Urokinase is an injected drug administered by physicians to dissolve blood clots and treat deep-vein thrombosis, but is also used for unblocking central venous catheters as well as arteriovenous hemodialysis shunts that have become blocked and are no longer efficient for transporting fluids.


What is Urokinase?

Naturally occurring in the body, Urokinase is an enzyme that produces active plasmin, which is a substance that degrades the fibrin in blood clots as well as other plasma proteins. Working to disrupt the clotting cycle, Urokinase breaks down blood clots as if on target. The man-made drug product has been developed to mimic the enzyme already produced by the body, enabling health care professionals to administer this drug when and where it will be most effective.

Urokinase is sometimes referred to as a clot-busting drug and acts to help the body dissolve unwanted blood clots by producing a substance called plasmin, which attacks the fibrin in the clot itself. Urokinase is injected into a vein through an IV by a physician or nurse. Monitoring of all vital signs after administering Urokinase is mandatory, as is prevention of future blood clots. Other clot-busting drugs include Tenecteplase, Alteplase, Reteplase and Streptokinase, to name a few.

Patients who are in an emergency situation and experiencing pulmonary embolism are typical candidates for Urokinase. Heart bypass patients may also be given Urokinase to relieve blocked grafts after their procedure. Heart attack victims may also be administered Urokinase as part of the emergency drug therapy upon reaching the hospital.

Urokinase is also used in intravenous lines and catheters to keep them free of clots and obstruction, especially in dialysis patients. This provides good blood flow and a more efficient dialysis process, which is affected by the speed in and out of the line. The quality of the dialysis process is directly affected by the catheter, so clots in the line are unacceptable.

Patients being treated for blood clots in the lungs or deep veins receive an injection of Urokinase in the arm during a period of several hours and up to 3 days to dissolve the clot. Progress of the dissolving clot is monitored via x-ray and other imaging. Post therapy involves blood thinners to prevent future clots.

Those with blocked intravascular catheters, such as those installed for hemodialysis, will have Urokinase injected directly into the catheter itself and left to work for an hour or so before attempting any procedure. This may be repeated several times until the catheter is unblocked. In some cases, a higher dose of Urokinase into the dialysis line is required if the line is still blocked or slow.

Patients who have had recent surgery, dental extraction, trauma, coma, and history of cerebrovascular disease, aneurysm, pancreatitis and other vascular conditions may not be candidates for receiving Urokinase. In these cases, other forms of blood clot therapy may be required.

Conditions treated

  • Deep-vein thrombosis
  • pulmonary embolism
  • occlusive peripheral arterial disease
  • occluded central venous catheters
  • occluded arteriovenous hemodialysis shunts

Type of medicine

  • Thrombolytic agent

Side Effects

As Urokinase directly affects blood and its clotting abilities, side effects most frequently involve blood-related issues such as:

  • Nosebleeds
  • Easy bruising or bleeding
  • Coughing blood
  • Bleeding gums
  • Bleeding from cuts
  • Dizziness, headache
  • Increased menstrual flow
  • Vaginal bleeding
  • Paralysis
  • Red or dark brown urine or tarry stools
  • Shortness of breath
  • Swelling, weight gain
  • Discoloration of fingers or toes
  • High blood pressure
  • Chest pain, shortness of breath
  • Anxiety or confusion
  • Severe stomach pain

Rarely, Urokinase can also possibly cause allergic reactions that demonstrate side effects such as:

  • Irregular heartbeat
  • Hives, welts or itchy skin
  • Labored breathing
  • Swollen eyes, lips or tongue
  • Chest construction
  • Skin rash
  • Weakness
  • Fatigue
  • Blue lips or fingernails
  • Blurred vision
  • Convulsions

The most common and most severe side effects of Urokinase involve hemorrhage to a puncture or wound during trauma. Care should be taken to avoid activities that may increase the risk of injury during and after administration of Urokinase.


As with any IV administered drug, a health care professional determines the dosage depending on the unique patient situation and vital statistics. In general, the initial adult dose for a pulmonary embolism is 4400 units/kg IV at a rate of 90 mL/hr over 10 minutes. Maintenance doses are the same size at a rate of 15 mL for 12 hours.

