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Does Lanoxin (digoxin) cause side effects?
Lanoxin (digoxin) is a cardiac glycoside that increases the strength and efficiency of heart contractions, and is used to treat mild to moderate congestive heart failure and to treat atrial fibrillation, an abnormal heart rhythm. It also is used for increasing myocardial contractility in pediatric patients with heart failure.
Lanoxin increases the force of contraction of the muscle of the heart by inhibiting the activity of an enzyme (ATPase) that controls movement of calcium, sodium, and potassium into heart muscle. Calcium controls the force of contraction. Inhibiting ATPase increases calcium in heart muscle and therefore increases the force of heart contractions.
Lanoxin also slows electrical conduction between the atria and the ventricles of the heart and is useful in treating abnormally rapid atrial rhythms such as atrial fibrillation, atrial flutter, and atrial tachycardia. (Abnormally rapid atrial rhythms can be caused by heart attacks, excessive thyroid hormones, alcoholism, infections, and many other conditions.)
During rapid atrial rhythms, electrical signals from the atria cause rapid contractions of the ventricles. Rapid ventricular contractions are inefficient in pumping blood containing oxygen and nutrients to the body, causing symptoms of
Lanoxin alleviates these symptoms by blocking the electrical conduction between the atria and ventricles, thus slowing ventricular contractions.
Common side effects of Lanoxin include
Lanoxin has also been associated with
- visual disturbance (blurred or yellow vision),
- abdominal pain, and
- breast enlargement.
Serious side effects of Lanoxin include
- heart block,
- rapid heartbeat, and
- slow heart rate.
Drug interactions of Lanoxin include gentamicin, tetracycline, ranolazine, verapamil, quinidine, amiodarone, indomethacin, alprazolam, spironolactone, and itraconazole, which can increase Lanoxin levels and the risk of toxicity.
- The co-administration of Lanoxin and beta-blockers or calcium channel blockers or CCBs, which also reduce heart rate, can cause serious heart rate slowing.
- Diuretic-induced (for example, by furosemide) reduction in blood potassium or magnesium levels may predispose patients to Lanoxin-induced abnormal heart rhythms.
- Saquinavir and ritonavir increase the amount of Lanoxin in the body and may cause Lanoxin toxicity.
- Mirabegron increases Lanoxin blood levels.
- The lowest dose of Lanoxin should be used by people who are also using mirabegron.
- Omeprazole and other drugs that reduce stomach acidity may increase blood levels of Lanoxin.
There are no adequate studies of Lanoxin in pregnant women. Lanoxin is secreted in breast milk at concentrations similar to concentrations in the mother’s blood. However, the total amount of Lanoxin that will be absorbed from breast milk by the infant may not be enough to cause effects.
What are the important side effects of Lanoxin (digoxin)?
Common side effects include
Many digoxin side effects are dose dependent and happen when blood levels are over the narrow therapeutic range. Therefore, digoxin side effects can be avoided by keeping blood levels within the therapeutic level. Serious side effects associated with digoxin include
- heart block,
- rapid heartbeat, and
- slow heart rate.
Digoxin has also been associated with visual disturbance (blurred or yellow vision), abdominal pain, and breast enlargement. Patients with low blood potassium levels can develop digoxin toxicity even when digoxin levels are not considered elevated. Similarly, high calcium and low magnesium blood levels can increase digoxin toxicity and produce serious disturbances in heart rhythm.
Lanoxin (digoxin) side effects list for healthcare professionals
The following adverse reactions are included in more detail in the Warnings and Precautions section of the label:
- Cardiac arrhythmias
- Digoxin Toxicity
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.
In general, the adverse reactions of Lanoxin are dose-dependent and occur at doses higher than those needed to achieve a therapeutic effect. Hence, adverse reactions are less common when Lanoxin is used within the recommended dose range, is maintained within the therapeutic serum concentration range, and when there is careful attention to concurrent medications and conditions.
