Duration of Apixaban in Central Venous Thrombosis
For central venous thrombosis treated with apixaban, treat for a minimum of 3 months if provoked by a transient risk factor, or consider indefinite anticoagulation if unprovoked or associated with persistent risk factors, with dose reduction to 2.5 mg twice daily after 6 months for extended therapy. 1
Initial Treatment Phase
- Start apixaban at 10 mg orally twice daily for 7 days as the loading dose regimen, which requires no initial parenteral anticoagulation 2, 3
- This loading dose demonstrated non-inferiority to conventional enoxaparin/warfarin therapy with significantly lower bleeding rates (0.6% vs 1.8% major bleeding) in the AMPLIFY trial 2
Maintenance Phase (Standard Dose)
- Continue 5 mg orally twice daily after the initial 7 days for the remainder of the treatment course 2, 4
- Provoked central venous thrombosis (e.g., from central venous catheter placement, surgery): treat for 3 months minimum 1
- Unprovoked central venous thrombosis or ongoing risk factors (e.g., active malignancy, chronic immobility, thrombophilia): consider indefinite anticoagulation 1
Extended Treatment Phase (Reduced Dose)
- For patients requiring extended anticoagulation beyond 6 months, reduce to apixaban 2.5 mg orally twice daily for secondary prevention 1, 2
- This reduced-intensity dosing was validated in the AMPLIFY-EXTEND trial and minimizes bleeding risk while maintaining efficacy for preventing recurrent VTE 1
- Reassess the risks and benefits of continuing anticoagulation at least annually in all patients on indefinite therapy 1
Special Considerations for Central Venous Thrombosis
Cancer-Associated Central Venous Thrombosis
- Apixaban is a viable option for cancer-associated VTE, showing non-inferiority to dalteparin with similar or lower rates of recurrent VTE (5.6% vs 7.9%) and comparable major bleeding rates (3.8% vs 4.0%) 5
- Consider indefinite anticoagulation for active malignancy 1
Upper Extremity Deep Vein Thrombosis (Including Central Veins)
- For UEDVT with persistent thrombotic risk factors or without recanalization, extended therapy with low-dose apixaban 2.5 mg twice daily after the acute phase is supported by observational data showing no thromboembolic recurrence 6
Critical Contraindications and Dose Adjustments
- Avoid apixaban in severe renal impairment (CrCl <15 mL/min) 2, 4
- Use caution with CrCl <25 mL/min, as 27% of apixaban is renally cleared 4, 7
- Avoid in severe hepatic impairment (transaminases >2x upper limit of normal or total bilirubin >1.5x upper limit of normal) 2, 4
- Contraindicated in patients with intracranial vascular malformations due to high hemorrhage risk 7
Important Pitfalls to Avoid
- Do not shorten the 7-day lead-in period after parenteral anticoagulation in patients with bleeding risk factors, as this increases bleeding events (18.5% vs 5.1%) without reducing VTE recurrence 8
- Concomitant antiplatelet therapy (particularly aspirin) increases major bleeding risk threefold, though apixaban still demonstrates better safety than warfarin in this population 9
- Do not use reduced-dose apixaban (2.5 mg twice daily) before 6 months of full-dose therapy, as this is only validated for extended secondary prevention 1