IndianaHemophilia& ThrombosisCenter

Guide to Warfarin Usehelping our patients thrive

Rev 3/17©2017 Indiana Hemophilia & Thrombosis Center, Inc.

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Table of Contents

Understanding Warfarin & Oral Anticoagulation Management 5

Common Risks & Side Effects of Warfarin 9

Safety Tips for Warfarin Use 11

Pediatric Activity Recommendations During Warfarin Use 13

Understanding How Vitamin K & Warfarin Interact 15

Anticoagulation Calendar 19

How to Dose Warfarin 21

Resources & Links 22

Consent to Treatment 23

Separate Resources:

Blood Thinner Pills - AHRQ Guide

Prescription for Warfarin & Standing Order (received separately)

©2013 Indiana Hemophilia & Thrombosis Center, Inc.©2017 Indiana Hemophilia & Thrombosis Center, Inc.

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Your Name

Your initial dose of warfarin is mg once daily.

The therapeutic (beneficial) range for your INR is to .

Your next INR (blood test) is scheduled for .

You have been diagnosed with a blood clotting problem (also called coagulation). A blood clot is a thick, jelly-like mass in the blood that can stick to the walls of blood vessels and block the flow of blood. Your doctor has prescribed warfarin to help treat this problem.

Warfarin is a blood thinner (also called an anticoagulant) and its purpose is to:

» Treat or prevent a blood clot in a blood vessel (thrombosis), including a blood vessel in thelungs (pulmonary embolus).

» Treat or prevent a blood clot that often forms in people with certain heart conditions such asatrial fibrillation or in those with artificial heart valves.

» Prevent a blood clot from forming following a heart attack. Blood clots left untreated cancause a stroke.

» Lower the risk of death and of having another heart attack or stroke following a heart attack.

Warfarin is medication that must be closely monitored with blood tests. At the IHTC, warfarin therapy is managed by a thrombosis team consisting of registered nurses and physician assis-tants in collaboration with an IHTC physician.

What is warfarin and why do I need it?

Understanding Warfarin & Oral Anticoagulation Management

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The PT/INR test, usually just referred to as the INR test, is required regularly while you are tak-ing warfarin. This blood test measures how long it takes your blood to clot and is used to mea-sure the effectiveness of warfarin. PT stands for prothrombin time and is measured in a labora-tory by adding chemicals to a tube that contains your blood and measuring how long it takes for a clot to form. INR (International Normalized Ratio) is the standard system used to calculate the results of your test. Warfarin slows down the time it takes for your blood to clot and thus you should have a prolonged clotting time when compared with a normal sample.

How is my progress monitored?

INR Level 2.0 - 3.0

“thicker blood”clots faster

“thinner blood”clots slower

You will be asked to obtain your INR test on specific dates; it is very important that you keep your testing appointments. It can take the IHTC 4-10 hours to receive INR results, so it is best to have your test performed in the morning. After receiving your results, the IHTC thrombosis team will review the information and determine if your warfarin dose needs to be adjusted. Someone from the IHTC will call you with instructions, including any dose changes and the date for your next INR test. If you have not received a phone call by the end of the day of your test, please call the office at 1-877-256-8837 and leave a message stating the time and location of your INR draw. You will receive a call back as soon as possible. Office hours at the IHTC are from 8:00 am to 4:30 pm, Monday through Friday.

The effectiveness of warfarin can be influenced by a variety of factors (table 1). Some factors may reduce the effectiveness of warfarin and lead to an increased risk of developing blood clots. Other factors may work to enhance the effectiveness of warfarin and lead to an in-creased bleeding risk.

Warfarin interacts with many prescribed medications and thus it is important to inform all your health care providers that you are on warfarin therapy during any office visit or while obtaining a prescription for another medication, especially antibiotics and other anti-clotting drugs.

Warfarin also interacts with over-the-counter medications, including acetaminophen (Tylenol); aspirin; aspirin-containing ointments or creams; ibuprofen (Advil, Motrin, Nuprin); naproxen

Are there potential interactions with warfarin?

Understanding Warfarin (cont.)

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(Aleve, Orudis); the antacid drug cimetidine (Tagamet); and vitamin and herbal supplements.

Aspirin and anti-inflammatory medicines increase the time it takes for your blood to clot. These medications do not work the same way warfarin does, and taking them with warfarin can increase your risk of bleeding. You should avoid these medicines unless specifically pre-scribed by your physician. These medicines can be found in cold and allergy products, as well as pain relievers for headache, backache, muscle ache, arthritis, and menstrual cramps. Always read product labels and check with the IHTC when using over-the-counter products or a new prescription.

