It is important for the nurse to assess for the use of complementary and alternative medicine (CAM) because:

A. Easy bruising indicates the medication is effective: While some bruising is possible, excessive bruising doesn't necessarily mean the medication is working effectively. It could indicate excessive anticoagulation, requiring dose adjustments.

B. Inject the medication deep into the thigh muscle: Heparin is injected subcutaneously, targeting the fatty tissue layer just beneath the skin. Injecting into the muscle can be painful and decrease absorption.

C. Expect stools to become black and tarry: Black stools can be a sign of upper gastrointestinal bleeding, a potential but uncommon side effect. The nurse should instruct the client to report any black stools but not expect them as a normal occurrence.

D. Use a soft bristle toothbrush: This is important because heparin increases bleeding risk, and a soft-bristled toothbrush minimizes gum irritation and potential bleeding.

A. Ferrous sulfate: This is an iron supplement and wouldn't be used to reverse warfarin's anticoagulant effect.

B. Prednisone: This is a steroid medication used for various inflammatory conditions and wouldn't be used to address excessive blood thinning.

C. Vitamin K: Vitamin K is the antidote for warfarin poisoning or excessive anticoagulation. By providing vitamin K, the body can resume producing clotting factors, counteracting warfarin's effect.

D. Heparin: This is another blood thinner medication. While it can be used in specific situations, it wouldn't be the first choice to reverse warfarin's effect because it adds another layer of anticoagulation, which could be risky.