Double-blind trial of labetalol.

1 A new anti-hypertensive agent (labetalol) with alpha- and beta-adrenoreceptor-blocking properties has been assessed in 30 patients in a general practice. 2 Significant reduction in blood pressure and pulse rate occurred at a dose of 400 mg/d. A further significant reduction in blood pressure but not of pulse rate occurred at a dose of 800 mg/d. 3 After 4 weeks' treatment on the higher dose the mean fall in systolic and diastolic pressures compared with the pre-trial pressures was 36 and 24 mmHg, respectively. Side-effects were generally mild.