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Letairis AMBRISENTAN 5 mg Tablet, Film Coated, 10-count — NDC 61958-0801-06 package photo

Letairis AMBRISENTAN 5 mg Tablet, Film Coated, 10-count

by Gilead Sciences, Inc. · 10 TABLET, FILM COATED in 1 BOTTLE, PLASTIC (61958-0801-6)
NDC 61958-0801-06
🏷️ FDA NDC (as labeled) 61958-0801-6 billing pads the package segment with a zero
This package
Contains10-count Pack sizes6 compare ↓
Also priced by: Part D plans $491.02/unit — full pricing hub ↓
Also comes in: 10 tablets 61958-0801-02 10 tablets 61958-0801-03 10 tablets 61958-0801-04 10 tablets 61958-0801-05 30 tablets 61958-0801-01
Rx only Brand On market Non-controlled 🛡 REMS
🗂️ 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) 61958-0801-6
Product NDC 61958-0801
11-digit billing NDC 61958080106
RxCUI 722116, 722120, 722122, 722124
UNII HW6NV07QEC
Application # NDA022081
SPL Set ID 725d4e73-6c83-477a-adc6-0ae4a133a844
Established class (EPC) Endothelin Receptor Antagonist
Mechanism of action Endothelin Receptor Antagonists
DEA schedule Non-controlled
Marketing category NDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2007-06-15
Route ORAL
Dosage form TABLET, FILM COATED
Substance AMBRISENTAN
GPI-14 40160007000310
GCN Seq No 062792
GCN 98566
HICL code 034849
Ingredient (HICL) Ambrisentan
HIC1 code B
Therapeutic class — broad (HIC1) Respiratory System
HIC2 code B1
Therapeutic class — intermediate (HIC2) Affect Primarily Lungs
HIC3 code B1B
Therapeutic class — specific (HIC3) Pulmonary Anti-Htn, Endothelin Receptor Antagonist
AHFS code 24:12.92.00
AHFS class Vasodilating Agents, Miscellaneous
FDB label name LETAIRIS 5 MG TABLET
FDB brand name Letairis
Legend status F — Federal legend — prescription drug or device
TE code (Orange Book) AB · RLD · RS
Why two NDCs? The FDA registers this code as 61958-0801-6 — 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 → 61958-0801-06. 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 Endothelin Receptor Antagonist class.

Pharmacologic class Endothelin Receptor Antagonist
Drug family (ATC) Antihypertensives for pulmonary arterial hypertension
How it works Endothelin Receptor 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

LabelerGilead Sciences, Inc.
Application holderGILEAD SCIENCES INC
FDA applicationNDA022081 (NDA)
Labeler code61958
First marketedJun 2007
Product typeHuman Prescription Drug
Portfolio42 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 LETAIRIS 5 MG TABLET Ingredient Ambrisentan
📗 Our plain-language guide HelloPharmacist
  • Ambrisentan won't cure PAH, but it can make a real difference in how you feel and function. It works by blocking a protein called ET-1 that causes the blood vessels in your lungs t...
  • What exactly does ambrisentan do, and will it cure my PAH?
  • Good news — food doesn't affect how well your body absorbs ambrisentan, so you can take it with or without a meal, whichever works best for your routine. Pick a time of day you can...
  • Can I take ambrisentan with food, and does it matter what time of day I take it?
📖 Read our full Ambrisentan guide →
1
Nutrient depletion considerations

Ambrisentan may be associated with lower levels of 1 nutrient — worth a chat with your pharmacist, not a cause for alarm.

🧪 Full Ambrisentan 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.

💊 What it looks like

Color pink / red
ShapeOval
ImprintGSI;10
Size1 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 LMI26O6933
    Alumina is a white powder form of aluminum oxide. It's used as a filler to add bulk to tablets and capsules, and sometimes as a thickening or anti-caking agent in powdered formulations.
  • UNII M28OL1HH48
    Croscarmellose sodium is a plant-based substance derived from cellulose. It acts as a disintegrant, helping tablets and capsules break down quickly in the digestive system so the medicine can be absorbed.
  • UNII WZB9127XOA
    A synthetic red dye used to color medications and make them easier to identify. It serves as a colorant in tablets, capsules, and liquid formulations.
  • UNII EWQ57Q8I5X
    Lactose monohydrate is a natural sugar derived from milk. It serves as a filler and binder in tablets and capsules, helping create the proper size, texture, and consistency of the medicine.
  • UNII 70097M6I30
    Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
  • 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 G2M7P15E5P
    Polyethylene glycol 3350 is a synthetic polymer used as a solvent, humectant, and thickening agent in medicines. It helps dissolve other ingredients, retain moisture in the product, and achieve the desired consistency.
  • 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 1DI56QDM62
    A natural fatty substance from soybeans that helps mix oil and water-based ingredients together. It acts as an emulsifier and lubricant in medicines to improve texture and help the product break down properly in your body.
  • 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.

11 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.

