To detect the presence or measure the quantity of nicotine or cotinine in blood, urine, saliva, or sometimes hair. To find out whether someone uses tobacco or has been exposed to second-hand smoke. Rarely, it can be used to check for acute nicotine poisoning.
Whenever someone requires confirmation of tobacco usage or exposure to second-hand smoke. Rarely when nicotine overdose is suspected.
Usually a urine sample is collected, but sometimes a blood sample (from a vein in your arm) or a saliva sample is collected. Rarely a hair sample is collected.
Nicotine is an addictive 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 removed by the kidneys into the urine. Tobacco use and exposure to tobacco smoke can increase nicotine concentrations in the body. Cotinine is the body's main breakdown product (metabolite) of nicotine. Cotinine and nicotine levels also rise with use of nicotine replacement products such as nicotine patches, gums and e-cigarette liquids. Nicotine is poisonous in large amounts.
Cotinine is usually the best test to check for tobacco use or exposure to tobacco smoke because it lasts longer in the body 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 are usually requested instead of nicotine tests.
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 requested in cases of suspected nicotine poisoning. Acute overdoses of nicotine, such as may happen if a child ingests nicotine lozenges or gum, are relatively rare but generally require immediate medical attention. Symptoms can include a burning mouth, feeling sick, abdominal pain, salivating (drooling), diarrhoea, sweating, confusion, dizziness, agitation, increased heart rate, rapid or difficult breathing, convulsions, coma, and even death.
How is the sample collected for testing?
A random urine sample is collected, or a blood sample is obtained by inserting a needle into a vein in the arm. Occasionally a saliva sample may be obtained directly or by soaking a collecting cloth or swab with saliva. Rarely a hair sample may be collected.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
How is it used?
Nicotine or its 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. Some health and life insurance companies test applicants for nicotine or cotinine as well.
Nicotine and cotinine can both be measured qualitatively (test to see if present or absent) or quantitatively (measurement of the actual concentration). 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 exposure of non-smokers to tobacco smoke.
Nicotine or cotinine testing may be performed if a doctor suspects that someone is has had 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 requested. Anabasine is present in tobacco but not in commercial nicotine replacement products. If a sample tests positive for anabasine then the person is likely to be still using tobacco products.
When is it requested?
Cotinine and/or nicotine may be requested whenever an evaluation of tobacco use status or tobacco smoke exposure is required. When someone enters a smoking cessation programme, blood or urine cotinine tests may be requested 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.
Nicotine and cotinine are occasionally measured when a patient has symptoms that the doctor suspects may be due to a nicotine overdose. Symptoms of mild nicotine poisoning may include:
- Feeling sick
More serious nicotine poisoning may result in:
- Increased blood pressure and/or heart rate which then suddenly drops
- Slowed or difficult breathing
Hair testing is rarely performed in a clinical setting but may be requested when an evaluation of longer term tobacco use is desired.
What does the test 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. Concentrations are 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 metabolized, and in the rate that cotinine is removed 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 in whom nicotine overdose is self-evident would not normally 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?
Test results based on different samples (blood, urine or saliva) are not interchangeable.
Some pesticides contain high concentrations of nicotine. This can be another source of nicotine poisoning.
Nicotine is not only found in the tobacco plant, but also in other plants of the same family including potatoes, aubergines, tomatoes and red peppers. The amount of nicotine in these plants is much lower than the level in tobacco, and the cut-off values of the nicotine/cotinine tests have been set to ensure that levels of nicotine in the normal diet do not produce positive tests.
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 (for more on this see Pharmacogenomics).
Are there any forms of tobacco that do not contain nicotine?
No, they all contain nicotine. This includes pipe tobacco, cigars, snuff, chewing tobacco, e-cigarettes, etc. If you use any of these, nicotine may be detected in your system.
Can I be required to be tested for tobacco use?
Since tobacco use is legal for adults this would generally only apply to people who are ordered to be tested by the courts, such as for child-custody reasons, but this is rare. 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.
Where can I find information about smoking cessation?
What kinds of nicotine replacement products are available?
There are a variety of over-the-counter (OTC) products and a few that are available by prescription. OTC products include nicotine gum, patches, lozenges, nasal sprays and e-cigarettes. It is important to follow directions for their use, and 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.