Clinical Evaluation of Practolol, a New Cardioselective Beta-blocking Agent in Angina Pectoris

In a controlled double-blind study practolol, a new cardioselective beta-blocking drug, was given to 15 patients with angina pectoris, and compared with propranolol 80 mg. q.d.s. The dose of practolol ranged from 200 to 600 mg.b.d. and was decided by initial open titration in individual patients. Though practolol did not influence the incidence of angina or glyceryl trinitrate consumption, it increased the duration of exercise possible in exercise tests and reduced the amount of ischaemic S-T depression in the radiocardiogram during exercise. Propranolol reduced the incidence of angina and, in the exercise tests, increased the amount and duration of exercise but did not affect the degree of S-T depression. Unlike propranolol, practolol did not produce any adverse effects on bronchial smooth muscle. Hence it is concluded that practolol is an effective drug in treating angina, and in the dosage used is of potential value in patients with asthmatic bronchitis and angina. It should, however, be used cautiously in anginal patients with heart failure.