Anticoagulation Flashcards
Define embolus
a clot or piece of clot that travels to another location
Where does warfarin work in the clotting cascade
inhibits factors 2,7,9,10
Where does UFH and LMWH work in the clotting cascade
inhibits Xa and Thrombin or 2a
What is UFH activity with Xa and 2a
has equally activity
What is LMWH activity with Xa and 2a
Has more Xa activity than 2a
Where do DTIs work in the clotting cascade
inhibit thrombin or 2a
List direct Xa inhibitors (3)
Rivaroxaban
Edoxaban
Apixaban
List indirect Xa inhibitor
Fondaparinux
List DTIs (3)
Argatroban
Bivalrudin
Dabigatran
Which DTIs and PO and which IV
PO -Dabigatran IV -Argatroban -Bivalrudin
Warfarin MOA
vitamin K antagonist. Vit K is required for activation of clotting factors 2,7,9,10 without vit K the liver produces the clotting factors but they have reduced coagulant acivity
Antithrombin does what?
inactivates thrombin and other proteases like factor Xa involved in blood clotting
MOA of UFH, LMWH, fondaparinux
bind to antithrombin causing a conformational change which increases AT activity 1000-fold
DTI MOA
bind to thrombin directly decreasing the amount of fibrin available for lcot formation
important point about IV DTIs
they do not cross-react with heparin-induced thrombocytopenia (HIT) antibodies
UFH antidote
protamine
LMWH dose for ppx of VTE
30 mg Q12 or 40mg Q24
LMWH dose for ppx of VTE with CrCl <30
30mg Q24
LMWH dose for treatment of VTE
1mg/kg Q12
LMWH dose for treatment of VTE with CrCL <30
1mg/kg Q24
LMWH antidote
protamine
Define HIT
immune-mediated IgG drug reaction that has a high risk of venous and arterial thrombosis
antidote for apixaban and rivaroxaban
andexanet alfa
Conversion between warfarin and DOAC
stop warfarin and convert to: Rivaroxaban when INR < 3 Edoxaban when INR <2.5 Apixaban when INR < 2 Dabigatran when INR <2 "read"
Antidote for dabigatran
idarucizumab
Goal INR for most indications
-DVT, Afib
2-3
Goal INR for mechanical mitral valve or 2 mechanical heart valves
2.5-3.5
Which foods does warfarin have increased bleeding with?
5 G's Ginger Ginkgo Ginseng Glucosamine
St. John’s Wort and Warfarin
decrease effectiveness of warfarin
High INR is bleeding or clotting?
bleeding
For pt with cancer and VTE which treatment is preferred
LMWH
CHA2DS2VASc
CHF HTN Age >75 DM Stroke Vascular Disease Age 65-74 Sex-Female
Prevention and treatment of VTE in pregnancy
LMWH
