Testing human hair for drugs of abuse. IV. Environmental cocaine contamination and washing effects

Assessing Hair Decontamination Protocols for Diazepam, Heroin, Cocaine and Δ9-Tetrahydrocannabinol by Statistical Design of Experiments

Prior to toxicological analysis, hair as a matrix requires pre-treatment measures including decontamination, homogenization and extraction. Decontamination is performed to differentiate between drug present from superficial deposition and drug incorporated from systemic distribution following ingestion. There are many methods for decontamination of hair samples, mostly developed by empirically using a traditional "one factor at a time" approach, in which one independent variable at a time is changed to observe the effect on the dependent variable. The goal of the present work was to compare the efficacy of decontamination protocols using statistical "design of experiments" (DoE), which allows for analysis of multiple variables and interactions within a single experiment. Decontamination parameters included identity of aqueous and organic wash solutions, number of sequential aqueous and organic washes, order of aqueous and organic washes, and duration of each wash. DoE studies were completed to identify optimal decontamination conditions for four abused drugs with varying physiochemical properties. For this purpose, drug-free human hair was externally contaminated with diazepam, heroin, cocaine or Δ9-tetrahydrocannabinol. Each analyte was found to have a unique set of decontamination conditions that were most effective. These included three 30-min washes with methanol followed by three with 1% sodium dodecyl sulfide for diazepam, three 30-s washes with dichloromethane followed by one with water for heroin, one 30-s wash with 1% sodium dodecyl sulfate followed by three with dichloromethane for cocaine and three 30-min washes with water followed by one with methanol for Δ9-tetrahydrocannabinol. The results provide proof-of-principle for a DoE approach to identify effective parameters for hair decontamination for a physicochemically diverse group of drugs. The major advantage of DoE is to elucidate combinations of parameters that result in effective removal of surface contamination, a goal that would be challenging to accomplish using a one factor at a time approach.

Hair as a Biological Indicator of Drug Use, Drug Abuse or Chronic Exposure to Environmental Toxicants

In recent years hair has become a fundamental biological specimen, alternative to the usual samples blood and urine, for drug testing in the fields of forensic toxicology, clinical toxicology and clinical chemistry. Moreover, hair-testing is now extensively used in workplace testing, as well as, on legal cases, historical research etc. This article reviews methodological and practical issues related to the application of hair as a biological indicator of drug use/abuse or of chronic exposure to environmental toxicants. Hair structure and the mechanisms of drug incorporation into it are commented. The usual preparation and extraction methods as well as the analytical techniques of hair samples are presented and commented on. The outcomes of hair analysis have been reviewed for the following categories: drugs of abuse (opiates, cocaine and related, amphetamines, cannabinoids), benzodiazepines, prescribed drugs, pesticides and organic pollutants, doping agents and other drugs or substances. Finally, the specific purpose of the hair testing is discussed along with the interpretation of hair analysis results regarding the limitations of the applied procedures.

Police Drug Testing, Hair Analysis, and the Issue of Race Bias

Poice agents have beg to use hair analysis as a drug-screening tool in both officer recruitment and officer monitoring. This has been controversial because of a putative racial bias associated with human hair specimens, especially focused on cocaine. However, little empirical evidence has been offered to substantiate this claim. To asses this issue, Hoffin (1999, p. 613) analyzed recruitment cohort data from a major metropolitan police department ( N - 1,80) for cocaine ad marijuana hair assays, contrasting recruits by race. Hoffman's conclusion, based on comparison of odds ratios and relative rates for positive assy outcomes, was that there was "no evidence that one group (i.e., race) was more adversely affected by hair testing compared to urine testing." This article reports on research seekig to replicate Hoffman's results concerning hair analysis by utilizing a similar analytic approach with a much larger data set ( N - 40,000) and examining a different major metropolitan police department. This research is disnct form the Hoffman study in two ways: The assessment was exclusively of cocaine prevalence, and the subjects were who job applicants but sworn police officers. The findings reported here support Hoffman's conclusion that there is no statically significant race bias attributable to hair analysis, at least as applied to cocaine.

