A COT (cotinine) drug test is a common method used to detect whether an individual has recently used nicotine or been exposed to tobacco products. Its primary purpose is to objectively determine the presence of nicotine byproducts rather than relying on self-reported information.
Understanding Cotinine
Cotinine is a primary metabolite of nicotine, meaning it is a substance produced when the body breaks down nicotine. Nicotine is primarily metabolized in the liver by the enzyme CYP2A6. About 80% of inhaled nicotine is converted to cotinine.
Cotinine is the preferred substance for testing because it remains in the body for a longer duration than nicotine itself. Nicotine has a relatively short half-life of approximately 60 minutes to a few hours, while cotinine has a much longer half-life, ranging from 7 to 40 hours. This extended presence makes cotinine a more reliable biomarker for recent nicotine exposure and a more stable indicator of tobacco use compared to measuring nicotine directly.
How COT Tests Work
COT tests can be performed using various biological samples, each offering a different detection window. Urine tests are common, detecting cotinine for approximately 2 to 4 days after nicotine use. Urine samples are collected in a clean container, and some rapid tests can provide results within 5 to 10 minutes.
Saliva tests are also utilized, with a detection window typically ranging from 1 to 4 days. These tests involve collecting an oral fluid sample, and they are considered sensitive for detecting recent usage. Blood tests can detect cotinine for several days, generally up to 7 to 10 days after stopping tobacco use. A blood sample is usually drawn from a vein and sent to a lab for analysis.
Hair follicle tests offer the longest detection window, capable of identifying nicotine use for up to 90 days or even months after cessation. Nicotine metabolites become incorporated into the hair shaft as hair grows, providing a record of exposure over time. While highly accurate, hair tests are less frequently administered due to their higher cost.
Applications and Results
COT drug tests are applied in several practical scenarios. They are frequently used in employment screening, particularly by companies with tobacco-free workplace policies. Life and health insurance companies may also require these tests as part of a medical examination before approving a policy, as tobacco use can affect insurance premiums.
In smoking cessation programs, cotinine levels can be measured to estimate prior nicotine consumption and to confirm adherence to quitting efforts. These tests can also be used in clinical settings to assess suspected nicotine poisoning. Results indicate the presence or absence of cotinine, with levels quantified in nanograms per milliliter (ng/mL).
A positive result signifies recent tobacco or nicotine use. Levels can sometimes indicate the extent of use; for example, cotinine levels below 10 ng/mL suggest a non-smoker, while levels between 11-30 ng/mL might indicate light smoking or significant secondhand smoke exposure. Levels exceeding 500 ng/mL are associated with heavy smoking. Factors such as exposure to secondhand smoke or the use of nicotine replacement therapies (like patches or gum) can influence results, as these also introduce nicotine into the body, which is then metabolized into cotinine.