The effect of labetalol in the treatment of severe drug-resistant hypertension.

Twenty-two hypertensive patients from a large clinic, who were resistant to conventional therapy, were entered into this study. Most patients previously had received beta-blocking drugs, thiazide diuretics, alpha-methyl-dopa, or vasodilator drugs (hydrallazine or prazosin) which failed to control their blood pressure. The therapy with vasodilator drugs was discontinued, and the therapy with labetalol (a drug with both alpha-blocking and beta-blocking effect) was commenced. Subsequently, as the blood pressure came under control, other drugs that the patients were taking were also withdrawn. In 13 of the 22 patients, labetalol enabled the blood pressure to be controlled at acceptable levels. In six patients, the response was not considered to be sufficient to justify continuation of labetalol therapy. In three patients, the drug was withdrawn because of postural hypotension in one patient, intractable diarrhoea in another, and an allergic-type skin rash in the third. In certain patients, postural changes in blood pressure were observed, but this rarely produced symptoms. It is suggested that, if blood pressure control is not achieved with a thiazide diuretic and a beta-blocking drug, then labetalol should be introduced and the beta-blocking drug should be withdrawn.