Efficacy of Betaxolol in the Treatment of Stable Exertional Angina Pectoris: A Dose-Ranging Study

Abstract

To assess the efficacy of oral betaxolol in the treatment of stable exertional angina pectoris and to determine the relationship between betaxolol doses/serum concentrations and clinical/hemodynamic responses the authors studied 24 patients prior to and following stepwise administration of 5, 10, 20, 40, and 80 mg doses. The major endpoint for the study was the achievement of clinical beta blockade (heart rate 50-60 beats/min and ≤ 20% rise in treadmill stage I heart rate). Betaxolol produced a decrease in mean angina pectoris frequency from 6.6 ± 1.9 episodes/week with placebo to 0.2 ± 0.5 episode/week during clinical beta blockade (p < 0.00005). Mean treadmill exercise time increased from 3.1 ± 1.7 min with placebo to 7.3 ± 2.3 min with doses sufficient to reduce angina pectoris frequency ≥ 75% (p < 0.00005) and to 8.0 ± 2.3 min during clinical beta blockade (p < 0.00005). The mean doses of betaxolol required to produce a ≥ 75% decrease in angina pectoris frequency and clinical beta blockade were 12 ± 5 mg (range 5-40 mg) and 28 ± 29 mg (range 5-80 mg) respectively. Mean serum concentrations associated with these clinical endpoints were 23.8 ± 9.7 ng/mL and 59.7 ± 54.0 ng/mL respectively. The results indicate that betaxolol, in widely ranging doses, is highly effective in reducing angina pectoris frequency and improving exercise capacity in patients with stable exertional angina pectoris.