Atenolol and chlorthalidone therapy for hypertension: a double-blind comparison.

In a randomized, double-blind, parallel-group study of 31 patients with mild to moderate hypertension, we compared a placebo regimen with a regimen of atenolol and chlorthalidone (Tenoretic). The study, which lasted seven weeks, began with a single-blind two-week placebo lead-in period, followed by a four-week double-blind treatment phase, and concluded with a one-week single-blind placebo washout period. Of 24 patients included in the analysis of efficacy, seven received one Tenoretic 50 tablet per day (atenolol, 50 mg; chlorthalidone, 25 mg), nine received one Tenoretic 100 tablet per day (atenolol, 100 mg; chlorthalidone, 25 mg), and eight received placebo. Supine systolic/diastolic blood pressure (mean +/- SD) decreased from 154 +/- 15.2/102 +/- 4.6 mm Hg during the baseline period to 128 +/- 8.5/85 +/- 4.0 mm Hg during treatment in the group receiving Tenoretic 100, from 153 +/- 12.6/104 +/- 5.4 mm Hg to 137 +/- 4.5/91 +/- 4.4 mm Hg in the group receiving Tenoretic 50, and from 150 +/- 11.9/101 +/- 1.6 mm Hg to 145 +/- 11.6/93 +/- 5.1 mm Hg in the group receiving placebo. Reductions in systolic and diastolic blood pressures in the active treatment groups were significantly greater than the pressure reductions in the group receiving placebo (P less than .05 to .1). The combination of atenolol and chlorthalidone was well tolerated, and in no case was treatment discontinued because of side effects. This study showed that one tablet per day of either Tenoretic 50 or Tenoretic 100 is effective and well tolerated in the treatment of mild to moderate hypertension.