What is the standard immediate reversal for warfarin in a patient requiring urgent surgery?

• A. Plasma derived factor concentrates.
• B. Prothrombin complex concentrate (PCC).
• C. Vitamin K.
• D. Fresh frozen plasma.

Answer: (C)

Warfarin blocks the liver’s production of vitamin K–dependent clotting factors II, VII, IX, and X. To reverse warfarin, you need to restore the body's ability to make those factors. Giving vitamin K provides the necessary cofactor so the liver can resume making the clotting proteins, reestablishing the coagulation cascade. This is the standard immediate reversal because it directly counters the drug’s mechanism and starts the restoration of normal coagulation. In truly urgent situations, clinicians may also use factor concentrates (such as PCC) or FFP to achieve faster, more immediate correction, but initiating vitamin K is the essential first step for reversal.