Many organizations require drug testing for a myriad other reasons, whether job applicants or current employees. But there are problems with testing. For example, urine drug tests may yield false positives, meaning the person tests positive but is no drug abuser. some individuals who abuse drugs receive a false negative on their drug test. An organization may then have an unwarranted sense of security. Other issues include the drug testing of children and adolescents, for example, those participating in sports. The American Academy of Pediatrics opposes drug testing of children.
False Positives
Individuals taking common prescribed or over-the-counter medications may receive a false positive urine drug test result. This can be devastating to an individual. A more sophisticated urine test could refute the presence of the drug but the agency ordering the test may not wish to pay for further testing.
According to Stacy E. F. Melanson, M.D., PhD and colleagues in their 2006 article for the "Archives of Pathology and Laboratory Medicine," some examples of drugs which may cause false positives are ranitidine or Zantac—a common medication for heartburn and ulcer pain, which may give a false positive for amphetamines. They also noted in their study of patients taking promethazine—Phergan, that 36 percent received a false positive result for amphetamines on a urine drug test.
According to Tai C. Kwong, PhD. in his chapter on clinical false positive tests results in the "Handbook of Drug Monitoring Methods," individuals may test positive for cocaine, marijuana and phenyclidine-—PCP—from common drugs. For example, use of the Vicks Inhaler may yield a false positive for methamphetamine.
False Negatives
Individuals sometimes receive a false negative on a drug test, often because the substance does not reach the level that would indicate drugs are present, perhaps because the individual has not used drugs for a few days. Hair tests can provide past drug use information for months after it was used, versus the several days result given with a drug test, points out Pascal Kintz in his chapter in "Forensic Science and Medicine." But many laboratories are not set up for hair testing.
Testing Children
In 2006, the Committee on Substance Abuse and Council on School Health of the American Academy of Pediatrics reaffirmed their 1996 position opposing drug testing children and adolescents at school or at home, publishing their reasons in Pediatrics in 2007. They continue to hold this view although the U.S. Supreme Court held in 2002 school drug testing is constitutional.
According to these experts, research has not linked drug testing with a decrease in drug use. In addition, laboratory testing for drugs can be complex and few schools are set up to provide tests that manage careful control of the student's urine so it isn't mixed up with another child's urine. They note that it is embarrassing for the student to be directly observed urinating. The experts also noted home tests promoted to parents are problematic because parents may be unaware of false positives and may not interpret results properly.
References
- "Archives of Pathology and Laboratory Medicine"; Reduced Interference by Phenothiazines in Amphetamine Drug of Abuse Immunoassays; Stacy E. F. Melanson, M.D., PhD, et al.; December 2006
- "Clinical False-Positive Drug Test Results" in Handbook of Drug Monitoring Methods; Tai C. Kwong, PhD
- "Pediatrics"; Testing for Drugs of Abuse in Children and Adolescents; Committee on Substance Abuse and Council on School Health; March 2007
- "Drug Testing in Hair" in Forensic Science and Medicine; Pasal Lintz
