Nicotine is a highly toxic drug, with only 60 mg being lethal to an adult. The average cigarette contains 8 to 9 mg of nicotine; so one pack of cigarettes contains enough nicotine to kill the average adult, to say nothing of a child. Depending on smoking technique, a smoker receives about 1 mg of nicotine per cigarette. The effects of nicotine are complex but are similar to acetylcholine poisoning. Acute effects of nicotine poisoning include nausea, vomiting, salivation, diarrhea, dizziness, mental confusion, and weakness. At high levels of exposure, nicotine causes decreased blood pressure, difficulty breathing, irregular pulse, convulsions, respiratory failure, and death.

Nicotine is probably the most addictive drug readily available to the average person. The nicotinic effects from smoking are highly reinforcing, with some users comparing the effects to cocaine or amphetamine. Regular smokers consume nicotine for stimulation but also to avoid the withdrawal effects. The withdrawal effects include irritability, anxiety, restlessness, impatience, increased appetite and weight gain. Nicotine patches take advantage of nicotine's ability to cross the skin barrier and are used to maintain a steady state blood level of nicotine and thus reduce the desire to smoke. Nicotine gum and now nicotine drinks are often used as an alternative to smoking.

Nicotine also affects the developing fetus. Adverse effects of chronic nicotine consumption during pregnancy include reduced infant birth weight, attention deficit disorders, and other cognitive problems. Nicotine receptors are expressed early during development, and it is not clear what effects nicotine exposure during development has on the fetus.

The health effects of nicotine cannot be entirely separated from the effects of cigarettes as a whole. Nicotine keeps people smoking, but the many other compounds found in cigarettes that are inhaled when smoking contribute to respiratory disease, cardiovascular disease, and lung cancer. The carcinogenic properties of nicotine alone have yet to be evaluated independent of tobacco smoke.

Regulation

Concerns over the hazards of secondhand smoke are now widely accepted, which has resulted in increased restrictions on indoor smoking. Some US states have laws limiting smoking outdoors near doorways and more recently have even limited smoking in cars when children are present.

On March 21, 2000, the U.S. Supreme Court ruled that the U.S. Food and Drug Administration did not have the authority to regulate tobacco. On June 22, 2009, President Obama signed the Family Smoking Prevention and Tobacco Control Act, landmark legislation that gives the U.S. Food and Drug Administration authority to regulate the manufacturing and marketing of tobacco. Details on the Act are available here: http://www.govtrack.us/congress/bill.xpd?bill=h111-1256&tab=summary.

Next: Recommendation and Conclusions