In anticoagulation management, which statement is accurate?

• A. DOACs require constant INR monitoring.
• B. Warfarin has fewer dietary restrictions than DOACs.
• C. Warfarin requires regular INR monitoring and consistency of vitamin K intake.
• D. All anticoagulants require the same monitoring.

Answer: (C)

Understanding how different anticoagulants are monitored helps explain why this statement is correct. Warfarin works by inhibiting vitamin K–dependent clotting factors, but its effect is highly variable from person to person and is influenced by dietary vitamin K intake. Because of this narrow therapeutic window, patients on warfarin require regular INR (international normalized ratio) monitoring to keep their anticoagulation within the target range and to adjust the dose as needed. Consistency in vitamin K intake matters because sudden increases or decreases in vitamin K can push the INR toward under- or over-anticoagulation, increasing the risk of thrombosis or bleeding.

Direct oral anticoagulants (DOACs) have more predictable effects and are given in fixed doses, so routine INR monitoring isn’t needed. They don’t depend on vitamin K in the same way, though they do require other considerations like renal function for dosing. While some monitoring may be done for safety in special populations, the standard practice does not involve regular INR checks or dietary vitamin K adjustments for DOACs.

So the accurate statement reflects that warfarin requires regular INR monitoring and consistent vitamin K intake.