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Warfarin

Warfarin is a blood thinner (vitamin K antagonist) used to prevent and treat dangerous blood clots, including clots in the veins and lungs, clots linked to atrial fibrillation or heart valve replacement, and clots after a heart attack.

Brand names CoumadinJantoven
Drug classes Vitamin K Antagonist
Rx Form 1
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Jul 10, 2026 Content updated Oct 2, 2026
🧬 Where this information comes from Click to expand

The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 82 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →

✓No current FDA shortage listed · checked Oct 5, 2026
Warfarin at a glance The quick version — the full detail is in the Patient Information Guide below.
Dr. Brian Staiger, PharmD, BCPS
The Pharmacist’s Take By · Clinical pharmacist · Written

Warfarin is a decades-old blood thinner, available as a generic, that slows clotting by blocking vitamin K. It prevents and treats clots in the veins and lungs and clots tied to atrial fibrillation, heart valve replacement or a heart attack, and it remains the standard choice for mechanical heart valves. Most people feel nothing day to day beyond easier bruising and small cuts that bleed longer. The boxed warning covers major or even fatal bleeding, so get help fast for black or bloody stools, blood in urine or a head injury. Regular INR blood tests, which measure how slowly your blood clots, keep the dose in a safe range.

Clinical pearls

  • Eat green leafy vegetables in steady amounts rather than avoiding them, since sudden changes in vitamin K swing your INR.
  • Tell every prescriber and dentist you take warfarin, because starting or stopping an antibiotic or antifungal usually needs an extra INR check.
  • Skip ibuprofen, naproxen, and garlic or ginkgo supplements, which add to bleeding, while St. John's wort can weaken warfarin.
  • Warfarin can cause birth defects, so use effective contraception during treatment and for at least a month after stopping.
How we write & review this content — our editorial policy →
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾

Warfarin can cause major or even fatal bleeding. Regular INR blood tests are required for everyone taking it. Other medicines, diet changes and other factors can change your INR.

Learn how to lower your bleeding risk and report any signs of bleeding to your doctor right away. These include blood in urine or stool, heavy menstrual bleeding, unusual bruising, and cuts that won't stop oozing.

Read the full warning on DailyMed →
How you get itPrescription only
Comes asTablet
Earliest FDA record1954
Companies listing it with the FDA18
FDA label last updatedMay 29, 2026
FDA’s strongest warning (boxed)Yes, read the warning

Patient information guide A plain-language walkthrough of Warfarin, written from its FDA label.

What Warfarin is used for

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Warfarin is a vitamin K antagonist (blood thinner) used to prevent and treat harmful clots.

  • Prevention and treatment of venous thrombosis (clots in the veins) and pulmonary embolism (clots in the lungs), for Warfarin Sodium tablets and Jantoven.
  • Prevention and treatment of clot-related complications of atrial fibrillation and/or heart valve replacement, for Warfarin Sodium tablets and Jantoven.
  • Lower risk of death, repeat heart attack, and clot events like stroke after a heart attack, for Warfarin Sodium tablets and Jantoven.

Warfarin does not directly act on a clot that already exists and does not reverse tissue damage from poor blood flow.

How Warfarin works

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Warfarin blocks an enzyme (VKORC1) that recycles vitamin K. Your body needs vitamin K to make clotting factors II, VII, IX and X, and the anticoagulant proteins C and S. With less active vitamin K, fewer working clotting factors are made, so blood clots more slowly.

Warfarin dosage

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Warfarin tablets are taken by mouth. The dose is different for every person and is adjusted based on your INR (a blood test that shows how long your blood takes to clot).

  • INR is checked daily when starting until stable, then every 1 to 4 weeks.
  • Treatment length depends on the condition. For some clots it is about 3 months, and for others it is long-term.
  • Keep a consistent amount of vitamin K in your diet.

Follow your prescriber's directions and the label exactly.

Dosing details from the FDA-approved label

From the Warfarin prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.

