CV: Anticoagulants Flashcards
what are the 3 categories of anticoagulation meds?
anticoagulant
antiplatelet
fibrinolytic
anticoagulants prevent what in what?
clot formation in venous system
do anticoagulants prevent clot formation in the venous or arterial system?
venous system
what meds prevent venous thrombosis?
anticoagulants
antiplatelet meds prevent what?
clot formation
do anti platelets prevent clot formation in the venous or arterial system?
arterial system
what do fibrinolytics do?
facilitate destruction of blood clots to re-establish blood flow
what are the 4 different anticoagulants?
1) heparin
2) Coumadin
3) direct thrombin inhibitors
4) factor Xa inhibitors
what is the primary indication for anticoagulants?
DVT
anticoagulants are administered for acute Rx of _____ ______ and ________
venous thrombosis and thromboembolism (VTE)
what are other indications for anticoagulants?
individuals at high risk for developing VTE following:
- surgical procedures (jt replacement, mech heart valve)
- CV events (MI, a fib, ischemic CVA)
- medical conditions causing dec activity/periods of immobility
can anticoagulants be given prophylactically?
yes
what is the primary drug fro initial Rx for clots in the venous system?
unfractionated heparin
what does unfractionated heparin do?
activates antithrombin protein to bind to clotting factors (thrombin, IXa, Xa) to render them inactive
t/f: unfractionated heparin are large sugar like molecules that are poorly absorbed by the GI tract, therefore administered IV as an infusion or SQ injection
true
is heparin taken orally or by injection?
injection
fractionated (LMWH) Heparein usually ends in what?
-parin
what kind of meds are Enoxaparin (Lovenox), Daltepin (Fragmin), and Tinzaparin (Innonep)?
fractionated (LMWH) Heparin
how is fractionated (LMWH) Heparin administered?
SQ injection
t/f: therapeutic effects of unfractionated heaprin are seen instantly
true
how many times a day is fractionated vs no fractionated heparin administered?
unfractionated=2x/day
fractionated=1x/day
are there less adverse effects with fractionated or unfractionated heparin?
fractionated
fractionated heparin is less likely to lead to _____ and _____
hemorrhage, HIT
t/f: fractionated heparin decreased the need for lab monitoring
true
what is the primary drug for long term Rx and/or prevention of DVT and PE and for maintanance of a mechanical heart valve?
Warfarin (Coumadin)
warfarin (coumadin) is a ______ antagonist
vit k
warfarin (coumadin) interferes with metabolism of what in the liver?
vit k
t/f: warfarin(Coumadin) impairs several clotting factors (II, VII, IX, X)
true
overtime, with the use of warfarin (Coumadin), levels of clotting factors in circulation____, decreasing blood coagulability
decreases
how is warfarin(Coumadin) administered?
orally
what is the lag time of warfarin(coumadin)?
several days until the therapeutic effects are achieved
t/f: the therapeutic effects of warfarin(Coumadin) are seen instantly
false, they take several days
what is given at the same time when warfarin(coumadin) is initiated?
heparin
t/f: you must monitor therapeutic levels of warfarin (Coumadin) using standardized lab tests
true
what are the standardized lab tests to measure levels of anticoagulants in the blood?
PT
aPTT
INR
when warfarin(coumadin) is utilized to maintain a mechanical heart valve, the pt must keep INR therapeutic levels in the acceptable range of ____ to ____
2.5-3.5
when warfarin (Coumadin) is utilized to Rx/prevent DVT/PE, the pt must keep INR therapeutic levels in the acceptable range of ____ to ____.
2.0-3.0
what do coagulation tests measure?
blood’s ability to clot as well as the length of time it takes
what do coagulation factor assays assess?
the fxn of coagulation factors
when are coagulation tests and assays used?
for pre-op testing, to assess unexplained bleeding, and to monitor anticoagulation therapies
what is PT time (prothrombin time)?
measurement used to determine the efficacy of the anticoagulant warfarin (Coumadin)
what is aPTT (activated partial thromboplastin time)?
used to monitor pt response to unfractionated heparin (no standardization)
there is no standardization for what coagulation test or assay?
aPTT
what is INR (international normalized ratio)?
calculates the pt prothrombin divided by the control prothrombin used to monitor pt therapeutic level of warfarin (Coumadin)
allows for comparable monitoring bw labs of warfarin and other vit k antagonists
what is the normal range for PT time?
11-12.5
what is the therapeutic range for PT time?
1/5-2x the control value
about 16-25
what is the normal range for aPTT?
30-40
what is the therapeutic range for aPTT?
1.5-2.5x the control value
about 45 to 100
what is the normal range for INR?
