Last reviewed 2026-04-22 · How we verify

Warfarin duration

Warfarin inhibits vitamin K-dependent clotting factors to reduce blood clot formation.

Warfarin inhibits vitamin K-dependent clotting factors to reduce blood clot formation. Used for Atrial fibrillation for stroke prevention, Venous thromboembolism (DVT/PE) treatment and prevention, Mechanical heart valve thromboprophylaxis.

At a glance

Mechanism of action

Warfarin is a vitamin K antagonist that blocks the synthesis of vitamin K-dependent coagulation factors (II, VII, IX, and X) in the liver. By depleting these essential clotting factors, warfarin decreases the ability of blood to form clots, thereby preventing thromboembolism. The duration of warfarin therapy varies by indication and is typically managed through INR (International Normalized Ratio) monitoring.

Approved indications

• Atrial fibrillation for stroke prevention
• Venous thromboembolism (DVT/PE) treatment and prevention
• Mechanical heart valve thromboprophylaxis
• Acute myocardial infarction with high thromboembolic risk

Common side effects

• Bleeding (major)
• Bleeding (minor)
• Warfarin-induced skin necrosis
• Alopecia
• Nausea

Key clinical trials

• LVT DURATION: Pilot Study of Anticoagulation Duration for Left Ventricular Thrombus (PHASE2)
• International Care Bundle Evaluation in Cerebral Hemorrhage Research (PHASE4)
• Sunitinib or Cediranib for Alveolar Soft Part Sarcoma (PHASE2)
• Assessing the Neurological Outcomes After Atrial Fibrillation Ablation for Rhythm Control
• DOAC Versus VKA in Patients With Non-high-risk APS : Prospective Cohort Study
• Efficacy and Safety of Endovascular Recanalization for Acute Basilar Artery Occlusion With Extended Time Window (ANGEL-BAO) (NA)
• Anticoagulation in Post MI LV Thrombus Trial in Nepal (PHASE4)
• The Nordic Aortic Valve Intervention Trial 4 (NOTION-4) (NA)

Primary sources

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