A single-blind, comparative study of hydrochlorothiazide/amiloride ('Moduret' 25) and hydrochlorothiazide/triamterene ('dyazide') in elderly patients with congestive heart failure.

The efficacy and biochemical effects of two low-dose thiazide plus potassium-sparing diuretic preparations were compared in the treatment of elderly patients with stable, mild to moderate congestive heart failure. Sixty patients (mean age 80 years) were randomly allocated to treatment with 1 tablet daily of either 25 mg hydrochlorothiazide/2.5 mg amiloride or 25 mg hydrochlorothiazide/50 mg triamterene. The dose was increased to 2 tablets daily if necessary, after 2 weeks, for a further 6 weeks. Patients' response to treatment was assessed at 2, 4 and 8 weeks using a simple clinical scoring system for signs and symptoms of their condition, and routine biochemical analysis was carried out at baseline and the end of treatment. One patient was withdrawn from the study due to a rash which was probably related to hydrochlorothiazide/amiloride treatment. A further 11 patients were excluded from the analysis because of intercurrent illness or inadequate records. Analysis of the results from 48 patients showed that both treatments resulted in an improvement in clinical score and weight reduction, with more than three-quarters of the patients responding to treatment. No serious biochemical disturbances occurred; in particular, no new cases of hyponatraemia (serum sodium less than 130 mmol/l) developed. Both preparations, therefore, were effective and tolerated forms of treatment for mild to moderate congestive heart failure in the elderly and there were no significant differences between them.