Low MolecularWeight Heparin

Low-molecular-weight fragments produced by chemical depolymerization and extraction of standard heparin consist of heterogeneous polysaccharide chains of molecular weight 2,000 to 9,000. The LMWH molecules contain the pentasaccharide sequence necessary for binding to antithrombin III but not the 18-saccharide sequence needed for binding to thrombin. Compared to standard heparin, LMWH has a 2- to 4-fold greater antifactor Xa activity than antithrombin activity.

LMWH has greater bioavailability than standard heparin, a longer-lasting effect, and dose-independent clearance pharmacokinetics. The predictable relationship between anticoagulant response and dose allows anticoagulant control without laboratory tests. LMWH is more effective than standard heparin in preventing and treating venous thromboembolism. The incidence of thrombocytopenia after administration of LMWH is lower than with standard heparin. Adverse drug reactions like those caused by standard heparin have been seen during therapy with LMWH, and overdose is treated with protamine.

LMWH is available for subcutaneous administration as enoxaparin (Lovenox), dalteparin (Fragmin), ardeparin (Normiflo), and tinzaparin (Innohep). Dana-par oid (Orgaran), a heparinoid composed of heparin sulfate, dermatan sulfate, and chondroitin sulfate, has greater factor Xa specificity than LMWH. Bleeding due to danaparoid is not reversed by protamine.

The Prevention and Treatment of Headaches

The Prevention and Treatment of Headaches

Are Constant Headaches Making Your Life Stressful? Discover Proven Methods For Eliminating Even The Most Powerful Of Headaches, It’s Easier Than You Think… Stop Chronic Migraine Pain and Tension Headaches From Destroying Your Life… Proven steps anyone can take to overcome even the worst chronic head pain…

Get My Free Audio Book


Post a comment