Drug test
From Wikipedia, the free encyclopedia
This article does not cite any references or sources. (February 2007) Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. |
- For the episode of the American television series The Office, see "Drug Testing".
A drug test is commonly a technical examination of urine, semen, blood, sweat, or oral fluid samples to determine the presence or absence of specified drugs or their metabolized traces.
Contents |
[edit] General information about drug testing in the USA
Drug tests in the USA can be divided into two general groups, federally and non-federally regulated testing. Federally regulated testing started when Ronald Reagan executive order 12564, requiring all federal employees to refrain from using illegal and specified DOT regulated occupations. Drug testing guidelines and processes, in these areas exclusively, are established and regulated (by the Substance Abuse and Mental Health Services Administration or SAMHSA, formerly under the direction of the National Institute on Drug Abuse or NIDA) require that companies who use professional drivers, specified safety sensitive transportation and/or oil and gas related occupations, and certain federal employers, test them for the presence of certain drugs. These test classes were established decades ago, and include five specific drug groups. They do not always account for current drug usage patterns. For example, the tests sometimes exclude semi-synthetic opioids, such as oxycodone, oxymorphone, hydrocodone, hydromorphone, etc., compounds that are also abused in the United States.
- Cannabinoids (marijuana, hashish - tests for metabolite THCCOOH)
- Cocaine (cocaine, benzoylecognine, cocaethylene)- tests for cocaine metabolite)
- Amphetamines (amphetamine, methamphetamine)
- Opiates (heroin, opium, codeine, morphine, 6-MAM)
- Phencyclidine (PCP)
While SAMHSA/NIDA guidelines only allow laboratories to report quantitative results for the "NIDA-5" on their official NIDA tests, many drug testing laboratories and on-site tests also offer a wider or "more appropriate" set of drug screens which may be more reflective of current drug abuse patterns. As noted above, these tests include synthetic pain killers such as Oxycodone, Oxymorphone, Hydrocodone, Hydromorphone, benzodiazepines (Valium, Xanax, Klonopin, Restoril) and barbiturates in other drug panels (a "panel" is a predetermined list of tests to run). The confirmation test (usually GC/MS, or LC/MS/MS) can tell the difference between chemically similar drugs such as methamphetamine and methylenedioxymethamphetamine (MDMA or ecstasy), and in the absence of detectable amounts of methamphetamine in the sample, the lab will either report the sample as negative or report it as positive for MDMA. What the lab reports to the client depends upon whether MDMA was included in the panel as something to be tested for.
Gamma-hydroxy-butyrate (GHB) was not routinely tested for in the early 1990s, but due to increasing use, some laboratories have added it as an optional test. GHB is rare in pre-employment screening, but is commonly checked for in suspected cases of drug overdose, date rape, and post-mortem toxicology tests. Ketamine (Special K) may or may not be tested for, depending upon the preferences of the entity paying for the test, though testing for it is uncommon. In general, the greater the number of drugs targeted, the higher the cost of the test, which means that many employers only target the NIDA 5 for financial reasons.
Other drugs, such as meperidine (Demerol), fentanyl, propoxyphene, and methadone are not commonly tested for in most pre-employment situations. These drugs are more likely to be included in tests for certain demographic groups (such as healthcare workers, drug rehab patients, etc.)
Hallucinogens other than cannabis and PCP, such as mushrooms (psilocybin), LSD, and peyote (mescaline) are rarely tested for.
[edit] Detection periods
The following chart from LabCorp gives approximate detection periods for each substance by test type.[1] The ranges depend on amount and frequency of use, metabolic rate, body mass, age, overall health, and urine pH. For ease of use, the detection times of metabolites have been incorporated into each parent drug. For example, heroin and cocaine can only be detected for a few hours after use, but their metabolites can be detected for several days in urine. In this type of situation, we will report the (longer) detection times of the metabolites.
- NOTE 1: Oral fluid or saliva testing results for the most part mimic that of blood. The only exception is THC. Oral fluid will likely detect THC from ingestion up to a maximum period of 18-24 hours
- NOTE 2: Urine can not detect current drug use. It takes approximately 6–8 hours or more post-consumption for drug to be metabolized and excreted in urine. Similarly, hair requires two weeks, and sweat, seven days.
