Which therapy is monitored using Prothrombin Time?

Prothrombin Time (PT) is a blood test that measures how long it takes for blood to clot. This test is especially important for monitoring patients who are on anticoagulant therapy. Warfarin, also known as Coumadin, is an oral anticoagulant that works by inhibiting vitamin K-dependent clotting factors, which directly affects the clotting pathway that PT assesses. By monitoring PT, clinicians can adjust the dosage of Warfarin to maintain the patient within a therapeutic range, minimizing the risk of thromboembolic events while avoiding excessive bleeding.

The other options listed—Heparin, Aspirin, and Clopidogrel—are monitored differently. Heparin is typically monitored using activated partial thromboplastin time (aPTT). Aspirin and Clopidogrel are platelet inhibitors and do not have specific lab tests like PT that are used for monitoring their effects. Thus, PT is primarily relevant in the context of Warfarin therapy.