Which INR value is considered therapeutic for many conditions on warfarin?

Which INR value is considered therapeutic for many conditions on warfarin?

• A. 1-2
• B. 2-3
• C. 3-4
• D. 4-5

Answer: (B)

Warfarin therapy is guided by the international normalized ratio (INR), which illustrates how long blood takes to clot compared with normal. For most conditions treated with warfarin, the goal is an INR about 2.0 to 3.0. This range provides enough anticoagulation to prevent thromboembolism while keeping bleeding risk reasonably low. Values around 1.0–2.0 are not sufficient for these indications, while INRs in the 3–4 or 4–5 range increase bleeding risk and are not the standard target except in special circumstances (such as certain valve situations). Higher targets may be used only in specific clinical scenarios, but 2–3 is the typical therapeutic range for many conditions.

Warfarin therapy is guided by the international normalized ratio (INR), which illustrates how long blood takes to clot compared with normal. For most conditions treated with warfarin, the goal is an INR about 2.0 to 3.0. This range provides enough anticoagulation to prevent thromboembolism while keeping bleeding risk reasonably low. Values around 1.0–2.0 are not sufficient for these indications, while INRs in the 3–4 or 4–5 range increase bleeding risk and are not the standard target except in special circumstances (such as certain valve situations). Higher targets may be used only in specific clinical scenarios, but 2–3 is the typical therapeutic range for many conditions.