Antithrombotics Flashcards
(26 cards)
The exposure of circulating blood elements to thrombogenic material, activation and aggregation of platelets, and triggering of the coagulation cascade are all elements to the formation of what?
A clot
After platelets adhere to the site of injury, how do they trigger aggregation?
Release reaction (secretion of platelet products)
Do collagen, thrombin, ADP, serotonin, fibrinogen, growth factor, procoagulants, and TXA2 activate or inactivate platelet aggregation?
Activate
What receptors allow binding of the platelets to fibringoen molecules?
IIb/IIIa
Which 4 drugs inhibit IIb/IIIa receptors, so platelets can’t aggregate?
ASA, thienophyridines, GP IIb/IIIa antagonists, and dipyridamole
ASA irreversibly acetylates and inactivates COX, which reduces which pro-aggrevating factor?
TXA2
Thienopyridines inhibit activation of the platelets by blocking the activation by which molecule?
ADP
When activated by the liver, which enzyme does theinopyridines block?
P2Y12
What are the 3 thienopyridines that are used currently?
clopidogrel, ticlopidine, and prasugrel
….that ADP is “-gel”ly….
Which is the most potent antiplatelet agents because they reversibly inhibit the aggregation by inhibitng the binding of activated platelet GP IIb/IIIa recepotors to fibrinogen and vWF?
GP IIb/IIIa receptor antagonists
So say your pt has an ASA intolerance, which drug can u give which increases platelet cAMP levels, which decreases Ca++ levels?
Dipyridamole
This si the class of drugs that interfered with the coagulation cascade and impair secondary hemostasis (formation fo the fibrin clot).
Anticoagulant drugs
What molcule is the main target for inactivation for heparin?
inhibits thrombin activation by factor Xa
So given the strengths, put the following in order from strongest to weakest:
dipryidamole thienopyridines ASA GP IIa/IIa antagonists pedal pump
GP IIb/IIIa antagonists»_space; Thienopyridines > Aspirin > pedal-pump»_space;> dipyridamole
This form of heparin is a mixture of glycosainoglycans, that, when assocated with antithrombin in the circulation, reduces thrombin ability to generate fibrin from fibrinogen.
Unfractionated hepatin
This form of heparin is more predictable and has a longer 1/2 life, smaller than UFH, and when associated with antithrombin, preferntially inhibits Xa rather than thrombin.
Low Molecular Weight Heparin
This is the main complication of heparin therapy, where there can be direct heparin-induced platelet aggregation or immune-mediated problems.
Heparin-induced thrombocytopenia (HIT)
In HIT, if there is direct hepatin-induced platelet aggregation, do you need to stop therapy?
Nah. It’s not too bad.
What are the crazy complications of immune-mediated form of HIT?
life-threatening bleeding and thrombosis
Do u need to stop heparin therapy if the pt develops immune-mediated HIT?
YES. YOULL KILL THEM YOU DICK.
Long term use of UFH can cause what other medical condition?
Osteoporosis
Say u give too much heparin and the pt starts to bleed a shit ton. What drug can u give to combat this?
protamine sulfate
This is the period of time where u overlap heparin and warfarin when treating thrombosis.
Anticoagulant bridging
Under what condition do u do anticoagulant bridging?
only when immediate anticoagulation is necessary
