Digoxin toxicity

Digoxin toxicity
Other namesDigoxin poisoning, digoxin overdose
Drawings of Digitalis purpurea
SpecialtyEmergency medicine
Symptomsvomiting, loss of appetite, confusion, blurred vision, changes in color perception, decreased energy
ComplicationsHeart dysrhythmia
CausesExcessive digoxin, plants such as foxglove
Risk factorsLow potassium, low magnesium, high calcium
Differential diagnosisAcute coronary syndrome, hyperkalemia, hypothyroidism, beta blocker toxicity
TreatmentSupportive care, activated charcoal, atropine, digoxin-specific antibody fragments
Frequency~2,500 cases per year (US)

Digoxin toxicity, also known as digoxin poisoning, is a type of poisoning that occurs in people who take too much of the medication digoxin or eat plants such as foxglove that contain a similar substance. Symptoms are typically vague. They may include vomiting, loss of appetite, confusion, blurred vision, changes in color perception, and decreased energy. Potential complications include an irregular heartbeat, which can be either too fast or too slow.

Toxicity may occur over a short period of time following an overdose or gradually during long-term treatment. Risk factors include low potassium, low magnesium, and high calcium. Digoxin is a medication used for heart failure or atrial fibrillation. An electrocardiogram is a routine part of diagnosis. Blood levels are only useful more than six hours following the last dose.

Activated charcoal may be used if it can be given within two hours of the person taking the medication. Atropine may be used if the heart rate is slow while magnesium sulfate may be used in those with premature ventricular contractions. Treatment of severe toxicity is with digoxin-specific antibody fragments. Its use is recommended in those who have a serious dysrhythmia, are in cardiac arrest, or have a potassium of greater than 5 mmol/L. Low blood potassium or magnesium should also be corrected. Toxicity may reoccur within a few days after treatment.

In Australia in 2012 there were about 140 documented cases. This is a decrease by half since 1994 as a result of decreased usage of digoxin. In the United States 2500 cases were reported in 2011 which resulted in 27 deaths. The condition was first described in 1785 by William Withering.