Labetalol and hydrochlorothiazide in hypertension. Labetalol/Hydrochlorothiazide Multicenter Study Group.
This study was a multicenter, randomized, double-blind, parallel comparison of labetalol vs. placebo added to hydrochlorothiazide (HCTZ) for the treatment of essential hypertension. The study consisted of 2 to 4 weeks of placebo and 3 to 7 weeks of HCTZ, 25 mg twice a day. Both of these first two phases were single blind. Subjects whose standing diastolic blood pressure remained greater than 95 mm Hg while taking HCTZ were randomized to receive either labetalol or matching placebo in addition to the HCTZ. Labetalol was started at 100 mg twice a day; the dose was increased every 2 weeks to a maximum of 400 mg twice a day. Subjects continued taking their maximum tolerated labetalol dose for another 4 weeks during the final phase of the study. Blood pressure fell 10/9 mm Hg supine and 17/13 mm Hg standing after the addition of labetalol (n = 83) and 3/4 and 5/5 mm Hg, respectively, after placebo (n = 91). Labetalol was equally effective in blacks and whites. There was suggestive evidence that women responded better to the combined therapy than did men, and that people greater than 55 years old responded better than those less than 55 years old. Five subjects receiving labetalol and one receiving placebo were dropped from the study because of side effects. Rhinitis was the only adverse effect reported significantly more often with labetalol than with placebo. We conclude that labetalol is a safe and effective step II antihypertensive for patients with moderate to moderately severe hypertension that does not respond adequately to HCTZ alone.
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000375:Aging; D000704:Analysis of Variance; D001794:Blood Pressure / Q000187:drug effects; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D004983:Ethanolamines / Q000627:therapeutic use*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006852:Hydrochlorothiazide / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006973:Hypertension / Q000188:drug therapy*; D007741:Labetalol / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011187:Posture; D011897:Random Allocation
D004983:Ethanolamines; D006852:Hydrochlorothiazide; D007741:Labetalol