Antiplatelet Drugs, Anticoagulants And Fibrinolytics Flashcards Preview

Basic Haemotology (1204) > Antiplatelet Drugs, Anticoagulants And Fibrinolytics > Flashcards

Flashcards in Antiplatelet Drugs, Anticoagulants And Fibrinolytics Deck (159):
1

What is activated partial thromboplastin time (PPT)

Laboratory test used to monitor the anticoagulant effect of unfractionated heparin and direct thrombin inhibitors

2

What is antithrombjn III

An endogenous anticlotting protein that irreversibly inactivates thrombin and factor Xa.

3

What are the names of the glycoproteins on the Platelet surface

Glycoprotein 2b/3a

4

How do glycoproteins primarily aggregate platelets

Binding to fibrin

5

What is the weight of unfractionated heparin

5000-30,000

6

What is the weight of fractionated heparin

2000-6000

7

What is the prothrombin time (PT)

Laboratory test used to monitor the anticoagulant effect of warfarin

8

What is in the Virchows triad

Endothelial injury
Abnormal blood flow
Hypercoagulability

9

What are the three types of anticlotting drugs

Anticoagulants
Thrombolytics
Anti platelets

10

What drugs facilitate clotting

Replacement factors, Vitamin K, Antiplasmin drugs

11

List the drugs associated with anticoagulants

Heparin
Direct thrombin inhibitors
Direct factor Xa inhibitors
Warfarin

12

List the drugs associated with thrombolytics

Tissue Plasminogen Activator (tPA derivative)
Streptokinase

13

List the drugs associated with anti platelets

Aspirin
Glycoprotein 2b/3a inhibitors
Adenosine diphosphate inhibitors
Phosphodiestrase (PDE)/ adenosine reuptake inhibitors

14

What pathway does
I heparin
II warfarin
target

Intrinsic
Extrinsic

15

What is the MOA of
I Heparin
II Warfarin

Inactivates thrombin and factor Xa
Inhibits Synthesis if clotting Factors

16

What is the route of administration for
I Heparin
II Warfarin

IV or SubQ
PO

17

True or false Heparin crosses the placenta or into breast milk but Warfarin doesn’t

False, Warfarin crosses the placenta (teratogenic) but Heparin doesn’t

18

How long is the offset of
I Heparin
II Warfarin

Rapid (minutes)
Slow (hours)

19

How long is the duration of
I Heparin
II Warfarin

Brief (hours)
Prolonged (days)

20

True or false Heparin has lesser drug interactions than Warfarin which has many

True

21

How is
I Heparin
II Warfarin

Eliminated

Renally
Hepatically

22

What is used to monitor
I Heparin
II Warfarin

PTT
PT

23

What is the antidote for
I Heparin
II Warfarin

Protamine
Phytomenadione (Vitamin K)

24

What are the low molecular weight anitthrombin III activators

Enoxaparin
Dalteparin

25

What are the Vitamin K antagonists

Warfarin
Phenprocoumon (Acenocoumarol)

26

What are the drugs associated with being thrombin inhibitors

Hirudin
Argatroban
Bivalirudin
Davila Tran
Desirudin
Lepirudin

27

What are the drugs associated with being Heparin and LMWH

Heparin
Ardeparin
Dalteparin
Danaparoid
Exoxaparin
Tinzaparin

28

What are the drugs associated with being Direct Factor Xa inhibitors

Apixaban
Edoxaban
Rivaroxaban

29

What is the source of injectable heparin and LMWH

Procine intestinal mucosa
Bovine lung

30

Heparin and LMWH is associated with the family of _______ ________

Sulphated glycosaminoglycan

31

What is the molecular weight range of injectable heparin

5000-40000 daltons

32

What is the molecular weight of LMWH

1000-10,000 daltons using gel filtration chromatography

33

What is the MOA of Heparin

Cofactor of Antithrombin III
Increases the rate of ANTIII reaction by 1000
Also increase in activation of IX, Xa, XIa, XIIa and protein C and S
1:10 binding ration with all factors

