Determining the Risk of Elevated Digoxin Concentrations Following Loading Dose in Patients With Acute and Chronic...

Area of Science:

• Pharmacology
• Nephrology
• Internal Medicine

Background:

• Optimal digoxin loading doses for patients with impaired kidney function remain unclear.
• Previous recommendations for reduced doses were based on outdated immunoassays affected by digoxin-like substances.
• Modern assays minimize interference, necessitating re-evaluation of digoxin dosing in renal impairment.

Purpose of the Study:

• To investigate the association between reduced kidney function (acute kidney injury and chronic kidney disease) and supratherapeutic digoxin concentrations after a loading dose.
• To compare digoxin peak concentrations in patients with AKI, CKD, and normal kidney function (NKI).

Main Methods:

• Retrospective analysis of 146 patients receiving intravenous digoxin loading doses.
• Patients were categorized into AKI, CKD, and NKI groups based on renal function.
• Primary outcome: frequency of supratherapeutic digoxin concentrations (>2 ng/mL); secondary outcome: adverse events.

Main Results:

• Supratherapeutic digoxin concentrations were observed in 10.2% of AKI, 18.8% of CKD, and 11.3% of NKI patients (P = 0.61).
• Logistic regression showed no significant relationship between kidney function group and supratherapeutic concentrations (AKI OR: 1.3, 95% CI: 0.4-4.5; CKD OR: 4.3, 95% CI: 0.7-23).
• The CKD group was underpowered for definitive conclusions.

Conclusions:

• This study did not find a relationship between kidney function (AKI or CKD) and peak digoxin concentrations in routine clinical practice.
• Further research with larger sample sizes, particularly for the CKD population, is warranted.
• Current findings suggest that standard digoxin loading doses may be appropriate across different levels of kidney function, pending further investigation.