Thrombolytic therapy: differences between streptokinase and urokinase.

From the Department of Medicine, Division of Hematology, The Johns Hopkins University School of Medicine and Hospital, Baltimore, Maryland. Supported in part by Grant HL 01601 from the National Heart, Lung and Blood Institute, contract PH-43-68-1398, and by the Hazel Dell Foundation. Dr. Bell is a Hubert E. and Anne E. Rogers Scholar in Academic Medicine. Evaluation of thrombolytic therapy in patients with angiographically documented pulmonary emboli was recently completed in a large nationwide study.’ Patients entering this study were randomized according to age, sex, severity of the emboli (the amount of clot present in the pulmonary arterial tree as quantified on the pulmonary angiogram), and physiologic status (shock versus no shock) to one of three different treatment regimens. The therapeutic regimens were streptokinase (SK) given intravenously continuously for 24 hours, urokinase given intravenously continuously for 12 hours, and urokinase given intravenously continuously for 24 hours. Streptokinase was administered in a loading dose of 250,000 U over 20 minutes, followed by 100,000 U/hour for 24 hours. Urokinase was given in a loading dose of 2,000 Committee on Thrombolytic Agents (CTA) U/pound body weight during an interval of 20 minutes, followed by 2,000 CTA U/pound/ hour for 12 or 24 hours.