Low molecular weight heparin: Difference between revisions

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==Differences from unfractionated heparin==
==Clinical Differences from [[Unfractionated heparin]]==
Differences from heparin (i.e. "unfractionated [[heparin]]") include:
* Less frequent subcutaneous dosing
* Average molecular weight: heparin is about 15 kDa and LMWH is about 4.5 kDa.<ref>Michael D Randall; Karen E Neil (2004). Disease management. 2nd ed. London: Pharmaceutical Press. 186.</ref>
* Less frequent subcutaneous dosing than for heparin for postoperative [[prophylaxis]] of venous [[thromboembolism]].
* Once or twice daily subcutaneous injection for treatment of venous thromboembolism and in unstable angina instead of intravenous infusion of high dose heparin.
* Once or twice daily subcutaneous injection for treatment of venous thromboembolism and in unstable angina instead of intravenous infusion of high dose heparin.
* No need for monitoring of the [[APTT]] coagulation parameter as required for high dose heparin.<ref>http://chestjournal.chestpubs.org/content/119/1_suppl/64S.full</ref>
* No need for monitoring of the [[APTT]] coagulation parameter as required for high dose heparin.<ref>http://chestjournal.chestpubs.org/content/119/1_suppl/64S.full</ref>
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* Smaller risk of [[heparin-induced thrombocytopenia]], a potential side effect of [[heparin]].
* Smaller risk of [[heparin-induced thrombocytopenia]], a potential side effect of [[heparin]].
* The anticoagulant effects of heparin are typically reversible with [[protamine sulfate]], while protamine's effect on LMWH is limited.
* The anticoagulant effects of heparin are typically reversible with [[protamine sulfate]], while protamine's effect on LMWH is limited.
* Has less of an effect on [[thrombin]] compared to heparin, but about the same effect on Factor Xa.


==Indications==
==Indications==

Revision as of 14:32, 17 March 2015

Background

A class of anticoagulant medications. These drugs are used for treating deep vein thrombosis, pulmonary embolism when it is located in the veins, or heart attacks and strokes when located in the arteries. LMWHs cannot be acceptably measured using the partial thromboplastin time (PTT) or activated clotting time (ACT) tests. Rather, LMWH therapy is monitored by the anti-factor Xa assay, measuring anti-factor Xa activity.

LMWHs are defined as heparin salts having an average molecular weight of less than 8000 Dalton. LMWHs inhibit the coagulation process through binding to antithrombin which in turn inhibition activated factor X.[1]

Types

LMWH Average molecular weight Ratio anti-Xa/anti-IIa activity
Bemiparin 3600 8.0
Nadroparin 4300 3.3
Reviparin 4400 4.2
Enoxaparin (Lovenox) 4500 3.9
Parnaparin 5000 2.3
Certoparin 5400 2.4
Dalteparin 5000 2.5
Tinzaparin 6500 1.6

Clinical Differences from Unfractionated heparin

  • Less frequent subcutaneous dosing
  • Once or twice daily subcutaneous injection for treatment of venous thromboembolism and in unstable angina instead of intravenous infusion of high dose heparin.
  • No need for monitoring of the APTT coagulation parameter as required for high dose heparin.[2]
  • Possibly a smaller risk of bleeding.
  • Smaller risk of osteoporosis in long-term use.
  • Smaller risk of heparin-induced thrombocytopenia, a potential side effect of heparin.
  • The anticoagulant effects of heparin are typically reversible with protamine sulfate, while protamine's effect on LMWH is limited.

Indications

See Also

Source

  1. Garcia DA, Baglin TP, Weitz JI, et al. (2012). "Parenteral anticoagulants: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines"
  2. http://chestjournal.chestpubs.org/content/119/1_suppl/64S.full