Thrombolytic Therapies Flashcards
What is haemostasis?
Process where body controls bleeding
What is thrombosis?
Process of blood clotting
What are platelets?
*produced by thrombocytes
*low count= excessive bleeding
*hight count= blood clot- stroke, pulmonary embolism
What factor triggers the final common pathway of the coagulation cascade?
Factor Xa (activated factor X)
What is the final common pathway?
Factor Xa activates prothrombin to thrombin, which activates fibrinogen to fibrin which activates factor XIIIa to form cross linked fibrin clot
How is the coagulation cascade regulated?
*plasmin- acts in fibrin
*anti-thrombin III- acts on thrombin
*tissue factor pathway inhibitor- works on factor Xa
*protein C
What is fibrinolysis?
The breakdown of clots
*primary fibrinolysis- normal bodily procedure initiating clot breakdown
*secondary fibrinolysis- therapeutics- thrombolytic therapy
What activates platelet aggregation?
*TXA2
*thrombin
*ADP
*serotonin
What anti platelets are there?
TXA2 synthesis inhibitors
*inhibits cox1 enzyme
*ASPIRIN
ADP inhibitors
*clopidogrel
*ticagrelor
What are examples of anti coagulants?
*indirect thrombin inhibitors
-apixaban
-rivaroxaban
*direct thrombin inhibitors - bind directly to active site and/or exosite
-dabigatran
*vitamin K reductase inhibitors
-warfarin- narrow therapeutic window, many drug drug interactions
What are examples of fibrinolytics and what are their main risks?
*alpha-anti 2 plasmin - binds to plasmin active site and acts as competitive inhibitor- reduces fibrin degradation
*plasminogen activator inhibitors- tPAI, uPAI
Urokinase, streptokinase
Risk of bleeding - inhibit other processes in coagulation
Limited efficacy breaking down big clots
What is a thrombectomy?
*catheter thrombectomy- blood clot removed by suction
*mechanical thrombectomy- clot broken into small pieces and removed
