Treatment of severe hypertension with labetalol compared with methyldopa and furosemide. Results of a long-term, double-blind, multicenter trial.

Eighty-one severely hypertensive patients were enrolled in a multicenter, double-blind, parallel group study evaluating the efficacy and safety of labetalol alone or in combination with furosemide versus methyldopa in combination with furosemide. A one day to four week placebo lead-in phase was followed by a one- to six-week titration period and a one-year maintenance period. Treatment with labetalol alone or in combination with furosemide, as well as methyldopa plus furosemide, was associated with significant reductions in supine and standing blood pressure levels. Moreover, after six months and one year of treatment, respectively, labetalol caused a significantly (p less than 0.05) greater reduction in the systolic blood pressure than the methyldopa regimen. The antihypertensive effect of labetalol was associated with small, yet significant reductions in heart rate; in contrast, resting tachycardia was observed in methyldopa-treated patients. Side effect profiles of the two treatments were different, with nausea being the most commonly reported side effect during labetalol therapy, and asthenia, somnolence, and dry mouth during methyldopa therapy. Overall, 33 of 65 (53 percent) labetalol-treated and 28 of 60 (47 percent) methyldopa-treated patients had at least a good response (that is, standing diastolic blood pressure 90 to 94 mm Hg) to therapy, including 26 (40 percent) and 22 (37 percent) patients, respectively, who had standing diastolic blood pressure levels of less than 90 mm Hg. Thus, labetalol is a potentially safe and effective agent in the long-term management of the patient with severe hypertension.