Antithrombotics

Question 1

Primary hemostasis steps

Answer 1

Platelet shape change and activation
Platelet adhesion
Platelet aggregation

Question 2

Secondary hemostasis step

Answer 2

Activation of intrinsic/extrinsic coagulation cascades

Question 3

ADP activates platelets through a G_ protein coupled receptor

Answer 3

Gi

Question 4

Anti platelet drugs

Answer 4

Aspirin
Clopidogrel
Abciximab
Vorapaxar

Question 5

Thrombolytic drug

Answer 5

T-PA

Question 6

Vitamin K antagonist

Answer 6

Warfarin

Question 7

ADP receptor antagonist

Answer 7

Clopidogrel

Question 8

Clopidogrel MOA

Answer 8

Prodrug metabolized in liver
Blocks platelet aggregation by binding irreversibly to P2Y12 ADP receptors

Question 9

Clinical uses of clopidogrel

Answer 9

Reduce rate of stroke, MI, atherosclerosis
Similar but slightly.,more effective than aspirin

Question 10

Black box warning for clopidogrel

Answer 10

Therapeutic failure in patients with loss of CYP2C19*2 allele
(Need to be tested for allele before starting drug)

Question 11

Adverse effects of Clopidogrel

Answer 11

Bleeding
GI upset
Thrombotic thrombocytic purpura

Question 12

Drug interactions with Clopidogrel

Answer 12

NSAIDs
omeprazole

Question 13

Abciximab MOA

Answer 13

GPIIb/IIIa antagonist
Blocks platelet aggregation/fibrinogen binding

Question 14

Clinical use of abciximab

Answer 14

Most effective anti platelet drug (very expensive)
Short term to prevent ischemic events

Question 15

Vorapaxar MOA

Answer 15

Blocks PAR-1 receptor

Question 16

Vorapaxar clinical use

Answer 16

Reduce thrombosis post-MI

Question 17

How long does Vorapaxar effect last?

Answer 17

Up to 4 weeks

Question 18

Boxed warning of vorapaxar

Answer 18

Bleeding (intracranial hemorrhage)

Question 19

Antiplatelet drugs are effective against arterial/venous thrombi

Answer 19

Arterial

Question 20

Anticoagulants are effective against arterial/venous thrombi

Answer 20

Venous

Question 21

PTT is used to monitor intrinsic/extrinsic pathway anticoagulants

Answer 21

Intrinsic

Question 22

PT is used to monitor intrinsic/extrinsic pathway anticoagulants

Answer 22

Extrinsic

Question 23

Heparin inactivates ____ and ___ equally

Answer 23

Thrombin, Xa

Question 24

LMWh inactivates ___ well and ___ poorly

Answer 24

Xa, thrombin

Question 25

____ inactivates factor Xa only

Answer 25

Fondaparinux

Question 26

LMW heparin drugs

Answer 26

Enoxaparin Fondaparinux

Question 27

MOA of heparins

Answer 27

Blocks formation of fibrin

Question 28

Heparin has no intrinsic/extrinsic activity

Answer 28

Intrinsic

Question 29

Clinical uses of heparin

Answer 29

Initial treatment of DVT/PE Surgeries to prevent thrombosis

Question 30

Heparin antidote

Answer 30

Protamine sulfate (doesn’t work against fondaparinux)

Question 31

Heparin black box warning

Answer 31

Derived from pigs (cultural and allergic cautions)

Question 32

Vitamin K antagonist prototype

Answer 32

Warfarin

Question 33

MOA of vitamin K antagonists

Answer 33

Decreases vitamin K-dependent clotting factors by inhibiting VKORC1 in liver Decreases formation of fibrin

Question 34

Vitamin K antagonists have slower/faster onset than heparin

Answer 34

Slower (takes several days for full effect vs 5 minutes for heparin; heparin used until warfarin takes effect)

Question 35

Patients on warfarin should be advised to avoid excess ___ in their diet

Answer 35

Vitamin K (leafy greens, fish, alcohol)

Question 36

Warfarin depletes endogenous anticoagulants, causing an initial _____ state

Answer 36

Hyper-coagulable

Question 37

Route of administration for warfarin

Answer 37

Oral

Question 38

Warfarin is ___% albumin bound

Answer 38

99%

Question 39

Warfarin therapy requires close monitoring via ___

Answer 39

PT/INR

Question 40

Warfarin is metabolized by which enzyme?

Answer 40

CYP2C9

Question 41

Clinical use of warfarin

Answer 41

Long-term prophylaxis of venous thrombosis

Question 42

Adverse effects of warfarin

Answer 42

Bleeding Teratogen Tissue necrosis Purple toe syndrome

Question 43

Warfarin antidote

Answer 43

Vitamin K (phytonadione)

Question 44

Direct thrombin inhibitor drugs

Answer 44

Bivalirudin Dabigatran etexilate

Question 45

Dabigatran advantage over warfarin

Answer 45

Don’t need to monitor INR

Question 46

Dabigatran antidote

Answer 46

Idarucizumab

Question 47

t-PA MOA

Answer 47

Converts plasminogen to plasmin that digests fibrin