Nicotine is a clear to pale yellow liquid that is naturally found in tobacco plants, tomato plants, and other plants in the Nightshade family. It was named after Jean Nicot, the French ambassador to Portugal in the 1560s. Nicot wrote and spoke much of the medicinal qualities of the plant following the discovery of its use among the tribes of North and Central America by early Western explorers.
Just like cocaine and heroin, nicotine is an addicting drug. When taken in small amounts, as in many tobacco products, it produces "pleasurable" feelings. It is absorbed through the lungs, the mucous membranes (the lining of nose and mouth) and the skin so may be smoked, chewed or applied in patches. Chewing tobacco must have flavorings added to make it attractive as tobacco tastes terrible. The most common and quickest way to get nicotine into the bloodstream is by smoking it. The lungs are lined by millions of tiny air sacs where the nicotine enters with the air and smoke inhaled. These air sacs have an enormous surface area - 90 times greater than that of the skin - and so the nicotine quickly passes into the blood. It reaches the brain about ten to fifteen seconds from the time it was inhaled.
Nicotine is an extremely toxic substance and is considered more additive than heroin. 20-100 mg of nicotine causes death depending on the size of the person or animal. Cigarettes contain 9-30 mg of nicotine depending on the type of cigarette; while a cigarette butt contains about 25% of the nicotine of the original cigarette despite its deceptively small amount of tobacco. Cigars can contain up to 40 mg. Chewing tobacco carries 6-8 mg per gram while the gum is 2-4 mg per piece and patches 8.3-114 mg. Smoking a cigarette yields only 0.5-2 mg of nicotine but eating one is another story as all of the nicotine becomes available for absorption into the body in the small intestine. However, one of the first things nicotine does in the body is to stimulate the vomit centre of the brain, which may save the patientís life if there is more cigarette material in the stomach. Nicotine is also sold commercially in the form of a pesticide - it kills things!
Nicotine affects the chemistry of the brain. It stimulates the release of a chemical messenger in the brain. This messenger is responsible for feelings of pleasure and temporarily increases mental alertness. This is why nicotine is put in the category of drugs called stimulants. A stimulant is a drug that produces a short-lived increase in the body's activity. The human brain reacts the same way to nicotine as it does to cocaine and heroin. They all cause "highs" to occur in the person using them. However a tolerance to these effects develops rapidly. Tolerance means that a smoker will need more and more of the drug to reach the same "high". Addiction may begin with someone's first experience with nicotine. People become dependent on the drug and suffer both physical and emotional withdrawal symptoms if they stop using it. Irritability occurs when a person tries to quit. Nicotine doesn't stay in the body for too long, lasting only 40 minutes to a couple of hours. This means that to maintain a steady level of nicotine in the body a person keeps smoking cigarettes throughout the day increasing the addiction.
As well as these effects, nicotine keeps bad company. For those who smoke, a mixture of chemicals enters the body in addition to nicotine and these cause serious damage to the body. Cigarette smoke includes tar and 4,000 other chemicals, including 43 substances that cause cancer. Others include gases, such as carbon monoxide. Carbon monoxide interferes with the blood's ability to carry oxygen to the body's tissues. (See Poster)