Drug usage screening

Drug usage screening or drug testing is commonly a technical examination of urine, blood, semen, sweat, or oral fluid samples to determine the presence or absence of specified drugs or their metabolized traces.

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 enacted executive order 12564, requiring all federal employees refrain from using illegal substances in 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 used in the United States.

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 use 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.
 * 1) Cannabinoids (marijuana, hashish - tests for metabolite THCCOOH)
 * 2) Cocaine (cocaine, benzoylecognine, cocaethylene)- tests for cocaine metabolite)
 * 3) Amphetamines (amphetamine, methamphetamine)
 * 4) Opiates (heroin, opium, codeine, morphine, 6-MAM)
 * 5) Phencyclidine (PCP)
 * 6) Methadone (MTD)
 * 7) Barbiturates (BAR)
 * 8) Benzodiazepines (BZO)
 * 9) Tricyclic antidepressants (TCA)
 * 10) Methylenedioxymethamphetamine (MDMA or ecstasy)

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, Ketamine (Ketamine) and peyote (mescaline) are rarely tested for.

Detection periods
The following chart from LabCorp gives approximate detection periods for each substance by test type. 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.

Urine drug screen
When an employer requests a drug test from an employee, the employee is instructed to go to a collection site. There, the employee’s urine is collected in a specially designed secure cup and sealed with a tamper resistant tape. The cup is then sent by express delivery service to a testing laboratory where it will be tested for several drugs. The first step at the testing site is to split the urine into two aliquots. One aliquot is first screened for drugs using an analyzer that performs immunoassay as the initial screen. If the urine screen is positive then another aliquot of the sample is used to confirm the findings by gas chromatography - mass spectroscopy (GC-MS) methodology. All test results are relayed to an MRO (Medical Review Office) where a medical physician reviews the results. If the result of the screen is negative, the MRO informs the employer that the employee is clean and has no detectable drug in the urine. However, if the test result of the immunoassay and GC-MS are positive, the MRO contacts the employee and tries to determine if there is any legitimate reason for the employee to have a positive result such as a medical treatment or prescription. If it is determined that the positive result is truly due to drug use, the MRO then informs the employer of the positive result. Statistics show that about 5% of the urine samples tested in the U.S. turn out positive for drugs.

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. However, most laboratories performing drug screens test for adulterants routinely.

Adulterants can be classified into two categories. The first category includes classic adulterants comprising household substances and other chemicals such as chlorine bleach, liquid drain cleaner, white vinegar, glutaraldehyde, sodium nitrite, and pyridinium chlorochromate. The second category includes commercial adulterants, which can be purchased from certain specialty stores (so-called “head shops”), through magazine advertisements, or via the Web. This second class of adulterants includes brand names such as Urine Luck version 6.3, Stealth, Clean-X, Klear, Purafyzit, Instant Clean, Krystal Kleen, and UR’n Kleen. Some of the commercial adulterants represent a repackaging of classic adulterants. One adulterant, for example, Klear, is made of nitrite and affects the tetrahyd rocannibinol (THC)confirmation process but not the immunoassay process. Urine Luck 6.3 is actually hydrofluoric acid, which is an oxidant not generally available in the classic adulterants category because of its corrosive nature. Stealth is an enzyme system that generates hydrogen peroxide.

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. Vitamin B3 (niacin) is also frequently used for its reported "flushing" effect, though this is also of disputable adeptness.

Urinalysis can detect the use of these "detox" products.

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. Yeast can be detected 9 to 11 days after consumption but will not show levels consumed.

Hair drug testing
Hair testing is considered accurate and can go back as far as 90 days. , As hair grows out, any drugs used are encased in the hair shaft. Longer hair can reveal an individual's drug history spanning a longer period than shorter hair. Human hair grows an average of .5 inches/month, which corresponds to 30 days of possible drug testing for approximately every .5 inch. Testing laboratories generally require between 0.5 and 1.5 inches for testing. This represents approximately 30 to 90 days of drug use. The standard for hair 1.5 inches or longer is 80 strand or 120 if only .5 inches as it is by picogram weight that the hair is uniformly tested. 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 in the order of face, chest, arm pit, and on some occasions the police use leg hair that has a shorter slower growth rate. If all hair is shaven, the follicles of the hair may be used in place of the hair. Hair follicle testing is normally not part of an employer-based drug testing program using hair.

