Detailed Drug Information:

DRUG CLASS AND MECHANISM: Digoxin is extracted from the leavesof a plant called digitalis lanata. Digoxin increases the strength andvigor of the heart muscle contractions, and is useful in the treatment ofheart failure. Digoxin also slows the electrical conduction between theatria and the ventricles of the heart, and is useful in treatingabnormally rapid atrial rhythms such as atrial fibrillation, atrialflutter, and atrial tachycardia.

Abnormally rapid atrial rhythms can be caused by heart attacks,excessive thyroid hormones, alcoholism, infections, and many otherconditions. During rapid atrial rhythms, electrical signals from the atriacause rapid contractions of the ventricles. Rapid ventricle contractionsare inefficient in delivering oxygen and nutrients to the body, causingsymptoms of weakness, shortness of breath, dizziness, and even chest pain.Digoxin alleviates these symptoms by blocking the electrical conductionbetween the atria and ventricles, thus slowing ventricle contractions.

PREPARATIONS: tablets (0.125mg, 0.25mg, 0.5mg), capsules(0.05mg, 0.1mg, 0.2mg)

STORAGE: Should be stored in dry, light-resistant, tightcontainer.

PRESCRIBED FOR: Digoxin is used to treat congestive heartfailure and the associated symptoms of shortness of breath when lyingflat, wheezing, and ankle swelling. Digoxin is also used to slow heartrate in rapid atrial rhythm disturbances such as atrial fibrillation andatrial flutter.

DOSING: Digoxin may be taken with or without food. Digoxin ismainly excreted by the kidneys, and dosages need to be reduced in patientswith kidney dysfunction. Digoxin blood levels can be used to monitordosing and to avoid drug toxicity.

DRUG INTERACTIONS: There is little cushion between atherapeutically beneficial level of digoxin and a toxic level of digoxin.Digoxin toxicity is common, especially in patients with kidneydysfunction. Digoxin toxicity can cause potentially life-threatening heartrhythm disturbances, ranging from very slow to rapid ventricular rhythms.In patients with existing disease of the electrical conduction of theheart, digoxin can precipitate heart block and a seriously slow heartrate.

Patients with low blood potassium levels can develop digoxin toxicityeven when digoxin levels are not considered elevated. Similarly, highcalcium and low magnesium blood levels can increase digoxin toxicity andproduce serious heart rhythm disturbances. Drugs such as quinidine,verapamil (Calan), and amiodarone (Cordarone) can increase digoxin levelsand the risk of toxicity. The co-administration of digoxin and betablockers, such as Inderal, or calcium channel blockers, such as Calan, cancause serious slowing of the heart rate.

SIDE EFFECTS: The most common side effects are related todigoxin toxicity and heart rhythm disturbances. Other side effects includeabdominal pain, nausea, vomiting, loss of appetite, breast enlargement, skin rash, blurred vision, and mental changes.