EFFICACY AND SAFETY OF REPEATED BOLUSES OF UROKINASE IN THE TREATMENTEF DEEP VENOUS THROMBOSIS

The only Food and Drug Administration-approved thrombolytic regimen fo r treatment of deep venous thrombosis (DVT) is a 24- to 72-hour contin uous infusion of intravenous streptokinase. This approach to DVT throm bolysis is not entirely satisfactory because of the bleeding complicat ions that may accompany this therapy. In the current study, we treated 27 patients with DVT with a novel dosing regimen of urokinase: 1,000, 000 U administered as a 10 minute bolus, with a total of 3 boluses giv en over approximately 24 hours. Patients were given heparin overnight between bolus urokinase doses. Efficacy was assessed by comparing base line and prehospital discharge vascular imaging studies, which constit uted either venous ultrasound or contrast venography. A vascular-imagi ng panel of physicians, unaware of the sequence of paired studies, fou nd that 14 patients (52%) had clot lysis (6 slight, 6 moderate and 2 m arked), 9 (33%) had no change, and 4 (15%) had more extensive thrombos is after treatment (1 slight, 2 moderate and 1 marked). There were no bleeding complications. At 48 hours after starting urokinase, mean pla sma fibrinogen levels had decreased 61% from baseline, and the mean bl eeding time had increased 26% from baseline (but remained within the n ormal range). Because of the promising efficacy and safety that were f ound in this case series, it is concluded that fur ther testing of bol us urokinase is warranted against anticoagulation alone.