Arterial thrombosis and anti platelet drugs Flashcards
arterial thrombosis treatment
aspirin and other anti platelet drugs
modify risk factors for atherosclerosis
what is atherosclerosis
damage to the endothelial
recruitment of foamy macrophages rich in cholesterol
forms plaques rich in cholesterol
stable atherosclerotic plaques
hyalinised and calcified
stable plaques - stable angina, intermittent claudication
unstable atherosclerotic plaques
plaques rupture, platelets are recruited and cause acute thrombosis
sudden onset of symptoms
unstable angina or MI
stroke
what can unstable atherosclerotic plaques lead to
acute organ iscaeqhmia and infarction
platelets in arterial thrombosis
platelet adheres to ruptured plaque - exposed endothelial and release of VW factor
platelets become activated - release granules that activate coagulation and recruit other platelets to developing platelet plug
platelet aggregation via membrane glycoporteins
risk factors for arterial thrombosis
htn - damage to endothelium and platelet activation
smoking - endothelium, platelets
high cholesterol - accumulated in plaque
DM - endothelium, platelets, cholesterol
prevention of arterial thrombosis
stop smoking treat htn treat DM lower cholesterol anti platelet drugs
how to platelets bind to subendothelial collagen
via glycoprotein 1b and VWF
how does platelet aggregation occur
platelets attach to each other via GPIIbIIIa and fibrinogen
what is platelet activation
platelets later their shape to expose more phospholipid on the surface - provides greater SA for coag activation and fibrin production to stabilise the clot
process is augmented by release of granules that further stimulate platelet activation - more platelets
happens via receptors to ADP etc on platelet surface
aspirin
inhibits cyclo-oxygnease which is necessary to produce thromboxane A2 - a platelet agonist released from granules on activation
SE of aspirin
bleeding
blocks production of porstoglandings: GI bleeding, bronchospasm
clopidegrol, pradugrel
ADP receptor antagonists
dipyridamole
phosphodiesterase inhibitor - reduces production of cAMP which is a second messenger in platelet activation
