View source for Low molecular weight heparin

==Background==
*Class of [[anticoagulant]] medications.
*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 inhibits activated factor X.<ref>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"</ref>
*LMWH therapy is monitored by the anti-factor Xa assay (measures anti-factor Xa activity).
**Cannot be acceptably measured using the partial thromboplastin time (PTT) or activated clotting time (ACT) tests.

==Types==
{| class="wikitable"
|-
! 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.<ref>http://chestjournal.chestpubs.org/content/119/1_suppl/64S.full</ref>
*Possibly a smaller risk of bleeding
*Smaller risk of osteoporosis in long-term use.
*Smaller risk of [[Heparin-Induced Thrombocytopenia (HIT)|heparin-induced thrombocytopenia]], a potential side effect of [[Unfractionated heparin|heparin]].
*The anticoagulant effects of heparin are typically reversible with [[Protamine sulfate|protamine sulfate]], while protamine's effect on LMWH is limited.

==Indications==
*[[Deep venous thrombosis]]
*[[Pulmonary embolism]]
*[[Non ST-Elevation Myocardial Infarction (NSTEMI)]]
*[[ST-segment elevation myocardial infarction (STEMI)]]
*[[Stroke (main)]]

==See Also==
*[[Coagulopathy (main)]]
*[[Unfractionated heparin]]

==References==
<references/>

[[Category:Pharmacology]]
[[Category:Heme/Onc]]