A nurse is caring for a patient who is taking warfarin (Coumadin). Which of the following laboratory values should the nurse monitor regularly?

Warfarin (Coumadin) is an anticoagulant medication that prevents blood clots from forming or growing larger. It works by inhibiting the synthesis of vitamin K-dependent clotting factors in the liver. Warfarin can increase the risk of bleeding, so patients should monitor for signs of bleeding and report them to their healthcare provider.Some signs of bleeding are bruising, nosebleeds, gum bleeding, blood in urine or stool, and heavy menstrual bleeding.

Choice A is wrong because patients taking warfarin should not avoid foods that are high in vitamin K, but rather maintain a consistent intake of vitamin K.

Vitamin K is found in green leafy vegetables, such as spinach, kale, broccoli, and cabbage.Vitamin K can counteract the effects of warfarin and lower its effectiveness, so sudden changes in vitamin K intake can alter the patient’s response to warfarin.

Choice B is wrong because patients taking warfarin should not take aspirin for pain relief.

Aspirin is a nonsteroidal anti-inflammatory drug (NSAID) that can also inhibit platelet aggregation and increase the risk of bleeding.

Patients taking warfarin should avoid NSAIDs and other medications that can interact with warfarin, such as antibiotics, antifungals, anticonvulsants, and herbal supplements.Patients should consult their healthcare provider before taking any new medications or supplements.

Choice D is wrong because patients taking warfarin should not use a hard-bristled toothbrush.

A hard-bristled toothbrush can cause gum bleeding and increase the risk of oral infection.

Patients taking warfarin should use a soft-bristled toothbrush and floss gently to prevent gum bleeding.They should also avoid dental procedures that can cause bleeding, such as extractions, implants, or scaling.

This statement indicates a need for further teaching because aspirin is an antiplatelet drug that can increase the risk of bleeding when taken with warfarin (Coumadin), an anticoagulant.The patient should avoid aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) and use acetaminophen (Tylenol) or other pain relievers that do not affect blood clotting.

Choice A is wrong because it is a correct statement.The patient should avoid activities that could cause injury, such as contact sports, shaving with a razor, or using sharp objects, because they could lead to bleeding complications while on warfarin (Coumadin).

Choice C is wrong because it is a correct statement.The patient should report any unusual bleeding to their healthcare provider, such as nosebleeds, easy bruising, blood in urine or stool, heavy menstrual bleeding, or bleeding gums.

These could be signs of excessive anticoagulation or adverse effects of warfarin (Coumadin).

Choice D is wrong because it is a correct statement.The patient should use a soft-bristled toothbrush and floss gently to prevent gum bleeding while on warfarin (Coumadin).The patient should also avoid dental procedures without consulting their healthcare provider first.

The normal range for INR (international normalized ratio), a test that measures how long it takes blood to clot, is 0.75-1.25 for people who are not taking warfarin (Coumadin).For people who are taking warfarin (Coumadin), the therapeutic range is usually 2-3, depending on the condition being treated.The patient’s INR level should be monitored regularly to adjust the dose of warfarin (Coumadin) and prevent bleeding or clotting complications.