  • Initial dose when CYP2C9 and VKORC1 genotypes are not known
    • Usually 2 to 5 mg once daily
    • Typical maintenance doses are 2 to 10 mg once daily
    • Consider lower initial and maintenance doses for elderly and/or debilitated patients and in Asian patients
  • Venous Thromboembolism (including DVT and PE)
    • Adjust the warfarin dose to maintain a target INR of 2.5 (INR range, 2 to 3) for all treatment durations
    • 3 months for DVT or PE secondary to a transient (reversible) risk factor
    • At least 3 months for unprovoked DVT or PE
    • Long-term treatment for two episodes of unprovoked DVT or PE
    • After 3 months, evaluate the risk-benefit ratio of long-term treatment
  • Atrial Fibrillation (non-valvular)
    • Anticoagulate with warfarin to target INR of 2.5 (range, 2 to 3)
    • Long-term anticoagulation is recommended for persistent or paroxysmal AF at high or intermediate risk of stroke
  • AF with mitral stenosis
    • Long-term anticoagulation with warfarin is recommended
  • AF with prosthetic heart valves
    • Long-term anticoagulation with warfarin is recommended
    • The target INR may be increased and aspirin added depending on valve type and position, and on patient factors
  • Bileaflet mechanical valve or Medtronic Hall tilting disk valve in the aortic position (sinus rhythm, no left atrial enlargement)
    • Warfarin to a target INR of 2.5 (range, 2 to 3)
  • Tilting disk valves and bileaflet mechanical valves in the mitral position; caged ball or caged disk valves
    • Warfarin to a target INR of 3 (range, 2.5 to 3.5)
  • Bioprosthetic valve in the mitral position
    • Warfarin to a target INR of 2.5 (range, 2 to 3) for the first 3 months after valve insertion
    • If additional risk factors for thromboembolism are present, a target INR of 2.5 (range 2 to 3) is recommended
  • Post-Myocardial Infarction (high-risk patients)
    • Combined moderate-intensity (INR, 2 to 3) warfarin plus low-dose aspirin (≤ 100 mg/day) for at least 3 months after the MI
  • Recurrent systemic embolism and other indications
    • A moderate dose regimen (INR 2 to 3) may be used
    • Not fully evaluated by clinical trials in these patients
Read the label’s full dosing text

2 DOSAGE AND ADMINISTRATION Individualize dosing regimen for each patient, and adjust based on INR response. (2.1, 2.2) Knowledge of genotype can inform initial dose selection. (2.3) Monitoring: Obtain daily INR determinations upon initiation until stable in the therapeutic range. Obtain subsequent INR determinations every 1 to 4 weeks. (2.4) Review conversion instructions from other anticoagulants. ( 2.8 ) 2.1 Individualized Dosing The dosage and administration of warfarin sodium tablets must be individualized for each patient according to the patient’s International Normalized Ratio (INR) response to the drug. Adjust the dose based on the patient’s INR and the condition being treated. Consult the latest evidence-based clinical practice guidelines regarding the duration and intensity of anticoagulation for the indicated conditions. 2.2 Recommended Target INR Ranges and Durations for Individual Indications An INR of greater than 4.0 appears to provide no additional therapeutic benefit in most patients and is associated with a higher risk of bleeding. Venous Thromboembolism (including deep venous thrombosis [DVT] and PE) Adjust the warfarin dose to maintain a target INR of 2.5 (INR range, 2.0 to 3.0) for all treatment durations. The duration of treatment is based on the indication as follows: For patients with a DVT or PE secondary to a transient (reversible) risk factor, treatment with warfarin for 3 months is recommended. For patients with an unprovoked DVT or PE, treatment with warfarin is recommended for at least 3 months. After 3 months of therapy, evaluate the risk-benefit ratio of long-term treatment for the individual patient. For patients with two episodes of unprovoked DVT or PE, long-term treatment with warfarin is recommended. For a patient receiving long-term anticoagulant treatment, periodically reassess the risk-benefit ratio of continuing such treatment in the individual patient. Atrial Fibrillation In patients with non-valvular AF, anticoagulate with warfarin to target INR of 2.5 (range, 2.0 to 3.0).

Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →

Warfarin side effects

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The most common side effect is bleeding, which can be serious. Other reported effects include:

Common side effects

  • Bleeding (the most common side effect)
  • Nausea or vomiting
  • Diarrhea
  • Abdominal pain, gas or bloating
  • Changes in taste
  • Rash or itching
  • Hair loss
  • Chills

When to get medical help

  • Call your doctor right away or get emergency help for any signs of bleeding, such as blood in your stool or urine, black stools, or heavy menstrual bleeding.
  • Report unusual bruising, tiny red or purple spots on the skin, or cuts that keep oozing.
  • Seek help for skin or tissue changes such as pain, discoloration or sores, which may signal tissue death (necrosis) or gangrene.
  • Seek help for signs of an allergic reaction, such as hives or trouble breathing.
  • Tell your doctor about any serious fall or injury, especially to the head.
  • Report signs of liver problems or kidney problems.

Get help right away for signs of bleeding, skin or tissue damage, or allergic reactions such as hives.

Warfarin warnings and precautions

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  • Bleeding can be major or fatal, and is most likely in the first month.
  • Higher risk with INR above 4, age 65 or older, past stomach or intestinal bleeding, high blood pressure, stroke-related disease, anemia, cancer, trauma, and kidney problems.
  • Tissue necrosis or gangrene, calciphylaxis, acute kidney injury and cholesterol microemboli are uncommon but serious.
  • Starting warfarin during heparin-induced thrombocytopenia has led to amputation and death.
  • Pregnancy can lead to fetal harm.

Warfarin interactions

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Many medicines, herbals and foods can change how warfarin works, so INR needs closer checks when anything changes.

  • Blood thinners, aspirin and other antiplatelets: more bleeding.
  • NSAIDs such as ibuprofen and naproxen: more bleeding.
  • SSRI and SNRI antidepressants: more bleeding.
  • Antibiotics and antifungals: INR can shift.
  • Drugs that block or speed up liver enzymes (CYP2C9, 1A2, 3A4): can raise or lower INR.
  • Garlic and ginkgo: more bleeding. St. John's wort, ginseng and coenzyme Q10: may weaken warfarin.
  • Vitamin K in food: keep your intake steady.

Interactions listed in the FDA-approved label

From the Warfarin prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.

  • CYP2C9, 1A2, and/or 3A4 inhibitors (e.g., amiodarone, fluconazole, metronidazole, ciprofloxacin, ketoconazole): Have the potential to increase the effect (increase INR) of warfarin by increasing the exposure of warfarin. Closely monitor INR if a concomitant drug is a CYP2C9, 1A2, and/or 3A4 inhibitor or inducer.
  • CYP2C9, 1A2, and/or 3A4 inducers (e.g., rifampin, carbamazepine, phenobarbital, phenytoin): Have the potential to decrease the effect (decrease INR) of warfarin by decreasing the exposure of warfarin. Closely monitor INR if a concomitant drug is a CYP2C9, 1A2, and/or 3A4 inhibitor or inducer.
  • Anticoagulants (e.g., argatroban, dabigatran, heparin): Bleeding risk is increased when used concomitantly with warfarin. Closely monitor patients receiving any such drug with warfarin.
  • Antiplatelet agents (e.g., aspirin, clopidogrel, cilostazol): Bleeding risk is increased when used concomitantly with warfarin. Closely monitor patients receiving any such drug with warfarin.
  • Nonsteroidal anti-inflammatory agents (e.g., ibuprofen, naproxen, celecoxib): Bleeding risk is increased when used concomitantly with warfarin. Closely monitor patients receiving any such drug with warfarin.
  • Serotonin reuptake inhibitors (e.g., sertraline, fluoxetine, paroxetine): Bleeding risk is increased when used concomitantly with warfarin. Closely monitor patients receiving any such drug with warfarin.
  • Antibiotics and antifungals: There have been reports of changes in INR, but clinical pharmacokinetic studies have not shown consistent effects on plasma concentrations of warfarin. Closely monitor INR when starting or stopping any antibiotic or antifungal.
  • Botanicals that may cause bleeding (e.g., garlic and Ginkgo biloba): May have anticoagulant, antiplatelet, and/or fibrinolytic properties, expected to be additive to the anticoagulant effects of warfarin. More frequent INR monitoring should be performed when starting or stopping botanicals.
  • Botanicals that may decrease warfarin effect (e.g., co-enzyme Q10, St. John's wort, ginseng): Some botanicals may decrease the effects of warfarin sodium. More frequent INR monitoring should be performed when starting or stopping botanicals.
  • Vitamin K in food: The amount of vitamin K in food may affect therapy with warfarin. Eat a normal, balanced diet maintaining a consistent amount of vitamin K; avoid drastic changes in dietary habits, such as eating large amounts of green leafy vegetables.
Read the label’s full interactions text

