Your eGFR of 85 Indicates Normal Kidney Function and Standard Apixaban Dosing
An eGFR of 85 mL/min/1.73 m² represents normal kidney function (Stage G1 or G2 CKD classification), and if you are taking apixaban for atrial fibrillation, you should receive the standard dose of 5 mg twice daily unless you meet at least two of three specific dose-reduction criteria. 1, 2
Understanding Your Kidney Function
Your eGFR of 85 mL/min/1.73 m² falls within the mildly decreased range (60-89 mL/min/1.73 m²) according to KDIGO classification, which is considered Stage G2 CKD. 1 However, this level is:
- Well above the threshold for chronic kidney disease concern (eGFR <60 mL/min/1.73 m²), which is when kidney disease becomes clinically significant 3, 4
- Within the normal range for many adults, particularly if you are older, as GFR naturally declines with age at approximately 0.75 mL/min/year 1
- Not associated with increased risk for medication-related complications in most clinical scenarios 3, 4
Apixaban Dosing at Your Kidney Function Level
Standard Dosing Applies
You should receive apixaban 5 mg twice daily unless you meet at least 2 of the following 3 criteria: 2
- Age ≥80 years
- Body weight ≤60 kg
- Serum creatinine ≥1.5 mg/dL
Only if you meet 2 or more of these criteria should the dose be reduced to 2.5 mg twice daily. 2
Why Your eGFR Doesn't Trigger Dose Reduction
- Apixaban dose adjustments are based on creatinine clearance (CrCl) using the Cockcroft-Gault equation, not eGFR. 1 The FDA label specifically uses serum creatinine ≥1.5 mg/dL as a surrogate marker rather than eGFR values 2
- Your eGFR of 85 mL/min/1.73 m² is far above any threshold requiring dose modification. Dose reduction considerations only begin when CrCl approaches 30 mL/min or lower 1
- At eGFR levels of 60-89 mL/min/1.73 m², apixaban pharmacokinetics show minimal changes (approximately 16% increase in exposure), which is not clinically significant and does not warrant dose adjustment 2
Clinical Implications and Safety
Efficacy and Safety Profile
- Apixaban demonstrates superior safety compared to warfarin across all kidney function levels, including patients with eGFR 50-80 mL/min, with lower rates of major bleeding and stroke 5, 6
- No dose adjustment is needed based on kidney function alone at your eGFR level. 2
- Renal excretion accounts for only 27% of apixaban clearance, making it less dependent on kidney function than other anticoagulants like dabigatran (80% renal clearance) 2
Monitoring Recommendations
- Annual monitoring of kidney function with comprehensive metabolic panel is reasonable for ongoing assessment 4
- Reassess dosing if kidney function declines to eGFR <30 mL/min/1.73 m² or if you develop other dose-reduction criteria 1, 2
- Use Cockcroft-Gault equation (CrCl) rather than eGFR when making anticoagulation dosing decisions, as this is what clinical trials used and what FDA labeling is based on 1
Important Caveats
Equation Discrepancies
Be aware that eGFR equations (CKD-EPI, MDRD) and creatinine clearance (Cockcroft-Gault) can give different values, particularly in elderly patients where eGFR equations may overestimate kidney function by 8.9-13.7 mL/min compared to Cockcroft-Gault. 7 This discrepancy is most pronounced in:
- Patients ≥75 years old 7
- Those with actual CrCl <60 mL/min 7
- Individuals with extremes of body weight or muscle mass 3, 4
When to Reconsider
Contact your physician if you develop: 1
- Significant weight loss (approaching ≤60 kg)
- New kidney disease or worsening kidney function
- Age approaching 80 years (if combined with other criteria)
- Any bleeding complications
Your current eGFR of 85 mL/min/1.73 m² requires no special considerations for apixaban dosing and represents adequate kidney function for standard anticoagulation therapy. 2