New Monitoring Recommendations for Digoxin During the Last Decade Are Associated With Decreased Serum Digoxin...

Area of Science:

• Cardiology
• Clinical Chemistry
• Pharmacology

Background:

• Digoxin is a key medication for managing atrial fibrillation and heart failure.
• Therapeutic drug monitoring (TDM) for digoxin has been available since the 1960s.
• Recent research indicates increased mortality risk with serum digoxin levels exceeding 1.0 ng/mL, challenging the traditional 0.8-2.0 ng/mL range.

Purpose of the Study:

• To evaluate trends in serum digoxin concentrations from 2004 to 2024.
• To assess if digoxin levels align with updated clinical recommendations and identify sex-based differences.

Main Methods:

• Retrospective analysis of 37,489 routine digoxin measurements from Uppsala University Hospital (2004-2024).
• Data included patient demographics, sampling dates, and digoxin levels.
• Analytical platforms transitioned from Abbott Architect to Roche Cobas Pro during the study period.

Main Results:

• Median digoxin concentrations were 0.9 nmol/L for males and 1.0 nmol/L for females.
• Approximately 30% of samples exceeded 1.2 nmol/L.
• A statistically significant decrease in digoxin concentrations was observed over time (Spearman R = -0.191, p < 0.000001), particularly for higher values.

Conclusions:

• Serum digoxin levels have declined over the past two decades, reflecting evolving clinical guidelines.
• Despite the downward trend, elevated digoxin levels remain prevalent, underscoring the importance of ongoing alignment between clinical practice and laboratory monitoring.
• Further optimization of digoxin therapy is needed to minimize toxicity risks.