From the Guidelines
Digoxin toxicity is characterized by a range of symptoms, including gastrointestinal disturbances, cardiac manifestations such as bradycardia and arrhythmias, and neurological symptoms like confusion and visual disturbances, and should be suspected in patients taking the medication who present with these symptoms, especially if they have recently had a dose increase or started taking interacting medications, as stated in the 2018 guideline 1. The signs of digoxin toxicity can be divided into several categories, including:
- Gastrointestinal disturbances, such as nausea, vomiting, abdominal pain, and diarrhea
- Cardiac manifestations, including bradycardia, various arrhythmias, heart blocks, and ventricular ectopy
- Neurological symptoms, such as confusion, disorientation, headache, fatigue, weakness, and visual disturbances like blurred vision, yellow-green halos around objects, or color vision abnormalities
- Electrolyte imbalances, particularly hypokalemia, hypomagnesemia, and hypercalcemia, which can increase the risk of digoxin toxicity Elderly patients and those with renal impairment are at higher risk for developing toxicity, even at therapeutic doses, as noted in the 2013 guideline 1. The diagnosis of digoxin toxicity is established by the combination of characteristic rhythm disturbances, ancillary symptoms, and elevated serum concentrations, and treatment is based on the severity, with mild cases managed by discontinuing the medication and monitoring rhythm, and more severe cases requiring administration of digoxin-specific Fab antibody, as recommended in the 2018 guideline 1. It is essential to promptly recognize digoxin toxicity, as severe toxicity can be life-threatening, and may require administration of digoxin-specific antibody fragments (Digibind) in addition to supportive care, as stated in the 2010 guideline 1. The use of digoxin-specific antibody (Fab) is a critical component of the management of digoxin toxicity, with clinical response rates as high as 80% to 90%, particularly in the acute setting, as noted in the 2019 guideline 1.
From the FDA Drug Label
In this trial, the most common manifestations of digoxin toxicity included gastrointestinal and cardiac disturbances; CNS manifestations were less common. High doses of digoxin may produce a variety of rhythm disturbances, such as first-degree, second-degree (Wenckebach), or third-degree heart block (including asystole); atrial tachycardia with block; AV dissociation; accelerated junctional (nodal) rhythm; unifocal or multiform ventricular premature contractions (especially bigeminy or trigeminy); ventricular tachycardia; and ventricular fibrillation. Digoxin may cause anorexia, nausea, vomiting, and diarrhea Digoxin can produce visual disturbances (blurred or yellow vision), headache, weakness, dizziness, apathy, confusion, and mental disturbances (such as anxiety, depression, delirium, and hallucination) The earliest and most frequent manifestation of excessive dosing with digoxin in infants and children is the appearance of cardiac arrhythmias, including sinus bradycardia.
The signs of digoxin toxicity include:
- Gastrointestinal disturbances: anorexia, nausea, vomiting, diarrhea, abdominal pain
- Cardiac disturbances:
- Rhythm disturbances: first-degree, second-degree, or third-degree heart block, atrial tachycardia with block, AV dissociation, accelerated junctional rhythm, ventricular premature contractions, ventricular tachycardia, ventricular fibrillation
- Cardiac arrhythmias: sinus bradycardia, conduction disturbances, supraventricular tachyarrhythmias
- CNS manifestations: visual disturbances, headache, weakness, dizziness, apathy, confusion, mental disturbances (anxiety, depression, delirium, hallucination) 2 2
From the Research
Signs of Digoxin Toxicity
The signs of digoxin toxicity can vary and may include:
- Anorexia, nausea, vomiting, and neurological symptoms 3
- Fatal arrhythmias 3
- Cardiotoxic effects 4
- A wide range of symptoms and cardiac arrhythmias 5
Clinical Presentation
Digoxin toxicity can occur even when the serum digoxin concentration is within the therapeutic range 3. The clinical presentation of digoxin toxicity can be nonspecific, making diagnosis challenging 6.
Diagnosis and Management
The diagnosis and management of digoxin toxicity require consideration of the time of ingestion and nature of the exposure (ie, acute, acute-on-chronic, chronic) 6. Digoxin immune Fab may be used to treat life-threatening exposure and decrease the risk of death 6.
Mortality Risk
Elevated serum digoxin levels have been linked to a higher risk of death in patients with heart failure or atrial fibrillation, even without signs or symptoms of toxicity 5. However, the use of digoxin to control ventricular rate in patients with atrial fibrillation and heart failure is not associated with increased mortality 7.