In a patient taking warfarin with an INR of 4, which medication should be administered?

In the scenario of a patient taking warfarin with an INR of 4, the appropriate medication to administer is Vitamin K. Warfarin is an anticoagulant that works by inhibiting the synthesis of vitamin K-dependent coagulation factors. An elevated INR indicates that the patient is at increased risk for bleeding due to the anticoagulant effect of warfarin.

Vitamin K acts as an antidote to warfarin by promoting the synthesis of clotting factors that are inhibited by warfarin, specifically factors II, VII, IX, and X. Administering Vitamin K helps to restore the normal levels of these factors in the bloodstream, thus reducing the INR and mitigating the risk of bleeding complications.

In contrast, while other options might be considered in certain situations, they are not the first-line treatment for an elevated INR related to warfarin. For instance, protamine sulfate specifically reverses the effects of heparin, not warfarin. Factor VIIa is usually reserved for severe bleeding situations or specific conditions, and fresh frozen plasma may be used in more acute scenarios requiring immediate reversal of anticoagulation or when rapid volume resuscitation is also needed, but it is less targeted than Vitamin K for reversing warfarin’s