Insights into the Passive Partitioning of Amino Acids and Codeine into Human Hair

Background:

Cells that form hair are among the body's most rapidly dividing cells, with each daughter cell becoming part of the hair shaft as it differentiates and lengthens. It follows that hair might contain concentrations of xenobiotics (environmental chemicals, therapeutic drugs, illicit substances, etc.) reflective of the concentration in blood at the time of division and onset of differentiation of cells that give rise to hair.

Objective:

This study was designed to gain insight into the passive incorporation of xenobiotics into hair.

Methods:

This study focused on the parameters of the passive partitioning of three agents, two water-soluble amino acids (cysteine and glutamine) and codeine into hair. Undamaged black hair from various ethnic groups was incubated in solutions containing the three agents as a function of time and concentration. Hair was washed extensively; time and dose to steady state as well as partitioning coefficients were determined for each agent. Codeine washing with a pH gradient also was carried out.

Results:

Data show that the partitioning coefficient of the agents is linear but not stoichiometric. At low doses passive partitioning into hair is efficient, a 1 minute exposure leading to significant retention. Washing extensively with deionized water, the fluid used for passive partitioning of the test agent, will not reversibly extract all of the agent, regardless of race.

Conclusion:

Hair can effectively absorb and retain agents of the environment, and this retention occurs via mechanisms other than those inherent to an ion exchange column.

Efficacy of scalp hair decontamination following exposure to vapours of sulphur mustard simulants 2-chloroethyl ethyl sulphide and methyl salicylate

Chemical warfare agents are an actual threat and victims' decontamination is a main concern when mass exposure occurs. Skin decontamination with current protocols has been widely documented, as well as surface decontamination. However, considering hair ability to trap chemicals in vapour phase, we investigated hair decontamination after exposure to sulphur mustard simulants methyl salicylate and 2-chloroethyl ethyl sulphide. Four decontamination protocols were tested on hair, combining showering and emergency decontamination (use of Fuller's earth or Reactive Skin Decontamination Lotion RSDL^®). Both simulants were recovered from hair after treatment, but contents were significantly reduced (42-85% content allowance). Showering alone was the least efficient protocol. Concerning 2-chloroethyl ethyl sulphide, protocols did not display significant differences in decontamination efficacy. For MeS, use of emergency decontaminants significantly increased showering efficacy (10-20% rise), underlining their usefulness before thorough decontamination. Our results highlighted the need to extensively decontaminate hair after chemical exposure. Residual amounts after decontamination are challenging, as their release from hair could lead to health issues.

Use of hair testing to determine methadone exposure in pediatric deaths

A case of death attributed to methadone acute poisoning in an infant aged 11 months is reported. A sudden infant death syndrome (SIDS) was suspected, whereas a traumatic cause of death was excluded regarding autopsy findings. Specimens were submitted to a large toxicological analysis, which included ethanol measurement by HS-GC-FID, a targeted screening for drugs of abuse and various prescription drug classes followed by quantification using UPLC-MS/MS methods. Methadone and its metabolite (EDDP) were detected in all the tested fluids, as well as in hair, with a blood concentration of methadone considered as lethal for children (73 ng/mL). The cause of death was determined to be acute "methadone poisoning", and the manner of death was "accidental". A discussion of the case circumstances, the difficulties with the interpretation of toxicological findings in children (blood concentration and hair testing), and the origin of exposure are discussed.

Primary outcome indices in illicit drug dependence treatment research: systematic approach to selection and measurement of drug use end-points in clinical trials

AIMS

Clinical trials test the safety and efficacy of behavioral and pharmacological interventions in drug-dependent individuals. However, there is no consensus about the most appropriate outcome(s) to consider in determining treatment efficacy or on the most appropriate methods for assessing selected outcome(s). We summarize the discussion and recommendations of treatment and research experts, convened by the US National Institute on Drug Abuse, to select appropriate primary outcomes for drug dependence treatment clinical trials, and in particular the feasibility of selecting a common outcome to be included in all or most trials.

METHODS

A brief history of outcomes employed in prior drug dependence treatment research, incorporating perspectives from tobacco and alcohol research, is included. The relative merits and limitations of focusing on drug-taking behavior, as measured by self-report and qualitative or quantitative biological markers, are evaluated.

RESULTS

Drug-taking behavior, measured ideally by a combination of self-report and biological indicators, is seen as the most appropriate proximal primary outcome in drug dependence treatment clinical trials.

