity. The intravenous doses in rats (25 mg/kg/day) and rabbits (16 mg/kg/day) are about 0.5 and 0.7 times, respectively, the oral MRHD of 450 mg/day based on body surface area. A pre- and postnatal development study in rats showed no evidence of any adverse effect on pre- and postnatal development at subcutaneous doses of methylnaltrexone bromide up to 100 mg/kg/day (about 81 times the subcutaneous MRHD of 12 mg/day; about 2.2 times the oral MRHD of 450 mg/day).

8.2Lactation Risk Summary There is no information regarding the presence of methylnaltrexone in human milk, the effects on the breastfed infant, or the effects on milk production. Methylnaltrexone is present in rat milk [see Data]. Because of the potential for serious adverse reactions, including opioid withdrawal, in breastfed infants, advise women that breastfeeding is not recommended during treatment with RELISTOR.

Data Radioactivity appeared in rat milk within 30 minutes of a single subcutaneous administration of radiolabeled methylnaltrexone bromide and was concentrated up to 24-fold at 8 hours after administration relative to plasma concentrations.

8.4Pediatric Use Safety and effectiveness of RELISTOR tablets and injection have not been established in pediatric patients. Juvenile Animal Studies In juvenile rats administered intravenous methylnaltrexone bromide for 13 weeks, adverse clinical signs such as convulsions, tremors and labored breathing were observed, and the juvenile rats were found to be more sensitive to the adverse effects of methylnaltrexone when compared to adult animals. Juvenile dogs administered intravenous methylnaltrexone bromide for 13 weeks had a toxicity profile similar to adult dogs [see Nonclinical Toxicology ( 13.2 )].

8.5Geriatric Use Of the total number of patients in clinical studies of RELISTOR tablets, a total of 136 patients (10%) were aged 65 years and older, while 23 (2%) were aged 75 and older. In clinical studies of RELISTOR tablets, no overall differences in effectiveness were observed. Adverse reactions were similar; however, there was a…

🤰 Pregnancy ~2 min read ▾

8.1Pregnancy Risk Summary The limited available data with RELISTOR in pregnant women are not sufficient to inform a drug-associated risk for major birth defects and miscarriages. There are clinical considerations when RELISTOR is used by pregnant women [see Clinical Considerations]. In animal reproduction studies, no effects on embryofetal development were observed with the administration of intravenous methylnaltrexone bromide during organogenesis in rats and rabbits at doses up to 20 times and 26 times, respectively, the subcutaneous maximum recommended human dose (MRHD) of 12 mg RELISTOR injection per day.

The intravenous doses in rats and rabbits are about 0.5 times and 0.7 times, respectively, the oral MRHD of 450 mg/day [see Data]. Advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown.

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. Clinical Considerations Fetal/Neonatal Adverse Reactions The use of RELISTOR during pregnancy may precipitate opioid withdrawal in a fetus due to the immature fetal blood-brain barrier. Data Animal Data Reproduction studies have been performed with methylnaltrexone bromide administered during the period of organogenesis to rats at intravenous doses up to 25 mg/kg/day (about 20 times the subcutaneous MRHD of 12 mg/day based on body surface area), and did not cause any adverse effects on embryofetal development.

In rabbits, intravenous doses of methylnaltrexone bromide up to 16 mg/kg/day (about 26 times the subcutaneous MRHD of 12 mg/day) did not show any embryofetal toxicity. The intravenous doses in rats (25 mg/kg/day) and rabbits (16 mg/kg/day) are about 0.5 and 0.7 times, respectively, the oral MRHD of 450 mg/day based on body surface area. A pre- and postnatal development study in rats showed no evidence of any adverse effect on pre- and postnatal development at subcutaneous doses of methylnaltrexone bromide up to 100 mg/kg/day (about 81 times the subcutaneous MRHD of 12 mg/day; about 2.2 times the oral MRHD of 450 mg/day).

🧒 Pediatric Use 87 words ▾

8.4Pediatric Use Safety and effectiveness of RELISTOR tablets and injection have not been established in pediatric patients. Juvenile Animal Studies In juvenile rats administered intravenous methylnaltrexone bromide for 13 weeks, adverse clinical signs such as convulsions, tremors and labored breathing were observed, and the juvenile rats were found to be more sensitive to the adverse effects of methylnaltrexone when compared to adult animals. Juvenile dogs administered intravenous methylnaltrexone bromide for 13 weeks had a toxicity profile similar to adult dogs [see Nonclinical Toxicology ( 13.2 )].