May reduce the effectiveness of warfarinleads to increased blood clots

May enhance the effectiveness of warfarinleads to increased bleeding

── Foods high in vitamin K (see vitamin K content table)

── Illness with fever── Increased exercise── Missing a dose── Stress

── Acetaminophen (Tylenol)── Alcohol── Antibiotics── Anti-clotting medications── Anti-inflammatory medications (Advil,

Aleve, Motrin, Nuprin, Orudis, Relafen)── Antihistamines (Tagamet)── Aspirin── Chronic diarrhea── Diet pills (fat blockers)── Not eating── Vomiting

Table 1.

Understanding Warfarin (cont.)

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» Bleeding

── Gingival (from gums), possibly from toothbrushing── Nosebleeds── Cuts that will not stop bleeding── Red or black tarry bowel movements── Red or dark brown urine── Unusually heavy menstrual bleeding or unexpected vaginal bleeding

» Unusual pain or swelling

» Bruising

── You may notice you bruise easily or have small purple spots on the skin.

» Hair loss

» Headache

» Dizziness

» Weakness

» Poor appetite

── You may feel less hungry while taking this medication.

» Mild stomach cramps

» Hemorrhage

── It’s very important to keep all appointments, office visits or lab visits, to help monitor your health care and INR results.

Common Risks & Side Effects of Warfarin

The following are risks and problems commonly associated with warfarin use. Call the IHTC if you experience any of these symptoms.

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» Take your warfarin exactly as directed and at the same time every day, preferably in the evening.

» Have your INR and other blood tests drawn on the dates requested.

» Inform all your health care providers that you are on warfarin therapy; this includes pro-viders in the Emergency Room.

» When flying stay hydrated, keep your legs moving or wear over-the-counter knee high compression hose (15-20 mmHG) to prevent venous stasis, which is slow blood flow in the legs.

» When traveling in the car for longer than one hour, take breaks every 2 hours.

» Be alert to the signs of bleeding – nausea, vomiting, diarrhea, injury or bleeding that will not stop.

» Refill your prescriptions according the IHTC’s instructions and consider using a weekly compartment pillbox to remind you to take your medications on time.

» Keep your eating habits and activities similar every day.

» Use an electric razor and a soft bristle toothbrush.

» Stay active and avoid obesity.

» Stay hydrated and avoid alcohol and caffeine.

» Maintain a healthy blood pressure.

Safety Tips for Warfarin Use

Follow these safety guidelines when taking warfarin. Not following these guidelines could be dangerous to your health.

Warfarin Do’s

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» Do not smoke.

» Do not take an extra warfarin tablet to make up for a missed dose. Instead, call the IHTC for instructions. You will need to state exactly how many doses you have missed.

» Do not take warfarin if you are pregnant or may become pregnant.

» Do not take other medications before speaking with your health care provider.

» Do not take warfarin unless specifically instructed by your health care provider.

» Do not participate in activities or sports that may result in traumatic injury or bleeding.

» Prior to any travel as you may need to have an INR test performed before you leave.

» At least 2 weeks prior to any surgery, invasive or dental procedure such as dental extrac-tion or a colonoscopy so you can be evaluated for prophylactic anticoagulation for before or after the procedure. This also gives the IHTC time to provide you with a procedure plan and schedule for anticoagulation if needed.

» Before you begin taking any new medications, including over-the-counter medicines and supplements.

» When you are sick, especially with nausea, vomiting or diarrhea, or if you are injured or have bleeding that will not stop.

» If you become pregnant as warfarin can cause birth defects.

» If you experience calf swelling, calf pain that is worse with standing or walking, and short-ness of breath, chest pain, a persistent cough or if you are coughing up blood.

» If you missed a dose of your warfarin.

Warfarin Don’ts

When should I call the IHTC?

Safety Tips (cont.)

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For toddlers and young children

» Always use approved, age-appropriate car seats in motor vehicles.

» Use gates on stairs.

» Use safety straps in high chairs and strollers.

» Play in carpeted areas.

» Avoid toys with sharp edges.

» Avoid high monkey bars and sliding boards.

For older children

» Always use approved, age-appropriate seat belts in motor vehicles.

» Use helmets and other protective equipment, i.e. when riding a bicycle.

» Avoid rough contact sports – football, hockey, lacrosse or wrestling.

» Avoid downhill skiing and snowboarding.

» Avoid activities that carry an increased risk for head trauma – rock climbing, horseback riding, diving and skateboarding.

» Participate with caution in activities such as baseball, softball and soccer.

For adult specific activity recommendations, please see your health care provider.

