Lec 11-12 Pharm anti-coagulants Flashcards
What is action of unfractionated heparin?
binds antithrombin [AT] –> makes it more active in its ability to inactivate thrombin [II], IX, X, XI, XII
mostly thrombin and X
How is unfractionated heparin administered?
parenterally [IV or subQ]
What is half life of heparin?
1 hours
Do you have to monitor unfractionated heparin? how?
monitor by PTT
What are complications of heparin?
- bleeding
- heparin induced thrombocytopenia –> thrombosis
- osteopenia + osteoporosis
- allergy
What is antidote to unfractionated heparin?
protamine sulfate
How does HIT happen?
get antibodies against heparin - platelet factor 4 complex
How can you test for HIT?
heparin-platelet factor 4 antibody
serotonin release assay
What is action of low molecular weight heparin [LMWH]?
inhibit factor X rather than thrombin [II]
Do you have to monitor LMW heparin? how?
nope!
What is half life of LMWH?
3-18 hrs = longer than unfractionated
Can you get HIT with LMWH?
yep but less likely
Can you use protamine to reverse the effects of LMWH?
nope
What is fondaparinux?
synthetic inhibitor of factor X
What is warfarin?
oral anti-coagulant –> inhibits epoxide reductase and thus creates vit K deficiency
What is 1/2 life of warfarin?
36-42 hours
How do you monitor warfarin?
PT/INR
What are 3 complications of warfarin?
- bleeding
- warfarin skin necrosis
- teratogen
What are the 2 direct thrombin inhibitors?
lepirudin
argatroban
What is lepirudin?
derived from leeches; binds directly to thrombin at catalytic site
direct thrombin inhibitor
Who should you give lepirudin?
pts with HIT
What drugs are safe for HIT?
- lepirudin
- argatroban
What is argatroban?
synthetic thrombin inhibitor
direct thrombin inhibitor
What is the use of new oral anticoagulants [NOACs]?
treatment of non-valvular Afib, deep venous thrombosis, pulmonary thrombosis
What is the mech of action dabagitran?
thrombin IIa inhibitor
What are the 3 factor Xa inhibitors?
edoxaban
apixaban
riveroxaban
Do the new oral anticoagulants require monitoring?
nope!
WHat is use of thrombolytic agents?
dissolve existing thrombi
- treat acute MI
- massive PE
- peripheral artery occlusion
What is action of thrombolytics?
convert plasminogen to plasmin
What are the 3 thrombolytics?
- streptokinase
- urokinase
- tPA
What are the 4 drugs that inhibit ADP receptor P2Y12 on platelets and thus prevent aggregation?
- ticlopidine
- clopidogrel
- prasugrel
- ticagrelor
What are the 3 drogs that block the a2b3 platelet receptor and thus preven fibrinogen binding platelets?
- abciximab
- eptifibitide
- tirofiban
What is the mech of action aspirin?
irreversible inhibitor of cyclooxygenase –> impaired TXA2 production and platelet aggregation
