AntiCoag Flashcards
3 types of drugs effecting coagulation
Anticoagulants
Antiplatelet
Thrombolytic Therapy
prevents the formation of clots- VENOUS (DVT)
Anticoagulants
inhibits platelet aggregation (arterial - MI/Stroke)
Antiplatelet Agents
dissolves life threatening clots
Thrombolytic
5 types of anticoag drugs
- Heparin
- Low Molecular Weight Heparin
- Vitamin K antagonist
- Direct Thrombin Inhibitors
- Direct Factor Xa Inhibitors
heparin is the prototype for …
heparin unfractionated!
How do anticoagulants work? What do they do?
=PREVENT clot formation
—>Increase time it takes the body to form clots
FXN:
-Inhibit synthesis clotting factors (factor X and thrombin)
OR
-Inhibit the activity of clotting factors (Xa, thrombin)
Uses for anticoagulant?
- Prevention of venous thrombosis
- –> DVT, pulmonary embolism, atrial fibrillation can throw clots
Routes for anticoagulants? When would you use which route?
- IV/SubQ = if life threatening = Heparin, LMWH
- Oral= long term use
Heparin is not a ____ ______
blood thinner
3 ways heparin fxns?
- Inactivates several clotting factors (factor Xa)
- inhibits thrombin activity
- suppresses formation of fibrin.
how is heparin measured?
in units
Route and reason for heparin?
- IV immediate action: PE/Stroke/Renal Dialysis – intermittent or continuous
- SQ-up to 1 hour for effect, abdomen, no aspirate/massage
half life for heparin? hours to reach therapeutic level of heparin?
1/2 life = 90 minutes
therapeutic = 6 hours
Antidote for heparin overdose? how often do we use it and why?
protamine sulfate (onset 5 min)
-hardly ever used…. -short half life of heparin = can just stop the IV drip and will resolve on its own
2 lab tests when on heparin?
- aptt
2. Anti-factor Xa level
aPTT measure _____ factor pathway
intrinsic
INpatient = IV heparin = INtrinsic =bigger # b/c more sick
Normal vss therapeutic levels of aPTT
- Normal = 40 sec
- Therapeutic levels = 1.5-2X baseline : 60-80 sec
How often do we measure aPTT on IV heparin?
every 6 hours
therapeutic levels fo Anti- factor XA levels?
0.3-0.7 IU/mL
Side effects of heparin?
- bleeding
2. HIT
What is HIT? what we monitoring for?
(Heparin Induced Thrombocytopenia) - monitor platelets.
->4 days use, body creates antibodies again heparin platelet protein complexes resulting in platelet drop
-If <100,000 or platelets reduce by 50% then stop heparin.
-If______ or platelets reduce by _____ then stop heparin.
-If <100,000 or platelets reduce by 50% then stop heparin.
how do you know if your patient is bleeding?
-petechiae, blood from orifices, bruises, discolored urine, lumbar pain
who is NOT getting heparin and why?
do not give with epidural or spinal anesthesia
—-> risk of hematoma
prototype for
Low Molecular Weight Heparin
enoxaparin(Lovenox)
how does enoxaparin(Lovenox) fxn?
same mechanism of action as heparin, but SAFER, better bioavailability
- Inactivates several clotting factors (factor Xa)
- inhibits thrombin activity
- suppresses formation of fibrin.
Benefits of enoxaparin(Lovenox)
- No frequent blood tests
- Dosage based on weight
- Can be administered at home
- longer half life - 6x longer
What is drug of choice for DVT prevention?
enoxaparin(Lovenox)
Side effects of enoxaparin(Lovenox)?
same as heparin!
bleeding, HIT
Check ______ before admining enoxaparin(Lovenox)
platelets
antidote to enoxaparin(Lovenox)
protamine sulfate, same as heparin
enoxaparin(Lovenox)- do or don’t expel the bubble?
Admin in the ____ only
Don’t expel the bubble!
Abdomen only!
prototype for Vitamin K antagonist
Warfarin (Coumadin)
how does Warfarin (Coumadin) fxn?
Vitamin K antagonist
inhibiting hepatic synthesis of vitamin K dependent clotting factors VII, IX, IX, X, and prothrombin
antidote for Warfarin (Coumadin)?
Will see effects in ___ hours
Antidote: Vitamin K (↓ effects in 6 hours)
enoxaparin(Lovenox) is only administered
SubQ
i think this is true? lemme know if its not
route for Warfarin (Coumadin)? which one has a risk?
Vitamin K antagonist
oral, IV (risk of anaphylaxis), SubQ
uses for Warfarin (Coumadin)
Vitamin K antagonist
-Prevent DVT, PE, prevent clots in patients with Afib, prosthetic heart valves or who had TIA or recurrent MI
Warfarin (Coumadin) is highly ____ bound
protein
drug/food interactions with Warfarin ?
Vitamin K antagonist
- Inactive by CYP2CP pathway
- Foods high in vitamin K , green leafy veg
- –> eat consistent amount of high vitamin K foods
VKORC1 & CYP2C9 variants =Increased risk of bleeding with which drug?
Warfarin (Coumadin)
Can you take Warfarin (Coumadin) while pregnant?
nope
Side effects of Warfarin (Coumadin)?
Hemorrhage
2 labs tests for Warfarin (Coumadin)?
- PT
2. INR
What do PT and INR measure : _____________pathway
EXtrinsic pathway
warfarin = outpatient =exit hospital
Normal range and therapeutic range for PT? test for which drug?
- PT normal 12 sec, Therapeutic = 1-2X baseline (12-24)
- warfarin
therapeutic level for INR? Test for which drug?
- INR (Internationalized Ratio) 2.0-3.0 = therapeutic level
- warfarin
which is more consistent to test platelets for Warfarin- INR or PT?
INR
half life of Warfarin (Coumadin)
Half life: 1.5-2 days
Teachings for Warfarin (Coumadin)
-Take same time every day
-Balance Vit K foods
-Watch s/s bleeding
—>labs
Soft toothbrush
-No straight edge razor
-Pain control drugs? Route?- best choice is tylenol! not aspirin/ibuprofen
-Venipuncture/ procedures- hold pressure longer, stop coumadin 1 week prior to surgery
-Medical Alert Bracelet
-Garlic? Gingko? - increase risk of bleeding
stop Warfarin (Coumadin) __ ___ prior to surgery
1 week
Don’t take the 2 supplements ___ or ____ with warfarin
garlic and gingko bilboa
–> increase risk of bleeding
Best choice for OTC pain control on Warfarin (Coumadin) is _____
tylenol!
-don’t take ASA or Ibuprofen
Prototype for Direct Thrombin Inhibitors
Prototype: dabigatran (Pradaxa)
How does Prototype: dabigatran (Pradaxa) fxn?
What locations of thrombin does it act on?
direct, REVERSIBLE inhibitor of thrombin that is free in blood and bound to clots
Route for dabigatran (Pradaxa)
Direct Thrombin Inhibitors
IV, SQ, oral
uses for dabigatran (Pradaxa)
Afib; hip/knee replacement (Canada)
side effects of dabigatran (Pradaxa)
bleeding, GI
Benefits of dabigatran (Pradaxa)
Direct Thrombin Inhibitors
- no lab monitoring
- lower risk of bleeding
- few drug-drug/ drug-food interactions
- rapid onset
- Set dose
stop taking dabigatran (Pradaxa) before ______
surgery
antidote for dabigatran (Pradaxa) ?
idarucizumab (Praxbind)
prototype for Direct Factor Xa Inhibitors?
Rivaroxaban (Xarelto)
apixaban (Eliquis)
how do Rivaroxaban (Xarelto) and apixaban (Eliquis) fxn?
binds with factor Xa and inhibits thrombin
route for Rivaroxaban (Xarelto) and apixaban (Eliquis)
oral only!
Direct Factor Xa Inhibitors
benefits of Rivaroxaban (Xarelto)and apixaban (Eliquis)
Direct Factor Xa Inhibitors
- Does not require anticoagulant monitoring
- Rapid onset
- Fixed dose
- Lower bleeding risk
- Few drug interactions (CYP3A4)
drug interaction with Rivaroxaban (Xarelto) and apixaban (Eliquis)
(CYP3A4)
Uses for Rivaroxaban (Xarelto) and apixaban (Eliquis) ?
Post hip/knee replacement, Afib, tx of DVT/PE
Side effects of Rivaroxaban (Xarelto) and apixaban (Eliquis)
Bleeding; spinal/epidural hematoma
Rivaroxaban (Xarelto) and apixaban (Eliquis) contraindicated in
liver disease and pregnancy
antidote forr Rivaroxaban (Xarelto) and apixaban (Eliquis)
andexanet alfa (AndexXa)
If on IV heparin and then need to switch to oral agent Rivaroxaban or apixaban (Direct Factor Xa Inhibitors)
- Stop heparin and immediately start oral does.
- May see doubled up doses for a couple of days, then once a day dosing.
If on IV heparin and need to switch to oral agent Warfarin…..
- Typically, 2-3 days simultaneous administration
- Takes a couple of days for warfarin to take effect
- No effect on clotting factors already in circulation
- Increased risk of bleeding
- Monitor both PTT and PT/INR
