Low Molecular Weight and Unfactionated Heparins: An Analysis of Prescribing Patterns and Outcomes

Abstract

In many institutions, low molecular weight heparins (LMWHs) are replacing unfractionated heparin in the management of thromboembolism. LMWHs have a number of potential advantages over unfractionated heparin that may offset their higher cost, provided that they are utilized and monitored appropriately. Following the addition of enoxaparin and dalteparin to a teaching hospital formulary, we studied prescribing patterns and outcomes associated with the use of both LMWHs and unfractionated heparin for the prophylaxis or treatment of thromboembolism. The study identified several problem areas, including dalteparin dosing in high-risk patients, dosing for treatment of thromboembolism, timing of prophylactic doses prior to surgery, and inappropriate use of coagulation monitoring tests. This study will provide useful information to hospital pharmacists involved in determining prescribing guidelines and initiating ongoing monitoring programs for patients receiving antithrombotic therapy.