Nicotine is an addictive substance found in the smoke from cigarettes, cigars, and pipes and in smokeless tobacco products such as chewing tobacco and snuff. Nicotine addiction is characterized by compulsive drug-seeking and use even in the face of significant medical disease consequences.

Nicotine is the most widely abused addictive substance available. Approximately 57 million Americans smoke and another 7 million use smokeless tobacco. Tobacco kills more than 400,000 people a year in the United States and contributes to an estimated $80 billion of U.S. health care costs related to coronary heart disease, lung cancer, asthma, and cancers of the mouth, pharynx, larynx, esophagus, stomach, pancreas, cervix, kidney, ureter and bladder.

Chronic use of nicotine leads to neurological changes in the brain that result in addiction. Symptoms include tolerance, a condition in which higher doses of the drug are needed to produce a similar amount of stimulation. Attempts to quit often lead to withdrawal symptoms that may last as long as a month or more. These symptoms include irritability, craving, mental deficits, and sleep disturbances. Cravings for nicotine after quitting can last for 6 months or longer.

For smokers who are motivated to quit, pharmacological and behavioral treatments can be effective. Nicotine replacement therapies such as nicotine gum, the transdermal patch, nasal spray and inhaler are used to reduce withdrawal symptoms. Bupropion, a non-nicotine prescription antidepressant, has also been effective in reducing withdrawal and increasing the chances of successful quitting. The most effective treatments combine these pharmacotherapies with behavior therapy aimed at breaking the habit of nicotine use.