Which lab value is essential to monitor after initiating Coumadin therapy?

Monitoring the INR (International Normalized Ratio) is critical after starting Coumadin (warfarin) therapy because this anticoagulant alters the clotting cascade by inhibiting vitamin K-dependent clotting factors. The INR provides a standardized measure of how well and how quickly blood coagulates.

Establishing an appropriate therapeutic range for INR is essential to ensure effective anticoagulation while minimizing the risk of bleeding complications. Typically, for most indications, the therapeutic INR range is between 2.0 and 3.0, although it can vary depending on the specific condition being treated.

Maintaining the INR within this range is crucial for patient safety, making its monitoring the key lab value after initiating Coumadin therapy. If the INR is too low, the patient may be at risk for thrombosis, while a high INR indicates an increased risk of bleeding. Thus, regular monitoring of INR helps to adjust the warfarin dosage effectively to achieve and maintain therapeutic levels.