Warfarin (Coumadin)

Management of thromboembolic disorders: For prophylaxis, Rx, and prevention of recurrence of thromboembolic events including DVT, pulm embolism, thrombosis of grafts. Prevention of arterial emboli associated with prosthetic heart valves, nonvalvular AFib, acute MI. Prevention of MI, stroke, and recurrent MI. Rx for deficiency of antithrombin III, protein C, protein S.

Unknown number of individuals receiving the drug.

Hemorrhage (minor to major life risk)

Purple-toe syndrome or warfarin necrosis

Teratogenicity in pregnancy (decreases synthesis of vitamin K-dependent clotting factors by fetus)

Risk of thrombosis/bleeding if discontinued periop

Major drug interactions

Many drugs affect action of warfarin. List is extensive and continually expanding. Be concerned about other drugs that potentiate bleeding (e.g., antiplatelet agents, ASA, NSAIDs); and drugs that displace warfarin from protein-binding sites or that increase or decrease vitamin K levels.