Comparison of low doses of hydrochlorothiazide plus amiloride and hydrochlorothiazide alone in hypertension in elderly patients.

A randomised, double-blind study comparing 25 mg of hydrochlorothiazide plus 2.5 mg of amiloride with 25 mg of hydrochlorothiazide alone was conducted in 40 elderly patients with mild to moderate hypertension. After 8 weeks of treatment, the target blood pressure, supine diastolic blood pressure less than 90 mm Hg, was obtained in 73% of the hydrochlorothiazide plus amiloride treated patients (n = 17) and in 41% of the hydrochlorothiazide treated patients (n = 19; p less than 0.05). However, there was no statistically significant difference in blood pressure reduction between the 2 groups. Four patients dropped out, 3 of them due to side-effects. Serum potassium and magnesium concentrations were reduced in the hydrochlorothiazide group and serum sodium concentration in the hydrochlorothiazide plus amiloride group. Our results suggest that in elderly hypertensive subjects, a higher proportion of patients could be managed with the low dose hydrochlorothiazide plus amiloride regimen than with the low dose hydrochlorothiazide regimen.