Flashcards in Anticoagulants Deck (14):
what is an INR range when you can switch from heparin + warfarin to warfarin alone?
INR: 2-3 therapeutic range
Compare contrast warfarin/heparin:
Onset of action
Antidote for OD
Measurement of action
Heparin: IV or subcu admin; Warfarin: oral admin
Heparin: short half life; Warfarin: long half life
Heparin: rapid onset of action; Warfarin: slow onset
Heparin: protamine sulfate; Warfarin: fresh frozen plasma, Vit K
Heparin: monitor PTT; Warfarin: monitor PT
Heparin: doesn't cross placenta; Warfarin: teratogenic
Which 2 things does heparin decrease in its MOA?
decreases thrombin and factor 10a
What is a serious complication of heparin at times?
HIT: heparin induced thrombocytopenia
heparin attaches to platelet factor 4. IgG antibody against that.
Get clotting everywhere and consumptive thrombocytopenia
How should you manage the thrombosis during HIT?
use direct thrombin inhibitor, like bivalirudin or argatroban
What is enoxaparin and dalteparin?
along w/ fondaparinux
act more on decreasing Factor 10a
longer half life
don't need to monitor, can give subcu
if you needed to monitor--take a lot at 10a activity
What are the direct thrombin inhibitors?
bivalirudin, lepirudin, desirudin: from hirudin taken from leeches. Inhibits thrombin directly.
Argatroban, dabigatran--other direct thrombin inhibitors.
What is the exact MOA of warfarin?
inhibits epoxide reductase that gamma carboxylates Vit K depending clotting factors
What is one crazy side effect of warfarin?
skin/tissue necrosis due to small vessel micro thromboses
higher rate of this seen in Protein C/S deficiency
What are the structures of heparin and warfarin?
heparin: large, anionic, acidic polymer
warfarin: small, amphipathic molecule
What are the direct factor 10a inhibitors?
good for DVT, PE, afib
don't require a bunch of monitoring
What is the MOA of the thrombolytics?
convert plasminogen-->plasmin. This cleaves thrombin and breaks down fibrin clots.
What happens to labs after admin of thrombolytics?
increase in PT, PTT. NO change in platelet count