🧓 Geriatric Use 143 words ▾

8.5Geriatric Use Of the total number of patients in clinical studies of RELISTOR tablets, a total of 136 patients (10%) were aged 65 years and older, while 23 (2%) were aged 75 and older. In clinical studies of RELISTOR tablets, no overall differences in effectiveness were observed. Adverse reactions were similar; however, there was a higher incidence of diarrhea in elderly patients.

Of the total number of patients in clinical studies of RELISTOR injection, a total of 226 (28%) were aged 65 years and older, while 108 (13%) were aged 75 years and older. In clinical studies of RELISTOR injection, no overall differences in safety or effectiveness were observed between elderly patients and younger patients. Based on pharmacokinetic data, and safety and efficacy data from controlled clinical trials, no dosage adjustment based on age is recommended.

Monitor elderly patients for adverse reactions.

🆘 Overdosage 123 words ▾

10 OVERDOSAGE During clinical trials of RELISTOR administered orally and subcutaneously, one accidental case of methylnaltrexone bromide overdose was reported and no adverse events were reported as a result of the overdosage. A study of healthy subjects noted orthostatic hypotension associated with a dose of 0.64 mg/kg administered as an intravenous bolus. Monitor for signs or symptoms of orthostatic hypotension and initiate treatment as appropriate.

If a patient on opioid therapy receives an overdose of RELISTOR, the patient should be monitored closely for potential evidence of opioid withdrawal symptoms such as chills, rhinorrhea, diaphoresis or reversal of central analgesic effect. Base treatment on the degree of opioid withdrawal symptoms, including changes in blood pressure and heart rate, and on the need for analgesia.

🧬 Clinical Pharmacology ~3 min read ▾

12 CLINICAL PHARMACOLOGY

12.1Mechanism of Action Methylnaltrexone is a selective antagonist of opioid binding at the mu-opioid receptor. As a quaternary amine, the ability of methylnaltrexone to cross the blood-brain barrier is restricted. This allows methylnaltrexone to function as a peripherally-acting mu-opioid receptor antagonist in tissues such as the gastrointestinal tract, thereby decreasing the constipating effects of opioids without impacting opioid-mediated analgesic effects on the central nervous system (CNS).

12.2Pharmacodynamics Cardiac Electrophysiology In a randomized, double-blind placebo- and (open-label) moxifloxacin-controlled 4-period crossover study, 56 healthy subjects were administered methylnaltrexone bromide 0.3 mg/kg and methylnaltrexone bromide 0.64 mg/kg by intravenous infusion over 20 minutes (RELISTOR is not approved for intravenous use), placebo, and a single oral dose of moxifloxacin. At a dose approximately 4.3 times the maximum recommended dose (7.5 times the mean peak plasma concentration for RELISTOR injection and 22 times the peak plasma concentration for RELISTOR tablets), methylnaltrexone does not prolong the QTc interval to any clinically relevant extent.

12.3Pharmacokinetics Between the oral dosage range of 150 mg to 450 mg for RELISTOR tablets and the subcutaneous dosage range of 0.15 mg/kg to 0.50 mg/kg for RELISTOR injection, the mean C max and area under the plasma concentration-time curve (AUC) of methylnaltrexone increased in a dose-proportional manner. There was no significant accumulation of methylnaltrexone following once-daily oral dosing of 450 mg RELISTOR tablets or subcutaneous dosing of 12 mg RELISTOR injection for seven consecutive days in healthy subjects.

Absorption Tablets Following administration of a single 450 mg dose of RELISTOR tablets in OIC patients or healthy subjects, peak concentrations (C max ) of methylnaltrexone were observed at approximately 1.5 hours. The absolute bioavailability of oral methylnaltrexone bromide has not been determined. The C max and AUC in healthy subjects were 48.1 ng/mL and 382 ng·hr/mL, respectively, following a single 450 mg dose of RELISTOR tablets.

