Normal doses of calcium supplements are generally safe to take unless there is a coexisting problem such as calcium containing kidney stones or high levels of calcium in the blood associated with certain hormonal abnormalities or cancer . Digoxin has been used for many years in the treatment of heart failure . It increases the force of contraction generated by the heart thereby increasing cardiac output. It does this indirectly by increasing the amount of calcium in the heart available to the contractile machinery of muscle. By increasing the cardiac output, there is decreased central activity via the sympathetic nervous system, thereby decreasing the heart rate and returning urine formation to normal.
Digoxin also depresses the electrical activity of the heart.
It is sometimes used to slow the heart rate in patients with certain abnormal heart rhythms . However, too much digoxin can slow the heart too much or cause other arrhythmias. People receiving digoxin often have their blood potassium levels checked because low levels can increase the risk of digoxin toxicity. Diuretics are drugs that increase production of urine and thereby reduce the amount of fluid in the body. They generally act by increasing the amount of sodium eliminated in the urine.