Ipsilon (ε-amino-caproic acid) has been reported to have the ability to inhibit completely at a small concentration the activity of plasmin.3 The measurement of antiplasmin power in that investigation was studied by using fibrin clots.
The capacity of Ipsilon to inhibit a lytic system in the blood stream may have considerable promise in clinical medicine. The drug may provide a means of producing coagulation of the blood in patients whose clots undergo spontaneous lysis. Ipsilon might also serve as an antidote in patients who have had a lytic system established by streptokinase for the treatment of thrombosis. A conceivable extension of the use of streptokinase would be to produce an incoagulable blood in patients undergoing cardiac surgery when the heart-lung machine is used with the lytic system reversed by Ipsilon. The many clinical uses to which the drug could be put, particularly to inhibit the effects produced by streptokinase
MILLER JM, ROBINSON DR, JACKSON DA, COLLIER CS. Reversal by Ipsilon of Lytic System in Blood Stream Produced in Rabbits by Streptokinase. AMA Arch Surg. 1959;78(1):33-36. doi:10.1001/archsurg.1959.04320010037006