Pharm Thrombosis Flashcards
Anticoagulants used for? Examples
venous thrombosis (heparins, Vit K antagonist, direct thrombin inhibitors, direct Xa inhibitors)
Antiplatelet drugs used for? Examples
arterial thrombosis (Cox inhibitor, P2Y12 (ADP receptor) inhibitors, GPIIbIIIa (fibrinogen receptor) inhibitors, phosphodiesterase inhibitors)
Fibrinolytic drugs used for? Examples
acute thrombosis - both venous and arterial (plasminogen activators)
Heparin used for?
immediate-acting - used initially for anticoagulation (parenteral)
Warfarin used for?
long term therapy - slow-acting (oral)
Heparins MOA
bind to and activate antithrombin - heparin-AT comblex inactivates IIa, Xa, IXa, XIa, XIIa
Disadvantage to herparin and major effects
requires hospitalization - effects: bleeding, HIT, osteoporosis in long term use
Low-molecular weight heparins
less non-specific binding - longer half-life - lower risk of HIT - mostly inhibits Xa but less effective against thrombin
Which anticoagulant is best for pregnancy?
low molecular weight heparin - enoxaparin
What is given for HIT?
fondaparinux
How is warfarin-induced thrombosis avoided?
always started while on heparin
Adverse effects of warfarin
teratogen and bleeding
Why is dosing of warfarin difficult?
competes with vit K which is influenced by diet, diarrhea, laxatives, antibiotics, fat absorption ALSO 99% is bound to albumin (interference by other drugs) - NARROW THERAPEUTIC WINDOW
How is warfarin monitored?
using international normalized ratio (INR) - used to standardized (PT/normal PT)^ISI
ISI determined by manufacturer
How is warfarin therapy reversed?
- stop giving it
- give vit K
- give prothrombin factor concentrate
- give fresh frozen plasma
Dabigatran
oral, competitive inhibitor of thrombin, few drug interactions, safe over large range of doses, renal clearance, but NO reversal
What are the direct Xa inhibitors?
-xabans
Fibrinolytic drugs mechanism
activate plasminogen to plasmin
What are the fibrinolytic drugs?
-teplases
What are the fibrinolytic drugs based off of?
streptokinase - bacterial protein which was non thrombus selective (-teplases more clot-specific with teneceteplase being most specific)
Aspirin mechanism
irreversibly binds to COX-1 - low dose is a more effective antiplatelet agent
P2Y12 blockers
block ADP receptor. -grels
GPIIb/IIIa inhibitors
fibrinogen receptor inhibitor. have -fib in name and also ABCiximab
