Widely differing plasma digoxin values in patients with congestive heart failure and severe liver dysfunction. A...

Area of Science:

• Pharmacology
• Clinical Chemistry
• Cardiology

Background:

• Congestive heart failure (CHF) can lead to secondary liver dysfunction.
• Accurate monitoring of cardiac glycosides like digoxin is crucial in CHF management.
• Existing methods for measuring plasma digoxin may be affected by altered physiological states.

Purpose of the Study:

• To investigate the impact of liver dysfunction secondary to CHF on plasma digoxin levels.
• To compare the performance of three different analytical methods for digoxin measurement in patients with varying degrees of liver dysfunction.
• To identify potential causes for discrepancies in digoxin measurements.

Main Methods:

• Plasma samples were collected from patients with congestive heart failure and no, mild to moderate, or severe liver dysfunction.
• Digoxin levels were determined using three distinct assay methodologies.
• Statistical analysis was performed to compare results across different patient groups and methods.

Main Results:

• Significant discrepancies in plasma digoxin measurements were observed in patients with severe liver dysfunction.
• The degree of discrepancy varied depending on the specific assay method used.
• A digoxin-like immunoreactive substance was implicated as a potential cause for these observed differences.

Conclusions:

• Liver dysfunction secondary to congestive heart failure can profoundly affect plasma digoxin measurements.
• Assay methodology is a critical factor influencing digoxin level accuracy in patients with severe hepatic impairment.
• The presence of interfering substances necessitates careful consideration of analytical methods in this patient population.