Experience with labetalol in essential hypertension

A study was carried out in 73 patients with mild or moderate hypertension to assess the effectiveness of treatment with labetalol. After a 2 to 4-week period on placebo, patients received 200 mg labetalol daily for 4 weeks, after which time dosage was doubled if the blood pressure was not satisfactorily controlled. Treatment was continued for a further 4 weeks and was followed by another period on placebo. Pre-treatment levels of 157/99 mmHg were significantly reduced after 2 weeks, and after 4 weeks the mean reduction was 14/8 mmHg. Half the patients had their dosage increased to 400 mg daily. At the end of the 8-week active treatment period, 80% were adequately controlled, the mean reduction in blood pressure being 22/12 mmHg compared with placebo values. Heart rate was significantly reduced from 78 to 69 beats per min during labetalol therapy. The reduction in blood pressure was similar whether or not patients had been previously treated or untreated, but heart rate was reduced more in the previously treated group. Four weeks after the end of labetalol therapy blood pressure and heart rate had increased but were less than during the initial placebo period and did not give rise to any severe problems.