Blood Tests Required for Patients on Eliquis (Apixaban)
No routine blood monitoring is required for patients on Eliquis (apixaban), unlike warfarin which requires regular INR monitoring. 1
Standard Approach to Monitoring
Apixaban is a direct oral anticoagulant (DOAC) that provides predictable anticoagulation without the need for routine laboratory monitoring. This is one of the key advantages of DOACs over traditional vitamin K antagonists like warfarin.
Initial Baseline Tests
Before starting apixaban, these baseline tests are recommended:
- Complete blood count (CBC)
- Renal function tests (serum creatinine)
- Liver function tests
- Coagulation profile (PT/INR, aPTT)
Ongoing Monitoring
Unlike warfarin, patients on apixaban do not require:
- Regular INR monitoring
- Dose adjustments based on laboratory values
- Routine coagulation tests
Special Situations Requiring Blood Tests
1. Bleeding Episodes
If a patient on apixaban presents with bleeding, the following tests should be ordered:
- Complete blood count (CBC)
- Prothrombin time (PT)
- Activated partial thromboplastin time (aPTT)
- Renal function tests 1
For quantitative assessment of apixaban levels (if available):
- Anti-factor Xa assay calibrated specifically for apixaban 1
2. Before Urgent Procedures
When a patient on apixaban needs an urgent procedure:
- Anti-factor Xa assay (if available)
- PT/INR and aPTT (though these have limitations for DOACs) 1
3. Renal Function Monitoring
Since apixaban is partially eliminated by the kidneys:
- Regular monitoring of renal function is recommended
- More frequent monitoring in patients with impaired renal function
- Dose adjustment may be needed for patients with severe renal impairment 2
Interpreting Test Results
Standard coagulation tests have limitations when assessing apixaban activity:
- PT/INR: May be prolonged but does not reliably correlate with drug levels
- aPTT: May be prolonged but has poor sensitivity
- Anti-factor Xa assay: Most accurate test but not widely available 1
Important Considerations
Renal Function: Patients with severe renal impairment may require dose adjustment and more frequent monitoring of renal function 2
Drug Interactions: Certain medications can affect apixaban levels, requiring closer monitoring
Bleeding Risk: Patients with higher bleeding risk factors may benefit from occasional monitoring of CBC and renal function
Overdose Situations: In cases of suspected overdose, anti-factor Xa levels can help assess the degree of anticoagulation 3
Remember that while routine coagulation monitoring is not required for apixaban, regular clinical follow-up remains important to assess for signs of bleeding or thrombosis, especially in high-risk patients.