Maintenance of potassium balance during diuretic therapy.

The relative efficacies of potassium chloride, amiloride, triamterene and spironolactone in maintaining potassium balance were studied in 40 patients with essential hypertension receiving diuretic therapy. The preparations were administered in random order in a cross-over manner. In 31 patients treated with 50 mg hydrochlorothiazide daily, addition of 1500 mg potassium chloride daily was the weakest and 50 mg spironolactone daily the most effective agent for maintaining serum potassium. Amiloride (5 mg daily) and triamterene (75 mg daily) were less effective and equally so. Similar results were obtained with 9 patients treated with double dosages of the diuretic and supplements. Despite changes in serum potassium, total body potassium remained constant throughout the trial.