A client has been diagnosed with atrial fibrillation. The physician prescribed warfarin (Coumadin) to be taken on a daily basis. The nurse instructs the client to avoid using which of the following...

A client has been diagnosed with atrial fibrillation. The physician prescribed warfarin (Coumadin) to be taken on a daily basis. The nurse instructs the client to avoid using which of the following over-the-counter medications while taking warfarin?

1. Aspirin.

2. Diphenhydramine (Benadryl).

3. Digoxin (Lanoxin).

4. Pseudoephedrine (Sudafed).