Pharmacologic therapy for the management of thrombosis: unfractionated heparin or low-molecular-weight heparin?

Heparin and heparin-derived drugs play a major therapeutic role in thrombotic and cardiovascular disorders. Infusion of unfractionated heparin (UFH) followed by warfarin has traditionally been the standard pharmacologic therapy for treatment of venous thromboembolism (VTE), which includes both deep vein thrombosis and pulmonary embolism, and for initial therapy of non-ST-elevation (NSTE) acute coronary syndrome (ACS). More recently, low-molecular-weight heparins (LMWHs) have been shown to provide at least as good efficacy and safety outcomes as UFH regimens for prevention of these conditions. In addition to good efficacy outcomes with LMWHs compared with UFH, LMWHs have other advantages over UFH, including improved bioavailability, QD administration, more predictable anticoagulant response, lack of the need for monitoring, and suitability for outpatient use, thereby increasing convenience, reducing cost, and improving cost-to-benefit ratios. In carefully screened and managed patients, LMWH offers a cost-effective, convenient, and safe alternative to UFH for thrombosis management. The aim of this article is to summarize efficacy, safety, and pharmacoeconomic considerations when selecting LMWH versus UFH for thrombosis management in VTE and NSTE ACS.