What to Know About Digoxin

A Drug Still Used for Heart Failure and Irregular Heartbeats

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Digoxin is used to treat heart failure and abnormal heart rhythms (arrhythmias). It also helps the heart work better and control heart rate. Digoxin may be used after a heart attack. This medication comes in various forms: tablet, capsule, or pediatric elixir (liquid). It is available under the brand names Lanoxin, Cardoxin, Digitek, Digox, and Lanoxicaps. 

Digoxin is in a class of drugs called cardiac glycosides that are used to slow heart rate and improve the filling of the ventricles (two lower chambers of the heart) with blood. For people who have atrial
fibrillation
(irregular heart beat) or heart failure (when heart muscle becomes less effective at pumping blood), this medication can reduce the strain on the heart to allow it to pump blood more effectively.

Despite the benefits of this treatment, digoxin can cause toxicity and trigger a serious cardiac event if too high a dose is consumed or if the level of the drug in the body builds up for other reasons such as taking medications that change the body's tolerance of digoxin. In selecting the correct dose, your doctor will consider factors that affect digoxin blood levels (such as body weight, age, kidney function, and other drugs you are taking) since toxic levels of digoxin are only slightly higher than therapeutic levels.

Uses

Digoxin, originally derived from the foxglove plant, Digitalis purpurea, was mentioned in writings from as early as the year 1250. Since then, the drug has been synthesized and standardized in laboratories for the following uses:

  • To treat mild to moderate heart failure in adults
  • To improve heart contractions in children with heart failure
  • To control heart rhythm in adults with chronic atrial fibrillation

Atrial Fibrillation

Digoxin is a medication often used to treat atrial fibrillation, a common heart rhythm disorder that causes the heart to beat rapidly and irregularly. Digoxin lowers the heart rate and helps bring it under control.

While digoxin can slow the heart rate, it cannot return it to normal. For this, your doctor may prescribe an additional drug such as amiodarone. When adding amiodarone to digoxin drug therapy, it is recommended that concentrations of digoxin be measured and reduced by decreasing the dose by 30% to 50% or by modifying the dose frequency and continuing to monitor the situation.

A study of atrial fibrillation patients taking digoxin-amiodarone combination therapy is associated with a higher death rate than digoxin alone. Death due to non-arrhythmic cardiac disease and certain types of vascular disease was also higher among patients receiving this combination.

An analysis of 19 studies involving more than 500,000 people found that patients taking digoxin to control atrial fibrillation face a 27% greater risk of dying than atrial fibrillation patients not taking digoxin. Patients with both atrial fibrillation and kidney failure appear to face an especially high risk—a 60% to 70% increase in mortality compared with similar patients not taking digoxin.

However, a 2020 study found that Digoxin should be considered as a first-line approach for rate control in older patients with permanent atrial fibrillation (AF). The study showed improved symptoms and reduced adverse events.

Alternative drugs used to treat atrial fibrillation include beta-blockers, calcium-channel blockers, and anti-arrhythmic medications. Procedures such as electrical therapies or surgical procedures like catheter ablation are also helpful in some patients.

Heart Failure

For people with mild to moderate heart failure, digoxin can reduce the strain on the heart, but it is usually used after other drugs have not been successful in treating the condition. Beta blockers and calcium channel blockers are often the drugs of choice because they provide rapid rate control and are effective in reducing the heart rate at rest and during exercise in patients with atrial fibrillation.

However, calcium channel blockers that reduce heart rate (eg non-dihydropyridines such as diltiazem and verapamil) would not be used in patients with a reduced ejection fraction (reduced pumping function of the heart) as they could further worsen the pumping function.

Digoxin was once used to treat advanced heart failure, but has since been replaced by drugs that are more effective and have a lower risk of toxicity.

Digoxin is most often used as adjunctive therapy because of its slower onset of action (usually 60 minutes or more) and its weak potency in slowing electrical signals as they pass through the heart on the way to the ventricles. However, digoxin can be useful in patients with systolic heart failure (when the left ventricle can't contract strongly enough for the blood to move properly).

