The Test Sample
What is being tested?
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 and subsequently absorbed into the blood. This testing detects and/or measures nicotine and its primary breakdown product (metabolite) cotinine in the blood, urine, saliva, or hair.
Nicotine is metabolized by the liver into more than 20 compounds, which are eliminated from the body in the urine. Both tobacco use and exposure to tobacco smoke can increase nicotine and cotinine concentrations in the body. Levels also rise with use of nicotine replacement products such as nicotine patches and gums. In large amounts, nicotine can be poisonous.
Cotinine 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 metabolized. 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 anabasine in someone's urine indicates that the person is actively using a tobacco product, as it is not found in commercial nicotine replacement products, such as a patch.
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), diarrhea, 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.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.