Table 3.
Condition | Description |
INR above therapeutic range but <5.0; no significant bleeding | Lower dose or omit dose, monitor more frequently and resume at lower dose when INR is therapeutic; if only minimally above the therapeutic range, no dose reduction may be required (Grade 1C) |
INR ≥ 5.0 but <9.0; no significant bleeding | Omit next one or two doses, monitor more frequently and resume at an appropriately adjusted dose when INR is in the therapeutic range. Alternatively, omit dose and give vitamin K (1 to 2 mg orally), particularly if at increased risk of bleeding. If more rapid reversal is required because the patient requires urgent surgery, vitamin K (≤ 5 mg orally) can be given with the expectation that a reduction of the INR will occur in 24 h. If the INR is still high, additional vitamin K (1 to 2 mg orally) can be given (Grade 2C) |
INR ≥ 9.0; no significant bleeding | Hold warfarin therapy and give higher dose of vitamin K (2.5 to 5 mg orally) with the expectation that the INR will be reduced substantially in 24 to 48 h (Grade 1B). Monitor more frequently and use additional vitamin K if necessary. Resume therapy at an appropriately adjusted dose when the INR is therapeutic |
Serious bleeding at any elevation of INR | Hold warfarin therapy and give vitamin K (10 mg by slow intravenous infusion), supplemented with FFP, PCC or rFVIIa, depending on the urgency of the situation; vitamin K can be repeated every 12 hours (Grade 1C) |
Life-threatening bleeding | Hold warfarin therapy and give FFP, PCC or rFVIIa supplemented with vitamin K (10 mg by slow intravenous infusion); repeat if necessary, depending on INR (Grade 1C) |
In cases of life-threatening bleeding, one probabilistic dose of vitamin K (10 mg) is proposed; there are no specified doses for prothrombin complex concentrate (PCC) or recombinant activated coagulation factor VII (rFVIIa). Note: if continuing warfarin therapy is indicated after high doses of vitamin K, then heparin or low molecular weight heparin can be given until the effects of vitamin K have been reversed and the patient becomes responsive to warfarin therapy. It should be noted that international normalised ratio (INR) values > 4.5 are less reliable than values in or near the therapeutic range. Thus, these guidelines represent an approximate guide for high INRs. FFP, fresh frozen plasma. Reproduced with permission from American College of Chest Physicians.