Warfarin Safety for Nursing HomesNursing Homes

Dianne Roux-LirangeJanuary 2010

OverviewA Background – Hx of warfarinB How warfarin worksB How warfarin worksC Indications for useD Side effects - BleedingD Side effects BleedingE Bleeding is minimized with monitoringF Dose adjustment and managementF Dose adjustment and managementG When INR is OK, hemorrhage may occurH MedPass charting and F/UH MedPass, charting, and F/UI Wrap-Up

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A The History of Warfarin

Farmers’ Alarm1920s: Cattle were hemorrhaging to death

Found to be due to a contaminant in their dietS il d t l i th i f d hi h t i dSpoiled sweet clover was in their feed which contained a chemical substanceIt interfered with the coagulation process

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The History of Warfarin

Discovery of warfarin1940s: at the University of Wisconsin

Synthesized a chemical, dicumarol, A d d th t it id ti l t thAnd proved that it was identical to thenaturally occurring agent in sweet cloverThey patent the compound WARFarin, y p p ,a play on the name of their office,Wisconsin Alumni Research Foundation,

It is marketed as a rat pesticide/poison

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The History of Warfarin

FDA patent1954: Endo labs take out the first patent for human use

It is filed as Coumadin the brand name of warfarinIt is filed as Coumadin, the brand name of warfarinIt was found to be effective and relatively safe for preventing thrombosis and embolism (abnormal formation and migration of blood clots) in manyformation and migration of blood clots) in many disorders

Warfarin, the generic version of Coumadin, was filed in 1995

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B How Warfarin Works

Warfarin is an anticoagulantSubstance that “thins” the blood

Clinically used to reduce the body’s ability to form bl d l t t t bl d l tblood clots – to prevent blood clotsSeems to “thin” the blood so that cuts “won’t stop bleeding”bleedingIt disrupts the coagulation processg p

Other namesCoumadin®, Jantoven®

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How Warfarin Works

(1a)Understanding coagulation(1a)Understanding coagulation

Coagulation converts fluid bloodinto a fibrin clot at the site of injury

Normally, clot formation does not occur within a healthy,

intact blood vessel

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How Warfarin Works(1b)Understanding coagulation

Coagulation process is activated whenCoagu at o p ocess s act ated einjury/damage into the wall of a blood vessel (cells of the vascular endothelium)A b t l k tA substance leaks out

Then the vitamin K process Kicks inVitamin K is a chemical that is one of our vitamins (vitaminsVitamin K is a chemical that is one of our vitamins (vitamins are vital/essential to life/health)Vitamin K is absorbed from the digestive tract and travels to the liver to workthe liver to workK Kauses “KOAGULATION”In the liver, Vitamin K produces a clotting factorg

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How Warfarin Works(1c)Understanding

coagulationThen vitamin K process Kicks in

In the liver, Vitamin K produces PROTHROMBINVitamin K is at the top of one of the coagulation pathwaysProthrombin circulates in the blood systemA damaged cells triggers it to plug holes in the walls

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How Warfarin Works(2a)Warfarin stops clots by stopping the action stopping the action of vitamin K STOPSSTOPS

Vitamin K makes prothrombinWhen triggered, prothrombin makes clotting factorsThis leads to making fibrinFibrin with platelets form theFibrin with platelets form the clot

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How Warfarin Works

(2b)Warfarin stops clots by stopping vitamin Kvitamin K

It is classified as an anti coagulantIt is an anticoagulant known as a vitamin KIt is an anticoagulant known as a vitamin K antagonist (VKA)

It turns on the blood flow by disrupting the vitaminIt turns on the blood flow by disrupting the vitamin K pathway (one path in the coagulation process)

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How Warfarin WorksWarfarin has a delayed effect when first

startedstartedIt takes 2-3 days – compared to other drugs, this is a very long onset of action BECAUSEy gClotting factors, like Prothrombin, that have already been made by the body are still present and still making fibrin clotsNeed overlap therapy with an immediate acting

ti l t if id i d i danticoagulant if rapid response is desiredHeparin, Lovenox (enoxaparin), Arixtra (fondaparinux),

