An inexpensive basic tool to detect substance abuse, the five-panel drug screen is sensitive for marijuana, cocaine, amphetamines, opiates and PCP. Most substances the panels test for appear in urine in six to eight hours and remain three to seven days. Standards for federal employee tests have not kept pace with drug abuse trends and may miss semisynthetic opioids, designer drugs, inhalants, halucinogens, tranquilizers, barbituates and synthetic pain pills. Manufacturers of test kits offer more appropriate panels to employers, treatment centers, court officers, social workers and others who use drug screens.
History
President Ronald Reagan issued an executive order in 1986 creating a drug-free federal workplace. In 1989 the United States Department of Transportation (DOT) developed testing regulations utilizing the five-panel basic urine drug screen. Soon after, the U.S. Supreme Court found that the privacy of individuals was outweighed by public safety. In 1990 DOT testing was amended to include alcohol. Help for those who test positive was inherent in the original executive order but is largely ignored by those who use workplace drug panels today.
Procedure
The collection of urine specimens follow strict "chain of evidence" rules. Unless a special dedicated toilet chamber is used, attendants must directly observe collection. Jackets, backpacks and purses must be left outside the stall. The person giving the specimen initials a seal on the top of the container to prevent substitutions.
Instant five-panel urine tests come in strips or cards that are dipped and give results within minutes. The unreliability of instant testing is problematic; a positive result must be double-checked by a lab, where it is reviewed and verified by a licensed physician.
Individual Panels
The amphetamine panel is designed to detect more than 1,000 nanograms per milliliter (ng/ml) of amphetamine, methamphetamine and dextroamphetamine. Many tests can also detect chemically similar substances such as ecstacy (MDMA).
The cannabinnoids panel is sensitive to THC. A heavy marijuana user could test positive for up to one month. A urine test cannot determine if use is recent, except in relation to subsequent tests that show a drop in ng/ml of urine. Once cannabinnoids are below 50 ng/ml they will no longer show a positive test.
New tests use a few drops of saliva instead of urine and can narrow THC use to the past 24 hours. They are not able to detect benzodiazepines (minor tranquilizers), however.
Heroin, morphine, codeine and opium are opiate drugs. Semisynthetic opiods such as oxycodone (Oxycontin, Percocet) and hydrocodone (Vicodin) are detectable by more sensitive tests.
Limitations
According to John Faye, author of "A Drug Free Workplace," hallucinogens such as LSD are rarely tested for. Synthetic opioids such as Fentanyl and methadone are also exempt from a five-panel drug screen. Alcohol is subject to false positives for diabetics or those with a yeast infection.
Adulteration
Drinking large amounts of fluid dilutes metabolites below detectable amounts but is also easily noted by the lab. Creatinine, a substance in urine, determines if specimens are abnormally diluted or if they contain added water. Faye asserts the use of diuretic herbs or medications can increase the concentration of metabolites in urine.
References
- "The Drug Free Workplace"; John Faye, 2000
- Drug Free Workplace: Nationwide Medical Review
- Entrepreneur: When Will Drug Testing and Treatment Meet? Gary A Enos, June 2009