💲 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 $491.02 $4,910.21 / 10 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
Ambrisentan 5 mg 00378-4270-93 Mylan 30 tablets — AB FDA listed —
Ambrisentan 5 mg 00591-2405-30 Actavis 30 tablets — AB FDA listed —
Ambrisentan 5 mg 42794-0051-08 Sigmapharm 30 tablets — AB FDA listed —
ambrisentan 5 mg 47335-0236-64 Sun 10 tablets — — FDA listed —
ambrisentan 5 mg 50090-7671-00 A-S 30 tablets — AB FDA listed —
Ambrisentan 5 mg 51407-0594-30 Golden 30 tablets — AB FDA listed —
ambrisentan 5 mg 59651-0494-30 Aurobindo 30 tablets — AB FDA listed —
Ambrisentan 5 mg 60505-4552-03 Apotex 30 tablets — AB FDA listed —
Letairis 5 mgthis 61958-0801-06 Gilead 10 tablets — AB FDA listed —
Ambrisentan 5 mg 69097-0386-02 Cipla 30 tablets — AB FDA listed —
Ambrisentan 5 mg 70710-1179-01 Zydus 100 tablets — AB FDA listed —
Ambrisentan 5 mg 70771-1363-01 Zydus 100 tablets — AB FDA listed —
Ambrisentan 5 mg 82009-0141-30 Quallent 30 tablets — AB FDA listed —
About this product: this is the brand-name version. FDA-approved generic versions are listed, and recent pricing/market data suggests they may be available.
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

🏛️
2007
First FDA approval
Jun 2007
📍
2026
Currently FDA-listed
19 years listed
🛡️
2031
Latest patent/protection listed
not a guaranteed launch date
✅Generic appears available

FDA-approved generic versions are listed, and recent pricing/market data suggests they may be available — see Therapeutic equivalents.

🛡️ Latest patent/protection date listed: FDA patent/protection data lists protections through Oct 2031. This may affect when a full generic version becomes widely available, but it is not a guaranteed launch date.
📅 FDA approved Jun 15, 2007 AB TE-rated RLD RS ⏳ ~5.1 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 9474752 — method of use (U-1754)
US 9474752 — method of use (U-1754)
US 9549926 — method of use (U-1965)
US 8377933 — method of use (U-1754)
US 8377933 — method of use (U-1754)
US 9549926 — method of use (U-1965)
2007 2009 2011 2013 2015 2017 2019 2021 2023 2025 2027 2029 2031
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 (6)
PatentTypeUse codeExpires
US 9474752 ↗ Method of use U-1754 Dec 11, 2027
US 9474752 ↗ Method of use U-1754 Dec 11, 2027
US 9549926 ↗ Method of use U-1965 Oct 14, 2031
US 8377933 ↗ Method of use U-1754 Dec 11, 2027
US 8377933 ↗ Method of use U-1754 Dec 11, 2027
US 9549926 ↗ Method of use U-1965 Oct 14, 2031
Common questions
Is there a generic version of LETAIRIS 5 MG TABLET?
Yes — an FDA-approved generic equivalent is listed in the FDA Orange Book for LETAIRIS 5 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.

💊 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.
30 tablets61958-0801-01 372 Rx · $4,708,469
10 tablets61958-0801-02 No Medicaid data
10 tablets61958-0801-03 No Medicaid data
10 tablets61958-0801-04 No Medicaid data
10 tablets61958-0801-05 No Medicaid data
10 tablets this page61958-0801-06 No Medicaid data
Drug total (last 4 qtrs): 372 Rx · 10,702 units · $4,708,469 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 Letairis — 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 Letairis. 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
$13.26M
Claims incl. refills
863
Beneficiaries
351
Spend / beneficiary
$37,765.57
Spend / claim
$15,360.04
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.
🛡
This drug has a REMS. A Risk Evaluation & Mitigation Strategy is an FDA-required safety program. It may require enrollment, counseling, or monitoring to manage a serious risk. See the boxed warning & full label below, and REMS@FDA ↗.

🔬 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 Letairis (this brand).

Top reported reactions

Dyspnoea19,138
Death11,350
Headache10,770
Pneumonia7,267
Diarrhoea7,105
Fatigue6,597
Dizziness6,553

Age at onset

Neonate7
Infant43
Child873
Adolescent709
Adult32,017
Elderly27,686

Reporter sex

124,133 reports
Male · 24%
Female · 76%
Unknown · 0%

Serious outcomes

Hospitalization52,454
Death17,006
Life-threatening1,139
Disabling666
Reports over time (by year) — tap or hover for the count & year
2024 2025 2026 5,133 1,418
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.

📦 Packaging — all sizes for this product

Package NDCDescription Marketing startStatus
61958-0801-01 30 TABLET, FILM COATED in 1 BOTTLE, PLASTIC (61958-0801-1) 2007-06-15 Active
61958-0801-02 3 BLISTER PACK in 1 CARTON (61958-0801-2) / 10 TABLET, FILM COATED in 1 BLISTER PACK 2007-06-15 Active
61958-0801-03 1 BLISTER PACK in 1 CARTON (61958-0801-3) / 10 TABLET, FILM COATED in 1 BLISTER PACK 2007-06-15 Active
61958-0801-04 1 BLISTER PACK in 1 CARTON (61958-0801-4) / 10 TABLET, FILM COATED in 1 BLISTER PACK 2007-06-15 Active
61958-0801-05 10 TABLET, FILM COATED in 1 BOTTLE, PLASTIC (61958-0801-5) 2007-06-15 Active
61958-0801-06 You're viewing this 10 TABLET, FILM COATED in 1 BOTTLE, PLASTIC (61958-0801-6) 2007-06-15 Active

This pack shows little to no recent Medicaid volume — the 30 tablets pack carries most fills. See all packs ↓

