Tenecteplase (TNK-tPA — STEMI/Massive PE)

How it works

It is a genetically modified, fibrin-specific tissue plasminogen activator that binds fibrin within the thrombus and converts plasminogen to plasmin, dissolving the clot; its modifications give greater fibrin specificity and a longer half-life allowing single-bolus dosing.

Prescribing in practice

• Major bleeding, including intracranial haemorrhage, is the critical risk — screen carefully for absolute contraindications such as recent stroke, active internal bleeding, recent major surgery or trauma, and uncontrolled severe hypertension before giving.
• It is dosed by body weight and given as a single rapid bolus; for STEMI it is combined with antithrombotic therapy, and the labelled dose differs from that used in acute ischaemic stroke protocols.
• Concurrent anticoagulants and antiplatelets increase bleeding risk, so co-therapy and access-site management must follow the relevant reperfusion protocol.

Monitoring

Monitor for bleeding, neurological status, blood pressure, cardiac rhythm including reperfusion arrhythmias, and the ECG response to reperfusion.

Counselling the patient

• Explain this clot-busting injection is given urgently to restore blood flow.
• Report any new headache, weakness or bleeding immediately.
• Bruising and minor bleeding at puncture sites are expected.

Evidence & guidelines

Single-bolus efficacy and safety in STEMI are supported by the ASSENT trial programme; pulmonary embolism use is supported by trials such as PEITHO and reflected in resuscitation and ESC guidance.