Substance | Urine | Hair | Blood |
---|---|---|---|
Alcohol | 3–5 days via ethyl gluconoride (EtG) metabolite or 10–12 hours via traditional method | lifetime of hair | 12 hours |
Amphetamines (except meth) | 1 to 2 days | up to 90 days | 12 hours |
Methamphetamine | 2 to 4 days | up to 90 days | 24 hours |
Barbiturates (except phenobarbital) | 2 to 3 days | up to 90 days | 1 to 2 days |
Phenobarbital | 7 to 14 days | up to 90 days | 4 to 7 days |
Benzodiazepines | Therapeutic use: 3 days. Chronic use (over one year): 4 to 6 weeks | up to 90 days | 6 to 48 hours |
Cannabis |
|
up to 90 days | 12 days |
Cocaine | 3 to 300 days with exceptions for certain kidney disorders | up to 90 days | 24 hours |
Codeine | 1 day | up to 30 days | 12 hours |
Cotinine (a break-down product of nicotine) | 2 to 4 days | up to 90 days | 2 to 4 days |
Morphine | 2 days | up to 90 days | 6 hours |
Heroin | 2 days | up to 90 days | 6 hours |
LSD | 2 to 24 hours | up to 3 days | 0 to 3 hours |
Methadone | 3 days | up to 30 days | 24 hours |
PCP | 14 days; up to 30 days in chronic users | up to 90 days | 24 hours |
[edit] Common types of drug tests
[edit] Urine drug screen
This procedure requires that one provide a sample of urine. Either a test card is used on site for immediate results (see "General" section), or the sample is sent away to a lab to undergo gas chromatography/mass spectrometry (also known as GCMS), high performance liquid chromatography or immunoassay analysis. The majority of tests administered in pre-hire and even most probate scenarios are of the immediate, and less accurate "at home" variety. Most "dip stick" type tests have higher thresholds for a positive than do the GCMS tests. If a positive result (drug presence indicated) is found, the sample is usually sent to a lab for GCMS confirmation. This is largely due to the costliness of GCMS labaratory testing and time it takes to process and receive results. The results of any urine test reflect factors including, but not limited to age, weight, race, and often these factors are what determines whether the test is valid or not.
The efficacy of urine testing is debatable due to systematic cheating. It is widely reported that sample substitution and adulteration occur frequently, and both are effective methods of avoiding would-be positive tests. There are a number of adulterant "masking" agents that are sold, though they are often nothing more than a simple diuretic and are rarely more effective than caffeine. Some people drink copious amounts of water to successfully dilute the concentration of drug metabolites in their urine below detectable thresholds. Often this results in clear samples that may be rejected on the grounds of being too dilute, although a complex B vitamin will make urine yellow despite this practice of waterloading. Specific gravity testing can be done to identify whether or not the sample is of dilute nature, though this is used infrequently on otherwise inconspicuous samples. The substance Niacin is also frequently used for its reported "flushing" effect, though this is also of disputable adeptness. Some types of urinalysis can detect the use of these "detox" products, though they are rarely used unless some facet of the sample is suspicious. Also, the wide availability of at home drug screens allows an individual to take their own test before they receive one, thus knowing the results ahead of time- giving the user further opportunity to dilute the sample or to find a substitute.
[edit] Hair drug testing
Hair testing is considered accurate and can go back as far as 90 days.[citation needed] As hair grows out, any drugs used are encased in the hair shaft, so the longer the hair, the more time back in the individual's drug history the laboratory can detect. Human hair grows an average of .5 inches/month, which corresponds to 30 days of possible drug testing for every .5 inch. Testing laboratories generally require 1.5 inches for testing. This means they can test for around 90 days of drug use. This time period depends upon the rate at which the individual's hair grows of course. Some people attempt to circumvent this through shaving their heads. This does not usually work. In the absence of the required amount of hair on the scalp, body hair can be used as an acceptable substitute. If all hair is shaven, the follicles of the hair may be used in place of the hair. Removing the hair follicles is more painful.
