Flashcards in Antiplatelet Drugs Deck (27)
What processes do antiplatelet drugs target?
1) primary hemostatic plug formation
4) release mechanisms
How is a platelet aggregation assay performed?
1) prepare PRP
2) activate platelets
3) measure light transmittance
light goes thru --> aggregation
no light thru --> no agg
What 3 things are released by light granules?
1) platelet factor 4
2) beta thromboglobulin
3) platelet derived growth factor (PDGF)
What 3 things are released by dark granules?
What products are formed during platelet activation and endothelial interaction?
Why is there a specific niche for antiplatelet agents that cannot be covered by heparin and oral anticoags?
antiplatelet drugs act in arterial circulation
What are antiplatelet drugs used for?
primary and secondary prevention of thrombotic cerebrovascular/cardiovasc diseases
Name the 4 classes of antiplatelet agents
1) Aspirin - decreased platelet agg
2) COX inhibitors
3) propionic acid derivatives (ibuprofen, naproxen)
4) ADP receptor inhibitors
What are the ADP receptor inhibitors?
True or false: all ADP receptor inhibitors are prodrugs and require transformation into active forms in the liver
TRUE (except for ticagrelor)
What is the primary function of antiplatelet drugs?
to decrease platelet aggregation in the arterial system
What drug is used for the management of intermittent claudication?
Every patient undergoing open heart surgery takes ________ because it is a coronary vasodilator
What are the GP2b/3a inhibitors?
What likely causes aspirin resistance?
How does Clopidogrel act?
blocks ADP receptor so ADP cannot bind to the platelet and recruit more platelets
If a patient is not responding to clopidogrel, what do you do?
What is involved in dual antiplatelet therapy?
aspirin/ADP receptor inhibitors or GP2b/3a inhibitors or dipyridamole
What is involved in triple antiplatelet therapy?
aspirin/ADP receptor inhjbitor/cilostazol
what are the top 2 clinical applications of antiplatelet drugs?
1) Cerebrovascular disease (transient ischemic attack, complete stroke)
2) Cardiovascular disease (acute MI, unstable angina)
(also CABG, peripheral vascular disease)
True or false: drug interactions are minimal with antiplatelet drugs
FALSE they are profound (urokinase, streptokinase and tPA)
What are the 2 pathways arachidonic acid is metabolized?
1) COX (into prostaglandins)
2) lipoxygenase (leukotrienes)
What is the main mechanism by which aspirin mediates its therapeutic effects?
inhibits thromboxane formation in platelets
What is an inhibitor of the lipoxygenase pathway?
zileuton (used to treat asthma)
What are 2 leutotriene antagonists?
1) montelkast (asthma/allergies)
2) zarirlukast (asthma)
What exsmye is responsible for the formation of arachidonic acid?