Final answer:
Patients starting warfarin should be instructed to avoid Aspirin (option A) and NSAIDs like ibuprofen due to the increased risk of bleeding. Acetaminophen should be used with caution. Antacids generally do not interact with warfarin, but patients should follow healthcare provider advice regarding their use.
Step-by-step explanation:
When a patient is starting a new prescription for warfarin, a nurse should instruct the patient to avoid certain over-the-counter (OTC) medications that may interact with warfarin and increase the risk of bleeding. Specifically, Aspirin and other NSAIDs (Nonsteroidal Anti-Inflammatory Drugs), such as ibuprofen and naproxen, should be avoided. Aspirin and NSAIDs can cause an increased risk of gastrointestinal ulcers and bleeding. Both aspirin and ibuprofen can interfere with platelet function and increase bleeding risk, which is particularly concerning for patients taking warfarin, a medication that also affects blood clotting.
Acetaminophen (paracetamol), while generally considered to have fewer interactions with warfarin, should still be used with caution and in limited amounts as it can alter warfarin levels with chronic use. Antacids generally do not have a direct interaction with warfarin, but they can affect the absorption of other medications and should be used as directed by a healthcare provider.
In summary, the nurse should advise the patient to avoid Aspirin, ibuprofen, and other NSAIDs while taking warfarin due to the increased risk of bleeding. Acetaminophen should be used carefully, and consultation with a healthcare provider is recommended before the use of any OTC medications.