CONCLUSIONS

We conclude that the most appropriate outcome will vary as a function of salient variables inherent in the clinical trial, such as the type of intervention, its target, treatment goals (e.g. abstinence or reduction of use) and the perspective being taken (e.g. researcher, clinical program, patient, society). It is recommended that a decision process, based on such trial variables, be developed to guide the selection of primary and secondary outcomes as well as the methods to assess them.

Incorporation of methamphetamine and amphetamine in human hair following controlled oral methamphetamine administration

BACKGROUND

Although hair testing is well established for the assessment of past drug exposure, uncertainties persist about mechanisms of drug incorporation into hair and interpretation of results. The aim of this study was to administer methamphetamine (MAMP) under controlled conditions as a model drug to investigate drug incorporation into human hair.

MATERIAL AND METHODS

Seven volunteers with a history of stimulant use received 4×10 mg (low) doses of sustained release S-(+)-MAMP HCl within 1 week, with weekly head hair samples collected by shaving. 3 weeks later, 4 of them received 4×20 mg (high) doses. After extensive isopropanol/phosphate buffer washing of the hair, MAMP and its metabolite amphetamine (AMP) concentrations were determined in all weekly hair samples by LC-MS-MS in selected reaction monitoring mode with the undeca- and deca-deuterated drugs, respectively, as internal standards (LLOQ, 0.005 ng mg(-1)).

RESULTS

MAMP T(max) occurred from 1 to 2 weeks after both doses, with C(max) ranging from 0.6 to 3.5 ng mg(-1) after the low and 1.2 to 5.3 ng mg(-1) after the high MAMP doses. AMP C(max) in hair was 0.1-0.3 ng mg(-1) and 0.2-0.5 ng mg(-1), respectively, for low and high doses. Highly dose-related concentrations within subjects, but large variability between subjects were observed. MAMP concentrations were above the 0.2 ng mg(-1) cut-off for at least 2 weeks following administration of both low and high doses. The overall AMP/MAMP ratio ranged from 0.07 to 0.37 with a mean value of 0.15 ± 0.07, and a median of 0.13. The percentage of MAMP and AMP removed with the washing procedure decreased with time after administration. A strong correlation was found between area under the curve of MAMP (r(2)=0.90, p=0.00) and AMP (r(2)=0.94, p=0.00) concentrations calculated for the 3-week period following administration and the total melanin concentration in hair. Significant correlations were observed also between C(max) and melanin.

CONCLUSIONS

This study demonstrated that despite large inter-individual differences, the incorporation of MAMP and AMP into hair is dose-related with much of the observed scatter of MAMP and AMP concentrations explained by melanin concentration in hair.

Determining the primary endpoint for a stimulant abuse trial: lessons learned from STRIDE (CTN 0037)

BACKGROUND

No consensus is available for identifying the best primary outcome for substance use disorder trials, making interpretation across trials difficult. Abstinence is the most desirable treatment outcome although a wide variety of other endpoints have been used.

OBJECTIVES

This report provides a framework for determining an optimal primary endpoint and the relevant measurement approach for substance use disorder treatment trials. The framework was developed based on a trial for stimulant abuse using exercise as an augmentation treatment, delivered within the NIDA Clinical Trials Network. The use of a common endpoint across trials will facilitate comparisons of treatment efficacy.

METHODS

Primary endpoint options in existing substance abuse studies were evaluated. This evaluation included surveys of the literature for endpoints and measurement approaches, followed by assessment of endpoint choices against study design issues, population characteristics, tests of sensitivity, and tests of clinical meaningfulness.

CONCLUSION

We concluded that the best current choice for a primary endpoint is percent days abstinent, as measured by the Time Line Follow Back interview conducted three times a week with recall aided by a take-home Substance Use Diary. To improve the accuracy of the self-reported drug use, the results of qualitative urine drug screens will be used in conjunction with the Time Line Follow Back results.

SCIENTIFIC SIGNIFICANCE

There is a need for a standardized endpoint in this field to allow for comparison across treatment studies, and we suggest that the recommended candidate endpoint be considered. However, the study design and goals ultimately must guide the final decision.

