Effect of Propranolol (Inderal) in Angina Pectoris: Preliminary Report

Abstract

The effect of a new beta-adrenergic blocking agent propranolol (Inderal) in 20 patients with angina pectoris was studied by comparing exercise tolerance on a bicycle ergometer before and after intravenous injection of the drug. The parenteral dose needed to produce satisfactory blockade, as judged by bradycardia, was about one-tenth of that required in the case of pronethalol. No side-effects were noted after intravenous injection. The exercise tolerance of the seven patients who were limited by angina pectoris was generally increased after the drug (group A). Five patients limited by angina in the control test had no angina at a similar work level after the drug (group B). Seven patients were limited by fatigue and showed no change in exercise tolerance (group C). This study suggests that beta-adrenergic blockade may be helpful in angina pectoris. Further work is needed to assess the mechanism of improvement in exercise tolerance and to determine the effectiveness of prolonged oral therapy. © 1964, British Medical Journal Publishing Group. All rights reserved.