Hair test for drugs

The Potential for Bias in Hair Testing for Drugs of Abuse.69... 

THE POTENTIAL FOR BIAS IN HAIR TESTING FOR DRUGS OF ABUSE... 

Kits. Drug tests used for fast, preliminary screening include easy-to-use kits that can test samples of urine, saliva, breath, hair, or sweat. Of these tests, the hair test for drugs is considered to be the most accurate but is still considered to be a preliminary test To confirm preliminary results or to obtain results for legal purposes, a sample of sahva or urine must be sent to a laboratory when a more reliable test such as GG/MS must be performed. It can take three to seven days to obtain the results. Urine drug test kits are less expensive than other tests, provide instantaneous results, and are easy to store. However, because of variations in metabolism rate, there can be a three-day to one-month detection window, making these tests easier to adulterate than the saliva, hair, sweat, or blood tests. 

Sachs H, Kintz P. 1998. Testing for drugs in hair, critical review of chromatographic procedures since 1992. J Chromatogr B 713 147. 

Reuschel and Smith conducted a study in which they measured the concentration of benzoylecgonine in black, brown, blond, and red hair collected from jail detainees. They tested 48 hair samples for drug and 22 tested positive. The concentration of benzoylecgonine in black and brown hair was 5.6 + 5.2 ng/mg of hair in comparison to that in blond and red hair, which was 1.39+ 1.34 ng/mg of hair. However, Reuschel and Smith did not elicit information about prior drug use from individuals, and these results could be attributable to differences in the frequency and extent of drug use. 

Kidwell, D. A. and Blank, D. L., Mechanisms of incorporation of drugs into hair and the interpretation of hair analysis data, in NIDA Research Monograph, Cone, E. J. and Welch, M., Eds., 1994. Su, T. P, Tsai, W. J., Joseph, R., Tsao, L. L, and Cone, E. J., Cocaine binds in a sterospecific, saturable manner to hair a precaution on hair testing for forensic purposes, presented at College on Problems of Drug Dependence, Palm Beach, June 18-23,1994. 

Marsh et al. and Marsh and Evans utilized the DPC morphine-specific RIA to study the effectiveness of wash procedures and self-reporting of drug use. The assay was found to be highly specific, accurate, and precise. Evaluation of hair from drug-free controls produced results <0.3 ng/mg. In the study, the results of segmental hair tests for morphine for a period of 15 months were used to challenge a subject s declaration of heroin abstinence. In similar studies. Marsh and Evans evaluated the effectiveness of the DPC methadone RIA. The assay was also found to be highly specific, accurate, and precise. 

Results of hair tests for abused drugs such as cocaine and opioids can provide useful information regarding drug use. Compared to urine analysis, hair testing provides an extended window of analyte (parent and metabolites) detection which cannot be affected by short periods of abstinence. In addition, collection of hair is considered by most a noninvasive technique, and retesting through a second sample is possible. Also, in contrast to urine, hair is not readily adulterated. 

Testing hair specimens for drugs offers a much broader window for detection than most biological specimens. In fact, hair analysis may provide a good complement to plasma and urine. Hair is easily collected and can be stored without damage. 

The most prominent biological samples used for testing for drugs of abuse are urine, blood, hair, and saliva. Drugs can also be detected in many other biological specimens, such as sweat, vitreous humor, and autopsy material such as liver in general... 

Gaillard, Y., and Pepin, G. (1997) Hair testing for pharmaceuticals and drugs of abuse Forensic and clinical applications. American Clinical Faboratory, 16,18-22. 

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