Warfarin and Dietary Interactions: Developing a Food and Drug Interaction Program

1. Warfarin and Dietary Interactions: Developing a Food and Drug Interaction Program Rehana Jamali, Pharm.D. Associate Director, Pharmacy Services Brookdale Hospital and Medical Center Brooklyn NY May 2, 2009

2. Objectives • Explain the importance of dietary interactions in managing warfarin therapy • Describe the steps involved in developing a food drug interaction program and defining program outcomes

3. Outline • Warfarin and dietary interactions • BHMC: • Food and Drug Interaction Program • Measures: • Food and Drug Interaction Audit

4. Warfarin • Pharmacology • Interfere with cyclic interconversion of vitamin K and its 2, 3 epoxide (vitamin K epoxide) • Vitamin K coagulation factors: II, VII, IX and X • Require У-carboxylation for their procoagulant activity • Treatment with warfarin results in hepatic production of partially carboxylated and decarboxylated proteins with reduced coagulant activity Vit KH2 Vit KO Vitamin K reductase (relatively resistant) Vitamin K epoxide reductase (sensitive) 7th ACCP conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines, Chest 2004; 126; 204-233

5. Vitamin K • Vitamin K: essential co-factor for coagulation factors • Dietary vitamin K • Vitamin K intake > 250 micrograms/day - decreases warfarin sensitivity • Decreased Vitamin K intake: 80% decrease intake increased INR 30% • For each increase in 100 micrograms of vitamin K intake, the INR would be reduced by 0.2 • Dose response of vitamin K on the effect of warfarin anticoagulation • dietary intake of vitamin K 65-80 mcg/day is most acceptable practice Rohde LE et al. Current opinion in clinical nutrition and metabolic care; 2007;10(1):1-5

6. Warfarin and Dietary Interactions • Dietary Vitamin K • Derived by phylloquinones in plant material • Act by warfarin-insensitive pathway • Increased intake • reduce anticoagulant response by increasing clotting factor synthesis– reduce INR • Consumption of green-leafy vegetables, vitamin K containing supplements (weight reduction diets), vitamin K supplements • Reduced intake • Prolong the INR – increase risk of bleeding • Level I evidence: • Inhibition of anticoagulant effect of Warfarin: High vitamin K content food/enteral feeds 7th ACCP conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines, Chest 2004; 126; 204-233

7. Dietary Vitamin K intake • Average intake in most adults: 70 to 80 mcg/day • Daily value (DV) for vitamin K • Limit intake of food that provide more 60% of DV for vitamin K, keep INR/PT in desired range • Food high in vitamin K (> 200% DV) – limit to 1 serving/day • Kale, spinach (fresh, boiled), turnip greens (frozen, boiled), collards, swiss chard, parsley, mustard green • Food moderate in vitamin K (60 – 199%) – limit to 3 servings/day • Brussel sprouts, spinach (raw), turnip greens (raw), green leaf lettuce, broccoli, endive lettuce, romaine lettuce Drug-Nutrient Interactions Coumadin and Vitamin K. Warren Grant Magnuson Clinical Center, National Institutes of Health Drug-Nutrient Interaction Task Force.

8. Anticoagulation Safety • High risk medication – anticoagulants • Warfarin - #1 medication associated with errors in patient homes • Drugs, nutrients and herbals, disease states – alter warfarin PK/PD • The Joint Commission • Medication Management Standards MM.01.01.03 • The hospital implements its process for managing high-alert medications • National Patient Safety Goal 3E: • Elements of Performance • when dietary services are provided by the hospital, the service is notified of all patients receiving warfarin therapy and responds according to its established food/medication interaction program 2009 National Patient Safety Goals. www.jointcommission.org. Accessed October 15, 2008

9. Food and Drug Interaction (FDI) Program • Multi-disciplinary team • Pharmacy, Nursing and Dietary, IS • Drug/Nutrient Interaction Policy • Food and Drug Interaction Pamphlet • Staff education • Audit – Compliance studies

10. Drug/Nutrient Interaction Policy Pharmacist • Profiles order; receives alert of FDI in pharmacy information system • Places FDI report in patient cassette Nurse • Acknowledges alert through automated dispensing machine or medication cassette • Obtain FDI pamphlet • Use pamphlet to provide education to patient/family and document outcomes on patient/family education flowsheet Nutritionist • Receive daily Report “Medications with potential for FDI from pharmacy department • Reinforce information about the FDI and document on the patient/family education flowsheet

11. Pharmacist Profiles Warfarin order Receives FDI alert Places FDI alert in patient cassette • Nurse • Acknowledges ADM alert or • FDI alert from patient cassette • Provides Pt. Education/provides FDI pamphlet • Documents in Pt/Family Education Sheet • Nutritionist • “Medications with potential for FDI” report” • Reinforce Patient Education • Document in patient/family education flowsheet

12. FDI Pamphlet

13. Warfarin Patient Education Pamphlet • FOOD INTERACTION WITH WARFARIN • Warfarin partially stops the development of Vitamin K in the liver to prevent blood clotting. • Many foods however contain high, moderate or low amounts of Vitamin K. • Dark green leafy vegetables have very high amounts of Vitamin K. • So does that mean that you have to stop eating foods that contain Vitamin K????? • THE ANSWER IS NO!!!!! •  Just eat the same amount of food containing Vitamin K every day. •  Avoid making drastic changes in your diet. •  Tell your doctor if your food intake suddenly includes large amounts of Vitamin K.

14. Measures Drug Nutrient Interaction Compliance Study Date:_________________ Patient name:____________________ U#:___________ Unit/Room:________ Medication name: _______________________ Date/Time ordered:_____/_______

15. Outcomes

16. THANK YOU