Nicotine's
mood-altering effects are different by report. First causing a
release of glucose from the liver and epinephrine (adrenaline)
from the adrenal medulla, it causes stimulation. Users report
feelings of relaxation, calmness, and alertness. It is even
reported to produce a mildly euphoric state. By reducing the
appetite and raising the metabolism, some smokers may lose
weight as a consequence. It also allows the mouth to be
stimulated without food, and the taste of tobacco smoke may curb
the appetite.
When a cigarette is smoked, nicotine-rich blood passes from the
lungs to the brain within seven seconds and immediately
stimulates the release of many chemical messengers including
acetylcholine, norepinephrine, epinephrine, vasopressin,
arginine, dopamine, and beta-endorphin. This results in enhanced
pleasure, decreased anxiety, and a state of alert relaxation.
Nicotine enhances concentration, learning, and memory due to the
increase of acetylcholine. It also enhances alertness due to the
increases of acetylcholine and norepinephrine. Arousal is
increased by the increase of norepinephrine. Pain is reduced by
the increases of acetylcholine and beta-endorphin. Anxiety is
reduced by the increase of beta-endorphin. The effects of
nicotine last from five minutes to two hours. Most cigarettes
(in the smoke inhaled) contain 0.1 to 2.8 milligrams of
nicotine.
Research suggests that, when smokers wish to achieve a
stimulating effect, they take short quick puffs, which produce a
low level of blood nicotine. This stimulates nerve transmission.
When they wish to relax, they take deep puffs, which produce a
high level of blood nicotine, which depresses the passage of
nerve impulses, producing a mild sedative effect. At low doses,
Nicotine potently enhances the actions of norepinephrine and
dopamine in the brain, causing a drug effect typical of those of
psychostimulants. At higher doses, nicotine enhances the effect
of serotonin and opiate activity, producing a calming,
pain-killing effect. Nicotine is unique in comparison to most
drugs, as its profile changes from stimulant to sedative/pain
killer in increasing dosages and use.
A 21 mg patch applied to the left armNicotine gum and patches
are available, usually in 2-mg or 4-mg doses of gum, that do not
have all the other ingredients in smoked tobacco. They appear to
be not as addictive or as pleasurable, and, it is claimed, have
fewer side-effects. Whether all the other psychoactive effects
also occur has not been well-studied.
Dependence >>
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Nicotine
History and name
Chemistry
Pharmacology
1.Pharmacokinetics
2.Pharmacodynamics
2.1 In adrenal medulla
2.2 In CNS
Psychoactive effects
Dependence
Toxicology
Therapeutic uses
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