6: Arterial thrombosis and anti-platelet drugs Flashcards
What blood components are involved in arterial thrombosis?
Platelets
What are three forms of arterial thrombosis?
MI
Stroke
Peripheral vascular disease e.g intermittent claud
What disease process often co-exists with arterial thrombosis?
Atherosclerosis
formation of fatty plaques in the lining of blood vessels which can rupture, initiating thrombosis and embolism
Atherosclerotic plaques are rich in ___.
cholesterol
Why is blood pressure an important risk factor for arterial thrombosis?
Increased pressure = Increased likelihood of plaque rupture
Which blood components bind to ruptured plaques in arterial thrombosis?
Platelets
What are four important cardiovascular risk factors for arterial thrombosis?
HTN
SMOKING
HIGH CHOLESTEROL
DIABETES
Which cells produce platelets?
Megakaryocytes
What chemicals are released from platelets to increase aggregation?
Thromboxane A2 (target of aspirin)
ADP (target of clopidogrel and prasugrel)
Ca2+
What aspects related to the vessel wall cause thrombosis in
a) arteries
b) veins?
a) Atheromas
b) Valves
What binds to platelets after they aggregate at the site of injury?
Platelet granules (ADP, thromboxane A2)
Von Willebrand’s factor
Clotting factors
How does aspirin inhibit primary haemostasis?
Cyclo-oxygenase (COX) inhibitor
COX converts arachidonic acid to prostaglandins (NSAID part)
Prostaglandins are converted to thromboxane A2
so aspirin inhibits inflammation AND primary haemostasis
What are some side effects of aspirin?
Bleeding
Peptic ulceration
Bronchospasm (re: aspirin asthma)
Why is aspirin avoided in patients with asthma?
Bronchospasm
Which antiplatelet drugs are more potent than aspirin?
How do they work?
Clopidogrel
Ticagrelor
Prasugrel
Target ADP, which facilitates platelet aggregation
