Bisoprolol vs. chlorthalidone: a randomized, double-blind, comparative study in arterial hypertension

The antihypertensive effect and tolerance of bisoprolol and chlorthalidone were evaluated in a randomized, double-blind, controlled trial during 4 weeks of treatment. A total of46 patients, aged 18-65 years, were initially included; 41 patients presenting with a diastolic blood pressure between 95 and 120 mm Hg at the end of a previous placebo period completed the trial. They were randomly allocated to two groups: 22 patients were treated with bisoprolol 10 mg o.d., and 19 patients with chlorthalidone 50 mg o.d. Both treatments induced a significant reduction in systolic and diastolic blood pressure (p < 0.001). No difference in antihypertensive efficacy was found between the two treatments after 4 weeks. However, with chlorthalidone, significant changes were found with regard to serum potassium (decrease; p < 0.001) and uric acid (increase: p < 0.05) and the incidence of clinical side effects was higher in the chlorthalidone group (37%) in comparison to the patients treated with bisoprolol (13%).