The dependence of the incorporation of methamphetamine into rat hair on dose, frequency of administration and hair pigmentation

Segmental Analysis of R/S-Methamphetamine and R/S-Amphetamine in Abusers' Head Hair

In this study, the relationships between the concentrations of R/S-methamphetamine (MA) and its metabolite R/S-amphetamine (AP), the AP/MA ratio in hair samples, and MA dependence were investigated by performing segmental hair analysis in MA users. Authentic hair samples collected from 10 chronic MA abusers were cut into 1-cm sections (a total of 120 segments). The concentrations of MA and AM enantiomers were quantitatively measured by the LC-MS-MS method. The S-MA concentrations ranged from 1.17 to 256.41 ng/mg and the S-AP concentrations ranged from 0.11 to 23.31 ng/mg in the 120 segments. S-MA and S-AP were the most common analytes identified in hair; no R-MA or R-AP was found. The S-AP/S-MA ratios ranged from 0.03 to 0.32, indicating that the subjects primarily consumed S-MA rather than R-MA or AP. The S-AP/S-MA ratios in the long hair of all chronic MA abusers showed some variation, but there was an overall trend of gradual increase from the distal to the proximal end. This trend was independent of the drug concentrations. Therefore, we could conclude that the AP/MA ratios increased with the duration of MA abuse, and a higher AP/MA ratio suggested high MA dependence. There was no chiral conversion of MA or AP in the hair matrix. The segmental hair analysis showed that all subjects continuously used S-MA, and some users showed an increase in drug dose or the frequency of use.

Levetiracetam concentration in hair is associated with the time schedule of administration: Study on rats

Measurement of hair drug content may be a reliable biomarker of the history of drug exposure, allowing to assess patient long-term compliance. Studies on correlations between antiepileptic drugs intake and their hair contents are limited. The aim of the study was to determine the association between the history of levetiracetam administration and its content in rat hair in controlled laboratory conditions. Additionally, the effects of levetiracetam on hair growth rate and body-weights were examined. Three groups of 12 rats each were exposed to different schedules of levetiracetam administration (10 mg/kg i.p.: every 24, 48 and 72 hours) for 30 days. The control group received daily saline injection. Levetiracetam concentrations in hair were assessed by validated LC-MS/MS method. The mean hair concentrations were as follows: 300 (±100), 170 (±60) and 130 (±80) ng/mg for rats receiving levetiracetam every 24, 48 and 72 hours, respectively. The levetiracetam accumulation in the hair was correlated with the total number of doses received (r = .699, P < .001). Levetiracetam did not affect the hair growth rate and rat body-weight. The concentration of levetiracetam measured in rat hair represents a reliable marker. It may reflect the adherence to levetiracetam treatment; however, further studies on human beings are needed.

Role of hair pigmentation in drug incorporation into hair

Hair analysis has notably expanded its application as a bio-monitor for drug or toxicant exposure. Hair pigmentation is proposed as a major factor affecting drug incorporation into hair; however, the mechanisms underlying the incorporation of drugs into hair are still unclear. In the present study, the effect of hair pigmentation on drug incorporation into hair was examined using rats carrying hair with different melanin status and human cells (SK-Mel-28 cells, HaCaT cells and the co-cultured HaCaT cells with SK-Mel-28 cells) representing the main pigmentary unit in hair. Tramadol, a synthetic opioid analgesic, was selected as a model drug. The distribution of tramadol and its phase I (O-desmethyltramadol [ODMT], N-desmethyltramadol [NDMT] and N,O-didesmethyltramadol [NODMT]) and phase II metabolites (ODMT-glucuronide and NODMT-glucuronide) was investigated in non-pigmented and pigmented hair from Long-Evans rats. Moreover, the incorporation levels of ODMT and ODMT-glucuronide were compared in hair cells. The concentrations of tramadol and its phase I metabolites were significantly higher in pigmented rat hair while those of phase II metabolites did not showed any consistent significant difference depending on the status of hair pigmentation. ODMT was taken up to a greater extent than ODMT-glucuronide by SK-Mel-28 cells, HaCaT cells and the co-cultured HaCaT cells with SK-Mel-28 cells. Notably, the incorporated level of ODMT was higher in SK-Mel-28 cells than HaCaT cells and the concentration difference of ODMT was significantly larger than that of ODMT-glucuronide. This study clearly demonstrated that hair pigmentation played a role as a facilitating factor for the incorporation of basic compounds and provided insight into the drug incorporation process into hair.

