National Physical Therapy Examination (NPTE) Practice Exam

Which over-the-counter medication should be of GREATEST concern to a physical therapist for a patient prescribed warfarin?

1. Diphenhydramine (Benadryl)

2. Cetirizine (Zyrtec)

3. Omeprazole (Prilosec)

4. Acetylsalicylic acid (Aspirin)

The correct answer is: Acetylsalicylic acid (Aspirin)

The greatest concern for a physical therapist regarding a patient prescribed warfarin relates to the potential for increased bleeding risk associated with acetylsalicylic acid, commonly known as aspirin. Warfarin is an anticoagulant that works by inhibiting the synthesis of vitamin K-dependent clotting factors, thereby prolonging the time it takes for the blood to clot. When aspirin is taken concurrently with warfarin, it can potentiate the anticoagulant effects of warfarin due to its own antiplatelet properties. This combination can lead to a significantly heightened risk of bleeding complications, which is a critical concern for healthcare providers. The other medications listed do not pose the same level of risk. Diphenhydramine and cetirizine are antihistamines that generally do not interact with warfarin in a way that significantly affects clotting or increases bleeding risk. Omeprazole is a proton pump inhibitor that may have some minor interactions with warfarin, but these are typically less concerning compared to the effects of aspirin. Therefore, the use of aspirin alongside warfarin requires careful monitoring and often avoidance, which highlights the concern for physical therapists managing patients on anticoagulant therapy.