theophylline
noun
the·oph·yl·line
thē-ˈä-fə-lən 
: a feebly basic bitter crystalline compound C7H8N4O2 present in tea leaves that is isomeric with theobromine and is used in medicine especially as a bronchodilator
Examples of theophylline in a Sentence
Recent Examples on the Web
After caffeine is absorbed into the bloodstream, the liver breaks it into three different kinds of compounds: theobromine, theophylline, and paraxanthine, said Liz Daniels, DO, RD, FAAP, a registered dietitian and private practice doctor who hosts the Nutrition for the Early Years podcast.
—
Currie Engel, Health, 21 May 2026
Milder stimulants such as theophylline, found in cocoa, and theobromine, found in tea, are often included as well, Coyle said.
—Cnn.com Wire Service, Mercury News, 10 Dec. 2025
The genetic circuit was programmed to respond to a harmless chemical, called theophylline, commonly found in caffeine, tea and chocolate.
—Discover Magazine, 11 Nov. 2023
Tea also contains two other types of methylxanthines, theophylline and theobromine, which are both considered to be muscle relaxants, Richardson says.
—Adele Jackson-Gibson, Good Housekeeping, 1 Nov. 2022
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Currie Engel, Health, 21 May 2026
Milder stimulants such as theophylline, found in cocoa, and theobromine, found in tea, are often included as well, Coyle said.
—Cnn.com Wire Service, Mercury News, 10 Dec. 2025
The genetic circuit was programmed to respond to a harmless chemical, called theophylline, commonly found in caffeine, tea and chocolate.
—Discover Magazine, 11 Nov. 2023
Tea also contains two other types of methylxanthines, theophylline and theobromine, which are both considered to be muscle relaxants, Richardson says.
—Adele Jackson-Gibson, Good Housekeeping, 1 Nov. 2022
Cite this Entry
“Theophylline.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/theophylline. Accessed 16 Jun. 2026.
Copy CitationMedical Definition
theophylline
noun
the·oph·yl·line
thē-ˈäf-ə-lən
: a feebly basic bitter crystalline compound C7H8N4O2 that is present in small amounts in tea but is prepared chiefly by synthesis, that is isomeric with theobromine, and that is used in medicine often in the form of derivatives or in combination with other drugs especially as a bronchodilator to relieve or prevent symptoms of asthma and bronchospasm associated with chronic bronchitis and emphysema
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