Comparison of creatinine-based equations for estimating renal function for digoxin dose adjustment in patients with...

Area of Science:

• Pharmacology
• Nephrology
• Cardiology

Background:

• Digoxin is crucial for managing atrial fibrillation (AF) and heart failure (HF).
• Accurate renal function estimation is vital for safe digoxin dosing to avoid toxicity.
• Existing equations for estimating glomerular filtration rate (eGFR) may vary in their suitability for digoxin dose adjustment.

Purpose of the Study:

• To identify the most appropriate equation for estimating renal function to guide digoxin dosing in patients with AF and HF.
• To achieve a target serum digoxin trough concentration below 0.9 ng/ml.

Main Methods:

• Patients with AF and HF received a daily oral dose of 0.125 mg digoxin.
• Renal function was estimated using the Modification of Diet in Renal Disease (eGFRMDRD) and Chronic Kidney Disease Epidemiology Collaboration (eGFRCKD-EPI) equations, as well as the Cockcroft-Gault equation.
• Deindexed eGFR values based on body surface area were correlated with serum digoxin trough concentrations.

Main Results:

• The deindexed eGFRMDRD equation showed the highest correlation with digoxin trough concentrations (r = -0.450).
• Median digoxin trough concentrations increased with declining renal function, ranging from 0.60 ng/ml (eGFRMDRD ≥ 60 ml/min) to 1.30 ng/ml (eGFRMDRD < 30 ml/min).

Conclusions:

• The deindexed eGFRMDRD equation is suitable for digoxin dose adjustment in patients with AF and HF.
• Using eGFRMDRD can help optimize digoxin therapy and maintain therapeutic concentrations.