Table 2.
Comparison of unfractionated and low-molecular-weight heparins
| Heparin | Tinzaparin | Dalteparin | Enoxaparin | |
|---|---|---|---|---|
| Prophylaxis VTE | 5000 units subcutaneously twice to three times daily | 3500-4500 units subcutaneously once daily | 5000 units subcutaneously once daily | 30 mg subcutaneously every 12 h |
| Treatment VTE | Intravenously, based on aPTT (2.5-3.5x baseline 60-120 s) | 175 units/kg subcutaneously once daily | 200 units/kg subcutaneously once daily | 1.5 mg/kg subcutaneously once daily or 1 mg/kg twice daily |
| Average molecular weight (daltons) | 15 000 | 6500 | 6000 | 4500 |
| Anti Xa: IIa ratio | 1:1 | 1.9:1 | 2.2:1 | 2.7-4/1:1 |
| Monitoring | aPTT | Anti-Xa heparin level | Anti-Xa heparin level | Anti-Xa heparin level |
| Peak onset | SC: 2-4 h intravenously: immediate | 4-6 h | 4 h | 3 h |
| Plasma half-life | 1.5 h (1-2 h) | 1.4 h | 2-2.3 h | 3.5-4.2 hr |
| Antidote | Protamine | Protamine (88% neutralized) | Protamine (74% neutralized) | Protamine (54% neutralized) |
| Elimination | Hepatic/renal | Hepatic/renal | Renal | Renal |
| Adjust dose for kidney failure | No | No | Yes (CrCl < 10-30 mL/min) | Yes |