Emergency department visits and hospitalizations for digoxin toxicity: United States, 2005 to 2010

Abstract

Background: Recent data on digoxin prescribing and adverse events are lacking but could help inform the management of digoxin in contemporary heart failure treatment.

Methods and results: We determined nationally representative numbers and rates of emergency department (ED) visits for digoxin toxicity in the United States using 2005 to 2010 reports from the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance project and the National Ambulatory (and Hospital Ambulatory) Medical Care Surveys. Based on 441 cases, an estimated 5156 (95% confidence interval [CI], 2663-7648) ED visits for digoxin toxicity occurred annually in the United States; more than three fourths (78.8% [95% CI, 73.5%-84.1%]) resulted in hospitalization. Serum digoxin level was ≥2.0 ng/mL for 95.8% (95% CI, 93.2%-98.4%) of estimated ED visits with levels reported (n=251 cases). The rate of ED visits per 10 000 outpatient prescription visits among patients≥85 years was twice that of patients 40 to 84 years (rate ratio, 2.4 [95% CI, 1.2-5.0]); among women, the rate was twice that of men (rate ratio, 2.3 [95% CI, 1.1-4.7]). Digoxin toxicity accounted for an estimated 1.0% (95% CI, 0.6%-1.4%) of ED visits for all adverse drug events among patients≥40 years, but an estimated 3.3% (95% CI, 2.3%-4.4%) of ED visits and 5.9% (95% CI, 4.0%-7.9%) of hospitalizations for all adverse drug events among patients≥85 years. Estimated annual ED visits and hospitalizations remained relatively constant from 2005 to 2010.

Conclusions: Digoxin toxicity is not declining; more careful prescribing to high-risk groups and improved monitoring of serum levels might be needed to reduce morbidity from outpatient digoxin use.

Keywords: digoxin; drug-related side effects and adverse reactions; emergency service, hospital; heart failure; hospitalization.