A pilot trial of labetalol (AH 5158A): a combined alpha and beta blocker in treatment of hypertension.

Labetalol (5-1 hydroxy-2 (1-methyl-3 phenyl amino salicylamide hydrochloride)) is a new antihypertensive agent having partial alpha- and beta-adrenoreceptor-blocking properties. Nine patients with mild, moderate or severe hypertension have been given this drug over periods ranging from 6-29 weeks. Labetalol was given as replacement for a beta-blocking drug providing less than satisfactory control. Adequate control of blood pressure was achieved in all nine patients. The only side-effect of note was postural hypotension which necessitated withdrawal of the drug in one patient.