Best Practice Guide: Nicotine & Health

Best Practice Guide: Nicotine & Health Oliver Norman

Best Practice Guide: Nicotine & Health

Nicotine has been a part of human culture for what is estimated to be over 2000 years. It Originates from the plant “Nicotiana Tabacum” or as we all know it, tobacco. The substance has been used as both a medicine and stimulant by different cultures for almost as long as history has been recorded.

Despite its long history with us, nicotine has a number of profound effects on the human body and mind. While some are considered positive, the impacts of nicotine consumption have been the subject of increasing scrutiny as our understanding of them has progressed.

In the present day the most common forms of nicotine consumption, like smoking, are widely understood to carry a broad variety of negative health impacts. While it is true that the majority of the harm that can come from regular smoking is directly linked to the other harmful chemicals in cigarette smoke, the nicotine is what keeps us coming back for more.

Whether you are a smoker or vaper, it is important to understand the nature of the substance that keeps us tied to our habits, and how it might be impacting your mental and physical health. Join us as we explore what nicotine really is, why it is so addictive, and the effects its consumption can have on not only our bodies, but our minds.

A Brief History of Nicotine

Consumption of the tobacco plant has been prolific in human cultures for a long time, first being utilised by indigenous tribes as a part of medicinal ritual ceremonies. The tobacco plant itself is native to the Americas. While it is not known exactly how it reached European shores, it is believed to have been brought back by Christopher Columbus, who settled in Portugal for a time in the 1400s following his famous first expedition to the “New World”.

Both the plant Nicotiana tabacum, and the compound nicotine itself are named for Jean Nicot. He was a French ambassador to Portugal who, in 1550, sent tobacco seeds to Paris for cultivation. A crude form of nicotine was known to scientists by 1571.

Smoking culture rapidly took western society by storm, with pipe and cigar smoking spreading rapidly through the 1600s. The tobacco industry was established and growing by the 1700s with more and more people taking up the habit. Not only popular for smoking, tobacco was also used as an insecticide by 1763.

In 1828, nicotine was first isolated from the tobacco plant in its purest form by Dr William Heinrich Posselt, and chemist Karl Ludwig Reinmann. These German scientists were the first to identify nicotine as a poison. Despite this discovery, the invention of the first patented machine for mass-production of paper cigarettes caused tobacco consumption to explode in 1880.

It wasn’t until these later stages of the 19th century that lawmakers began to recognise the harmful effects of nicotine, banning tobacco sale to minors in 26 US states by 1890. However, it wasn’t until as recently as 1964 that the US surgeon general published a study linking smoking with heart disease and lung cancer. With the US Food and Drug Administration (FDA) only officially recognising nicotine’s addictive properties by 1994.

In the modern age, nicotine is available to the public in a wide variety of forms. Smoking the tobacco leaf remains the most commonly used method of nicotine consumption, but it can also be delivered by Nicotine Replacement Therapies like patches and gums, not to mention vaping products. We understand more about the harm nicotine and smoking can cause now than at any point in history, yet the addictive nature of nicotine itself is likely why smoking remains one of the leading global causes of preventable death.

The only known use of nicotine besides human consumption is as a pesticide, however it has declined in use since World War Two and has even been banned in recent years due to the potential harm it poses to mammals (like humans!) in high concentrations.

The Science of Nicotine

Nicotine is the highly addictive compound found naturally within the tobacco plant. Nicotine represents around 5% of any given tobacco plant’s total weight. Despite only making up such a small part of the plant material we smoke, it is nicotine that keeps people smoking even when they might want to quit.

What is Nicotine?

Nicotine is an organic compound and belongs to a group of substances called alkaloids. Alkaloids are compounds which contain nitrogen, that are known to have marked physiological effects on humans.

In fact, nicotine has been classified as a stimulant, much like caffeine or cocaine. Stimulants excite bodily functions but in particular the brain and central nervous system. They are known to induce alertness, elevated mood, wakefulness, increased motor activity and a decrease in appetite – all effects synonymous with smoking.

How is Nicotine Absorbed?

When tobacco is smoked, a nicotine patch is applied, or gum chewed, the nicotine passes through your body’s biological membranes. These membranes are in your mouth and lungs primarily, however in the case of patches the nicotine absorbs dermally (through the skin), ultimately ending up in your bloodstream. From here it is delivered to various parts of the body, but it is particularly well-absorbed by the brain, taking only around 10-20 seconds to reach it after taking a puff on a cigarette.

