The properties of beta-adrenoceptor antagonists.

After the clinical studies with pronethalol and propranolol confirmed Black's hypothesis that drugs which block beta-adrenoceptors were of value in the treatment of patients with angina pectoris and cardiac arrhythmias, other compounds have been described which block beta-adrenoceptors. Detailed pharmacological studies with propranolol and comparison of its properties with those of other beta-adrenoceptor blocking drugs have indicated that these drugs may possess properties in addition to their effect in blocking beta-adrenoceptors. These properties have been termed intrinsic sympathomimetic activity, membrane stabilizing activity and cardioselectivity. These properties have all been described in detailed observations in laboratory animals but not to the same extent in normal man or in patients. It appears that the therapeutic effectiveness of these drugs results from their beta-adrenoceptor blocking activity and that intrinsic sympathomimetic activity and membrane stabilizing activity do not contribute to the effects of these drugs in patients, although cardioselectivity may be of value in some patients.