Definitions

trimethylxanthine

caffeine

[ka-feen, kaf-een, kaf-ee-in]

Heterocyclic compound that, like other alkaloids, has marked physiological effects. It occurs in coffee beans, tea leaves, kola nuts, cacao, maté, and guarana and in the products made from them. Its stimulating effect on the central nervous system, heart, cardiovascular system, and kidneys makes it medically useful in treating respiratory depression caused by overdose of barbiturates, morphine, or heroin. Its positive effects can include improved motor performance, decreased fatigue, increased alertness, and enhanced sensory activity. Excessive caffeine can produce irritability, anxiety, insomnia, and potentially serious symptoms such as heart irregularities and delirium. Much of the caffeine included in many over-the-counter stimulants, cold remedies, and painkillers has been extracted during production of decaffeinated coffee and tea.

Learn more about caffeine with a free trial on Britannica.com.

See Caffeine
Search another word or see trimethylxanthineon Dictionary | Thesaurus |Spanish
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature