Anticoagulants, Thrombolytics, Antiplatelet Therapies Flashcards
What are the 3 phases of coagulation
- Initiation
- Amplification
- Propagation
Anticoagulants
- Heparin
- Direct thrombin inhibitors
- Direct factor Xa inhibitors
- Warfarin
- DOAC
Antiplatelet
- Aspirin
- ADP inhibitors (Clopidogrel)
- Glycoprotein IIb/IIIa inhibitors
Which factors does Warfarin affect?
“1972”
2, 7, 9, 10
Which components does heparin affect?
2, 10
When should you put someone with a DVT or PE on aspirin?
- if they’ve had a DVT/PE
- No contraindication
In a patient who has had their first DVT episode, how long should they be anticoagulated for?
3 months
Heparin or Warfarin or LMWH
Parenteral anticoagulation is given….
BEFORE: dabigatran, edoxaban
NOT GIVEN: rivaroxaban, apixaban
OVERLAP: Warfarin
How is heparin dose calculated?
actual body weight
How is heparin monitored?
activated partial thromboplastin time (aPTT)
How is heparin reversed?
protamine sulfate IV
Thrombocytopenia
<100,000/uL platelet count
-more common with unfractionated heparin than LMWH
What is the principle difference in pharmacologic activity between LMWH and UFH?
relative inhibition of factor Xa and thrombin
LMWH: advantages over UFH
- more predictable dose response
- clearance doesn’t depend on dose
- less chance of thrombocytopenia
- less need for monitoring
- ->SAFER for extended administration
How is LMWH (Enoxaparin) dose determined?
weight based
If patient has pork allergy they can’t take heparin or LMWH. What should you put them on?
Fondaparinux
Monitoring: LMWH versus Warfarin
LMWH: aPTT
Warfarin: Prothrombin time (INR)
What is important to remember about starting Warfarin treatment?
when first initiated there is thrombosis due to protein C deficiency
Which Factor is affected first with Warfarin initiation?
Factor 7
order: 7, 9, 10, 2
Do DOACs have a reversal agent?
no
Which DOAC is a prodrug, targets thrombin, and needs to be adjusted if the patient has renal impairment?
Dabigatran
Which DOAC is most bioavailable ?
Rivaroxaban (xarelto)
Which DOACs work on factor Xa
Rivaroxaban
Apixaban
Edoxaban
Which DOAC is taken QD and must be taken with food?
Rivaroxaban (Xarelto)
Which DOAC has to be taken twice a day, but can be taken with or without food?
Apixaban (Eliquis)
How long is anticoag therapy recommended after DVT or PE?
at least 3 months
How long must heparin and warfarin be overlapped?
7 days
Does Rivaroxaban need to be used with heparin?
no
What is the goal INR for a mechanical heart valve?
2.5-3.5
What is the starting dose for Warfarin in a patient that can have daily INRs drawn?
5mg
How many times is the INR checked in the first 5 days of warfarin therapy?
5x
When should you get to INR goal for warfarin?
2-3 is only the goal on day 5. Before this you want it lower
What are dose adjustments based on for Warfarin?
total weekly dose
At what INR should you consider oral Vitamin K?
INR above 10
When can LMWH be discontinued?
After 5 days and 24 hours of INR in correct range
When should Warfarin be discontinued before a surgery?
4-5 days prior to surgery
Which two DOACs can you start at INR <2 when switching from Warfarin?
Dabigatran
Apixaban
Thrombolytics: MOA
convert plasminogen to plasmin
Direct thrombin inhibitors
Ex. Bivalirudin**, Desirudin, Argatroban
MOA: binds to thrombin and inhibits its enzymatic action
indication: anticoagulation in patient with heparin-induced thrombocytopenia (HIT)**
