Examples of Low Molecular Weight Heparins (LMWH)
The three primary LMWHs available in the United States are enoxaparin, dalteparin, and tinzaparin. 1, 2, 1
FDA-Approved LMWHs in the United States
The following LMWHs are FDA-approved and commercially available 1, 2, 3:
- Enoxaparin (Lovenox): Approved for both VTE prophylaxis and immediate treatment, as well as acute coronary syndromes 1, 2, 4
- Dalteparin (Fragmin): Approved for VTE prophylaxis and extended treatment of symptomatic VTE in cancer patients 1, 2, 4
- Tinzaparin (Innohep): Currently approved only for immediate VTE treatment 1, 2
Additional LMWHs Available Internationally
Several other LMWHs are available in Europe and Canada but not FDA-approved in the United States 5, 3, 6:
- Nadroparin (Fraxiparin): Used in Europe and Canada for VTE prophylaxis and treatment 5, 3, 6
- Reviparin (Clivarine): Available in select international markets 5, 3
- Certoparin: Used primarily in Europe 6, 7
- Bemiparin: Available in certain European countries 6
- Parnaparin: Used in select international markets 6
Key Pharmacologic Differences
While these LMWHs are often used interchangeably in clinical practice, they are NOT therapeutically equivalent and differ in important ways 1, 2, 1:
- Mean molecular weight: Ranges from approximately 4,500 to 5,000 Da across different preparations 1, 3
- Half-life: Varies between agents, affecting dosing frequency 1, 3
- Anti-Xa to anti-IIa ratio: Differs based on method of depolymerization, affecting their ability to inhibit thrombin versus factor Xa 1, 3
- Method of preparation: Each LMWH is produced through different chemical or enzymatic depolymerization methods (nitrous acid, benzylation, peroxidative, or enzymatic with heparinase) 3, 6
Clinical Implications
Do not assume all LMWHs are interchangeable—they differ in molecular weight, half-life, and FDA-approved indications 8, 9. The choice of LMWH should be based on 1:
- FDA approval for the specific indication
- Presence of renal insufficiency (enoxaparin has specific dosing for severe renal impairment) 1
- Cost and formulary availability 1
- Ease of administration and monitoring requirements 1, 9
For cancer-associated VTE specifically, dalteparin has the highest quality evidence and is the only LMWH FDA-approved for extended treatment in this population 10, 4.