A drug, such as propanolol, that opposes the excitatory effects of norepinephrine released from sympathetic nerve endings at beta-receptors and is used for the treatment of angina, hypertension, arrhythmia, and migraine. Also called beta-adrenergic blocking agent.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.