Low molecular weight heparin

Low molecular weight derivative of unfractionated heparin (e.g. enoxaparin, dalteparin, tinzaparin) that prevents coagulation by targeting factor Xa activity rather than antithrombin activity, as in unfractionated heparin. Usually does not require monitoring with PTT (as opposed to unfractionated heparin) and markedly reduces the risk of Heparin-Induced Thrombocytopenia (HIT). Can be monitored with anti-factor Xa assay in certain clinical scenario.