Uronase

Deep vein thrombosis : Initial loading dose of 4,400 IU/kg in 15 mL soln over 10 min, followed by 4,400 IU/kg/hr IV infusion for 12-24 hr. Pulmonary embolism : Initial loading dose of 4,400 IU/kg in 15 mL soln over 10 min followed by 4,400 IU/kg/hr IV infusion for 12 hr. Peripheral vascular occlusion : Infuse 2,500 IU/mL (500,000 IU in 200 mL) into clot at a rate of 4,000 IU/min for 2 hr. Advance the catheter into the remaining occluded area & infuse at 4,000 IU/min for another 2 hr. This may be repeated up to 4 times. Hyphaema : 5,000 IU in 2 mL saline soln is injected and withdrawn repeatedly over the iris. If residual clot remains, leave 0.3 mL in the anterior chamber for 24-48 hr to facilitate further dissolution. Clotted arterio-venous shunts : Instill 5,000-25,000 IU into affected shunt limb & clamp for 2-4 hr, followed by aspiration of lysate. Repeat if necessary.

Urokinase is used for the treatment of pulmonary embolisms. The low molecular weight form of human urokinase consists of an A chain of 2,000 daltons linked by a sulfhydryl bond to a B chain of 30,400 daltons. Urokinase is an enzyme (protein) produced by the kidney, and found in the urine. There are two forms of urokinase which differ in molecular weight but have similar clinical effects. Urokinase is the low molecular weight form. Urokinase acts on the endogenous fibrinolytic system. It converts plasminogen to the enzyme plasmin. Plasmin degrades fibrin clots as well as fibrinogen and some other plasma proteins. Urokinase acts on the endogenous fibrinolytic system. It cleaves the Arg-Val bond in plasminogen to produce active plasmin. Plasmin degrades fibrin clots as well as fibrinogen and other plasma proteins.

Overt bleeding, haemorrhagic complications, fever, haematuria, initial severe pain & dull ache in shunt limb.

Recent surgery or biopsy, severe HTN, severe hepatic or renal insufficiency. Pregnancy & immediate postpartum period.

GI lesions & in multiple intracardiac or intravascular punctures as a consequence of cardiopulmonary resuscitation.

Concomitant use of oral anticoagulant or heparin & drugs that affect platelet function may increase risk of haemorrhage.