Anticoagulants, Antiplatelets Flashcards
Warfarin (coumadin):
- MOA
- Vit. K factors
Inhibits posttranslational modification of the Vit.K dependent coag factors
-F2,7,9,10,C/S
What 2 genes have the greatest impact on Warfarin (coumadin)?
- VKORC1
- CYP2C9
What is the best test for monitoring Warfarin (coumadin)?
-Target range
TP test w/ INR modification
-2.0-3.0
What is Unfractionated Heparin made up of?
Heterogenous mixture of mucopolysacharides, ranging widely in size
What does Heparin bind to and what is the effect?
Antithrombin (AT)/Enhances ability to INACTIVATE:
- Thrombin/FactorXa (10a)
- F9a,F11a,F12a
What is the preferred test to monitor Heparin therapy?
aPTT (preferred)
-Anti-Xa assay may also be used
Heparin Reversal:
- NOT Urgent
- Urgent
- Discontinuing Heparin results in normalization of aPTT within 1 hour
- Urgent - Protamine Sulfate
MOA of Low Molecular Weight Heparin (LMWH).
Like UH, interacts with AT to inactivate:
-FXa and Thrombin
How do you monitor LMWH?
Anti-Factor Xa assay
-4 hours post injection
T/F: Protamine sulfite does not neutralize LMWH as effectively as UH.
True
What is a Direct Factor Xa (10a) inhibitor, that does not inactivate Thrombin?
-What are the new oral meds called
Fondaparinux (Arixtra)
- Apixaban
- Rivaroxaban
What is the active compound in Direct Thrombin Inhibitors?
-Derived from?
Hirudin (inhibit Thrombin w/o AT)
-Salivary glands of the Leech H. medicinalis
*Lepirudin, Desirudin, Agatroban, Bivalirudin
What is the primary use of Agatroban?
Prevention of thrombosis in pts w/ HIT
What is the MOA of Dabigatran?
Direct Thrombin Inhibitor
MOA of Aspirin (acetysalicylic acid).
Antiplatelet effects:
- Irreversible inhibition of plt COX-1
- Blocks action of TXA2*
*TXA2 causes platelet activation and local vasoconstriction
