Is a glomerular filtration rate (GFR) of 25 and creatinine level of 149 micromoles per liter adequate for continuation of apixaban (Apixaban) 2.5 milligrams twice daily in a 97-year-old patient with atrial fibrillation?

From the Guidelines

Yes, the patient's renal function is adequate to continue apixaban 2.5 mg twice daily. The current dose of apixaban 2.5 mg BID is appropriate for this 97-year-old patient with atrial fibrillation who has a GFR of 25 mL/min, creatinine of 149 μmol/L, and weight of 100 kg. According to the latest guidelines, apixaban can be used in patients with a GFR as low as 15 mL/min, though dose adjustment is recommended for patients meeting certain criteria 1. This patient is already on the reduced dose of 2.5 mg BID, which is appropriate given her age (≥80 years) and renal function. While her weight of 100 kg would not typically warrant dose reduction (low weight <60 kg is a criterion for dose reduction), her advanced age and reduced renal function support the current dosing.

Some key points to consider:

• The benefit of stroke prevention in atrial fibrillation likely outweighs bleeding risk, especially since she has no history of bleeding or falls 1.
• Regular monitoring of renal function is still advisable, as any further decline below 15 mL/min would warrant reconsideration of anticoagulation options 1.
• The 2018 European Heart Rhythm Association practical guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation also supports the use of apixaban 2.5 mg BID in patients with severe renal impairment 1.
• The American Heart Association and other organizations have published guidelines that support the use of apixaban in patients with atrial fibrillation and renal impairment, with dose adjustments as needed 1.

Overall, the current dose of apixaban 2.5 mg BID is appropriate for this patient, and regular monitoring of renal function is necessary to ensure the continued safety and efficacy of this treatment.

From the FDA Drug Label

In patients with at least 2 of the following characteristics: age greater than or equal to 80 years, body weight less than or equal to 60 kg, or serum creatinine greater than or equal to 1.5 mg/dL, the recommended dose is 2.5 mg orally twice daily. (2.1)

The patient's age is 97 years, which meets the first criterion, and her serum creatinine is 149 μmol/L, which is approximately 1.68 mg/dL, meeting the third criterion. However, her weight is 100 kg, which does not meet the second criterion.

• The patient is already on the reduced dose of 2.5 mg bid due to her age.
• Her renal function is a concern, with a GFR of 25 and creatinine of 1.68 mg/dL (or 149 μmol/L), but the label does not provide a clear guideline for renal impairment with a GFR as low as 25. Since the label does not explicitly address renal function with a GFR of 25, no conclusion can be drawn about the adequacy of her renal function to continue on apixaban 2.

From the Research

Patient's Renal Function and Apixaban Use

• The patient's renal function is a crucial factor in determining the suitability of apixaban therapy, with a creatinine clearance (CrCl) of 25 mL/min and serum creatinine (SCr) of 149 mg/dL 3, 4, 5.
• Studies have shown that apixaban can be used in patients with severe renal impairment, including those with CrCl < 25 mL/min, although the evidence is based on limited pharmacokinetic data and clinical trials have excluded patients with CrCl < 25 mL/min 3, 4, 5.
• The patient's weight of 100 kg is also an important consideration, as apixaban dosing may need to be adjusted based on body weight 6, 7.

Safety and Efficacy of Apixaban in Patients with Renal Dysfunction

• Several studies have compared the safety and efficacy of apixaban with warfarin in patients with renal dysfunction, including those with stage 4 and 5 chronic kidney disease (CKD) 3, 4, 7, 5.
• The results of these studies suggest that apixaban may be a reasonable alternative to warfarin in patients with severe renal impairment, with similar efficacy and a potentially better safety profile in terms of bleeding risk 3, 4, 7, 5.
• A systematic review of 11 studies found that apixaban had equivalent efficacy to warfarin for the prevention of stroke, systemic embolization, and recurrent venous thromboembolism, and a similar or better safety profile in terms of bleeding risk 5.

Clinical Considerations

• The patient's lack of bleeding or falls history is an important consideration, as it may affect the risk-benefit assessment of apixaban therapy 6, 7.
• The patient's atrial fibrillation diagnosis and need for anticoagulation therapy must also be taken into account, as apixaban is indicated for stroke and systemic embolism risk reduction in patients with non-valvular atrial fibrillation 3, 4, 7, 5.