A fibrinolytic enzyme obtained from the culture of streptococcus strains. Administered intravenously to treat acute myocardial infarction, pulmonary embolism and deep-vein thrombosis. It is also used topically with streptokinase to remove clots or purulent matter from wounds or cavities (pleura, bladder). There is no scientific support for the effectiveness of its oral administration, since there is evidence of its lack of oral absorption and absence of fibrinolytic properties when taken orally (Oliven 1981, Vonmoos 1979). Since the last update we have not found published data on its excretion in breast milk, but given the lack of absorption when taken orally, high molecular weight and very rapid elimination when administered intravenously, it is unlikely to be excreted in breast milk in significant quantities which furthermore would not be absorbed in the infant's intestine.