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. One clinical laboratory conducting hair-testing for drugs of abuse, Psychemedics Corporation, offers a test that has been cleared by the 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 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. In recent years, studies have proven conclusively that ethnicity does not impact the accuracy of a hair test. Misinformation in this area may be promulgated by individuals or organizations attempting to malign the superior detection capabilities of hair-testing.Citation Needed

Shampoos are available to help subjects pass tests, however almost all of the products are just Aloe rid clarifying shampoo some with laundry detergent added. The aloe rid will help during detoxing to cut down on second-hand contamination from sweat and scalp oils. A two-step process that opens the cuticle layer and allows deeper penetration is used. One hair testing laboratory, Psychemedics Corporation, performs extensive wash procedures on each hair sample to eliminate the possibility of a false positive from drug residue on the outside of the hair shaft.

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. Trimega Laboratories were the first company in the UK to commercialize testing for the UK judicial and US judicial system.

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. In the detection of Ethyl Glucuronide, or EtG, testing can detect amounts in picograms (one picogram equals 0.001 nanograms).

However there is one major difference between most drugs and alcohol metabolites 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 lower than (the relevant order of magnitude of) EtG (picogram = one trillionth of a gram). It has been technically possible to measure FAEEs since 1993, and the first study reporting the detection of EtG in hair was done by Sachs in 1993.

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). FAEE concentrations in hair from other body sites can be interpretated in a similar fashion as scalp hair (Hartwig et al., 2003b).

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. Such practices however, may provide disputable results given that to define an individual as an 'excessive drinker' this would need to define a specific alcohol intake [in units]. Since the way an individual metabolises alcohol varies from person to person, the same quantity of alcohol in units would have varying effects from person to person. It is also not scientifically possible to equate a level of metabolite detected in an individual to a quantity of alcohol as a result of individual differences in metabolism.

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.

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
 * Amphetamines
 * Phencyclidine (PCP)

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. And many others

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. 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.

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.

Random drug testing
In the USA, 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 drug 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 could indirectly encourage the use of much more dangerous and harmful drugs that are excreted from the body faster.

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.

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.

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.

Spray (sweat) drug testing
Spray (sweat) drug test kits are non-invasive. 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.

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. The tests can only tell you if drugs have been consumed recently.

United Kingdom
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. However, this 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 in the future to clarify the legal situation regarding workplace drug testing.

United States
Mandatory drug testing entered American life through two separate historical routes. The first was through the common law system, employing precedents philosophically derived from the idiosyncratic rules governing the "king's forest" and the "king's highway". From these arcane precepts are derived the laws which allow legal authorities to detain and test persons under suspicion of driving under the influence of a psychoactive drug.

The second route was more recently constructed and originated from an incident that occurred in the US Navy. After a plane crashed onto the carrier deck of the USS Nimitz in 1981, killing and injuring dozens of personnel, drug testing was instituted immediately. The results revealed a large substance-abusing cohort within the ranks of enlisted persons and officers. As a result of this single incident, the Secretary of the Navy instituted an intensive drug testing and regulation program. These interventions were then adopted by other branches of the service over a three-year period. From these actions was derived the concept of a "drug-free workplace". In consultation with his drug-czar, Dr. Carlton Turner, President Ronald Reagan issued Executive Order 12584. In doing so, he instituted mandatory drug-testing for all safety-sensitive executive-level and civil-service Federal employees. This was challenged in the courts by the Natl. Treasury Employees Union. In 1988, this challenge was considered by the US Supreme Court. In this case, the Court upheld the President's order. A similar challenge resulted in the Court extending the drug-free workplace concept to the private sector. These decisions were then incorporated into the White House Drug Control Strategy directive issued by President George H.W. Bush in 1989.