Pack size FAQ

What quantity is in NDC 61958-0801-06?
NDC 61958-0801-06 is a 10-count package — 10 tablet, film coated in 1 bottle, plastic.
What is the difference between NDC 61958-0801-06 and NDC 61958-0801-03?
Both are Letairis AMBRISENTAN 5 mg Tablet, Film Coated — the drug itself is identical. NDC 61958-0801-06 is the 10-count package, while NDC 61958-0801-03 is the 10 tablets package.
What NDC number is used to bill for this package of Letairis AMBRISENTAN 5 mg Tablet, Film Coated?
Bill NDC 61958-0801-06 — the 11-digit billing format is 61958080106. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

🧭 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 FDA registers it as 61958-0801-6, 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: 61958-0801-06, written without dashes as 61958080106. 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 61958-0801-06, the first segment (61958) is the labeler code FDA assigned to Gilead Sciences, Inc.; the middle segment (0801) 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 Gilead Sciences, 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 5 other package presentations of this same product, including 10 tablets (61958-0801-02), 10 tablets (61958-0801-03), 10 tablets (61958-0801-04). 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?
Gilead Sciences, 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.
🚨 Boxed Warning 🎯 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 📦 Storage and Handling 📋 Description 💬 Information for Patients 💬 Medication Guide
🚨 Boxed Warning 195 words ▾

WARNING: EMBRYO-FETAL TOXICITY Letairis is contraindicated for use during pregnancy because it may cause major birth defects if used by pregnant patients, based on studies in animals [see Contraindications (4.1) , Warnings and Precautions (5.1) , and Use in Specific Populations (8.1) ] . Therefore, for females of reproductive potential, exclude pregnancy before the initiation of treatment with Letairis. Advise use of effective contraception before initiation, during treatment, and for one month after treatment with Letairis [see Dosage and Administration (2.2) Contraindications (4.1) , Warnings and Precautions (5.1) , and Use in Specific Populations (8.1 , 8.3) ].

When pregnancy is detected, discontinue Letairis as soon as possible ( 5.1 ). WARNING: EMBRYO-FETAL TOXICITY See full prescribing information for complete boxed warning. Based on animal data Letairis may cause fetal harm if used during pregnancy ( 4.1 , 5.1 , 8.1 ).

Females of reproductive potential: Exclude pregnancy before the start of treatment. Use effective contraception prior to initiation of treatment, during treatment, and for one month after treatment with Letairis ( 2.2 , 4.1 , 5.1 , 8.1 , 8.3 ) When pregnancy is detected, discontinue Letairis as soon as possible ( 5.1 ).

🎯 Indications and Usage 166 words ▾

1 INDICATIONS AND USAGE Letairis is indicated for the treatment of pulmonary arterial hypertension (PAH) (WHO Group 1) in adult patients: To improve exercise ability and delay clinical worsening. In combination with tadalafil to reduce the risks of disease progression and hospitalization for worsening PAH, and to improve exercise ability [see Clinical Studies (14.2) ]. Studies establishing effectiveness included predominantly patients with WHO Functional Class II–III symptoms and etiologies of idiopathic or heritable PAH (60%) or PAH associated with connective tissue diseases (34%).

Letairis is an endothelin receptor antagonist indicated for the treatment of pulmonary arterial hypertension (PAH) (WHO Group 1) in adult patients: To improve exercise ability and delay clinical worsening. In combination with tadalafil to reduce the risks of disease progression and hospitalization for worsening PAH, and to improve exercise ability. Studies establishing effectiveness included trials predominantly in patients with WHO Functional Class II–III symptoms and etiologies of idiopathic or heritable PAH (60%) or PAH associated with connective tissue diseases (34%) ( 1 ).

⏱️ Dosage and Administration 127 words ▾

2 DOSAGE AND ADMINISTRATION Initiate treatment at 5 mg once daily ( 2.1 ). May be started with tadalafil ( 2.1 ). Titrate at 4-week intervals as needed and tolerated ( 2.1 ). Do not split, crush, or chew tablets ( 2.1 ).

2.1Adult Dosage Initiate treatment at 5 mg once daily, with or without tadalafil 20 mg once daily. At 4-week intervals, either the dose of Letairis or tadalafil can be increased, as needed and tolerated, to Letairis 10 mg or tadalafil 40 mg. Do not split, crush, or chew tablets.

2.2Pregnancy Testing in Females of Reproductive Potential Exclude pregnancy before initiating treatment with Letairis in females of reproductive potential [see Warnings and Precautions (5.1) , Use in Specific Populations (8.1 , 8.3) ].

💊 Dosage Forms and Strengths 66 words ▾

3 DOSAGE FORMS AND STRENGTHS 5 mg and 10 mg film - coated tablets for oral administration Each 5 mg tablet is square convex, pale pink, with “5” on one side and “GSI” on the other side. Each 10 mg tablet is oval convex, deep pink, with “10” on one side and “GSI” on the other side. Tablet: 5 mg and 10 mg ( 3 )

⛔ Contraindications 121 words ▾

4 CONTRAINDICATIONS Pregnancy ( 4.1 ) Idiopathic Pulmonary Fibrosis ( 4.2 )

4.1Pregnancy Letairis may cause fetal harm when administered to a pregnant female. Letairis is contraindicated in females who are pregnant. Letairis was consistently shown to have teratogenic effects when administered to animals.

If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus [see Dosage and Administration (2.2) , Warnings and Precautions (5.1) , and Use in Specific Populations (8.1) ] .