0.8-1.1
what is the therapeutic range for INR for DVT prophylaxis?
1.5-2.0x the control value
about 1 to 2
what is the therapeutic range for INR for hx of TIA or CVA and aortic valve replacement?
2.5-3.5x the control value
about 2 to 4
what is the therapeutic range for INR for PE?
2.5-3.5x the control value
about 2 to 4
what is the therapeutic range for INR for DVT, a fib, mitral/aortic valve replacement, orthopedic surgery?
2-3x the control value
about 2 to 3
when can someone on warfarin (Coumadin) be discharged home?
when the therapeutic range is met
what is a possible critical value for warfarin(coumadin)?
5.5
t/f: ranges for coagulation tests and assays are pt specific and dependent on pts acute condition, prescribed meds, and past medical hx
true
range for coagulation tests are dependent on what 3 factors?
the pt’s acute condition
prescribed meds
past medical hx
PTs should observe for what signs in a pt on anticoagulants?
increased bruising and bleeding
what are the clinical implications of warfarin (coumadin)?
fall prevention screening and interventions as needed
prolonged pressure if site bleeds
examine skin for bruising, patechilae, or blood in urine
changes in Neuro condition due to increased risk of intracranial bleeding
the anticoagulant effects of warfarin (Coumadin) can be reversed by what?
vit k
if a pt’s INR reaches > ___ clotting time, there is an increased risk for bleeding (internal, intracranial)
4.5
t/f: vit k may be given with warfarin (Coumadin) to lower an INR of greater than 5
true
pts taking warfarin (Coumadin) are advised to monitor what?
their dietary intake and limit food high in vit k
what foods are high in vit k?
leafy greens like spinach, broccoli, kale, brussel sprouts, cabbage, asparagus, and avocado
what 3 drinks should be avoided with warfarin (Coumadin)?
green tea
cranberry juice
alcohol
what do direct thrombin inhibitors do?
they bind directly to thrombin and inhibit its ability to convert fibrinogen to fibrin
what kind of anticoagulant is Lepirudin (Refludan)?
direct thrombin inhibitors
what kind of anticoagulant is Dabigatran (Pradaxa)?
direct thrombin inhibitors
how is Dabigatran (Pradaxa) administered?
can be given orally for stroke and systemic embolism prevention in pts w/AFib or DVT
how are direct thromin inhibitors administered?
IV or SQ
t/f: direct thrombin inhibitors are more effective and have less side effects with less drug interactions
true
what do factor Xa meds do?
directly inhibit factor Xa in clotting cascade
what are the factor Xa inhibitors?
Fondaparinux (Arixtra)
Apixaban (Eliquis)
Rivaroxaban (Xarelto)
how is Fondaparin (Arixtra) administered?
SQ following hip fx, Ortho surgery, and other surgery for DVT prevention
what are two of the biggest factor Xa meds given?
Apixaban (Eliquis) and Rivaroxaban (Xarelto)
what factor Xa meds are given orally for thromboembolic disease prevention, esp pts w/a fib?
Rivaroxaban (Xarelto)
what is another name for Rivaroxaban (Xarelto)?
NOACs or DOACs (new or direct oral anticoagulants)
how do antiplatelet meds work?
preventing excessive clotting caused by increased platelet activity to prevent arterial clots from forming
when are antiplatelet meds given?
with coronary artery occlusions, cerebral/carotid artery disease, or after cerebral infarct
what are the antiplatelet meds?
Aspirin
ADP receptor blockers
Glycoprotein 2b-3a receptor blockers
how does Aspirin work?
decreased platelet aggregation by inhibiting synthesis of PGs and thromboxane
what is an effective dose of Aspirin for antiplatelet effects?
75-325 mg taken orally
t/f: the antithrombotic effects of Aspirin are achieved bc it inhibits platelet fxn irreversibly
true
t/f: once the Aspirin reaches the platelet it inhibits it for its lifetime (7-8 days)
true
what are the indications for Aspirin as an antiplatelet med?
Rx and prevention of acute MI (men>women)
prevention of ischemic CVA (women>men)
prevention of DVT in peripheral veins
following athrosclerotic plaque formation
how do ADP receptor blockers work as antiplatelet meds?
it inhibits adenosine diphosphate receptors on the platelet membrane
what does ADP normally do?
signals increased platelet activity
what are the ADP receptor blockers?
Clopidogrel (Plavix)
Prasugrel (Effient)
Ticlopidine (Ticlad)
t/f: Clopidogrel (Plavix) can be used with Aspirin for “dual anti-platelet” therapy after cardiac surgery or stenting when Aspirin alone isn’t enough
true
which ADP receptor blockers is used a lot with unstable angina or when awaiting surgery?