34

What is the MOA of LMWH

Have only one binding site for ANTI- III
Therefore increase inactivation of IX, Xa, XIa and XIIa

35

True or false, only the LMWH is active in the invivo and in vitro method

False both Heparin and LMWH

36

True or false , LMWH doesn’t inactivate IIa

True

37

True or false, only long chains of Heparin can inhibit the action of factor Xa by binding to antithrombin (AT)

False, any size heparin chain can inhibit the factor Xa

38

True or false, in order to inactivate thrombin (IIa), the heparin molecule must be long enough to bind to both antithrombin and thrombin

True, it must be long in order to bind to both antithrombin and thrombin

39

What type of Heparin would you use to inactive thrombin

Unfractionated Heparin

40

LMWH binds only to ______ and therefor increases inactivation of Factors __________

Antithrombin III and IXa, Xa, XIa and XIIa

41

Why is LMWH, more prescribed than Heparin

Less monitoring
More predictable anticoagulant response
Same efficacy as heparin

42

True or false, Heparin is polar

True

43

What is the :
I. Way of Administrating
II. Onset

Of heparin

IV and subcutaneous,
Fast, 60 minutes

44

What is the bioavailability of Heparin after SC

20%

45

Why is the initial loading dose required

5000 U

46

Explain the reason as to why Heparin is unpredictable

Non-specific binding to plasma proteins, endothelial cells, Macrophages
vWF- need to saturate

47

What is the half life of Heparin

40-90 minutes

48

The aPPT for monitoring Heparin should not be

> 2.5 X normal

49

True or false, the Ti for Heparin is low

True

50

How is Heparin eliminated

Internalized and destroyed by Reticulocyte-endothelial system, heparinase enzyme

51

What are the advantages of LMWH vs UH

Less inhibition of platelet function Lower incidence of Thrombocytopenia and Thrombosis (HIT Syndrome)

52

How does the use of LMWH Lower the risk of thrombocytopenia or HIT

Less interaction with platelet factor 4
Fewer heparin- dependent lgG antibodies

53

What are the adverse drug reactions of Heparin

Inhibits aldosterone- hyperkalemia= HIT potential
Causes necrosis due to Protein C
Anticoagulant
Initial transient reduction in platelet count

54

Thrombocytopenia usually occurs 2-14 days after the start of therapy
____% patients receiving heparin
____% patients receiving LMWH

5%
1%

55

HIT Incidence rates for
Thrombosis
Amputations
Death

30-50%
20%
30%

56

What is used during Heparin Overdose

Protamine sulphate

57

How is Protamine sulphate given

Slow IV
Given at 1Mg/ 100 U of heparin remaining

58

Protamine sulphate is given routinely after________ surgery to reverse effects of Heparin

Cardiac

59

What is the adverse effects of Protamine Sulphate

Histamine release

60

True or false, Heparin and LMWH are both given at 5000 U

True

61

What is the bioavailability of LMWH after SC

90%

62

What is the half life of LMWH

T times longer than heparin

63

Why is there no monitoring required for LMWH

There is no change in aPTT

64

True or false, Heparin is more expensive than LMWH

False LMWH is more expensive

65

What is the difference between the Thrombin inhibitor drugs and heparin drugs

Heparin drugs require the binding of Antithrombin III in order to inhibit the binding of Thrombin

66

What are the names of the Thrombin inhibitor drugs that are taken via IV

Hirudin
Lepuridin

67

What is the name of the Thrombin inhibitor that is taken orally

Dinihatran etexilate

68

True or false , Thrombin inhibitors are approved for treatment of anticoagulant when there is or the potential for HIT

