Digoxin treats heart failure, irregular heartbeats and angina, according to MedlinePlus. Derived from the leaves of the Digitalis lanata plant, digoxin causes the heart to contract with more strength and efficiency.
Digoxin comes in the form of a tablet, capsule or liquid that a patient takes orally once a day as directed by his physician. Wait a minimum of two hours after taking digoxin before ingesting antacids or large amounts of fiber, as these can interfere with absorption of digoxin, notes WebMD.
Mild side effects of digoxin include dizziness, rash, sleepiness, heart arrhythmia and vision changes. Serious side effects that require immediate medial attention include stomachache, diarrhea, vomiting, breathing difficulties and swelling of the hands or feet.