How well nicotine is absorbed by a person can depend on a surprising number of factors beyond just the delivery method. Race, gender, and age have all been observed to impact absorption rates and metabolism. People of African descent for example were observed to clear nicotine levels slower than those of white ethnicity, meaning it remains in their system longer. People of Chinese descent were also recorded to absorb less nicotine per cigarette than those of Latin or White descent. Indeed, it has even been observed that women metabolise nicotine faster than men.

Nicotine Addiction

It is widely understood in the 21st Century that nicotine is a highly addictive substance. In fact, it is one of the most addictive substances known to man, being scientifically accepted as harder to overcome than heroin in many cases.

As a stimulant, nicotine is a part of the family of drugs considered to be among the most habit-forming. Delivering short-term benefits to a person’s mood and sense of wellbeing, while simultaneously creating conditions to the contrary; a person may smoke to relieve stress, without realising the withdrawal effects of nicotine are actually driving them to smoke in the first place.

There have been a massive number of studies carried out investigating the addictive nature of nicotine, with scientists constantly amazed by how powerful it can be. One researcher, Dr Daniel McGehee, stated that “it would be difficult to design a better drug than nicotine to promote addiction”.

Why is Nicotine So Addictive?

The National Institute for Drug Abuse (NIDA) funded research at the University of Chicago, which found that a major part of nicotine’s addictiveness lies in its double action upon the brain. It directly stimulates the feelings of pleasure in the brain, while indirectly prevents those feelings from lasting very long or coming on very strong.

In this way nicotine toys with your brains reward system, causing you to crave the satisfaction of a cigarette for example, while chemically ensuring the joy will be short-lived, leading you to consume more and more in pursuit of a dwindling pleasure.

Once it reaches your brain, nicotine binds to special neurons and causes them to produce the neurotransmitter Dopamine. Dopamine is not only responsible for feelings of pleasure, but also drives our desire to repeat behaviours that led to that pleasure.

For example, drinking water when thirsty is a universal example of this action-reward relationship. When we drink to quench our thirst, our brains are flooded with dopamine which gives us satisfaction and reinforces that this was the correct response to our situation, making us want to do it again if the same circumstances arise.

Nicotine takes this relationship to the next level, which is why it is so powerfully addictive. NIDA discovered that dopamine levels triggered by nicotine remain high even after the direct stimulus (smoking, for example) ends. This means that the desire to repeat behaviour like smoking is even stronger than natural causes like drinking water.

This occurs because of the way nicotine interacts with two other neurotransmitters in your brain: glutamate and GABA. Glutamate speeds up the activity of your brain’s neurons, whereas GABA slows them down.

Researchers discovered that nicotine specifically causes glutamate to massively speed up the release of dopamine, while at the same time preventing GABA from slowing it down naturally. This results in a dopamine hit that can last over an hour, and results in an immensely powerful desire to repeat the behaviour that led to such a boost – an addiction.

Summarising the findings, Dr McGehee said:

"A brief application of nicotine can induce a lasting effect on excitatory [glutamate] signals to the brain's reward system."

"This suggests that in humans a relatively short nicotine exposure, even for someone who has never smoked before, can cause long-lasting changes in excitatory neurotransmission.”

"The combination of effects - increasing dopamine release and decreasing the inhibitory [GABA] response - results in an amplification of the rewarding properties of nicotine, it would be difficult to design a better drug to promote addiction."

Nicotine Damage and Withdrawal

Nicotine has a profound effect on the brain and body, with prolonged exposure at different points in our development having varied consequences. The power of the dependence caused by nicotine addiction alone means that those attempting to leave it behind can expect to face a number of different withdrawal symptoms both physical and mental in nature.

Physical Impact

Because nicotine acts on so many parts of the body, it can cause widespread damage if consumed regularly and in large amounts. NIH research has found prolonged exposure can damage the heart, kidneys, liver and beyond. Despite the current findings however, research is still ongoing to establish the true risks associated with Nicotine. Studies observing NRT use in patients who were smokers with heart disease found that, when stopping tobacco use completely and using only NRT, the risks of death or hospitalisation were greatly reduced in all patients.

