Drugs and Stroke Flashcards
What are the two types of cerebrovascular accident?
Ischemic stroke- caused by blockage.
Haemorrhagic stroke- cause by drainage or bleed in the cerebrum.
What is a fibrinolytic/thrombolytic drug?
Causes the activation of plasmin from plasminogen. Plasmin is the substance responsible for blocking the activation of firbrin (clotting factor).
Breaks down clots- however causes a risk of bleeding and haemorrahge so therefore can only be given in an ischaemic stroke.
Given intravenously.
Short acting drug- only to be given in first 3 hours of a stroke.
Non-antigenic- non-bacterial.
What are examples of thrombolytic drugs?
Alteplase
Streptokinase
Tranemic acid.
What are the actions of anti platelet drugs?
Inhibit the activation of platelets.
ADP antagonists, prevent thromboxane formation and prevent conscription of GPIIb/IIIa receptors.
Explain aspirin
Anti platelet drug.
NSAID that inhibits COX-1 the enzyme responsible for the synthesis of thromboxane.
Only effective in early onset.
Explain dipyriamole
Anti-platelet drug.
Often used in conjunction with aspirin.
Explain colpidogrel
Anti-platelet drug.
ADP antagonist.
Explain abcimimab
Antipatelet drug- IIa/IIIb antagonists
How do anticoagulants present the development and breakdown of a clot?
Exposure to damaged tissue or collagen following trauma leads to the activation of a series of clotting factors. This is known as the clotting cascade.
Anticoagulants target veins, inhibiting the activation of such factors.
Explain heparin.
An anticoagulant.
Administered i.v and activates anti-thrombin.
Fast acting dug- works instantly.
Anti-throbin inactivates thrombin (the substance required to convert fibrinogen to fibrin).
2 types- unfractionated and low molecular weight.
Drug names end in parin- Demiparin, Dalteparin.
Explain warfarin.
Administered orally.
Vit K antagonist- preventing production of Vit K reductase in liver.
Takes a day or two for effects to be seen/reversed.
Dosage dependent of diet, illness and is monitored using the international normalised ration.
Interact with NSAID causing bleed.
Explain thrombin inhibiting anti-coagulants.
Directly inhibit thrombin produced in saliva.
Stops clotting cascade.
Requires little monitoring so may be used instead of warfarin for long term patients, or in warfarin is not tolerated.
Drugs that end in bivalirudin and lepirudin.
Explain anticoagulant therapy.
In the incident of haemorrhage stoke, you have to reverse anticoagulant effect.
To reverse warfarin you must use Vit K supplement.
To reverse heparin you use protamine sulphate.
Explain antifibrinolytic therapy
Aprotinin is a haemostats agent that inhibits fibrinolysis.
