Digoxin may be harmful in hemodialysis patients

Digoxin may increase mortality rates in patients with end-stage renal disease undergoing hemodialysis, according to a new study.

Although digoxin is widely used to treat cardiovascular disease, including in patients with end-stage renal disease, its safety in those receiving hemodialysis is unknown. Cellular changes in potassium during the procedure may affect the drug's efficacy and toxicity. Researchers performed an observational cohort study in 120,864 incident dialysis patients to determine the relationship between digoxin and mortality rates. The study results were published early online June 24 by the Journal of the American Society of Nephrology.

Of the 120,864 patients, 4,549 used digoxin. Digoxin use was associated with a 28% higher risk for death in adjusted models (hazard ratio [HR], 1.28; 95% CI, 1.25 to 1.31). Risk for death was also increased in patients with increasing serum digoxin levels (HR, 1.19 per ng/mL increase; 95% CI, 1.05 to 1.35), especially in those with lower levels of potassium before beginning dialysis (HR, 2.53 for potassium levels below 4.3 mEq/L and 0.86 for potassium levels over 4.6 mEq/L). Variables such as patient characteristics, disease severity, and treating physician did not seem to affect the relationship between mortality and high serum digoxin and low serum potassium levels.

The study had potential unmeasured confounders, such as lack of information on cardiac parameters, and some patients may have been misclassified based on medical record data, among other limitations, the authors noted. However, they concluded that digoxin is associated with mortality in patients undergoing hemodialysis and that it should be used with caution in this group. "Strict [potassium] and digoxin level management is recommended when patients with [end-stage renal disease] remain on digoxin until its overall safety is better evaluated through randomized, controlled trials," they wrote.