Which statement reverses the anticoagulant effect of warfarin?

Which statement reverses the anticoagulant effect of warfarin?

• A. Protamine sulfate
• B. Vitamin K
• C. Desmopressin
• D. Platelets

Answer: (B)

Warfarin works by blocking the enzyme that regenerates active vitamin K, which lowers the production of vitamin K–dependent clotting factors II, VII, IX, and X. Reversing its effect means restoring that vitamin K–dependent factor production. Giving vitamin K supplies the needed cofactor to regenerate active vitamin K, allowing the liver to synthesize those clotting factors again and reestablish coagulation. The faster you need reversal, the higher the urgency for vitamin K, sometimes with additional products like plasma or concentrates to supply clotting factors right away. Other options don’t counteract warfarin’s mechanism: protamine sulfate reverses heparin anticoagulation, desmopressin can boost certain clotting factors in specific bleeding disorders but doesn’t reverse warfarin, and platelets help with platelet-related bleeding but don’t reverse the anticoagulant effect of warfarin.

Warfarin works by blocking the enzyme that regenerates active vitamin K, which lowers the production of vitamin K–dependent clotting factors II, VII, IX, and X. Reversing its effect means restoring that vitamin K–dependent factor production. Giving vitamin K supplies the needed cofactor to regenerate active vitamin K, allowing the liver to synthesize those clotting factors again and reestablish coagulation. The faster you need reversal, the higher the urgency for vitamin K, sometimes with additional products like plasma or concentrates to supply clotting factors right away. Other options don’t counteract warfarin’s mechanism: protamine sulfate reverses heparin anticoagulation, desmopressin can boost certain clotting factors in specific bleeding disorders but doesn’t reverse warfarin, and platelets help with platelet-related bleeding but don’t reverse the anticoagulant effect of warfarin.