7 DRUG INTERACTIONS • Concomitant use of drugs that increase bleeding risk, antibiotics, antifungals, botanical (herbal) products, and inhibitors and inducers of CYP2C9, 1A2, or 3A4. (7) • Consult labeling of all concurrently used drugs for complete information about interactions with warfarin sodium or increased risks for bleeding. (7) 7.1 General Information Drugs may interact with warfarin sodium through pharmacodynamic or pharmacokinetic mechanisms. Pharmacodynamic mechanisms for drug interactions with warfarin sodium are synergism (impaired hemostasis, reduced clotting factor synthesis), competitive antagonism (vitamin K), and alteration of the physiologic control loop for vitamin K metabolism (hereditary resistance). Pharmacokinetic mechanisms for drug interactions with warfarin sodium are mainly enzyme induction, enzyme inhibition, and reduced plasma protein binding. It is important to note that some drugs may interact by more than one mechanism. More frequent INR monitoring should be performed when starting or stopping other drugs, including botanicals, or when changing dosages of other drugs, including drugs intended for short-term use (e.g., antibiotics, antifungals, corticosteroids) [see Boxed Warning ]. Consult the labeling of all concurrently used drugs to obtain further information about interactions with warfarin sodium or adverse reactions pertaining to bleeding. 7.2 CYP450 Interactions CYP450 isozymes involved in the metabolism of warfarin include CYP2C9, 2C19, 2C8, 2C18, 1A2, and 3A4. The more potent warfarin S -enantiomer is metabolized by CYP2C9 while the R -enantiomer is metabolized by CYP1A2 and 3A4. • Inhibitors of CYP2C9, 1A2, and/or 3A4 have the potential to increase the effect (increase INR) of warfarin by increasing the exposure of warfarin. • Inducers of CYP2C9, 1A2, and/or 3A4 have the potential to decrease the effect (decrease INR) of warfarin by decreasing the exposure of warfarin.

Excerpted — the section continues on the label. Read the full Drug Interactions section on DailyMed →

Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.

🌿361 supplements and herbs with documented Warfarin interactions, ranked by severity Check Warfarin against a supplement or herb →

Before taking Warfarin

▾
  • Pregnancy: not for use except in some women with mechanical heart valves.
  • Use effective contraception during treatment and for at least 1 month after the last dose.
  • Breastfeeding: watch the infant for bruising or bleeding.
  • Active bleeding, bleeding disorders, or recent or planned eye or brain surgery.
  • Malignant hypertension or allergy to warfarin.
  • Spinal puncture or major regional anesthesia.
  • Kidney or liver impairment: more frequent monitoring.
  • Older adults: often need lower doses and closer bleeding checks.
  • Children: optimum dosing and safety are unknown, and injury-risk activities should be avoided.

Warfarin overdose

▾

Too much warfarin causes excess bleeding. Signs include blood in stool or urine, excessive menstrual bleeding, black stools, tiny red spots on the skin, excessive bruising, or oozing from small wounds. Treatment depends on your INR and whether you are bleeding. It may include stopping warfarin and giving vitamin K, and in urgent cases blood products.