Additionally for pre-employment hair testing, the inability to obtain a sample may be grounds for not hiring the individual. Hair Testing labs are regulated by CLIA or SAMHSA (not FDA). There is a growing trend in major companies and law enforcement agencies to utilize hair analysis on account of its efficiency and reputation as the gold standard when considering test accuracy. This technology makes use of radioimmunoassay or the more modern ELISA technology with subsequent confirmation by mass spectrometry.
In recent years, hair testing has been the subject of a number of lawsuits. Studies have shown that different ethnic groups have different hair structure, potentially leading to false positives[citation needed]. Shampoos are available to help you pass but you would have to shave your legs and body hair to make sure they take a sample from your head.
[edit] Hair alcohol testing
As the hair grows, it absorbs special markers called fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) into its structure, which remain in the hair indefinitely. These markers are only produced when there is alcohol in the bloodstream, such that the more markers there are, the more alcohol you have consumed.
Tests detecting both FAEE and EtG levels have been used by UK courts.[citation needed]
Analysis of hair samples has many advantages as a preliminary screening method for the presence of toxic substances deleterious to health after exposures in air, dust, sediment, soil and water, food and toxics in the environment. The advantages of hair analysis include the non-invasiveness, low cost and the ability to measure a large number of, potentially interacting, toxic and biologically essential elements. Hence, head hair analysis is now increasingly being used as a preliminary test to see whether individuals have absorbed poisons linked to behavioral health problems.[2]
The use of hair alcohol analysis to establish and verify persistent alcohol abusers within the United Kingdom has steadily increased in recent years.
In contrast to other drugs consumed, alcohol is not deposited directly in the hair. For this reason the investigation procedure looks for direct products of ethanol metabolism. The main part of alcohol is oxidized in the human body. This means it is released as water and carbon dioxide. One part of the alcohol reacts with fatty acids to produce esters. The sum of the concentrations of four of these fatty acid ethyl esters (FAEEs: ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) are used as indicators of the alcohol consumption. The amounts found in hair are measured in nanograms (one nanogram equals only one billionth of a gram), however with the benefit of modern technology, it is possible to detect such small amounts.
However there is one major difference between most drugs and alcohol metabolites (FAEE) in the way in which they enter into the hair: on the one hand like other drugs FAEEs enter into the hair via the keratinocytes, the cells responsible for hair growth. These cells form the hair in the root and then grow through the skin surface taking any substances with them. On the other hand the sebaceous glands produce FAEEs in the scalp and these migrate together with the sebum along the hair shaft (Auwärter et al., 2001, Pragst et al., 2004). So these glands lubricate not only the part of the hair that is just growing at 0.3 millimeters per day on the skin surface, but also the more mature hair growth, providing it with a protective layer of fat.
FAEEs (nanogram = one billionth of a gram) appear in hair in almost one order of magnitude higher than (the relevant order of magnitude of) Etg (picogram = one trillionth of a gram). It has been technically possible to measure FAEEs since 1993, whereas the technique for measuring (the relevant range of) Etg is still in its infancy.
In practice, most hair which is sent for analysis has been cosmetically treated in some way (bleached, permed etc.). It has been proven that FAEEs are (surprisingly) not significantly affected by such treatments (Hartwig et al., 2003a). So far no systematic investigations in this regard have been carried out for Etg
FAEE concentrations in hair from other body sites can be interpretated in a similar fashion as scalp hair (Hartwig et al., 2003b). Etg: no information available.
Extensive studies involving over 1000 donors have been carried out since 2000. These have enabled us to establish reliable reference ranges for FAEEs with respect to drinking habits of the various groups: non-drinkers < 0,4 ng/mg Excessive drinkers > 1ng/mg
There are no reliable reference ranges for Etg from comprehensive studies. Further investigations are in progress to examine the applicability of the method in practice of the detection of alcohol abuse.
Literature Pragst F., Balikova M.A.: State of the art in hair analysis for detection of drugs and alcohol abuse; Clinica Chimic Acta 370 2006 17-49.
