Nicotine

What is nicotine?

Nicotine is the most widely used drug of abuse. It's usually taken by smoking or chewing tobacco, which then releases the nicotine, and is used by millions of people around the world.

Nicotine works by travelling rapidly from lungs to brain (in about seven seconds) where it stimulates the release of dopamine, an important brain neurotransmitter involved in mood, appetite and other brain functions.

Although usually taken for its tranquillising and mildly mood-elevating properties, nicotine actually seems to have both a stimulant and a depressant effect - the effect at any time may depend on the circumstances in which it is used. So it may help with concentration or relax the user.

Nicotine is generally recognised to be one of the most addictive of all drugs. Users can quickly become dependent on its effects (in the most vulnerable, it takes just a few cigarettes to get hooked on the habit).

If someone suddenly stops taking nicotine, they usually experience prolonged withdrawal symptoms such as anxiety and mood swings. This causes them to crave the drug in order to try to reverse these unpleasant feelings. As a result the habit is hard to break.

The fact that smoking or chewing tobacco is not illegal and has some social acceptance (although it has becoming much less so in recent years) makes it harder to give up. Many argue that if tobacco were to be discovered today, it would be considered too dangerous to be licensed for human consumption.

Risks of nicotine

As a pure drug, nicotine has few adverse effects on physical health, however it does raise blood pressure and accelerates the progression of heart and arterial disease. But it's the other chemicals taken in along with nicotine which do much of the damage. When tobacco burns as a cigarette is smoked, it releases hundreds of other constituents. It is these chemicals, described below, that pose the greatest risk to health.

Smoking increases the risk of cancer in almost every organ and tissue of the body, but especially cancer of the lung, throat and stomach. Heart disease, stroke and serious lung disorders, such as chronic obstructive pulmonary disease (commonly known as chronic bronchititis and emphysema) are just some of the reasons why smokers are much more likely to die young, often years before their non-smoking peers. It's estimated that smoking accounts for more than 110,000 premature deaths in the UK each year.

What's in a cigarette?

There are more than 4,000 chemicals in cigarette smoke, some of which are well known for their toxicity. Here are just a few:

• Nicotine - immediate physiological effects include increased heart rate and a rise in blood pressure
• Ammonia - also found in toilet cleaners
• Acetone - found in nail varnish remover
• Cadmium - a highly poisonous metal used in batteries
• Vinyl chloride - used to make PVC
• Napthtalene - used in moth balls
• Carbon monoxide - poisonous gas that is commonly given off by exhausts and gas fires, fatal in large amounts
• Tar - thick brown stuff in cigarette smoke that stains fingers and teeth a yellow-brown colour and which deposits in a smoker's lungs, clogging them up
• Cyanide - a lethal gas used in Second World War gas chambers
• Formaldehyde - used to preserve dead bodies
• Arsenic - poison

Some cigarettes include flavourings include childhood favourites such as cocoa, vanilla, liquorice, sugar and even honey.

Did you know...?

• Addiction to nicotine is usually established in young smokers within about a year of first experimenting with cigarettes, in many cases before reaching the age at which it is legal to buy cigarettes (on average at 12-13 years of age)
• It can take less than one pack of cigarettes - on average, just six cigarettes - to suffer withdrawal symptoms if you try to stop, in other words to become addicted
• Smoking causes permanent changes in brain receptors - once hooked most people will have cravings for nicotine which will never completely leave
• 80 per cent of ex-smokers will return to a regular habit within one month of having just one cigarette, even if they gave up years before
• People who smoke mild cigarettes simply drag longer and harder in order to get the same amount of nicotine and as a result they more often develop peripheral lung tumours at the edges of the lungs and vertical pursing lines around their lips
• Only about five per cent of smokers seek help to quit, even though this can increase their chances of stopping long term to as much as 30 per cent at one year if they get support from a trained adviser and use medications for nicotine dependency

Giving up smoking

About half of all smokers make at least one attempt to stop in a given year. A significant number may do well at first - the data varies but some studies suggest that over 40 per cent of those who use all available help, including nicotine replacement treatment and behavioural support, are initially successful.

Quitting completely is a different matter. Long-term success is much less common and typically more than 95 per cent relapse within the first year, leaving only two to three per cent of those who try with willpower alone and no support from health professionals or medical treatments as successful long-term quitters.

Here are some of the strategies offered to help people stop smoking.

1. Assessment and advice

In most GP surgeries, there are doctors or nurses who offer a brief assessment of a smoker's habit and advice on giving up. This is enough to help about 10 per cent of people to quit completely. Some studies have also shown that telephone contact with an ex-smoker can have a positive effect on increasing the proportion of people who are able to quit over the long term. There have also been some encouraging results from studies that have looked at personalised feedback about smoking and a personalised self-help manual.

2. Behavioural treatments

These are more intensive approaches that combine assessment and advice with help on people increasing their motivation and skills to resist the urge to light up and to cope with cravings. These behavioural treatments often involve the smoker joining a Quit Smoking group or similar sort of programme where they work alone or with others, with a specially trained therapist. Study results show that about one person in seven is able to abstain for at least six months after taking part.

3. Nicotine replacement therapy (NRT)

NRT works by providing a source of nicotine after the person has stopped smoking, such as nicotine patches. This can be an effective method of reducing withdrawal symptoms and the cravings to smoke. Smokers get used to not having cigarettes, while still having a source of nicotine which they then slowly cut down.

With this type of treatment, about 10 per cent of people stop smoking for more than one year (although figures vary), and for every 20 people who use NRT one will become a long term quitter.

Other types of nicotine therapy are available - nicotine gum, lozenges, nasal spray, sublingual (under the tongue) tablets and the nicotine inhaler. Some recent studies have looked at combination treatment, which combines patches and gum and these seem to be even more effective than patches alone.

4. Other medicines

Bupropion (Zyban) and varenicline (Champix) are other medicines that can help a person stop a nicotine habit. They may be preferred by people who would rather not use nicotine replacement therapy (NRT) or who suffer side effects.

Bupropion acts on the dopamine system in the brain to help reduce withdrawal symptoms and cravings (and also therefore acts as an antidepressant). Generally, people taking this medication find that when they stop smoking the withdrawal symptoms and cravings are much easier to deal with. As with any medicine there may be side effects - for example, some people complain they get a dry mouth and others have trouble sleeping - so it isn't suitable for everyone. For every 15 people who use bupropion, one will become a long-term quitter.

Varenicline provides a constant low level stimulation of the nicotine receptors in the brain and makes cigarettes taste awful so the smoker they can't see the point of taking them as there is no nicotine 'hit'. For every eight people who use varenicline, one will become a long-term quitter.

Remember, always consult your doctor first.

(Data from the Cochrane Review 2007).

The success rates quoted above are for when one medication is used at a time. It's now known that if two different medicines are used in combination, success rates may be higher.