What Warfarin does in the body

▾

Warfarin's blood-thinning effect generally starts within 24 hours. The peak effect may take 72 to 96 hours. A single dose lasts 2 to 5 days. Effects can build up with daily dosing as they overlap.

How your body processes Warfarin

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Warfarin is almost completely absorbed after you swallow it, with peak levels within about 4 hours. It is about 99% bound to proteins in the blood. The liver breaks it down, mainly using the CYP2C9 enzyme, and the effective half-life averages about 40 hours. Most of the dose leaves in urine as metabolites.

How to store Warfarin

▾

Protect from light and moisture. Store at 20° to 25°C (68° to 77°F) . Dispense in a tight, light-resistant container as defined in the USP.

Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

361

Supplements & herbs that interact with Warfarin

361 supplements and herbal products have documented interactions with Warfarin in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.

Severity mix
  • Major · 16
  • Moderate · 301
  • Minor · 44
ACTIVATED CHARCOAL Major ALFALFA Major AMERICAN GINSENG Major BEER Major CANNABIS Major DANSHEN Major DONG QUAI Major FASTING Major +353 more
Every supplement checked against Warfarin — ranked by severity The full interaction hub: 16 major · 301 moderate · 44 minor · every one linked to its full report. Check Warfarin against your exact supplements

Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.

Warfarin: pharmacist answers to common questions

Quick, plain-English answers to the questions patients ask most about Warfarin — the kind of thing our pharmacy team would talk through with you at the counter.

What is warfarin for?

▾
Warfarin helps prevent and treat harmful blood clots. That includes clots in the veins and lungs, clots linked to atrial fibrillation or heart valve replacement, and clots after a heart attack. It won't dissolve an existing clot, but it helps keep it from growing.

Why do I need so many blood tests?

▾
Your INR tells us how well your blood is clotting. Your dose is adjusted based on it. Expect checks daily at the start, then about every 1 to 4 weeks. Please don't skip them, because bleeding is the biggest risk.

Does what I eat matter?

▾
Yes. Vitamin K in food can affect warfarin. Eat a normal, balanced diet with a steady amount of vitamin K, and avoid sudden big changes like eating lots of leafy greens. Grapefruit juice and some herbals can also interact.

What should I tell my doctor or pharmacist about other medicines?

▾
Tell us about everything, including over-the-counter pain relievers like ibuprofen or naproxen, aspirin, antidepressants, antibiotics, antifungals and herbals like ginkgo, garlic or St. John's wort. Many of these raise bleeding risk or change your INR. Check with us before starting or stopping anything.

What side effects should I call about?

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Call right away for blood in your urine or stool, black stools, heavy periods, unusual bruising, or cuts that won't stop oozing. Also report painful skin changes or signs of an allergic reaction. Milder things like nausea, gas or rash are less urgent, but mention them.

Can I take warfarin if I'm pregnant?

▾
Generally no. Warfarin can cause birth defects and fetal bleeding. The exception is some women with mechanical heart valves, where your doctor weighs the risks. If you could become pregnant, use effective contraception and tell your doctor right away if you become pregnant.

Is Warfarin available over the counter?

▾
No. Warfarin is a prescription medicine: every Warfarin product listed with the FDA is prescription only, so it is not sold over the counter. Your prescriber decides whether it is appropriate for you, and your pharmacist dispenses it.

When was Warfarin first available?

▾
The earliest FDA record we hold for Warfarin is from 1954: its first approval in Drugs@FDA or its earliest product listing in the NDC Directory, whichever is older. Many older medicines were in use before their first formal FDA approval, so this is the earliest date on record, not necessarily when Warfarin was first used.

Who makes Warfarin?

▾
18 companies currently list Warfarin products in the FDA's NDC Directory, including Remedyrepack Inc., Aphena Pharma Solutions - Tennessee, LLC, Golden State Medical Supply, Inc.. That count includes repackagers and distributors as well as manufacturers (companies that sell only the raw ingredient are not counted), so fewer companies actually make it; the label on your bottle names the one that supplied yours.

Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

More about Warfarin on HelloPharmacist

📊Warfarin supplement interactions361 checked — ranked by severity 🌿Drug & Supplement CheckerWarfarin vs. vitamins & herbs 💬Ask a PharmacistFree answer, usually < 24h 🔎NDC & pricing lookupFind Warfarin NDCs & costs 🅰️Browse Drugs A–ZLook up any medication
Detailed data & references for Warfarin Forms & strengths, pricing, billing codes, manufacturers, safety reports and sourcing — the data behind the page. Most people can stop here. Each section below opens on a tap.

Warfarin forms and strengths (how it comes)

Warfarin is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.

Tablet

By mouth
Brands Jantoven
How this form is used
What it may be used for
  • Warfarin Sodium tablets are used to prevent and treat venous thrombosis and pulmonary embolism.
  • Jantoven is used to prevent and treat venous thrombosis and pulmonary embolism.
  • Warfarin Sodium tablets and Jantoven are used for clot complications of atrial fibrillation and/or heart valve replacement.
  • Warfarin Sodium tablets and Jantoven are used to reduce death, repeat heart attack and stroke risk after a heart attack.
Important instructions
  • Warfarin Sodium tablets are dosed individually and adjusted based on INR results.
  • Jantoven is dosed individually and adjusted based on INR results.
  • For both Warfarin Sodium tablets and Jantoven, INR is checked daily at the start until stable, then every 1 to 4 weeks.
  • For both products, a patient's genotype can help guide the starting dose.
Available strengths 9 strengths
1 mg 2 mg 2.5 mg 3 mg 4 mg 5 mg
Show 3 more strengths Show fewer strengths
6 mg 7.5 mg 10 mg
340 FDA-listed product records ⓘ

Warfarin on the U.S. market: products, makers and brands

How Warfarin appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.

18 companies list 149 Warfarin product records with the FDA, mostly as tablet; the earliest marketing or approval year on record is 1954. Brand names on the directory include Coumadin, Jantoven; the rest are generics.

1
Dose forms ⓘ
18
Labelers (makers, repackagers, distributors)
2
Brand names
149
FDA-listed product records ⓘ
1954
Earliest FDA record ⓘ

Also listed with the FDA, not a patient dose form: Powder (6) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.

Remedyrepack Inc.16%
Aphena Pharma Solutions - Tennessee, LLC10%
Golden State Medical Supply, Inc.10%
A-S Medication Solutions9%
Bryant Ranch Prepack9%
Amneal Pharmaceuticals LLC6%
Other makers39%

Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

How widely Warfarin is used (Medicaid data)

A general measure of how commonly Warfarin is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.

Think of this as a proxy for how widely Warfarin is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.

433,961
Medicaid prescriptions filled (Q1–Q4 2025)
$4.8M gross Medicaid reimbursement (before mandatory rebates — net cost is lower)

How commonly is Warfarin prescribed? Of the 1,601 medications we measure, Warfarin ranks #281 by Medicaid prescriptions — more than 82% of them.

Where Warfarin ranks among the drugs we measure · Q1–Q4 2025 · neighbors ±5
Total prescriptions — #281 of 1,601
#276 Fentanyl 440,395 Rx #277 Formoterol / Mometason... 440,187 Rx #278 Ziprasidone 438,206 Rx #279 Ciclopirox Topical 437,507 Rx #280 Diltiazem 435,096 Rx #281 Warfarin 433,961 Rx #282 Acetaminophen, Butalbi... 425,589 Rx #283 Varenicline 417,684 Rx #284 Human Insulin Injectio... 414,373 Rx #285 Loperamide 409,237 Rx #286 Tacrolimus Topical 408,485 Rx

Utilization by Warfarin product

Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.

