Pretreatment with heparin in thrombolytic therapy with Urokinase. Heparin-urokinase therapy.

Initially, we administered urokinase to five patients according to the following schedule: 500,000 CTA U during the first 10 min, then 250,000 CTA U/h for 12 h. Using this modality, we noted the appearance, during the first hours of treatment, of hypercoagulability. We then choose to modify the schedule by pretreatment with 7,500 U. i.v. of heparin, followed promptly by 250,000 CTA U/h of urokinase (without a loading dose). This obviate the appearance of hypercoagulability without reducing the fibrinolytic effect of treatment and without producing hemorrhagic complications.