Nicotine addiction

Nicotine, the active ingredient of tobacco, affects the brain, body and behaviour, including changing heart rate, intestinal action, endocrine functions, brain waves and general arousal. Nicotine effects centrally in the brain producing a mild high that induces craving.

Nicotine is highly addictive. It is both a stimulant and a sedative to the central nervous system. The ingestion of nicotine results in an almost immediate "kick" because it causes a discharge of epinephrine from the adrenal cortex. This stimulates the central nervous system, and other endocrine glands, which causes a sudden release of glucose. Stimulation is then followed by depression and fatigue, leading the abuser to seek more nicotine. Nicotine is absorbed readily from tobacco smoke in the lungs, and it does not matter whether the tobacco smoke is from cigarettes, cigars, or pipes.

A study by researchers at San Francisco General Hospital found that African Americans take in 30% more nicotine with every cigarette as compared with White or Hispanic Americans. Researchers also found that African Americans metabolize cotinine, a nicotine byproduct, more slowly.