The 5 mg oral tablet is the most-dispensed Warfarin product — about 36% of these Medicaid prescriptions.

warfarin sodium 5 MG Oral Tablet Most dispensed

156,200 Medicaid prescriptions (Q1–Q4 2025) 36% of Warfarin prescriptions shown $1.7M gross reimbursement (before rebates) ≈ $11 per prescription (gross)

Summed across the 10 of 165 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 855332

warfarin sodium 1 MG Oral Tablet

50,519 Medicaid prescriptions (Q1–Q4 2025) 12% of Warfarin prescriptions shown $594,531 gross reimbursement (before rebates) ≈ $12 per prescription (gross)

Summed across the 8 of 75 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 855288

warfarin sodium 4 MG Oral Tablet

41,243 Medicaid prescriptions (Q1–Q4 2025) 10% of Warfarin prescriptions shown $425,918 gross reimbursement (before rebates) ≈ $10 per prescription (gross)

Summed across the 8 of 68 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 855324

warfarin sodium 2 MG Oral Tablet

37,061 Medicaid prescriptions (Q1–Q4 2025) 9% of Warfarin prescriptions shown $460,199 gross reimbursement (before rebates) ≈ $12 per prescription (gross)

Summed across the 9 of 97 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 855302

warfarin sodium 3 MG Oral Tablet

35,542 Medicaid prescriptions (Q1–Q4 2025) 8% of Warfarin prescriptions shown $370,226 gross reimbursement (before rebates) ≈ $10 per prescription (gross)

Summed across the 6 of 66 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 855318

warfarin sodium 2.5 MG Oral Tablet

32,553 Medicaid prescriptions (Q1–Q4 2025) 8% of Warfarin prescriptions shown $370,762 gross reimbursement (before rebates) ≈ $11 per prescription (gross)

Summed across the 10 of 92 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 855312

warfarin sodium 7.5 MG Oral Tablet

28,330 Medicaid prescriptions (Q1–Q4 2025) 7% of Warfarin prescriptions shown $274,284 gross reimbursement (before rebates) ≈ $9.68 per prescription (gross)

Summed across the 4 of 45 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 855344

warfarin sodium 10 MG Oral Tablet

27,200 Medicaid prescriptions (Q1–Q4 2025) 6% of Warfarin prescriptions shown $280,755 gross reimbursement (before rebates) ≈ $10 per prescription (gross)

Summed across the 5 of 49 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 855296

warfarin sodium 6 MG Oral Tablet

25,313 Medicaid prescriptions (Q1–Q4 2025) 6% of Warfarin prescriptions shown $262,859 gross reimbursement (before rebates) ≈ $10 per prescription (gross)

Summed across the 5 of 34 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 855338

Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.

Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Warfarin, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 65 of 691 listed Warfarin NDCs with Medicaid activity.

Compare Warfarin products

A representative set of FDA-listed product records for Warfarin — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)

Showing 95 of 149 products — FDA National Drug Code Directory. See every product, package size and price: browse all 149 Warfarin NDCs →

Warfarin recall history

A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.

The FDA’s enforcement reports list one Warfarin recall since July 2021, covering 2 product listings. It is no longer listed as ongoing. A recall names specific lots from one company, so check the lot number on your own bottle rather than assuming every product is affected; your pharmacist can check whether your supply came from an affected lot.

Class II Jan 26, 2022 · Terminated · CARDINAL HEALTHCARE
CGMP Deviations: Products were exposed to temperatures outside of the products labeled storage conditions.
  • Warfarin Sodium Tablets, USP, 5 mg, 100 Tablets per bottle, Rx Only, Manufactured for: Teva Pharmaceuticals, Parsippany, NJ 07054. NDC: 0093-1721-01 Lots: Batch 2323041 FDA record D-0201-2024 →
  • Warfarin Sodium Tablets, USP, 2.5 mg, 100 Tablets per bottle, Rx only, Manufactured For: Teva Pharmaceuticals, Parsippany, NJ 07054. NDC: 0093-1714-01 Lots: Batch 2169041 FDA record D-0200-2024 →

Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.

RxNorm Concept Web — From Ingredient to Every Form and Strength

This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.

Ingredient (IN) Warfarin RxCUI 11289 1 dose form · 10 strengths

Look up RxCUI 11289 in the RxCUI Atlas →

RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.

