A nurse is caring for a client who has deep vein thrombosis and has been on heparin continuous infusion for 5 days. The provider prescribes warfarin PO without discontinuing the heparin. The client asks the nurse why both anticoagulants are necessary. Which of the following statements should the nurse make?

Choice A rationale This statement is incorrect because warfarin requires several days to become therapeutic, so discontinuing the heparin immediately would leave the client unprotected against new clot formation. The nurse should not unilaterally discontinue a prescribed medication without a specific provider order, and doing so would be a deviation from the standard bridging protocol for transitioning from heparin to warfarin. Choice B rationale Warfarin is an oral anticoagulant that works by inhibiting vitamin K-dependent clotting factors, a process that takes 5 to 7 days to fully deplete existing factors and reach a therapeutic international normalized ratio (INR) of 2.0 to 3.0. Heparin, which works instantly via antithrombin activation, is therefore maintained simultaneously until the INR confirms warfarin has reached a stable protective level. Choice C rationale This statement is inaccurate because neither heparin nor warfarin actively dissolve existing clots; rather, they prevent the extension of existing clots and the formation of new clots. Clot dissolution is managed by the body's natural fibrinolytic system or by thrombolytic (clot-busting) medications such as alteplase, which are different drug classes entirely. Choice D rationale Heparin does not increase the effects of warfarin; they work through entirely different mechanisms in the coagulation cascade. While the combined use allows for an overlap and is necessary for safety, it does not chemically enhance warfarin's function. The length of hospital stay is determined by clinical stability, not by this specific drug interaction. —.