Patients with deep vein thrombosis receive the same dosage as pulmonary embolism patients. Other patients with other conditions have their dosage of Urokinase determined by the attending physician.

To unblock catheters and shunts, adults receive injections directly into the occluded catheter of a concentration of 500 units per mL dissolved in a solution of sodium chloride of 0.9%. The catheter lumen is filled and a waiting period of 20 to 60 minutes is observed before the catheter is aspirated. This procedure is repeated as necessary to clear the line.


The list of known drugs that interact with Urokinase is long and varied and includes more than 200 drugs, including:

  • Aspirin
  • Aldactone
  • Bayer Aspirin
  • Bumex
  • CellCept
  • Colace
  • Dilantin
  • Dilaudid
  • Ibuprofen
  • Kayexalate
  • KCI (potassium chloride)
  • Kytril
  • Lipitor
  • Lotension
  • NPH Insulin
  • Percocet
  • Percodan
  • Plavix
  • Prozac
  • Solu-Cortef (hydrocortisone)

Great care should be taken when administering Urokinase to discover all drugs the patient is taking, both prescription and non-prescription as well as herbal and holistic remedies. In general, blood thinners, NSAIDs, pain relievers and blood clot medications will interact with Urokinase.


This drug can cause serious bleeding even after administration is finished. Patients should be monitored for any wounds or any bleeding in urine or in bowel movements. Urokinase is to be administered only by a physician or trained health care professional. If possible, alert your health care professional if you are using blood thinners, aspirin, NSAIDS or any blood clot preventive medicine such as Plavix.

If you have a brain tumor, brain aneurysm, hemophilia or other blood disorder, such as high blood pressure, inform your doctor before receiving Urokinase treatment, if possible. If you have recently had a stroke or surgery on your brain or spinal column or any emergency medical situation that required CPR, you must also inform the doctor administering Urokinase.

Urokinase should only be used in pregnant or breastfeeding women if absolutely necessary in an emergency situation. Urokinase can lead to the premature separation of the placenta if used in the first eighteen weeks of pregnancy. It can also increase the risk of maternal hemorrhage during any stage of pregnancy as well as post-partum. Fetal hemorrhage is also a risk at any time during pregnancy when Urokinase is administered.

Patients who have a history of stroke, kidney disease, diabetes, eye conditions, bacterial endocarditis, blood clots, stomach or intestinal bleeding or are pregnant or recently delivered a baby should notify their doctors of these conditions prior to receiving Urokinase.

Activities that may increase the risk of injury or bleeding should be avoided. Take extra care when shaving or brushing teeth to prevent bleeding. All safety information about Urokinase should be reviewed when receiving this drug for treatment.


Urokinase must be stored out of sight and reach of children and always in the original packaging. Care must be taken to protect the drug from light and temperatures over 77 degrees Fahrenheit (25 degrees Celsius). Do not use this drug if the expiration date has passed.


Urokinase is an enzyme typically found in the urine. In drug form, it is an injection that is administered specifically to dissolve blood clots in the lungs or deep tissues of the body. Injected into a vein via an IV, Urokinase goes to work by dissolving the fibers that make up the clot. This occurs during a period of days, during which the patient is monitored for progress and any side effects.

Also useful in patients with shunts or catheters installed, Urokinase is used to keep these lines clear so that life-saving procedures can commence. In this usage, Urokinase is diluted with a solution and left to work in the catheter itself for a few hours. After this waiting period, the catheter is flushed and it is determined by the health care professional if another administration of Urokinase is required.

Side effects and warnings pertaining to Urokinase include excessive bleeding and dangerous allergic reactions. Adverse reactions with many different drugs, specifically those that affect blood clotting, blood pressure or other vascular conditions, can be experienced by patients who are under treatment with Urokinase. As with any drug, progress and side effects should be closely monitored.

Urokinase is only administered by health care professionals in a hospital or professional setting. Use during pregnancy or breastfeeding should only occur in emergency situations.

Last Reviewed:
December 23, 2017
Last Updated:
December 22, 2017
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