It was also found to reduce a person’s natural immune response and increase their risk of respiratory and cardiovascular disorders, let alone the negative impacts on reproductive health. Worse still, a significant number of studies also linked nicotine to cancer, which is unsurprising given the known risks of smoking – however the majority of this risk comes from the additional chemicals in cigarette smoke, rather than nicotine by itself.

Nicotine when isolated and in the quantities most people would normally consume is actually a well-tolerated substance. While links to cancer exist, they are not well substantiated. Modern experts theorise that Nicotine is no more likely to cause cancer than caffeine. Studies in human trials have struggled to prove that nicotine (exclusively) causes increased risk of cancer. It is believed the delivery method and the additional chemicals consumed while using them carries the greater risk, such as those in cigarettes and to a lesser extent, vaping.

While NRT’s only deliver small amounts of nicotine even they can pose a risk, with tobacco posing the greatest risk of not only physical harm but of forming addiction. Long-term use can lead to any number of the above issues developing. Even in the slightest cases, nicotine withdrawal can lead to headaches and fatigue.

Studies have shown that nicotine use increases the heart rate from 10-15 beats per minute, and can slightly elevate blood pressure. It has been shown to have diuretic effects on the body, meaning you are more likely to be dehydrated while using it.

Physical Withdrawal Symptoms


Within a day or so of your last cigarette, your appetite will shoot up for a while. Nicotine binds to receptors in the brain which release dopamine and serotonin. These two chemicals reduce hunger, so when they’re out of your system you’ll want to eat more. A lot of people also find that they eat to fill the time they used to spend smoking. Most people gain about 5 to 10 pounds as they try to quit smoking.


Nicotine cravings are the symptom you will deal with the longest, and they could start just 30 minutes after your last cigarette. An average craving will last only about 15 to 20 minutes, but they are persistent.

Headaches and dizziness:

These are usually mild and are often the first withdrawal symptom to show up and taper off.


Nicotine is a stimulant, so you’ll probably feel tired without it. You may also be restless and might have insomnia.


For the first month of abstaining from nicotine, constipation can be another unpleasant side effect.

Mental Impact

Nicotine addiction has a prolific impact on a person’s mental health. The most obvious symptoms of withdrawal include irritability and increased anxiety when cravings reach their peak. This can have negative effects upon not only your wellbeing and ability to cope with daily life, but also your relationships with those around you.

The majority of smokers pick up the habit during adolescence, with 70% reporting to have smoked a cigarette at least once according to the National Institute for Health (NIH). During this time, the prefrontal cortex is still developing.

This is the area of the brain responsible for executive functions and attention performance, and it is particularly susceptible to damage from nicotine consumption. The risk of developing psychiatric disorders and mental health issues later in life has been observed to greatly increase if the person was a smoker in their adolescence.

Mental Withdrawal Symptoms


The nicotine delivered when smoking is widely perceived to relieve stress, when quitting this can cause your anxiety to skyrocket as you are defying your brains desire to repeat the behaviour that gave you such a powerful chemical reward.


For the same reasons as anxiety above, suddenly removing nicotine from your life can lead to feelings of depression. While these are generally gone within a month, those with a history of medical anxiety and depression may require extra support.


As a result of the physical symptoms of withdrawal, it is common for a person to have a very short fuse. This can cause you to become angry at the slightest thing, however this is normal and should pass with time.

Mental Fog:

As the nicotine slowly leaves your body, many people have expressed a difficulty concentrating and remaining focussed on everyday tasks.

Timeline of Addiction

Nicotine withdrawal physically lasts for around a month. However, you could be fighting a mental battle against the temptation of a cigarette for a very long time, if not for life. The important thing to remember is that withdrawal impact everyone differently, your GP is the best person to advise you of the appropriate support to overcome your own addiction.

The first week of a quit attempt is considered the most challenging, particularly days three through 5. This is the point at which the nicotine should have finally left your body, triggering powerful cravings leading to headaches and even insomnia.

Most relapses occur within the first two weeks of quitting, and it is believed that if a person can outlast this then the physical symptoms will recede to a manageable level. This will still leave you to deal with mental issues like anxiety, irritability and even depression, however these too should recede after a matter of weeks.

A person's ability to overcome nicotine addiction will always depend on the individual’s mindset and willpower, as well as ensuring they have access to the correct guidance and support.

30 minutes to 4 hours:

The initial effects from the nicotine will wear off and you’ll start to crave another cigarette.

10 hours:

You will be very restless, physically craving a cigarette, and wondering how to fill the time. You may feel sad and hopeless.

