Which of the following is a commonly used anticoagulant medication?

Warfarin is a commonly used anticoagulant medication primarily used to prevent blood clots in patients at risk for thromboembolic events, such as those with atrial fibrillation, venous thromboembolism, or after certain surgical procedures. It works by inhibiting vitamin K epoxide reductase, an enzyme essential for the synthesis of several clotting factors in the liver, which decreases the blood's ability to clot.

In terms of its role in interventional radiology, controlling anticoagulation is essential for procedures to minimize the risk of bleeding while also preventing thrombosis during vascular interventions. Warfarin requires regular monitoring with INR (International Normalized Ratio) to ensure the therapeutic range is achieved, which is crucial for patient safety during interventions.

The other medications listed serve different purposes; for instance, aspirin is an antiplatelet agent, lisinopril is an ACE inhibitor used to manage hypertension and heart failure, and hydralazine is a vasodilator typically used for hypertension. These do not serve the same anticoagulation purpose as Warfarin.