Auwärter V.: Fettsäureethylester als Marker exzessiven Alkoholkonsums – Analytische Bestimmung im Haar und in Hautoberflächenlipiden mittels Headspace-Festphasenmikroextraktion und Gaschromatographie-Massenspektrometrie. Dissertation Humboldt-Universität Berlin 2006.
Pragst F., Auwärter V., Kiessling B., Dyes C.: Wipe-test and patch-test ror alcohol misuse based on the concentration ratio of fatty acid ethyl esters and squalen CFAEE/CSQ in skin surface lipids. Forensic Sci Int 2004; 143:77-86.
[edit] Saliva drug screen / Oral fluid-based drug screen
Saliva / oral fluid-based drug tests can generally detect use during the previous few days. Saliva or oral fluid based drug tests are becoming more prevalent because of their convenience and the fact that they can not be adulterated. Furthermore, on-site oral based tests in particular enable the implementation of random testing programs, proven to be the most effective type of drug screening. Oral fluid based tests are as accurate as urine and can be obtained from suppliers in the United States. Testing is usually performed by employers, for either pre-employment, random, post-accident, reasonable suspicion, or return-to-duty testing. Oral fluid based testing most closely mimics results found with blood and is preferable for detecting on-the-job drug use or in post-accident applications in this case because the degree of intoxication can be approximated based on the amount of substance.
Detection in saliva tests begins immediately upon use:
- Marijuana and hashish (THC): An hour after ingestion, and up to 24 hours depending on use.
- Cocaine (including crack): From time of ingestion up to 2 to 3 days.
- Opiates: From time of ingestion up to 2 to 3 days
- Methamphetamine and ecstasy (MDMA, "crank," "ice"): From time of ingestion up to 2 to 3 days.
- Benzodiazepines: From time of ingestion up to 2 to 3 days
[edit] Sweat drug screen
Sweat tests are patches attached to the skin to collect sweat over a long period of time (10–14 days). These are almost exclusively used by child protective services, parole departments, and other government institutions concerned with drug use over long periods, when urine testing is not practical. The patches have security features that keep them from being covertly removed and then reapplied without the knowledge of the testing agency. At the end of the test period, the patch is removed by a social worker or parole officer and sent to a lab for analysis. If the person has used any drugs during the period that the patch was in place, they will test positive for that drug. This type of testing has fallen out of favor with government agencies due to documented problems with certain drugs[2].
[edit] Drug testing methodologies
The different types of drug tests are tested in very similar ways. Before testing the sample, the tamper-evident seal is checked for integrity. If it appears to have been tampered with or was damaged in transit, the laboratory rejects the sample and does not test it.
One of the first steps for all drug tests is to make the sample testable. Urine and oral fluid can be used "as is" for some tests, but other tests require the drugs to be extracted from urine beforehand. Strands of hair, patches, and blood must be prepared before testing. Hair is washed in order to eliminate second-hand sources of drugs on the surface of the hair, then the keratin is broken down using enzymes. Blood plasma may need to be separated by centrifuge from blood cells prior to testing. Sweat patches are opened up and the sweat collection component is soaked in a solvent to dissolve any drugs present.
Laboratory-based drug testing is done in a two-tiered fashion using two different types of detection methods. The first is known as the screening test, and this is applied to all samples that go through the laboratory. The second, known as the confirmation test, is only applied to samples that test positive during the screening test. Screening tests are usually done by immunoassay (EMIT, ELISA, and RIA are the most common). A "dipstick" drug testing method which could at some future time provide screening test capabilities to field investigators has been developed at the University of Illinois.[3] Screening tests are typically less sensitive and more prone to false positives and false negatives than the confirmation test.
After a suspected positive sample is detected during screening, the sample is flagged and tested using the confirmation test. Samples that are negative on the screening test are discarded and reported as negative. The confirmation test in most laboratories (and all SAMHSA certified labs) is performed using mass spectrometry, and is extremely precise but also fairly expensive to run. False positive samples from the screening test will be negative on the confirmation test. Samples testing positive during both screening and confirmation tests are reported as positive to the entity that ordered the test. Most laboratories save positive samples for some period of months or years in the event of a disputed result or lawsuit. For workplace drug testing, a positive result is generally not confirmed without a review by a Medical Review Officer that will normally interview the subject of the drug test.