Pediatric Activity Recommendations During Warfarin Use

Physical activity is an important part of your overall health. You are encouraged to be active. Safety and activity recommendations are based on your age and overall abilities. The goal is to minimize your risk of trauma, especially head trauma.

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Understanding How Vitamin K & Warfarin Interact

FOOD ITEM SERVING SIZE VIT K CONTENT VIT K CONTENT BEVERAGES

Coffee n/a LowSoda 12 oz LowFruit Juice 8 oz LowMilk 8 oz LowTea (black) n/a LowWater (tap) 8 oz Low

MEATS/EGGS/CHEESECheddar Cheese 3.5 oz 2.1 LowEggs 2 large eggs 0.3 LowBeef 3.5 oz 2.4 LowChicken Breast 3.5 oz (roasted) <0.01 LowHam 3.5 oz <0.01 LowMackerel 3.5 oz 5 LowPork 3.5 oz 3.1 LowShrimp <0.01 LowTuna 3.5 oz 0.03 LowTurkey Breast 3.5 oz (roasted) <0.01 Low

CONDIMENTS/OILS/FATSSugar 1/2 cup white sugar <0.01 LowButter LowCream 8 tbsp 1 LowJell-O 1/3 cup 0.02 LowPickle (dill) 1.5 large pickle 13 LowYogurt 3.5 oz 3 LowMargarine 7 tbsp MedMayonnaise 7 tbsp High Oils (Canola, Salad, Soybean)

7 tbsp 140-190 High

Oils (Olive) 7 tbsp 28 Low

Your diet can impact the effectiveness of warfarin therapy. Specifically, foods high in vita-min K affect how warfarin works. A significant change in your vitamin K intake can result in a significant, and potentially dangerous, change in your body’s ability to form a blood clot. You can prevent this by monitoring your intake of foods high in vitamin K and keep-ing your vitamin K consumption at a consistent level every day. Use the table below as a guide while continuing to eat a normal, healthy diet.

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FOOD ITEM SERVING SIZE VIT K CONTENT VIT K CONTENT Oils (Peanut, safflower, sunflower, corn, sesame)

7 tbsp 3-15 Low

Honey 5 tbsp <0.01 LowPeanut Butter 6 tbsp 0.3 Low

BREADS/GRAINSBagel (plain) 2 bagels (100 g) 0.4 Low Bread 1-8 Low Cereal 3.5 oz Low Flour 3/4 cup 0.6 Low Oatmeal 1/2 cup 0.4 Low Rice 1/2 cup <0.01 Low Saltines 33 crackers 3.6 Low Pancakes three 4" pancakes 6.5 Low Spaghetti 3.5 oz 0.2 Low

FRUITApple (green) small apple 60 MedApple (red) small apple 20 Low Banana 1 medium 0.2 Low Blueberries 1/2 cup 6 Low Cantaloupe 2/3 cup (raw) 0.4 Low Grapes 1 cup 8.3 Low Grapefruit 1/2 medium <0.01 Low Lemon 2 medium 0.2 Low Orange 3/4 medium <0.01 Low Peach 1 medium 2.1 Low

VEGETABLESAsparagus 7 spears 80 MedAvocado 1 small MedBeans (green) 3/4 cup 16 LowBroccoli 1/2 cup 113 HighBrussels Sprouts 5 sprouts 289 HighCabbage (red) 2/3 cup MedCarrot 2/3 cup fresh boiled 15 LowCauliflower 1/2 cup 20 LowCelery 2.5 stalks 32 LowCole Slaw 3/4 cup 100 HighCollard Greens 1/2 cup boiled 440 HighCorn 2/3 cup 0.3 LowCucumber w/o peel 1 cup 2.2 LowEggplant 1 cup 2.9 Low

Understanding Vitamin K (cont.)

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FOOD ITEM SERVING SIZE VIT K CONTENT VIT K CONTENT Endive (raw) 2 cups chopped 231 HighGreen Scallion (raw) 2/3 cup chopped 207 HighKale (raw leaf) 817 HighLettuce (raw, bib, red leaf) 210 HighLettuce (iceberg, raw) 31 LowMushroom 1 1/3 cup 0.06 LowMustard Greens (raw) 1 1/2 cup HighOkra (fresh/frozen, boiled) 1/2 cup 40 MedOnion (white) 2/3 cup chopped 0.3 LowParsley 1 1/2 cup raw leaf 540 HighPeas (green, cooked) 1/2 cup 24 LowPepper (green, raw) 1 cup chopped 2.5 LowPotato w/skin 1/2 potato baked 1.1 LowPumpkin LowSauerkraut 1/2 cup canned 13 LowSpinach (raw leaf) 1/2 cup boiled 360 HighTomato 1 red tomato raw 3 LowTurnip Greens (raw) HighWatercress (raw) 3 cups 250 High

Vitamin K content is measured in ug/100 gm.

