A drug that opposes the excitatory effects of norepinephrine released from sympathetic nerve endings at alpha-receptors and that causes vasodilation and a decrease in blood pressure. Also called alpha-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.