Exposure in the OIC patient population was approximately 27% lower than in healthy subjects. Food Effect Administration of a single 450 mg dose of RELISTOR tablets to healthy subjects with a high-fat breakfast (containing approximately 800 to 1000 total calories, with 60%, 25% and 15% of calories derived from fat, carbohydrate and protein, respectively) resulted in a decrease in the C max of methylnaltrexone by 60%, the AUC by 43% and delayed the T max by 2 hours [see Dosage and Administration ( 2.1 )] . Injection Following administration of RELISTOR injection subcutaneously, methylnaltrexone achieved peak concentrations (C max ) at approximately 0.5 hours (see Table 7 ).

Table 7: Pharmacokinetic Parameters of Methylnaltrexone Following Subcutaneous Doses Parameter 0.15 mg/kg Single Dose 12 mg Single Dose 12 mg at Steady-State C max (ng/mL) i 117 (32.7) 140 (35.6) 119 (27.2) T max (hr) ii 0.5 (0.25 to 0.75) 0.25 (0.25 to 0.5) 0.25 (0.25 to 0.5) AUC 24 (ng·hr/mL) i 175 (36.6) 218 (28.3) 223 (28.2) ⁱ Expressed as mean (SD). ⁱⁱ Expressed as median (range). Distribution The steady-state volume of distribution (Vss) of methylnaltrexone is approximately

1.1L/kg. The fraction of methylnaltrexone bound to human plasma proteins is 11% to 15%, as determined by equilibrium dialysis. Elimination Following oral administration of a single 450 mg dose of RELISTOR tablets, concentrations of methylnaltrexone declined in multiphasic manner with a terminal half-life (t 1/2 ) of approximately 15 hours.

Metabolism In an intravenous mass balance study, approximately 44% of the administered radioactivity was recovered in the urine over 24 hours with 5 distinct metabolites. None of the detected metabolites was in amounts over 6% of administered radioactivity. Conversion to methyl-6-naltrexol isomers (5% of…

🧬 Mechanism of Action 67 words ▾

12.1Mechanism of Action Methylnaltrexone is a selective antagonist of opioid binding at the mu-opioid receptor. As a quaternary amine, the ability of methylnaltrexone to cross the blood-brain barrier is restricted. This allows methylnaltrexone to function as a peripherally-acting mu-opioid receptor antagonist in tissues such as the gastrointestinal tract, thereby decreasing the constipating effects of opioids without impacting opioid-mediated analgesic effects on the central nervous system (CNS).

📦 How Supplied / Storage and Handling 189 words ▾

16 HOW SUPPLIED/STORAGE AND HANDLING How Supplied NDC Number Pack Size Contents 65649-150-90 90-count bottle 100-mL bottle containing 90 tablets and 2 silica gel desiccant canisters. Each 150 mg film-coated tablet is white, round, biconvex, and debossed with “REL” on one side and plain on the other side. 65649-551-02 1 vial per carton One 12 mg/0.6 mL single-dose vial containing a colorless to pale yellow solution.

65649-552-04 7 pre-filled syringes per carton Seven 8 mg/0.4 mL single-dose pre-filled syringes with needle guard system containing a colorless to pale yellow solution. 65649-551-03 7 pre-filled syringes per carton Seven 12 mg/0.6 mL single-dose pre-filled syringes with needle guard system containing a colorless to pale yellow solution. 65649-551-07 1 pre-filled syringe per carton One 12 mg/0.6 mL single-dose pre-filled syringe with needle guard system containing a colorless to pale yellow solution.

Storage Tablets Store at up to 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature]. Injection Store 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]. Do not freeze.

Protect from light.

📋 Description ~1 min read ▾

11 DESCRIPTION RELISTOR ® (methylnaltrexone bromide) is a mu-opioid receptor antagonist. The chemical name for methylnaltrexone bromide is ( R )- N -(cyclopropylmethyl) noroxymorphone methobromide. The molecular formula is C 21 H 26 NO 4 Br, and the molecular weight is 436.36.

