Examples

How It Works

Cardiac glycosides slow and strengthen the heartbeat by affecting the natural electrical system of the heart.

Why It Is Used

Cardiac glycosides most often are used to treat severe heart failure and atrial fibrillation that can occur with congenital heart defects. These conditions are more common in complex defects, such as:

• Tetralogy of Fallot.
• Transposition of the great vessels.
• Atrial septal defect or other defects involving the upper chambers (atria) of the heart.

It sometimes takes several weeks to determine the correct dose of this medicine. Cardiac glycosides most often are taken as pills but are also available in liquid form.

How Well It Works

Cardiac glycosides help:

• Control rapid irregular heartbeats.
• Reduce the backup of blood and fluid in the body that can cause swelling in the arms and legs and difficulty breathing.
• Increase blood flow through the kidneys, which helps get rid of salt (sodium) and relieves swelling in the tissues of the body.

Side Effects

The most common side effects of cardiac glycosides include:

• Buildup of the medicine in the body. Symptoms include confusion, nausea, loss of appetite, and trouble with vision.
• Slow (bradycardia) or rapid (tachycardia) heartbeats, especially in people who are also taking diuretics.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Cardiac glycosides are one of the most commonly prescribed medicines to treat heart failure, but there is some controversy over their use. Talk with your doctor if you have questions.

Regular blood tests may be done to monitor levels of cardiac glycosides.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.