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