Off-Label Uses

Digoxin also has numerous off-label uses for conditions such as:

  • Fetal tachycardia: Abnormally rapid heartbeat, above 160-180 beats per minute in a fetus
  • Supraventricular tachycardia: Abnormally fast heartbeat
  • Cor pulmonale: Failure of the right side of the heart. This condition can result from long-term high blood pressure in the arteries of the lungs and right ventricle of the heart
  • Pulmonary hypertension: High blood pressure that affects the arteries in the lungs and the right side of the heart

Digoxin is not approved by the U.S. Food and Drug Administration for use in the above conditions, but it may be an option if the benefits of treatment outweigh the risks in people with treatment-resistant disease. Digoxin is considered adjunctive therapy, rather than first-line therapy, for these conditions.

Before Taking

One of the conditions that digoxin is prescribed for is chronic atrial fibrillation that lasts for more than one week. This condition is diagnosed by different kinds of tests:

  • History and physical exam: The doctor will ask about risk factors, other conditions that you may have, factors that could aggravate the condition, and severity of symptoms
  • Holter monitor: If the doctor suspects atrial fibrillation, he may request a Holter monitor, a small wearable device that provides either a 24-hour or seven-to-30 day recording of your heart rhythms
  • Initial blood test: This includes a complete blood count, an electrolyte panel, a check of thyroid-stimulating hormone, and liver and kidney function tests
  • Echocardiogram: This evaluates cardiac structure and function
  • Chest X-ray: This helps identify any lung disease

Additional testing may be necessary depending history and risk factors. These may include stress echocardiography, nuclear perfusion imaging, or cardiac catheterization to evaluate for coronary artery disease or if your body is not getting enough blood (ischemia). In some cases, drug screening also may be requested, or a sleep study is performed if sleep apnea is suspected.

Mild to Moderate Heart Failure

Digoxin may also be prescribed for mild to moderate heart failure. Doctors usually classify patients' heart failure depending on the severity of the symptoms. The New York Heart Association (NYHA) Functional Classification is most commonly used to place patients in one of four categories based on how much they are limited during physical activity.

There are two components to the classification. One is Functional Capacity, and the classes are:

  • Class I: No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, or dyspnea (shortness of breath)
  • Class II: Slight limitation of physical activity. Comfortable at rest. Ordinary physical activity results in fatigue, palpitation, or dyspnea (shortness of breath)
  • Class III: Marked limitation of physical activity. Comfortable at rest. Less than ordinary activity causes fatigue, palpitation, or dyspnea
  • Class IV: Unable to carry on any physical activity without discomfort. Symptoms of heart failure at rest. If any physical activity is undertaken, discomfort increases

The other part of the classification is Objective Assessment, and the classes are:

  • Class A: No objective evidence of cardiovascular disease. No symptoms and no limitation in ordinary physical activity
  • Class B: Objective evidence of minimal cardiovascular disease. Mild symptoms and slight limitation during ordinary activity. Comfortable at rest
  • Class C: Objective evidence of moderately severe cardiovascular disease. Marked limitation in activity due to symptoms, even during less-than-ordinary activity. Comfortable only at rest
  • Class D: Objective evidence of severe cardiovascular disease. Severe limitations. Experiencing symptoms even while at rest

For example, a person with slight limitation of physical activity and normal coronary arteries (found by testing) is categorized as Functional Capacity II, Objective Assessment A.

Precautions and Contraindications

People with heart failure who take digoxin are commonly given medicines called diuretics that remove excess fluid from the body. Many diuretics can cause potassium loss, and a low level of potassium in the body can increase the risk of digitalis toxicity. Digoxin toxicity may also develop in people who take digoxin and have a low level of magnesium in their body.

You are more likely to have digoxin toxicity if you are also taking drugs that interact with digoxin such as quinidine, flecainide, verapamil, and amiodarone. Normally, digoxin is removed through the urine, but If your kidneys do not work well, this drug can build up in your body. Any problem that affects how your kidneys work (including dehydration) makes digitalis toxicity more likely.

Digoxin is contraindicated for use in people with ventricular fibrillation and anyone with a known hypersensitivity to digoxin or to any ingredient in the drug. Digoxin should also be avoided in people with
myocarditis (heart muscle inflammation, usually caused by a virus) or acute myocardial infarction (heart attack).

