Review article: Low-molecular-weight heparin as an alternative anticoagulant to unfractionated heparin for routine outpatient haemodialysis treatments.

Unfractionated heparin is currently the most widely used anticoagulant for outpatient haemodialysis. However, unfractionated heparin is a series of molecules, and as such has variable pharmacodynamics. Low-molecular-weight heparins were developed to improve both drug pharmacokinetic and dynamics, so to provide a reliable predictable clinical effect. The low-molecular-weight heparins are potent agents, but have an increased half-life compared with unfractionated heparin, and also require specialist laboratory monitoring. Despite these apparent drawbacks, low-molecular-weight heparins have become the anticoagulants of choice in Western Europe for routine outpatient haemodialysis sessions, due to the reliability of their clinical effect, and ease of administration, coupled with cost reduction. In standard clinical practice laboratory monitoring is not routinely performed, with drug dosing assessed by clinical inspection of the extracorporeal circuit, and the time for fistula needle sites to stop bleeding.