Anticoagulants Flashcards
What is the primary function of vitamin K?
Blood clotting
What is the drug class of warfarin (Coumadin)?
Vitamin K antagonist
Describe the MOA of warfarin (Coumadin)
Inhibits vitamin K synthesis
What is a normal INR?
1
What is a therapeutic INR?
2 - 3.5
What labs / monitoring are associated with warfarin (Coumadin)?
PT/INR
Anticoagulants help prevent ______ strokes
Ischemic
What is the primary side effect of warfarin (Coumadin)?
Ecchymosis
What are the adverse effects of warfarin (Coumadin)? (2)
- Bleeding
- Skin necrosis
Why are there so many drug interactions with warfarin (Coumadin)?
It is highly protein bound
What is the route of warfarin (Coumadin)?
PO
The onset of warfarin (Coumadin) is about ______
48 hours
Anticoagulation effects start ______ after administration of warfarin (Coumadin)
24 hours
When is warfarin (Coumadin) usually given?
In the evening
Why is warfarin (Coumadin) administration timing (in the evening) so important?
Allows for changes in dosage after obtaining lab results (decreases drug interactions)
Describe the most significant concern associated with warfarin toxicity
Change in mental status - indication of intercranial bleeding
What are the 2 antidotes / reversal agents for warfarin (Coumadin) toxicity?
- Fresh frozen plasma
- Vitamin K
Describe the reversal of warfarin (Coumadin) toxicity using vitamin K
10 mg IV –> reversal in 6 hours
What is bridge therapy?
Use of heparin / LMWH (short-acting anticoagulants) when warfarin therapy is interrupted
What is the purpose of bridge therapy?
Minimize the risk of blood clots while the patient is not fully anti-coagulated
What is the effect of vitamin K use for reversal of warfarin toxicity?
Warfarin resistance for up to 7 days
What is the primary nursing consideration associated with warfarin (Coumadin)?
Slow onset - use bridge therapy
What are the 2 possible types of bridge therapy that can be used for warfarin (Coumadin)?
- IV heparin
- LMWH
Why are anticoagulants used for non-valvular atrial fibrillation / atrial flutter?
Blood pooling - risk of clotting / stroke
What are the 2 types of direct oral anticoagulants?
- dabigatran (Pradaxa)
- rivaroxaban (Xarelto)
Describe the primary nursing consideration associated with direct oral anticoagulants
Excreted by the kidneys - dose adjustments made based on renal function