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Flashcards in Stroke drugs Deck (10)
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1
Q

Stroke due to blockage

A
thromboembolic infarction (85%)
- ischaemic stroke
- blood clot stops flow of blood to the area of brain
- cerebral infarction:
> embolism from distant site
> thrombus causing occlusion
2
Q

Stroke due to damage/bleed

A

intracranial haemorrhage

  • haemorrhagic stroke
  • blood leaks into the brain
  • cerebral, cerebellar, subarachnoid haemorrhage (15%)
3
Q

Stages of development

A

interruption of blood supply = neurotoxicity = irreversible necrosis, cerebral oedema and inflammation

  1. Early hrs = cells get ‘sick’
  2. Hours to a day = inflammations cells ‘complete dying process’
  3. weeks on = re-routing pathways
4
Q

Antiplatelet Drugs

A

inhibit platelet aggregation and thrombus formation by preventing GPIIa/IIIb receptor expressionl
Aspirin -
- inhibit COX1, prevents thromboxane formation
- needs to be given in first 24hrs (300mg)
- in TIA given for 2 weeks, then ‘anti-platelet regime’ = aspirin + colpifogrel/dipyridamole
Dipyridamole -
inhibits thromboxane synthase, prevents thromboxane formation
Clopidogrel -
- antagonize actions of ADP at ADP receptors
prevents GPIIa/IIIb receptor interaction:
Abciximab -
- prevents linking of platelets to fibres

5
Q

Thrombolytic drugs

A

Alteplase (rTPA)- recombinant tissue plasminogen activators
- given i.v in specialist stroke units
- short acting
- must confirm ischaemic stroke before giving by CT/MRI scan
- only effective if given 3/4 hours within ischaemic attack
Streptokinase
Urokinase

6
Q

Anti-coagulant agents

A

clotting factors are proteins that circulate in the blood
initiated by certain factors that activate Prothrombin to activate fibrinogen to fibrin
fibrin = clot formation, traps platelets

7
Q

Anticoagulant agents - Heparin and Warfarin

A

activation of anti-thrombin eg Heparin (i.v) activates body’s own anti-clotting molecules, works immediately
inhibition of vitamin K reductase eg. Warfarin
- acts on the liver to inhibit vitamin K reductase as similar in structure to vitamin K
- gradually diminishes concentrations of clotting factors
- eventually body not able to make as much fibrin
- takes days to act
- warfarin in diet can change due to diet, drinking, acute illness, can interact with other drugs

8
Q

Other drugs in treating stroke

A

Low-molecular weight Heparin eg dalteparin

Thrombin inhibitor eg bivalirudin, lepirudin

9
Q

Long term treatment of ischaemic stroke

A
  1. anti-platelet therapy

2. secondary intervention eg. combined aspirin (75mg) and dipyridamole (200mg x2 daily)

10
Q

Reversing anticoagulation

A

Vitamin K to reverse warfarin action

urgent = give clotting factors