Dose-dependent effects of betaxolol in hypertension: a double-blind, multicenter study

This study determined the dose-response relationship among three doses of betaxolol compared with placebo in patients with mild-to-moderate hypertension. In this double-blind, placebo-controlled trial, 317 hypertensive patients were randomly assigned to receive placebo or betaxolol 5, 10, or 20 mg once daily for 4 weeks. A significant (P less than .05) decrease in supine diastolic blood pressure (BP) compared with concurrent placebo was evident with all three doses of betaxolol after 1 week of active treatment. Each dose of betaxolol maintained a significant reduction in diastolic and systolic BP and heart rate responses throughout the 4-week treatment period. At the fourth week (final treatment evaluation), BP and heart rate were significantly (P less than .05) reduced by all three doses of betaxolol compared with placebo. For supine systolic and diastolic BP, the decreases with betaxolol 20 mg were significantly (P less than .05) greater than with the 5 mg dose, but there was no statistically significant difference between the 10-mg and either the 5- or 20-mg doses. For standing diastolic BP, the effect of betaxolol 5 mg once daily was significantly (P less than .05) less than that of 10 and 20 mg. The overall supine diastolic BP response to betaxolol was dose dependent, and more patients responded to the 10- and 20-mg doses of betaxolol (66% and 76%, respectively) than to the 5-mg dose (59%). For each efficacy variable, the absolute magnitude of the reduction was greater with increasing dose. In subgroup analyses, BP responses were analyzed by race, age, baseline BP, and age combined with baseline BP.(ABSTRACT TRUNCATED AT 250 WORDS)