True

69

How is hirudin produced

Synthesized via recombinant DNA technology

70

How is Hirudin eliminated

Hepatic metabolism

71

What is the half life of hirudin

2 and a third hours

72

What are the adverse effects of Hirudin

Liver injury, Renal insufficiency

73

True or false, Heparin blocks the activation of Clotting factors while Warfarin speeds up the inactivation of The clotting Factors

False, it is the other way around

74

What is the oral coagulant for warfarin

Coumarin

75

Where is Coumarin prepared from

Clover leaves

76

What is the MOA of Warfarin

Competively inhibits the Vitamin K epoxide reductase complex 1 (-VPORC1), which is essential for activating the Vitamin K available in the body
Through this method, Warfarin can deplete functional Vitamin K reserves and therefore reduce synthesis of active clotting Factors

77

What is the half life for Warfarin in cofactors (hrs)
VII
IX
X
II
Protein C
Protein S

6
24
36
60
8
30

78

Where is Warfarin eliminated and by what enzyme

Liver CYTP450

79

Is Warfarin polar or non polar

Non polar

80

What is the onset of Warfarin

Slow - 48 hours

81

What is the duration of Warfarin

4-5 days

82

What is the half life range of Warfarin

25-60 hours

83

True or false, Warfarin is well absorbed

True pK 2-8 hours

84

What Aretha ADR/ toxic effects of Warfarin

Diarrhea
Overdose - bleeding
Skin necrosis
Drug interactions

85

What is used to treat Warfarin

Vitamin K

86

True or false, Warfarin has a low TI

True

87

What is the therapeutic range of warfarin

2-3

88

What is the
i. onset of plasma in the reversal of warfarin
ii. duration

Rapid but short lasting

89

What is the onset of Vitamin K in the reversal of of warfarin
ii. duration

Vitamin K- not rapid but lasts 1-2 weeks

90

True or false, It is advised to use vitamin k if you are planning on restarting warfarin within next week

false

91

Warfarin Induced Skin Necrosis usually occurs in what range after initiation

3-6 days

92

True or false, Warfarin induced skin necrosis is common

False it is rare

93

What persons are most likely to be affected by Warfarin Induced skin necrosis

Obese women
Postmenopausal women

94

What is the treatment for Warfarin induced skin necrosis

Heparin

95

Which drug inhibits liver enzymes

Cimetidine

96

Cimetidine ______ clearance of Warfarin

Decreases

97

What drugs increase the clearance of Warfarin

Barbiturates, rifampin, phenytoin

98

Which drugs induces liver enzymes

Barbiturates, rifampin, phenytoin

99

How does Disulfiram affect interactions with Warfarin

Causes Displacement from plasma proteins, thereby increasing free warfarin

100

How does Broad Spectrum Antibiotics affect drug interaction with Warfarin

Decrease absorption of Vitamin K, decreases clotting factors
Increases Warfarin activity

101

What type of Anti-clotting drug decreases the formation of chemical signals that promote platelet aggregation

Antiplatelet drugs

102

Anti platelet drugs are mainly administer for what specific cases

Specific Prophylaxis of arterial thrombosis
During management of heart attacks

103

What are the different types of antiplatelet drugs

COX/TXA2 inhibitor
IIB/IIIA receptor antagonists
P2Y12 ADP receptor blockers
Phosphodiesterase Inhibitor

104

What are the different P2Y12 ADP receptor blockers

Ticlopidine
Clopidogrel
Prasugrel
Ticagrelor

105

What are the different IIB/IIIA receptor antagonists

Abciximab
Eptifibatide
Tirofiban

106

What are the different phosphodiesterase inhibitors

Dipyridamole

107

What is the name of a COX/TXA2 inhibitor

Aspirin

108

TXA2 is a potent inducer of platelets _________

Aggregation

109

Aspirin acetylates ________ inhibiting platelet aggregation for a range of _________ days

Cyclooxygenase-1 (COX-1)
5 or 7 days

110

What is the MOA of aspirin

irreversible inhibition of COX 1
In platelets prevents formation of TX A2 which prevents platelet aggregation

