Metabolic studies on patients with resistant heart failure treated by spironolactone.

Metabolic balance studies were carried out on five patients with resistant heart failure treated with spironolactone and other diuretics. Spironolactone alone had little effect. When it was used in a daily dose of 400-600 mg. in combination with hydrochlorothiazide 100 mg. daily, the results were excellent in two patients. One of these was still free of failure after 12 months on combined therapy. In the other patient the serum potassium became elevated after a good diuresis, though on subsequent intermittent therapy with the drug the patient remained well for 12 months. In two other patients administration of spironolactone had to be discontinued because of elevation of the serum potassium before a good diuresis could take place. The fifth patient died.Spironolactone can be a useful adjunct to the therapy of resistant heart failure, but there appears to be a real danger of causing the serum potassium to rise to toxic levels in patients so treated.