What adjustments should be made to a patient's anticoagulation regimen who is already taking 2.5mg of Eliquis (apixaban) twice daily and has been diagnosed with a deep vein thrombosis (DVT) in the left common femoral vein?

Immediate Action: Increase Apixaban to Therapeutic Dosing

Your patient is on a prophylactic dose of apixaban (2.5mg BID) and has developed an acute DVT—you must immediately increase to the full therapeutic dose of 10mg twice daily for 7 days, followed by 5mg twice daily for at least 3 months. 1

Why This Happened: Assess for Anticoagulation Failure

The 2.5mg BID dose is only FDA-approved for:

• Reduction of recurrent VTE after completing at least 6 months of therapeutic anticoagulation 1
• Atrial fibrillation in specific patients with dose-reduction criteria 1

This dose provides inadequate anticoagulation for acute VTE treatment. 2

Before proceeding, verify:

• Medication adherence: Confirm the patient has been taking 2.5mg BID consistently 2
• Drug interactions: Check for strong CYP3A4 inducers (rifampin, phenytoin, carbamazepine) that reduce apixaban levels 1
• Underlying hypercoagulable conditions: Active malignancy, antiphospholipid syndrome, or other thrombophilia 2
• Anatomical factors: May-Thurner syndrome or other venous compression 2

Treatment Algorithm

Step 1: Initiate Therapeutic Dosing Immediately

• Apixaban 10mg PO twice daily for 7 days 1, 3
• Then 5mg PO twice daily starting day 8 1, 3
• No bridging with parenteral anticoagulation is required—apixaban can be started directly 1

Step 2: Determine Treatment Duration

For this patient already on anticoagulation who developed breakthrough DVT:

• Extended anticoagulation (indefinite duration) is recommended because this represents recurrent VTE despite anticoagulation 2
• This is a high-risk scenario requiring lifelong therapy with annual reassessment 4, 2

The American College of Chest Physicians specifically recommends extended therapy for patients with recurrent unprovoked VTE 4, and breakthrough thrombosis on inadequate anticoagulation functionally represents recurrent disease 2.

Step 3: Consider Special Circumstances

If active malignancy is present:

• Consider switching to low-molecular-weight heparin (LMWH) as first-line therapy 4
• LMWH is preferred over DOACs in cancer-associated thrombosis 4
• If continuing apixaban, use full therapeutic dose (5mg BID), not reduced dose 4

If no cancer but high bleeding risk:

• After completing 6 months of therapeutic anticoagulation (5mg BID), consider dose reduction to apixaban 2.5mg BID for extended therapy 4
• This reduced-intensity regimen was validated in AMPLIFY-EXTEND for patients completing initial VTE treatment 4

Step 4: Outpatient vs. Inpatient Management

Outpatient management is appropriate if: 2

• Hemodynamically stable
• Adequate home support system
• Phone access and ability to return if deterioration occurs
• No contraindications to anticoagulation

Early ambulation is recommended over bed rest 2

Critical Pitfalls to Avoid

1. Do not continue 2.5mg BID dosing—this is grossly inadequate for acute DVT treatment 1, 2

2. Do not assume the patient was "anticoagulated"—prophylactic dosing does not provide therapeutic anticoagulation 1

3. Do not use aspirin as an alternative—it is vastly inferior to anticoagulation for VTE treatment and prevention 2, 5

4. Do not place an IVC filter unless anticoagulation is absolutely contraindicated (which it is not in this case) 4, 5

5. Do not stop anticoagulation after 3 months—this patient requires extended therapy given breakthrough thrombosis 2

Monitoring and Follow-up

• Reassess at 3 months to confirm therapeutic response and tolerance 4
• After 6 months of therapeutic dosing, consider transition to reduced-dose apixaban 2.5mg BID if bleeding risk is acceptable 4
• Annual reassessment of bleeding risk, renal function, and indication for continued anticoagulation is mandatory 4, 2
• Check renal function before initiating therapy—apixaban is contraindicated if CrCl <15 mL/min 1