Slow-release furosemide and hydrochlorothiazide in congestive cardiac failure: a controlled trial

Thirty-eight ambulatory patients with congestive cardiac failure took part in a double-blind clinical trial of 50 mg hydrochlorothiazide orally daily and slow-release formulation of 60 mg furosemide orally daily. Following a one-week period of placebo administration, patients were randomly allocated to the treatment which they continued for six weeks. Other diuretic drugs were discontinued at entry, but antihypertensive drugs and digoxin were continued during the study at constant dosage. A controlled sodium diet was prescribed. Clinical observations and biochemical and hematologic measurements were made before, during, and at the end of the study. There was an improvement in the clinical condition of patients in both treatment groups, but no significant difference between treatments (with or without digitalis) was detected. Both treatments were clinically well tolerated; however, the tendency of hypokalemia was more pronounced in the hydrochlorothiazide group. This could be hazardous in patients who receive a concomitant cardiac glycoside, especially when no clear-cut benefit of concomitant digitalis therapy is demonstrated.