4.2Idiopathic Pulmonary Fibrosis Letairis is contraindicated in patients with Idiopathic Pulmonary Fibrosis (IPF), including IPF patients with pulmonary hypertension (WHO Group 3) [see Clinical Studies (14.4) ].

⚠️ Warnings and Cautions ~3 min read ▾

5 WARNINGS AND PRECAUTIONS Fluid retention may require intervention ( 5.2 ). If patients develop acute pulmonary edema during initiation of therapy with Letairis, consider underlying pulmonary veno-occlusive disease and discontinue treatment if necessary ( 5.3 ). Decreases in sperm count have been observed in patients taking endothelin receptor antagonists ( 5.4 ).

Decreases in hemoglobin have been observed within the first few weeks; measure hemoglobin at initiation, at 1 month, and periodically thereafter ( 5.5 ).

5.1Embryo-fetal Toxicity Based on data from animal reproduction studies, Letairis may cause fetal harm when administered during pregnancy and is contraindicated during pregnancy. The available human data for endothelin receptor antagonists do not establish the presence or absence of major birth defects related to the use of Letairis. Advise patients who can become pregnant of the potential risk to a fetus.

Obtain a pregnancy test prior to initiation of treatment with Letairis. Advise patients who can become pregnant to use effective contraception prior to initiation of treatment, during treatment, and for one month after discontinuation of treatment with Letairis. When pregnancy is detected, discontinue use as soon as possible [see Dosage and Administration (2.2) , and Use in Specific Populations (8.1 , 8.3) ] .

5.2Fluid Retention Peripheral edema is a known class effect of endothelin receptor antagonists, and is also a clinical consequence of PAH and worsening PAH. In the placebo-controlled studies, there was an increased incidence of peripheral edema in patients treated with doses of 5 or 10 mg Letairis compared to placebo [see Adverse Reactions (6.1) ] . Most edema was mild to moderate in severity.

In addition, there have been postmarketing reports of fluid retention in patients with pulmonary hypertension, occurring within weeks after starting Letairis. Patients required intervention with a diuretic, fluid management, or, in some cases, hospitalization for decompensating heart failure. If clinically significant fluid retention develops, with or without associated weight gain, further evaluation should be undertaken to determine the cause, such as Letairis or underlying heart failure, and the possible need for specific treatment or discontinuation of Letairis therapy.

Peripheral edema/fluid retention is more common with Letairis plus tadalafil than with Letairis or tadalafil alone.

5.3Pulmonary Edema with Pulmonary Veno-occlusive Disease (PVOD) If patients develop acute pulmonary edema during initiation of therapy with vasodilating agents such as Letairis, the possibility of PVOD should be considered, and if confirmed Letairis should be discontinued.

5.4Decreased Sperm Counts Decreased sperm counts have been observed in human and animal studies with another endothelin receptor antagonist and in animal fertility studies with ambrisentan. Letairis may have an adverse effect on spermatogenesis. Counsel patients about potential effects on fertility [see Use in Specific Populations (8.6) and Nonclinical Toxicology (13.1) ].

5.5Hematological Changes Decreases in hemoglobin concentration and hematocrit have followed administration of other endothelin receptor antagonists and were observed in clinical studies with Letairis. These decreases were observed within the first few weeks of treatment with Letairis, and stabilized thereafter. The mean decrease in hemoglobin from baseline to end of treatment for those patients receiving Letairis in the 12-week placebo-controlled studies was 0.8 g/dL.

Marked decreases in hemoglobin (>15% decrease from baseline resulting in a value below the lower limit of normal) were observed in 7% of all patients receiving Letairis (and 10% of patients receiving 10 mg) compared to 4% of patients receiving placebo. The cause of the decrease in hemoglobin is unknown, but it does not appear to result from hemorrhage or hemolysis. In the long-term open-label extension of the two pivotal clinica…

🤒 Adverse Reactions ~3 min read ▾

6 ADVERSE REACTIONS Clinically significant adverse reactions that appear in other sections of the labeling include: Embryo-fetal Toxicity [see Warnings and Precautions (5.1) , Use in Specific Populations (8.1) ] Fluid Retention [see Warnings and Precautions (5.2) ] Pulmonary Edema with PVOD [see Warnings and Precautions (5.3) ] Decreased Sperm Count [see Warnings and Precautions (5.4) ] Hematologic Changes [see Warnings and Precautions (5.5) ] Most common adverse reactions (>3% compared to placebo) are peripheral edema, nasal congestion, sinusitis, and flushing ( 6.1 ).

When used in combination with tadalafil, most common adverse reactions (>5% compared with either monotherapy) are peripheral edema, headache, nasal congestion, cough, anemia, dyspepsia, and bronchitis ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Gilead Sciences, Inc. at (1-800-445-3235, Option 3) 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. Safety data for Letairis are presented from two 12-week, placebo-controlled studies (ARIES-1 and ARIES-2) in patients with pulmonary arterial hypertension (PAH), and one randomized, double-blind, active-controlled trial in 605 patients with PAH (AMBITION) comparing Letairis plus tadalafil to Letairis or tadalafil alone.

The exposure to Letairis in these studies ranged from 1 day to 4 years (N=357 for at least 6 months and N=279 for at least 1 year). In ARIES-1 and ARIES-2, a total of 261 patients received Letairis at doses of 2.5, 5, or 10 mg once daily and 132 patients received placebo. The adverse reactions that occurred in >3% more patients receiving Letairis than receiving placebo are shown in Table 1.

