Streptokinase (STEMI Thrombolysis)

How it works

It forms a complex with circulating plasminogen that converts further plasminogen to plasmin, dissolving fibrin within the occluding coronary thrombus to restore perfusion.

Prescribing in practice

• Major bleeding, including intracranial haemorrhage, is the principal hazard, so screen carefully for absolute contraindications such as recent haemorrhagic stroke, active internal bleeding, recent major surgery or trauma, and uncontrolled severe hypertension.
• Being antigenic, it can cause allergic reactions and hypotension during infusion, and prior streptococcal exposure or previous streptokinase reduces efficacy through neutralising antibodies — so it should generally not be re-administered.
• Primary percutaneous coronary intervention is the preferred reperfusion strategy where it can be delivered promptly.

Monitoring

Monitor closely during and after the infusion for blood pressure, allergic reactions, reperfusion arrhythmias and signs of bleeding, alongside resolution of ECG changes.

Counselling the patient

• This is an emergency clot-dissolving treatment and carries a risk of serious bleeding.
• Report any new severe headache, weakness or signs of bleeding immediately.
• Inform future clinicians that you have received streptokinase, as it is generally not repeated.

Evidence & guidelines

The GISSI and ISIS-2 trials established that streptokinase reduces mortality in acute myocardial infarction, with ISIS-2 showing additional benefit when combined with aspirin.