What is being tested?
Nicotine is an addictive alkaline chemical found in the tobacco plant and concentrated in its leaves. It is inhaled with each puff on a cigarette and ingested with chewing tobacco. Nicotine is metabolised by the liver into more than 20 compounds, which are excreted by the kidneys into the urine. Both tobacco use and exposure to tobacco smoke can increase nicotine and its primary metabolite, cotinine, concentrations in the body. Levels also rise with nicotine replacement products such as nicotine patches and gums. In large amounts, nicotine can be poisonous.
Cotinine is the major metabolite of nicotine and is usually the test of choice to evaluate tobacco use or exposure to tobacco smoke because it is stable and is only produced when nicotine is metabolised. Cotinine has a half-life in the body of between 7 and 40 hours, while nicotine has a half-life of 1 to 4 hours. Blood and/or urine cotinine tests may be ordered along with nicotine tests. In some cases, other nicotine metabolites, such as nicotine-1´-N-oxide, trans-3´-hydroxycotinine, or nornicotine, or other tobacco chemicals, such as anabasine in urine, may also be tested.
The presence of nicotine and/or cotinine in an individual's sample may indicate the use of tobacco products or exposure to environmental tobacco smoke. Testing may be used in a number of situations to evaluate the possible use of tobacco products such as in smoking cessation programs, prospective employment assessments, and evaluations of applicants for health or life insurance.
Nicotine and cotinine testing may also be ordered in cases of suspected nicotine poisoning. Acute overdoses of nicotine, such as might happen if a child ingests nicotine lozenges or gum, are relatively rare but generally require immediate medical attention. Symptoms can include a burning mouth, nausea, abdominal pain, salivating (drooling), diarrhoea, sweating, confusion, dizziness, agitation, increased heart rate, rapid or difficult breathing, convulsions, coma, and even death.
How is it used?
Nicotine or its primary metabolite, cotinine are most often tested to evaluate tobacco use. Long term use of tobacco products can increase the risk of developing many diseases including lung cancer, COPD, stroke, heart disease, and respiratory infections, or exacerbate asthma, and blood clot formation. In pregnant women, smoking can retard foetal growth and lead to low birth weight babies.
Because use of tobacco products can greatly affect the health of individuals, companies may use nicotine/cotinine testing to evaluate prospective employees for tobacco use. Many health and life insurance companies test applicants for nicotine or cotinine as well.
Nicotine and cotinine can both be measured qualitatively or quantitatively. Quantitative testing can help distinguish between active smokers, tobacco users who have recently quit, non-tobacco-users who have been exposed to significant environmental tobacco smoke, and non-users who have not been exposed.
Cotinine may also be measured in saliva and in hair, although hair testing is primarily used in a research setting, such as a study of non-smokers exposure to tobacco smoke.
Blood or urine nicotine may be ordered by itself or along with cotinine if a doctor suspects that someone is experiencing a nicotine overdose.
When a patient has reported that they are using nicotine replacement products but are no longer smoking, nicotine, cotinine, and urine anabasine measurements may sometimes be ordered. Anabasine is present in tobacco but not in commercial nicotine replacement products. If a sample tests positive for anabasine, then the person is still using tobacco products.
When is it requested?
Cotinine and/or nicotine may be ordered whenever an evaluation of tobacco use status or tobacco smoke exposure is required. When a person enters a smoking cessation programme, blood or urine cotinine tests may be ordered to evaluate compliance. Urine, blood, or saliva testing may be performed as a screen for tobacco use when someone is applying for life or health insurance, or applying for work with an employer that prohibits smoking. Testing may also be ordered by a court for child custody purposes. Since smoking can increase the risks of medical complications, testing may be performed prior to the start of some drug therapies or surgical procedures.
Nicotine and cotinine are sometimes measured when a patient has symptoms that the doctor suspects may be due to a nicotine overdose. Symptoms of mild nicotine poisoning may include:
More serious nicotine poisoning may result in:
Hair testing is rarely performed in a clinical setting but may be ordered when an evaluation of longer term tobacco use is desired.
What does the result mean?
In the blood, nicotine levels can rise within a few seconds of a puff on a cigarette. The quantity depends on the amount of nicotine in the cigarette and the manner in which a person smokes, such as how deeply they inhale. Test results are not interchangeable. Concentrations will be higher in urine than in blood or saliva. There is also some variability from person to person and some genetic differences in the rate that nicotine is metabolised and in the rate that cotinine is cleared from the body. When someone stops using tobacco and nicotine products, it can take more than two weeks for blood levels of cotinine to drop to the level that a non-tobacco user would have and several weeks more for urine levels to decrease to very low concentrations.
In general, high levels of nicotine or cotinine indicate active tobacco or nicotine replacement use. Moderate concentrations indicate a tobacco user who has not had tobacco or nicotine for two to three weeks. Lower levels may be found in a non-tobacco user who has been exposed to environmental smoke. Very low to non-detectable concentrations are found in non-tobacco users who have not been exposed to environmental smoke or a tobacco user who has refrained from tobacco and nicotine for several weeks.
Patients whose nicotine overdose is self-evident may not be tested for nicotine or cotinine. Concentrations would typically be increased, but levels do not necessarily correlate with the severity of a person's symptoms.
Is there anything else I should know?
Some pesticides contain high concentrations of nicotine. This can be another source of nicotine poisoning.
Nicotine is found not just in the tobacco plant but also in other plants in the same family. These include potatoes, tomatoes, eggplants, and red peppers. The concentration of nicotine in these plants, however, is much lower than that in tobacco.
A person's genetic makeup may influence how they metabolise nicotine. Variations in the genes that code for the CYP2A6 and CYP2B6 liver enzyme affect the rate of nicotine metabolism.
Common questions
No, they all contain nicotine. This includes pipe tobacco, cigars, snuff, chewing tobacco, etc. If you use any of these, nicotine may be detected in your system.
Since tobacco use is legal for adults, this would generally only apply to people who are court-ordered to be tested, such as for child-custody reasons. However, since smokers tend to have higher health costs and are at an increased risk for developing a variety of diseases, some health and life insurance companies may require their applicants to be tested for tobacco use prior to accepting them as clients.
E-cigarettes and other electronic nicotine delivery systems (ENDS) use concentrated liquids that are heated to produce a vapour that is then inhaled. The concentrations may contain nicotine, nicotine and flavourings, or just flavourings. If nicotine is present in the concentrate, then it may be detected in your system. This concentrate also poses a risk for accidental nicotine poisoning. The ENDS products are currently thought to be less harmful than smoking, but the medical community is concerned about their growing popularity. Because they are relatively new, their long-term health effects have yet to be determined.
There are many national organisation and government resources available. See the links on the related information page below for more information.
There are a variety of over-the-counter (OTC) products and a few that are available by prescription. OTC products include nicotine gum, patches, and lozenges. Those available by prescription include nicotine patches, inhalers, and nasal sprays. It is important to follow directions for their use and to keep them away from children. The products are intended to be used in conjunction with a smoking cessation programme. Talk to your doctor about the best options for you.
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