Digoxin is derived from the leaves of a digitalis plant and is used to treat heart failure.

Digoxin is also used to treat atrial fibrillation, a heart rhythm disorder of the atrium (the upper chambers of the heart that allow blood to flow into the heart).

Digoxin may also be used for purposes not listed in this medication guide.

You should not use digoxin if you have a heart rhythm disorder called ventricular fibrillation.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Try to take oral digoxin at the same time every day.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Take digoxin regularly even if you feel fine or have no symptoms. Get your prescription refilled before you run out of medicine completely.

Digoxin injection is given as a shot into a muscle, or as an infusion into a vein. A healthcare provider will give you this injection if you are unable to take the medicine by mouth.

Your blood pressure and heart rate will need to be checked daily.

You may need frequent blood tests. Your kidney function may also need to be checked.

You should not stop taking digoxin suddenly. Stopping suddenly may make your condition worse.

Store at room temperature away from moisture and heat.

You should not use digoxin if you are allergic to it, or if you have ventricular fibrillation (a heart rhythm disorder of the ventricles, or lower chambers of the heart that allow blood to flow out of the heart).

Tell your doctor if you have ever had:

• a serious heart condition such as "sick sinus syndrome" or "AV block" (unless you have a pacemaker);

• a heart attack;

• slow heartbeats that have caused you to faint;

• Wolff-Parkinson-White Syndrome (sudden fast heartbeats);

• kidney disease;

• an electrolyte imbalance (such as low levels of calcium, potassium, or magnesium in your blood);

• a thyroid disorder; or

• if you have recently been sick with vomiting or diarrhea.

Tell your doctor if you are pregnant. It is not known whether digoxin will harm an unborn baby. However, having heart failure or atrial fibrillation during pregnancy may cause complications such as premature birth or low birth weight, or risk of death in both mother and baby. The benefit of treating heart problems with digoxin may outweigh any risks to the baby.

It may not be safe to breast-feed while using digoxin. Ask your doctor about any risk.

Take the medicine as soon as you can, but skip the missed dose if your next dose is due in less than 12 hours. Do not take two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of digoxin can be fatal.

Overdose symptoms may include nausea, vomiting, loss of appetite, and feeling tired.

Avoid becoming overheated or dehydrated during exercise, in hot weather, or by not drinking enough fluids. Digoxin overdose can occur more easily if you are dehydrated.

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Digoxin may cause serious side effects. Call your doctor at once if you have:

• nausea, vomiting, diarrhea, stomach pain;

• fast, slow, or uneven heart rate;

• a light-headed feeling, like you might pass out;

• bloody or black, tarry stools;

• confusion, weakness, hallucinations, unusual thoughts or behavior;

• breast swelling or tenderness;

• blurred vision, yellowed vision; or

• (in babies or children) stomach pain, weight loss, growth delay, behavior changes.

Serious side effects may be more likely in older adults and those who are ill or debilitated.

Common side effects of digoxin may include:

• nausea, diarrhea;

• feeling weak or dizzy;

• headache, weakness, anxiety, depression; or

• rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can affect digoxin. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.