Once daily administration of sustained release propranolol capsules in the treatment of angina pectoris

Abstract

The effect of once daily administration of sustained release capsules of propranolol 160 mg was compared with treatment with standard 40 mg tablets four times daily, in eight patients with stable angina pectoris, in a four week, double blind crossover, random treatment-order trial. Clinical evaluation and submaximal bicycle ergometry were performed before propranolol therapy and on the last day of each treatment period. Serum propranolol concentration over a 24 hour period on those two days ranged from 34.4 to 65.5 ng/ml for the tablets, and 27.7–76.0 ng/ml for the capsules. The peak increase in heart rate on exercise fell from 59 beats per minute to 43 and 41 bpm following the tablets and capsules, respectively (p<0.05). The degree of ST segment depression decreased from 1.94 mm to 0.94 mm and 0.63 mm, respectively (p<0.05). Serum propranolol concentrations were significantly correlated with the reduction in peak heart rate (r=0.58, p<0.05), and in heart rate-pressure product (r=0.83, p<0.01). Clinical attacks and nitroglycerin requirements were equally reduced by both formulations. Sustained release capsules of propranolol 160 mg given once daily were as effective as standard 40 mg tablets given four times daily in the treatment of stable angina pectoris in patients requiring this dose range.