In the DIG trial (a trial investigating the effect of digoxin on mortality and morbidity in patients with heart failure), the incidence of hospitalization for suspected digoxin toxicity was 2% in patients taking Lanoxin compared to 0.9% in patients taking placebo.
The overall incidence of adverse reactions with digoxin has been reported as 5-20%, with 15-20% of adverse events considered serious. Cardiac toxicity accounts for about one-half, gastrointestinal disturbances for about one-fourth, and CNS and other toxicity for about one-fourth of these adverse events.
- In addition to nausea and vomiting, the use of digoxin has been associated with abdominal pain, intestinal ischemia, and hemorrhagic necrosis of the intestines.
- Digoxin can cause headache, weakness, dizziness, apathy, confusion, and mental disturbances (such as anxiety, depression, delirium, and hallucination).
What drugs interact with Lanoxin (digoxin)?
- Digoxin has a narrow therapeutic index, increased monitoring of serum digoxin concentrations and for potential signs and symptoms of clinical toxicity is necessary when initiating, adjusting, or discontinuing drugs that may interact with digoxin.
- Prescribers should consult the prescribing information of any drug which is co-prescribed with digoxin for potential drug interaction information.
P-Glycoprotein (PGP) Inducers/Inhibitors
- Digoxin is a substrate of P-glycoprotein, at the level of intestinal absorption, renal tubular section and biliary-intestinal secretion.
- Therefore, drugs that induce/ inhibit P-glycoprotein have the potential to alter digoxin pharmacokinetics.
Pharmacokinetic Drug Interactions
- Pharmacokinetic interactions have been observed and reported primarily when digoxin is coadministered by oral route.
- There are very few studies that have evaluated the drug interaction when digoxin is administered via IV route.
- The magnitude of digoxin exposure change through IV route is generally lower than that through oral route.
- Table below provides available interaction data using digoxin IV formulation (NA means not available).
|Digoxin concentrations increased greater than 50%|
|Digoxin Serum Concentration Increase||Digoxin AUC Increase||Recommendations|
|Quinidine||NA||54-83%||Measure serum digoxin concentrations before initiating concomitant drugs. Reduce digoxin concentrations by decreasing dose by approximately 30-50% or by modifying the dosing frequency and continue monitoring.|
|Digoxin concentrations increased less than 50%|
|Amiodarone||17%||40%||Measure serum digoxin concentrations before initiating concomitant drugs. Reduce digoxin concentrations by decreasing the dose by approximately 15-30% or by modifying the dosing frequency and continue monitoring.|
Potentially Significant Pharmacodynamic Drug Interactions
- Because of considerable variability of pharmacodynamic interactions, the dosage of digoxin should be individualized when patients receive these medications concurrently.
|Drugs that Affect Renal Function||A decline in GFR or tubular secretion, as from ACE inhibitors, angiotensin receptor blockers, nonsteroidal anti-inflammatory drugs [NSAIDs], COX-2 inhibitors may impair the excretion of digoxin.|
|Antiarrthymics||Dofetilide||Concomitant administration with digoxin was associated with a higher rate of torsades de pointes.|
|Sotalol||Proarrhythmic events were more common in patients receiving sotalol and digoxin than on either alone; it is not clear whether this represents an interaction or is related to the presence of CHF, a known risk factor for proarrhythmia, in patients receiving digoxin.|
|Dronedarone||Sudden death was more common in patients receiving digoxin with dronedarone than on either alone; it is not clear whether this represents an interaction or is related to the presence of advanced heart disease, a known risk factor for sudden death in patients receiving digoxin.|
|Parathyroid Hormone Analog||Teriparatide||Sporadic case reports have suggested that hypercalcemia may predispose patients to digitalis toxicity. Teriparatide transiently increases serum calcium.|
|Thyroid supplement||Thyroid||Treatment of hypothyroidism in patients taking digoxin may increase the dose requirements of digoxin.|
|Sympathomimetics||Epinephrine Norepinephrine Dopamine||Can increase the risk of cardiac arrhythmias.|
|Neuromuscular Blocking Agents||Succinylcholine||May cause sudden extrusion of potassium from muscle cells, causing arrhythmias in patients taking digoxin.|
|Supplements||Calcium||If administered rapidly by intravenous route, can produce serious arrhythmias in digitalized patients.|
|Beta-adrenergic blockers and calcium channel blockers||Additive effects on AV node conduction can result in bradycardia and advanced or complete heart block.|
|Ivabradine||Can increase the risk of bradycardia.|
Drug/Laboratory Test Interactions
- Endogenous substances of unknown composition (digoxin-like immunoreactive substances [DLIS]) can interfere with standard radioimmunoassays for digoxin.
