Age- and Gender-Specific Incidence of Hospitalisation for Digoxin Intoxication

Abstract

The safety of digoxin (digitalis) therapy has greatly improved over the past three decades, but recent incidence rates for digoxin intoxication-related hospitalisation are not available. Recent literature suggests that women are at higher risk of digoxin toxicity. To provide age- and gender-specific incidence rates for digoxin intoxication-related hospitalisation and mortality during digoxin intoxication-related hospitalisation in The Netherlands in the period 2001-4. We conducted a nationwide population-based cohort-study of all hospital admissions in the years 2001-4 using a national computerised hospital admission registry. All patients with acute admissions were included in the study (n = 2 987 580). From these admissions, we selected all hospitalisations that had digoxin intoxication coded as either a primary or secondary diagnosis. We obtained data on digoxin prescriptions from the Foundation for Pharmaceutical Statistics (Stichting Farmaceutische Kengetallen) pharmacy database, which extrapolates drug figures for The Netherlands from prescriptions dispensed by 90% of all community pharmacies. We computed age- and gender-specific incidence rates of digoxin intoxication. Digoxin intoxication was identified in 0.04% (n = 1286) of acute admissions. The incidence rate for digoxin intoxication-related admission was 48.5 ( 95% CI 45.9, 51.2) per 100 000 prescriptions, which corresponds to 1.94 admissions for intoxication per 1000 treatment-years. Women had a 1.4-fold higher risk of intoxication than men (95% CI 1.3, 1.6). The age- and gender-adjusted relative risk of mortality in patients with digoxin intoxication compared with those admitted for other reasons was 0.7 (95% CI 0.5, 0.8). This study shows that digoxin intoxication in patients receiving current therapy is presently infrequent and that women are at higher risk of digoxin intoxication than men.