Warfarin and Dietary Interactions:

Developing a Food and Drug Interaction Program

Rehana Jamali, Pharm.D.Associate Director, Pharmacy ServicesBrookdale Hospital and Medical Center

Brooklyn NY

May 2, 2009

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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

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Outline

• Warfarin and dietary interactions

• BHMC:– Food and Drug Interaction Program

– Measures:• Food and Drug Interaction Audit

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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 epoxide reductase (sensitive)

Vitamin K reductase

(relatively resistant)

7th ACCP conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines, Chest 2004; 126; 204-233

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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

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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 feeds7th ACCP conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines, Chest 2004; 126; 204-233

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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.

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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

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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

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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

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Pharmacist

Profiles Warfarin orderReceives FDI alert

Places FDI alert in patient cassette

Nurse

Acknowledges ADM alert or FDI alert from patient cassette

Provides Pt. Education/provides FDI pamphletDocuments in Pt/Family Education Sheet

Nutritionist

“Medications with potential for FDI” report”Reinforce Patient Education

Document in patient/family education flowsheet

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FDI PamphletAnticoagulant

Medication: Warfarin (Coumadin®)

Interaction: Keep a consistent diet. Avoid large changes in the amount of Vitamin-K containing foods.

Reason:Taking foods rich in Vitamin-K may alter the blood thinning response of the medication.

Foods high in Vitamin-K include:

Vegetables:

AsparagusCucumber,(w/peel) Scallions Broccoli Lettuce (bid, red leaf)Mint leaves

Spinach Brussels sprouts Fried/boiled onionsCabbage (raw)WatercressTurnip greensChick peas

EndiveChiveKaleMustard greens Collard greensSwiss ChardParsley

Herbals:Tea leaves (green)

Oils:Soybean oil, Canola oil Mayonnaise

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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.

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Drug Nutrient Interaction Compliance StudyDate:_________________Patient name:____________________ U#:___________ Unit/Room:________Medication name: _______________________ Date/Time ordered:_____/_______

Policy/Procedure Yes No

“Food-Drug Interaction Pamphlet” shall be maintained in all Pharmacy, Nursing, and Food and Nutrition Services.

Upon profiling an order of a medication that belongs in the “Food-Drug Interaction Pamphlet”, an alert will automatically appear in the pharmacy information systems.

Upon accessing the ADM to retrieve the medication for administration to the patient, the nurse will need to acknowledge an alert regarding the drug/nutrient interaction.

With the medication cart, a “Medications with the potential for food drug interaction” report will be sent by pharmacy services to nursing that will list the name (s) of patient (s) and those medications that interact with nutrients (as specified in the pamphlet).

Upon exchange of the cart, nursing shall accept this report.

The nurse shall give the “Food-Drug Interaction Pamphlet” to the patient/resident and discuss the identified drug/nutrient interaction. The nurse shall document the distribution of the pamphlet and counseling on the interdisciplinary patient/resident teaching form.

The Food and Nutrition Services shall also receive a daily report (Medications with the potential for food drug interaction) from pharmacy.

The Food and Nutrition Services shall adjust the patient/resident’s diet according to the nutrients specified in the pamphlet. The dietician shall reinforce the information taught by nursing regarding the drug/nutrient interaction (s), and document counseling on the Nutritional Assessment Form/Care Plan and the interdisciplinary patient/resident teaching form.

Measures

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Outcomes

Measure Pre

May 2008 (30 cases)

Post

Feb-April 2009

(12 cases)

FDI pamphlet available Pharmacy – 100%

Dietary – 100%

PCA – 20%

100%

Alert in Rx system 100% 100%

RN acknowledge alert in ADM 100% 100%

Medication cassettes – alert 0% N/A (cartless)

RN educates patient 0% 0% (no documentation)

Dietary receives report 100% 100%

Dietary educates patient 100% (questionable) 33% (documentation )

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THANK YOU