💵 What Warfarin costs pharmacies (NADAC benchmark)

The national average invoice price pharmacies pay for the drug itself, from CMS's NADAC survey (data as of Sep 30, 2026). This is a supply-cost benchmark — not a retail price and not what you'd pay at the counter.

FormStrengthPharmacy acquisition benchmark
Tablet · Oral 5 mg $0.089 per tablet NDC details & price history
Tablet · Oral 2.5 mg $0.096 per tablet NDC details & price history
Tablet · Oral 2 mg $0.093 per tablet NDC details & price history
Tablet · Oral 4 mg $0.096 per tablet NDC details & price history
Tablet · Oral 1 mg $0.099 per tablet NDC details & price history
Tablet · Oral 3 mg $0.099 per tablet NDC details & price history
Tablet · Oral 10 mg $0.106 per tablet NDC details & price history
Tablet · Oral 7.5 mg $0.089 per tablet NDC details & price history
Why show this? Your out-of-pocket cost depends on insurance, pharmacy markup, and discounts — but the acquisition benchmark tells you whether the medication itself is inexpensive or costly, which strengths cost more per dose, and whether a cash-price quote is in a reasonable range. Each row links to the NDC-level record with its full price history.

Source: CMS National Average Drug Acquisition Cost (NADAC), a survey of retail pharmacy invoice prices. Benchmarks shown are the range across package sizes of a representative product for each form and strength — other manufacturers' products may differ.

Warfarin brand names

Warfarin is sold under 2 brand names in the FDA directory — Coumadin, Jantoven. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.

Coumadin Jantoven

Who makes Warfarin: manufacturers and labelers

18 companies list Warfarin products with the FDA. By number of product records, the largest are Remedyrepack Inc., Aphena Pharma Solutions - Tennessee, LLC, Golden State Medical Supply, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.

Remedyrepack Inc. 24 Aphena Pharma Solutions - Tennessee, LLC 15 Golden State Medical Supply, Inc. 15 A-S Medication Solutions 14 Bryant Ranch Prepack 14 Amneal Pharmaceuticals LLC 9 Exelan Pharmaceuticals Inc. 9 Sun Pharmaceutical Industries, Inc. 9 Teva Pharmaceuticals USA, Inc. 9 Upsher-Smith Laboratories, LLC 9 Coupler LLC 6 American Health Packaging 3 Cardinal Health 107, LLC 3 Northwind Health Company, LLC 3 Proficient Rx LP 3 Direct Rx 2 PD-Rx Pharmaceuticals, Inc. 1 Preferred Pharmaceuticals Inc. 1

Warfarin drug class (RxNorm)

Warfarin belongs to the Vitamin K Antagonist class.

Pharmacologic class Vitamin K Antagonist
Drug family (ATC) Vitamin K antagonists
How it works Vitamin K Inhibitors

Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.

Sources for this Warfarin page

Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.

📄
FDA-filed drug labels (SPL) Uses, dosing, warnings & side effects from SPL records retrieved through openFDA; the linked representative set can be verified on DailyMed. ✓ Linked label effective May 29, 2026
🏭
Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Warfarin.
📈
Real-world reportsThe FDA Adverse Event Reporting System (FAERS), served through openFDA.
🚨
Recalls & shortagesopenFDA drug-enforcement reports and the FDA drug-shortage database.
🧾 Clinical label set — FDA-filed SPL labels retained for Warfarin after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
82
Finished products in the current FDA directory
149
Companies listing them (makers, repackagers, distributors)
18
FDA labeler codes behind them ⓘ
21
Linked representative label ⓘ
Amneal Pharmaceuticals LLC
Linked label effective
May 29, 2026
Composite sections available
25
Linked SPL Set ID
558b7a0d-5490-4c1b-802e-3ab3f1efe760
Linked SPL Document ID
caa13d7d-5a78-412c-8e5e-e03a51164e96
Open the linked representative label on DailyMed ↗

How this page is built

HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Amneal Pharmaceuticals LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →