Apixaban for DVT Prophylaxis
Apixaban 2.5 mg orally twice daily is FDA-approved and strongly recommended for DVT prophylaxis following hip or knee replacement surgery, with the initial dose taken 12-24 hours post-operatively. 1
FDA-Approved Prophylaxis Indication
Apixaban is specifically indicated for prophylaxis of deep vein thrombosis, which may lead to pulmonary embolism, in patients who have undergone hip or knee replacement surgery. 1
Dosing Regimen for Surgical Prophylaxis
- Standard prophylactic dose: 2.5 mg orally twice daily 1
- Timing of first dose: 12-24 hours after surgery 1
- Duration for hip replacement: 35 days 1
- Duration for knee replacement: 12 days 1
Treatment vs. Prophylaxis Distinction
It is critical to distinguish between prophylaxis and treatment dosing, as they differ substantially:
Treatment Dosing (for established DVT)
- Loading phase: 10 mg orally twice daily for the first 7 days 1, 2
- Maintenance phase: 5 mg orally twice daily after day 7 1, 2
- Extended prophylaxis (after completing ≥6 months of treatment): 2.5 mg twice daily to reduce recurrence risk 1
Guideline Support for Treatment
The 2021 CHEST guidelines provide a strong recommendation for apixaban (along with other DOACs) over vitamin K antagonists for treatment-phase anticoagulation in patients with VTE, based on moderate-certainty evidence showing similar efficacy with reduced bleeding risk. 3
Clinical Evidence for Prophylaxis
Real-world studies demonstrate apixaban's effectiveness in the prophylactic setting:
- A 2021 retrospective study of 230 high-risk THA/TKA patients showed only 0.43% VTE rate with 2.6% wound complications requiring operative treatment, supporting apixaban's safety profile in surgical prophylaxis. 4
- A 2021 comparative study found no significant differences between apixaban 2.5 mg twice daily and enoxaparin 4000 IU daily for preventing DVT or wound complications after total knee replacement (1.5% DVT rate in both groups). 5
Contraindications and Precautions
Renal Function
- Avoid use if creatinine clearance <15 mL/min 1, 2
- Renal elimination accounts for approximately 27% of total drug clearance 2
Hepatic Function
- Avoid use if transaminases >2× upper limit of normal or total bilirubin >1.5× upper limit of normal 2
Neuraxial Anesthesia Warning
The FDA includes a boxed warning regarding spinal/epidural hematoma risk in patients receiving neuraxial anesthesia or spinal puncture while on apixaban. 1 Optimal timing between apixaban administration and neuraxial procedures is not established, but French guidelines recommend avoiding neuraxial procedures when DOA concentrations may still be present. 3
Perioperative Management
When apixaban must be interrupted for other surgical procedures:
- Discontinue 48 hours prior to elective surgery with moderate-to-high bleeding risk 1
- Discontinue 24 hours prior to procedures with low bleeding risk 1
- Restart as soon as adequate hemostasis is established 1
- Bridging anticoagulation during the 24-48 hour interruption is not generally required 1, 3
Special Populations
Cancer Patients
The 2021 CHEST guidelines recommend oral factor Xa inhibitors (including apixaban) over LMWH for cancer-associated thrombosis treatment, though apixaban may be preferred in patients with luminal GI malignancies due to lower bleeding risk compared to rivaroxaban or edoxaban. 3 However, data for prophylactic use in cancer patients remains limited. 2
Antiphospholipid Syndrome
For patients with confirmed antiphospholipid syndrome, vitamin K antagonists are preferred over DOACs during the treatment phase. 3