08.1 Antiplatelet, Anticoagulant & Thrombolytic Therapy Flashcards
What woud you use for an arterial (white) clot?
Antiplatelets + Thrombolysis
What would you use for a venous (red) clot?
Anticoagulation
What is Virchow’s triad?
Flow
Endothelial damage
Blood Constituents
What are some examples of anticoagulants?
Warfarin
Heparin
How does warfarin work?
Antagonises Vit K to prevent synthesis of factors II (prothrombin), VII, IX and X
Why is warfarin initially procoaguable?
Blocks protein C + S
What are some ADRs of warfarin?
Bleeding
Teratogenic
What can potentiate warfarin?
Inhibiting hepatic metab (CYP inhibitors)
Inhibiting platelet fuction (aspirin)
Reducing vit K from gut bacteria (cephalosporins)
Displacement from plasma proteins (NSAIDs)
What can inhibit warfarin?
CYP inducers
How is warfarin reversed?
Vit K administration - slow
Frozen fresh plasma/clotting factors - fast
How does heparin work?
Unfractionated - stimulates antithrombin III and inhibits 10a
LMWH - inhibits 10a
What are some ADRs of heparin?
Bleeding/bruising
Thrombocytopaenia
Osteoporosis (long term)
How is heparin reversed?
Protamine sulphate
What are some examples of antiplatelets?
Aspirin, clopidogrel, dipyridamole
How does aspirin work?
Inhibits COX and therefore platelet thomboxane A2 decreases
How does dipyridamole work?
Inhibits phosphodiesterase and therefore thromboxane A2 decreases
How does clopidogrel work?
Antagonises ADP receptor (a stimuli for platelet aggregation)
What are some examples of thrombolytic therapy?
Alteplase
Reteplase
Streptokinase
How does alteplase work?
Generates plasmin which breaks down fibrin clots
How does streptokinase work?
Activates plasminogen
What is peculiar and important about use of streptokinase?
Can only be used once as the body forms antibodies against it
When can thrombolysis be used?
In an MI if PCI is unavailable
In ischaemic stroke
Major DVT + PE
What are some ADRs of thrombolysis?
Haemorrhage (GI/cerebral)
Hypotension
Hypersensitivity
