Digitalis intoxication in geriatric in-patients. A prospective clinical study of the value of serum digitalis concentration measurement.

A prospective clinical study of 66 geriatric in-patients mainly on digoxin treatment revealed digitalis intoxication in seven (11%). Over a two-month period another patient developed digoxin toxicity. The prevalences of anorexia, nausea and vomiting were significantly higher in patients with than without digitalis toxicity. The mean serum drug concentration was significantly higher in overdosed than in non-overdosed patients, but six patients had serum digoxin concentrations within or below the therapeutic range, and only two slightly above. Notably, maintenance digoxin therapy was unnecessary in five out of eight intoxicated patients. The value of determining serum digitalis concentrations in diagnosing clinical toxicity in geriatric in-patients is discussed.