[ thee-uh-fil-een, -in ]
/ ˌθi əˈfɪl in, -ɪn /

noun Pharmacology.

a white, crystalline, poisonous alkaloid, C7H8N4O2, an isomer of theobromine, extracted from tea leaves or produced synthetically: used to relieve bronchial spasms, in the treatment of certain heart conditions, and as a diuretic.

Origin of theophylline

1890–95; theo-, irregular combining form representing New Latin thea tea + -phyll + -ine2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for theophylline

  • Caffeine, theophylline, and theobromine are not found in animal tissues, but are fairly widely distributed in plants.

    The Chemistry of Plant Life|Roscoe Wilfred Thatcher

British Dictionary definitions for theophylline


/ (ˌθɪəˈfɪliːn, -ɪn, θɪˈɒfɪlɪn) /


a white crystalline slightly water-soluble alkaloid that is an isomer of theobromine: it occurs in plants, such as tea, and is used to treat asthma. Formula: C 7 H 8 N 4 O 2See also xanthine (def. 2)

Word Origin for theophylline

C19: from theo (bromine) + phyllo- + -ine ²
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for theophylline


[ thē-ŏfə-lĭn, thē′ō-fĭlēn′ ]


A colorless crystalline alkaloid derived from tea leaves or made synthetically, used as a cardiac stimulant and diuretic.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for theophylline


[ thē-ŏfə-lĭn ]

A colorless, crystalline alkaloid derived from tea leaves or made synthetically. It is used in medicine especially as a bronchial dilator. Theophylline is a xanthine that is similar in structure to caffeine and is a structural isomer of theobromine. Chemical formula: C7H8N4O2.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.