24 hours:

Irritability will kick in and your appetite will increase.

2 days:

You’ll likely have headaches as the nicotine leaves your system.

3 days:

The nicotine should be gone from your system at this point. Your cravings should taper off but anxiety may start to rise.

1 week:

Pat yourself on the back, you've made it through the worst. Avoiding triggers is vital to avoid relapse.

2 to 4 weeks:

You still won’t have much energy, but any mental fog should be clearing and your appetite will settle down. Your cough, depression, and anxiety should also improve.

5 weeks on:

With most physical symptoms behind you, the key is now remaining strong mentally.

Nicotine and Mental Health

Mental health has been given an increasingly large share of the medical spotlight in recent years. There are now more networks of support and guidance available to those suffering from a myriad of conditions than ever before.

Our collective understanding of mental health disorders and how to treat them has increased massively in the 21st Century, and we now know far more about the relationships between our lifestyle choices and our mental wellbeing.

Nicotine and smoking often go hand-in-hand, and the two have undeniable links to mental health. Despite the common belief that smoking helps you to relax, relieve stress and settle anxiety, experts including the NHS have proven the contrary. In fact, smoking is understood to increase tension and anxiety, with smokers also being more likely to develop depression than non-smokers.

There is a clear link between smoking and mental health, with those suffering from a long-term condition smoking far more than those without.

Nicotine and Stress

It’s a mean trick nicotine can play on our minds – the craving for a cigarette makes us feel stressed irritable and anxious. These feelings are then temporarily relieved when we smoke, giving us the impression that smoking has improved our mood and reduced our stress levels.

In reality, the need to relieve this stress would largely not exist if we did not have an addiction to nicotine in the first place – a self-fulfilling prophecy. Worse still, while smoking reduces the withdrawal symptoms, it cannot actually reduce anxiety or deal with the root cause of the issue - It’s a sticking plaster on a gunshot wound.

Nicotine and Depression

Adults suffering from depression are twice as likely to smoke as those without. Because the withdrawal symptoms of nicotine addiction are synonymous with depression, it is still not completely understood whether smoking leads to depression or vice-versa, the relationship is complex.

Those with depression often have lower levels of dopamine in their system. Smoking is an easy way for these people to experience a temporary boost of dopamine by consuming nicotine. While this may seem positive at first, over time the act of smoking encourages the brain’s natural dopamine trigger to switch-off, decreasing an already low supply even more and ultimately exacerbating the feeling of depression.

Those with depression may be hit particularly hard by withdrawal during a quit attempt. If you smoked before experiencing depression, and after abstaining from nicotine for two weeks or more do not feel your mood has improved, then the cause of the depression may lie elsewhere and you should consult your GP for advice.

Those suffering with depression while quitting nicotine are advised to follow the below advice to help them on their journey:


Being physically active can help. Start small and build up over time. This can be hard to do when you’re depressed. But your efforts will pay off.

Structure your day:

Make a plan to stay busy. Get out of the house if you can.

Be with other people:

Many people who are depressed are cut off from other people. Being in touch or talking with others every day can help your mood.

Reward yourself:

Do things you enjoy. Even small things add up and help you feel better.

Nicotine and Anxiety

One of the most prevalent mental health issues faced by modern society is anxiety. While we all experience it in some form throughout our daily lives, particularly extreme circumstances and those who are susceptible to it can experience far more intense bouts that can cripple them and prevent them leading a normal life.

Because of smoking’s perceived ability to boost mood, many anxiety sufferers take up the habit in an effort to manage their emotions. The unfortunate reality is that doing so can not only trigger anxiety, but intensify it.

The feeling of relief experienced in these cases is not actually because of any effect on your anxiety, but simply because smoking reduces the withdrawal symptoms of nicotine addiction – the impact is temporary and ultimately does not resolve the original reason you were anxious in the first place, meaning the feelings will almost always return. When combined with the anxiety triggered by nicotine withdrawal alone, you may end up facing twice as much nervousness, fear and panic.

Practicing the below relaxation techniques can help to manage anxiety without the dependence on nicotine, but you should always consult your GP for proper advice tailored to your needs.


Take a few slow, deep breaths—in through your nose, out through your mouth.

Locate Your Stress:

Explore where stress affects your body. Finding ways to reduce physical tension will also help your mental stress. A warm bath, a massage, or stretching can help.


