Urokinase

Pronunciation: yoo-roh-KY-nase.

Generic name
urokinase
Drug class
Thrombolytic (fibrinolytic) enzyme
Form
Powder for solution for injection/infusion (various strengths, 10,000 IU to 500,000 IU depending on market and product)
Route
Intravenous injection/infusion, or direct instillation into a blocked catheter
Legal status
Prescription-only, hospital-administered

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada

Australia: · Full directory

What urokinase is and how it works

Urokinase is a thrombolytic medicine -- it dissolves blood clots by activating the body's own clot-breakdown system (converting plasminogen to plasmin, which digests fibrin). It is given directly into a vein or infused locally to clear a blocked blood vessel or catheter, in a hospital or specialist clinical setting only. (3) (1) (2)

Urokinase is only given to you in hospital, under close monitoring, because its biggest risk is bleeding -- including rare but serious internal bleeding such as bleeding into the brain. Its real-world availability varies significantly by country: it is a currently authorised medicine in the UK and across the EU, but it has not been commercially available in the United States or Canada for over a decade after past manufacturing and safety concerns, and it is not currently marketed in Australia either. If your clinician mentions urokinase, ask them directly whether it is the product actually available to you, since an alternative thrombolytic (such as alteplase) may be used instead where urokinase is not available.

Mechanism of action: how urokinase works

Urokinase is a serine protease that directly converts plasminogen to plasmin, the enzyme responsible for degrading fibrin clots, without requiring a fibrin-binding cofactor (unlike streptokinase, it is not antigenic in the same way, and unlike alteplase it is not fibrin-selective, which contributes to its systemic fibrinolytic/bleeding-risk profile). (3) (1)

What urokinase is used for

Acute massive pulmonary embolism

Used to dissolve a large blood clot in the lungs (pulmonary embolism) causing haemodynamic instability, to restore normal blood flow and heart/lung function. (3) (1)

Extensive acute deep vein thrombosis

Used to dissolve extensive, acute proximal deep vein thrombosis (a blood clot in a deep vein, usually of the leg). (3)

Acute occlusive peripheral arterial disease

Used to dissolve a blood clot causing acute, limb-threatening blockage of an artery in the arm or leg. (3)

Clearing blocked catheters and cannulae

Used to clear thrombosed (clot-blocked) intravascular catheters and cannulae, so they can be used again. (3)

Before taking urokinase

Do not take / not appropriate for

  • Urokinase must not be given if you have active, clinically relevant bleeding, a recent severe gastrointestinal bleed, recent major surgery, or a stroke within the past 2 months. (all countries) (3) (1)
  • Urokinase must not be given if you have severe uncontrolled high blood pressure, a known bleeding/clotting disorder, severe thrombocytopenia, an aneurysm, an arteriovenous malformation, a brain tumour, acute pancreatitis, pericarditis, bacterial endocarditis, sepsis, or have recently given birth. (all countries) (3) (1)
  • Do not receive urokinase again if you have previously had a serious allergic reaction to it. (all countries) (1)

Tell your clinician about

  • Any recent surgery, injury, dental work, or invasive procedure.
  • Any history of bleeding disorders, stomach ulcers, or previous stroke.
  • Any other medicines you take that affect bleeding, including anticoagulants (blood thinners), antiplatelet medicines (such as aspirin or clopidogrel), or NSAIDs.
  • Your age -- people over 75 have a higher bleeding risk with this class of medicine.
  • Whether you are pregnant, have recently given birth, or are breastfeeding.
  • Any known allergy to urokinase or to any of its components.
(3) (1)

How to take urokinase

  • Urokinase is given only in hospital, by injection into a vein or as an infusion, or instilled directly into a blocked catheter -- it is never self-administered or taken at home.
  • Your clinical team will monitor your blood clotting tests and watch closely for any signs of bleeding throughout treatment and for a period afterward.
  • Invasive procedures, unnecessary injections into muscle, and unnecessary handling are avoided during treatment because of the bleeding risk; if an artery is punctured (for example for a blood sample), firm pressure is applied for at least 30 minutes.
(3)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)

Missed dose

Not applicable -- urokinase is administered on an as-needed, hospital-supervised basis for an acute clot, not on a fixed take-home schedule.

Overdose

An overdose would be managed by the treating hospital team, generally by stopping the infusion and, if significant bleeding occurs, giving supportive treatment such as fresh frozen plasma or other clotting-factor replacement as directed by a specialist. There is no specific antidote that reverses urokinase's clot-dissolving effect; management is supportive and individualised. (3)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Bleeding at injection or puncture sites.

