Influence of the cosmetic treatment of hair on drug testing

Abstract

An important issue of concern for drug analysis in hair is the change in the drug concentration induced by the cosmetic treatment of hair. The products used for this treatment are strong bases and they are expected to cause hair damage. As a result drugs may be lost from the hair matrix or, under conditions of environmental contamination, be more easily incorporated into the hair matrix. We investigated the effects of cosmetic treatment in vivo by analysing hair samples selected from people who had treated their hair by bleaching or dyeing before sample collection. All of the subjects admitted a similar drug consumption during the time period for which the strands were analysed. Samples were viewed under a microscope to establish the degree of hair damage. Treated and untreated portions from each lock of hair were then selected, separated and analysed by standard detection procedures for cocaine, opiates, cannabinoids and nicotine. In all cases the drug content in hair that had undergone cosmetic treatment decreased in comparison to untreated hair. The majority of the mean differences were in the range of 40%-60% (cocaine, benzoylecgonine, codeine, 6-acetylmorphine and THC-COOH). For morphine the mean difference was higher than 60%, and two cases (THC and nicotine) differed by approx. 30%. These differences depended not only on the type of cosmetic treatment, as bleaching produced higher decreases than dyeing, but also on the degree of hair damage i.e. the more damaged the hair, the larger the differences in the concentration levels of drugs.

Determinants of Hair Nicotine Concentrations in Nonsmoking Women and Children: A Multicountry Study of Secondhand Smoke Exposure in Homes

“…Chemical hair treatments were associated with reduction in hair nicotine levels by a factor of 0.9 (95% CI, 0.7-1.2) after controlling for SHS exposure levels, age, and other sociodemographic characteristics of nonsmoking women (Supplement Table S2). This finding was comparable with the experimental result of Jurado et al (40), who reported an average decrease of 30% in hair nicotine concentrations after bleaching naturally colored hair samples among eight French smokers. Pichini et al (41) found that hair nicotine concentrations were affected by treatment (dyes, permanent wave, and hydrogen peroxide), but the results were not reproducible.…”

Paraxanthine/Caffeine Concentration Ratios in Hair: An Alternative for Plasma-Based Phenotyping of Cytochrome P450 1A2?

“…Here, no influence of hair color on paraxanthine/caffeine ratios was found. Furthermore, it is known that cosmetic treatment of hair may decrease drug concentrations [33]. However, in our population, cosmetic hair colouring did not affect measured ratios in hair.…”

Death after excessive propofol abuse

“…It is well known that the results of hair analysis have to be assessed with care [29,30,31] By analysing hair segments we could prove that the propofol abuse of the male nurse was not an excessive one-off abuse but an increasing cronic one. A similar pattern of excessive abuse was evident in the case of an anaesthesiologist who first abused and then was addicted to propofol for about a year.…”