Collection of biological samples in forensic toxicology

Forensic toxicology is the study and practice of the application of toxicology to the purposes of the law. The relevance of any finding is determined, in the first instance, by the nature and integrity of the specimen(s) submitted for analysis. This means that there are several specific challenges to select and collect specimens for ante-mortem and post-mortem toxicology investigation. Post-mortem specimens may be numerous and can endow some special difficulties compared to clinical specimens, namely those resulting from autolytic and putrefactive changes. Storage stability is also an important issue to be considered during the pre-analytic phase, since its consideration should facilitate the assessment of sample quality and the analytical result obtained from that sample. The knowledge on degradation mechanisms and methods to increase storage stability may enable the forensic toxicologist to circumvent possible difficulties. Therefore, advantages and limitations of specimen preservation procedures are thoroughfully discussed in this review. Presently, harmonized protocols for sampling in suspected intoxications would have obvious utility. In the present article an overview is given on sampling procedures for routinely collected specimens as well as on alternative specimens that may provide additional information on the route and timing of exposure to a specific xenobiotic. Last, but not least, a discussion on possible bias that can influence the interpretation of toxicological results is provided. This comprehensive review article is intented as a significant help for forensic toxicologists to accomplish their frequently overwhelming mission.

Analytical pitfalls in hair testing

This review focuses on possible pitfalls in hair testing procedures. Knowledge of such pitfalls is useful when developing and validating methods, since it can be used to avoid wrong results as well as wrong interpretations of correct results. In recent years, remarkable advances in sensitive and specific analytical techniques have enabled the analysis of drugs in alternative biological specimens such as hair. Modern analytical procedures for the determination of drugs in hair specimens - mainly by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) - are reviewed and critically discussed. Many tables containing information related to this topic are provided.

Analysis of endogenous cortisol concentrations in the hair of rhesus macaques

Short-term changes in activity of the hypothalamic-pituitary-adrenocortical (HPA) system are routinely assessed by measuring glucocorticoid or metabolite concentrations in plasma, saliva, urine, or feces. However, there are no current methods for determining long-term (i.e., weeks or months) activity of this system. Herein, we describe the development and validation of a simple procedure for measuring cortisol concentrations in the hair of rhesus macaques. This procedure involves two brief isopropanol washes of the hair strands to remove surface contaminants, subsequent powdering of the washed and dried hair, a 24-h methanol extraction followed by evaporation of the solvent and reconstitution of the extract in assay buffer, and finally analysis of the extracted cortisol by a sensitive and specific enzyme immunoassay. Our results confirm the specificity of the procedure for cortisol, show that proximal and distal segments of hair do not differ in their cortisol concentration, and demonstrate that a significant and prolonged stressful experience produces a significant increase in hair cortisol. This new procedure should be valuable for assessing baseline HPA activity in nonhuman primates (and, with appropriate validation, in other species as well) over relatively long periods of time, and also for monitoring chronic stress that might be associated with various experimental manipulations.

New trends in hair analysis and scientific demands on validation and technical notes

This review focuses on basic aspects of method development and validation of hair testing procedures. Quality assurance is a major issue in drug testing in hair resulting in new recommendations, validation procedures and inter-laboratory comparisons. Furthermore recent trends in research concerning hair analysis are discussed, namely mechanisms of drug incorporation and retention, novel analytical procedures (especially ones using liquid chromatography-mass spectrometry (LC-MS) and alternative sample preparation techniques like solid-phase microextraction (SPME)), the determination of THC-COOH in hair samples, hair testing in drug-facilitated crimes, enantioselective hair testing procedures and the importance of hair analysis in clinical trials. Hair testing in analytical toxicology is still an area in need of further research.

Removing and identifying drug contamination in the analysis of human hair

The procedure used in this laboratory for removing and identifying contamination of hair specimens with drugs is demonstrated by its application to hair contaminated by various experimental models. The models include soaking; coating with drug followed by sweat conditions for 6 h; and soaking in a very high concentration of cocaine followed by storage and multiple shampoo treatments. A multi-part wash procedure along with a wash criterion is applied to all samples containing drug above the cutoff. The failure of the wash criterion is a signal that the sample may be positive due to contamination rather than use, and in the absence of other over-riding evidence, the sample would be considered to be negative for drug use. This Wash Criterion has also been tested with hair from subjects demonstrated to be drug users by one or more drug-positive urines; in these studies, all hair samples from demonstrated users passed the Wash Criterion test.