Table 1 Adverse Reactions with Placebo-Adjusted Rates >3% in ARIES-1 and ARIES-2 Placebo (N=132) Letairis (N=261) Adverse Reaction n (%) n (%) Placebo-adjusted (%) Peripheral edema 14 (11) 45 (17) 6 Nasal congestion 2 (2) 15 (6) 4 Sinusitis 0 (0) 8 (3) 3 Flushing 1 (1) 10 (4) 3 Most adverse drug reactions were mild to moderate and only nasal congestion was dose-dependent. Few notable differences in the incidence of adverse reactions were observed for patients by age or sex. Peripheral edema was similar in younger patients (<65 years) receiving Letairis (14%; 29/205) or placebo (13%; 13/104), and was greater in elderly patients (≥65 years) receiving Letairis (29%; 16/56) compared to placebo (4%; 1/28).

The results of such subgroup analyses must be interpreted cautiously. The incidence of treatment discontinuations due to adverse events other than those related to PAH during the clinical trials in patients with PAH was similar for Letairis (2%; 5/261 patients) and placebo (2%; 3/132 patients). The incidence of patients with serious adverse events other than those related to PAH during the clinical trials in patients with PAH was similar for placebo (7%; 9/132 patients) and for Letairis (5%; 13/261 patients).

During 12-week controlled clinical trials, the incidence of aminotransferase elevations >3 × upper limit of normal (ULN) were 0% on Letairis and 2.3% on placebo. In practice, cases of hepatic injury should be carefully evaluated for cause. Combination Use with Tadalafil The mean exposure to Letairis + tadalafil in the AMBITION study was 78.7 weeks.

The adverse reactions that occurred in >5% more patients receiving Letairis + tadalafil than receiving Letairis or tadalafil monotherapy in AMBITION are shown in Table 2. Table 2 Adverse Reactions Reported More Commonly (>5%) on Letairis + Tadalafil than on Letairis or Tadalafil Monotherapy (ITT) in AMBITION Adverse Reactions Letairis + Tadalafil Combination Therapy (N=302) n (%) Letairis Monotherapy (N=152) n (%) Tadalafil Monotherapy (N=151) n (%) Peripheral edema 135…

🔄 Drug Interactions 58 words ▾

7 DRUG INTERACTIONS Multiple dose coadministration of ambrisentan and cyclosporine resulted in an approximately 2-fold increase in ambrisentan exposure in healthy volunteers; therefore, limit the dose of ambrisentan to 5 mg once daily when coadministered with cyclosporine [see Clinical Pharmacology (12.3) ] . Cyclosporine increases ambrisentan exposure; limit ambrisentan dose to 5 mg once daily ( 7 ).

👥 Use in Specific Populations ~3 min read ▾

8 USE IN SPECIFIC POPULATIONS Breastfeeding: Choose Letairis or breastfeeding ( 8.2 ). Not recommended in patients with moderate or severe hepatic impairment ( 8.7 ).

8.1Pregnancy Risk Summary Based on data from animal reproduction studies, Letairis may cause fetal harm, including birth defects and fetal death, when administered to a pregnant woman and is contraindicated during pregnancy. There are limited data on Letairis use in pregnant women. Available data from post-marketing reports and published literature over decades of use with endothelin receptor antagonists in the same class as Letairis have not identified an increased risk of major birth defects; however, these data are limited.

Methodological limitations of these postmarketing reports and published literature include lack of a control group; limited information regarding dose, duration, and timing of drug exposure; and missing data. These limitations preclude establishing a reliable estimate of the risk of adverse fetal and neonatal outcomes with maternal endothelin receptor antagonist use. In animal reproduction studies, Letairis was teratogenic in rats and rabbits at doses which resulted in exposures of 3.5 and 1.7 times, respectively, the human dose of 10 mg per day [see Animal Data ] .

If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, advise the patient of the potential hazard to a fetus [see Contraindications (4.1) , Warnings and Precautions (5.1) ] . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes.

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Data Animal Data Letairis was teratogenic at oral dosages of ≥15 mg/kg/day (AUC 51.7 h•µg/mL) in rats and ≥7 mg/kg/day (24.7 h•µg/mL) in rabbits; it was not studied at lower dosages. These dosages are of 3.5 and 1.7 times, respectively, the human dose of 10 mg per day (14.8 h•µg/mL) based on AUC.

In both species, there were abnormalities of the lower jaw and hard and soft palate, malformation of the heart and great vessels, and failure of formation of the thymus and thyroid. A preclinical study in rats has shown decreased survival of newborn pups (mid and high dosages) and effects on testicle size and fertility of pups (high dosage) following maternal treatment with ambrisentan from late gestation through weaning. The mid and high dosages were 51 ×, and 170 × (on a mg/m 2 body surface area basis) the maximum oral human dose of 10 mg and an average adult body weight of 70 kg.

These effects were absent at a maternal dosage 17 × the human dose based on mg/m 2 .

8.2Lactation Risk Summary It is not known whether ambrisentan is present in human milk. Because many drugs are present in human milk and because of the potential for serious adverse reactions in breastfed infants from Letairis, a decision should be made whether to discontinue breastfeeding or discontinue Letairis, taking into account the importance of the drug to the mother.

