Ineffectiveness of practolol induced beta-blockade in the treatment of angina pectoris
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A clinical trial of 7 months duration was carried out on 18 patients with angina pectoris. The study was divided in 4 stages: A 4-week single blind stage on placebo, a six-week single blind, dose finding stage divided in 3 periods of 2 weeks each during which the patients received daily doses of 400, 800 and 1,200 mg of practolol respectively. Physician evaluation based on anginal episodes counts, nitroglycerin consumption and exercise stress testing at the end of each dose period were used to select the optimal dose for each patient. Subsequently and after a 2-week single-blind stage on placebo (wash-out) the patients moved to a fourth stage where the optimal dose of practolol was tested against placebo using a double-blind double cross-over design consisting of 4 periods of 4 weeks each. The patients received practolol during two of these periods and placebo during the other two. No difference between practolol and placebo was seen in the frequency of anginal episodes, the nitroglycerin consumption, the blood pressure level and the exercise performance. A significant difference was observed in the resting heart rate and the exercise heart rate. Thus, although the doses used produced beta-blockade they did not lead to objectively demonstrable antianginal effects.
Key wordsPractolol beta-blockers angina
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- Amsterdam, E.A., Gorlin, R., Wolfson, S.: Evaluation of long term use of propranolol in angina pectoris. J. Amer. med. Ass.210, 103–106 (1969)Google Scholar
- Areskog, N.H., Adolfsson, L.: Effects of a cardio-selective beta-adrenergic blocker (ICI 50172) at exercise in angina pectoris. Brit. med. J.1969 II, 601Google Scholar
- Coltart, D.J.: Comparison of effects of propranolol and practolol on exercise tolerance in angina pectoris. Brit. Heart J.33, 62–64 (1971)Google Scholar
- Dunlop, D., Shanks, R.G.: Selective blockade of adrenoceptive beta receptors in the heart. Brit. J. Pharmacol.32, 201–218 (1968)Google Scholar
- Epstein, S.E., Robinson, B.F., Kahler, R.L. et al.: Effect of beta adrenergic blockade on the cardiac response to maximal and submaximal exercise in man. J. clin. Invest.44, 1745–1753 (1965)Google Scholar
- Fitzgerald, J.D., Scales, B.: Effect of a new adrenergic beta blocking agent (ICI 50172) on heart rate in relation to its blood levels. Intern. J. Clin. Pharmacol. Ther. Toxicol.6, 467–474 (1968)Google Scholar
- Gianelly, R.E., Goldman, R.H., Treister, B.: Propranolol in patients with angina pectoris. Ann. Intern. Med.67, 1216–1225 (1967)Google Scholar
- MacAlpin, R.N., Kattus, A.A., Winfield, M.D.: The effect of a β-adrenergic blocking agent (nethalide) and nytroglycerin on exercise tolerance in angina pectoris. Circulation31, 869–875 (1965)Google Scholar
- MacDonald, A.G., McNeil, R.S.: A comparison of the effect on airway resistance of a new beta-blocking drug ICI 50172 and propranolol. Brit. J. Anaesth.40, 508–510 (1968)Google Scholar
- Sandler, G., Clayton, G.A., Thornicroft, S.G.: Clinical evaluation of verapamil in angina pectoris. Brit. med. J.1968 III, 224–227Google Scholar
- Sowton, E., Smithen, C., Leaver, D.: Effect of practolol on exercise tolerance in patients with angina pectoris. Amer. J. Med.51, 63–70 (1971)Google Scholar