Digoxin is used to treat heart failure, usually along with other medications. It is also used to treat certain types of irregular heartbeat (such as chronic atrial fibrillation). Treating heart failure may help maintain your ability to walk and exercise and may improve the strength of your heart. Treating an irregular heartbeat can also improve your ability to exercise.

Digoxin belongs to a class of medications called cardiac glycosides. It works by affecting certain minerals (sodium and potassium) inside heart cells. This reduces strain on the heart and helps it maintain a normal, steady, and strong heartbeat.

Take this medication by mouth with or without food as directed by your doctor, usually once daily. If you are using the liquid form of this medication, carefully measure the dose using the dropper provided by the manufacturer. Do not use a household spoon because you may not get the correct dose.

Your body may not absorb this drug as well if you also eat foods that are high in fiber or if you take certain medications. Take this medication at least 2 hours before or after eating food products that are high in fiber (such as bran). If you are also taking cholestyramine, colestipol, or psyllium, wait at least 2 hours after taking your digoxin dose before taking any of these products. If you are taking antacids, kaolin-pectin, milk of magnesia, metoclopramide, sulfasalazine, or aminosalicylic acid, take them as far apart from your digoxin dose as possible. Ask your pharmacist if you are not sure when to take any of your medications.

The dosage of this medication is based on your medical condition, age, body weight, lab tests, and response to treatment.

Use this medication regularly to get the most benefit from it. To help you remember, use it at the same time each day. Do not stop taking this medication without consulting your doctor. Some conditions may become worse when the drug is suddenly stopped.

Tell your doctor if your condition does not get better or if it gets worse.

Nausea, vomiting, headache, dizziness, loss of appetite, and diarrhea may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• weakness
• mental/mood changes
• vision changes (such as blurred or yellow/green vision)
• enlarged/tender breasts in men

Though this medication is used to treat a certain type of irregular heartbeat, it may rarely cause other types of irregular heartbeats. Tell your doctor right away if you notice any unusually fast/slow/irregular heartbeat.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking digoxin, tell your doctor or pharmacist if you are allergic to it; or to similar drugs (such as digitoxin); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• kidney problems
• thyroid problems (underactive or overactive)

This drug may make you dizzy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

The balance of certain natural minerals in your blood (calcium, magnesium, potassium) can affect how this drug works in your body. Certain drugs such as "water pills" (diuretics) may affect the normal balance of these minerals. Tell your doctor or pharmacist if you are taking a "water pill" or if you have a history of mineral imbalance. Ask your doctor or pharmacist whether you should take a nutritional supplement or follow a special diet.

Before having surgery or certain procedures on your heart (such as electrical cardioversion), tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Infants and children may be more sensitive to the effects of this drug, especially the effects on the heartbeat.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

Digoxin passes into breast milk, but is unlikely to harm a nursing infant. Consult your doctor before breastfeeding.

See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Other medications can affect the removal of digoxin from your body, which may affect how digoxin works. Examples include azole antifungals (such as itraconazole), dronedarone, lapatinib, macrolide antibiotics (such as clarithromycin, erythromycin), propafenone, St. John's wort, among others.

Some products have ingredients that could worsen your heart failure. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products, diet aids, or NSAIDs such as ibuprofen/naproxen).

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as digoxin levels, mineral levels in the blood, kidney function, electrocardiograms) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

Check your blood pressure and pulse (heart rate) regularly while taking this medication. Learn how to check your own blood pressure and pulse at home, and share the results with your doctor.

If you miss a dose, take it as soon as you remember. If it is more than 12 hours after the missed dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up. If you miss more than 2 doses in a row, ask your doctor or pharmacist right away for a new dosing schedule.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.