Enoxaparin has recently been shown to be superior to unfractionated heparin in patients with unstable angina/non-ST-elevation myocardial infarction. Theoretical advantages of low-molecular-weight heparin versus unfractionated heparin include a higher ratio of anti-Xa to anti-IIa activity (3:1 for enoxaparin), a more predictable dose response that precludes the need for frequent monitoring, and the convenience of subcutaneous administration