Fragmin (dalteparin)g ( p )

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C Indication for warfarin therapyIt is the most commonly prescribed

anticoagulantAbout 31 Million prescriptions dispensed in 2004

But it is a risky medication andMostly responsible for serious & life-

threatening adverse reactionsthreatening adverse reactionsNarrow Therapeutic Window Fine line between being helpful and being harmfulbetween being helpful and being harmful

Among the top 5 drugs contributing to ER visitsAmong the top 2 drugs causing hospitalizationg p g g p

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Indication for warfarin therapypyUsed for abnormal vascular conditions in

which there are inappropriate clot pp pformations in an uninjured blood vessel

Clots such asThrombus – is a blood clot. Clotting is normal with blood vessel injury but pathological otherwise.Embolism – occurs when part of a thrombus b k d t l th h thbreaks away and travels through the bloodstream. It can block the blood supply to organs.organs.

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Indication for warfarin therapyConditions

Prevention of embolism in patients:Prevention of embolism in patients:With artificial heart valvesWith atrial fibrillation to prevent strokeWith atrial fibrillation to prevent strokes/p heart attack

Prevention & Treatment of venousPrevention & Treatment of venous thromboembolism (VTE)

Deep vein thrombosis (DVT)● Prevent DVT in patients with prolonged bed rest

Pulmonary embolism (PE)

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Atrial Fibrillation

Atria of the heart are not contracting properly

Pooling of blood in the heartIncreased risk of thrombus formationo at o● May lead to stroke● Warfarin reduces risk of

strokestroke

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Venous Thromboembolism VTE

Deep vein thrombosis DVT

Thrombus develops in the deep veins

Usually in the legsSymptoms

Swelling, warmth, redness, pain, engorged superficial veins● Not all symptoms are always

present

May break away and cause PE

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Venous Thromboembolism VTEPulmonary embolism PE

Part of a clot formed in th b d ( ll i ththe body (usually in the legs) breaks off & travels to the main artery of the lungsSymptoms

Chest pain difficultyChest pain, difficulty breathing, cyanosis, rapid breathing and heart rateheart rateSome people may cough up blood (but not everyone!)

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everyone!)

Who is at Risk for VTEElder Age

Risk doubles for every d d ft th f

Vascular InjuryOrthopedic surgery

decade after the age of 50

History of VTE

Knee/hip replacementTrauma

Strongest known risk factor for DVT/PE

Limited mobility

Pelvis, hip, leg fracture

Hypercoagulable StatesLimited mobility

Prolonged bed restMajor medical illness

StatesCancer

Drugs(CHF, MI)ParalysisObesity

gBirth control pillsEstrogen replacementObesity

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D Side Effects of WarfarinBleeding!!!

Most common side effect ofMost common side effect of warfarin use

Minor bleeding occurs in 14% to g36% of patientsMajor bleeding (serious, life-th t i f t lthreatening, or fatal hemorrhage) occurs in 5% to 7.9% of patients

● Hylek EM, Seminars in Vascular Medicine 2003 and Hylek EM, Circulation 2007

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BleedingMinor bleeding is common among warfarin userseven when patients are well managed on warfarin

Small bleeding from mucous membranes while brushing teeth (friable gums)

f th ( i t i )or from the nose (epistaxis)Easy bruising – may begin with ecchymoses (purple patches)ecchymoses (purple patches)Bleeding from a small cut

May be on a nursing care plan May be on a nursing care plan for easy bruising and/or bleeding

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BleedingMinor bleeding is common among usersBut Minor becomes serious bleeding when

Gums won’t stop bleedingp gA bruise that grows for no reasonA cut that is still bleeding after 10 minutesg

Requires a nursing note in chart.

