Progressive Care Nursing Certification (PCCN) Practice Exam

What medication is used as an antidote for warfarin overdose?

1. Vitamin A

2. Vitamin B12

3. Vitamin C

4. Vitamin K

The correct answer is: Vitamin K

Warfarin is an anticoagulant that works by inhibiting the vitamin K-dependent synthesis of clotting factors in the liver. In cases of warfarin overdose, the primary concern is reversing the anticoagulant effects to prevent significant bleeding. Vitamin K is crucial because it is the antidote that helps to restore the levels of clotting factors that have been diminished by warfarin. When vitamin K is administered, it aids in the synthesis of clotting factors II (prothrombin), VII, IX, and X, which is essential for normal blood coagulation. This can be given orally in mild cases or intravenously when rapid reversal is needed. Other options, such as vitamin A, vitamin B12, and vitamin C, do not have a role in reversing the anticoagulation effects of warfarin. They do not influence the synthesis of the vitamin K-dependent clotting factors, and therefore are not effective antidotes in this context.