Caffeine refers to an alkaloid found in coffee, cocoa beans, tea, kola nuts and guarana. Also added to many fizzy drinks, energy drinks, pep pills and cold and flu remedies. A stimulant of the central nervous system. Pure caffeine is a moderately powerful drug and is sometimes passed off as amphetamine. In small doses, such as the 150 milligrams in a typical cup of filter coffee, it increases alertness and promotes wakefulness. Caffeine also raises heart and respiration rate and promotes urine production. Higher doses induce jitteriness and anxiety. The fatal dose is about 10 grams. It raises heart and respiration rate and promotes urine production