What to notice: Bleeding at injection or puncture sites.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (3)

Nosebleeds (epistaxis) or gum bleeding.

What to notice: Nosebleeds (epistaxis) or gum bleeding.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (3)

A drop in red blood cell count (haematocrit) without obvious visible bleeding, seen in around 1 in 5 people treated.

What to notice: A drop in red blood cell count (haematocrit) without obvious visible bleeding, seen in around 1 in 5 people treated.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (3)

Fever or chills.

What to notice: Fever or chills.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Signs of serious or internal bleeding — emergency

Symptoms: Unusual bruising, blood in urine or stool, black or tarry stools, coughing up blood, severe headache, sudden weakness or confusion, or fainting.

Action: Tell your clinical team immediately -- bleeding is the most frequent and most severe effect of urokinase treatment. Severe, spontaneous bleeding, including fatal bleeding into the brain, has occurred. Your care team monitors for this closely throughout treatment and can act quickly if it happens. (3) (1)

Signs of a stroke or bleeding into the brain — emergency

Symptoms: Sudden severe headache, weakness on one side of the body, difficulty speaking, vision changes, or loss of consciousness.

Action: This is a medical emergency -- call for emergency help immediately if this occurs during or after treatment. Stroke, including haemorrhagic stroke, has been reported with urokinase, particularly in people over 75 or with pre-existing cerebrovascular disease. (3)

Signs of a serious allergic reaction — emergency

Symptoms: Swelling of the face, lips, tongue, or throat; difficulty breathing; widespread hives or rash.

Action: Seek emergency medical help immediately. Anaphylaxis and other hypersensitivity reactions have been reported, though uncommonly. (3)

Interactions

  • Anticoagulants (blood thinners) such as heparin or warfarin, and antiplatelet medicines such as aspirin or clopidogrel, can increase the risk of bleeding when combined with urokinase. (1)
  • NSAIDs (non-steroidal anti-inflammatory drugs) may also add to bleeding risk. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Urokinase is generally avoided in pregnancy and is contraindicated after recent childbirth because of the bleeding risk; it would only be considered in a genuine emergency where the benefit is judged to outweigh the risk by a specialist team. (1) (2) (3) (4) (5) (6)

Breastfeeding

Specific data on urokinase in breastfeeding are limited; any decision to use it while breastfeeding would be made by a specialist weighing the clinical urgency against the theoretical risk. (1) (2) (3) (4) (5) (6)

Children

Use in children is not well established in the sources reviewed; any paediatric use would be individualised by a specialist team. (1) (2) (3) (4) (5) (6)

Elderly

People over 75 have a higher risk of bleeding, including stroke, with thrombolytic treatment -- this is factored into the specialist team's decision to treat and how closely you are monitored. (1) (2) (3) (4) (5) (6)

Hepatic_impairment

Severe hepatic insufficiency is a contraindication because of the associated bleeding risk. (1) (2) (3) (4) (5) (6)

Renal_impairment

Severe renal insufficiency is a contraindication because of the associated bleeding risk. (1) (2) (3) (4) (5) (6)

Monitoring

Before starting

  • Full blood count and coagulation studies
  • Blood pressure check
  • Review for any contraindication (recent surgery, stroke, bleeding disorder, severe hypertension)

During treatment

  • Close monitoring for any sign of bleeding, both visible and internal.
  • Coagulation studies to guide and monitor the fibrinolytic effect.
  • Blood pressure monitoring.
  • Minimising invasive procedures; prolonged direct pressure after any arterial puncture; avoiding intramuscular injections during treatment.
(3) (1)

Storage

Urokinase is stored, prepared, and administered entirely within the hospital or clinical setting under pharmacy-controlled conditions; patients do not store or handle it themselves.

Study the drug class: Thrombolytics

Professional information

Clinician-facing context only, sourced from the current UK SmPC and the archival US Kinlytic label; verify against the current full label and local availability before prescribing or administering.

United Kingdom / European Union

Indication: Acute massive pulmonary embolism / extensive proximal DVT

Dose summary: Loading dose 4,400 IU/kg over 10 minutes, then 4,400 IU/kg/hour for 12-24 hours (DVT) or 12 hours (PE); alternative PE regimen: 15,000 IU/kg bolus, repeatable up to twice at 24-hour intervals.

Renal context: Severe renal insufficiency is a contraindication. (3)

Mechanism of action

Hepatic guidance

Severe hepatic insufficiency is a contraindication due to bleeding risk.