- The interference most often causes results to be falsely positive or falsely elevated, but sometimes it causes results to be falsely reduced. Some assays are more subject to these failings than others.
- Several LC/MS/MS methods are available that may provide less susceptibility to DLIS interference.
- DLIS are present in up to half of all neonates and in varying percentages of pregnant women, patients with hypertrophic cardiomyopathy, patients with renal or hepatic dysfunction, and other patients who are volume-expanded for any reason.
- The measured levels of DLIS (as digoxin equivalents) are usually low (0.2-0.4 ng/mL), but sometimes they reach levels that would be considered therapeutic or even toxic.
- In some assays, spironolactone, canrenone, and potassium canrenoate may be falsely detected as digoxin, at levels up to 0.5 ng/mL.
- Some traditional Chinese and Ayurvedic medicine substances like Chan Su, Siberian Ginseng, Asian Ginseng, Ashwagandha, or Dashen can cause similar interference.
- Spironolactone and DLIS are much more extensively protein-bound than digoxin. As a result, assays of free digoxin levels in protein-free ultrafiltrate (which tend to be about 25% less than total levels, consistent with the usual extent of protein binding) are less affected by spironolactone or DLIS.
- It should be noted that ultrafiltration does not solve all interference problems with alternative medicines.
- The use of an LC/MS/MS method may be the better option according to the good results it provides, especially in terms of specificity and limit of quantization.
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Related Disease Conditions
Congestive Heart Failure (CHF)
Congestive heart failure (CHF) refers to a condition in which the heart loses the ability to function properly. Heart disease, high blood pressure, diabetes, myocarditis, and cardiomyopathies are just a few potential causes of congestive heart failure. Signs and symptoms of congestive heart failure may include fatigue, breathlessness, palpitations, angina, and edema. Physical examination, patient history, blood tests, and imaging tests are used to diagnose congestive heart failure. Treatment of heart failure consists of lifestyle modification and taking medications to decrease fluid in the body and ease the strain on the heart. The prognosis of a patient with congestive heart failure depends on the stage of the heart failure and the overall condition of the individual.
What Are the 4 Stages of Congestive Heart Failure?
The New York Heart Association developed the four stages of congestive heart failure depending on the functional capabilities of the heart which includes Class I, Class II, Class III, and Class IV.
Atrial Flutter vs. Atrial Fibrillation
Atrial flutter and atrial fibrillation (AFib) are two types of a heart problem called atrial tachycardia. Both of these conditions involve the heart's electrical activity, but they are not the same disease. Both diseases are serious and need medical treatment. Common symptoms of these diseases are similar and include: Fatigue Blurry vision Lightheadedness Palpitations Feeling like you may faint Serious symptoms of both conditions are similar and include: Fainting Sweating Severe shortness of breath Chest pain Atrial flutter and AFib are heart conditions that require medical diagnosis (ECG) and treatment by a doctor or other medical health-care professional.
Heart failure (congestive) is caused by many conditions including coronary artery disease, heart attack, cardiomyopathy, and conditions that overwork the heart. Symptoms of heart failure include congested lungs, fluid and water retention, dizziness, fatigue and weakness, and rapid or irregular heartbeats. There are two types of congestive heart failure, systolic or left-sided heart failure; and diastolic or right-sided heart failure. Treatment, prognosis, and life-expectancy for a person with congestive heart failure depends upon the stage of the disease.
