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Nicotine
Nicotine, which is a stimulant drug, is one of the leading
causes of death in the United States. The Food and Drug
Administration (FDA) declared nicotine a drug on July 12,
1996, despite increasing protests by tobacco companies.
Of all deaths in the United States, 20% can be attributed
to the effects of smoking.
Types
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Cigarettes
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Cigars
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Pipes
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Chewing tobacco
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Methods of Use
Tobacco can be smoked in a rolled cigarette or cigar or in a pipe. It can also be chewed.
Effects on the Central Nervous System
Nicotine is a stimulant that has a very rapid effect on the central nervous system.
It can reach the brain within 8 seconds of smoking a cigarette. Structurally, nicotine
resembles a naturally occurring chemical messenger in the brain:
a neurotransmitter called
acetylcholine. Acetylcholine governs many essential body functions such as heart rate,
circulation, learning, and memory. Because nicotine is so similar to acetylcholine, it
is able to mimic acetylcholine actions in the brain, leading to stimulating effects on
all of those body functions. At the same time, nicotine stimulates increases in another
neurotransmitter called dopamine,
which stimulates the dopamine receptors in the brain's pleasure center to create a feeling of pleasure or euphoria.
Nicotine Intoxication
Nicotine intoxication generally happens quickly because smoking is a highly effective
delivery process. Nicotine goes straight to the lungs, where it is absorbed by the blood,
sent to the heart, and pumped into the arteries and brain. Its effects on the body may include:
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Muscle twitching
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Weakness
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Rapid breathing
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Rapid heartbeat
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Abdominal cramps
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Elevated blood pressure
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Confusion, agitation
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Depression
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Life Risks
About 45% of all smokers will die of a tobacco-related health problem
(Petro, Lopez, Boreham, Thun, and Heath, 1992). Nicotine use has decreased
among adult Americans, but it has been increasing among teenagers and
children. Nicotine is an addictive drug that can cause tolerance,
dependence, and symptoms
of withdrawal.
The tars in tobacco, not the nicotine, cause the cancers that frequently develop
in the lungs, throat, and other organs of chronic smokers. Cigarette smoke
contains carbon monoxide, which prevents oxygen from attaching to red blood
cells that carry it through the body. Chronic smoking causes carbon
monoxide poisoning, which can damage the heart and brain.
Withdrawal
Physical withdrawal symptoms include irregular heartbeat, digestive problems,
irregular body temperature, and intense cravings. Psychological symptoms include
irritability, anxiety, and sleep disturbance. Cravings for nicotine can last for
days, weeks, or years after a person stops smoking.
References
Peto R, Lopez AD, Boreham J, Thun M, Heath C Jr: Mortality from tobacco in
developed countries: indirect estimation from national vital statistics.
Lancet 1992; 339:1268-1278.
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