Uronase500000 IU/10 ml

Uronase is a thrombolytic (fibrinolytic) enzyme administered only in a hospital setting under close medical supervision. Its use is classified by strength of evidence as follows:

Established / FDA-approved use

• Acute massive pulmonary embolism (PE): Uronase is indicated for the lysis of acute massive pulmonary emboli and pulmonary emboli accompanied by unstable hemodynamics, in adult patients where the diagnosis has been confirmed by objective means such as pulmonary angiography or lung scanning.

Established adjunct use

• Clearance of occluded central venous access devices (catheter clearance): Uronase is used to restore patency to intravenous catheters and cannulae obstructed by clotted blood, allowing the device to be used again without removal.

Uronase is not used for routine or minor venous thrombosis, and it is not an antibiotic or anti-infective agent. Its use always requires administration by, or under the direct supervision of, medical personnel experienced in thrombolytic therapy, in a facility equipped for continuous clinical and laboratory monitoring.

Each vial of Urokinase for injection contains Urokinase (a purified proteolytic enzyme obtained from cultured human cells) as the active ingredient, supplied as a sterile, lyophilized (freeze-dried) powder for reconstitution into a solution for intravenous infusion. Strength is expressed in International Units (IU) per vial. Excipients (e.g., mannitol, sodium chloride, buffering agents) may vary by manufacturer; refer to the specific product's package insert for the complete excipient list.

Uronase is a naturally occurring proteolytic enzyme (a serine protease) that acts as a direct plasminogen activator. It is produced from cultured human cells and, when given intravenously, works within the bloodstream to break down blood clots. Uronase belongs to the thrombolytic (fibrinolytic) class of medicines, which are used to dissolve dangerous blood clots that can obstruct blood flow in vital vessels.

Because Uronase carries a significant risk of bleeding, it is reserved for serious, clearly diagnosed conditions such as massive pulmonary embolism, and is given only in a hospital under continuous medical supervision.

Uronase belongs to the therapeutic class of Thrombolytic (Fibrinolytic) Agents, specifically the subclass of plasminogen activators.

Urokinase is a direct plasminogen activator. It works by directly converting the inactive proenzyme plasminogen into its active form, plasmin, by cleaving a specific peptide bond in the plasminogen molecule. Unlike some other thrombolytics, Urokinase activates both fibrin-bound and circulating (free) plasminogen.

Plasmin is a non-specific proteolytic enzyme that degrades the fibrin meshwork holding a blood clot (thrombus) together, as well as other plasma proteins such as fibrinogen, and clotting factors V and VIII. This dual action dissolves the clot but also produces a measurable systemic breakdown of clotting factors, which is the basis of Urokinase's bleeding risk.

Following intravenous administration, Urokinase is cleared rapidly from the circulation, primarily by the liver, with a short plasma half-life; its clot-dissolving effect on the fibrinolytic system, however, may persist for several hours after an infusion is stopped.

Uronase is administered only intravenously, by or under the direct supervision of medical personnel experienced in thrombolytic therapy, in a setting equipped for continuous clinical, hemodynamic, and coagulation monitoring.

• For pulmonary embolism, Uronase is given as an initial loading infusion followed by a continuous maintenance infusion using a calibrated constant-infusion pump, through a dedicated line with an in-line 0.22-micron filter.
• For catheter clearance, the reconstituted solution is instilled directly into the occluded catheter lumen rather than infused systemically.
• Vital signs, puncture sites, and signs of bleeding must be monitored closely throughout and after administration.

Uronase must never be administered intramuscularly, and invasive procedures, arterial punctures, and intramuscular injections should be minimized during and shortly after treatment because of bleeding risk.

Only well-established, clinically significant interactions are listed. Because Uronase works by promoting clot breakdown, its main interactions involve an additive increase in bleeding risk:

• Anticoagulants (e.g., heparin, warfarin, direct oral anticoagulants): concurrent use substantially increases the risk of serious or fatal hemorrhage; these are typically withheld during Uronase infusion and coagulation status is checked before resuming.
• Antiplatelet agents (e.g., aspirin, clopidogrel, NSAIDs): increase bleeding risk when combined with Uronase and are used with caution during and shortly after treatment.
• Other drugs affecting hemostasis (e.g., other thrombolytics): combining Uronase with another thrombolytic agent is avoided due to compounded bleeding risk.

Before giving Uronase, the treating physician reviews all current medications, including recent anticoagulant or antiplatelet use.

The most important and frequent adverse reaction associated with Uronase is bleeding, which can range from minor (e.g., oozing at puncture sites, bruising) to severe or fatal (e.g., intracranial hemorrhage, gastrointestinal or retroperitoneal bleeding). Other reported adverse effects include:

• Hypersensitivity/allergic reactions (rash, itching, flushing, bronchospasm; rarely anaphylaxis).
• Infusion-related reactions such as fever, chills, or transient hypoxia.
• Reperfusion arrhythmias as a blocked vessel reopens (see Precautions).
• Hypotension during infusion.
• Nausea.

Patients should seek immediate medical attention for unusual bruising, bleeding that does not stop, severe headache, sudden weakness, confusion, or difficulty breathing during or after treatment.

Pregnancy: Thrombolytic agents such as Uronase carry a significant risk of maternal and fetal bleeding, including placental abruption and fetal loss. Uronase should be used in pregnancy only in life-threatening situations (such as massive pulmonary embolism) where the potential benefit to the mother clearly justifies the potential risk to the fetus, and only under specialist supervision in a hospital setting. It should not be used electively or for non-life-threatening indications during pregnancy. A physician must always be consulted before use in a pregnant patient.

