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

The patient's renal function is adequate to continue apixaban 2.5 mg twice daily, as the current dose is appropriate for her age, weight, and renal function, with a GFR of 25 mL/min. According to the guidelines, apixaban can be used in patients with a GFR as low as 15 mL/min, with dose adjustment recommended for patients meeting certain criteria, such as age ≥80 years, weight <60 kg, or serum creatinine >133 mmol/L 1. This patient is already on the reduced dose of 2.5 mg BID, which is appropriate given her age and renal function. While her weight of 100 kg would not typically warrant dose reduction, her advanced age and reduced renal function support the current dosing.

Key Considerations

• Regular monitoring of renal function is advisable, as any further decline below 15 mL/min would necessitate reconsideration of anticoagulation options.
• The benefit of stroke prevention in atrial fibrillation likely outweighs bleeding risks, especially since she has no history of bleeding or falls.
• The guidelines suggest that treatment should be individualized, and the dose adapted on the basis of CrCl according to licensed indications 1.

Monitoring and Follow-up

• Closely monitor renal function, especially in NOAC users.
• Schedule for frequent clinical follow-up, look for development of new cardiovascular risk factors, comorbidities.
• Reassess and address bleeding risk factors. The latest systematic review and meta-analysis by Harel et al found that the use of warfarin was not associated with ischemic stroke or ICH (hemorrhagic stroke) among patients who have AF and receive dialysis, however, there was marked study heterogeneity including the inability to account for major confounders such as the quality of anticoagulation control (TTR) 1.

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 for atrial fibrillation treatment. With a GFR of 25 and creatinine level of 149, the patient has severe renal impairment.

Studies on Apixaban Use in Patients with Severe Renal Impairment

• A study published in 2017 3 compared the safety and effectiveness of apixaban versus warfarin in patients with severe renal impairment and found that apixaban appears to be a reasonable alternative to warfarin in this population.
• Another study from 2024 4 evaluated the use of apixaban in patients with advanced kidney disease and found that patients on apixaban had low major bleeding and similar overall bleeding rates compared to previously published literature.
• A 2021 study 5 found that apixaban might be a reasonable alternative to warfarin in patients with severe renal impairment, with no significant difference in the rates of stroke, systemic embolism, or major bleeding.
• A 2018 review 6 suggested that apixaban may be superior to warfarin in patients with an eGFR < 25 mL/min, but large-scale, randomized clinical trials are needed to validate these results.
• A 2022 systematic review 7 found that apixaban has similar efficacy and somewhat superior safety profile to warfarin in patients with Stage 4 or 5 CKD and receiving dialysis.

Key Findings

• Apixaban may be a reasonable alternative to warfarin in patients with severe renal impairment.
• The risk of bleeding associated with apixaban is similar to or lower than warfarin in patients with severe renal impairment.
• Large-scale, randomized clinical trials are needed to further validate the safety and efficacy of apixaban in this population.

Considerations for the Patient's Treatment

• The patient's weight of 100 kg and lack of bleeding or falls history should be taken into account when considering the use of apixaban.
• The patient's renal function and other comorbidities should be closely monitored while on apixaban therapy.