Thrombolytic Pregnancy: Limited data in pregnant women. Non-clinical studies at doses higher than human doses showed foetal immaturity and/or embryotoxicity secondary to the known pharmacological activity; alteplase is not considered teratogenic. In an acute life-threatening disease the benefit has to be evaluated against the potential risk. Breastfeeding: it is unknown whether alteplase is excreted into human milk — exercise caution and decide whether breastfeeding should be discontinued for the first 24 hours after use.

Alteplase (tPA)

Brand names: Actilyse

Alteplase (recombinant tissue plasminogen activator, tPA) is a thrombolytic given intravenously for the treatment of acute ischaemic stroke within the licensed time window.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 0.9 mg/kg body weight (maximum 90 mg) — 10% of the total dose as an initial intravenous bolus, immediately followed by the remainder infused intravenously over 60 minutes

Route: Intravenous (bolus then constant rate infusion)

Frequency: Single treatment course

Max: 90 mg total dose

Acute ischaemic stroke. Treatment must only be performed under the responsibility and follow-up of a physician trained and experienced in neurovascular care, and must be started in adults and adolescents aged 16 years and over as early as possible and no later than 4.5 hours after last known well, after exclusion of intracranial haemorrhage by appropriate imaging. The treatment effect is time-dependent — earlier treatment increases the probability of a favourable outcome; beyond 4.5 hours after symptom onset there is a negative benefit-risk ratio and it should not be given. Using the recommended standard concentration of 1 mg/mL, the volume in mL to be administered equals the dose in mg; the SPC provides a full weight-to-dose table from 40 kg (36.0 mg total, 3.6 mg bolus, 32.4 mg infusion) to 100 kg or more (90.0 mg total, 9.0 mg bolus, 81.0 mg infusion). Adjunctive therapy: intravenous heparin or platelet aggregation inhibitors such as acetylsalicylic acid should be avoided in the first 24 hours after treatment because of increased haemorrhagic risk (safety and efficacy of concomitant use within 24 hours have not been sufficiently investigated). The 2 mg vial of alteplase is NOT indicated in acute ischaemic stroke (risk of massive under-dosing) — only 10 mg, 20 mg or 50 mg vials. Standard resuscitation equipment and pharmacotherapy should be available. Monitor for angio-oedema during and for up to 24 hours after infusion. Other indications in the same SPC (different regimens — do not confuse): acute myocardial infarction, accelerated 90-minute regimen within 6 hours of symptom onset (body weight ≥65 kg: 15 mg IV bolus, then 50 mg infused over 30 minutes, then 35 mg over 60 minutes to a maximum total of 100 mg; <65 kg: 15 mg bolus, then 0.75 mg/kg over 30 minutes, then 0.5 mg/kg over 60 minutes); acute myocardial infarction 3-hour regimen when started 6-12 hours after onset (≥65 kg: 10 mg bolus, 50 mg over the first hour, 40 mg over 2 hours to a maximum of 100 mg; <65 kg: 10 mg bolus then infusion over 3 hours to a maximum total of 1.5 mg/kg); acute massive pulmonary embolism (≥65 kg: 10 mg IV bolus over 1-2 minutes then 90 mg infused over 2 hours to a maximum total of 100 mg; <65 kg: 10 mg bolus then infusion over 2 hours to a maximum total of 1.5 mg/kg, with heparin started or resumed when aPTT is less than twice the upper limit of normal and adjusted to keep aPTT 50-70 seconds).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to alteplase or to any of the excipients
Situations associated with a high risk of bleeding: significant bleeding disorder now or within the past 6 months; known haemorrhagic diathesis; manifest or recent severe or dangerous bleeding; any history of central nervous system damage (neoplasm, aneurysm, intracranial or spinal surgery); recent (<10 days) obstetric delivery or puncture of a non-compressible vessel; severe uncontrolled arterial hypertension; bacterial endocarditis or pericarditis; acute pancreatitis; active ulcerative gastrointestinal disease, oesophageal varices, known arterial aneurysm or arterial/venous malformation; neoplasm with increased bleeding risk; severe liver disease including hepatic failure, cirrhosis, portal hypertension and active hepatitis; major surgery or significant trauma in the past 3 months
Acute ischaemic stroke — additional: minor neurological deficit or symptoms rapidly improving before start of infusion; severe stroke clinically (e.g. NIHSS >25) and/or on imaging; known history of or suspected intracranial haemorrhage; evidence of intracranial haemorrhage on CT; symptoms suggestive of subarachnoid haemorrhage even with a normal CT
Acute ischaemic stroke — additional: effective anticoagulation (e.g. vitamin K antagonist with INR >1.7); heparin within the previous 48 hours with a thromboplastin time above the laboratory upper limit of normal; platelet count below 100,000/mm3
Acute ischaemic stroke — additional: any history of prior stroke with concomitant diabetes; prior stroke within the last 3 months; systolic BP >185 mmHg or diastolic BP >110 mmHg (or BP not reducible below these limits by careful management); blood glucose <50 mg/dL (<2.8 mmol/L) or >400 mg/dL (>22.2 mmol/L)
Not indicated for the treatment of acute ischaemic stroke in children and adolescents (SPC statement truncated in this source extract — confirm the exact age wording; §4.2 restricts treatment to adults and adolescents aged 16 years and over)

