Known brand names include Lanoxin and Digox.
A cardiac glycoside that makes the heart pump more strongly and slows the heart rate. It treats mild to moderate heart failure and controls the heart rate in chronic atrial fibrillation. The gap between helpful and toxic levels is narrow.
Digoxin blocks the sodium pump, an enzyme in heart cells that moves sodium out and potassium in. That leaves more calcium inside the heart cells, so the heart muscle squeezes harder. It also slows the heart rate and slows the signal passing through the AV node, the relay between the upper and lower chambers. It lowers the activity of the body's fight-or-flight nerves and of a hormone system that controls blood pressure.
Tablets begin to work within 2 hours, and the full effect comes 2 to 6 hours after a dose. It leaves the body slowly, mostly through the kidneys, so levels build up over days and run higher when the kidneys are weak. Too much of it causes nausea, vomiting, vision changes, and dangerous heart rhythms, and older age, low body weight, weak kidneys, and low potassium make this more likely. Its slowing of the heart's electrical signals explains why it can cause a very slow heartbeat or heart block.
Digoxin is a heart medicine for mild to moderate heart failure, a condition in which the heart does not pump as well as it should. It helps the heart pump more strongly, which improves symptoms and exercise ability and keeps people out of the hospital. It does not help people with heart failure live longer. It also slows a fast heart rate in long-lasting atrial fibrillation, an abnormal rhythm of the heart's upper chambers.
Adults use it for heart failure and atrial fibrillation, and children with heart failure use it to help the heart pump more strongly. For heart failure, it is combined with a water pill (diuretic) and an ACE inhibitor when possible. It is a tablet taken by mouth, and it controls these conditions without curing them. It must not be used in people with ventricular fibrillation, and it is not recommended during a heart attack.
Nausea, vomiting, poor appetite, stomach pain, headache, weakness, dizziness, and confusion are the common complaints, and long-term use can cause breast growth in men. The label treats vision changes, such as blurring, halos, or yellow-green tinted vision, as warning signs. It also warns about dangerous heart rhythms and a very slow heartbeat.