The structural formula is: RELISTOR tablets for oral administration are film-coated and contain 150 mg of methylnaltrexone bromide (equivalent to 122.5 mg methylnaltrexone). Inactive ingredients are silicified microcrystalline cellulose, microcrystalline cellulose, sodium lauryl sulfate, croscarmellose sodium, crospovidone, poloxamer 407, stearic acid (vegetable source), colloidal silicon dioxide, edetate calcium disodium, polyvinyl alcohol, titanium dioxide, polyethylene glycol and talc. RELISTOR for subcutaneous administration is a sterile, clear and colorless to pale yellow aqueous solution.

Each 3 mL vial contains 12 mg of methylnaltrexone bromide (equivalent to 9.8 mg of methylnaltrexone) in 0.6 mL of water. The excipients are 3.9 mg sodium chloride USP, 0.24 mg edetate calcium disodium USP, and 0.18 mg glycine hydrochloride. During manufacture, the pH may have been adjusted with hydrochloric acid and/or sodium hydroxide.

Each 8 mg/0.4 mL pre-filled syringe (1 mL syringe) contains 8 mg of methylnaltrexone bromide (equivalent to 6.5 mg of methylnaltrexone) in 0.4 mL of water. The excipients are 2.6 mg sodium chloride USP, 0.16 mg edetate calcium disodium USP, and 0.12 mg glycine hydrochloride. Each 12 mg/0.6 mL pre-filled syringe (1 mL syringe) contains 12 mg of methylnaltrexone bromide (equivalent to 9.8 mg of methylnaltrexone) in 0.6 mL of water.

The excipients are 3.9 mg sodium chloride USP, 0.24 mg edetate calcium disodium USP, and 0.18 mg glycine hydrochloride. chemstructure

💬 Information for Patients ~2 min read ▾

17 PATIENT COUNSELING INFORMATION Advise the patient to read the FDA-approved patient labeling (Medication Guide and Instructions for Use). Administration • Be within close proximity to toilet facilities once RELISTOR is administered. • Discontinue RELISTOR if treatment with the opioid pain medication is also discontinued. • Advise chronic non-cancer pain patients receiving RELISTOR for OIC to: o Discontinue all maintenance laxative therapy prior to initiation of RELISTOR. Laxative(s) can be used as needed if there is a suboptimal response to RELISTOR after 3 days. o Inform their healthcare provider if their opioid regimen is changed, to avoid adverse reactions, such as diarrhea.

Tablets Advise patients with chronic non-cancer pain receiving RELISTOR tablets for OIC to take RELISTOR tablets once daily with water on an empty stomach at least 30 minutes before the first meal of the day. Injection • Advise all patients receiving RELISTOR injection to: o Inject RELISTOR subcutaneously in the upper arm, abdomen or thigh. Do not inject at the same spot each time (rotate injection sites). o Safely dispose of needles by following the sharps disposal recommendations described in the Instructions for Use . • Advise chronic non-cancer pain patients receiving RELISTOR injection for OIC to inject one dose every day. • Advise patients with advanced illness receiving RELISTOR injection for OIC to inject one dose every other day, as needed, but no more frequently than one dose in a 24-hour period.

Gastrointestinal Perforation Advise patients to discontinue RELISTOR and to promptly seek medical attention if they develop unusually severe, persistent, or worsening abdominal pain [see Warnings and Precautions ( 5.1 )] . Severe or Persistent Diarrhea Advise patients to discontinue RELISTOR if they experience severe or persistent diarrhea [ see Warnings and Precautions (5.2 )]. Opioid Withdrawal Advise patients that symptoms consistent with opioid withdrawal may occur while taking RELISTOR, including sweating, chills, diarrhea, abdominal pain, anxiety, and yawning [see Warnings and Precautions ( 5.3 ), Adverse Reactions ( 6.1 )].

Pregnancy Fetal Opioid Withdrawal Advise females of reproductive potential, who become pregnant or are planning to become pregnant, that the use of RELISTOR during pregnancy may precipitate opioid withdrawal in a fetus due to the undeveloped blood-brain barrier [see Use in Specific Populations ( 8.1 )] . Lactation Advise patients that breastfeeding is not recommended during treatment with RELISTOR [ see Use in Specific Populations ( 8.2 )] . Distributed by: Salix Pharmaceuticals, a division of Bausch Health US, LLC Bridgewater, NJ 08807 USA Under license from: Progenics Pharmaceuticals, Inc.

