Thrombosis

Question 1

How does unfractionated heparin work?

Answer 1

Binds antithrombin

Potentiating formation of antithrombin-coagulation factor complex(Xa and IIa)

Question 2

What indirect thrombin inhibitor can be given to avoid HIT?

Answer 2

Fondaparinux

Question 3

What is the mechanism for Fondaparinux?

Answer 3

Synthetic polysaccharide that binds active site of antithrombin, inhibits Xa

Question 4

What is the mechanism of LMWH?

Answer 4

Same as unfractionated heparin except, they inhibit thrombin less effectively

Question 5

What are the LMWH?

Answer 5

Dalteparin
Enoxaparin
Tinzaparin

Question 6

The effects of indirect thrombin inhibitors can be reversed with?

Answer 6

Protamine

Exception is Fondaparinux

Question 7

What is one of the advantages of LMWH?

Answer 7

Longer half-life than heparin

Question 8

What is the target value for PTT?

Answer 8

2-2.5x normal value

Question 9

What are the indirect thrombin inhibitors?

Answer 9

Unfractionated heparin
Dalteparin
Enoxaparin
Tinzaparin
Fondaparinux

Question 10

What drug class in warfarin?

Answer 10

Vitamin K antagonist

Question 11

What is the mechanism for warfarin?

Answer 11

Blocks vitamin K-dependent gamma carboxylation of factors II, VII, IX, X, Protein C & S
(does not affect already synthesized factors)

Question 12

What is the therapeutic use of warfarin?

Answer 12

Long-term anticoagulation

Question 13

Why must you use heparin with warfarin therapy?

Answer 13

Thrombosis(protein C depression) –> skin necrosis –> use heparin

Question 14

Warfarin is monitored by?

Answer 14

PT/INR

Question 15

Why is warfarin contraindicated in pregnancy?

Answer 15

Because warfarin is a teratogen

Question 16

Barbiturates are contraindicated with warfarin therapy because?

Answer 16

They enhance metabolism of induce P450, this leads to a lower PT.

Question 17

What are the direct thrombin inhibitors?

Answer 17

BAD
Bivalirudin
Argatroban
Dabigatran
They don't require antithrombin III to work

Question 18

How do the direct thrombin inhibitors work?

Answer 18

Inactivate fibrinogen-bound and unbound thrombin
Irreversible(Bivalirudin)
Reversible(Dabigatran)

Question 19

Which direct thrombin inhibitor doesn’t require PT or INR? And why?

Answer 19

Dabigatran

Renal fixed dose clearance

Question 20

What is Dabigatran used to treat?

Answer 20

DVT
PE
Atrial fibrillation

Question 21

What are Bivalirudin and Argatroban used to treat?

Answer 21

Percutaneous coronary intervention

Question 22

Which direct thrombin inhibitor can be used to avoid HIT?

Answer 22

Argatroban

Question 23

Name the direct Xa inhibitor?

Answer 23

RivaroXAban

ApiXAban

Question 24

What is the mechanism for direct Xa inhibitors?

Answer 24

Reversible bind active site of Xa

Question 25

What do direct Xa treat?

Answer 25

DVT/PE prophylaxis

Question 26

Name the fibrionolytic?

Answer 26

-PLASE lyse those clots Alteplase(TPA) Reteplase Tenecteplase

Question 27

How do fibrinolytics work?

Answer 27

They lyse already formed clots by activating circulating plasminogen

Question 28

What are fibrinolytics used to treat?

Answer 28

Acute MI Acute stroke Multiple PE Central DVT

Question 29

What are the antiplatelets drugs?

Answer 29

``` Aspirin Dipyridamole Clopidogrel Abciximab Eptifibatide Tirofiban ```

Question 30

What is the mechanism of EptiFIBatide and TiroFIBan(antiplatelet)

Answer 30

Fibrinogen analog which competes with endogenous fibrinogen for IIb/IIIa

Question 31

What is the mechanism of abciximab?

Answer 31

Monoclonal antibody against GpIIb/IIIa

Question 32

What is the mechanism of Clopidogrel?

Answer 32

Inhibits platelet ADP receptors

Question 33

What is the mechanism of Dipyridamole?

Answer 33

PDE inhibitor --> increase platelet cAMP

Question 34

Clopidogrel and aspirin are used to prevent & treat?

Answer 34

MI ACS Stroke

Question 35

How can you reverse the effect of clopidogrel?

Answer 35

Platelet transfusion