Cross-over comparison of the fixed combination of hydrochlorothiazide and triamterene and the free combination of furosemide and triamterene in the maintenance treatment of congestive heart failure

The fixed combination of hydrochlorothiazide 25 mg and triamterene 50 mg and the free combination of furosemide 40 mg and triamterene 50 mg were compared as maintenance treatment in patients who were in a stable condition after an episode of congestive heart failure. All the patients were on digitalis. The trial was of the cross-over design. The treatment order was randomized at each centre. Each treatment lasted for 8 weeks. Of the 37 patients entering the study 30 were suitable for analysis. Both treatments were equally effective in maintaining bodyweight at the same level and in influencing symptoms. The free combination decreased the blood pressure slightly more than the fixed combination, especially the systolic pressure. One-third of the patients were hypertensive at the outset (diastolic pressure greater than 95 mm Hg) and in them the effects of the two treatments were not significantly different. The majority of the patients (80%) preferred treatment with the fixed combination because it caused slower and less frequent micturition.