The safety and effectiveness of a standard dosage schedule of streptokinase was evaluated in 50 patients with thromboembolic disease. A streptokinase resistance test was performed, and each patient was then treated with 250,000 units of streptokinase infused over 30 minutes followed by 100,000 units per hour. The results of serial tests of fibrinolytic activity were then correlated with the streptokinase resistance in each patient. Forty six of the fifty patients had a resistance of 250,000 units or lower and all these developed an active thrombolytic state with rapid plasminogen depletion. The four patients with a streptokinase resistance in excess of 250,000 units showed a delayed fibrinolytic response; however, once obtained, the fibrinolytic effects were similar to those found in the other 46 patients.
It is concluded that an active thrombolytic state would be obtained most consistently if the inducing dose of streptokinase is individualized for each patient. The thrombolytic effects of a standard dose schedule are less predictable, but its routine use may be an acceptable alternative in a particular community if the range and distribution of the streptokinase resistance have been determined and have been shown to be relatively low in a large percentage of the community.