For patients with non-ST-segment elevation acute coronary syndrome (NSTE ACS) presenting to the emergency department, appropriate anti-thrombotic and anti-platelet therapy is critical to optimize outcome. Unfractionated heparin is often given as an anti-thrombin in this setting, however, if suffers from a number of pharmacologic limitations including non-specific binding, the requirement for frequent monitoring of its anti-coagulant effect, and the formation of antibodies to the heparin/platelet factor 4/platelet complex which can cause heparin-induced thrombocytopenia (HIT) or heparin-induced thrombocytopenia thrombosis syndrome (HITTS). Low molecular weight heparins, also an indirect thrombin inhibitor, can be used without monitoring their anti-thrombin effects. Ease of use and effectiveness makes them a popular choice in the emergency setting.