Initial Anticoagulation Dosing for Deep Vein Thrombosis Treatment
For the initial treatment of deep vein thrombosis (DVT), low-molecular-weight heparin (LMWH), fondaparinux, or unfractionated heparin (UFH) should be used with specific recommended dosing regimens. The choice depends on patient characteristics, clinical setting, and availability.
Low-Molecular-Weight Heparin (First-Line Option)
LMWH is generally preferred over other options due to its efficacy, safety profile, and convenience:
- Enoxaparin: 1 mg/kg subcutaneously twice daily or 1.5 mg/kg once daily 1, 2
- Dalteparin: 200 IU/kg subcutaneously once daily 1, 2
- Tinzaparin: 175 anti-Xa IU/kg subcutaneously once daily 1, 2
Fondaparinux (Alternative Option)
- For patients weighing <50 kg: 5 mg subcutaneously once daily 1
- For patients weighing 50-100 kg: 7.5 mg subcutaneously once daily 1
- For patients weighing >100 kg: 10 mg subcutaneously once daily 1
Unfractionated Heparin (Alternative Option)
- Initial intravenous bolus of 80 U/kg followed by continuous infusion at 18 U/kg/hour 1
- Adjust dose to maintain aPTT corresponding to plasma heparin levels of 0.3-0.7 IU/mL anti-factor Xa activity 1
- Continue for 5-7 days 1
Direct Oral Anticoagulants (DOACs)
For initial treatment, specific DOACs can be used with the following dosing:
- Rivaroxaban: 15 mg orally twice daily with food for the first 21 days, followed by 20 mg once daily with food 1, 3
- Apixaban: 10 mg orally twice daily for the first 7 days, followed by 5 mg twice daily 1, 2
- Edoxaban: Requires 5 days of parenteral anticoagulation before initiating 60 mg daily 1
Special Patient Populations
Cancer Patients
- Oral factor Xa inhibitors (apixaban, edoxaban, rivaroxaban) are recommended over LMWH 1, 2
- If using LMWH: dalteparin 200 IU/kg once daily for the first month, then 150 IU/kg once daily 1
Renal Impairment
- For patients with creatinine clearance <30 mL/min, unfractionated heparin is preferred due to its hepatic elimination 2
- Avoid fondaparinux and use caution with LMWH in severe renal impairment 1
Treatment Setting
- Outpatient treatment with LMWH or fondaparinux is appropriate for selected patients without significant comorbidities 1
- Hospitalization should be considered for patients with extensive iliofemoral DVT, significant comorbidities, or high bleeding risk 2
Duration of Initial Treatment
- Parenteral anticoagulation should be continued for a minimum of 5 days and until the INR is ≥2.0 for at least 24 hours when transitioning to vitamin K antagonists 1
- For DOACs, follow the specific initial treatment regimen (e.g., 21 days for rivaroxaban, 7 days for apixaban) 1
Monitoring
- Routine anti-factor Xa monitoring is not necessary with LMWH in most patients 1, 2
- UFH requires aPTT monitoring to adjust dosing 1
- DOACs do not require routine coagulation monitoring 2