Loading Dose of Apixaban for New DVT
The loading dose of apixaban for a new deep vein thrombosis (DVT) is 10 mg orally twice daily for the first 7 days, followed by 5 mg twice daily for continued treatment. 1
Evidence-Based Recommendation
The American College of Cardiology (ACC) provides clear guidance on the dosing regimen for apixaban in venous thromboembolism (VTE) treatment. According to their 2021 expert consensus decision pathway, apixaban should be initiated at 10 mg orally twice daily for the first 7 days, then decreased to 5 mg twice daily for continued treatment 1.
This dosing regimen is consistently supported by:
- The FDA-approved labeling for apixaban, which specifies the same loading dose schedule 2
- The National Comprehensive Cancer Network (NCCN) guidelines, which confirm this dosing approach 1
Clinical Application
Initial Treatment Phase
- Day 1-7: Apixaban 10 mg twice daily
- Day 8 onwards: Apixaban 5 mg twice daily
- No initial parenteral anticoagulation (such as heparin or LMWH) is required before starting apixaban 1
Important Clinical Considerations
- Renal function: Standard dosing is appropriate for patients with creatinine clearance ≥30 mL/min 3
- Drug interactions: Reduce the dose by 50% when coadministered with combined P-glycoprotein and strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) 2
- Monitoring: Regular assessment of renal and hepatic function is recommended, along with monitoring for signs of bleeding 3
Evidence Quality and Efficacy
The AMPLIFY trial demonstrated that this fixed-dose regimen of apixaban was non-inferior to conventional therapy (enoxaparin/warfarin) for the treatment of acute VTE, with significantly less bleeding (0.6% vs 1.8% major bleeding events) 4.
In Japanese patients with acute PE/DVT, the AMPLIFY-J study confirmed that apixaban at this dosing schedule was well-tolerated with a favorable safety profile compared to UFH/warfarin 5.
Special Populations
Cancer Patients
The Caravaggio trial showed that apixaban (using the standard loading dose regimen) was non-inferior to dalteparin for treatment of cancer-associated VTE without increased risk of major bleeding 6.
Extended Treatment
After 6 months of initial therapy, either continuing the 5 mg twice daily dose or reducing to 2.5 mg twice daily can be considered for secondary prevention of VTE 1.
Common Pitfalls to Avoid
Not using the loading dose: Failure to use the higher initial dose may result in suboptimal anticoagulation during the critical first week of treatment.
Confusing with atrial fibrillation dosing: The dosing for DVT/PE treatment (10 mg BID for 7 days, then 5 mg BID) differs from the dosing for atrial fibrillation (5 mg BID, with dose reduction criteria).
Missing the transition: Ensure proper transition from the loading dose (10 mg BID) to the maintenance dose (5 mg BID) after exactly 7 days.
Overlooking drug interactions: P-gp and strong CYP3A4 inhibitors can significantly increase apixaban levels, requiring dose adjustment 2.
The evidence strongly supports this standardized loading dose regimen for apixaban in the treatment of new DVT, with demonstrated efficacy and safety across multiple clinical trials.