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Signs & symptoms of major bleedingMay mean internal hemorrhage, such as, gastrointestinal or cerebral,Follow procedure to place call to doctorFollow procedure to place call to doctorNursing Assessment:^Vomiting blood or gastric contents that

Patient Complaint:Vomiting blood or gastric contents that

looks like coffee grounds (hematemesis)

^Stools that are bloody or are dark and

^Severe abdominal pain^Persistent headaches

^Stools that are bloody or are dark and tar-like (hematochezia)

^Urine that is red or unusually dark ^Confusion or decreased

alertness(hematuria)

^Coughing up phlegm that is bloody (hemoptysis)

^Dizziness or weakness

(hemoptysis)24

(1) Your “Warfarin Watch” ListBleeding may be more serious

for patientsfor patients(1a) With certain conditions(1b) Who fall(1b) Who fall

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(1a) Your “Warfarin Watch” ListWatch for bleeding in certain patients

Bleeding risk is increased with patients having the following conditionshaving the following conditions

Patients also receiving concomitant antiplatelet drugs (clopidogrel (Plavix) and/or aspirin)antiplatelet drugs (clopidogrel (Plavix) and/or aspirin)Patients older than 65 yrsPatients with prior stroke renal impairment or anemiaPatients with prior stroke, renal impairment or anemia

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(1b) Your “Warfarin Watch” ListPatients who have a history of falls and/or are not

steady on their feet Aft f ll hit th h d Th I id t R t After a fall or hit on the head, The Incident Report

should have these notesYES � or NO �YES � or NO �

1-Visible bleeding? If so, severity?2-Symptoms of internal bleeding? y p g3- Symptoms of IntraCranial Hemorrhage?

If so, do first neuro-checkPatient is on warfarinWith this information, per policy, place call to doctor

● Continue FOLLOW-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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(1b) Your “Warfarin Watch” List. . . .The Incident Report should have these notes

Follow-upContinue neuro-check, if started

YES � or NO �Symptoms of bleeding that was not present before?not present before?

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E Bleeding is minimized with monitoringWarfarin therapy is proven to be effective

and safe WITH MONITORINGMonitoring involves scheduled blood tests

and reviewing results so that warfarin may be adjusted accordingly

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Bleeding is minimized with monitoring(1)Scheduled blood tests

Two blood test are available- both involveTwo blood test are available both involve measuring prothrombinBecause

When a blood vessel is damaged,

Vit i K ki k iVitamin K process kicks in,

Circulating prothrombin is activated

Leading to clot formation

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Bleeding is minimized with monitoring

(2)Scheduled blood tests(2)Scheduled blood testsProthrombin time (PT) assay

Measures the time it takesMeasures the time it takesfor prothrombin to form a clot

International Normalized Ratio (INR)International Normalized Ratio (INR)INR value is the patient’s prothrombin time as a ratio using international reference standardsratio using international reference standards

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Bleeding is minimized with monitoringFor patients on warfarin, tests results are:

prothrombin time (PT) is longerp ( ) gINR value is greater

than normalthan normal

Normal values (for patients not on warfarin):PT is anywhere between 11 0 and 13 0 seconds andPT is anywhere between 11.0 and 13.0 seconds, and value varies from lab to labINR is 1.0 (one)

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(1) INR schedules/guidesDosing is guided by two different INR

guides based ong(1a) Initiation dosing – for patients beginning VKA therapy(1b) Maintenance dosing - for chronic VKA therapy

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(1a) INR schedules/guidesWhen warfarin is started, dosingis guided by INR (per doctor’s orders)is guided by INR (per doctor s orders)

It takes 2-3 days for warfarin to take effectTo cover this delay: heparin-anticoagulants are coadministered for 4-5 days to provide coverageThis is called the “loading phase”

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(1a) INR schedules/guidesWhen warfarin is started, dosingis guided by INR (per doctor’s orders)is guided by INR (per doctor s orders)

Prescribers use a dose algorithm (a guide) to prescribe the(a guide) to prescribe the appropriate dose

