Cardiac glycosides are a group of medications derived from plants, primarily used to treat heart conditions, particularly heart failure and atrial fibrillation. They work by increasing the force of the heart's contractions and regulating heart rhythm, which helps improve blood flow and reduce symptoms of heart-related issues. The most well-known cardiac glycoside is digoxin, extracted from the foxglove plant. While effective, these medications require careful dosing due to their narrow therapeutic range, meaning that too much can lead to toxicity. Regular monitoring and consultation with a healthcare provider are essential for safe use.