Comparison of slow-release pindolol, standard pindolol, and propranolol in angina pectoris.

Twenty-two patients with chronic, stable, exercise-induced angina pectoris were assessed during periods of therapy with propranolol, standard-formulation pindolol, and a slow-release preparation of pindolol. Patients maintained diaries of the frequency of angina pectoris and nitroglycerin consumption and underwent treadmill exercise testing at 2 weekly intervals. No significant differences were observed in nitroglycerin consumption or anginal frequency during these 3 treatment programs. Resting heart rates were higher with pindolol than with propranolol, but no differences were noted between periods on standard and slow-release pindolol. Systolic and diastolic blood pressures were similar during therapy with these 3 treatment programs. Treadmill walking time to the development of moderate angina and systolic and diastolic blood pressure was similar during treatment with propranolol, standard-formulation pindolol, and slow-release pindolol. Exercise heart rates were slightly higher during therapy with slow-release pindolol than during standard-formulation pindolol. It is concluded that propranolol, pindolol, and slow-release pindolol are equally effective in the management of patients with chronic, stable, exercise-induced angina.