thrombolytic agents Flashcards
alteplase
tissue plasminogen activator (t-PA)
poor enzyme in the absence of fibrin, binds fibrin w/ high affinity, fibrin-bound plasminogen activator
efficient degradation of clot fibrin
rapid hepatic clearance from plasma, requires continuous IV admin
nonantigenic
tenecteplase
tissue plasminogen activator, binds fibrin and converts plasminogen to plasmin
has a longer plasma half life compared to native t-PA
resistant to inhibition by PAI-I
complication of thrombolytic therapy
hemorrhage- lysis of fibrin at sites of vascular injury
systemic lytic state resulting from systemic formation of plasmin, produces fibrinogenolysis, destroys clotting factors ( 5 and 8). minor bleeding at site of injection, major bleeding rare. intracerebral hemorrhage rare
incidence of bleeding is similar between alteplase
incidence of bleeding higher when used w/ thromolytic therapy is combined w/ aspirin or heparin
icidence of hemorrhage is propotional to the dose of the thrombolytic agent used
indications of thrombolytic therapy
management of st elevation myocardial infarction, for the lysis of thrombi in coronary arteries
management of acute ischemic stroke (only alteplase) within 3 hours
management of acute pulmonary embolism (only alteplase)
Contraindictations to thrombolytic therapy
active bleeding, recent surgery within 10 days, GI bleeding within 3 months, recent CVA, known hemorrhagic disorder, known hypersensitivity, sever uncontrolled HTN, pregnancy or postpartum period
aminocaproic acid
inhibitor of fibrinolysis
a synthetic lysin analog that binds to the lysine binding sites of plasminogen and plasmin, blocking the binding of plasmin to fibrin, competitive inhibitor of plasminogen to fibrin
can reverse states associated with an excessive breakdown of fibrin, effective in decreasing hemorrhage with surgical procedures
concentrated in urine useful for treating ut bleeding
