Experience with labetalol in hypertension.

1 The effect of labetalol has been assessed in an open clinical trial in 19 patients with sub-optimal control of blood pressure on other therapy, and in a placebo-controlled cross-over study. Most patients were taking a diuretic before the trial and they continued to do so during the trial. 2 In the open trial, labetalol successfully lowered blood pressure in most of the patients. Average daily dose was about 600 mg. The placebo-controlled trial confrimed the anti-hypertensive effect. 3 A clear postural hypotensive effect was seen. A few patients noted postural faintness as a side-effect, especially in a hot environment; but it was not troublesome. 4 There were few other side-effects. One patient experienced an increase in serum glumatic--oxalic transaminase (SGOT) and another an increasing anti-nuclear factor titre, but it is not yet certain that these were due to labetalol.