High-dose systemic streptokinase and acylated streptokinase-plasminogen complex (BRL 26921) in acute myocardial infarction: alterations of the fibrinolytic system and clearance of fibrinolytic activity.

We report the results of two consecutive studies using intravenous bolus injections of streptokinase (SK) or acylated plasminogen-SK complex (BRL 26921) in patients with acute myocardial infarction (AMI). In the first study, 20 patients received either 750,000 units (U) SK (group IA, n = 10) or 1,500,000 U SK (group IB, n = 10) within 5-10 min intravenously. In the second study 10 consecutive patients received 750,000 U SK within 15 min (group IIA) intravenously. The following 10 consecutive patients received 30 mg BRL 26921 within 2 min (group IIB). Early reperfusion was found in 16 patients in the first study (8 in each group) and in 18 patients in the second study (9 in each group). The decrease of fibrinolytic activity was biphasic with a half-disappearance time of 112.5 min for BRL 26921 and 31 (IA) and 18 (IB) min for SK. alpha 2-Antiplasmin depletion and a decrease of fibrinogen was observed with no differences after bolus injections of SK and of BRL 26921.