Digoxin should be used with extreme caution for people:

  • With significant sinus or AV block (who should first be given a permanent pacemaker before treatment is started)
  • Who are scheduled to undergo electrical cardioversion (in whom the dose should be reduced or temporarily suspended one to two days beforehand to reduce the risk of ventricular arrhythmia)
  • With poor cardiac output but normal left ventricular ejection fraction (LVEF), which can occur with amyloid heart disease (when deposits of an abnormal protein in the heart tissue make it hard for the heart to work properly) and acute cor pulmonale. These people may experience even further decreases in output if digoxin is used

Other Cardiac Glycosides

Another cardiac glycoside, known as Digitaline (digitoxin), is rarely used in Western countries. Unlike digoxin, which is eliminated from the body via the kidneys, digitoxin is eliminated via the liver. It could be used in patients with poor or erratic kidney function. Even so, the evidence supporting its use is lacking.

Dosage

Digoxin is available in three formulations with different doses:

  • Tablets: 62.5 micrograms (mcg), 125 mcg, 187.5 mcg, and 250 mcg
  • Oral solution: 0.05 mg (50 mcg) per 1 milliliter (mL) dose
  • IV injection: 0.5 mg (500 mcg) per 2 mL dose for adults and 0.1 mg (100 mcg) per 2 mL dose for children

Dosage can vary depending on a person’s age, weight, kidney function, any medications they take, and any coexisting medical conditions they have. Oral digoxin is generally preferred; IV digoxin is reserved for urgent situations or if a person is unable to take anything by mouth. Toxic levels of digoxin are only slightly higher than therapeutic levels.

Whether for adults or children, the total daily dose is calculated based on micrograms per kilograms
of body weight per day (mcg/kg/day).

For the treatment of atrial fibrillation, digoxin is usually prescribed with a loading dose, where treatment is initiated with a low dose and gradually increased until the clinical goals are achieved. This helps monitor for toxicity while determining the ideal dose for each person. A loading dose is not needed for heart failure.

Once the clinical goals are achieved, the maintenance dose is taken once daily. Young children may have their daily dose split and take their medication two times per day.

All listed dosages are according to the drug manufacturer. Check your prescription and talk to your doctor to make sure you are taking the right dose for you.

Modifications

Kidney function tests will be routinely performed during treatment with digoxin. Blood tests will also be performed to measure the concentration of digoxin in your blood. If either of these tests falls outside of the expected range of values, the digoxin dose will be adjusted to prevent toxicity.

How to Take and Store

Although food does not typically alter the absorption of the drug, digoxin should not be taken with high-fiber meals, which can slow the absorption or reduce the amount that is absorbed into your blood. All three formulations can be stored safely at 77°F and up to 86°F for short periods of time. Keep the medicine in a dry place and in a tight, light-resistant container. Refer to the manufacturer’s label for information about missed doses and overdosing.

Side Effects

Side effects are common with digoxin. Around 5% to 20% of users will experience heart, gastrointestinal, or central nervous system side effects. Of these people, 15% to 20% will develop severe symptoms.

Common

Contact your doctor if the following side effects are persistent or severe:

  • Apathy, confusion, anxiety, depression, delirium, hallucination
  • Headache
  • Drowsiness
  • Fatigue, weakness
  • Dizziness or lightheadedness
  • Nausea, vomiting
  • Upset stomach or stomach pain
  • Loss of appetite

Severe

A serious concern is digoxin toxicity, a condition that can occur any time during treatment and lead to potentially severe cardiac disturbances, including arrhythmia, ventricular fibrillation, ventricular tachycardia, and sudden cardiac death.

Gynecomastia (englargement of the male breasts) has been occasionally observed following prolonged use of digoxin. Skin rash or other skin reactions may also occur.

Call your doctor if any of the classic signs of digoxin toxicity develop, including:

  • Nausea and vomiting
  • Diarrhea
  • Abdominal pain
  • Delirium
  • Yellow or blurred vision, blind spots, seeing spots
  • Unusual weight gain
  • Difficulty breathing
  • Heart palpitations
  • Swelling of the hands or feet

There is a fine line between a therapeutic dose of digoxin and a toxic one. It is only by taking the drug as prescribed and seeing your doctor regularly that these toxic effects can be avoided.

Warnings and Interactions

Digoxin is a Pregnancy Category C drug, which means the drug should be given to a pregnant woman only if it's clearly needed despite the risks. It is not known whether digoxin can cause fetal harm when administered to a pregnant woman or can affect reproductive capacity. Animal reproduction studies have not been conducted with digoxin. Pregnant women should speak with their doctors to make an informed decision about the benefits and risks of this treatment.