In Vitro Contamination of Hair by Marijuana Smoke

Background: The deposition of cannabinoids on/into hair from environmental smoke can be considered as a potential source of drug findings in hair. We studied external uptake of cannabinoids from marijuana smoke, investigating possible influencing factors on drug uptake and the efficiency of decontamination procedures.

Methods: Strands of a natural hair sample were moistened with water, greased with sebum or sebum/sweat, or bleached or permed. Treated and untreated samples were exposed to marijuana smoke for 60 min. Aliquots of each hair strand were either kept unwashed or were washed with methanol, dichloromethane, or 5 g/L dodecyl sulfate in water. Cannabinoid concentrations in unwashed and washed hair samples, as well as in air samples collected from the exposure chamber and in the marijuana sample being combusted, were quantified by gas chromatography–mass spectrometry or gas chromatography.

Results: Cannabinoids were deposited on the hair fibers from marijuana smoke. Cannabinoid concentrations were dependent on air concentration and hair pretreatment. Uptake was less in untreated than in pretreated hair. Concentrations were increased in damp hair, but were even higher in greased hair. There was no significant difference in concentration between bleached and permed strands. External contaminants were completely removed by washing with methanol and dichloromethane in untreated hair only. Washing with dodecyl sulfate in water was insufficient in all cases.

Conclusions: Exposures of hair to marijuana smoke yields detectable cannabinoids depending on concentrations in the air, hair care habits, and cosmetic treatment. Environmental marijuana smoke exposure may produce false-positive or falsely increased test results in hair.

Determination of drugs of abuse in hair: evaluation of external heroin contamination and risk of false positives

One of the most controversial point regarding the validity of hair testing is the risk of false positive due to external contamination. The aim of our experience is to verify if a 5 consecutive days contamination with a small amount of a powdered mixture of heroin hydrochloride and acetylcodeine hydrochloride (10:1 w/w) will last sufficiently long to make a contaminated subject indistinguishable from active users, and if normal washing practices together with the decontamination procedure are sufficient to completely remove the external contamination. Our results suggest that decontamination procedures are not sufficient to remove drugs penetrated into hair from external source. In fact, all contaminated subjects were positive for opiates (heroin, 6-MAM, morphine, acetylcodeine and codeine) for at least 3 months. Significant 6-MAM concentrations (>0.5 ng/mg) were found in each subject until 6th week. Further, 6-MAM/morphine ratio were always above 1.3.

Hair as a biomarker for exposure to tobacco smoke

This article provides an overview of the hair nicotine biomarker for assessment of exposure to tobacco smoke, with emphasis on environmental tobacco smoke (ETS). Measurement of nicotine in hair can be an informative tool for research looking at ETS and related illnesses. There are still unresolved issues in relation to this biomarker such as influence of hair treatment, hair colour, and growth rate on nicotine levels in hair, which need to be addressed in order to further refine this biomarker for exposure assessment. Nevertheless, hair nicotine promises to be a valid and reliable measure of longer term exposure that can be readily applied in epidemiological studies of exposure to tobacco smoke, and more specifically ETS, and its risk to health.

Hair testing for drugs of abuse: evaluation of external cocaine contamination and risk of false positives

In some laboratories hair testing may be the main method for the evaluation of individual's drug history, however, compelling evidence supports the possibility that the presence of a small amount of drug in hair can derive from external contamination. The aim of the present study is to verify if a single external contamination with a small amount of cocaine will last sufficiently long to make a contaminated subject indistinguishable from active users, and if normal washing practices together with the decontamination procedures are sufficient to completely remove the external contamination. The results obtained using the decontamination methods suggested in literature demonstrate that significant concentrations of cocaine (>1 ng/mg) and moderate quantities of benzoylecgonine (generally <0.5 ng/mg) are still detectable up to 10 weeks after contamination. These results question the reliability of hair testing. In fact, even using the most sophisticated decontamination procedures it is not possible to distinguish a drug-contaminated subject from an active user. Thus, while a negative result excludes both chronic use and "contact" with drugs, a positive result cannot and must not be interpreted as a sure sign of drug addiction, but should be further confirmed by urine analysis.

