Isolated systolic hypertension in the elderly. A placebo-controlled, dose-response evaluation of chlorthalidone.

One hundred seventy-one patients, 60 years of age or older with isolated systolic hypertension, were randomly assigned to receive chlorthalidone 12.5, 25.0, or 50.0 mg or placebo once daily for 12 weeks. The majority of the patients receiving chlorthalidone 12.5 mg achieved therapeutic success with no clinically significant biochemical changes or side effects. The 50.0-mg dose level enhanced efficacy only minimally over the 25.0-mg dose level. Drug-related side effects were significantly more prevalent in the chlorthalidone 50.0-mg group than in the placebo group. The data suggest that most elderly patients with isolated systolic hypertension, regardless of the severity, could be treated effectively and safely with chlorthalidone 12.5 mg per day.