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Coumadin (warfarin)
Inhibits vitamin K epoxide reductase, blocking the synthesis of vitamin K-dependent clotting factors (II, VII, IX, X) to prevent thrombosis.
Warfarin (Coumadin) is the oldest oral anticoagulant still in widespread use, approved in 1954. Despite being largely replaced by DOACs for atrial fibrillation, it remains essential for mechanical heart valves. Available generically worldwide, it requires regular INR monitoring.
At a glance
| Generic name | warfarin |
|---|---|
| Also known as | Coumadin, Jantoven |
| Sponsor | Generic (originally Wisconsin Alumni Research Foundation) |
| Drug class | Vitamin K antagonist (anticoagulant) |
| Target | Vitamin K epoxide reductase complex subunit 1-like protein 1, Cytochrome P450 2C9, Proprotein convertase subtilisin/kexin type 7 |
| Modality | Small molecule |
| Therapeutic area | Cardiovascular |
| Phase | FDA-approved |
| First approval | 1954-01-01 (United States) |
Mechanism of action
Warfarin inhibits vitamin K epoxide reductase, preventing the recycling of vitamin K needed to carboxylate clotting factors II, VII, IX, and X. Originally developed as a rat poison, it has been used therapeutically since the 1950s. Despite the advent of DOACs, warfarin remains essential for mechanical heart valves and some conditions. It requires regular INR monitoring and has significant food and drug interactions.
Approved indications
- Cerebral embolism
- Deep Vein Thrombosis with Pulmonary Embolism
- Deep venous thrombosis
- Myocardial Reinfarction Prevention
- Prevention of Thromboembolism with Chronic Atrial Fibrillation
- Prevention of deep vein thrombosis
- Pulmonary Thromboembolism Prevention
- Pulmonary thromboembolism
- Thromboembolic disorder
- Thromboembolism due to Prosthetic Heart Valves
- Thrombosis
Boxed warnings
- WARNING: BLEEDING RISK Warfarin sodium can cause major or fatal bleeding [see Warnings and Precautions ( 5.1 )] . Perform regular monitoring of INR in all treated patients [see Dosage and Administration ( 2.1 )] . Drugs, dietary changes, and other factors affect INR levels achieved with warfarin sodium therapy [see Drug Interactions ( 7 )] . Instruct patients about prevention measures to minimize risk of bleeding and to report signs and symptoms of bleeding [see Patient Counseling Information ( 17 )] . WARNING: BLEEDING RISK See full prescribing information for complete boxed warning. Warfarin sodium can cause major or fatal bleeding. ( 5.1 ) Perform regular monitoring of INR in all treated patients. ( 2.1 ) Drugs, dietary changes, and other factors affect INR levels achieved with warfarin sodium therapy. ( 7 ) Instruct patients about prevention measures to minimize risk of bleeding and to report signs and symptoms of bleeding. ( 17 )
Common side effects
- Hemorrhage
- Nausea
- Vomiting
- Diarrhea
- Rash
- Abdominal pain
- Pruritus
- Dermatitis
- Taste perversion
- Flatulence
- Bloating
- Alopecia
Serious adverse events
- Tissue Necrosis
- Calciphylaxis
- Acute Kidney Injury
- Systemic Atheroemboli and Cholesterol Microemboli
- Limb Ischemia, Necrosis, and Gangrene
- Hepatitis
- Cholestatic hepatitis
- Vasculitis
- Anaphylactic reactions
- Tracheal or tracheobronchial calcification
Key clinical trials
- Clinical Outcome During Warfarin Anticoagulation Monitored With "Fiix-INR" Compared to Standard Monitoring With INR.A Prospective Randomized Double-blinded Trial. (Phase 2)
- Sirolimus Combined With Low-dose Warfarin for the Treatment of Refractory Classic Paroxysmal Nocturnal Hemoglobinuria ,a Prospective Study (Phase 4)
- Fresh Frozen Plasma Versus Four Factor Prothrombin Complex Concentrate for Reversal of Vitamin K Antagonists in Intracranial Hemorrhage (NA)
- A Phase I Open-label Study to Evaluate the Effect of Multiple Doses of MDV3100 (ASP9785) on the Pharmacokinetics of Substrates for CYP2C8, CYP2C9, CYP2C19, and CYP3A4 in Patients With Castration-resis (Phase 1)
- An Open-Label, Single Centre Study to Assess the Pharmacokinetics and Pharmacodynamics of Warfarin When Co-Administered With Fostamatinib in Healthy Subjects (Phase 1)
- Antiplatelet Therapy for Patients Undergoing Transcatheter Aortic Valve Implantation (Phase 4)
- Safety and Effectiveness of Early Aspirin Administration After Mitral Valve Repair: a Prospective, Non-inferiority, Randomized Controlled Clinical Trial Protocol (Phase 4)
- Efficacy and Safety of Short-term Postoperative Anticoagulant Therapy to Prevente Thrombosis in Arterovenous Fistula (NA)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| FDA label | Mechanism, indications, dosing, boxed warnings, drug interactions |
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Coumadin CI brief — competitive landscape report
- Coumadin updates RSS · CI watch RSS
- Generic (originally Wisconsin Alumni Research Foundation) portfolio CI