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 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 this medicine. Ask your doctor about any risk.

Use Digitek (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

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

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 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.

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.