Embolism thrombolytic agents

Streptokinase is a widely employed thrombolytic agent. It is administered to treat a variety of thrombo-embolic disorders, including ... 

Urokinase is also a thrombolytic agent, used for treating pulmonary embolism. Two variants of this protease have already been isolated one of 54 kDa and another of 33 kDa, both displaying proteolytic activity over plasminogen. Until recently, the only exogenous source for this enzyme was urine. However, in 2002 the product called Abbokinase, which is produced in neonatal kidney tissue culture, was approved in the USA. 

Capstick T, Henry M T (2005). Efficacy of thrombolytic agents in the treatment of pulmonary embolism. Euro. Respirat. J. 26(5) 864-874. 

Early application of reperfusion therapy with thrombolytic agents has significantly improved the outcomes of acute myocardial infarction and other conditions, such as pulmonary embolism, DVT, arterial thrombosis, acute thrombosis of retinal vessel, extensive coronary emboli, and peripheral vascular thromboembolism (124). 

Tissue plasminogen activator tPA alteplase (Activase) 59.04 Plasma volume (0.05 Lkg- ) 0.083 (initial) IV bolus injection followed by IV infusion (1.0 in both) Thrombolytic agent used in acute myocardial infarction, acute ischemic stroke and pulmonary embolism... 

The effect of hypothermia in combination with thrombolytics has also been evaluated in only a few experimental studies. Meden et al. (11) studied differences in thrombolytic effectiveness in a rat embolic stroke model. In this study, 2 h of intraischemic hypothermia was administered with or without thrombolytic therapy. Thrombolysis was initiated at 2 h after ischemia onset. The investigators found that both hypothermia and thrombolysis significantly reduced infarct volume, but they could not demonstrate any added benefit of thrombolysis over hypothermia alone. A recent study by Wang et al. (12) used a focal embolic brain ischemia model to study the effects of minocycline, an antiinflammatory agent, alone or in combination with mild hypothermia (34—35°C started 1 h after embolization, 2-h duration). The results showed that both minocycline and the hypothermia-minocycline combination reduced infarct volume significantly, but no additive effect was observed. 

Anticoagulants and thrombolytics, particularly warfarin, can systemically embolize cholesterol particles from aortic atherosclerotic plaques to small arteries and arterioles, including renal arterioles. These agents remove or prevent thrombus formation over ulcerative plaques, causing emboh. Cholesterol emboli induce an inflammatory obliterative vascular response, causing renal ischemia. Purple discoloration of the toes and mottled skin over the legs are important clinical clues. 

Thrombolytics, on the other hand, are drugs needed to dissolve the newly formed thrombi in conditions such as DVT, acute pulmonary embolism, or myocardial infarction. Because of their lack of specificity, however, these agents actually may cause internal bleeding and, thus, are contraindicated with the use of many other therapeutic agents. 

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