Overdose note

No specific reversal agent; manage supportively, including fresh frozen plasma or other clotting-factor replacement if significant bleeding occurs, under specialist guidance. (3) (1)

Frequently asked questions

Is urokinase available in the US, UK, Europe, Canada, Australia, and New Zealand?

This varies significantly by country, and it is important not to assume uniform availability. It is currently authorised and marketed in the United Kingdom (as Syner-KINASE) and, via mutual EU recognition, in the European Union. It is NOT currently commercially available in the United States or Canada, where it was previously marketed (as Abbokinase/Kinlytic) but discontinued after manufacturing and safety concerns; a manufacturer is working toward a US re-entry targeting 2028, not yet approved. It does not appear to be currently marketed in Australia. Its availability in New Zealand could not be confirmed in this research. (3) (4) (1) (2) (5) (6)

Why is urokinase not available in the United States anymore?

Urokinase (originally marketed as Abbokinase, later reformulated as Kinlytic) was withdrawn from the US market after manufacturing and safety concerns, and it has not been commercially available since around 2010-2011. As of 2026, the current rights-holder (Microbix Biosystems) is actively working on manufacturing improvements and a regulatory filing aimed at a 2028 return to the US market for a catheter-clearance use, but it is not yet approved or available. (1) (2)

What is the most important risk with urokinase?

Bleeding. It is the most frequent and most severe effect of urokinase treatment, and rare but serious internal bleeding, including fatal bleeding into the brain, has occurred. This is why urokinase is only given in hospital with close monitoring. (3) (1)

What is the mechanism of action of urokinase?

Urokinase is a serine protease that directly converts plasminogen to plasmin, the enzyme responsible for degrading fibrin clots, without requiring a fibrin-binding cofactor (unlike streptokinase, it is not antigenic in the same way, and unlike alteplase it is not fibrin-selective, which contributes to its systemic fibrinolytic/bleeding-risk profile). (3) (1)

What is the generic name of Urokinase?

The generic name is urokinase. (3) (1)

What class of drug is urokinase?

Urokinase is classed as: Thrombolytic (fibrinolytic) enzyme. (3) (1)

References

  1. KINLYTIC (urokinase for injection), powder, lyophilized, for solution -- DailyMed label recordU.S. Food and Drug Administration / DailyMed (NIH) -- most recent label on file for Kinlytic (urokinase for injection) · United States · accessed 2026-07-30 · source 1
  2. Current (2026) US commercial availability status of Kinlytic/urokinaseMultiple independent secondary sources (Mayo Clinic, Drugs.com) plus live 2026 industry/news reporting on the rights-holder's re-entry program · United States · accessed 2026-07-30 · source 2
  3. Syner-KINASE (urokinase) 250,000 IU powder for solution for injection/infusion -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Syner-Medica Ltd · United Kingdom · accessed 2026-07-30 · source 3
  4. Syner-Kinase (urokinase) -- Article 29(4) referral (2019) and urokinase PSUSA/00003083 nationally authorised products list (March 2025)European Medicines Agency (EMA) -- Article 29(4) referral outcome and PSUSA nationally-authorised-products list · European Union · accessed 2026-07-30 · source 4
  5. KINLYTIC (UROKINASE FOR INJECTION) -- Drug Product Database record (live JSON API)Health Canada Drug Product Database (DPD) API · Canada · accessed 2026-07-30 · source 5
  6. Urokinase -- current Australian market statushealthdirect.gov.au (Australian government consumer health service) plus general search corroboration of TGA/ARTG history · Australia · accessed 2026-07-30 · source 6
  7. No Medsafe record located for urokinase as a registered productN/A -- absence-of-evidence record, not a source · New Zealand · accessed 2026-07-30 · source 7

Brand names by country

Single-ingredient urokinase names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Kinlytic (1) (2)DailyMed marketing status inactive not currently marketed · 250,000 IU lyophilized powder for injection · ImaRx Therapeutics, Inc. (historical); Microbix Biosystems Inc. (current rights-holder pursuing re-entry)

United Kingdom

  • Syner-KINASE (3)MHRA licensed emc smpc confirmed · 10,000 IU, 25,000 IU, 100,000 IU, 250,000 IU, 500,000 IU · Syner-Medica Ltd

Canada

  • Kinlytic (5)Health Canada DPD API cancelled post market DIN 00749702 · historical · Microbix Biosystems Inc
View brands in additional countries.

European Union

Syner-Kinase (4)

This page provides general reference information about urokinase and is not a substitute for advice from the hospital or specialist team managing your treatment. All dosing and treatment decisions should be made with your care team, and actual local availability should always be confirmed directly, since this varies by country.

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