A patient on warfarin has an increased INR. Which vitamin reverses warfarin anticoagulation?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $25.99Unlock all

Study for the NBME Form 13 Test with our comprehensive quiz collection, featuring flashcards and multiple-choice questions to ensure your readiness. Enhance your knowledge with detailed explanations for each question.

Multiple Choice

A patient on warfarin has an increased INR. Which vitamin reverses warfarin anticoagulation?

Explanation:
Warfarin blocks the enzyme that recycles vitamin K, so the liver can’t activate the vitamin K–dependent clotting factors II, VII, IX, and X. Replacing vitamin K allows those factors to be produced again, reducing the elevated INR and restoring clotting function. Therefore, vitamin K (phytomenadione) reverses warfarin anticoagulation. The other vitamins listed don’t influence the coagulation cascade or reverse warfarin’s effect, so they won’t normalize the INR. In urgent reversal, vitamin K can be given intravenously (often with other products like FFP or PCC for rapid effect); for less urgent cases, oral vitamin K is used.

Warfarin blocks the enzyme that recycles vitamin K, so the liver can’t activate the vitamin K–dependent clotting factors II, VII, IX, and X. Replacing vitamin K allows those factors to be produced again, reducing the elevated INR and restoring clotting function. Therefore, vitamin K (phytomenadione) reverses warfarin anticoagulation.

The other vitamins listed don’t influence the coagulation cascade or reverse warfarin’s effect, so they won’t normalize the INR. In urgent reversal, vitamin K can be given intravenously (often with other products like FFP or PCC for rapid effect); for less urgent cases, oral vitamin K is used.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy