Warfarin: study card

Generic name

Warfarin

Class

Vitamin K antagonist anticoagulant

Mechanism

Inhibits synthesis of vitamin K-dependent clotting factors II, VII, IX and X and anticoagulant proteins C and S.

Used for

Venous thrombosis and PE (prevent / treat); Thromboembolism with AF or valve replacement; Reduce death, reinfarction and stroke after MI

Common side effects

Hemorrhage; Hypersensitivity reactions; Elevated liver enzymes; Vasculitis

Boxed warning

Can cause major or fatal bleeding; monitor INR regularly; drugs and diet affect INR.

Warnings

Tissue necrosis; Calciphylaxis; Pregnancy is contraindicated except in pregnant women with mechanical heart valves at high risk of thromboembolism

Interactions

Drugs that increase bleeding risk; Antibiotics and antifungals; CYP2C9, 1A2 or 3A4 inhibitors / inducers

Brand questions use only name pairings verified against the linked product source. Unverified pairings are withheld from these questions; the other study content remains available.

Label date: 20260825 · For learning, not clinical decisions. US label and brand information; always consult the current source.

Source snapshot checked: 2026-10-21. The source document and selected fields were compared. The complete card has not had an independent clinical review.