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Pharm II MHM - FINAL > Anticoagulants > Flashcards

Flashcards in Anticoagulants Deck (56)
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1

What are the categories of antithrombotics?

-Anticoagulants
-Fibrinolytics
-Antiplatelets

2

What do anticoagulants do?

Stop clot formation and extension

3

What do fibrinolytics do (in general)?

Break up existing clots

4

What do antiplatelets do?

Decrease platelet activation and aggregation

5

What are the two types of thrombi and how do they differ?

-White thrombus (platelet rich, forms in arteries, MI)
-Red thrombus (fibrin/RBC rich, forms in veints, DVT/PE)

6

What does TXA2 do?

Vasoconstriction

7

What does vWF do?

Binds to exposed collagen fibers at the injured vessel surface

8

What does fibrinogen do?

-Forms bridges between adjacent platelets
-This results in an aggregate of platelets at the vessel injury site

9

What does thrombin (factor IIa) do?

Converts fibrinogen to fibrin (which forms the stable clot)

10

What is the final result of the coagulation cascade?

Fibrin threads create a plug to make a stable clot

11

What are the overall steps of platelet activation?

-Injury
-Collagen and vWF exposed
-Platelet adherence and activation
-Binding of fibrinogen
-Aggregation and plug formation

12

What are the mediators of platelet aggregation?

TXA2
ADP
5-HT

13

What are the pathways of the coagulation cascade and how are they activated?

-Intrinsic (activated by exposed endothelium)
-Extrinsic (activated by tissue damage)
-Common (intrinsic and extrinsic merge together)

14

What is the first step in the common pathway of coagulation?

Activation of Factor Xa

15

What is the last step in the intrinsic and extrinsic pathways of coagulation?

Activation of Factor Xa

16

What factors are necessary to form a clot?

Factor 2 (prothrombin)
Factor 10

17

What does Factor Xa do in the coagulation cascade?

Combines with Factor 2 (prothrombin) to form thrombin

18

What factors are targeted by Warfarin?

SNOT
Seven, Nine, Ten (0), Two

19

What does prothrombin time (PT) measure?

Activity of Factors 2, 7, 9, 10

20

What is INR?

-International Normalized Ratio
-Same as PT but standardized worldwide

21

What does PTT measure?

Activity of Factors 2, 5, 7, 9, 10, 11, 12

22

What is activated clotting time (ACT)?

-Same as PTT but used in invasive/operating procedures
-Quicker result turnaround

23

What are the indirect thrombin inhibitors?

Heparin
LMWH (Enoxaparin)
Fondaparinux

24

How do indirect thrombin inhibitors act as anticoagulants?

Help antithrombin deactivate clotting factors

25

Heparin inhibits which clotting factors?

X and II

26

What is HIT?

-Heparin Induced Thrombocytopenia
-Antibody mediated adverse effect of heparin
-Strong a/w thrombosis

27

What are signs of HIT?

-Platelets fall more than 50% from baseline with nadir 20,000+
-Platelets start to fall on day 5-10 of therapy
-Thrombosis occurs while on heparin
-R/o other causes of thrombocytopenia

28

What is the treatment of HIT?

-Stop heparin, treat with IV direct thrombin inhibitor
-Do NOT give platelets
-Do NOT give warfarin until platelets return to normal

29

LMWH (enoxaparin) inhibits which factors?

Factors Xa, IIa

30

When should enoxaparin dose be reduced? When should it be stopped?

-Reduced in CrCl 20-30 ml/min
-Stopped in CrCl less than 20