8.3Females and Males of Reproductive Potential Based on data from animal reproductive toxicity studies, ambrisentan may cause fetal harm, including birth defects and fetal death, when administered to a pregnant patient and is contraindicated during pregnancy [see Contraindications (4.1) , Use in Specific Populations (8.1) ] . Pregnancy Testing Verify that patients who can become pregnant are not pregnant prior to initiating ambrisentan. The patient should contact their physician immediately for pregnancy testing if onset of menses is delayed or pregnancy is suspected.

If the pregnancy test is positive, the physician and patient should discuss the risks to the pregnancy and the fetus. Contraception Patients who can become pregnant who are using ambrisentan should use effecti…

🤰 Pregnancy ~2 min read ▾

8.1Pregnancy Risk Summary Based on data from animal reproduction studies, Letairis may cause fetal harm, including birth defects and fetal death, when administered to a pregnant woman and is contraindicated during pregnancy. There are limited data on Letairis use in pregnant women. Available data from post-marketing reports and published literature over decades of use with endothelin receptor antagonists in the same class as Letairis have not identified an increased risk of major birth defects; however, these data are limited.

Methodological limitations of these postmarketing reports and published literature include lack of a control group; limited information regarding dose, duration, and timing of drug exposure; and missing data. These limitations preclude establishing a reliable estimate of the risk of adverse fetal and neonatal outcomes with maternal endothelin receptor antagonist use. In animal reproduction studies, Letairis was teratogenic in rats and rabbits at doses which resulted in exposures of 3.5 and 1.7 times, respectively, the human dose of 10 mg per day [see Animal Data ] .

If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, advise the patient of the potential hazard to a fetus [see Contraindications (4.1) , Warnings and Precautions (5.1) ] . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes.

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Data Animal Data Letairis was teratogenic at oral dosages of ≥15 mg/kg/day (AUC 51.7 h•µg/mL) in rats and ≥7 mg/kg/day (24.7 h•µg/mL) in rabbits; it was not studied at lower dosages. These dosages are of 3.5 and 1.7 times, respectively, the human dose of 10 mg per day (14.8 h•µg/mL) based on AUC.

In both species, there were abnormalities of the lower jaw and hard and soft palate, malformation of the heart and great vessels, and failure of formation of the thymus and thyroid. A preclinical study in rats has shown decreased survival of newborn pups (mid and high dosages) and effects on testicle size and fertility of pups (high dosage) following maternal treatment with ambrisentan from late gestation through weaning. The mid and high dosages were 51 ×, and 170 × (on a mg/m 2 body surface area basis) the maximum oral human dose of 10 mg and an average adult body weight of 70 kg.

These effects were absent at a maternal dosage 17 × the human dose based on mg/m 2 .

🧒 Pediatric Use 76 words ▾

8.4Pediatric Use Safety and effectiveness of Letairis in pediatric patients have not been established . Juvenile Animal Data In juvenile rats administered ambrisentan orally once daily during postnatal day 7 to 26, 36, or 62, a decrease in brain weight (−3% to −8%) with no morphologic or neurobehavioral changes occurred after breathing sounds, apnea, and hypoxia were observed, at exposures approximately 1.8 to 7.0 times human pediatric exposures at 10 mg, based on AUC .

🧓 Geriatric Use 64 words ▾

8.5Geriatric Use In the two placebo-controlled clinical studies of Letairis, 21% of patients were ≥65 years old and 5% were ≥75 years old. The elderly (age ≥65 years) showed less improvement in walk distances with Letairis than younger patients did, but the results of such subgroup analyses must be interpreted cautiously. Peripheral edema was more common in the elderly than in younger patients.

🆘 Overdosage 78 words ▾

10 OVERDOSAGE There is no experience with overdosage of Letairis. The highest single dose of Letairis administered to healthy volunteers was 100 mg, and the highest daily dose administered to patients with PAH was 10 mg once daily. In healthy volunteers, single doses of 50 mg and 100 mg (5 to 10 times the maximum recommended dose) were associated with headache, flushing, dizziness, nausea, and nasal congestion.

Massive overdosage could potentially result in hypotension that may require intervention.

🧬 Clinical Pharmacology ~3 min read ▾

12 CLINICAL PHARMACOLOGY

12.1Mechanism of Action Endothelin-1 (ET-1) is a potent autocrine and paracrine peptide. Two receptor subtypes, ET A and ET B , mediate the effects of ET-1 in the vascular smooth muscle and endothelium. The primary actions of ET A are vasoconstriction and cell proliferation, while the predominant actions of ET B are vasodilation, antiproliferation, and ET-1 clearance.

In patients with PAH, plasma ET-1 concentrations are increased as much as 10-fold and correlate with increased mean right atrial pressure and disease severity. ET-1 and ET-1 mRNA concentrations are increased as much as 9-fold in the lung tissue of patients with PAH, primarily in the endothelium of pulmonary arteries. These findings suggest that ET-1 may play a critical role in the pathogenesis and progression of PAH.

Ambrisentan is a high-affinity (K i =0.011 nM) ET A receptor antagonist with a high selectivity for the ET A versus ET B receptor (>4000-fold). The clinical impact of high selectivity for ET A is not known.

12.2Pharmacodynamics Cardiac Electrophysiology In a randomized, positive- and placebo-controlled, parallel-group study, healthy subjects received either Letairis 10 mg daily followed by a single dose of 40 mg, placebo followed by a single dose of moxifloxacin 400 mg, or placebo alone. Letairis 10 mg daily had no significant effect on the QTc interval. The 40 mg dose of Letairis increased mean QTc at t max by 5 ms with an upper 95% confidence limit of 9 ms.

