ICU · toxicology

Acute Digoxin Toxicity — Comprehensive ICU Management

Also known as Digoxin toxicity · Digoxin overdose · Cardiac glycoside toxicity · DigiFab · Digoxin immune fab · Xanthopsia · Bidirectional VT · Stone heart

Digoxin toxicity — Na/K-ATPase inhibition: gastrointestinal signs, bradycardia and heart block predominate; death is from ventricular fibrillation or tachycardia; hyperkalaemia in acute overdose marks severity (each 1 mmol/L rise increases mortality odds). Chronic toxicity (commonest — elderly, renal impairment, drug interactions such as amiodarone and quinidine) is harder to recognise than acute overdose and can occur at 'therapeutic' levels. Visual toxicity ranges from xanthopsia (yellow vision) to isolated reduced acuity. Characteristic rhythm: bidirectional VT (alternating His-Purkinje foci). Management: digoxin-specific antibody fragments (40 mg vial binds 0.5 mg digoxin) for life-threatening tachy-bradyarrhythmias, hyperkalaemia over 6 mmol/L, or haemodynamic instability with digoxin over 2 µg/L — 80% complete resolution, median response 19 min in the landmark 150-patient series; titrate rather than give the full calculated neutralising dose (80 mg bolus acute; 1 vial repeated at 60 min chronic). Magnesium sulfate is the established antiarrhythmic adjunct. Calcium remains a listed controversy — Levine found no excess malignant dysrhythmia or mortality, but caution persists. Post-Fab TOTAL digoxin levels are uninterpretable — follow FREE digoxin and the clinical picture. Historical mortality of acute digitalis poisoning was reported at 3-25%; with Fab, 54% of arrested patients survived hospitalisation.

Checked against its sources on 14 Oct 2026