At a Glance
Why Get Tested?
To screen for drug use, to monitor someone with a substance abuse problem, or to detect and evaluate a drug overdose
When to Get Tested?
Prior to the start of a new job or insurance policy, at random for workplace drug testing and athletic drug testing programs, as mandated when court ordered, as indicated when ordered by a doctor to monitor a known or suspected substance abuse patient, or whenever a person has symptoms that suggest a drug overdose
A random urine sample; sometimes a blood sample drawn from a vein in your arm; rarely hair, saliva, or sweat
Test Preparation Needed?
The Test Sample
What is being tested?
Drugs of abuse testing is the detection of one or more illegal and/or legal substances in the urine or, more rarely, in the blood, saliva, hair, or sweat. It usually involves an initial screening test followed by a second test that identifies and/or confirms the presence of a drug or drugs. Most laboratories use commercially available tests that have been developed and optimized to screen urine for the "major drugs of abuse."
For most drugs of abuse testing, results of initial screening testing are compared with a predetermined cut-off. Anything below that cut-off is considered negative; anything above is considered a positive screening result.
Within each class of drug that is tested, there may be a variety of chemically similar drugs. Legal substances that are chemically similar to illegal ones can produce a positive screening result. Therefore, screening tests that are positive for one or more classes of drugs are frequently confirmed with a secondary test that identifies the exact substance present using a very sensitive and specific method, such as gas chromatography/mass spectrometry (GC/MS).
Some of the most commonly screened drug classes are listed in the table below.
|Drug class screened||Examples of specific drugs identified during confirmation|
|Barbiturates||Phenobarbital, secobarbital, pentobarbital|
|Cocaine||Cocaine and/or its metabolite (benzoylecognine)|
|Opiates||Codeine, morphine, metabolite of heroin|
(See a more comprehensive list of drug classes and drugs of abuse.)
Substances that are not similar to the defined classes can produce false negative results. Some drugs may be difficult to detect with the standardized assays, either because the test is not set up to detect the drug, such as methylenedioxy-methamphetamine (MDMA, Ecstasy), oxycodone (Oxycontin), or buprenorphine, or because the drug does not remain in the body long enough to be detected, such as gamma-hydroxybutyrate (GHB).
For sports testing of hormones and steroids, each test performed is usually specific for a single substance and may be quantitative. Athletes, especially those at the national and international level, are tested for illegal drugs and are additionally governed by a long list of prohibited substances called performance enhancers.
Groups of drug tests are typically ordered for medical or legal reasons, as part of a "drug-free workplace" or as part of a sports testing program. People who use these substances ingest, inhale, smoke, or inject them into their bodies. The amounts that are absorbed and the effects that they have depend on the which drugs are taken, how they interact, their purity and strength, the quantity, timing, method of intake, and the individual person's ability to metabolize and excrete them. Some drugs can interfere with the action or metabolism of other medications, have additive effects such as taking two drugs that both depress the central nervous system (CNS), or have competing effects such as taking one drug that depresses the CNS and another that stimulates it. The drugs tested for are not normally found in the body, with the exception of some hormones and steroids measured as part of sports testing.
How is the sample collected for testing?
Urine is the most frequently tested sample, but other body samples such as hair, saliva, sweat, and blood also may be used for drug abuse screening but not interchangeably with urine.
Urine and saliva are collected in clean containers. A blood sample is obtained by inserting a needle into a vein in the arm. Hair is cut close to the scalp to collect a sample. A sweat sample is typically collected by applying a patch to the skin for a specified period of time.
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.
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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.
Sources Used in Current Review
Pagana, K. D. & Pagana, T. J. (© 2007). Mosby’s Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 892-894.
Clarke, W. and Dufour, D. R., Editors (© 2006). Contemporary Practice in Clinical Chemistry: AACC Press, Washington, DC. Pp 472-474.
Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 1237-1517.
(Updated, 2009 April 14). Substance Abuse Problems. U.S. National Library of Medicine, MedlinePlus Health Topics [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/substanceabuseproblems.html through http://www.nlm.nih.gov. Accessed April 2009.
O'Connor, P. (Revised 2008 July). Drug Use and Dependence. The Merck Manual of Healthcare Professionals [On-line information]. Available online at http://www.merck.com/mmpe/sec15/ch198/ch198a.html through http://www.merck.com. Accessed April 2009.
(2008 January 1). The World Anti-Doping Code, 2008 Prohibited List, International Standard. WADA [On-line information]. PDF available for download at http://www.wada-ama.org/rtecontent/document/2008_List_Format_en.pdf through http://www.wada-ama.org. Accessed April 2009.
Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Burtis CA, Ashwood ER and Bruns DE, eds. 4th ed. St. Louis, Missouri: Elsevier Saunders; 2006, Pp 1317-1351.
Sources Used in Previous Reviews
Thomas, Clayton L., Editor (1997). Taber’s Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].
Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby’s Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.
(2001 March). Drug Abuse: How to Break the Habit. Familydoctor.org [On-line information]. Available online at http://familydoctor.org/x2782.xml?printxml through http://familydoctor.org.
(2000 May 1). An Approach to Drug Abuse, Intoxication and Withdrawal. American Family Physician [On-line journal]. Available online at http://www.aafp.org/afp/20000501/2763.html through http://www.aafp.org.
NIDA Infofax (2001 November 29). Inhalants. The National Institute on Drug Abuse (NIDA) [On-line serial]. Available online at http://www.nida.nih.gov/Infofax/Inhalants.html through http://www.nida.nih.gov.
Office of the National Drug Control Policy (ONDCP) (1998 June) Rohypnol, NCJ-161843. The National Clearinghouse for Alcohol and Drug Information (SAMHSA) [On-line Fact Sheet]. Available online at http://www.health.org/nongovpubs/ondcp-rohypnol/ through http://www.health.org.
Segura, J. (1999 December 21). Sports Drug Testing, Medical and Regulatory aspects. University of Barcelona Olympic Studies Center [Online-index of articles]. Available online at http://www.blues.uab.es/olympic.studies/doping/segura.htm through http://www.blues.uab.es.
Bureau of Forensic Services (2001). Drug Summaries. Office of the Attorney General State of California Dept of Justice [On-line website information]. Available online at http://caag.state.ca.us/bfs/toxlab/summ.htm through http://caag.state.ca.us.
Bureau of Forensic Services (2001). An Introduction To Gas Chromatography / Mass Spectrometry (GC/MS). Office of the Attorney General State of California Dept of Justice [On-line website information]. Available online at http://caag.state.ca.us/bfs/toxlab/gcms.htm through http://caag.state.ca.us.
Dean, M. (2001 October 25). Why Britain is going Dutch. The Guardian [On-line serial]. Available E-mail: email@example.com. Available online at http://www.guardian.co.uk/analysis/story/0,3604,580358,00.html through http://www.guardian.co.uk.
Harrie, D. (2004 January 28). To treat or lock up: Senate backs new drug-offense policy. The Salt Lake Tribune [On-line article]. Available online at http://www.sltrib.com/2004/Jan/01282004/utah/133259.asp?display=print through http://www.sltrib.com.
Downie, A. (2002 January 4). Brazil's drug users will get help, instead of jail. Sweeping new laws are based on the view that drug users need treatment, not criminal punishment. The Christian Science Monitor [On-line serial]. Available online at http://www.csmonitor.com/2002/0104/p7s2-woam.htm through http://www.csmonitor.com.
Reuters (2002 January 2). Florida Reports More Deaths from Oxycontin Abuse. Yahoo News Health Headlines [On-line News Release].
(2003 May 30). Race to develop drug abuse test. BBC News [On-line article]. Available online at http://news.bbc.co.uk/1/hi/health/2946344.stm through http://news.bbc.co.uk.
(2004 February 1). Online drug abuse rife. NEWS.com.au [On-line article]. Available online at http://news.com.au/common/story_page/0,4057,8554330%255E1702,00.html through http://news.com.au.
Locke, J. (2000 July). Alternative Matrices in Drug Testing. Clinical Laboratory Strategies. Available from Jalane: firstname.lastname@example.org.
Locke, J. (2000 July). Olympic and Sports Drug Testing. Clinical Laboratory Strategies. Interview with Larry Bowers, Ph.D., Professor and Director of Athletic Drug Testing and Toxicology Laboratory at Indiana University. Available from Jalane: email@example.com.
Locke, J. (2002 February). Drug Testing. Clinical Laboratory Strategies. Available from Jalane: firstname.lastname@example.org.
Locke, J. (2002 February). Drug Testing – Sidebar on Olympic Drug testing. Clinical Laboratory Strategies. Interview with Don H. Catlin, MD Director of the UCLA Olympic Analytical Laboratory and Lab Director of the Olympic drug lab for the SLC 2002 Olympics. Available from Jalane: email@example.com.
Valentine, J. & Kerrigan, S. (2001). Club or Rave Drugs. Manuscript. Available E-mail: firstname.lastname@example.org.
Larry A. Broussard, PhD. Clinical Laboratory Sciences, LSU Health Sciences Center, New Orleans, LA.
Donald F. LeGatt PhD, FCACB. Clinical Professor, Clinical Biochemist, Department of Laboratory Medicine and Pathology, University of Alberta Hospital, Edmonton, Alberta.