Caffeine is a naturally occurring xanthine derivative. Other xanthine derivatives include the bronchodilator theophylline and theobromine, a compound found in cocoa and chocolate.
Caffeine is found in many beverages and soft drinks.
Clinically, it is used parenterally as a respiratory stimulant in neonates. It also is sold without a prescription in products marketed to treat drowsiness. Caffeine was first approved by the FDA for use in a drug product in 1938. Caffeine is a mild, direct stimulant at all levels of the CNS and also stimulates the heart and cardiovascular system. The related xanthine, theophylline, shares these properties and is widely used in the treatment of pulmonary disease.