Understanding Vitamin K (cont.)

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Anticoagulation Calendar

SUNDAY MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY

Date: INR Result: Dose: Recheck INR:

SUNDAY MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY

Date: INR Result: Dose: Recheck INR:

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How to Dose Warfarin

Follow these instructions to dose your warfarin using the 1 mg (pink) and 5 mg (light orange or salmon) tabs. 1 mg and 5 mg tabs are routinely prescribed when starting on anticoagulation therapy. You can make any dose using these tabs. Always read prescription labels and make sure you know which strength of warfarin you are currently taking.

Your dose is:

Number of 1 mg tabs:

Number of 5 mg tabs:

Once you have become stabilized on a dose, other mg tabs may be prescribed to make taking your medication easier. Remember you will have co-pays for each mg tab prescribed.

Warfarin comes in the following strengths: 1 mg, 2 mg, 2.5 mg, 3 mg, 4 mg, 5 mg, 6 mg, 7.5 mg, and 10 mg tablets. Review examples doses below.

TOTAL DOSE COMBINATIONS TO MAKE TOTAL DOSE

3 mg daily dose 1 mg tab + 2 mg3 mg tab

4 mg daily dose 2 mg tab + 2 mg4 mg tab

4.5 mg daily dose 4 mg tab + 1/2 of 1 mg tab2 mg tab + 2.5 mg tab

6.5 mg daily dose 4 mg tab + 2.5 mg tab3 mg tab + 3 mg tab + 1/2 of 1 mg tab

7 mg daily dose5 mg + 1 mg tab + 1 mg tab4 mg tab + 3 mg tab5 mg tab + 2 mg tab

7.5 mg daily dose 7.5 mg tab5 mg tab + 1/2 of 5 mg tab

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Resources & Links

» http://www.drgourmet.com - information regarding the vitamin K content of foods

» http://www.ihtc.org/patient/blood-disorders/clotting-disorders/coumadin-interactions-with-food/ - further information about warfarin and eating foods with vitamin K

» http://www.ihtc.org/patient/blood-disorders/clotting-disorders/ - overview of clotting disorders and blood clots in veins

» http://www.drugs.com/drug-interactions/warfarin - information about potential drug interactions with warfarin

» http://www.ihtc.org/patient/blood-disorders/clotting-disorders/clinics/ - details about the IHTC’s anticoagulation clinics

» http://www.ahrq.gov/consumer/btpills.htm - guide to using blood thinner pills safely

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Consent to Treatment

Patient Portion

Heath Care Provider Portion

By signing the final page of this form, you understand and agree to the following expectations and give your consent to Dr. _____________ and his/her colleagues to prescribe warfarin:

── You must have regular blood tests while taking warfarin. Missed blood tests can result in hemorrhage (bleeding) and could lead to death. You must travel to the IHTC for appointments and regular blood tests.

── If you do not show up for your blood tests, your health care provider may choose to end the provider-pa-tient relationship. This means you would need to find another provider to care for you.

── It is important to follow all the doctor’s guidelines, including those regarding diet. ── You must tell the doctor or nurse about all of the prescription medicines you are taking in addition to any

over-the-counter drugs or supplements, meaning any medication that does not require a prescription. ── You have been informed of the risks, likely results, alternatives, and problems that can happen while taking

warfarin.── All your questions have been answered by your health care provider.

Because of my special health problem, these extra risks have also been explained to me:

I have the following allergies:

I prove with my signature below that my health care provider has discussed all of the facts in this form with me, that I was given the opportunity to ask questions, and that all of my questions were answered.

I confirm with my signature that I have given the patient three (3) pages of educational material and have dis-cussed with the above-named patient the risks, likely results, other choices, and possible problems of warfarin. The patient has had the chance to ask questions, all questions have been answered, and he or she has ex-pressed understanding. Thus informed, the patient has asked that warfarin be prescribed for him or her.

Signature of patient or responsible party

Witness

Date & Time

Date & Time

Signature of patient or responsible party

Witness

Date & Time

Date & Time

©2017 Indiana Hemophilia & Thrombosis Center, Inc.

IndianaHemophilia& ThrombosisCenter

8326 Naab Road, Indianapolis, IN 46260 | Tel: 317-871-0000 | Toll Free: 1-877-256-8837 Fax: 317-871-0010 | www.ihtc.org