Which laboratory test is essential for monitoring warfarin therapy?

Monitoring warfarin therapy is essential for ensuring its efficacy and safety, as warfarin is a widely used anticoagulant that can significantly increase the risk of bleeding if not properly managed. The International Normalized Ratio (INR) is the key laboratory test used to evaluate the anticoagulation effect of warfarin.

The INR is a standardized measure of blood coagulation that helps determine how long it takes for blood to clot. For patients on warfarin, the INR must be regularly monitored to maintain it within a specific therapeutic range, typically between 2.0 and 3.0 for many conditions, although this can vary based on individual patient needs. High INR values indicate a higher risk of bleeding, while low values suggest that the warfarin dose may be inadequate, posing a risk for thrombosis.

In contrast, the other tests mentioned serve different purposes. A complete blood count (CBC) is useful for evaluating overall health and identifying conditions like anemia or infection, but it does not provide specific information about anticoagulation status. A lipid profile is used to assess cardiovascular risk by measuring different types of cholesterol and triglycerides, which is not relevant to monitoring warfarin therapy. An electrolyte panel assesses the levels of vital minerals in