Pharmacology · Thrombolytics (fibrinolytics)

Alteplase !

Recombinant tissue plasminogen activator that dissolves the clot in acute ischaemic stroke, heart attack and massive pulmonary embolism.

Updated 2026-11-01

Class: Thrombolytics (fibrinolytics)
Enzyme: Plasminogen (the zymogen of plasmin), bound to fibrin
ATC code: B01AD02
WHO Model List of Essential Medicines

Also called: recombinant tissue plasminogen activator (rt-PA, t-PA)

Plasminogen (the zymogen of plasmin), bound to fibrinAlteplase

The figure shows full-length human plasminogen, the substrate that alteplase cuts into plasmin; the drug itself is not in the crystal.

Target in 3D: Plasminogen (the zymogen of plasmin), bound to fibrin. PDB structure 4DUR (RCSB PDB, public domain). View the structure at RCSB PDB

Mechanism of action

Alteplase is the human tissue plasminogen activator made by recombinant DNA technology. It is a serine protease that works poorly on free plasminogen but, once bound to fibrin, activates the plasminogen sitting on the clot far faster. The plasmin formed digests fibrin and the thrombus breaks up. At therapeutic concentrations some fibrinogen is also degraded, so haemostatic plugs elsewhere can dissolve.

The drug binds fibrin inside the clot
It cuts fibrin-bound plasminogen into plasmin
Plasmin breaks fibrin into degradation products
The artery reopens; blood flow returns

Pharmacokinetics

Distribution: Stays in the blood; acts on the clot surface
Metabolism: Cleared mainly by the liver
Half-life: About 5 minutes, so it is given as a bolus followed by an infusion

Indications

Acute ischaemic stroke, early after symptom onset and once haemorrhage has been excluded Ischaemic stroke →
Acute ST-elevation myocardial infarction when timely angioplasty is not available Myocardial Infarction (Heart Attack) →
Massive (life-threatening) pulmonary embolism Pulmonary embolism →

Adverse effects

Common

Bleeding (puncture sites, gums, urine, gut)
Bruising
Nausea and vomiting

Contraindications

Previous intracranial haemorrhage, or a known cerebral vascular lesion or brain tumour
Active bleeding or a bleeding disorder
Suspected aortic dissection
Recent ischaemic stroke, significant head trauma or brain or spinal surgery
Severe uncontrolled hypertension

Key interactions

Heparin, anticoagulants and antiplatelets (aspirin, clopidogrel): Add to the bleeding risk; serious haemorrhage is more frequent when heparin is given at the same time
Warfarin (raised INR): Current warfarin use with a raised INR is a relative contraindication

What is monitored

Neurological status and blood pressure
Signs of bleeding; haemoglobin and coagulation tests
Reperfusion: ECG and symptoms in myocardial infarction

Administration and safety

Intravenous only, prepared from a powder by trained staff
Dose is weight-based and given as a bolus plus infusion; double-check the calculation with a second person
Look-alike risk with other «-plase» drugs (tenecteplase, reteplase), which are dosed differently

Nursing care

Check the time symptoms began and go through the contraindication checklist before the drug is mixed
Neurological checks and blood pressure often during and after the infusion; a sudden headache, vomiting or a drop in consciousness suggests intracranial bleeding
Look for bleeding at puncture sites, gums, urine and stool
Avoid new arterial punctures, intramuscular injections and unnecessary venepunctures

Pregnancy and breastfeeding

Pregnancy is a relative contraindication; it is used only when the threat to the mother's life outweighs the bleeding risk.

Test yourself

Think of the answer, then tap the question to see it.

What must be excluded before alteplase in acute stroke?

Intracranial haemorrhage, with brain imaging.

Why is alteplase given as a bolus followed by an infusion?

Its half-life is only minutes.

Which drug class increases its bleeding risk most when given together?

Anticoagulants such as heparin, and antiplatelets.

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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: Alteplase Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 36 (McGraw Hill, 2023); Farmacología básica y clínica (Katzung), 16.ª ed., cap. 34 (McGraw Hill, 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.