Anticoagulants Flashcards
How does hemostasis happen?
- plt aggregation
2. coagulation
what needs to happen to platelets before they aggregate and form plug?
platelet activation before aggregation
what receptors are used to form bridges?
GPII/III receptor
undergo activation, aka undergo a configurational change that allows them to bind with fibrinogen
now it (platelet plug) has to be reinforced, how does that happen?
plug is unstable and must be reinforced with fibrin if protection is to last
coagulation cascade
2 pathways converge at factor
Xa
warfarin’s mechanism of action
vitamin K antagonist
name misleading. it is antagonism of vitamin k activation
what clotting factors is vitamin k necessary for
clotting factors 2, 7, 9, 10
can we use warfarin in situation where anticoagulation is needed urgerntly
no bc it does not get rid of already active clotting
what lab value do we monitor with warfarin
inr
mechanism of action with heparin
block clotting factor action
activation of antithrombin which inactivates factor xa and thrombin
heparin is preferred drug in pregnancy bc
it cannot cross placenta
polar molecule
example of direct thrombin inhibitor and how it works
dabigatron
inhibits thrombin
thrombin inhibition prevents conversion of blank to blank
fibrinogen to fibrin
so overall effect is less fibrin meshwork to support platelet plug
side effect of all anticoagulants
bleeding
how do factor xa inhibitors work
selective inhibition of factor xa
inhibits production of thrombin
prevent conversion of prothrombin to thrombin which ultimately decreases ___ production
fibrin
end result of all anticoagulants is less what
fibrin
accomplished in different ways
mechanism of action for aspirin
irreversaible inhibition of cyclooxygenase which blocks syntheis of TXA
Cox inhibits cycloxygenase but how does that prevent platelet aggregation?
aspirin inhibits
COX is necessary for conversion of arichidonic acid to thrombaxane A2 (which plays role in platelet aggregation/activation)
irreversible inhibition
effects last for life of platelet
How does clopogrel differ in mechanism of action?
block P2Y ADP receptor
It works to prevent platelet aggregation…just using different method
