Fibrinolytics Flashcards
1) Give the 3 common clinical indications for the use of fibrinolytic drugs.
1) Acute ischaemic stroke, acute STEMI, massive PE with haemodynamic instability.
For each clinical indications for use of fibrinolytics, state which drug should be used and why.
1) Acute ischaemic stroke: alteplase - increases patient chance of living independently is given within 4.5h of stroke onset.
2) Acute STEMI: alteplase and streptokinase - can reduce mortality when given within 24 hours of onset in combination with anti-platelets and anticoagulants.
3) Massive PE: fibrinolytic drugs reduce clot size and pulmonary artery pressures. No clear evidence that they improve mortality.
Describe the MoA of fibrinolytic drugs.
Catalyse conversion of plasminogen to plasmin > plasmin dissolves fibrinous clots and re-canalise occluded vessels > reperfusion of affected tissue > prevents/limits tissue infarction and cell death.
1) Give 3 common adverse effects of fibrinolytic drugs.
2) Give 3 adverse effects of fibrinolytic drugs that require treatment to be stopped.
3) What might reperfusion of infarcted brain or heart tissue lead to?
1) Nausea, vomiting, bruising around injection site, hypotension.
2) Serious bleeding, allergic reaction, cardiogenic shock, CA.
3) Cerebral oedema and arrhythmias respectively.
Give the 3 main contraindications to use of fibrinolytic drugs for thrombolysis.
1) Predisposition to bleeding (recent haemorrhage, recent trauma or surgery, bleeding disorders, severe HTN, peptic ulcers).
2) Intracranial haemorrhage must be ruled out by CT in acute stroke before treatment.
3) Previous streptokinase treatment, as there could be development of anti-streptokinase antibodies.
Give 2 important interactions of fibrinolytics.
1) risk of haemorrhage increase in patients taking anticoagulants and antiplatelet agents.
2) ACE inhibitors increase risk of anaphylactoid reactions.
How are fibrinolytics usually administered and dosed?
Only available as injectable preparations. A bonus dose is usually given first, followed by an IV infusion.
Should only be administered in high dependency areas (ED, CCU, hyperacute stroke unit).
What precautions should be taken when thrombolysing a patient?
Fibrinolytics should only be administered in a high dependency unit.
Patients should have vitals checked every 15 minutes for at least 2 hours. Including observations for signs of bleeding, anaphylaxis (streptokinase) and neurological deterioration (in acute stroke).