[edit] Types of testing
The examples and perspective in this article or section may not represent a worldwide view of the subject. Please improve this article or discuss the issue on the talk page. |
[edit] Pre-employment drug testing
This is by far the most common type of drug test used by businesses. It has the advantage of being inexpensive, since only one test per employee needs to be paid for by the company. However, since most pre-employment drug testing is urine-based and subject to sample adulteration or substitution, the effectiveness of this approach has been questioned by federal legislators. Some organizations have a witness in the room at the time of the testing, but the privacy implications of this, as well as the potential for shy bladder syndrome has limited the use of witnesses outside jails and drug treatment programs. Companies and testing centers that do not use witnesses normally disconnect sources of water from the testing room to discourage dilution, and if there is water in the toilet, it is dyed blue. Other countermeasures, such as making the donor change into a gown, may also be used.
[edit] Random drug testing
In the United States, random drug testing is used by a growing number of corporations, drug rehab centers, prisons, the military, police and fire departments, government agencies, and more recently, schools. This method may also be used on teens by their parents, or mandated to be performed at school. The objective of a random drug test is deterrence, as the threat of detection is much higher versus other testing methods. Various random selection methods are used, ranging from drawing names out of a hat to using random number generators. The random selection methodology is often legally questionable because it is difficult to prove that an individual was not targeted. For example, an employer paying a Third Party Administrator to make random selections could easily instruct the administrator to select an individual. Government-mandated testing requires a scientifically provable method of randomization, although there are no government regulations about tamper-proof selection records. Any procedure without tamper-proof records is open to legal challenge because an employer can not prove that the subject was not targeted.
The goal of random testing is to discourage drug use among employees, inmates, or students by not telling anyone who or when or where they are to be tested in advance. However, critics claim that random testing introduces a presumption of guilt, and is a violation of privacy if the drug user is not actually intoxicated during working hours. In addition, random testing is more likely to catch cannabis users, since THC metabolites are fat soluble and have a longer duration in the body than those of many other drugs. It has been suggested that this indirectly encourages the use of much more dangerous and harmful drugs that are excreted from the body faster.
[edit] Post-incident drug testing
Post-incident drug testing is not a very commonly administered test compared to the other two, but the financial ramifications of not testing employees after an accident (or other incident) on the job makes this test worthwhile for most businesses. The point of this test is not necessarily to cause the employee to lose his or her job, but rather to protect the company from liability in the event that the individual is under the influence at the time of the accident. If drugs or alcohol are detected in any significant quantity, the argument can be made in court that the individual was intoxicated on the job, and for that reason, the company should not be held liable for injuries sustained by the employee. This argument, however, can only reasonably be made if blood or oral fluid / saliva testing is used. Urine, hair, or sweat based testing can only detect past drug use. Depending upon the facts of each case, this may help a company avoid litigation completely or may do nothing to help their case. DUI testing would also fall into this category. Another time this type of test may be used is if an employee shows up for work intoxicated, has alcohol on his or her breath, or appears to be impaired in some other way. The goal of these tests is to protect the entity from litigation, so they are only given on an as needed basis.
It should be noted that in most areas, blood testing is the only legally defensible means for detecting drug use after an incident, although saliva testing is gaining acceptance. The sample should follow chain of custody requirements and should always be sent to a lab after collection. Positive on-site tests that may affect an employee's position or situation should always be followed up with a laboratory test before any action is taken against the employee. Laboratory tests (urine or blood) are the only legally recognized tests in most states as well as in most non-U.S. countries.
[edit] Drug testing methods
[edit] Urine drug testing
Urine drug test kits are available as on-site tests, or laboratory analysis. Urinalysis is the most common test type and used by federally mandated drug testing programs.
