streptokinaasi

Streptokinase is a protein produced by certain strains of beta-hemolytic Streptococcus, most notably Streptococcus pyogenes. It is not an enzyme itself but acts as a plasminogen activator by forming a complex with plasminogen. This complex acquires proteolytic activity and converts additional plasminogen into plasmin, the main enzyme responsible for fibrinolysis. The resulting plasmin degrades fibrin clots, helping to restore blood flow in occluded vessels.

In medicine, streptokinase has been used as a thrombolytic agent for acute myocardial infarction, pulmonary embolism, deep vein thrombosis, and occluded indwelling catheters. Because of its antigenicity, many individuals have preformed antibodies against streptokinase, which can reduce efficacy with subsequent doses. It has largely been superseded in many settings by tissue plasminogen activator (tPA) derivatives, such as alteplase and tenecteplase, which tend to have more favorable safety profiles and reduced immunogenicity. Nevertheless, streptokinase remains in use in some regions and is available in recombinant forms or alternative preparations to address production and supply considerations.

Production and safety considerations: commercial streptokinase is produced by fermentation of streptococcal cultures and is supplied as a solution for intravenous administration. Because of its systemic plasminogen activation, its use carries a bleeding risk. Adverse effects include major bleeding, allergic reactions or fever, and, rarely, anaphylaxis. Contraindications include active internal bleeding, known bleeding disorders, recent major surgery or trauma, recent intracranial hemorrhage, and uncontrolled hypertension.