Antiplatelets Flashcards
What is the difference between an arterial and venous thrombus?
Arterial= high platelets, Low cell count, white and usually form at the site of atherosclerosis following a rupture (due to changes in the blood composition)
Venous thrombosis= Low platelet (therefore you would use anticoagulants), would be high cell and red.
What drug is normally given first line in an ARTERIAL thrombosis?
So remember that arterial is usually high platelet therefore you would give anti platelet medication…
Normally give aspirin: reduction of thromboxane A2- a potent platelet aggregation agent synthesis by COX-1 inhibition
It inhibits platelet aggregation irreversibly.
Would you give aspirin in a high dose or low dose for a patient that has experienced an MI?
Would give in a low dose, at high dose it inhibits COX-1 which is also involved in the synthesis of prostacyclin, and therefore could cause vasoconstriction, which isn’t what you would want to happen.
What is adenosine used for?
Adenosine is used to restore the sinus sprythm in surgery etc, used for re-entrant arrhythmias.
What is dipyridamole?
So dipyridamole is a phosphodiesterase inhibitor and inhibits platelet aggregation
When would you use clopidogrel?
In a stroke or ischsemic a P2Y12 receptor antagonist
How does abciximab work?
It should only be used once, as an adjunct to heparin and aspirin, it irreversibly binds to GP2b and 3a receptors (on platelets) and prevents the binding of fibrinogen and vWF and decreases platelet aggregation.
If you need to complete surgery, what is it important to check that the patient is on and why?
If they are on aspirin, as this would increase risk of breathing, need to check at least 7-10 days before as this is irreversible!!
If someone has suffered a stroke, what is it important to check before hand and how is this done?
Important to check if it was haemorrhagic or not, done by a CT, will show up white straight away if haemorrhagic and you shouldn’t give aspirin or warfarin in these cases, as will make it worse.
