Anticoagulants Flashcards
What is the mechanism of heparin?
binds to antithrombin III and acts as a cofactor to increase antithrombin III activity.
lowers the activity of thrombin and factor Xa
Do you use APTT to monitor heparin?
YES
Dose heparin cause HIT? If HIT, what drugs can you use?
You can use direct thrombin inhibitors for HIT
Rivaroxaban inhibits what?
factor Xa
Hirudin, lepirudin, bivalirudin, argatroban inhibit what?
inhibit activity of free and clot associated thrombin
Can protamine reverse LMWH, or fondaparinux?
for LMWH partially
Will not reverse fondaparinux and direct Xa inhibitor activity
LMWH (-parin) need APTT to monitor?
No it does not
What is the mechanism of warfarin? Monitor by —?
Interferes with γ-carboxylation of vitamin K– dependent clotting factors II, VII, IX, and X, and proteins C and S.
Monitored by PT/INR (extrinsic pathway)
Why warfarin causes skin necrosis? What can prevent?
Low protein C
Activate 5 and 8
What drugs increase action of warfarin when combined:
P450 inhibitors:
Cephalosporins
Cimetidine
Macrolide antibiotics
Ketoconazole
Fluconazole
Metronidazole
Amiodarone
Sulfa drugs - displace free warfarin
Which can use in pregnancy? Heparin or warfarin? Why?
Heparin can be used in pregnancy. Warfarin no because it crosses the BBB
What drugs inhibit GPIIb/IIIa? What disorder do they mimic?
Monoclonal antibody: Abciximab
Fibrinogen analog: Eptifibatide and Tirofiban
Glanzmann’s thrombasthenia
What is the antidote for tPA? Heparin? Warfarin?
Warfarin antidote is Vitamin K (slow)
Immediate transfusion of fresh or frozen plasma
Aspirin inhibits what enzyme? By what–?
Irreversibly inhibit cyclooxygenase-1 (cox -1) enzyme
What is the antidote for thrombolytics?
aminocaproic acid and tranexamic acid
