Anistreplase: a novel thrombolytic agent for acute myocardial infarction.

Anistreplase, a modified congener of streptokinase, is a recently approved thrombolytic agent used in the treatment of acute myocardial infarction (AMI). Clinical studies have demonstrated anistreplase to be equally efficacious as intracoronary streptokinase when given within four hours of the onset of chest pain. Thirty units, given as a single bolus intravenous injection, result in reperfusion rates of approximately 60-70 percent. The adverse-effect profile of anistreplase compares favorably with that of streptokinase, with hemorrhagic complications being the most serious. Anistreplase has two distinct advantages over both streptokinase and alteplase: (1) it can be administered as a single bolus intravenous injection and (2) it has a longer half-life which may result in decreased reocclusion rates. Anistreplase therapy is associated with reductions in both short- and long-term mortality and has been shown to preserve left ventricular function. A large, long-term, comparative clinical trial (Third International Study of Infarct Survival or ISIS-III) investigating morbidity and mortality rates with streptokinase, alteplase, and anistreplase is ongoing, as is a direct comparative study against alteplase alone (TEAM-3, Multicenter Thrombolytic Trials of Eminase in Acute Myocardial Infarction).