Can a 91-year-old patient on warfarin (coumarin) be switched to Eliquis (apixaban)?

Switching from Warfarin to Apixaban in a 91-Year-Old Patient

Apixaban (Eliquis) is a suitable alternative to warfarin for a 91-year-old patient, provided there are no contraindications such as severe renal impairment, and appropriate dose adjustments are made based on age, weight, and renal function.

Benefits of Switching to Apixaban

• Apixaban reduces stroke or systemic embolism by 21% compared to warfarin, with a 31% reduction in major bleeding and an 11% reduction in all-cause mortality 1
• Significantly lower risk of intracranial hemorrhage compared to warfarin, which is particularly important in elderly patients 1
• No need for routine INR monitoring, which can be particularly beneficial for elderly patients who may have difficulty with frequent laboratory visits 2

Dose Considerations for Elderly Patients

• For a 91-year-old patient, the appropriate dose would likely be 2.5 mg twice daily if the patient meets at least two of the following criteria:

  • Age ≥80 years (patient meets this criterion)
  • Body weight ≤60 kg
  • Serum creatinine ≥1.5 mg/dL (133 μmol/L) 1, 3

• If the patient only meets the age criterion and no other criteria, the standard dose of 5 mg twice daily would be appropriate 1, 3

Renal Function Assessment

• Renal function must be evaluated prior to initiating apixaban and should be reassessed periodically 1
• Creatinine clearance (CrCl) should be calculated using the Cockcroft-Gault formula 1
• Apixaban dosing recommendations based on renal function:
  • If CrCl >30 mL/min: Apixaban can be used at appropriate dose 1, 3
  • If CrCl 15-30 mL/min: Limited data available, but apixaban may be considered with caution 4, 5
  • If CrCl <15 mL/min: Apixaban is not recommended 1, 3

Switching Protocol

• Discontinue warfarin and start apixaban when the INR is below 2.0 3
• No bridging therapy with heparin is required when transitioning from warfarin to apixaban 1
• Monitor for any signs of bleeding during the transition period 1

Special Considerations for the Elderly

• Elderly patients (≥80 years) are at higher risk for bleeding complications, but apixaban has shown a favorable safety profile compared to warfarin in this population 6
• Recent studies suggest that apixaban may be safer than other DOACs in very elderly patients regarding major bleeding risk 6
• Drug interactions should be carefully evaluated, particularly with medications that are P-glycoprotein inhibitors or CYP3A4 inhibitors, which may require dose adjustments 3

Monitoring Recommendations

• While routine coagulation monitoring is not required, renal function should be assessed at least annually and when clinically indicated 1
• Monitor for signs and symptoms of bleeding, which should be reported immediately 3
• Ensure patient adherence to the twice-daily dosing regimen, as missed doses can impact efficacy 1

Contraindications and Cautions

• Apixaban is contraindicated in patients with:
  • Active pathological bleeding 3
  • Severe hypersensitivity to apixaban 3
• Use with caution in patients taking concomitant medications affecting hemostasis (aspirin, other antiplatelet agents, NSAIDs) 3
• Temporary interruption may be required before surgical procedures:
  • 48 hours prior to procedures with moderate/high bleeding risk
  • 24 hours prior to procedures with low bleeding risk 3

By following these guidelines, the transition from warfarin to apixaban can be safely managed in a 91-year-old patient, potentially offering advantages in terms of reduced bleeding risk and more convenient management.