A client taking warfarin (Coumadin) requests an aspirin for headache relief. What is the nurse's best response?

• A. Administer 650 mg of acetylsalicylic acid (ASA) and reassess pain in 30 minutes.
• B. Teach the client of potential drug interactions with anticoagulants.
• C. Explain to the client that ASA is contraindicated and administer ibuprofen as ordered.
• D. Explain that the headache is an expected side effect and will subside shortly.

Answer: (B)

The main concept tested is safety around anticoagulant-NSAID interactions. Warfarin and aspirin both affect clotting—warfarin by reducing vitamin K–dependent clotting factors, and aspirin by inhibiting platelet function. Using them together markedly increases the risk of serious bleeding, including GI bleeding and intracranial hemorrhage. The nurse’s best response is to educate the client about these potential interactions and the need to avoid taking aspirin or other NSAIDs without consulting the provider. This keeps the patient safe and opens the door to safer options, such as acetaminophen for headache relief or discussing alternatives with the clinician, who may adjust therapy or monitor INR if an NSAID is truly needed.

Administering aspirin would expose the patient to that bleeding risk immediately. Replacing with ibuprofen still carries bleeding and interaction risks and isn’t a blanket safe substitute. Claiming that headache is a expected side effect of warfarin is inaccurate, and it doesn’t address the safety concern or the need for medical guidance.