For patients on warfarin therapy, which test is used for monitoring?

The test primarily used for monitoring patients on warfarin therapy is the INR, which stands for International Normalized Ratio. This test assesses the time it takes for blood to clot and helps ensure that patients are maintaining their blood coagulation within a safe range. Warfarin works by inhibiting coagulation factors in the liver, and since its effect can vary between individuals, regular monitoring is crucial.

The INR standardizes prothrombin time (PT) results to account for variations between different laboratories and testing methods. A typical therapeutic INR range for patients on warfarin often falls between 2.0 to 3.0, depending on the condition being treated. Monitoring the INR helps prevent both thromboembolic events and complications related to over-anticoagulation, such as bleeding.

Although PT can be used to calculate the INR, the INR itself is the preferred and standardized measure for monitoring warfarin therapy. PTT is more relevant for patients on heparin therapy, and a complete blood count (CBC) is not specific for monitoring anticoagulation levels.