Tarrytown, NY 10591 USA For Injection: Patented. See https://patents.salix.com for US patent information. For Tablets: Patented.

See https://patents.salix.com for US patent information. For more information, go to www.RELISTOR.com or call 1-800-321-4576. RELISTOR is a trademark of Salix Pharmaceuticals, Inc. or its affiliates.

All other product/brand names and/or logos are trademarks of the respective owners. © 2024 Salix Pharmaceuticals, Inc. or its affiliates 9502506 70014843-01 logo logo

💬 Medication Guide ~3 min read ▾

MEDICATION GUIDE MEDICATION GUIDE RELISTOR ® (rel-i–store) (methylnaltrexone bromide) tablets and RELISTOR (rel-i–store) (methylnaltrexone bromide) injection, for subcutaneous use What is the most important information I should know about RELISTOR? RELISTOR can cause serious side effects, including: • Tear in your stomach or intestinal wall (perforation). Stomach pain that is severe can be a sign of a serious medical condition.

If you get stomach pain that is severe, does not go away, or gets worse, stop taking RELISTOR and get emergency medical help right away. • Diarrhea that is severe or that will not go away. Stop taking RELISTOR and call your healthcare provider if you get diarrhea that is severe or that does not go away during treatment with RELISTOR. • Opioid withdrawal. You may have symptoms of opioid withdrawal during treatment with RELISTOR including sweating, chills, diarrhea, stomach pain, anxiety, and yawning.

Tell your healthcare provider if you have any of these symptoms. What is RELISTOR? RELISTOR is a prescription medicine used to treat constipation in adults that is caused by prescription pain medicines called opioids: • RELISTOR tablets and RELISTOR injection are used to treat constipation caused by opioids in adults with long-lasting (chronic) pain that is not caused by active cancer. • RELISTOR injection is used to treat constipation caused by opioids in adults with advanced illness or pain caused by active cancer and who need increases in their opioid dose for comfort care.

It is not known if RELISTOR is safe and effective in children. Who should not use RELISTOR? Do not use RELISTOR if you have a bowel blockage (intestinal obstruction) or have a history of bowel blockage.

What should I tell my healthcare provider before taking RELISTOR? Before you start taking RELISTOR, tell your healthcare provider about all of your medical conditions, including if you: • have kidney problems. • have liver problems. • have any stomach or bowel (intestines) problems, including stomach ulcer, Crohn’s disease, diverticulitis, cancer of the stomach or bowel, or Ogilvie’s syndrome. • are pregnant or plan to become pregnant. Taking RELISTOR during pregnancy may cause opioid withdrawal symptoms in your unborn baby.

Tell your healthcare provider right away if you become pregnant during treatment with RELISTOR. • are breastfeeding or plan to breastfeed. It is not known if RELISTOR passes into your breast milk. Taking RELISTOR while you are breastfeeding may cause opioid withdrawal in your baby.

You should not breastfeed during treatment with RELISTOR. Tell your healthcare provider about all of the medicines you take , including prescription and over-the-counter medicines, vitamins, and herbal supplements. How should I take RELISTOR? • Stay close to a toilet after taking RELISTOR. • Stop taking RELISTOR if you stop taking your prescription opioid pain medicine.

Tell your healthcare provider if your pain medicine changes. • If you take too much RELISTOR, call your healthcare provider or go to the nearest emergency room right away. • If you take RELISTOR for long-lasting (chronic) pain that is not caused by cancer: o RELISTOR has been shown to be effective in people who have taken opioid pain medicines for at least 4 weeks to treat long-lasting (chronic) pain not caused by cancer. o Stop taking other laxatives before you start treatment with RELISTOR. You may use other laxatives if RELISTOR does not work after 3 days of treatment.

Tablets: • Take RELISTOR tablets 1 time each day with water. Take RELISTOR tablets on an empty stomach at least 30 minutes before your first meal of the day. Injection (Vials and Pre-filled Syringes): See the detailed “Instructions for Use” that comes with RELISTOR injection for information about how to prepare and inject RELISTOR injection, and properly throw away (dispose of) used needles and syringes the right way. • RELISTOR injection is injected under the skin (subcutaneous injection) of the upper ar…

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