Atrial Fibrillation (AFib) Treatment Drugs
Atrial fibrillation (AFib) is a heart rhythm disorder that causes irregular and often rapid heartbeat. The medications to treat AFib include beta-blockers, blood thinners, and heart rhythm drugs. Atrial fibrillation drugs can cause serious side effects like seizures, vision changes, shortness of breath, fainting, other abnormal heart rhythms, excessive bleeding while coughing or vomiting, blood in the stool, and bleeding into the brain.
Atrial Fibrillation (AFib)
Atrial fibrillation (AF or AFib) is an abnormality in the heart rhythm, which involves irregular and often rapid beating of the heart. Symptoms may include heart palpitations, dizziness, fainting, fatigue, shortness of breath, and chest pain. Atrial fibrillation treatment may include medication or procedures like cardioversion or ablation to normalize the heart rate.
Atrial Fibrillation vs. Ventricular Fibrillation (AFib vs VFib Symptoms, ECG Strips)
Atrial fibrillation (AF or AFib) is an abnormality in the heart rhythm which involves irregular and often rapid beating of the heart. Symptoms may include heart palpitations, dizziness, fainting, fatigue, shortness of breath, and chest pain. Atrial fibrillation treatment may include medication or procedures like cardioversion or ablation to normalize the heart rate. Atrial fibrillation (AFib) and ventricular fibrillation (VFib) are problems with the heart that cause abnormal heart rhythms. Causes of these heart conditions include, heart disease, drugs and medications, excessive alcohol consumption, high cholesterol, advancing age, a diet that contains high levels of animal meat (fat), high blood pressure, stress, stimulants like caffeine, nicotine. Ventricular fibrillation is the more serious of the conditions because if it isn't treated immediately the person will likely die. Symptoms of AFib are confusion, anxiety, fatigue, a fluttering in the chest, and the feeling that you may pass out or faint. Atrial fibrillation is treated with medications, cardioversion therapy, and surgery. If a person with ventricular fibrillation does not seek medical help immediately they will mostly likely suffer from sudden cardiac arrest or sudden death.
Atrial Fibrillation (AFib) Symptoms and Signs
Atrial fibrillation or AFib is a type of heart rhythm abnormality. Early warning signs and symptoms of atrial fibrillation include chest pain, palpitations, shortness of breath, and lightheadedness. Treatment for atrial fibrillation includes medical procedures, surgery, and medication.
Second Source article from Government
What are the Most Common Causes of Atrial Fibrillation?
Atrial fibrillation (AF) is an abnormal heart rhythm characterized by an irregular and fast heartbeat. The upper chambers of the heart (atria) beat chaotically, and can cause pooling and clotting of blood in the atria, instead of it emptying into the lower chamber (ventricles). AF can lead to stroke, heart failure, blood clots, and heart-related complications. Atrial fibrillation is classified into three types: Paroxysmal atrial fibrillation, persistent atrial fibrillation, and long-standing persistent atrial fibrillation.
What Causes Congestive Heart Failure?
Congestive heart failure is a chronic disease that progresses with time if left untreated. Heart failure can occur due to diseases of the heart, the blood vessels supplying oxygen and nutrients to the heart, or sometimes from factors outside the heart (extracardiac causes). With proper management, people who have congestive heart failure can lead nearly normal lives, depending on the severity of the condition.
What Is the Most Common Cause of Atrial Fibrillation (AFib, AF)?
Atrial fibrillation (AFib or AF) refers to abnormal heart rhythm (arrhythmia) that causes quivering or irregular heartbeats. It is a serious medical condition that may further lead to stroke and heart failure. The heart is a muscular organ roughly the size of a closed fist. It has two upper chambers called atria and two lower chambers called ventricles. The flow of blood into the heart, within the heart chambers, and from the heart is guarded by the four valves present in the heart.
Treatment & Diagnosis
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Medications & Supplements
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Professional side effects and drug interactions sections courtesy of the U.S. Food and Drug Administration.