Antiplatelet Agents

Front 1

Indication for anti-platelet agents?

Back 1

arterial thrombosis

Front 2

Approaches to anti-platelet therapy? (4)

Back 2

1. inhib platelet adhesion
2. inhib platelet activation/secretion
3. inhib platelet aggregation
4. inhib procoagulant activity

Front 3

Ligand/receptor for platelet adhesion?

Back 3

vW factor/ glycoprotein Ib/IX

Front 4

Ligand/receptor for platelet aggregation?

Back 4

Fibrinogen/ GPIIb/IIIa

Front 5

Platelet activating substances? (4)

Back 5

1. Thromboxane
2.PAF

Front 6

Indication for anti-platelet agents?

Back 6

arterial thrombosis

Front 7

Approaches to anti-platelet therapy? (4)

Back 7

1. inhib platelet adhesion
2. inhib platelet activation/secretion
3. inhib platelet aggregation
4. inhib procoagulant activity

Front 8

Ligand/receptor for platelet adhesion?

Back 8

vW factor/ glycoprotein Ib/IX

Front 9

Ligand/receptor for platelet aggregation?

Back 9

Fibrinogen/ GPIIb/IIIa

Front 10

Platelet activating substances? (4)

Back 10

1. Thromboxane
2.PAF
3. ADP
4. Collagen

Front 11

What does prostacyclin (PGI2) do for cAMP and aggregation?

Back 11

increase cAMP, decrease aggregation

Front 12

What does Thromboxane (TXA2) do for cAMP and aggregation?

Back 12

decrease cAMP, increase aggregation

Front 13

Platelet phospholipid surface crucial for?

Back 13

coagulation cascade

Front 14

Name the two ADP receptor inhibitors

Back 14

Ticlopidine
Clopidigrel

Front 15

What do ADP -receptor blockers do?

Back 15

inhibit ADP-induced platelet aggregation

Front 16

What is ticlopidine a derivative of?

Back 16

Thienopyridine (prodrug)

Front 17

What does ticlopidine do?

Back 17

blocks ADP receptor, inhibiting platelet aggregation and degranulation

Front 18

When is ticlopidine used?

Back 18

unstable angina, TIAs, stroke, peripheral vascular disease. After placement of intracoronary stents

Front 19

What are ticlopidines side effects? how bad are they?

Back 19

nausea, diarrhea, hemmorhage, neutropenia - BAD

Front 20

What is clopidogrel a derivative of?

Back 20

Thienopyridine

Front 21

What does clopidogrel do?

Back 21

irreversibly blocks ADP receptors

Front 22

How long does it take for clopidogrel to take effect?

Back 22

4 -7 days (lasts 7-10)

Front 23

When is clopidogrel used?

Back 23

acute coronary syndrome; risk reduction in pts with recent CVA, MI or PAD

Front 24

What did the CAPRIE trial show?

Back 24

clopidogrel slightly better than aspirin in preventing MIs and strokes

Front 25

What did the CURE study show?

Back 25

aspirin + clopidogrel better than aspirin alone in preventing MI/stroke/CV death (20% risk reduction)

Front 26

What is a dangerous condition associated with both clopidogrel and ticlopidine?

Back 26

TTP - meds block ADAMTS13

Front 27

With patient on ticlopidine or clopidogrel, how do you check for TTP?

Back 27

check platelets weekly (1st month of treatment), educate on warning signs of TTP

Front 28

What would thrombin receptor inhibitors do?

Back 28

Block platelet activation and aggregation, some under development, none on market

Front 29

What does aspirin do? (4 steps)

Back 29

Irreversibly inhibits COX-1 which inhibits arachadonic acid generation which inhibits TXA2 secretion which inhibits platelet activation

Front 30

How long until aspirin takes effect? How long does it last?

Back 30

15-20 min, 7 days

Front 31

What is the long-term use dose of aspirin?

Back 31

81 mg

Front 32

Why use a low dose of aspirin?

Back 32

fewer GI side effects, less risk of bleeding, similar antiplatelet effects

Front 33

Who is on lifelong aspirin?

Back 33

Pts with ACS, CVA, or PCI

Front 34

What is the anti-platelet mechanism of PDE inhibitors?

Back 34

less PDE means less breakdown of cAMP which means less platelet function

Front 35

What are the PDE inhibitors? (3)

Back 35

Dipyridamole, Cilostazol, Aggrenox (aspirin + dipyridamole)

Front 36

How do GPIIb/IIIa inhibitors work?

Back 36

bind to activated receptor and directly block platelet aggregation, "final common pathway"

Front 37

What are the three GPIIb/IIIa inhibitors?

Back 37

1. Abciximab
2. Eptifibatide
3. Tirofiban

Front 38

What is abciximab?

Back 38

a chimeric antibody to the GPIIb/IIIa receptor

Front 39

How is abciximab given?

Back 39

IV and short term

Front 40

At what occupancy does abciximab completely inhibit ADP-induced platelet aggregation?

Back 40

80%

Front 41

What is eptifibatide?

Back 41

A cyclic heptapeptide from snake venom that selectively blocks GPIIb/IIIa receptors and prevents platelet aggregation

Front 42

When is eptifibatide used?

Back 42

prevention of thrombosis in PCTA (percutaneous angioplasty), MI, angina

Front 43

What is the t1/2 of eptifibatide and where is is cleared?

Back 43

2.5 h, the kidney

Front 44

What is tirofiban?

Back 44

snake venom GP IIb/IIIa receptor inhibitor.

Front 45

When is tirofiban used?

Back 45

PCTA, MI, unstable angina

Front 46

What did the PRISM-PLUS study find (wrt tirofiban)?

Back 46

adding tirofiban to heparin decrease risk of repeat MI/death by 35% in 7 days post MI

Front 47

How often does thrombocytopenia occur with GPIIb/IIIa inhibitors?

Back 47

0.5% of exposures, more with abciximab, more with repeat exposures

Front 48

How is the thrombocytopenia following GPIIb/IIIa inhibitors mediated?

Back 48

Through naturally occuring abs that don't require prior exposure (=weird)