For patients receiving Letairis 5–10 mg daily and not taking metabolic inhibitors, no significant QT prolongation is expected. N-terminal pro-B-type natriuretic peptide (NT-proBNP) In AMBITION [see Clinical Studies (14.2) ] , the decrease in NT-proBNP in patients on Letairis plus tadalafil was observed early (Week 4) and was sustained, with a reduction of 63% on Letairis plus tadalafil, 50% on Letairis alone, and 41% on tadalafil alone at Week 24.

12.3Pharmacokinetics The pharmacokinetics of ambrisentan (S-ambrisentan) in healthy subjects is dose proportional. The absolute bioavailability of ambrisentan is not known. Ambrisentan is absorbed with peak concentrations occurring approximately 2 hours after oral administration in healthy subjects and PAH patients.

Food does not affect its bioavailability. In vitro studies indicate that ambrisentan is a substrate of P-gp. Ambrisentan is highly bound to plasma proteins (99%).

The elimination of ambrisentan is predominantly by non-renal pathways, but the relative contributions of metabolism and biliary elimination have not been well characterized. In plasma, the AUC of 4-hydroxymethyl ambrisentan accounts for approximately 4% relative to parent ambrisentan AUC. The in vivo inversion of S-ambrisentan to R-ambrisentan is negligible.

The mean oral clearance of ambrisentan is 38 mL/min and 19 mL/min in healthy subjects and in PAH patients, respectively. Although ambrisentan has a 15-hour terminal half-life, the mean trough concentration of ambrisentan at steady-state is about 15% of the mean peak concentration and the accumulation factor is about 1.2 after long-term daily dosing, indicating that the effective half-life of ambrisentan is about 9 hours. Drug Interactions In Vitro Studies Studies with human liver tissue indicate that ambrisentan is metabolized by CYP3A, CYP2C19, and uridine 5'-diphosphate glucuronosyltransferases (UGTs) 1A9S, 2B7S, and 1A3S.

In vitro studies suggest that ambrisentan is a substrate of the Organic Anion Transporting Polypeptides OATP1B1 and OATP1B3, and P-glycoprotein (P-gp). Drug interactions might be expected because of these factors; however, a clinically relevant interaction has been demonstrated only with cyclosporine [see Drug Interactions (7) ] . In vitro studies found ambrisentan to have little to no inhibition of human hepatic transporters.

Ambrisentan demonstrated weak dose-dependent inhibition of OATP1B1, OATP1B3, and NTCP (IC 50 of 47 µM, 45 µM, and approximately 100 µM, respectively) and…

🧬 Mechanism of Action 162 words ▾

12.1Mechanism of Action Endothelin-1 (ET-1) is a potent autocrine and paracrine peptide. Two receptor subtypes, ET A and ET B , mediate the effects of ET-1 in the vascular smooth muscle and endothelium. The primary actions of ET A are vasoconstriction and cell proliferation, while the predominant actions of ET B are vasodilation, antiproliferation, and ET-1 clearance.

In patients with PAH, plasma ET-1 concentrations are increased as much as 10-fold and correlate with increased mean right atrial pressure and disease severity. ET-1 and ET-1 mRNA concentrations are increased as much as 9-fold in the lung tissue of patients with PAH, primarily in the endothelium of pulmonary arteries. These findings suggest that ET-1 may play a critical role in the pathogenesis and progression of PAH.

Ambrisentan is a high-affinity (K i =0.011 nM) ET A receptor antagonist with a high selectivity for the ET A versus ET B receptor (>4000-fold). The clinical impact of high selectivity for ET A is not known.

📦 How Supplied / Storage and Handling 159 words ▾

16 HOW SUPPLIED/STORAGE AND HANDLING Letairis film - coated tablets are supplied as follows: Tablet Strength Package Configuration NDC No. Description of Tablet; Debossed on Tablet; Size 5 mg 30 count blister 61958 - 0801 - 2 Square convex; pale pink; "5" on side 1 and "GSI" on side 2; 6.6 mm Square 30 count bottle 61958 - 0801 - 1 10 count blister 61958 - 0801 - 3 10 count bottle 61958 - 0801 - 5 10 mg 30 count blister 61958 - 0802 - 2 Oval convex; deep pink; "10" on side 1 and "GSI" on side 2; 9.8 mm × 4.9 mm Oval 30 count bottle 61958 - 0802 - 1 10 count blister 61958 - 0802 - 3 10 count bottle 61958 - 0802 - 5 Store at 25° C (77° F); excursions permitted to 15 – 30° C (59 – 86° F) [see USP controlled room temperature] .

Store Letairis in its original packaging.

📦 Storage and Handling 29 words ▾

Store at 25° C (77° F); excursions permitted to 15 – 30° C (59 – 86° F) [see USP controlled room temperature] . Store Letairis in its original packaging.

📋 Description 188 words ▾

11 DESCRIPTION Letairis contains ambrisentan, an endothelin receptor antagonist. The chemical name of ambrisentan is (+)-(2 S )-2-[(4,6-dimethylpyrimidin-2-yl)oxy]-3-methoxy-3,3-diphenylpropanoic acid. It has a molecular formula of C 22 H 22 N 2 O 4 and a molecular weight of 378.42 and has the following structural formula: Figure 1 Ambrisentan Structural Formula Ambrisentan is a white to off-white, crystalline solid.

