A client is prescribed warfarin for the prevention of venous thromboembolism (VTE) following a right knee replacement. What should the nurse have available for a warfarin overdose?

A. Vitamin K: Vitamin K is the antidote for warfarin overdose. Warfarin inhibits vitamin K-dependent clotting factors, and administering vitamin K reverses this effect by promoting the synthesis of clotting factors to control bleeding. B. Magnesium sulfate: Magnesium sulfate is used to treat conditions such as torsades de pointes and eclampsia but has no role in reversing the anticoagulant effects of warfarin. It does not impact coagulation pathways or vitamin K levels. C. Flumazenil: Flumazenil is an antidote for benzodiazepine overdose. It acts by antagonizing the effects of drugs like diazepam and lorazepam but has no effect on warfarin or anticoagulation reversal. D. Protamine sulfate: Protamine sulfate is the antidote for heparin and low-molecular-weight heparin overdose, not warfarin. It neutralizes heparin's anticoagulant properties but does not interact with vitamin K or affect warfarin action.