What does the INR monitor in patients?

The International Normalized Ratio (INR) is a laboratory measurement used primarily to monitor the effectiveness and safety of anticoagulant therapy, particularly in patients taking warfarin. Warfarin is a medication that increases the time it takes for blood to clot; therefore, measuring the INR helps healthcare providers determine whether a patient's blood is adequately anticoagulated to reduce the risk of thromboembolic events, such as strokes or deep vein thrombosis, while minimizing the risk of excessive bleeding.

An appropriate INR range indicates that a patient is receiving the right dose of warfarin. If the INR is too low, the patient may be at risk of developing clots; if it is too high, there’s an increased risk of bleeding complications. The INR is calculated based on the prothrombin time (PT), which measures the time it takes for blood to clot, and is standardized to account for variations in testing methods across different laboratories.

This monitoring is crucial for patients on anticoagulants to ensure that the medication is effectively preventing clot formation while maintaining patient safety.