Hypertension in the elderly: a study of a combination of atenolol, hydrochlorothiazide and amiloride hydrochloride.

The anti-hypertensive effects of atenolol (Tenormin) 50 mg, a potassium-sparing diuretic (half-strength Moduretic) comprising hydrochlorothiazide 25 mg plus 2.5 mg amiloride hydrochloride, and the 'free' combination of atenolol and diuretic were compared in elderly hypertensive patients aged 60-79 years. After a four-week run-in period on placebo, patients were randomly assigned, in a double-blind manner, to atenolol or diuretic treatment, each for four weeks. Thereafter patients were given the 'free' combination for a further four weeks and this treatment was continued for six months. Blood pressure and heart rate were measured after the patient had rested for five minutes supine and after two minutes standing. These blood pressure measurements were made at least 24 hours after the preceding dose using a Random Zero sphygmomanometer. Results from 26 of the 27 patients entered into the study showed an advantage for combination therapy combined with either atenolol or diuretic treatment alone. No significant difference was found between treatments in the frequency of supraventricular and ventricular ectopic beats occurring in six patients who underwent 24-hour ambulatory ECG monitoring. However, ectopic activity was reduced in some patients during beta-blocker treatment. Few adverse effects occurred with any treatment. Three patients withdrew during the placebo period and three withdrew while taking active treatment. This study has shown that the combination of atenolol, hydrochlorothiazide and amiloride hydrochloride is an effective, safe, well-tolerated antihypertensive drug regimen when used once daily in elderly hypertensive patients.