Comparison of two doses of betaxolol and placebo in hypertension: a randomized, double-blind cross-over trial.
Betaxolol is a cardioselective beta-blocker, which has a bioavailability of 90% and a T 1/2 of 20 h. A four group, cross-over double-blind trial was conducted to select between betaxolol 20 mg and 40 mg for long term trials. 60 patients were allocated randomly to one of the sequences placebo-20 mg, 20 mg-placebo, placebo-40 mg and 40 mg-placebo, each treatment lasting for 2 weeks. Groups were homogenous for baseline diastolic blood pressure (DBP), age and male/female ratio, and were slightly unbalanced for weight. A two-way ANOVA (3 treatments, 2 sequences) showed no treatment-sequence interaction nor sequence effect. The mean reduction in DBP was 14.2 +/- 1.8 mm Hg following 20 mg and 18.0 +/- 1.8 following 40 mg betaxolol, and 4.0 +/- 1.2 mm Hg during placebo (p less than 0.001). Age, weight, baseline DBP and duration of hypertension did not influence the treatment effect. The 95% confidence intervals of the reduction in DBP were 10.4 - 17.9 for 20 mg and 14.3 - 21.6 mm Hg for betaxolol 40 mg. Aiming at a mean reduction to 90 mm Hg, betaxolol 20 mg would appear to be adequate in similar patient populations.
D015784:Betaxolol; D001794:Blood Pressure / Q000187:drug effects; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D004341:Drug Evaluation; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010919:Placebos; D011412:Propanolamines / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D011897:Random Allocation
D010919:Placebos; D011412:Propanolamines; D015784:Betaxolol