Stroke Flashcards
Antiplatelet
(Clopidogrel)
MOA: The active metabolite of the clopidogrel (thienopyridines) irreversibly bind to the platelet P2Y12 receptor and inhibits platelet aggregation for the life of the platelet.
Indicated: Ischaemic stroke or High risk TIA
Precautions: CYP2C19 poor metabolisers - efficacy of clopidogrel may be decreased consider an alternative antiplatelet drug.
Side effects: Bleeding, skin reaction
Dose: 75mg (1 tablet) once daily)
Time to max effect is 7 days
Counsel:
- Avoid grapefruit juice as it may decrease efficacy of clopidogrel
Aspirin
MOA: Inhibits platelet aggregation by irreversibly inhibiting COX-1, reducing the synthesis of thromboxane and inducer of platelet aggregation.
Precaution: >75yrs take aspirin have an increased risk of major bleeding
Side effect: GI irritation, increased bleeding time
Dose
- Initial Ischaemic stroke, high risk TIA = 150-300mg once daily
- Long term 75mg - 100mg once daily
Thrombolytic (Rt-PA)
(Alteplase)
MOA: Binds to fibrin meshwork and converts plasminogen to plasmin (a protease which converts insoluble fibrin to soluble fibrin degradation product) breaking down the clot
Precaution
- Risk of bleeding
- Tx with ACEI may increase risk of allergic reaction
- Elderly >80 use of alteplase is associated with poorer outcome and risk of intracranial hemorrhage and death
Side effect: bleeding, intracerebral bleeding, itnernal bleeding, transient hypotension
Counsel
- Given within 405hrs of onset of symptoms or local protocol can be given up to 9 hours