Prescribers orderPrescribers order More INR tests in the first several weeksAnd then weekly until the INR is stableAnd then weekly until the INR is stableThen monthly – this is the usual scheduling of testing for patients on chronic warfarin therapy

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(1b) INR schedules/guidesFor chronic warfarin therapy, dosing is guided by INR (per doctor’s orders)dosing is guided by INR (per doctor’s orders)

The target INR for most conditions is 2.5 with an acceptable range of 2 0 to 3 0acceptable range of 2.0 to 3.0. For some patients the INR goal will be 3.0 with a range of 2.5 to 3.5 (for those with artificial heart g (valves, recurrent clots, etc.)

When INR response is stable, frequency of testing may be reduced to once every 4 weeks

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(1b) INR schedules/guidesFor chronic warfarin therapy

2.0 -------------------------3.0

INRINR

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Bleeding is minimized with monitoringWhen surgery or a procedure is scheduled for a patient on warfarinp

Per doctor’s orders:Warfarin may stopped some time before and y ppresumed sometime after

OR“Bridge therapy” may be ordered (if the risk of clotting is high) which means another anticoagulant is used to bridge the time patient is off warfarin during the peri-operative period

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F Dose Adjustment and ManagementFrequent dose changes are common, per

doctor’s orders, for these reasons:Each person responds differently to warfarin (age, liver health, CHF, fever)W f i i di t bl it i t tWarfarin is unpredictable: it interacts with other medications and foods

And the INR range is difficult to achieveAnd the INR range is difficult to achieveCompared to other drugs, the therapeutic window/range is very narrowg y

To counteract this, the doctor individualizes dosing based on INR level

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Dose Adjustment and ManagementFor chronic warfarin therapy

2.0 -------------------------3.0

INR

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Dose Adjustment and Management

(1a)Interaction with other medicationsDrugs that may prolong PT/increase INR:

ANTIBIOTICS, antifungals, H2 blockers, PP inhibitors, antidepressants, CaCblockers, antiarrythmics (amiodarone), lipid lower agents (Zocor), anticonvulsants (phenytoin Dilantin)(Zocor), anticonvulsants (phenytoin Dilantin)

Drugs that may shorten PT/decrease INR:Barbiturates, anticonvulsants(carbamazepineBarbiturates, anticonvulsants(carbamazepineTegretol)

● Continue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Dose Adjustment and Management

(1b)Interaction with other medications and supplementsand supplements

Over-the-Counter Pain RelieversSalicylates Aspirin NSAIDs: ibuprofen (Motrin Advil)Salicylates Aspirin, NSAIDs: ibuprofen (Motrin, Advil), naproxen (Aleve)

Increase bleeding risk

Herbal SupplementsGinseng, Gingko, Garlic, St. John’s Wort, & many others!others!

Some increase bleeding risk, others increase clot risk

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Dose Adjustment and Management(1c) Lists of

other di timedications

Drug interaction lists can be found:

1- from your pharmacy vendor1 from your pharmacy vendor2- in patient package insert

for Coumadin3- on the internet – see

example ofexample of www.drugs.com site for search box and lists of common drugs and 186 major interactionsmajor interactions

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Dose Adjustment and Management

(1d) It is often impossible to predict how a specific medication will affect a a specific medication will affect a patient’s INR

Always obtain a stat INR within 3-7 daysAlways obtain a stat INR within 3-7 days

When starting an antibioticWhen any change (start, stop, dosing) of any medication

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Dose Adjustment and Management(2a) Vitamin K and Interacting Foods

Sources of vitamin K is through digestionSources of vitamin K is through digestionFrom the diet and bacterial products in the large intestinePeople on warfarin can eat foods high in Vitamin K, as long as they do so consistently

Concern is about major changes in Vitamin K intakej g

Nurses on maternity units know: vitamin K shots are given to newborns to prevent bleeding – they are vitamin K deficient because the intestines haveare vitamin K deficient because the intestines have not yet been colonized with bacteria

