Hematology and Oncology Book

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Coumadin ProtocolAka: Warfarin Protocol

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  1. See Also
    1. Coumadin
    2. Coumadin Drug Interactions
    3. Coumadin Protocol for the Perioperative Period
  2. Protocol: Starting Coumadin in elderly inpatients
    1. General
      1. Safe (no patient had an INR >4)
      2. Therapeutic INR achieved within 6-7 days
    2. Initial Dose: 4 mg daily for first 3 days
    3. Dosing protocol after day 3 based on daily INR
      1. INR <1.3: Warfarin 5 mg
      2. INR 1.3-1.4: Warfarin 4 mg
      3. INR 1.5-1.6: Warfarin 3 mg
      4. INR 1.7-1.8: Warfarin 2 mg
      5. INR 1.9-2.4: Warfarin 1 mg
      6. INR >2.4: Hold Warfarin, check INR daily
    4. References
      1. Siguret (2005) Am J Med 118:137
  3. Protocol: Starting Coumadin in general patients
    1. Pointers
      1. Loading Warfarin dose is not needed
    2. Indications for starting with concurrent Heparin
      1. Thrombophilic state (e.g. known Protein C Deficiency)
      2. Thromboembolism
    3. Indications for starting Warfarin without Heparin
      1. Chronic stable Atrial Fibrillation
    4. Starting dose of Warfarin
      1. Usual: 5 mg PO qd (anticipate therapeutic by day 4-5)
      2. High Dose: 7.5 to 10 mg qd
        1. If urgency to reach therapeutic level
        2. Study: 10 mg start was therapeutic 1.4 days earlier
          1. Kovacs (2003) Ann Intern Med 138:714
      3. Low dose: 2.5 mg PO qd
        1. Elderly
        2. Liver disease
        3. High risk of bleeding
    5. Protocol
      1. Monitor daily ProTime with INR
      2. Stop Heparin when 2 consecutive INRs therapeutic
      3. Monitor INR 2-3 times per week for 1-2 weeks
      4. Monitor INR every 2-4 weeks when stable
    6. INR 2.2 to 2.3 associated with lowest overall mortality
      1. Oden (2002) BMJ 325:1073
  4. Protocol: Adjust Coumadin (based on INR 2 to 3)
    1. See Coumadin for other target INR indications
    2. INR less than 2
      1. Increase weekly Coumadin dose by 5 to 20%
    3. INR 3 to 3.5
      1. Decrease weekly Coumadin dose by 5 to 15% or
      2. Maintain same dose and recheck in 7 days
        1. Banet (2003) Chest 123:499
    4. INR 3.6 to 5.0
      1. Consider withholding one Coumadin dose
      2. Decrease weekly Coumadin dose by 10 to 15%
    5. INR 5.0 to 10.0
      1. Withhold 1 to 2 Coumadin doses
      2. Decrease weekly Coumadin dose by 10 to 20%
      3. Indications for Vitamin K
        1. Risk of bleeding: Vitamin K 1 to 2.5 mg PO x1 dose
        2. Surgery in 24 hours: Vitamin K 2 to 4 mg PO x1 dose
    6. INR exceeds 10.0
      1. Hold Warfarin
      2. Vitamin K 3 to 5 mg PO x1 dose
      3. Monitor INR daily and consider repeating Vitamin K
      4. Anticipate significantly lower INR within 24-48 hours
    7. Serious or Life-threatening bleeding (esp. INR >20)
      1. Replace Clotting Factors (first-line)
        1. Fresh Frozen Plasma (FFP) 15 ml/kg
      2. Reverse Warfarin effect
        1. Vitamin K 10 mg by slow IV infusion
        2. Anticipate Warfarin resistance after dose
        3. Avoid in valve replacement
        4. Anticipate 16 hour delay in effect
          1. Consider repeat INR at that time
          2. Consider repeating Vitamin K at 12 hours
      3. Other
        1. Prothrombin Complex Concentrate (PCC) 50 U/kg
  5. Dosing Adjustment: Decreased Dosing
    1. Decrease Dosing by 20% (27.5 mg per week)
      1. Coumadin 2.5 mg PO on Monday, Wednesday, Friday
      2. Coumadin 5 mg PO all other days
    2. Decrease Dosing by 15% (30 mg per week)
      1. Coumadin 2.5 mg PO on Monday and Friday
      2. Coumadin 5 mg PO all other days
    3. Decrease Dosing by 5% (32.5 mg per week)
      1. Coumadin 2.5 mg PO on Monday
      2. Coumadin 5 mg PO all other days
  6. Dosing Adjustments: Standard Dosing
    1. Coumadin 5 mg PO qd (35 mg per week)
  7. Dosing Adjustments: Increased Dosing
    1. Increase Dosing by 5% (37.5 mg per week)
      1. Coumadin 7.5 mg PO on Monday
      2. Coumadin 5 mg PO all other days
    2. Increase Dosing by 15% (40 mg per week)
      1. Coumadin 7.5 mg PO on Monday and Friday
      2. Coumadin 5 mg PO all other days
    3. Increase Dosing by 20% (42.5 mg per week)
      1. Coumadin 7.5 mg PO on Monday, Wednesday, Friday
      2. Coumadin 5 mg PO all other days
  8. Resources
    1. Point of Care Guide by Mark Ebell, MD
      1. http://www.aafp.org/20050515/pocform.html
  9. References
    1. Ansell (2001) Chest 119(1 Suppl):22S
    2. Crowther (2000) Lancet 356:1551
    3. Horton (1999) :
    4. Gage (2000) Am J Med 109:484

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