Why is it important to monitor INR levels in patients on warfarin?

Monitoring INR levels in patients on warfarin is crucial primarily to prevent overdosing and the associated risk of bleeding. Warfarin is an anticoagulant that works by inhibiting vitamin K-dependent clotting factors in the liver, which are essential for normal blood coagulation. The International Normalized Ratio (INR) is a standardized measure used to assess the anticoagulation effect of warfarin, ensuring that the patient remains within a therapeutic range that balances the prevention of clot formation and the risk of excessive bleeding.

If the INR is too low, the patient may not receive adequate anticoagulation, increasing the risk of thrombosis. Conversely, if the INR is too high, the risk of bleeding complications rises significantly. Regular monitoring helps clinicians adjust the warfarin dosage accurately to maintain the INR within the target range, providing effective management of conditions like atrial fibrillation or venous thromboembolism while minimizing potentially severe side effects.

The other options, while related to general health monitoring, do not directly pertain to the primary reason for INR monitoring in patients taking warfarin. For instance, liver and kidney functions are important for overall patient health, but they are not the direct focus of INR management, which is specifically concerned with