Fibrinolytic drugs

 

Streptokinase

IV infusion

Enzyme produced by Group C haemolytic streptococcus

Binds to plasminogen activating it to plasmin independently of fibrin

Hyperfibrinolytic effect lasts a few hours after stopping infusion, but TT remains prolonged for 24 hours.

 

Tissue Plasminogen Activator (t-PA)

Human recombinant protein

Causes fibrinolysis only at the site of vascular injury

 

Reteplase

Non-glycosylated t-PA —> longer half-life

 

Tenecteplase

Modified t-PA —> longer half-life of around 20mins (elimination time of 90-130min)

 

Urokinase

Half-life: 12 minutes

IV infusion

Obtained from human neonatal kidney cells

 

Emergency reversal of Fibrinolytics (AHA 2017)

Consider for cerebral bleeding within 24 hours of administration of fibrinolytics

—> But decision needs caution as haemorrhagic transformation of ischaemic stroke can occur in absence of thrombolysis therapy, ie the drug may not be responsible. Need input from Stroke team in assessing the appropriateness of attempting to reverse fibrinolytic effects on a patient-by-patient basis

If decide to correct the fibrinolysis:

  • Cryoprecipitate - transfuse one adult dose stat, and then as need to achieve FGN >1.5g/l

  • Tranexamic Acid - 1g IV state

  • ?Platelets - controversial but recommended if platelet count <100

  • ?PCC - controversial but consider as an adjunct treatment, particularly if recent warfarin therapy

  • ?FFP - controversial but consider as an adjunct treatment

See AHA 2017 Guideline for details