Anti Platelet Agents (Stable Angina CAD) Flashcards
What is the MOA of Aspirin
Irreversible
Inhibits TxA2
What are the indications for ASA daily Tx? Why?
Men >65
Women > 55
For thromboprotection
How long does it take for ASA to metabolize and where?
Half life 2-3 hrs initially then 15-30 once hepatic metabolism is saturated
What are the SE of ASA?
GI bleed- age + dose influence
H2RA or PPI for gastroprotection
Tinnitus (salicyclate toxicity, bruising or bleeding)
Extra info for ASA-
How to take during ACS,
what decreases bioavailability and how is it metabolized?
Chew and swallow during ACS- inc. bioavailability
Enteric coating decreases bioavail
Erythrocytes metabolize ASA into salicylate in GI
Considerations of ASA
if pt stops ASA- body makes new platelets–(10% per day) and they live for 7 days
ASA has a lot of salt to consider BP!
Clopidogrel MOA
Irreversible
Inhibits ADP mediated platelet activation by GP IIB/IIIA via shear stress
Clopidogrel Indications
PAD, vascular Dz– better than ASA
used instead of ASA if allergic or intolerant
Metabolism of Clopidogrel
Bioactivated by CYP2C19
Active antiplatelet metabolite with half life of 8 hours
SE of clopidogrel
bleeding- especially if older, Low body weight, on NSAIDS or on Warfarin
DI of Clopidogrel
Ompreazole and PPI are major DI
use an H2 blocker or space out drugs 12 hours apart
Considerations for Clopidogrel
stop 7 days before major surgery
Prasugrel MOA
Irreversible
Inhibits ADP mediated platelet activation by CYP3A4/3A5
Prasugrel Indications
protections of cardiac BMS or DES for 12 mo
12 mo in non cardiac vessel stents
Prasugrel Metabolism
slightly more effective than clopidogrel and avoid CYP2C19 interactions with PPIs
Contraindications of Prasugrel
hx of hemorrhagic events
hx of stroke or TIA
SE Prasugrel
Bleeding if body wt 75 yo
Extra/DI for Prasugrel
consider pharmacodynamics and bleeding if pt is on ASA, NSAIDS, or warfarin
Considerations for Prasugrel
do NOT give if pt is
Ticgrelor MOA
Reversible
Inhibits ADP mediated platelet activation
*dose dependent!
Ticgrelor Indications
protections of cardic BMS or DES for 12 mo
12 mo in non cardiac vessel stents
Ticgrelor metabolism
CYP3A4 to active metabolite
half life 7 hours (parent.) & 9 hrs (metabolite)
Contraindications of Ticgrelor
Active liver dz- bc its >99% protein bound
SE of Ticgrelor
Bleeding
hepatic dx greatly increases this risk