Anti-hypertensive action, time of onset and effects on carbohydrate metabolism of labetalol.

1 Seventeen men, aged 45-57 yr, with essential hypertension showed obvious and, in the standing position, dose-related reductions in blood pressure during treatment with oral labetalol with weekly dose increments. 2 Pulse rate changes were not related to dose but reduced compared with pre-treatment values. 3 No postural hypotension was recorded indicating lack of a dominant alpha-adrenoreceptor-blocking component. 4 There was a small increase in mean fasting blood glucose levels during labetalol treatment but no alteration in insulin activity or response to an oral glucose tolerance test.