RESUMO
Labetalol, a new antihypertensive drug which combines alpha- and beta-blocking properties, was used in an open clinical trial in a mixed group of 47 adult patients with mainly essential hypertension, many of whom had been poorly controlled on other drugs. Labetalol lowered lying and standing blood pressures significantly when given alone or when combined with other antihypertensive drugs and it was generally well tolerated. It is easy to use, and in some severe cases has been dramatically effective. Mean daily dose was 767 mg. A postural hypotensive effect was seen especially in patients taking concomitant diuretics but was not troublesome. Labetalol reduced heart rate in patients who were not on previous or concomitant beta-blocker therapy. Side effects were few and did not cause major problems. A transiently or persistently weakly positive ANF was noted in nine patients; the significance of this is uncertain at this stage and needs further assessment. Raynaud's phenomenon, which had complicated previous beta-blocker therapy in some patients, improved with labetalol.