1. Management of Patients Taking Anticoagulants Darwin Deen, MD, MS

2. References Booth SL Summa MA. Vitamin K: A Practical Guide to the Dietary Management of Patients on Warfarin. Nutrition in Clinical Care 1998;1(3)117-25. Couris RR et.al. Development of a Self- Assessment Instrument to Determine Daily Intake and Variability of Dietary Vitamin K. J Am Col Nutr 2000;19(6)801-6.

3. Learning Objectives Assist practitioners in managing their patients on chronic anticoagulant therapy to maintain consistent Vitamin K intake and stable INR values. Provide patient education regarding Vitamin K levels in common food items.

4. Rationale Coumadin is commonly prescribed to those patients who need chronic anticoagulation. Hospitalizations for excessive or inadequate anticoagulation are common. Physicians can assist their patients to maintain adequate anticoagulation by utilizing tools that help patients identify sources of dietary Vitamin K.

5. Role of Coumadin Coumadin is the brand name for crystalline warfarin sodium. Warfarin was initially developed for use as a rat poison. It selectively inhibits Vitamin K metabolism in the liver thus interrupting the clotting cascade of Vitamin K dependent clotting factors.

6. Treatment of Elevated INR Simply withholding the dose of warfarin will be effective but may take up to 1 week. Doses of 1-10 mg of phylloquinone (Vit K) are commonly used to reverse the effects of warfarin within hours (IM or po). Doses as low as 0.5 mg have been shown to be effective.

7. Dietary Phylloquinone RDA is 65-80 micrograms per day. Average daily intake is 60-200 mcg/d. Intake can increase to 600-2500 mcg/d with green vegetable intake. Patients treated with coumadin should be encouraged to keep their intake of Vitamin K fairly constant.

8. Food sources of Vitamin K The greener the plant, the greater the Vit K content: > 300 mcg/serving: –Kale, spinach, collard greens > 200 mcg/serving: –Brussel sprouts, endive, turnip & mustard greens > 100 mcg/serving: –Soy beans, tofu, scallions >50 mcg/serving: –Broccoli, asparagus, coleslaw, lettuce

9. Other Considerations These supplements may be good for some patients but for patients on coumadin may be “too much of a good thing,” and increase bleeding risk: –Garlic and Ginko Biloba have mild anticoagulant effects. –Fish Oil reduces platelet aggregation –Vitamin E reduces platelet aggregation and when administered with fish oil may reduce fibrinogen levels. –Weight loss may reduce fibrinogen levels in obese patients & reduce clotting function.* –Alcohol reduces fibrinogen levels. »* Lindahl B et al J Intern Med 1999;246:105-12.

10. Suggestions Physicians should advise their patients about the dietary sources of Vitamin K and encourage patients to attempt to maintain a stable intake of Vit K containing foods. Because vegetables are important sources of nutrients, avoiding Vit K containing foods is not recommended. If patients frequently have alterations in INR, consider referring them to a dietitian.