What is the therapeutic INR range for warfarin therapy?

• A. 1-2
• B. 2-3
• C. 3-4
• D. 0.8-1.2

Answer: (B)

Maintaining the right therapeutic window for anticoagulation is essential. For most patients on warfarin, the goal is an INR of about 2.0 to 3.0. This range provides enough anticoagulation to prevent clotting (like stroke or DVT) while keeping bleeding risk acceptably low. If the INR falls below 2.0, the risk of clotting rises; if it rises above 3.0, bleeding risk increases. Some situations, such as certain mechanical heart valves, may require a slightly higher target (around 2.5–3.5), but the typical therapeutic range is 2–3. The other ranges shown are either subtherapeutic or overly anticoagulated for routine therapy. Regular monitoring and dose adjustments are key to staying within this window.