WARFARIN (COUMADIN®)



















  • Risk factors include: hypertension, diabetes, history of TIA, and heart failure
  • Reference [1]
Annual risk of stroke (% per year) in patients with Atrial fibrillation
< 65 years
Placebo Warfarin
No risk
factors
1 or more
risk factors
No risk
factors
1 or more
risk factors
1% 4.9% 1% 1.7%
65 - 75 years
Placebo Warfarin
No risk
factors
1 or more
risk factors
No risk
factors
1 or more
risk factors
4.3% 5.7% 1.1% 1.7%
> 75 years
Placebo Warfarin
No risk
factors
1 or more
risk factors
No risk
factors
1 or more
risk factors
3.5% 12% 1.7% 4%













  • Oral Vitamin K takes 18 - 24 hours to have an effect. Intravenous Vitamin K causes the INR to fall rapidly within 4 - 6 hours after administration. The effects of subcutaneous Vitamin K are unpredictable.
  • References [12,14,20]
Adjusting warfarin based on INR
INR ≤ 0.5 below or above therapeutic range in previously stable patient
  • Continue current dose and recheck INR in 1 - 2 weeks
INR is above therapeutic range, but less than 5
  • Reduce dose or omit next dose and resume at lower dose
INR is 5 - 9
  • Omit next 1 - 2 doses
  • Restart at lower dose once INR is in therapeutic range
  • If patient is at increased risk of bleeding, may omit next dose and give 1 - 2.5 mg of Vitamin K orally
INR is > 9
  • Give 3 - 5 mg of Vitamin K orally
  • INR should fall within 24 - 48 hours
  • Monitor INR and repeat Vitamin K as necessary
Need for surgery or dental extraction within 2 - 3 days
  • Give 2 - 5 mg of Vitamin K orally
  • INR should decline within 24 hours
  • Give additional 1 - 2 mg dose of Vitamin K if INR remains high after 24 hours












  • Values are from USDA database
Foods high in Vitamin K
FOOD VITAMIN K per 30 gram serving
(micrograms)
Parsley, raw 492
Kale, cooked, boiled 245
Mustard greens, cooked, boiled 177
Spinach, cooked, boiled 148
Spinach, raw 145
Collards, cooked, boiled 122
Turnip greens, cooked, boiled 110
Swiss chard, cooked, boiled 98
Soybean oil 55
Green onions, raw 47
Brussels sprouts, cooked, boiled 42
Broccoli, cooked, boiled 42
Green leaf lettuce, raw 38
Romaine lettuce, raw 31
Broccoli, raw 30