Combinations of diuretics and vasopressin antagonists are useful to slow and reverse the symptoms and process of congestive heart failure, to increase the excretion of water in the urine, and to decrease the excretion of sodium and potassium ions in urine. Preferred vasopressin antagonists have the formula ##STR00001## wherein R and R.sup.5 are hydrogen or lower alkyl; R.sup.1, R.sup.2, and R.sup.3 are hydrogen, halo, alkyl, alkoxy, and amino; and R.sup.4 is hydrogen or phenyl, and a pharmaceutically acceptable salt thereof.