Anticoagulants, Antiplatelets, Thrombolytics 2 Flashcards
Warfarin (Coumadin) blocks
the liver from making vitamin k –dependent clotting factors (II, VII, IX, X)
Warfarin (Coumadin) is structurally similar to
vitamin K
Warfarin (Coumadin) has no effect on
circulating clotting factors or on platelet function-will take 3-5 days to take effect
Why do you know Warfarin (Coumadin) has multiple drug interactions
because its a highly protein bound; Half-life of 0.5 to 3 days
Warfarin (Coumadin) indications
Long-term prevention or treatment of deep vein thrombosis; Pulmonary embolism; Atrial fibrillation with embolization; Management of myocardial infarction
Warfarin (Coumadin) adverse effects
bleeding
Warfarin (Coumadin) contraindicated in
pregnancy, GI ulcers, Severe hypertension, liver, or kidney disease, Recent surgery of the eye, spinal cord, or brain
Drugs that decrease Coumadin’s effect:
estrogens, oral contraceptives, phenytoin (Dilantin), diet or nutritional supplements high in Vitamin K
Drugs that increase Coumadin’s effect:
anti-platelet drugs (aspirin, NSAIDs, plavix), cephalosporins, thrombolytics
coumadin’s antidote:
a vitamin k injection
coumadin is begun while
heparin is still being administered, overlapping 3-5 days to maintain therapeutic control of clotting.
assess pt on coumadin for
s/s of bleeding
for pt on coumadin monitor
Prothrombin Time or INR (International Normalized Ratio) during therapy to determine appropriate Coumadin level
Prothrombin Time is especially sensitive to
alterations in vitamin K-dependent factors. Without Coumadin, Prothrombin Time is 12 seconds
Goal of Coumadin therapy:
a Prothrombin Time 1.3 to 1.5 times the control
International Normalized Ratio
ensures that results from different labs are comparable; determined by using a correction factor specific to the particular thrombolplastin preparation employed for the test
Goal is for International Normalized Ratio to be
2-3 if on coumadin
Teach w/ Coumadin
Take Coumadin same time each day; Do not double dose, if a dose is missed; Keep diet consistent: Avoid foods high in Vitamin K (greens, asparagus, broccoli, cabbage, green tea); will decrease action of Coumadin; Medic Alert; Avoid alcohol
anti-amemics
Epogen (erythopoieten)
Epogen (erythopoieten) stimulates
RBC production; used to treat anemia
with Epogen (erythopoieten) there is increased risk of
seizures greatest during first 3 months of therapy
Epogen (erythopoieten) is given
subq or IV; do not shake vial; refrigerate multi-dose vial
with Epogen (erythopoieten) monitor
Hgb & Hct
Thrombolytics:
Activase (alteplase-tPA), Streptokinase
Thrombolytics MOA
dissolve thrombi; stimulate conversion of plasminogen to plasmin that degrades fibrin in clots
Thrombolytics used in treatment of
of MI (lysis of clots in coronary arteries) treatment of CVA
For those with MI, results are best when
thrombolytic therapy is started within 4-6 hrs
Thrombolytics adverse effects
bleeding
Anti-platelets:
aspirin, ticlopidine (Ticlid), clopidogrel (Plavix)
Anti-platelets MOA
present platelet aggregation and interfere with the initial phase of blood coagulation
aspirin causes irreversible ***
inhibition of cyclooxygenase, an enzyme necessary for synthesis of thromboxane A2 which is necessary for platelet activation
Anti-platelets are used to
prevent MI, stroke, thromboembolism in clients with prosthetic heart valves
Anti-platelets adverse effects
bleeding, GI bleeding/ulcers, hemorrhagic stroke
If GI bleeding occurs,
a proton pump inhibitor (pantoprazole/protonix) can reduce gastric acidity and help prevent gastric ulcers
