<prompt> Direct fibrinolytics areis:R4prourokinaseAlfimiprasertpAAll  <response>: Ans. b Alfimeprase. Ref. Harrisons medicine 16th ed. 690Alfimeprase is a metalloproteinase that degrades fibrin in a plasmin-independent fashion. It is a novel thrombolytic based on snake venom derived protein. It is a direct fibrinolytic. It is not a plasminogen activator. It is neutralized by alpha-macroglobulin.PHARMACOLOGICAL REPERFUSION Therapeutic plasminogen activators include streptokinase, urokinase, tPA and non-tPA fibrinolytics like Recombinant prourokinase, staphylokinase, and alfimeprase.- They are fashioned after endogenous tPA or urokinase that convert plasminogen into active plasmin. Plasmin degrades fibrinogen and fibrin in to FDPs.- tPA is released from endothelial cells, enters the fibrin clot, and activates plasminogen to plasmin.- Any free plasmin is complexed with a,plasmin inhibitor a2PI.- Fibrin is degraded to low-molecular-weight fragments, fibrin degradation products FDPs. Innovative intravenous pharmacological reperfusion strategies include:- Novel fibrinolytic agents tenecteplase, reteplase, desmetolplase, plasmin, and microplasmin,- GP IlbIIIa antagonists platelet disaggregating effects abciximab and tirofiban,- Combination therapies to improve efficacy of clot lysis fibrinolytics and GP IIbIIIa agents, and fibrinolytics and direct thrombin inhibitors, increase the time window for clot lysis fibrinolytics and neuroprotectants, and reduce the frequency of hemorrhagic complications. 