20 patients (12 female) with moderately severe essential hypertension [blood pressure during placebo treatment 181 +/- 6 (systolic), 107 +/- 3 (diastolic)] completed a double-blind, cross-over dose-titrated comparison of labetalol and methyldopa. Both drugs reduced lying and standing arterial blood pressure to a similar extent, although only labetalol reduced heart rate. Compliance was high (greater than 95%) with both drugs, and the incidence of subjective adverse effects was similar.

1 Twenty patients with essential hypertension completed a double-blind, dose-tritrated, cross-over comparison of methyldopa and labetalol. 2 Average lying BPs (systolic/diastolic) were reduced by 28/15 mmHg with methyldopa and by 23/15 mmHg with labetalol. 3 Average standing BPs (systolic/diastolic) were reduced by 29/14 mmHg with methyldopa and by 29/15 mmHg with labetalol. 4 Both lying and standing heart rates were reduced with labetalol. 5 It is concluded that the antihypertensive properties of labetalol and methyldopa are similar but that larger patient populations are needed to study the relative incidence of subjective adverse effects.

1 In a multicentre open trial, labetalol was given to 128 patients in ten centres. Forty-three patients had not previously received antihypertensive therapy; the remainder (85 patients) had been on antihypertensive therapy with either unsatisfactory BP control or troublesome side-effects. 2 Thirty-two patients were withdrawn from the trial in the first 6 months of therapy, 24 (19% of the total) because of side-effects. 3 Control of BP was generally satisfactory or considerably improved. Other drugs (usually a diuretic) had to be added in 23 patients. 4 There was an abnormality of liver function in one patient; otherwise there were no biochemical or haematological problems.