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(2b) Vitamin K Content of Foods (see list)

Very High High Medium Low

Brussel sprouts

Chi k

Basil

B li

Green Apple

A

Fruits

A dChick peas

Collard greens

Coriander

Endive

Broccoli

Chive

Coleslaw

Cucumber (w/

Asparagus

Cabbage

Cauliflower

Mayonnaise

Avocado

Beans

Breads/grains

Carrots

Kale

Lettuce, Red Leaf

Parsley

(peel)

Canola oil

Green onion/Scallion

y

Pistachios

Squash, summer

Celery

Coffee

Corn

Spinach

Swiss Chard

Tea, Green

Watercress

Soybean oil Cucumber (w/o peel)

Dairy products

Eggs

Lettuce, IceburgWatercress Lettuce, Iceburg

Meats, fish, poultry

Pasta

Peanuts

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Dose Adjustment and Management

.

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Dose Adjustment and Management(3a)Expect dose adjustment whenINR is nontherapeuticINR is nontherapeuticWhen INR is slightly out of therapeutic range,

doctor manages the dosing byNo dose change but more frequent INR testing – expecting the INR to return to therapeutic levelsORORAdjusting the dose by 5%, 10%, 15% or 20% based on the weekly dose of warfarin

Expect an order for INR test after a dose change – may see INR effect of new warfarin dosage in 2-3 days y

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Dose Adjustment and Management(3b)Expect dose adjustment when<<INR value is out-of-target range>> <<INR value is out of target range>> and no bleeding (asymptomatic) or minor bleeding bleeding If INR increased but not > 5.0, dose may be reduced

By lowering weekly dose (* by certain %) or omitting dose(s)By lowering weekly dose ( by certain %) or omitting dose(s)i.e., if patient’s INR is 3.6, doctor will decrease dose by 15% hoping to hit an INR of 2.6 (one whole change in INR value)

If INR decreased doctor may increase doseIf INR decreased, doctor may increase doseBy increasing weekly dose (* by certain %)

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Dose Adjustment and Management(3c) Expect other med orders whenINR value is out-of-target range >>5.0 and INR value is out of target range >>5.0 and

<<10.0andandnon-life threatening bleeding

Med orders may be:Med orders may be:Stop warfarinGive antidote to reverse VKA over-coagulation● vitamin K (phytonadione Mephyton®) PO

● (note if there’s a repeat dose in 6 -12 hours) – recall vitamin K works in the coagulation process so expect that effects are not immediate (it works slowly)

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Dose Adjustment and ManagementSummary – MedexFor warfarin managementg-orders for adjustmentsIs not completed

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Dose Adjustment and ManagementSummary – MedexFor warfarin managementg-AdjustmentsPer doctor’s orders

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G When INR is OK (in the therapeutic range) hemorrhage may occurg ) g yConsider possibility of hemorrhage with a

patient whose complaints don’t patient whose complaints don t indicate an obvious diagnosis:

Anticoagulated patients,regardless of INR, are at g p grisk of major bleeding events Use your clinical skills and observe your patients for these s&s:M t i i th h t bd j i tMay present as pain in the chest, abdomen, joints, or muscle, paralysis, headache, dizziness, shortness of breath, difficulty breathing or swallowing, unexplained swelling, or weakness.Finally hypotension leading to unexplained shock

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When INR is OK, hemorrhage may occur

Laboratory tests for signs of blood lossFor anemia: complete blood count, hemoglobin and hematocrit values, S h i tSerum chemistry,For urinary tract bleeding: urinanalysis

Other meas res/testsOther measures/testsVital signs showing low blood pressure and fast heart rateheart rate For GI bleeding/hematochezia: fecal occult blood test (FOBT)

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When INR is OK, hemorrhage may occur If life-threatening bleeding

THIS IS AN EMERGENCY Follow protocol for calling doctor and transferring patient to ED

