Recommended Initial Dose of Apixaban for Acute Pulmonary Embolism Treatment
The recommended initial dose of apixaban for the treatment of acute pulmonary embolism is 10 mg twice daily for the first 7 days, followed by 5 mg twice daily for at least 3 months. 1, 2
Dosing Regimen Details
The treatment regimen for acute pulmonary embolism with apixaban follows a specific schedule:
- Initial phase: 10 mg twice daily for the first 7 days
- Maintenance phase: 5 mg twice daily for at least 3 months
- Extended treatment phase (if needed): After at least 6 months of treatment, may reduce to 2.5 mg twice daily for extended prophylaxis 3, 2
This regimen was established in the AMPLIFY trial, which demonstrated that apixaban was non-inferior to conventional therapy (enoxaparin/warfarin) for preventing recurrent venous thromboembolism while significantly reducing the risk of major bleeding (0.6% vs 1.8%, relative risk 0.31) 4.
Duration of Treatment
The duration of anticoagulation therapy depends on risk factors:
- 3 months: First PE secondary to a major transient/reversible risk factor 3
- Extended/indefinite anticoagulation:
Special Considerations
Renal impairment: For patients with severe renal impairment (CrCl <30 ml/min), unfractionated heparin followed by vitamin K antagonists is preferred over apixaban 1
Drug interactions: Reduce the dose by 50% when apixaban is coadministered with combined P-glycoprotein and strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, ritonavir) 2
Perioperative management: Discontinue apixaban at least 48 hours before elective surgery with moderate/high bleeding risk, and at least 24 hours before procedures with low bleeding risk 1, 2
Advantages of Apixaban
- Does not require initial parenteral anticoagulation or overlap therapy 1
- Fixed-dose regimen simplifies treatment compared to warfarin 1
- Lower risk of major bleeding compared to conventional therapy 4
Common Pitfalls and Caveats
Missing the initial higher dose: Failing to start with the 10 mg twice daily dose for the first 7 days can lead to inadequate initial anticoagulation.
Inappropriate dose reduction: The 2.5 mg twice daily dose is only for extended treatment after at least 6 months of therapy, not for initial treatment 3.
Monitoring requirements: While routine coagulation monitoring is not required, regular assessment of renal function, hepatic function, and bleeding risk is recommended for patients on extended anticoagulation 3.
Premature discontinuation: Stopping apixaban prematurely increases the risk of thrombotic events. If discontinuation is necessary for reasons other than bleeding, consider coverage with another anticoagulant 2.