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This page presents data from the FDA Adverse Event Reporting System (FAERS) and the FDA-approved drug label. A report submitted to FAERS does not prove a drug caused the reported event. Always consult a healthcare provider about medications.

Warfarin Sodium (warfarin)

Last updated: June 5, 2026

Warfarin Sodium is the brand name for warfarin. According to the FDA-approved label, Warfarin sodium tablets are indicated for: Prophylaxis and treatment of venous thrombosis and its extension, pulmonary embolism (PE). Prophylaxis and treatment of thromboembolic complications associated with atrial fibrillation (AF) and/or cardiac valve replacement. FAERS contains 125,605 submissions naming this drug from 1999 through 2026; the top three reactions cited are international normalised ratio increased, dyspnoea, and drug interaction.

Most-Reported Reactions

Counts of the reactions most often cited in FAERS submissions that named Warfarin Sodium. Inclusion here does not establish causation - submitters describe what was observed, not what was confirmed. One submission can list several reactions, so the totals exceed the report count.

INTERNATIONAL NORMALISED RATIO INCREASED 10,312 DYSPNOEA 8,450 DRUG INTERACTION 6,331 FATIGUE 6,188 NAUSEA 5,947 DIARRHOEA 5,940 DIZZINESS 5,192 DRUG INEFFECTIVE 5,153 FALL 4,834 DEATH 4,742 HEADACHE 4,684 ASTHENIA 4,386 PNEUMONIA 4,121 HAEMORRHAGE 4,056 ANAEMIA 3,954

Submissions Per Quarter

Quarterly count of FAERS submissions that named Warfarin Sodium. Ups and downs on this chart can track prescribing volume, news cycles, or shifts in how reports get filed, rather than the drug becoming safer or more dangerous.

1999 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026

From the FDA-Approved Label

Excerpts from the official FDA-approved prescribing information for Warfarin Sodium. This is the authoritative source on indications, warnings, and known adverse reactions.

Indications

1 INDICATIONS AND USAGE Warfarin sodium tablets are indicated for: Prophylaxis and treatment of venous thrombosis and its extension, pulmonary embolism (PE). Prophylaxis and treatment of thromboembolic complications associated with atrial fibrillation (AF) and/or cardiac valve replacement. Reduction in the risk of death, recurrent myocardial infarction (MI), and thromboembolic events such as stroke or systemic embolization after myocardial infarction. Limitations of Use Warfarin sodium tablets have no direct effect on an established thrombus, nor does it reverse ischemic tissue damage. Once a thrombus has occurred, however, the goals of anticoagulant treatment are to prevent further extension of the formed clot and to prevent secondary thromboembolic complications that may result in serious and possibly fatal sequelae. Warfarin sodium tablets are a vitamin K antagonist indicated for: Prophylaxis and treatment of venous thrombosis and its extension, pulmonary embolism ( 1 ) Prophylaxis and treatment of thromboembolic complications associated with atrial fibrillation and/or cardiac valve replacement ( 1 ) Reduction in the risk of death, recurrent myocardial infarction, and thromboemb...

Adverse Reactions (from label)

6 ADVERSE REACTIONS The following serious adverse reactions to warfarin sodium are discussed in greater detail in other sections of the labeling: Hemorrhage [see Boxed Warning, Warnings and Precautions (5.1), and Overdosage ( 10 )] Tissue Necrosis [see Warnings and Precautions ( 5.2 )] Calciphylaxis [see Warnings and Precautions ( 5.3 )] Acute Kidney Injury [see Warnings and Precautions ( 5.4 )] Systemic Atheroemboli and Cholesterol Microemboli [see Warnings and Precautions ( 5.5 )] Limb Ischemia, Necrosis, and Gangrene in Patients with HIT and HITTS [see Warnings and Precautions ( 5.6 )] Other Clinical Settings with Increased Risks [see Warnings and Precautions ( 5.8 )] Other adverse reactions to warfarin sodium include: Immune system disorders: hypersensitivity/allergic reactions (including urticaria and anaphylactic reactions) Vascular disorders: vasculitis Hepatobiliary disorders: hepatitis, elevated liver enzymes. Cholestatic hepatitis has been associated with concomitant administration of warfarin sodium and ticlopidine. Gastrointestinal disorders: nausea, vomiting, diarrhea, taste perversion, abdominal pain, flatulence, bloating Skin disorders: rash, dermatitis (including bu...

FDA label effective date: 2025-06-17

Disclaimer

AdverseEvent.ai is not affiliated with the FDA. Adverse-event counts come from the FDA Adverse Event Reporting System (FAERS). Drug labels come from the FDA drug label dataset. A report submitted to FAERS does not prove a drug caused the reported event — always consult a healthcare provider about medications. This site is for informational purposes only and is not medical advice.