Certain drugs can interfere with the normal metabolization of digoxin, increasing the concentration of the drug in the bloodstream as well as the risk of side effects and toxicity.

Some drugs can increase digoxin concentrations by at least 50%, including:

  • Amiodarone (Cordarone, Pacerone)
  • Captopril (Capoten)
  • Clarithromycin (Biaxin)
  • Dronedarone (Multaq)
  • Gentamicin (Garamycin, Cidomycin)
  • Erythromycin (Erythrocin)
  • Itraconazole (Sporanox)
  • Lapatinib (Tykerb)
  • Propafenone (Rythmol)
  • Quinidine (Quinidex)
  • Ranolazine (Ranexa)
  • Ritonavir (Norvir)
  • Telaprevir (Incivek)
  • Tetracycline (Sumycin, Actisite, Achromycin V)
  • Verapamil (Calan, Isoptin)

To avoid interactions and toxicity, let your doctor know about any medications you are taking, including prescription, over-the-counter, nutritional, herbal, or recreational drugs.

 

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  1. Medline Plus. Digoxin.

  2. Fu J, Wu Z, Zhang L. Clinical applications of the naturally occurring or synthetic glycosylated low molecular weight drugs. Prog Mol Biol Transl Sci. 2019;163:487-522. doi: 10.1016/bs.pmbts.2019.03.005

  3. British Heart Foundation. Digoxin.

  4. Medline Plus. Digitalis toxicity.

  5. GlaxoSmithKline. LANOXIN (digoxin) tablets, for oral use.

  6. Norn S, Kruse PR. Cardiac glycosides: From ancient history through Withering's foxglove to endogeneous cardiac glycosides. Dan Medicinhist Arbog.  2004;119-32.

  7. Chiang, JY, Chen PC, Yang, YH, Chang CH, Chu FY, Chen JJ, Wu CK, Hwang JJ, Chiang FT, Lin LY, Lin JL.. Digoxin-amiodarone combination is associated With excess all-cause mortality in patients with atrial fibrillation. Sci Rep. 2020 Mar 5;10(1):4101. doi: 10.1038/s41598-020-61065-4

  8. American College of Cardiology. Atrial Fibrillation Patients on Digoxin Face Increased Risk of Death. Published March 4, 2015.

  9. Kotecha D, Bunting KV, Gill SK, et al. Effect of Digoxin vs Bisoprolol for Heart Rate Control in Atrial Fibrillation on Patient-Reported Quality of Life: The RATE-AF Randomized Clinical TrialJAMA. 2020;324(24):2497–2508. doi:10.1001/jama.2020.23138

  10. Qureshi W, Alirhayim Z, Ahmed A, Al-Mallah M, AbdulAziz K. Digoxin Use In Atrial Fibrillation Is Associated With Increased Risk Of Mortality: A Systematic Review And Meta-Analysis Of More Than 200,000 Patients. J Am Coll Cardiol. 2015 Mar, 65 (10_Supplement) A289.

  11. Jorge E, Baptista R, Martins H, Saraiva F, Costa S, Vieira H, Coelho L, Monteiro P, Franco F, Providencia LA. Digoxin in advanced heart failure patients: a question of rhythm. Rev Port Cardiol. 2013 Apr;32(4):303-10. doi: 10.1016/j.repc.2012.11.007

  12. DE, Dickerson LM, Sack JL. Acute management of atrial fibrillation: part I. rate and rhythm control. Am Fam Physician. 2002 Jul 15;66(2):249-56.

  13. Chen S. Khusial T, Patel D, Singh S, Yakubova T. Digoxin use in modern medicine. US Pharm. 2015;40(2):44-48.

  14. Guttierez C, Blanchard DG. Diagnosis and treatment of atrial fibrillation. Am Fam Physician. 2016 Sep 15;94(6):442-452. 

  15. American Heart Association. Classes of Heart Failure.

  16. 3DChem.com. Chemistry, Structures & 3D Molecules. Digitoxin.

  17. Roxane Laboratories. Digoxin Oral Solution, USP.

  18. Jubilant HollisterStier General Partnership. LANOXIN (digoxin) injection, for intravenous or intramuscular use Initial U.S.