Direct fibrinolytics are/is:

Ans. b (Alfimeprase). (Ref. Harrison's medicine 16th ed. 690)Alfimeprase 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 Ilb/IIIa antagonists = platelet disaggregating effects (abciximab and tirofiban),- Combination therapies to improve efficacy of clot lysis (fibrinolytics and GP IIb/IIIa agents, and fibrinolytics and direct thrombin inhibitors), increase the time window for clot lysis (fibrinolytics and neuroprotectants), and reduce the frequency of hemorrhagic complications.