Antiplatelets

Question 1

Antiplatelets

Answer 1

Primarily used against arterial clots
COX inhibitors, P2Y inhibitors only block one pathway
GP IIb and IIIa inhibitors block the final step of plt aggregation and activation

Question 2

Aspirin

Answer 2

Ischemic stroke prevention, TIAs. Angina stable and unstable. coronary stents, acute myocardial infarctions
IRREVERSIBLE inhibits COX to reduce PLT activation. 81 mg = max plt effect

Contra: use in kids and teens with viral infections (Reye’s syndrome)
ADR: GI bleeds

Question 3

Clopidogrel

Answer 3

Plavix
STEMI and NSTEMI, stroke, peripheral atherosclerosis
BOX: diminished effects in CYP2C19 in poor metabolizers
IRREVERSIBLY blocks P2Y12

CONTRA: active bleeding. (ulcers)
ADR: Bleeding.

MUST BE metabolized by 2C19 into active drug. PPI will inhibit 2C19, reducing the effect on PLTs, but not clinically significant.

Question 4

Prasugrel

Answer 4

Acute coronary syndrome
Higher risk for bleeding and cancer that clopidogrel
Irreversibly blocks P2Y12
CONTRA: active bleeding, prior TIA or stroke
ADR: Bleeding

Question 5

Prasugrel BOX warnings

Answer 5

Significant bleeding, sometimes fatal
not for senior citizens, low weight pts, meds that increase bleeding risk, hypotensive pts
not for pts with urgent CABG surgery (7 days)
If already on it, bleeding needs to be managed while meds are continued

Question 6

Ticagrelor

Answer 6

Acute coronary, prevention of ischemic cardio events in CAD, or ischemic strokes/high risk TIA
BOX: avoid in pts on Aspirin higher than 100mg. avoid in pts with pathological bleeding
REVERSIBLE p2y inhibition
CONTRA: same as box
ADR: dyspnea 20%

Question 7

Cangrelor

Answer 7

Pts who remain high risk of thromboses and cant tolerate oral p2y OR used in cardiogenic shock
reversible p2y
CONTRA: active bleed
ADR: bleeding

Question 8

Vorapaxor

Answer 8

History of MI or peripheral artery disease. reduce thromboses
PAR-1 inhibitor to inhibit plt aggregation
CONTRA: hx of stroke
ADR: bleeding

Question 9

G2B/3A Inhibitors

Answer 9

ACS to prevent ischemic events in those undergoing PCI. ONLY at Primary PCI facilities. MOST EFFECTIVE antiplatelet drugs
Reversible blockade of GP2b/3a receptors, inhibits final aggregation step
CONTRA: active abnormal bleed, hx of stroke, severe HT, recent major surgery

Question 10

Dipyridamole

Answer 10

Prevent recurrent stroke or TIA. Used in combination with aspirin. Better together BUT scandal data. Not used often. Doesn’t use enough aspirin to prevent MI
inhibits uptake of adenosine to prevent plt aggregation
CONTRA: same as aspirin
ADR: bleeding and GI issues. avoid use in severe liver/renal impairment