The main disadvantages of urine-based drug test kits is/are (1.) the ease at which they can be "cheated" via simple adulteration or substitution, unless specimen collection is directly observed, (2.) inability to detect current / on-the-job drug abuse, (3.) the need for bathroom facilities, and (4.) with respect to SAMHSA-5, or NIDA-5, the inability to test for drugs used in current society.
[edit] Saliva drug testing
Saliva (oral) drug test kits are very donor friendly, non-invasive and easy to collect the specimen. There is no need for a bathroom to administer the tests. Saliva drug testing tends to detect very recent drug use. Also these drug tests are harder to adulterate than the urine drug tests since the sample can be obtained under direct supervision. Results can be read in minutes, however tend to still take longer and cost more than urine screening tests. Depending on the test, up to 8 (5 or 6 at a time) different drugs could be detected. This method is the best method for determining recent use and is a potential indicator of impairment.
The main disadvantage of saliva based drug testing is a difficulty in detecting some drug types such as benzodiazepines and marijuana with sufficient accuracy using point of care equipment. Although detecting impairment is one of the major advantages, it is not necessarily the case that all impaired people will correctly be identified as positive using a saliva test when they should. Another disadvantage is that saliva is a potentially infectious medium and can harbour infection and disease. Accordingly, saliva specimens need to be handled with considerable care.
[edit] Spray (sweat) drug testing
Spray (sweat) drug test kits are non-invasive and donor friendly. It is very easy to collect the specimen and no bathroom is needed for taking the specimen. The detection window is long and usually can detect drug use up to a couple of weeks. These drug tests are relatively tamper proof since they are hard to manipulate. There is no need for a lab and you can get results in minutes.
The main disadvantage of spray or sweat based drug testing is the fact that they are open to contamination. Also large variations of sweat production rates of possible donors make some results inconclusive. There is not much variety in these drug tests since they are not as popular as urine or saliva drug testing kits. Their prices tend to be higher per test conducted. One main disadvantage of this testing method is the limited number of drugs that can be detected.
[edit] Hair drug testing
Hair drug testing can provide a much longer window of detection, which is useful for highly safety critical positions where there is zero tolerance of drug usage. Even if the person being tested has a shaved head (perhaps in preparation for the test), hair can also be taken from almost any other area of the body. This includes the underarms, arms, legs, and pubic area.
It costs more than urine testing, and one must have a lab for results.
[edit] Legality and ethics of mandatory drugs testing
[edit] United Kingdom
Test -The legal position of drug tests on the UK is not clear. A study in 2004 by the Independent Inquiry into Drug Testing at Work found that attempts by employers to force employees to take drug tests could potentially be challenged as a violation of privacy under the Human Rights Act 1998 and Article 8 of the European Convention of Human Rights[4]. However, this certainly does not apply to industries where drug testing is a matter of personal and public safety or security rather than productivity. European Union legislation is expected soon to clarify the legal situation regarding workplace drug testing.
[edit] See also
[edit] External links
- US National Institute on Drug Abuse (NIDA) Website
- US Substance Abuse and Mental Health Services Administration (SAMHSA) Website
- Marijuana Detection Time Shorter Than Previously Assumed
- What You Need to Know about Drug Testing Methods
- The National Clearinghouse for Alcohol and Drug Information
- A Political History of White House Drug Policy
- Ronald Reagan's Executive Order 12564
- The (US) National Institute on Alcohol Abuse and Alcoholism
- European Workplace Drug Testing Society
- European Monitoring Centre for Drugs and Drug Addiction
- The Drug and Alcohol Testing Industry Association
- Erowid Drug Testing Information
[edit] References
- ^ "Drugs of Abuse Reference Guide," LabCorp Inc, Retrieved online April 11, 2007.
- ^ Federal Court Drug-Testing Device Under Fire, PharmChem Sweat Patch May Be "Too Good" (2001-01-05).
- ^ Jim Barlow. "A Little Dab Will Do It", LASNews, University of Illinois, November 2006. Retrieved on 2006-11-29.
- ^ Drug testing in the workplace: Summary conclusions of the Independent Inquiry into Drug Testing at Work. Retrieved on 2008-01-17.