Exam 3; Agents that Affect the Clotting System Flashcards Preview

AU14 Pharmacology > Exam 3; Agents that Affect the Clotting System > Flashcards

Flashcards in Exam 3; Agents that Affect the Clotting System Deck (80):
1

The initial activation of platelets leads to what

platelet plugs

2

When ADP binds to the platelets, they activated what

glycoprotein receptors
GPIIb and GPIIIa

3

This binds to GPIIb and GPIIIa and leads to platelet aggregation

fibrinogen

4

This inhibits platelet aggregation

cAMP

5

The clot consist primarily of what

fibrin

6

All of the clotting factors are circulating proteins, and when activated become what

proteolytic enzymes

7

What does Xa stimulate

prothrombin to thrombin (IIa)

8

What two things does thrombin stimulate

fibrinogen to fibrin
activates platelets, factors VII, VIII, XIII

9

What is the purpose of fibrinogen

cross-linkning platelets

10

What is the purpose of fibrin

to form the clot

11

What does XIII to XIIIa assist in

stabilizing the clot

12

Which factors require Ca to work

XI to XIa
X to Xa
prothrombin to thrombin
fibrinogen to fibrin
XIII to XIIIa

13

What are the steps to reverse clot formation

plasminogen → plasmin → clot lysis

14

What is the step to localize clotting

antithrombin III → causes inactivation of thrombin, factors IX, X, XI, XII

15

This is a genetic disorder that causes inadequate clotting

hemophilia

16

Which is more common, too little clotting or too much clotting

too much clotting

17

This is a clot that adheres to a blood vessel wall

thrombus

18

What is it when there is a thrombus in the arteries

white thrombi

19

What is a white thrombi associated with

atherosclerotic plaques

20

What is it when there is a thrombus in the veins

red thrombi

21

What is a red thrombi associated with

pooling of blood in the extremities

22

This is when a thrombus breaks off and travels through the blood stream; it will stop one it can no longer fit through the vessels clogging it

thromboembolus

23

In which four conditions are anti-coagulates are used

thromboembolic disease
after most kinds of surgery
during transfusions
in patients with heart disease

24

What are the three calcium chelators anti-coagulates

Citric acid
EDTA
EGTA

25

Why do you generally not give people calcium chelators

due to Ca being widespread-ly used in the body; unless hypercalcemia

26

This anti-coagulate is not synthetic and is purified from animal tissues with a strong negative charge

heparin

27

What is the mechanism behind heparin

binds to anti-thrombin, a protease inhibitor

28

At low doses, what does heparin do

inhibits Xa
thus decreasing the formation of thrombin

29

At high doses, what does heparin do

inhibits thrombin, IXa, IXa, and XIIa

30

After thrombin is inactivated, heparin does what

is released and moves on to catalyze another reaction

31

True or False
Heparin is able to lyse existing clots

False; it is not

32

Heparin must be given by which method

Injection; usually subQ

33

Why can heparin not be given orally

It is such a large molecule that is will not be absorbed by the gut

34

True or False
Heparin easily passes the placenta and can cause major damage to the fetus

False; it cannot pass the placenta

35

What is the half life of heparin

1 hour; immediate onset

36

What degrades heparin

Heparinase

37

What is the dose response of heparin

It is somewhat unpredictable because it can bind to a variety of proteins

38

What is the toxicity level of heparin

Relatively non-toxic
Major toxicity is bleeding

39

What can be used to treat an overdose of heparin

Strongly positive protnine sulfate

40

What three things can result from long term use of heparin

Osteoporosis; due to lack of osteoclasts
Thrombocytopenia; loss of platelets
Hypersensitivity; because it is an animal product

41

What are two low molecular weight heparins

Enoxaparin
Dalteparin

42

What is the half live of enoxaparin and dalteparin

4 hours; longer than heparin

43

Which molecule does enoxaparin and dalteparin have more of an effect on, Xa or thrombin?

Xa

44

What are some differences between enoxaparin/dalteparin and heparin

less osteoproosis and HIT
more predictable dose response
more expensive
not readily reversed by protiminie sulfate

45

What is a side effect of enoxaparin and dalteparin

may cause spinal hematoma in patients who have had a spinal tap or spinal anesthesia

46

This is a purely synthetic heparin-like drug with a half life of 17hrs, given subQ

fondaparinux

47

What is the mechanism of fondaparinux

works only on factor Xa

48

The saliva of a leech contains this drug

hirudin; anticoagulate

49

What is the mechanism of hirudin

works by directly inhibiting thrombin

50

These are two synthetic analogs of hirudin

bivalirudin
desirudin

51

This is a peptide derived from hirudin

agratroban

52

When are the analogs of hirudin used

when the patient has heparin induced thrombocytopenia

53

What is the mechanism of warfarin

inhibition of the enzyme that allows vitamin K to be recycled
K-oagulation

54

What is vitamin K essential for

synthesis of factors VII, IX, X, and pro-thrombin

55

What is warfarin metabolized by

P450
can be affected by other drugs and grapefruit juice

56

What are three toxicities of warfarin

many drug interactions
hemorrhage
can pass the placenta (cat. X)

57

This is a pro-drug that is a direct thrombin inhibitor (enzyme inhibitors)

diabigatran

58

What are two factor Xa inhibitors (enzyme inhibitors)

rivaroxaban
apixaban

59

This is a thrombin receptor blocker

vorapaxar

60

In which type of patient do you need to be care administrating vorapaxar to

patients with a history of intracranial bleeding

61

What are four ADP inhibitors (inhibits ADP from binding to receptor)

ticlopidine
clopidogrel
prasugrel
ticagrelor

62

This ADP inhibitor can cause neutropenia and agranulocytosis

ticlopidine

63

What is the main difference between all the ADP inhibitors

pharmacokinetics

64

These are three fibrinogen receptor inhibitors

abciximab
tirofiban
eptifibatide

65

The fibrinogen inhibitors prevent what

platelet aggregation

66

The fibrinogen inhibitors can cause what

thrombocytopenia

67

Which method are the fibrinogen inhibitors given

IV

68

This is a COX inhibitor which inhibits thromboxane synthesis via cyclooxyrgenase inhibitor (enzyme inhibitor)

aspirin

69

What are two phosphodiesterase inhibitors

cilostazol
dipyradiamole

70

What is the mechanism behind cilostazol and dipyradiamole

inhibits the enzyme that breaks down cAMP (phosphodiesterase)

71

This drug decreases platelet formation, maturation, and number; decreasing platelet count

anagrelide

72

What are three contradictions for oral anti-coagulants

anyone with a bleeding disorder
severe hypertension
after surgery in the eye, brain, or spinal cord

73

Why is anyone with a bleeding disorder, contraindicative of oral anti-coagulants

could have a hidden bleeding disorder; 25% of all deaths due to GI bleeding were because they didn't know it

74

Why is anyone with hypertension, contraindicative of oral anti-coagulants

small vessels are damaged and if you remove the clotting mechanism then you will "sprout leaks"

75

What are three agents that dissolve formed clots

streptokinase
urokinase
tissue plasminogen activator

76

What is the mechanism behind streptokinase, urokinase, and tissue plasminogen activator

converts plasminogen to plasmin

77

plasmin hydrolyzes fibrin and degrade what

fibrinogen and factors V and VII

78

When will you use the agents that dissolve formed clots

if someone ocomes into the hospital having a heart attack due to a clot; given IV

79

What is the mechanism behind hemostatic agents

inhibits plasminogen activation (enzyme inhibitor)

80

What are the two hemostatic agents

aminocaproic acid
tranexamic acid