Stroke Drugs Flashcards
What are the two types of stroke?
Thromboembolic infarction - blockage
Intracranial haemorrhage - damage/bleed
What is a stroke?
Rapid onset of cerebral deficit lasting more than 24 hours or leading to death - vascular cause.
What happens to the cells during a stroke?
Occlusion - cells have no blood supply, irreversible necrosis, cell bursts and contents spills into surrounding tissue.
What are the three stages of a stroke?
- Early hours - cell getting sick
- Inflammation, cells complete dying process
- Re routing pathways
What type of drug is alteplase?
Fibrinolytic drug
How does alteplase work?
Activates plasminogen which converts to plasmin and breaks down the clot
How and where is alteplase given?
Intravenously in specialist stroke units
Is alteplase short or long acting?
Short
When is alteplase only effective?
If given within the first 3 hours
What must you do before giving alteplase and how?
Must confirm it is ischaemic by CT scan or MRI
What type of drug is aspirin?
NSAID
What does aspirin do?
Inhibits COX1 and prevents thromboxane formation
How does dipyridamole work?
Inhibits thrombixane synthase, prevents thromboxane formation
How does Clopidogrel work?
Antagonise actions of ADP at plunergic ADP receptors
How does Abciximab work?
Prevents linking of platelets to fibres
What drug therapy is normally given after a stroke?
Aspirin - acutely
Given for 2 weeks
Then anti-platelet regime eg aspirin and dipyridamole or clopidogrel
How does heparin work?
Activates body’s own anti-clotting molecules, antithrombin III
How long does it take for heparin to work?
Works immediately
What are the two forms of heparin
Unfractionated and fractionated
How does warfarin work?
Acts on the liver to inhibit vitamin K reductase
What are the problems with warfarin?
Takes days to act or reverse, needs monitoring by INR, will change lots of things in blood, interacts with other drugs and food, drink etc..