Evaluation of the addiction history of a dead woman after exhumation and sectional hair testing

In Greece, sectional hair analysis, in addition to clinical examination, has been used as a valuable tool for the confirmation of a person's history of drug use. The present report concerns the toxicologic analysis of the exhumed remains and hair samples of an 18-year-old woman. Postmortem toxicologic analysis of blood and urine confirmed recent opiate and cannabis use and indicated that death was associated with heroin abuse. Several months later, the woman's family asked for exhumation and reexamination of the body, insisting that the cause of death was homicide. The investigating judge ordered exhumation and new medicolegal examination of the body. The investigation of the drug profile along the hair shaft was undertaken by analyzing hair sections 1 cm from the hair root for morphine, 6-monoacetylmorphine, heroin, and cannabinoids. The total lengths of the hair samples ranged from 8 to 11 cm. The total morphine levels in the hair sections corresponding to the 3-month period before death were significantly lower (1.5-2.85 ng/mg) than those of the 4- to 10-month period before death (7.4-14.8 ng/mg). An interpretation of these results may be occasional drug use (with considerable attenuation of use during the last 3 months before death). Decrease of tolerance to heroin caused by abstinence and relapse in use could have been the cause of death.

Regulatory problems caused by contamination, a frequently overlooked cause of veterinary drug residues

The occurrence of violative residues of veterinary medicines and other, unauthorised, drugs in food of animal origin is an issue of popular concern within the European Union. Violations can occur as a result of improper use of a licensed product or through the illegal use of an unlicensed substance. However, a "violative" analytical result does not necessarily mean that abuse has occurred. Contamination of animal feedingstuffs, environmental contamination and animal-to-animal transfer of drugs can also cause residue violations. This paper reviews these inadvertent causes of residues violations in food, and includes data generated using chromatographic and non-chromatographic methods of analysis.

Segmental analysis for cocaine and metabolites by HPLC in hair of suspected drug overdose cases

Hair samples of eight postmortem cases were analyzed in segments of 1 to 3 cm for cocaine, benzoylecgonine and cocaethylene. Samples were prepared for analysis by digestion in 0.1 M HCl and subsequent extraction with mixed-mode solid-phase extraction columns. Measurement was made by reversed-phase, narrow-bore HPLC and fluorescence detection using two laboratory-made internal standards. The concentrations were in the region of 0.29-316 ng/mg of hair for cocaine, 0.43-141 ng/mg of hair for benzoylecgonine and 0.93-1.83 ng/mg of hair for cocaethylene. All eight investigated cases had cocaine-positive segments. In six of the cases, all segments were positive, suggesting regular cocaine use and two showed in-between negative segments indicating an interruption or a change of the abuse intensity. The results showed a second, remarkable observation, i.e. enormous concentration differences (factor >150) for both cocaine and benzoylecgonine between the different subjects. Furthermore, interindividual cocaine/benzoylecgonine ratios ranged from 0.02 to 8.43. We believe these observations could in part be attributed to both some of the still existing limitations in the analytical approach(es), especially the mandatory hair washing steps, and in our still too limited knowledge of the hair incorporation processes. Nevertheless, in some cases, segmental analysis proved to be an important tool to distinguish, together with postmortem examination, deadly chronic abuse from single acute drug overdosage.

Evidence for bias in hair testing and procedures to correct bias

A number of in vitro experiments show that different hair samples incorporate differing amounts of drugs under identical conditions. Incorporation of cocaine and morphine tends to be correlated with race, in that the hair of African American females incorporates higher concentrations of cocaine than does the hair of Caucasian males or females. Extrapolation of these data into populations has been fraught with difficulties because the dosages of drugs and their use patterns are unknown. Cosmetic treatments and hygiene alter drug binding, which must be considered in comparing populations because cosmetic treatments are often group dependent. Four reasons are proposed that account for the uptake and retention of drugs by hair and that may differ among groups: (1) permeability and other characteristics of the hair due to genetic influences, (2) cosmetic hair treatments and hair care habits (which may be culturally influenced), (3) drug removal during personal hygiene, and (4) manner and route of drug administration which can affect passive exposure to residual drugs in the environment. The data supporting bias in hair testing are reviewed and methods are proposed that use either the uptake of dyes or the incorporation of drug homologs to reduce bias.

