Thrombolytic therapies
0.0 / 5
- Created by: Rscottqub
- Created on: 05-03-20 17:14
Haemostasis
the normal process which controls bleeding
1 of 51
thrombosis
the clotting process which becomes pathological if haemostasis is dysfunctionL
2 of 51
embolus
if a clot breaks off
3 of 51
embolism
when a clot blocks a vessel
4 of 51
factors affecting haemostasis and thrombosis (4)
1. vascular wall integrity 2. platelet response 3. blood coagulation cascade 4. fibrinolysis
5 of 51
how does damage occur
physical injury, oxidative stress, cancer, chronic inflammation
6 of 51
General clot sequence
1. injury 2. vessels contract 3. platelet plug forms 4. fibrin clot formation
7 of 51
vessel contraction
vascular spasm results in contriction- decreases blood flow and reduced blood lost from the site
8 of 51
platelet plug formation
most important stage, platlets activated- aggregate and bind to damaged endothelium and form temp platlet plug.
9 of 51
fibrin clot formation
prothrombin is converted to active thrombin - thrombin then converts fibrinogen to fibrin
10 of 51
solubilty of fibrin and fibrinogen
fibrin - insol. Fibrinogen = soluble
11 of 51
Platelet life span
5-9 days
12 of 51
platelets also secrete
clotting factor
13 of 51
clotting factor role
converts prothrobin into thrombin
14 of 51
In the coagulation cascade serine protease may exist in
active or inactive form
15 of 51
active form
has the suffic 'a'
16 of 51
co factors in the BCC
tissue factor, factor VIII and Va
17 of 51
3 pathways in BCC
Intrinsic , extrinsic and the final common pathway
18 of 51
how is the cascade regulated?
by inhibitors
19 of 51
inhibitor - protein C
inhibits 8a and 5a
20 of 51
inhibitor - anti thrombin
all serine protease except - 9a
21 of 51
TF inbitor
10a and 7a
22 of 51
plasmin
fibrin
23 of 51
Intrinsic pathway
for internal injury
24 of 51
extrinsic
for trauma,
25 of 51
final common
both instrinsic and extrinsic meet at factor X--> Xa
26 of 51
Types of fibrinolysis
primary and secondary
27 of 51
primary
normal clot breakdown by the body
28 of 51
secondary
theraputic clot breakdown
29 of 51
plasmin role
dissolves fibrin clots
30 of 51
plasminogen is converted to
plasmin
31 of 51
platelets have
receptors
32 of 51
upon activation by thrombin
platelets undergo conformational change - they can now aggregate
33 of 51
TXA2 synthase inhibitors
ie asprin - inhibit COX1 - prevent production of thrombin - no thrombin no clot
34 of 51
ADP inhibitors
clopidogrel
35 of 51
anticoagulants types
direct/indirect thrombin inhibitors, vit K reductase inhibitors
36 of 51
Indirect thrombin inhibitors
ie apixaban, rivaroxaban - inhibit Xa - no antidote
37 of 51
Heparin
inhibits Xa by binding to anti thrombin III, Low molecular weight heparin = enoxaparin
38 of 51
direct thrombin inhibitors - 2 types
univalent and bivalent
39 of 51
univalent
bind directly to AS of thrombin - dabigatran
40 of 51
bivalent
bind to AS and exosite of thrombin - Hirudin
41 of 51
Vit K reductase inhibitors
Vit K needed for activation of many clotting factors and prothrombin - these are inactive until reduced by vit K
42 of 51
example of vit K reductase inhibitor
warfarin
43 of 51
warfarin
antidote - vit K . many interactions needs close monitoring . narrow TW
44 of 51
primary fibrinolysis
plasminogen is cleaved -> plasmin. cleaved between Arg 561-Val562- now val can form salt bridge. this results in conformational change and now plasmin is active
45 of 51
drugs targeting fibrinolysis
1st gen - streptokinase and urokinase
46 of 51
streptokinase
binds to and activates plasminogen
47 of 51
urokinase
human enzyme found in the kidney. cleaves arg-val bond --> activating plasmiogen
48 of 51
2nd generation
pro urokinase - prodrug of urokinase
49 of 51
anistrepplase
prodrug of SK- acteylated form to protect AS
50 of 51
alteplase tissure plasminogen activator
activated plasmniogen - very short t1/2 - would need to be contantly administered
51 of 51
Other cards in this set
Card 2
Front
thrombosis
Back
the clotting process which becomes pathological if haemostasis is dysfunctionL
Card 3
Front
embolus
Back
Card 4
Front
embolism
Back
Card 5
Front
factors affecting haemostasis and thrombosis (4)
Back
Related discussions on The Student Room
Similar Pharmacy resources:
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
Comments
No comments have yet been made