A client who had a pulmonary embolism is receiving IV heparin and has just begun taking his first dose of warfarin (Coumadin). The client asks the nurse, "How long will this pill take in order to prevent me from developing more clots

Question

I would like to go home soon." The nurse responds:
A) "It usually takes 2 to 3 days for warfarin to become therapeutic, meaning your blood will be thin enough to prevent further clot formation."
B) "I don't really know. Right now you are on two blood thinners, so we won't be able to tell if it's working until the doctor discontinues your heparin drip."
C) "That's a good question. If warfarin has a long half-life, it could take many days. I will have to ask the pharmacist this question."
D) "First, we have to have your health care provider switch you from IV heparin to a low molecular weight heparin, which you need to inject in your belly."

Answer 1

Ans: A
Feedback:
The anticoagulant drugs warfarin and heparin are used to prevent thromboembolic disorders, such as deep vein thrombosis and pulmonary embolism. Warfarin acts by decreasing prothrombin. It alters vitamin K in a manner that reduces its ability to participate in the synthesis of the vitamin K–dependent coagulation factors in the liver. Warfarin's maximum effect takes 36 to 72 hours because of the varying half-lives of different clotting factors that remain in the circulation. Heparin ultimately suppresses the formation of fibrin and therefore inhibits coagulation. The low molecular weight heparins are given by subcutaneous injection and require less frequent administration and monitoring compared with the standard (unfractionated) heparin. Clients usually are not sent home with an IV medication. Once warfarin is in therapeutic range, heparin or low molecular weight heparins are no longer required.