Question 50

Aspirin (Bayer) has a high risk of causing a serious drug-to-drug interaction with warfarin (Coumadin).

Aspirin (Bayer) is known to significantly increase the risk of bleeding when taken in conjunction with warfarin due to its antiplatelet effects, making it the medication among the choices that poses the highest risk of a serious interaction.

A) Diphenhydramine (Benadryl)

Diphenhydramine does not have a significant interaction with warfarin. While it can cause drowsiness and other side effects, it is not known to enhance the anticoagulant effects of warfarin or increase bleeding risk, making it a safer choice in this context.

B) Aspirin (Bayer)

Aspirin is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits platelet aggregation, which can lead to an increased risk of bleeding when used with warfarin. This interaction can be serious and requires careful management, making it the correct answer for this question.

C) Famotidine (Pepcid)

Famotidine is an H2 antagonist primarily used to treat gastric conditions. It is not known to interact significantly with warfarin, thus posing minimal risk for serious drug-to-drug interactions in patients taking warfarin.

D) Acetaminophen (Tylenol)

While generally considered safer than NSAIDs, acetaminophen can still pose some risk when taken with warfarin. However, it does not significantly enhance the anticoagulant effect compared to aspirin, which makes it a less critical concern in terms of drug interactions.

Conclusion

Aspirin (Bayer) is the only medication listed that poses a serious risk of interaction with warfarin due to its anticoagulant properties, which can lead to increased bleeding. Other options, such as diphenhydramine, famotidine, and acetaminophen, do not share this high level of interaction risk, and thus, they are safer alternatives when managing patients on warfarin therapy.