Tobacco and addiction
"Scientists have found that nicotine is as addictive as heroin, cocaine or amphetamines, and for most people, more addictive than alcohol," states the article "Nicotine, Harder to Kick than Heroin," published in the New York Times Magazine.
"Nicotine is similar in all critical measures to prototypic drugs of abuse such as cocaine, morphine and heroin."
"Nicotine is a poison used as an insecticide."
Nicotine is the agent in tobacco that is capable of causing addiction or dependence. Cigarettes have on average, a total nicotine content of about 8.4 milligrams, while many popular brands of cigars will contain between 100 and 200 milligrams of nicotine. When inhaled, nicotine gets to a person's brain in seven seconds, twice as fast as intravenous drugs. Nicotine affects the brain and central nervous system by changing the level of neurotransmitters and chemicals that regulate mood, learning, alertness and ability to concentrate. Nicotine increases the heart rate, but it constricts the blood vessels, thereby reducing circulation. It can act like a stimulant or a sedative, depending on the level of nicotine in the body and time of day. Smoking also causes the release of endorphins, which create a tranquilizing effect. A tolerance for nicotine begins to develop with the first dose. Therefore, the level of use must increase to maintain its effects and to prevent withdrawal symptoms.
Nicotine is a poison and if taken in large doses could kill a person by paralyzing their breathing muscles. Smokers usually take it in small amounts that the body can quickly break down and get rid of, which is why the nicotine in cigarettes does not kill instantly. The first dose of nicotine causes a person to feel awake and alert, while later doses result in a calm, relaxed feeling. Nicotine can make new smokers, and regular smokers who get too much of it, feel dizzy or nauseous. The resting heart rate for young smokers increases 2 to 3 beats per minute. It also lowers skin temperature and reduces blood flow in the legs and feet. Evidence shows that nicotine plays an important role in increasing smokers' risk of heart disease and stroke