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Thrombolytic / STEMI

Alteplase (STEMI Thrombolysis)

Brand names: Actilyse

Used in: Venous Thromboembolism (DVT & PE) Stroke & TIA

Alteplase is a recombinant tissue plasminogen activator (a thrombolytic/fibrinolytic) used for acute ischaemic stroke, massive (haemodynamically unstable) pulmonary embolism, and ST-elevation myocardial infarction where primary PCI is not available. Its use is specialist- and protocol-driven.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION Cathflo ® Activase ® (Alteplase) is for instillation into the dysfunctional catheter at a concentration of 1 mg/mL. • Patients weighing ≥30 kg: 2 mg in 2 mL • Patients weighing <30 kg: 110% of the internal lumen volume of the catheter, not to exceed 2 mg in 2 mL If catheter function is not restored at 120 minutes after 1 dose of Cathflo Activase, a second dose may be instilled (see Instructions for Administration ). There is no efficacy or safety information on dosing in excess of 2 mg per dose for this indication. Studies have not been performed with administration of total doses greater than 4 mg (two 2‑mg doses). Instructions for Administration Preparation of …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2026-01-20. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Clinical monograph

How it works

It is a serine protease that converts fibrin-bound plasminogen to plasmin, which degrades fibrin and dissolves the thrombus. Its relative fibrin-selectivity localises activity to clot.

Prescribing in practice

  • Major bleeding, including intracranial haemorrhage, is the critical risk — strict exclusion criteria (recent surgery or trauma, active or recent bleeding, prior haemorrhagic stroke, bleeding disorders, uncontrolled hypertension) and tight time windows must be applied.
  • Use only within an agreed protocol with appropriate imaging, monitoring and access to neurosurgical/critical-care support; for acute ischaemic stroke, haemorrhage must be excluded on imaging and treatment given within the licensed time window.
  • Concurrent anticoagulants and antiplatelets increase bleeding risk; assess blood pressure carefully and follow local protocols for adjunctive therapy.

Monitoring

Monitor closely for bleeding and for neurological deterioration, with frequent observation of blood pressure, conscious level and vital signs during and after administration. Follow protocol-specified monitoring and imaging, and have arrangements in place to manage haemorrhagic complications promptly.

Counselling the patient

  • This is an emergency clot-dissolving treatment that carries a significant risk of bleeding, including bleeding in the brain.
  • Report immediately any severe headache, weakness, visual or speech changes, or signs of bleeding after treatment.
  • Patients and families should be made aware of the risks and benefits as part of the urgent treatment decision.

Evidence & guidelines

Thrombolysis is guideline-recommended for eligible acute ischaemic stroke and for high-risk pulmonary embolism (NICE NG128; NICE NG158).

Reference: GUSTO-1 Trial (NEJM 1993); ESC STEMI Guidelines 2023; NICE NG185; SPC Actilyse; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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