Characteristics of low molecular weight heparins

They are derived from unfractionated heparin by either enzymatic or chemical depolymerisation. Their mean molecular weight is between 4 and 6.5 kDa, with a range of 2 to 8 kDa. The mean number of saccharide units is between 13 and 22.

Low molecular weight heparins do not prolong the activated partial thromboplastin time. They possess higher anti-Xa than antithrombin effect, i.e. reduced anti-IIa activity relative to anti-Xa activity. Activity is measured by anti-Xa assay. The target range for anti-Xa activity in blood samples drawn 4-6 hours after a dose should be between 0.5 and 1.0 unit/ml. Advantages:

Predictable anticoagulant dose-response relationship.

High bioavailability; less non-specific binding to cationic plasma proteins and to cell surfaces as a result of less negative charge density. Longer plasma half-life (greater than 30 minutes).

Therapeutic anticoagulant effect with once or twice daily subcutaneous injections at fixed, weight-adjusted doses. Reduced binding to platelet factor IV (reduced risk of heparin-induced thrombocytopenia). Less interference with the physiological activation of protein C. Reduced binding to osteoclasts (reduced risk of heparin-induced osteoporosis).


More difficult to reverse with protamine. Too small to inactivate IIa well.

Was this article helpful?

0 0
Tips and Tricks For Boosting Your Metabolism

Tips and Tricks For Boosting Your Metabolism

So maybe instead of being a pencil-neck dweeb, youre a bit of a fatty. Well, thats no problem either. Because this bonus will show you exactly how to burn that fat off AS you put on muscle. By boosting your metabolism and working out the way you normally do, you will get rid of all that chub and gain the hard, rippled muscles youve been dreaming of.

Get My Free Ebook

Post a comment