Changes in the plasma fibrinolytic system during urokinase therapy: comparison of tissue culture urokinase with urinary source urokinase in patients with pulmonary embolism

This study compares the biochemical effects of two types of UK, UUK and TCUK, during and after their use in patients with angiographically demonstrated pulmonary embolism. Of the 31 randomized patients who were admitted to the study, 30 completed the course of therapy, 15 in each group. Treatment with either type of UK was administered as a loading dose of 2,000 U/lb followed by an hourly rate of 2,000 U/lb for 12 hr. Blood samples were collected prior to and at 2, 6, 12, and 24 hr and 3 and 5 days after the start of treatment and assayed for WBELT, fibrin plate lysis, radioactive fibrin clot lysis, plasma plasminogen, plasma fibrinogen, and serum fibrin/fibrinogen degradation products. The changes which occur in these biochemical parameters during and after UK infusion have been clearly documented and provide a reference for comparison with new agents and drug regimens. As reflected by changes in these six parameters, the rate, degree, and duration of fibrinolytic effect were strikingly similar in the patients who received UUK and TCUK. The proportion of patients who demonstrated fibrinolytic activity or side effects such as bleeding and temperature elevation was the same as already reported with UUK. The results demonstrated biochemical equivalence and equal safety for the two types of UK when administered at this dose, and it seems reasonable to expect that they are equally effective in altering hemodynamic and clinical parameters of patients with pulmonary embolism.