111

What is the oral Dose of Aspirin

160-320mg/d

112

What is the onset of Aspirin

30-60 mins

113

Where is Aspirin eliminated

Liver

114

What is the duration of Aspirin

7-9 days

115

What is the adverse reaction of Aspirin

GIT irritation

116

What is the MOA of Dipyridamole

Inhibits phosphodiesterase = cAMP
cAMP competes with ADP for binding site = blocking response to ADP
High amounts of AMP decreases Ca2+ concentration, therefor decreasing aggregation of platelets

117

What is Dipyridamole usually used with

Aspirin or Warfarin

118

In ______ doses, Dipyridamole can be used as a vasodilator

High

119

Dipyridamole has a _____ efficacy

low

120

What is Dipyridamole used for

Prophylactic use

121

How is Dipyridamole excreted

Liver metabolizes and then is excreted by bile

122

True or False, Dipyridamole is well absorbed

True

123

What is the adverse effects of Dipyridamole

Headaches, Dizziness
Overdoses= hypotension

124

True or false, Dipyridamole has a high PPB

True

125

What is the PK of Dipyridamole

75 minutes

126

What are the ADP receptor antagonists

Ticlopidine (Ticlid)
Prasugrel
Clopidogrel (Plavix)
Ticagrelor

127

True or False, Dipryidamole doesn't affect bleeding time

True

128

True or False, ADP receptor antagonists don't affect bleeding time

False, they do

129

Dipyridamole inhibits the reuptake of _______

Adenosine

130

ADP receptor antagonists work by inactivating the platelet _______ by irreversibly binding to the receptor, thus having a prolonged action

P2Y12 (ADP)

131

ADP receptor antagonists work by inhibiting the binding of _______ (factorI) to activated platelet

Fibrinogen

132

What is the route of administration for Clopidogrel

Oral

133

What is the PK of Clopidrogrel

2 hours

134

What is the Pro-drug activated by

CYP450 (2C19)

135

What is the onset of Clopidrogel

4-8 days

136

What is the duration of Clopidrogel

14 days

137

What is ADR of Clopidrogrel

Diarrhea, bleeding

138

What is the MOA of GPIIb/IIIa receptor antagonist

Blocks the binding of fibrinogen and Von Wilebrand Factor to the glycoprotein IIb/IIIa on the surface of the platelet.

139

What is the monoclonal antibody to the Glycoprotein IIIa/IIb

Abcixmab

140

What are the platelet IIb/IIIa antagonists

Eptifibatide, Tirofiban

141

GPIIb/IIIa antagonists increase the risk of bleeding, particularly at the site of _______

Arterial access

142

True or false, Abcixmab irreversibly binds to the GPIIb/IIIa

True

143

Abcixmab is used with _______

Aspirin and Heparin

144

What is the route of administration for Abcixmab

IV fusion

145

What is the onset of Abcixmab

rapid

146

What is the half life of Abcixmab

10 minutes

147

What is the duration of Abcixmab

48 hours

148

What are the adverse effects of Abcixmab

Fever headaches, thrombocytopenia

149

Where is Abcixmab metabolized

Liver

150

What are the Thrombolytic Drugs

Streptokinase

151

What drugs are used to lyse already formed clots

Thrombolytic drugs

152

What are two tissue- plasminogen activators

Reteplase, Tenecteplase
(more expensive)
(Only used in emergency setting )

153

What is the MOA of Fibrinolytic drugs

Increase the conversion of plasminogen to plasmin
(only used in emergency setting)

154

What is streptokinase dependent on

Plasminogen Availability

155

What is streptokinase given with

Hydrocortisone IV

156

What is the half life of streptokinase

40-80 hours

157

What is the duration of streptokinase

12 hours

158

What is the adverse effects of Fibrinolytics

Antibody formation

159

Where are Fibrinolytics metabolized

Liver