Caffeine, a central nervous system stimulant, is an out-of-favor treatment for overdose of alcohol and narcotic pain relievers. It is currently used to treat neonatal apnea. Caffeine is also widely used in "over-the-counter" beverages to relieve drowsiness and fatigue. Caffeine works by targeting and stimulating the areas of the brain that control breathing and other basic functions. The term "alkaloid" refers to the fact that it is a naturally occurring chemical compound containing numerous nitrogen molecules. Caffeine is isolated fron the coffee bean.