What is the therapeutic INR range listed for Warfarin in the material?

• A. 1-2
• B. 2-3.5
• C. 3-4.5
• D. 0-1

Answer: (B)

Warfarin therapy aims for an INR that balances preventing clots with avoiding bleeding. The material lists 2.0 to 3.5 as the therapeutic range. This range provides adequate anticoagulation for higher-threshold thrombotic risks (such as certain mechanical heart valves or atrial fibrillation with additional risk factors) while keeping bleeding risk within a manageable level. The lower limit ensures enough anticoagulation, and the upper limit helps prevent thrombosis without pushing bleeding risk too high. Values below 2.0 would be under-anticoagulated, increasing clot risk; values above 3.5 raise bleeding risk for most patients unless there’s a specific clinical reason. The other ranges are either too low or too high for standard therapy, which is why 2-3.5 is the listed therapeutic range in the material.