Work out warfarin dose adjustment instantly with clear inputs, formula shown and shareable results.
Applies the conventional 10 to 20 percent weekly dose adjustment bands used in warfarin nomograms once the INR sits outside the target range.
Weekly dose adjustment
Adjusted weekly dose = current weekly dose x (1 + percentage change), with 10-15% steps for modest deviations and dose omission above INR 5
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
Warfarin has a long half-life, so spreading a small change across the week avoids large swings.
Usually within 4 to 7 days of a dose change, sooner if the INR was far outside range.