It is a carboxylic acid with a pKa of 4.0. Ambrisentan is practically insoluble in water and in aqueous solutions at low pH. Solubility increases in aqueous solutions at higher pH.

In the solid state ambrisentan is very stable, is not hygroscopic, and is not light sensitive. Letairis is available as 5 mg and 10 mg film-coated tablets for once daily oral administration. The tablets include the following inactive ingredients: croscarmellose sodium, lactose monohydrate, magnesium stearate and microcrystalline cellulose.

The tablets are film-coated with a coating material containing FD&C Red #40 aluminum lake, lecithin, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide. Each square, pale pink Letairis tablet contains 5 mg of ambrisentan. Each oval, deep pink Letairis tablet contains 10 mg of ambrisentan.

Letairis tablets are unscored. Chemical Structure

💬 Information for Patients ~1 min read ▾

17 PATIENT COUNSELING INFORMATION Advise patients to read the FDA-approved patient labeling ( Medication Guide ). Embryo-fetal Toxicity Instruct patients on the risk of fetal harm when Letairis is used in pregnancy [see Warnings and Precautions (5.1) and Use in Specific Populations (8.1) ] . Instruct females of reproductive potential to immediately contact their physician if they suspect they may be pregnant.

Educate and counsel patients who can become pregnant about the need to use effective contraception prior to treatment with Letairis, during treatment, and for one month after treatment discontinuation [see Warnings and Precautions (5.1) and Use in Specific Populations (8.1 , 8.3) ] . Patients who can become pregnant should have a negative pregnancy test prior to treatment with Letairis [see Dosage and Administration (2.2) , Contraindications (4.1) , Warnings and Precautions (5.1) , Use in Specific Populations (8.1 , 8.3) ] .

Counsel patients who can become pregnant about pregnancy planning and prevention, including emergency contraception, or designate counseling by another healthcare provider trained in contraceptive counseling [see Boxed Warning ] . Hepatic Effects Advise patients of the symptoms of potential liver injury and instruct them to report any of these symptoms to their physician. Hematological Change Advise patients of the importance of hemoglobin testing.

Other Risks Associated with Letairis Instruct patients that the risks associated with Letairis also include the following: Decreases in sperm count Fluid overload Administration Advise patients not to split, crush, or chew tablets.

💬 Medication Guide ~3 min read ▾

This Medication Guide has been approved by the U.S. Food and Drug Administration. Revised April 2025 Medication Guide Letairis ® (le-TAIR-is) (ambrisentan) tablets Read this Medication Guide before you start taking Letairis and each time you get a refill.

There may be new information. This Medication Guide does not take the place of talking with your doctor about your medical condition or your treatment. What is the most important information I should know about Letairis?

Serious birth defects. Letairis can cause serious birth defects if taken during pregnancy. Females should not be pregnant when they start taking Letairis or become pregnant during treatment with Letairis.

Females who are able to get pregnant should have a negative pregnancy test before beginning treatment with Letairis. Talk to your doctor about your menstrual cycle. Your doctor will decide when to do a pregnancy test, and will order a pregnancy test for you depending on your menstrual cycle.

Females who are able to get pregnant are females who: have entered puberty, even if they have not started their menstrual period, and have a uterus, and have not gone through menopause. Menopause means that you have not had a menstrual period for at least 12 months for natural reasons, or that you have had your ovaries removed. Females who are not able to get pregnant are females who: have not yet entered puberty, or do not have a uterus, or have gone through menopause.

Menopause means that you have not had a menstrual period for at least 12 months for natural reasons, or that you have had your ovaries removed, or who are infertile for any other medical reason and this infertility is permanent and cannot be reversed Females who are able to get pregnant should use effective contraception before beginning Letairis, during treatment with Letairis, and for one month after stopping Letairis because the medicine may still be in the body. Talk with your doctor or gynecologist (a doctor who specializes in female reproduction) to find out about options for acceptable forms of birth control that you may use to prevent pregnancy during treatment with Letairis.

If you decide that you want to change the form of birth control that you use, talk with your doctor or gynecologist to be sure that you choose another acceptable form of birth control. Do not have unprotected sex. Talk to your doctor or pharmacist right away if you have unprotected sex or if you think your birth control has failed.

Your doctor may tell you to use emergency birth control. Tell your doctor right away if you miss a menstrual period or think you may be pregnant for any reason. If you are the parent or caregiver of a female child who started taking Letairis before reaching puberty, you should check your child regularly to see if she is developing signs of puberty.

Tell your doctor right away if you notice that she is developing breast buds or pubic hair. Your doctor should decide if your child has reached puberty . Your child may reach puberty before having her first menstrual period.

What is Letairis? Letairis is a prescription medicine used to treat pulmonary arterial hypertension (PAH), which is high blood pressure in the arteries of your lungs. Letairis can improve your ability to exercise and it can help slow down the worsening of your physical condition and symptoms.

When taken with tadalafil, Letairis is used to reduce the risk of your disease progressing, to reduce the risk of hospitalization due to worsening pulmonary arterial hypertension (PAH), and to improve your ability to exercise. It is not known if Letairis is safe and effective in children. Who should not take Letairis?

Do not take Letairis if: you are pregnant, plan to become pregnant, or become pregnant during treatment with Letairis. Letairis can cause serious birth defects. (See “ What is the most important information I should know about Letairis? ” ) you have a condition called Idiopathic Pulmonary Fibrosis (IPF) What should I tell my doctor…

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.