Streptokinase (STK) is a medication used to dissolve blood clots (thrombolysis) in human body. Streptokinase is used mainly treat heart attacks (Myocardia Infarction). There are 2 main types of heart attacks; STEMI and non-STEMI and Streptokinase is only used in STEMI type heart attacks after confirming with an ECG. It is given as an injection into a vein.