Prasugrel (Effient)
ADP receptor blockers are used to prevent thrombosis in what pts?
pts with unstable angin, acute coronary syndromes, a fib, and those at risk for MI, ischemic stroke
ADP receptor blockers can be given to prevent what?
acute infarct following cardiac procedures/interventions (angioplasty and stenting)
how do glycoprotein 2b-3a receptor blockers work?
by inhibiting the ability of fibrin to activate platelets
blocks glycoprotein receptors on the platelet membrane stimulated by fibrinogen
fibrinogen therefore can’t bind, decreasing platelet induced clotting
what meds are the most powerful inhibitors of platelet activity?
glycoprotein 2b-3a receptor blockers
what are the primary indications for glycoprotein 2b-3a receptor blockers?
to prevent thrombosis following balloon angioplasty and other percutaneous coronary interventions
how are glycoprotein 2b-3a receptor blockers administered?
IV b4, during, and after (short-term) to maintain coronary blood flow and decrease mortality following balloon angioplasty
what are theglycoprotein 2b-3a receptor blocker meds?
Abaximab (Reopro)
Eptifibatide (Integrilin)
Tirofiban (Aggrastat)
how do fibrinolytic meds work?
facilitating the breakdown and dissolution of clots that already formed by converting plasminogen to plasmin
how are fibrinolytics administered?
IV
t/f: fibrolytics affect ALL vasculature
true
why is there an increased risk for intracranial hemorrhage with fibrinolytics?
bc they effect ALL vasculature
when are fibrinolytics contraindicated?
when a pt has a hx of hemorrhagic stroke, intracranial neoplasms, and internal bleeding
what are the 4 indications for fibrinolytics?
1) Rx of acute MI
2) Rx of acute ischemic CVA
3) dissolving clots in peripheral arteries and large veins
4) dissolving acute, massive PEs if life threatening and causing cardiac compromise
how soon after onset of symptoms of MI should fibrinolytics be given to restore coronary bloodf low, prevent myocardial damage, and Dec morbidity and mortality associated with MI?
12 hours
t/f: there is up to 50% decrease in negative effects of an MI if fibrinolytic are administered in less than an hour after onset of symptoms
true
why are fibrinolytic given to treat acute ischemic CVA?
bc they restore blood flow and prevent further damage to the brain tissue
how soon after onset of symptoms should fibrinolytics be given to treat acute ischemic CVA?
3 hours
when fibrinolytics are given to dissolve clots in peripheral arteries, how are they administered?
via intravascular catheter directly to the site of the clot
what 2 fibrinolytics are no longer used in the US?
Streptokinase and Urokinase
what are the fibrinolytic drugs?
TPA
Alteplase (Activase)
Reteplase (Retavase)
Tenecteplase (TNKase)
which fibrinolytic is used a lot w/ischemic stroke to break up a clot?
Alteplase (Activase)
what is the primary fibrinolytic agents used more effectively for cerebral vessels than coronary?
Alteplase (Activase)
what are Reteplase (Retavase) and Tenecteplase (TNKase) derived from?
human TPA
how are Reteplase (Reavase) and Tenecteplase (TNKase) given?
via a more rapid infusion called a “bolus”
a single injection given 2x, 30 minutes apart
what is the benefit of Tenecteplase (TNKase)?
it’s more specific for activating plasminogen and less risk of converting an ischemic stroke to a hemorrhagic stroke
what is the primary, most serious problem with anticoagulants?
hemorrhage
what type of hemorrhage is especially at risk with anticoagulants?
intracranial hemorrhage
what are PT implications for anticoagulants?
bruising and bleeding
fall risk
caution with wound care, deep tissue massage, chest percussion, and manual techniques
t/f: there is a lower risk of bleeding with new anticoagulant eds like Xa inhibitors and direct thrombin inhibitors leading to less risk for hemorrhagic conversion
true
what are potential adverse effects of anticoagulants?
hemorrhage
HIT
GI bleeds
liver/kidney toxicity
hypotension
excessive bruising
itching, nausea, anaphylaxis (fibrinolytics)
blood dyscrasia (Ticlid)
what are the blood dyscrasia with Ticlid?
neutropenia, thrombocytopenia, and agranulocytosis
what is HIT?
heparin induced thrombocytopenia
50% drop in platelet count w/in 4-10 days post heparin
very serious if it occurs and should d/c heparin and use a different anticoagulant
what things should pts watch for on anticoagulants?
blood in urine/stool
bleeding gums
unexplained, severe nosebleeds
increased menstrual flow
GI distress esp with Aspirin
when pts are on fibrinolytics, what should PTs be aware of?
the time of administration b4 mobilizing
