Alternative Names digitalis toxicity, digoxin overdose
Definition Digitalis drugs are a class of medications used in some heart conditions. In Australia, digoxin is the main digitalis drug. When the amount of digoxin in the blood becomes too high, toxic effects occur.
What is going on in the body? Digoxin is an effective medication that makes the heart pump better and helps control irregular heartbeats. But, digoxin is also a powerful medication that can cause death if it is taken inappropriately. The greater the amount of digoxin, the greater the risk of toxic effects.
What are the signs and symptoms of the condition? Digoxin toxicity can cause these symptoms:
irregular heartbeats, or arrhythmias, that were not present before
changes in colour vision, such as a yellowish tint to the vision
What are the causes and risks of the condition? Many medications interfere with the body's ability to get rid of digoxin. This may increase the level of digoxin in the blood. These include antibiotics, heart medications, and water pills, or diuretics. Salt imbalances in the body can also increase the risk of digoxin toxicity.
What can be done to prevent the condition? The doctor will often order an electrolyte blood test to check salt balance and a therapeutic drug level to check the level of digoxin. A person should talk with his or her doctor before starting new prescription or over-the-counter medications.
How is the condition diagnosed? Symptoms and findings of new arrhythmias make a doctor suspect digoxin toxicity. A therapeutic drug level blood test can measure the level of digoxin and confirm the diagnosis. In severe cases, changes can be see on an electrocardiograph, or ECG, which records the electrical impulses of the heart.
What are the long-term effects of the condition? In severe cases, digoxin toxicity can sometimes cause death. Treatment is needed right away.
What are the risks to others? There are no risks to others.
What are the treatments for the condition? Mild digoxin toxicity can be treated by lowering the dose. Moderate toxicity may be treated with a short stay in the hospital. There, doctors will watch the person and stop the digoxin for a short time. Other heart medications may be needed to treat the arrhythmias caused by digoxin.
Severe cases are a medical emergency. It may require the use of a pacemaker or powerful heart medications. An antidote is available for severe poisoning. The antidote attaches to the digoxin and stops its toxicity. In all cases, salt imbalances, especially low potassium levels, must be corrected.
What are the side effects of the treatments? Heart medications may cause allergic reactions and new arrhythmias. The antidote may also cause allergic reactions.
What happens after treatment for the condition? After recovery, the person is usually able to return to regular activities.
How is the condition monitored? Close monitoring of salt balance and digoxin blood levels are needed. This helps prevent digoxin from becoming toxic again.
Author: Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request