Dynamics of propranolol dosing schedules

Kinetic and dynamic data from 27 healthy male subjects were evaluated in a double-blind, randomized, double-crossover study to test the hypothesis that 180 mg/day propranolol twice and three times a day would provide much the same plasma levels and beta 1-blockade. The data indicate that propranolol twice rather than three times a day should be favored when beta 1-blockade is needed in therapy. The dynamic efficacy of the two schedules was the same and maximum concentration, AUC0-24, and 0-hr plasma propranolol values were higher after twice-than after three-times-daily dosing. The degree of beta 1-blockade (reduction in exercise tachycardia) was much the same on both dosing regimens at trough concentrations. These data indicate that both twice- and three-times-a-day dosing schedules provide well-sustained 24-hr beta-blockade and are probably interchangeable for therapeutic purposes.