Antiplatelet Drugs, Anticoagulants And Fibrinolytics Flashcards
1
Q
What is activated partial thromboplastin time (PPT)
A
Laboratory test used to monitor the anticoagulant effect of unfractionated heparin and direct thrombin inhibitors
2
Q
What is antithrombjn III
A
An endogenous anticlotting protein that irreversibly inactivates thrombin and factor Xa.
3
Q
What are the names of the glycoproteins on the Platelet surface
A
Glycoprotein 2b/3a
4
Q
How do glycoproteins primarily aggregate platelets
A
Binding to fibrin
5
Q
What is the weight of unfractionated heparin
A
5000-30,000
6
Q
What is the weight of fractionated heparin
A
2000-6000
7
Q
What is the prothrombin time (PT)
A
Laboratory test used to monitor the anticoagulant effect of warfarin
8
Q
What is in the Virchows triad
A
Endothelial injury
Abnormal blood flow
Hypercoagulability
9
Q
What are the three types of anticlotting drugs
A
Anticoagulants
Thrombolytics
Anti platelets
10
Q
What drugs facilitate clotting
A
Replacement factors, Vitamin K, Antiplasmin drugs
11
Q
List the drugs associated with anticoagulants
A
Heparin
Direct thrombin inhibitors
Direct factor Xa inhibitors
Warfarin
12
Q
List the drugs associated with thrombolytics
A
Tissue Plasminogen Activator (tPA derivative)
Streptokinase
13
Q
List the drugs associated with anti platelets
A
Aspirin
Glycoprotein 2b/3a inhibitors
Adenosine diphosphate inhibitors
Phosphodiestrase (PDE)/ adenosine reuptake inhibitors
14
Q
What pathway does
I heparin
II warfarin
target
A
Intrinsic
Extrinsic
15
Q
What is the MOA of
I Heparin
II Warfarin
A
Inactivates thrombin and factor Xa
Inhibits Synthesis if clotting Factors
16
Q
What is the route of administration for
I Heparin
II Warfarin
A
IV or SubQ
PO
17
Q
True or false Heparin crosses the placenta or into breast milk but Warfarin doesn’t
A
False, Warfarin crosses the placenta (teratogenic) but Heparin doesn’t
18
Q
How long is the offset of
I Heparin
II Warfarin
A
Rapid (minutes)
Slow (hours)
19
Q
How long is the duration of
I Heparin
II Warfarin
A
Brief (hours)
Prolonged (days)
20
Q
True or false Heparin has lesser drug interactions than Warfarin which has many
A
True
21
Q
How is
I Heparin
II Warfarin
Eliminated
A
Renally
Hepatically
22
Q
What is used to monitor
I Heparin
II Warfarin
A
PTT
PT
23
Q
What is the antidote for
I Heparin
II Warfarin
A
Protamine
Phytomenadione (Vitamin K)
24
Q
What are the low molecular weight anitthrombin III activators
A
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
