Which blood test is primarily used to monitor patients on Coumadin?

The primary blood test used to monitor patients on Coumadin (warfarin) is the International Normalized Ratio (INR). This test specifically measures the time it takes for blood to clot and is adjusted to account for variations in different laboratories, which makes it a reliable tool for managing anticoagulation therapy.

When a patient is on Coumadin, their goal is to maintain the INR within a specific therapeutic range to minimize the risk of blood clots while preventing excessive bleeding. Monitoring the INR allows healthcare providers to adjust the dose of Coumadin based on the patient’s response, ensuring effective anticoagulation therapy.

While the Prothrombin Time (PT) is also relevant, it is the INR that is primarily used for standardizing PT results, making INR the critical measurement for ongoing management. Tests like A1C are unrelated to coagulation and specifically evaluate blood glucose levels over time, while PTT is used primarily to monitor heparin therapy.