**10. Thrombolytic agents**

Activase (TPA) (Genenetech, South San Francisco, CA) and Tenecteplase (TNK) (Genenetech, South San Francisco, CA) are the most common thrombolytic agents currently available. These drugs are fibrinolytic agents which break down fibrin into split products thus allowing clot to lyse within the vascular system. In the veins, both work similarly but TNK seems to lyse clot faster with less bleeding complications due to its exquisite fibrin specificity. Tenecteplase is the newer of the two agents. It has a 14 fold higher fibrin binding specificity than TPA. Due to the larger volume of clot within veins, a larger dose of drug is necessary to lyse the clot burden. This is one of the reasons for combining mechanical with thrombolytic agents. With combination therapy, less drug can be used in these larger capacitance vessels if combined with one of the above-mentioned mechanical devices.
