Warfarin reversal

Background

1. Vitamin K
   1. PO route for vit K is preferred to subq route due to superior efficacy
   2. IV route carries rare but serious risk of anaphylaxis
      1. Only give for pts with:
         1. Life-threatening bleeding
         2. INR >20
         3. Symptomatic pts poisoned by suicidal ingestion of warfarin or rodenticide

Excessive Anticoagulation

INR < 5 No Bleeding

1. Lower dose or omit one dose
2. Resume at lower dose once INR therapeutic

INR 5-9 No Bleeding

1. Hold next 1-2 doses
2. Vit K 1-2.5mg po (only if pt is at high risk for bleeding)
   1. Age >75yr
   2. Concurrent antiplatelet drug use
   3. Polypharmacy
   4. Liver or renal disease
   5. Alcoholism
   6. Recent surgery
   7. Trauma
3. Resume at lower dose once INR therapeutic

INR > 9 No Bleeding

1. Hold warfarin
2. Vit K 2.5-5mg po
3. INR will decrease in 24-48h

Life-Threatening Bleeding

1. Hold warfarin
2. Give Prothrombin complex concentrate or factor VII
3. Vitamin K
   1. Give if PCC nor factor VII are available
   2. 10mg slow IV push (may repeat in 12hr if INR still elevated)
   3. May induce unwanted thrombosis and/or overcorrection
4. FFP
   1. Administer 10-15mL/kg (typically 3-4units)

See Also

Warfarin (Coumadin)

Source

Tintinalli