Apixaban Starting Dose for DVT Treatment
For adult patients with normal renal function and acute deep vein thrombosis, start apixaban at 10 mg orally twice daily for the first 7 days, then reduce to 5 mg orally twice daily. 1
Initial Loading Phase (Days 1-7)
The FDA-approved dosing regimen requires a loading dose of 10 mg orally twice daily for exactly 7 days to achieve rapid therapeutic anticoagulation. 1 This higher initial dose is critical and distinguishes apixaban from other direct oral anticoagulants:
- No parenteral anticoagulation is required before starting apixaban, unlike edoxaban which requires 5 days of low molecular weight heparin. 2
- The American College of Cardiology validated this approach in the AMPLIFY trial, demonstrating non-inferiority to conventional enoxaparin/warfarin therapy with significantly lower major bleeding rates (0.6% vs 1.8%). 3, 4
- This loading dose regimen was specifically designed to rapidly suppress coagulation activity in acute DVT patients. 5
Maintenance Phase (After Day 7)
After completing the 7-day loading phase, transition to 5 mg orally twice daily and continue for at least 3 months for provoked DVT. 1
- For unprovoked DVT or patients with ongoing risk factors, the American College of Chest Physicians recommends considering longer treatment duration beyond 3 months. 3, 4
- The 5 mg twice-daily maintenance dose provides effective anticoagulation while minimizing bleeding risk. 6
Critical Dosing Considerations
Do not shorten the 7-day loading phase even if the patient has received initial parenteral anticoagulation, as this increases bleeding risk without improving efficacy. 7 A 2025 study demonstrated that patients who received shortened apixaban lead-in therapy after parenteral anticoagulation had significantly higher bleeding rates (18.5% vs 5.1%, P=0.02) compared to the full 7-day regimen. 7
Renal Function Requirements
- No dose adjustment needed for creatinine clearance ≥15 mL/min. 3
- Avoid apixaban in severe renal impairment (CrCl <15 mL/min) as these patients were excluded from clinical trials. 4, 8
- Use caution with CrCl <25 mL/min. 4
Drug Interactions
For patients taking combined P-glycoprotein and strong CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir), reduce the dose by 50% during both the loading and maintenance phases. 1 This means:
- Loading phase: 5 mg twice daily instead of 10 mg twice daily
- Maintenance phase: 2.5 mg twice daily instead of 5 mg twice daily
Extended Treatment Beyond 6 Months
If extended anticoagulation is required after completing at least 6 months of treatment, reduce to 2.5 mg orally twice daily for long-term secondary prevention. 1 This reduced dose minimizes bleeding risk while maintaining efficacy for preventing recurrent VTE. 8, 9
Special Population: Cancer-Associated DVT
For patients with cancer-associated DVT, apixaban is now upgraded to grade 1A recommendation with the same dosing regimen: 10 mg twice daily for 7 days, then 5 mg twice daily. 2 The 2022 International Initiative on Thrombosis and Cancer guidelines elevated apixaban to the highest recommendation level based on trials demonstrating non-inferiority to low molecular weight heparin with comparable safety profiles. 2
Common Pitfalls to Avoid
- Never skip or shorten the 7-day loading phase - this is a fixed requirement, not a suggestion. 1
- Do not use parenteral anticoagulation bridging when starting apixaban - it increases bleeding risk without benefit. 7
- Do not double doses if a dose is missed; take the next scheduled dose. 1
- Avoid premature discontinuation without transitioning to another anticoagulant, as this significantly increases thrombotic risk. 1