Antiplatelets

Question 1

Indications for Aspirin

Answer 1

Atherothrombosis Venous thromboembolism
Colorectal cancer
Cognitive impairment
History of MI
Acute coronary syndromes
Stable or unstable angina
Stroke Transient ischemic attack
Peripheral artery disease

Question 2

Contraindications for Aspirin

Answer 2

True hypersensitivity
Active bleeding
Severe bleeding risk

Question 3

Side effects of Aspirin

Answer 3

Dyspepsia to erosive gastritis or peptic ulcers with bleeding and perforation
Used with NSAIDs increase GI complications 3-4 fold
Increases risk of stroke in men by factor of 1.7, not in women

Question 4

MOA of Aspirin

Answer 4

Blocks synthesis of thromboxane A2 by blocking COX-1 and 2

Question 5

MOA of Dipyridamole

Answer 5

PDEIII inhibitor that increases levels of cAMP in platelets by:

1. Blocking the reuptake of adenosine
2. Inhibiting PDE mediated cAMP degradation cAMP reduces Ca levels which inhibits the platelet activation

Question 6

Indications for Dipyridamole

Answer 6

Ischemic stoke or transient ischemic attack
Cardiac imaging - diagnostic IV agent for coronary artery disease (do not use if history of reactive airway disease)

Question 7

Side effects of Dipyridamole

Answer 7

GI complaints
Headache
Facial flushing
Dizziness and hypotension

Question 8

MOA of Clopidogrel

Answer 8

Prodrug that is an ADP receptor inhibitor that ultimately interferes with platelet activation. Metabolized hepatically by CYP2C19 where only 2-15% is active. (Black box warning, some people may be poor metabolizers)

Question 9

Indication for Clopidogrel

Answer 9

Used in combo with aspirin
Acute coronary syndrome
Stent thrombosis after PCI CAD, CVD, or PAD
Minor stroke/TIA

Question 10

MOA of Prasugrel

Answer 10

ADP inhibitor, more potent than clopidogrel and faster onset of action.
Higher concentration of active metabolite, less susceptible to genetic variation and drug interactions. “irreversible”

Question 11

Contraindications of Prasurgrel

Answer 11

Patients smaller than 60kg half dose recommended
Should not be used in patients with Hx of stroke/TIA
Not used in patients greater than 75 years old
Not used in revascularization/PCI
Not to be initiated until coronary anatomy is known and CAPG ruled out

Question 12

MOA of Ticagrelor

Answer 12

Reversible and non-competitively binds outside active site.
Faster onset and more potent platelet inhibition than clopidrogrel.
Starts as an active metabolite.

Question 13

Adverse effect of Ticagrelor

Answer 13

Dyspnea (15%) people get the sensation of dyspnea because of neuronal P2Y12 receptors in neuronal tissues that cause vagal stimulation

Question 14

MOA of Cangrelor

Answer 14

IV only
Also ADP receptor inhibitor
Higher bleeding rates than clopidogrel and can cause dyspnea similar to Ticagrelor

Question 15

MOA of Cilostazol

Answer 15

Phosphodiesterase inhibitor

Question 16

Indications for Cilostazol

Answer 16

Question 17

Contraindications of Cilostazol

Answer 17

Heart failure of any severity

Question 18

MOA of Vorapaxar

Answer 18

PAR-1 inhibitor (platelet thrombin receptor) Inhibits thrombin induced platelet aggregation

Question 19

Indications of Vorapaxar

Answer 19

Post MI patients at risk for secondary atherothrombotic events Initiate in stable patients 2 weeks after an MI on antiplatelet therapy

Question 20

Contraindication of Vorapaxar

Answer 20

History of stroke/TIA ICH or active bleeding Used in caution with low body wieght, old age

Question 21

MOA of GP IIb/IIIa inhibitors

Answer 21

Inhibit platelet aggregation

Question 22

GP IIb/IIIa contraindications

Answer 22

Active bleeding Severe hypertension CVA Major surgery of trauma Thrombocytopenia Bleeding diathesis/warfarin with elevated INR

Question 23

Major adverse effect of GP IIb/IIIa inhibitors

Answer 23

Thrombocytopenia

Question 24

Abciximab

Answer 24

Short half life, platelet bound for days, use in renal failure patients because not renally cleared

Question 25

Eptifibatide and tirofiban half life

Answer 25

Long (2 hours) half life, platelet bound short, renally cleared

Question 26

ADP receptor inhibitors

Answer 26

Question 27

ADP receptor inhibitors indications

Answer 27

Question 28

ADP receptor inhibitor adverse effects

Answer 28

Question 29

Glycoprotein IIb/IIIa inhibitors

Answer 29