Think of a place where you feel safe, comfortable, and relaxed. Picture it as clearly as you can, including imagining what you would feel, hear, and maybe even smell if you were in that relaxing place.


Life can sometimes be overwhelming. try to focus on what is happening now, not what you might have to deal with in the future.


Make an extra effort to take care of yourself. This includes basic things like eating a balanced diet, drinking lots of water, and getting enough sleep.

Do Good:

Doing something nice for others can make your day better too. Being caring toward others helps reduce your own stress.


Caffeine can help you stay awake, but it also can make you feel tense, jittery, and stressed. Cutting back or even doing away with caffeine can help reduce your feelings of stress.


Life is full of twists and turns. You’ll always have some stress in your life. It helps to understand that there will be good days and bad days.

Nicotine and Schizophrenia

People with Schizophrenia are three times more likely to smoke than other people and tend to have a much more intense habit. It is believed this relationship stems from the belief among sufferers that smoking helps them manage their symptoms and even side-effects of medication. Interestingly, sufferers were found to extract more nicotine per cigarette than other smokers, leading experts to believe there is a relationship between the habit and the condition.

Further research is ongoing, however recent and historic studies have shown that smoking actually increases a person’s risk of developing a mental health disorder including schizophrenia, but the exact links are not fully understood.

While it may play a role in the condition’s development, there are also studies that have demonstrated improvements in patients following the administration of nicotine. With the addictive substance actually normalising some of the cognitive and sensory deficits caused by the condition.

The improvement seen in these cases is believed to be linked to nicotine’s ability to trigger dopamine production in the areas of the brain most affected by schizophrenia. The receptors in the brain which nicotine binds to are involved in the processes impaired by schizophrenia: thinking ability, reward, movement and pain relief.

Patients were actually found to have fewer and poorly functioning examples of these receptors in their bodies, suggesting a strong link between the role of nicotine and potential medication for the condition. Using nicotine was shown to improve eye tracking, sound filtering and adaptation to strong sensory inputs. Enhancements in learning ability, memory and attention span were also noted in sufferers who smoked.

Because of this evidence, experts are now looking to nicotine as a guide to develop a medication that works in a similar way to remedy the issues caused by schizophrenia, without the unintended addiction. If such a thing can be achieved, then there is a positive future for patients who rely on smoking to reduce their symptoms.

Smoking and Medication

While many people smoke without a second thought, doing so can actually impact the effectiveness of a range of medications. If you are already prescribed something and have taken up smoking, it is entirely possible that your dose may need to be adjusted to accommodate the impact on its performance. The impact occurs because smoking triggers the production of an enzyme that breaks down the medication before it can act.

It should be noted that it is the collective compounds delivered when smoking that interfere with certain types of medication, not actually the nicotine itself. While most interactions with medication are not clinically significant, users of the below examples should take note if you have started smoking after beginning a prescription.

You should always consult your GP before making any decision about your medication.


Drug name

Action to take when stopping smoking

Aminophylline, Theophylline

The dose of theophylline may need to be reduced by about one quarter to one third one week after withdrawal. However, it may take several weeks for enzyme induction to dissipate. Monitor theophylline concentration periodically. Advise the person to seek help if they develop signs of theophylline toxicity such as palpitations or nausea.


Be alert for increased adverse effects of chlorpromazine (for example, dizziness, sedation, extra-pyramidal symptoms). If adverse effects occur, reduce the dose as necessary. 


Monitor serum drug levels before stopping smoking and one week after stopping smoking. On stopping smoking, reduce dose gradually over a week until around 75% of original dose reached.
Repeat plasma level one week after stopping smoking. Further dose reductions may be required.


When given to people who smoke, increase the daily dose in 50mg increments at 2-week intervals, up to a maximum dose of 300mg. If the person stops smoking the dose should be immediately reduced to the initial starting dose.


Be alert for signs of opioid toxicity and reduce the methadone dose accordingly.


Be alert for increased adverse effects of olanzapine (for example, dizziness, sedation, hypotension). If adverse effects occur, reduce the dose as necessary.


Dose reductions may be necessary if the person stops smoking, as riociguat exposure is reduced by 50-60% in people who smoke.


If a person taking warfarin stops smoking, their INR might increase so monitor the INR more closely. Advise people to tell the healthcare professional managing their anticoagulant control that they are stopping smoking.


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