Apixaban Dosing for DVT Treatment
For a patient with acute deep vein thrombosis (DVT) of the right calf vein who has been started on Eliquis (apixaban), the recommended dosing regimen is 10 mg orally twice daily for the first 7 days, followed by 5 mg orally twice daily for at least 3 months. 1, 2, 3
Initial Treatment Phase (Days 1-7)
- Start with 10 mg orally twice daily for exactly 7 days to achieve rapid anticoagulation without requiring initial parenteral therapy (heparin or enoxaparin). 1, 2, 3
- This loading dose regimen provides immediate therapeutic anticoagulation and eliminates the need for bridging with injectable anticoagulants, unlike warfarin. 2, 4
- The first dose should be taken as soon as the diagnosis is confirmed and treatment is initiated. 3
Maintenance Phase (Day 8 onwards)
- After completing 7 days at 10 mg twice daily, reduce to 5 mg orally twice daily for the remainder of treatment. 1, 2, 3
- Continue this maintenance dose for a minimum of 3 months for provoked DVT (such as this case with an identifiable risk factor). 1, 2
- For unprovoked DVT or patients with ongoing risk factors, consider extending treatment beyond 3 months. 2
Evidence Supporting This Regimen
- The AMPLIFY trial demonstrated that this dosing strategy (10 mg twice daily for 7 days, then 5 mg twice daily for 6 months) was non-inferior to conventional enoxaparin/warfarin therapy for preventing recurrent VTE. 5, 1
- Major bleeding was significantly lower with apixaban (0.6%) compared to conventional therapy (1.8%), making it a safer option. 1
- This regimen has been validated in Japanese populations and shows consistent safety and efficacy across diverse patient groups. 6
Extended Treatment Considerations
- If anticoagulation is needed beyond 6 months for secondary prevention, reduce the dose to 2.5 mg orally twice daily to minimize bleeding risk while maintaining efficacy against recurrent DVT. 2, 3
- Recent evidence shows that even for provoked VTE with enduring risk factors, extended therapy with apixaban 2.5 mg twice daily significantly reduces recurrent VTE (1.3% vs 10.0% with placebo) with minimal major bleeding risk. 7
Key Advantages Over Traditional Therapy
- No routine laboratory monitoring is required (no INR checks, no aPTT monitoring), unlike warfarin or unfractionated heparin. 1, 2
- No initial parenteral anticoagulation needed, simplifying outpatient management. 2, 4
- Fixed-dose regimen provides predictable anticoagulation without dose adjustments based on weight (except in special populations). 4
Critical Contraindications and Warnings
- Avoid in severe renal impairment (CrCl <15 mL/min) and use caution if CrCl <25 mL/min, as these patients were excluded from clinical trials. 1
- Do not discontinue prematurely without transitioning to another anticoagulant, as this increases thrombotic risk significantly. 3
- Extreme caution with neuraxial anesthesia or spinal procedures due to risk of spinal/epidural hematoma; discontinue at least 48 hours before elective procedures with moderate-to-high bleeding risk. 3
Baseline and Monitoring Requirements
- Obtain baseline CBC, renal function (creatinine clearance), hepatic function panel, aPTT, and PT/INR before initiating therapy. 5
- Monitor hemoglobin, hematocrit, and platelet count every 2-3 days for the first 14 days, then every 2 weeks thereafter to detect occult bleeding early. 5
- No routine coagulation monitoring (INR/aPTT) is needed during maintenance therapy. 1
Special Population: Cancer-Associated DVT
- While LMWH (particularly dalteparin) remains the preferred first-line therapy for cancer-associated VTE, apixaban is an acceptable alternative for patients who refuse or cannot tolerate injections. 5, 2
- Recent evidence supports apixaban as noninferior to dalteparin for cancer-associated VTE. 2