Download Coumadin vs. Heparin

Warfarin Sodium
Heparin
Names
Coumadin, Jantoven
Hep-Lock, Hepflush, Vasceze,
Monoject, PosiFlush
Indications
Prophylaxis for clots
associated with: A-fib, MI,
prosthetic cardiac valves, PE,
venous thromboembolism
DIC, cardiac operation, venous
thromboembolism, prophylaxis for
clots associated with: A-fib, PE,
arterial catheter-related thrombosis,
venous catheter occlusion, acute
coronary syndrome, acute STEMI,
hemodialysis, inflammatory bowel
disease, chronic interstitial cystitis,
percutaneous coronary
intervention, phlebitis, unstable
angina, prosthetic valve
endocarditis
Dosing
2-10 mg, varying to maintain
target INR
4,000-10,000 units every 4-8 hours
to maintain target aPPT
Contraindications
Anesthesia, aneurisms, blood
dyscrasias, eclampsia/preeclampsia, any condition
which causes bleeding or has
the potential for uncontrolled
bleeding, traumatic surgery,
bacterial endocarditis,
pregnancy
Active or uncontrolled bleeding
(except DIC), thrombocytopenia,
neonates/infants/pregnancy/nursing
– do not give preps preserved with
benzyl alcohol
Precautions
Prolonged therapy, anemia,
age >65, history of highly
variable INRs, HTN, renal
impairmentDM, diarrhea, eye
surgery, hepatic disorders,
indwelling catheter use,
disturbances of intestinal flora,
poor nutritional state,
steatorrhea, vasculitis, vitamin
K deficiency, increased vitamin
K intake
Age >60, bacterial endocarditis,
bleeding disorders, GI ulceration,
history of heparin resistance,
history of heparin-induced
thrombocytopenia or thrombosis,
hepatic disease, severe
hypertension, menstruation,
neonates and infants weighing <10
kg, major surgery, continuous tube
drainage of stomach or small
intestine
Adverse effects
Bleeding, alopecia, cholesterol
embolus syndrome, tissue
necrosis/gangrene,
hypersensitivity
Thrombocytopenia, increased
ALT/AST levels, hemorrhage,
heparin-induced thrombocytopenia
with or without thrombosis,
hypersensitivity, non-traumatic
spinal subdural hematoma
Pharmokinetics
Half-life: 1 week
Half-life: 1.5 hour
Highly protein bound
Extensive protein binding to LDL,
globulins, and fibrinogen
Mechanism of Action
Inhibits the synthesis of
vitamin K-dependent clotting
factors (2, 7, 9, and 10) and
the anticoagulant proteins C
and S.
Inhibits clotting at various points in
the coagulation system.
Administration
Oral
Injection (for IV only):
Reconstitute with sterile
water. Slow bolus over 12 minutes in peripheral
vein. Use reconstituted
solution within 4 hours, do
not refrigerate
Intermittent IV injection, IV infusion,
or deep subQ.
Avoid IM administration r/t
hematoma formation.
Do not use Heparin Lock Flush
Solution for anticoagulation
therapy. Consider benzyl alcohol
load when using benzyl alcohol
products. Invert IV solutions at
least 6 times to prevent pooling.
Monitoring
PT/INR. In general, target INR
is 2-3. Initially, INR daily until
stabilized, then every 1-4
weeks.
aPTT. The target aPTT is 1.5 to 2
times normal. Initially, check aPTT
leels every 6 hours until stable,
then every day at the same time.
Periodic hematocrit, platelets, stool
occult blood,
Antidote and Toxicity
Vitamin K1 (phytonadione)
Protamine sulfate
TOXICITY:
INR <5.0 w/ no significant
bleeding: lower dose or omit
the next dose.
TOXICITY:
Treatment is symptomatic and
supportive
INR 5.0-9.0 w/ no significant
bleeding: omit next 1-2 doses
and/or oral vitamin K.
Mild-Moderate: IV fluids and
vasopressors as needed
Severe: protamine sulfate, fluids,
transfusions, vasopressors,
INR >9.0 w/ no significant
bleeding: hold doses and give
oral vitamin K.
SERIOUS BLEEDING: hold
doses and give vitamin K by
slow IV infusion along with
fresh frozen plasma,
prothrombin complex
concentrates, or factor VII until
bleeding is controlled.
Clinical Teaching
Report signs/symptoms
hemorrhage, tissue necrosis,
or hepatitis. Bleeding
precautions. Avoid alcohol.
Numerous drug-drug
interactions. Avoid cranberry
products. Consume a
consistent amount of vitamin
K. Vitamin K foods.
Report signs/symptoms bleeding/
hemorrhage, rotate injection sites,
avoid aspirin-containing products,
call if dose is missed.
When d/c-ing heparin and beginning Coumadin, sample INR at least 5 hours after last heparin
bolus, 4 hours after discontinuing continuous IV heparin infusion, 24 hours after last subQ
heparin injection. Monitor for signs and symptoms of necrosis or gangrene.