Labetalol and captopril combined with chlorthalidone in the treatment of mild to moderate essential hypertension

The aim of the study was to compare the antihypertensive activity of labetalol with that of captopril, either alone or in combination with chlorthalidone, in patients suffering from mild to moderate essential hypertension. The trial population consisted of 30 patients with a mean age of 51.6 ± 9 years. The trial was of the simple-blind, randomized type. After a two-week pharmacological washout, the patients were put on placebo treatment for one week, at the end of which those patients with diastolic blood pressure (DBP) in the 95 to 115 mm Hg range were assigned at random to one of the following treatment schedules: Treatment A: labetalol 100 mg b.d. for 2 weeks, at the end of which chlorthalidone 25 mg/die was added, if DBP was still above 95 mm Hg. The labetalol dose was subsequently increased, where necessary, at fortnightly intervals, first to 200 + 100 mg/die and then to 200 mg x 2/die. Treatment B: captopril 25 mg b.d. for 2 weeks, at the end of which, chlorthalidone 25 mg/die was added, if necessary. The captopril dose was subsequently increased at fortnightly intervals in those cases where DBP continued to exceed 95 mm Hg, firstly to 50 mg x 2/die and then to 75 mg x 2/die. The total duration of the trial was 13 weeks, including the placebo week. Twenty-seven patients completed the trial protocol; 2 patients dropped out because of side effects and 1 was discontinued because of poor compliance. On the whole, labetalol showed rapid therapeutic efficacy: 9 patients were found to be normotensive at the 4th week as against 6 patients on treatment B. Over the trial period as a whole, the antihypertensive activities of labetalol and captopril and their use in combination with chlorthalidone proved similar: at the 10th week, all patients in both treatment groups were normotensive. No significant side effects were observed. The results of the trial as a whole indicate that the two drugs may be regarded as valid alternatives in the first-line management of mild to moderate essential hypertension.