Nicotine / cotinine

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Formal name: Nicotine; cotinine

At a Glance

Why Get Tested?

To detect the presence of and/or measure the quantity of nicotine or cotinine in blood, urine, saliva, or sometimes hair; to determine whether someone uses tobacco or has been exposed to second-hand smoke; sometimes performed to evaluate for acute nicotine poisoning

When to Get Tested?

Whenever someone requires confirmation of tobacco usage or exposure to second-hand smoke; occasionally when nicotine overdose is suspected

Sample Required?

A blood sample collected from a vein in your arm or a random urine sample; sometimes a saliva sample or, rarely, a hair sample

The Test Sample

What is being tested?

Nicotine is a 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 the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm and/or a random urine sample is collected. 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.

The Test

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.