Lanoxin is a medication that contains the active ingredient digoxin. It is primarily used to treat certain heart conditions, such as heart failure and atrial fibrillation. By increasing the strength of heart contractions and regulating heart rhythm, Lanoxin helps improve blood flow and reduce symptoms associated with these conditions. Lanoxin is usually taken in tablet form or as a liquid. It is important for patients to follow their healthcare provider's instructions regarding dosage and usage. Regular monitoring may be necessary to ensure the medication is effective and to avoid potential side effects, such as nausea or dizziness.