A nurse is caring for a patient 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 reason: Heparin does not increase the effects of warfarin. Instead, it provides immediate anticoagulation while warfarin takes time to reach therapeutic levels. The statement is misleading and incorrect. Choice B reason: Discontinuing heparin prematurely can leave the patient inadequately anticoagulated, increasing the risk of clot propagation or embolism. The nurse should not suggest stopping heparin without understanding the pharmacodynamics of warfarin. Choice C reason: Warfarin requires several days to inhibit clotting factors II and X, which have long half-lives. Heparin provides immediate anticoagulation and is continued until the INR is therapeutic for at least 24–48 hours, ensuring continuous protection against thromboembolism. Choice D reason: Neither heparin nor warfarin dissolves clots. They prevent further clot formation and allow the body’s natural fibrinolytic processes to break down existing clots. The statement is inaccurate and reflects a misunderstanding of anticoagulant mechanisms.