Overview of low molecular weight heparin

Low molecular weight heparin (LMWH) (eg enoxaparin, dalteparin) has a more predictable anticoagulant effect and a longer half-life than unfractionated heparin (UFH). LMWH is given parenterally once or twice daily, often without the need for anticoagulation monitoring. LMWH can be used safely during pregnancy and breastfeeding.

LMWH is significantly excreted via the kidneys and can accumulate in patients with kidney impairment; this can lead to overanticoagulation. Heparin-induced thrombocytopenia (HIT) is an uncommon but dangerous complication of LMWH therapy, with an incidence of 0.2% in surgical patientsMartel, 2005. Do not give LMWH to patients with a history of HIT; for alternative anticoagulant therapy, see Treatment of heparin-induced thrombocytopenia.