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

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