Anatomical Therapeutic Chemical Classification System
Alteplase is a recombinant human tissue-type plasminogen activator, a glycoprotein, which activates plasminogen directly to plasmin. Once bound to fibrin, it is activated, inducing the conversion of plasminogen to plasmin leading to the dissolution of the fibrin clot.
Drotrecogin alfa is a recombinant version of the natural plasma-derived activated Protein C, from which it differs only by unique oligosaccharides in the carbohydrate portion of the molecule. Activated Protein C is a crucial coagulation regulator. Furthermore, Activated Protein C is an important modulator of the systemic response to infection and has antithrombotic and profibrinolytic properties. Drotrecogin alfa has similar properties to those of endogenous human Activated Protein C.
Protein C is a serine protease with potent anticoagulant effects, especially in the presence of its cofactor protein S. Protein C exerts its effect by the inactivation of the activated forms of factors V and VIII which leads to a decrease in thrombin formation. Protein C has also been shown to have profibrinolytic effects.
Reteplase is a recombinant plasminogen activator that catalyzes the cleavage of endogenous plasminogen to generate plasmin. This plasminogenolysis occurs preferentially in the presence of fibrin. Plasmin in turn degrades fibrin, which is the main component of the matrix of thrombi, thereby exerting its thrombolytic action.
Biofactor streptokinase is a highly purified streptokinase derived from β haemolytic streptococci of Lancefield group C. The activation of the endogenous fibrinolytic system is initiated by the formation of a streptokinase-plasminogen complex. This complex possesses activator properties and converts plasminogen into the proteolytic and fibrinolytic active plasmin.
Tenecteplase is a recombinant fibrin-specific plasminogen activator that is derived from native t-PA by modifications at three sites of the protein structure. It binds to the fibrin component of the thrombus (blood clot) and selectively converts thrombus-bound plasminogen to plasmin, which degrades the fibrin matrix of the thrombus. Tenecteplase has a higher fibrin specificity and greater resistance to inactivation by its endogenous inhibitor (PAI-1) compared to native t-PA.
Urokinase is a highly purified form of naturally occurring human urokinase extracted from urine. It is a thrombolytic agent which converts plasminogen into plasmin (fibrinolysin) a proteolytic enzyme that breaks down fibrin as well a fibrinogen and other plasma proteins.