Characteristics of digoxin toxicity attended in Spanish emergency departments according to type of poisoning and administration of digoxin antibodies: the DIGITOX study

Abstract

Background and objective. Digoxin toxicity accounts for a small percentage of poisonings attended by emergency departments. This study aimed to describe differences between acute and chronic digoxin toxicity and assess the use of digoxin-specific antibody fragments (digoxin-Fab) as an antidote. Methods. Retrospective, observational, multicenter study in 15 hospital emergency departments in 8 Spanish autonomous communities in 7 years. We collected patient, clinical and treatment variables, and discharge destination. Patients were classified according to whether toxicity was acute or chronic and whether digoxin-Fab was administered or not. Results. Twenty-seven acute and 631 chronic digoxin poisonings were attended. The mean (SD) patient age was 83.9 (7.9) years, and 76.9% were women. Patients with acute toxicity were younger (80.0 [12] years) than those with chronic toxicity (84.1 [7.7] years) (P < .038), and accidental poisoning was less common (in 85.2% vs 100% in chronic toxicity; P < .001). Cases of acute toxicity were also more serious (Poison Severity Score (29.6% vs 12.5% in chronic toxicity; P < .001). Thirty-four patients were treated with digoxin-Fab (5.4%). These patients were younger (78.7 [11.5] years vs 84.2 (7.6) years), their toxicity was more often acute (in 20.6% vs 3.2% in chronic toxicity), more had attempted suicide (8.8% vs 0.2% with chronic toxicity), and more had severe symptoms (50% vs 11.2%) (P < .001, all comparisons). Hospital admission was required for 76.1%. Overall, mortality was 11.4%. Conclusions. Chronic toxicity accounts for most digoxin poisoning cases, and most patients are women. Acute toxicity is more serious. Patients who required digoxin-Fab have more severe poisoning. Such patients usually have acute toxicity, and attempted suicide is more often the reason for the emergency.