Side effects

Haemorrhage (very common) — the most frequent adverse reaction, in various forms, with a fall in haematocrit and/or haemoglobin; intracerebral haemorrhage is the major adverse reaction in the treatment of acute ischaemic stroke
Common haemorrhages: pharyngeal, gastrointestinal (gastric, ulcer, rectal, haematemesis, melaena, mouth, gingival), ecchymosis, urogenital (haematuria, urinary tract), injection/puncture/catheter site haemorrhage
Uncommon: pulmonary haemorrhage (haemoptysis, haemothorax, respiratory tract), epistaxis, ear haemorrhage; rare: eye haemorrhage, pericardial haemorrhage, retroperitoneal bleeding
Hypersensitivity reactions (rare) — rash, urticaria, bronchospasm, angio-oedema, hypotension, shock; serious anaphylaxis (very rare). Angio-oedema is the most common hypersensitivity reaction
Nervous system events (very rare) — epileptic seizure, convulsion, aphasia, speech disorder, delirium, acute brain syndrome, agitation, confusion, depression, psychosis, often in association with concurrent ischaemic or haemorrhagic cerebrovascular events
Cardiac (in the myocardial infarction indication): recurrent ischaemia/angina, hypotension, heart failure/pulmonary oedema (very common); cardiogenic shock, cardiac arrest, reinfarction (common); reperfusion arrhythmias (uncommon)

Interactions

Intravenous heparin and platelet aggregation inhibitors such as acetylsalicylic acid — avoid in the first 24 hours after treatment for acute ischaemic stroke due to increased haemorrhagic risk (§4.2)
Other medicines affecting coagulation or platelet function — may contribute to bleeding (§4.4)
ACE inhibitors — may enhance the risk of angio-oedema, a risk already increased in the acute ischaemic stroke indication (§4.4, cross-referencing §4.5; the §4.5 interactions section was not captured in this source extract)

Clinical monograph

How it works

It is a recombinant tissue plasminogen activator that binds fibrin and converts plasminogen to plasmin, dissolving the occluding thrombus and restoring cerebral perfusion.

Prescribing in practice

Intracranial haemorrhage is the major hazard, so haemorrhagic stroke must be excluded by imaging and strict eligibility, time-window, blood-pressure and contraindication criteria applied before treatment.
It should only be given by clinicians trained in acute stroke care within an appropriate stroke pathway, after weighing time from symptom onset.
Concurrent antithrombotics are withheld for a defined period after administration.

Monitoring

Monitor neurological status, blood pressure and for signs of bleeding closely during and after the infusion.

Counselling the patient

This clot-busting treatment can improve stroke recovery but carries a risk of bleeding in the brain.
Inform the team immediately of any new headache, drowsiness or worsening weakness.
Report any bleeding, bruising or blood in urine or stool.

Evidence & guidelines

Intravenous alteplase for acute ischaemic stroke within the time window is recommended by NICE, based on the NINDS and subsequent thrombolysis trials.

Reference: NICE NG128 Stroke and TIA; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways