Nicotine is a nitrogen-containing chemical - an alkaloid, which is made by several types of plants, including the tobacco plant. Nicotine is also produced synthetically.
Nicotiana tabacum, the type of nicotine found in tobacco plants, comes from the nightshade family. Red peppers, eggplant, tomatoes and potatoes are examples of the nightshade family.
Apart from being a substance found in tobacco products, nicotine is also an antiherbivore chemical, specifically for the elimination of insects - it used to be extensively used as an insecticide.
MediLexicon's medical dictionary definition of nicotine:
Nicotine is "A poisonous volatile alkaloid derived from tobacco (Nicotiana spp.) and responsible for many of the effects of tobacco; it first stimulates (small doses), then depresses (large doses) at autonomic ganglia and myoneural junctions. Its principal urinary metabolite is cotinine.
Nicotine is an important tool in physiologic and pharmacologic investigation, is used as an insecticide and fumigant, and forms salts with most acids."
Nicotine's molecular formula is C10H14N2.
Contents of this article:
You will also see introductions at the end of some sections to any recent developments that have been covered by MNT's news stories. Also look out for links to information about related conditions.
Here are some key points about nicotine. More detail and supporting information is in the main article.
- Nicotine is named after a 16th Century French ambassador.
- Nicotine was first synthesized in 1904.
- Chewing or snorting tobacco products usually releases more nicotine into the body than smoking.
- Nicotine is at least as difficult to give up as heroin.
- The side effects of nicotine can affect the heart, hormones and the gastrointestinal system.
- Nicotine acts as both a sedative and a stimulant.
- Some studies suggest that nicotine may improve memory and concentration.
- There are more than one billion tobacco smokers worldwide.
History of nicotine
Nicotiana tabacum, the type of nicotine found in tobacco plants, comes from the nightshade family
The French ambassador in Portugal, Jean Nicot de Villemain, sent tobacco and seeds to Paris from Brazil in 1560, saying that tobacco had medicinal uses. From his name came the Latin name for the tobacco plant - Nicotianana tabacum.
Nicot sent snuff - powdered tobacco that is sniffed through the nostril - to Catherine de Medici, the Queen of France at the time. He said it would treat her migraines. Nicot, who suffered from headaches, said the snuff helped relieve symptoms. The Queen tried it and said it was effective. She said that tobacco should be called the Herba Regina (the herb of the queen).
In 1828, Wilhelm Heinrich Posselt, a doctor, and Karl Ludwig Reinmann, a chemist, both from Germany, first isolated nicotine from the tobacco plant. They said it was a poison.
Louise Melsens, a Belgian chemist and physicist, described nicotine's empirical formula in 1843, and Adolf Pinner and Richard Wolffenstein, both chemists from Germany, described its structure in 1893.
In 1904, nicotine was first synthesized by A. Pictet and P. Crepieux.
Effects of nicotine
Pharmacologic effects of nicotine
When humans, mammals and most other types of animals are exposed to nicotine, it increases their heart rate, heart muscle oxygen consumption rate, and heart stroke volume - these are known as pharmacologic effects.
Psychodynamic effects of nicotine
The consumption of nicotine is also linked to raised alertness, euphoria, and a sensation of being relaxed.
Pharmacokinetics of nicotine
Pharmacokinetics refers to what the body does to a substance, while pharmacodynamics refers to what a substance does to the body.
After inhaling tobacco smoke, nicotine rapidly enters the bloodstream, crosses the blood-brain barrier and is inside the brain within eight to twenty seconds. Within approximately two hours after entering the body, half of the nicotine has gone (elimination half-life of about two hours).
How much nicotine may enter a smoker's body depends on:
- What type of tobacco is being used
- Whether or not the smoker inhales the smoke
- Whether a filter is used, and what type of filter it is.
Tobacco products that are chewed, placed inside the mouth, or snorted tend to release considerably larger amounts of nicotine into the body than smoking.
Nicotine is broken down (metabolized) in the liver, mostly by cytochrome P450 enzymes. Cotinine is the main metabolite.
Nicotine is one of the most difficult substances to quit once addicted.
Nicotine is highly addictive. People who regularly consume nicotine and then suddenly stop experience withdrawal symptoms, which may include cravings, a sense of emptiness, anxiety, depression, moodiness, irritability, and inattentiveness. The American Heart Association says that nicotine (from smoking tobacco) is one of the hardest substances to quit - at least as hard as heroin.
According to a report published by the Massachusetts Department of Public Health, tobacco companies steadily increased the nicotine content of their cigarettes from 1998 to 2004, by approximately 10%. The higher the nicotine dose in each cigarette, the harder it is for the regular smoker to quit.
The Department accused the tobacco companies of deliberately making their customers more addicted, so that they could secure sales. Doctors complain that this business strategy of getting customers more hooked undermines the success rates of smoking cessation therapies.
In November 2012, tobacco companies were ordered by US District Judge Gladys Kessler to inform consumers that they had deliberately manipulated their cigarettes so that smokers would become more addicted.
A study carried out at the National Institute on Drug Abuse found that nicotine consumption makes cocaine more addictive.
Side effects of nicotine
The most common side effects of nicotine are featured in this graphic:
The 'nicotine effect'
Nicotine is both a sedative and a stimulant. When our bodies are exposed to nicotine, we experience a "kick"- this is partly caused by nicotine's stimulation of the adrenal glands, resulting in the release of adrenaline (apinephrine). This surge of adrenaline stimulates the body, there is an immediate release of glucose, as well as an increase in heart rate, respiration and blood pressure.
Nicotine also makes the pancreas produce less insulin, resulting in slight hyperglycemia (high blood sugar or glucose).
Indirectly, nicotine causes dopamine to be released in the pleasure and motivation areas of the brain. A similar effect occurs when people take heroin or cocaine. The drug user experiences pleasure.
As users become more tolerant to nicotine, they require higher doses in order to enjoy the same effects.
Dopamine is a brain chemical that affects emotions, movements, and sensations of pleasure and pain. Dopamine neurotransmitters are located in the substantia nigra, deep in the middle of the brain. Put simply, if your brain dopamine levels rise, your sensation of contentment is higher.
Depending on the nicotine dose taken and the individual's nervous system arousal, nicotine can also act as a sedative.
The more nicotine we have, the higher our tolerance becomes, and we require higher doses to enjoy the same initial effects. As most of the nicotine in the body is gone during sleep, tolerance may have virtually disappeared first thing in the morning. That is why many smokers say their first cigarette of the day is the best, or strongest. As the day develops, nicotine has less of an effect, because of tolerance build-up.
Concentration and memory
Studies have shown that nicotine appears to improve memory and concentration. Experts say that this is due to an increase in acetylcholine and norepinephrine. Norepinephrine also increases the sensation of wakefulness (arousal).
Nicotine results in increased levels of beta-endorphin, which reduces anxiety.
Nicotine and smoking
Humans get their nicotine "fix" primarily through smoking tobacco, but can also obtain it by snorting snuff, chewing tobacco, or taking NRTs (nicotine replacement therapies), such as nicotine gum, lozenges, patches and inhalators.
By far, the most popular way of consuming nicotine is by smoking cigarettes. Worldwide, over one billion people are regular tobacco smokers, according to WHO (World Health Organization).
Smoking in the USA - Approximately 23% of adult males and 18% of adult females in the USA are smokers. Over 400,000 thousand premature deaths in the country are caused by cigarette companies, nearly 20% of all deaths. More people die as a result of smoking than all the deaths due to HIV, vehicle accidents, murders, suicides, alcohol abuse and drug abuse combined.
Smoking in the UK - approximately 24% of the UK adult population are smokers, according to the NHS (National Health Service) - 25% of males and 23% of females. 114,000 smokers die prematurely in the UK every year.
The NHS, UK, says that about 70% of all British smokers would like to quit, but believe they cannot. Half of all smokers in the country eventually manage to give up successfully.
Cigarette smoking originates from the European exploration and colonization of the Americas, where tobacco was common. Smoking tobacco soon became popular in Europe, and then spread to the rest of the world.
Increased anxiety is common during nicotine withdrawal. After discovering the brain circuitry responsible, scientists suggest ways people trying to quit may avoid the side effect.
It was previously thought drug addiction results from two separate brain systems, but a study suggests neurons in the reward system are active during both use and withdrawal.
Research suggests a reason many alcohol drinkers are also smokers is because nicotine suppresses the sleep-inducing effects of alcohol via a wake-promoting brain region.