Exposures associated with clandestine methamphetamine drug laboratories in Australia

The clandestine manufacture of methamphetamine in residential homes may represent significant hazards and exposures not only to those involved in the manufacture of the drugs but also to others living in the home (including children), neighbours and first responders to the premises. These hazards are associated with the nature and improper storage and use of precursor chemicals, intermediate chemicals and wastes, gases and methamphetamine residues generated during manufacture and the drugs themselves. Many of these compounds are persistent and result in exposures inside a home not only during manufacture but after the laboratory has been seized or removed. Hence new occupants of buildings formerly used to manufacture methamphetamine may be unknowingly exposed to these hazards. Children are most susceptible to these hazards and evidence is available in the literature to indicate that these exposures may result in immediate and long-term adverse health effects. The assessment of exposure within the home can be undertaken by measuring contaminant levels or collecting appropriate biological data from individuals exposed. To gain a better understanding of the available data and key issues associated with these approaches to the characterisation of exposure, a review of the published literature has been undertaken.

Relationship between methamphetamine use history and segmental hair analysis findings of MA users

The aim of this study was to investigate the relationship between methamphetamine (MA) use history and segmental hair analysis (1 and 3cm sections) and whole hair analysis results in Korean MA users in rehabilitation programs. Hair samples were collected from 26 Korean MA users. Eleven of the 26 subjects used cannabis with MA and two used cocaine, opiates, and MDMA with MA. Self-reported single dose of MA from the 26 subjects ranged from 0.03 to 0.5g/one time. Concentrations of MA and its metabolite amphetamine (AP) in hair were determined by gas chromatography mass spectrometry (GC/MS) after derivatization. The method used was well validated. Qualitative analysis from all 1cm sections (n=154) revealed a good correlation between positive or negative results for MA in hair and self-reported MA use (69.48%, n=107). In detail, MA results were positive in 66 hair specimens of MA users who reported administering MA, and MA results were negative in 41 hair specimens of MA users who denied MA administration in the corresponding month. Test results were false-negative in 10.39% (n=16) of hair specimens and false-positive in 20.13% (n=31) of hair specimens. In false positive cases, it is considered that after MA cessation it continued to be accumulated in hair still, while in false negative cases, self-reported histories showed a small amount of MA use or MA use 5-7 months previously. In terms of quantitative analysis, the concentrations of MA in 1 and 3cm long hair segments and in whole hair samples ranged from 1.03 to 184.98 (mean 22.01), 2.26 to 89.33 (mean 18.71), and 0.91 to 124.49 (mean 15.24)ng/mg, respectively. Ten subjects showed a good correlation between MA use and MA concentration in hair. Correlation coefficient (r) of 7 among 10 subjects ranged from 0.71 to 0.98 (mean 0.85). Four subjects showed a low correlation between MA use and MA concentration in hair. Correlation coefficient (r) of 4 subjects ranged from 0.36 to 0.55. Eleven subjects showed a poor correlation between MA use and MA concentration in hair. Correlation between MA use and MA concentration in hair of remaining one subject could not be determined or calculated. In this study, the correlation between accurate MA use histories obtained by psychiatrists and well-trained counselors and MA concentrations in hair was shown. This report provides objective scientific findings that should considerably aid the interpretation of forensic results and of the results of trials related to MA use.