Lactation: There is limited data on whether Uronase passes into human breast milk. Because Uronase is used only in acute, hospital-based, life-threatening situations, breastfeeding decisions are made individually with the treating physician, weighing the mother's clinical urgency against infant exposure.

Bleeding risk: Bleeding is the major risk of Uronase therapy and is the reason careful patient selection is essential. Bleeding can range from minor oozing at injection or puncture sites to severe or fatal intracranial hemorrhage. Patients must be monitored closely for signs of bleeding throughout and after infusion, and personnel and supplies for managing bleeding complications (including blood products) must be readily available.

Specialist administration required: Uronase must be administered only by, or under the direct supervision of, medical personnel experienced in thrombolytic therapy, in a facility with appropriate laboratory and clinical monitoring capability.

Hypersensitivity: Allergic and hypersensitivity reactions, including rare anaphylaxis, may occur; patients should be observed for signs of allergic reaction during administration.

Reperfusion arrhythmias: When treating pulmonary embolism or clearing a vascular occlusion, restoration of blood flow may be accompanied by reperfusion arrhythmias; cardiac monitoring is advised during treatment.

Invasive procedures: Arterial and venous punctures, intramuscular injections, and other invasive procedures should be minimized during and shortly after Uronase therapy because of bleeding risk at puncture sites.

Uronase is not an antibiotic and carries no antimicrobial stewardship considerations; it must be given strictly as directed by the treating physician in a hospital setting, never self-administered or adjusted without medical supervision.

Overdose or excessive dosing of Uronase primarily manifests as bleeding, which can be severe. There is no specific antidote. If overdose or excessive bleeding is suspected, the Uronase infusion should be stopped immediately and the patient should seek or be given immediate emergency medical attention. Management is supportive and may include volume replacement, transfusion of blood products (e.g., packed red cells, fresh frozen plasma, cryoprecipitate), and, in life-threatening bleeding, antifibrinolytic agents, all under close hospital supervision. Do not attempt any home management of a suspected Uronase overdose; contact emergency services or poison control immediately.

Store intact, unreconstituted vials of Uronase under refrigeration at 2°C to 8°C (36°F to 46°F), protected from light. Do not freeze. Once reconstituted, use promptly per the product's specific instructions and do not shake the solution (to avoid foaming/loss of activity). Keep out of reach of children. Any unused reconstituted solution should be discarded as directed by hospital protocol.

Renal impairment: No well-established dose adjustment is defined for renal impairment; Uronase is used with caution and close monitoring in patients with significant renal disease, as reduced clearance of the fibrinolytic effect may theoretically increase bleeding risk.

Hepatic impairment: Uronase is used with caution in patients with significant liver disease, since Uronase is cleared hepatically and hepatic synthesis of clotting factors may already be impaired, increasing bleeding risk.

Elderly patients: Older patients, particularly those over 75 years, may be at increased risk of intracranial hemorrhage with thrombolytic therapy; careful risk–benefit assessment is required.

Recent surgery or trauma: Patients with recent major surgery, organ biopsy, or trauma (other than the qualifying absolute contraindications) require careful individualized risk assessment before Uronase is given.

Duration of Uronase therapy is short and indication-specific, and is always determined by the treating physician:

• Massive pulmonary embolism: typically a loading infusion over about 10 minutes followed by a continuous infusion for approximately 12 hours, with treatment duration and continuation guided by the patient's clinical and coagulation status.
• Catheter clearance: a single instillation with a dwell time of about 30–60 minutes, occasionally repeated once if the catheter remains blocked.

Uronase is not intended for prolonged or repeated courses outside of these acute, medically supervised settings.

Uronase is supplied as a sterile lyophilized (freeze-dried) powder that must be reconstituted before use. General principles (always follow the specific product's package insert):

• Reconstitute using the diluent specified by the manufacturer (commonly sterile water for injection, without preservatives), added slowly down the side of the vial.
• Do not shake the vial; gently roll or swirl it to dissolve, as shaking can denature the enzyme and reduce potency (may cause foaming).
• Inspect the reconstituted solution; it should be a clear, colorless to slightly straw-colored solution, free of visible particulate matter. Discard if discoloration or particulates are seen.
• Further dilute as directed for intravenous infusion, or use directly for catheter instillation, per protocol.
• Use the reconstituted solution promptly; do not store reconstituted solution for extended periods, and discard any unused portion as directed by hospital policy.

Urokinase is classified under: Thrombolytics; Fibrinolytic enzymes; Plasminogen activators (direct-acting, non-fibrin-selective).

Urokinase is a serine protease enzyme that acts as a direct activator of the fibrinolytic system. It directly cleaves the Arg560–Val561 peptide bond of the zymogen plasminogen, converting it into the active enzyme plasmin. Urokinase activates both circulating (free) plasminogen and plasminogen bound within a fibrin clot, distinguishing it from fibrin-selective thrombolytics.

Once formed, plasmin degrades the fibrin strands that form the structural matrix of a blood clot, dissolving the thrombus and restoring blood flow through the previously occluded vessel or catheter. Plasmin also proteolyzes circulating fibrinogen and clotting factors V and VIII, producing a systemic "lytic state" that underlies the drug's principal risk of bleeding.

B

The safety and efficacy of Uronase for systemic thrombolysis (e.g., in pulmonary embolism) have not been established in pediatric patients through adequate and well-controlled studies. Uronase is used off-label in some children, most often for restoring patency of occluded central venous catheters, under the supervision of a pediatric specialist experienced in thrombolytic therapy, using weight-adjusted dosing per institutional protocol. Use in neonates and infants requires particular caution given their limited data and higher bleeding vulnerability. Any pediatric use of Uronase must be individualized and physician-directed.