Coumadin/Warfarin
Minimizing risk
and
Optimizing Safety
National Patient Safety Goal 3
JCAHO
Anticoagulation therapy poses risks to patients and often
leads to adverse drug events due to complex dosing,
requisite follow-up monitoring, and inconsistent [patient]
compliance. The use of standardized practices for
anticoagulation therapy that include [patient] involvement
can reduce the risk of adverse drug events associated
with the use of heparin (unfractionated), low molecular
weight heparin, and warfarin.
The incidence of major bleeding for patients on Coumadin
is
20%
Elements of Performance
• The hospital uses approved protocols for the initiation
and maintenance of anticoagulant therapy appropriate to
the medication used, to the condition being treated, and
to the potential for medication interactions.
• For patients starting on warfarin, a baseline International
Normalized Ratio (INR) is available, and for all patients
receiving warfarin therapy, a current INR is available and
is used to monitor and adjust this therapy.
• The hospital provides education regarding anticoagulant
therapy to prescribers, staff, patients, and families.
Why do we need a protocol?
83 y o F presents to the hospital with new onset atrial fibrillation. Her
CHADS2 score is 4, so she is started on warfarin.
First MD orders warfarin 5 mg daily
Next MD orders warfarin 10 mg X 1, unaware of first order
Patient receives 15 mg PO warfarin on Day 1 without a baseline INR
INR on Day 2 is 1.2 and patient receives 5 mg warfarin
INR is not checked on Day 3 but patient continues to receive daily 5
mg dose of warfarin….
You can see where this is going!
Pharmokinetics
• Interferes with synthesis of Vitamin K dependent clotting factors II, VII, IX and X
• Absorbed through GI tract
• Activity: Peaks in 1.5 - 3 days
Duration 2- 5days
• Half-life: 1-2.5 days
• Metabolized in the liver
• Excreted through urine and feces
Coumadin affects
the intrinsic
coagulation
pathway preventing
clotting
Coumadin Indications
• Prophylaxis of venous thrombosis
(high risk surgery)
• Treatment of venous thrombosis
• Treatment of PE
• Prevention of systemic embolism
• AMI (to prevent systemic embolism)
• Tissue heart valves
• Atrial Fibrillation
Goal INR for these indications is
2-3 is recommended
Goal INR for these orthopedic patients is
2-2.5 is recommended
INR Values and DVTs
Contraindications
• Pregnancy
• Bleeding tendencies/
blood dyscrasias
• Recent/contemplated
surgery
• Threatened abortion
• Spinal puncture/
Epidural
Lab Monitoring
• Regular monitoring INR
• Repeat INR Daily until therapeutic
for 2 consecutive days then Q48hrs
until discharge
• Goal INR 2-3 for protocol indications.
• Other indications may have goal of
2.5 to 3.5
• Standard dose time at MAH is 1800 to
allow lab results
WHERE CAN MY PATIENT GO TO GET
THEIR INR DRAWN?
Dietary Considerations
•
•
•
•
Amount of vitamin K in foods affects therapy
Maintain a consistent amount of vit K in your diet
Avoid drastic changes in your dietary habits
Adding large amounts of these food items
will  vitamin K in the body:
– margarine, canola oil, olive oil, mayonnaise
– broccoli, Brussels sprouts, kale, endives
cucumbers,
– kiwi, blueberries
– sauerkraut, soybeans, dill pickle
– beef and pork liver
– cashews
Other things that can affect
Anticoagulation
Garlic
Ginkgo Biloba
Anticoagulation affect
Green tea
Alcohol: can affect liver function which is the site
of warfarin/coumadin metabolism
Drug/Drug Interactions
Drugs that may INCREASE anticoagulant
effect or risk of bleeding:

Amiodarone***








Cimetidine (Tagamet)
Levothyroxine (Levoxyl)
Stomach remedies (Prilosec)
Laxatives (Sennakot)
Phenytoin (Dilantin)
Quinidine
Quinine
Pain relievers (Motrin)
Anticoagulant
effect
**** Requires a 50% reduction in warfarin/coumadin if new to therapy
Drug/Drug Interactions





Anti-infectives:
Fluconazole (Diflucan)
Erythromycin
Fluoroquinolones
Metronidazole (Flagyl)
TMP-SMX (Bactrim)
Anticoagulant
effect
Drug Interactions





May DECREASE anticoagulant effect:
Barbiturates
Carbamazepine (Tegretol)
Anticoagulant
Cholestyramine (Questran) effect
Rifampin
Vitamin K
Side effects:
• Bleeding: Assess any of the following
symptoms as they may indicate internal
bleeding or INR > 3:
–
–
–
–
–
–
minor gums bleeding
nosebleeds
headache
joint pain
nausea/vomit
melena
CPOE Order or Order Set
If you try to order Warfarin for
a patient who has not had an
order for 30 days, you will get
a prompt to ask you to
consider discarding this order
and ordering the Warfarin
initiating protocol
This is the Warfarin
initiation protocol
Warfarin Protocol
provides decision
support
This is to be used
for patients:
* new on Coumadin
* for the indications
listed
* with goal INR of 2-3
Normogram indicates for each
day depending on what the
INR is what the dose should
be or what the dose should be
compared to the previous
day’s dose
Prompts for baseline INR
and daily INRs
Processing the Protocol Order
Date
10
/13
/09
Medication
Coumadin per
protocol
 One time med
sheet
Time Date
Date
Date
Date
Date
18
IF CPOE Order: place paper order set in MD Order section of
chart so MDs have the nomogram
MD will order subsequent orders as one time meds. Document
dose administration on One Time Medication Sheet and
Coumadin Worksheet
To be placed in Medication
Books and document dose
administered daily
Give to patient at discharge
Warfarin Protocol Flowsheet
Date
10/13
Day of
of therapy
1
Time
1800
10/14
2
1800
10/15
3
1800
PT
INR
Dose
RN signature
1.2
5mg
K Murphy RN
1.4
5mg
D Morrison RN
2.3
2mg
D Devanna RN
New Patient Education Brochure
New Brochure from the
Agency for Healthcare
Research and Quality
Give to all patients on
Coumadin
Anticoagulant Risk and Falls
Anticoagulants place a patient at additional RISK OF HARM
Take note if patient is at RISK FOR FALL
FALL RISK + ANTICOAGULANTS =
POTENTIAL FOR LIFE THREATENING BLEEDING
Use Fall Mats
if High Risk for
falls and on
anticoagulants
Patient Teaching to prevent
bleeding
Care when using sharp objects
– Use electric razor
– Use soft toothbrush
– Use waxed dental floss
– No toothpicks
– Avoid bare feet
Patient Education
From the Caregroup Portal:
Click on Micromedex
Click on Carenotes system
Type in Coumadin
Select tablet
Select English or Spanish
PRINT
Provide patient with
this drug information
sheet as well
Case Study
Mr M is admitted to SDU with uncontrolled Atrial Fibrillation.
He is initially started on Heparin drip and Metropolol for rate
control. His heart rate is now controlled and is being transferred
to South 4 to convert to Coumadin
The Coumadin Protocol is initiated
Baseline INR is 0.8
What is the dose this patient should receive on Day 1?
5 mg
Day 2
The INR is 1.2 Your dose for the day should be?
5 mg
Day 3
The INR is 1.4 Your dose for the day should be?
7.5mg
Day 4
The INR is 2.2 Your dose for the day should be?
7.5mg
Day 5
The INR is 3.1 your dose for the day should be?
6mg