Definition of "hyoscyamine" [hy•os•cy•a•mine]

• A poisonous white crystalline alkaloid, C17H23NO3, isometric with atropine and having similar uses but more potent effects. (noun)

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.

• "The chemical constituents of Henbane are "hyoscyamine," a volatile alkaloid, with a bitter principle, "hyoscypricin" (especially just before flowering), also nitrate of potash, which causes the leaves, when burnt, to sparkle with a deflagration, and other inorganic salts."
• "The anti-spasmodic drug that had the best evidence was hyoscyamine (brand names Anaspaz and Levsin)."
• "The anti-spasmodic drug that had the best evidence was hyoscyamine brand names Anaspaz and Levsin."