A patient on warfarin has an INR of 3.2. What does this reflect?

A patient on warfarin has an INR of 3.2. What does this reflect?

• A. Therapeutic anticoagulation
• B. Subtherapeutic anticoagulation
• C. Supratherapeutic anticoagulation; bleeding risk; may require dose adjustment
• D. No effect on bleeding risk

Answer: (C)

INR is used to gauge how warfarin is affecting blood clotting and to keep anticoagulation within a safe, targeted range. For most patients, the therapeutic INR range is about 2.0 to 3.0. An INR of 3.2 is above that typical target, which means supratherapeutic anticoagulation. This reflects an increased risk of bleeding, so the usual response is to reassess and likely reduce or hold the warfarin dose and recheck the INR promptly. Consider potential factors that can raise INR, such as drug interactions, changes in diet (vitamin K intake), liver function, or acute illness, and monitor for any signs of bleeding. In some scenarios, like certain mechanical valves, the target range may be higher, but 3.2 generally indicates the anticoagulation effect is stronger than desired and may need dose adjustment.

INR is used to gauge how warfarin is affecting blood clotting and to keep anticoagulation within a safe, targeted range. For most patients, the therapeutic INR range is about 2.0 to 3.0. An INR of 3.2 is above that typical target, which means supratherapeutic anticoagulation. This reflects an increased risk of bleeding, so the usual response is to reassess and likely reduce or hold the warfarin dose and recheck the INR promptly. Consider potential factors that can raise INR, such as drug interactions, changes in diet (vitamin K intake), liver function, or acute illness, and monitor for any signs of bleeding. In some scenarios, like certain mechanical valves, the target range may be higher, but 3.2 generally indicates the anticoagulation effect is stronger than desired and may need dose adjustment.