ED will institute life-saving treatments to reverse anticoagulationF h f l (FFP) d it i KFresh frozen plasma (FFP) and vitamin K (phytonadione injectable emulsion) are most frequently administeredq yCoagulation factor concentrates (i.e., prothrombin complex concentrate (PCC)) may be administered

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H MedPass, charting, and F/URoutine activities - may have standard

policy/procedures for the following)

M d P ( b / h i d i )Med Pass (may be new/changes in dosing)Check-off lab receipt for incoming INR reportsT k ff d hl i d O dTake off new orders or monthly printed OrdersFollow up phlebotomy / POC finger prick schedule

Other activitiesLab calls with an alert valueFollow up patient care (abnormal BPs or complaints)

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MedPass, charting, and F/UOn Med Run, expect - there is no

“typical” dose of warfarinEach person responds differently to

warfarin

D i di id li dDoses are individualizedFrequent dose changes are commonHigh or low INR levels are not reconciled by changing the daily dose of warfarin, but rather by altering the total weekly doserather by altering the total weekly dose

Results in crazy-wacky dosing schedules

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MedPass, charting, and F/UDosing is reconciled with INR levels by

altering the total weekly doseThe new orders may look unusual – see this example

Mr. Smith takes 5 mg daily. His goal INR is 2-3, but today his INR is 3 6 (too high!)but today his INR is 3.6 (too high!)His warfarin dose needs to be decreased

Calculate his total weekly dose (= 35 mg/week)Decrease the total weekly dose by 15% (15% equates to one whole INR change.)● 15% of 35 is 5 mg. Total weekly dose is 30 mg (=35 – 5 mg)

New orders are – 5 mg daily, except on Tuesday & Thursday take 2.5 mgThursday take 2.5 mg

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MedPass, charting, and F/UThe Dosing Game

Mrs Jones is on 2 mg/day

1 mg pink

2 mg lavender Mrs. Jones is on 2 mg/day

How many ways can we make 2 mg dose of warfarin?

2-1/2 mg green

3 mg tan 2 mg dose of warfarin?● 3 ways

● 1 tab of a 2 mg tablet● ½ of a 4 mg tablet

4 mg blue

5 mg peach g

● 2 tabs, each 1 mgAlthough the med tray is in unit-dose packets, it is a good opportunity for

6 mg teal

7-1/2 mg yellow

packets, it is a good opportunity for teaching patients who are going home on warfarin.

10 mg white (Dye Free)

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MedPass, charting, and F/U

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MedPass, charting, and F/U

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I Wrap-upWarfarin is a dangerous drug

Bleeding is a risk and patients may not complain or show symptoms of internal bleeding

Warfarin is a complicated drug regimenFrequent dose change, many drug and food interactions, narrow therapeutic window between b fi i l d h f l ff tbeneficial and harmful effects

Team work and good communication with physicians and between shifts with physicians and between shifts with everyone aware of policy and procedures is crucial to warfarin safetyis crucial to warfarin safety

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IPRO provides a full spectrum of healthcare assessment and improvement services that foster the efficient use of resources and enhance healthcare quality to achieve better patient outcomes.

This material was prepared by IPRO, the Medicare Quality Improvement Organization for New York State, under contract with the Centers for Medicare &

Medicaid Services (CMS), an agency of the U.S. Department of Health and Human Services. The contents do not necessarily reflect CMS policy.

9SOW-NY-THM6.2-10-05

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For more information

Dianne Roux-Lirange, PhD, MSRNPerformance Improvement Coordinator

M di Ph P j tMedicare Pharmacy ProjectsHealthcare Quality Improvement Program

(518) 426-3300 ext 106(518) 426-3300 ext. 106drlirange@nyqio.sdps.org

CORPORATE HEADQUARTERS1979 Marcus AvenueLake Success, NY 11042-1002REGIONAL OFFICE20 Corporate Woods BoulevardAlbany, NY 12211-2370

www.ipro.org

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