Therapeutic drug monitoring for methadone: scanning the horizon

The initial assessment and subsequent monitoring of compliance in methadone treatment programmes are excessively reliant on the accuracy of self-report from opiate addicts themselves. Given the central position of methadone treatment in the therapeutic options currently available and with the increasing number of opiate addicts requiring treatment, improved methods of judging optimal methadone treatment are required. This paper explores the possible future options for assessing the adequacy of methadone prescribing from the analysis of methadone levels in urine, blood, hair and saliva. The particular promise of plasma therapeutic drug monitoring for methadone is explored, accompanied by an account of the state of the art at the time of writing.

Gas chromatographic-mass spectrometric quantitation of dextropropoxyphene and norpropoxyphene in hair and whole blood after automated on-line solid-phase extraction. Application in twelve fatalities

After conversion of norpropoxyphene (NP) to its corresponding amide, dextropropoxyphene (DP) and NP are extracted from 1 ml of blood or 50 mg of powdered hair, on C18 cartridges and eluted using methanol containing 0.5% acetic acid. Automated extraction is conducted on-line with automated device, starting from buffered and centrifuged sample. After extraction, the dried residue is reconstituted with 40 microl of methanol, and then injected in a gas chromatograph at 250 degrees C. Quantitation is carried out by gas chromatography-mass spectrometry in the selected-ion monitoring mode, lidocaine being the internal standard. The method gave relative standard deviations lower than 6.2% in whole blood, and 6.0% in hair for the entire range of calibration from 0.5 to 10 microg/ml in blood and from 1 to 20 ng/mg in hair of both compounds. Limits of detection in blood and hair for DP are, respectively, 0.07 microg/ml and 0.05 ng/mg, whereas the respective limits of detection in whole blood and hair for NP are 0.09 microg/ml and 0.04 ng/mg. The present method was used for one year in our laboratory. Postmortem concentrations of DP in blood ranged from 1.6 to 44.0 microg/ml (mean=9.8microg/ml, n = 12) and are comparable to those found in the literature. Out of 30 hair samples from people who died from heroin overdose, 13 were positive both for DP and NP with concentrations ranging from 0.2 to 27.4 ng/mg (mean 8.7 ng/mg) for DP and 0.3 to 68.9 ng/mg (mean 24.1 ng/mg) for NP.

Detection of drug use during pregnancy

Several methods of drug testing are efficacious in identifying and monitoring drug use during pregnancy. Urine screening remains the most commonly used method despite the limited period during which drugs can be detected. Hair has been recognized as a possible alternate test specimen, but wider acceptance of hair testing must await better understanding of drug disposition in hair, answers to the issues relating to interpretation, and the development of less demanding laboratory techniques. Regardless of the matrix used, proper interpretation of the results of drug testing requires familiarity with the sensitivity, specificity, and limitations of the laboratory methodologies employed. Moreover, unconfirmed positive results may actually be false-positives and must be interpreted with caution, particularly if they are the basis for major clinical decisions.

Distinguishing passive contamination from active cocaine consumption: assessing the occupational exposure of narcotics officers to cocaine

Hair analysis has been used in probationary and parole populations to monitor for cocaine use, but only in very limited settings or circumstances. Its wider adoption has been limited by questions regarding the ability to distinguish environmental contamination of hair via casual contact from actual ingestion. To evaluate this capability we sought to identify persons routinely exposed to cocaine, who were not cocaine users. Undercover narcotics officers engaged in cocaine-centered enforcement activities and evidence room clerks who have no history of cocaine use were identified as an appropriate example population. Thirty-six active undercover officers and four evidence technicians were asked to voluntarily submit hair samples for analysis. Additionally two cocaine contaminated (aqueous soaked), three negative control samples, and hair from a self-reported crack smoker were also blindly submitted to the testing laboratory. The hair samples were washed and after washing, enzyme digested. The wash solutions and hair digest were each analyzed for the presence of cocaine. The results indicate that nearly every person had trace amounts of cocaine contamination in the wash fraction, and one person had cocaine present in their hair digest That person, when retested, was a negative. The laboratory correctly identified and characterized the contaminated, negative, and positive controls. The study concludes that the findings support the capability of hair analysis to distinguish cocaine use from exposure under normal field conditions. The study results indicate that cocaine-abstinent persons who are in chronic, casual environmental contact with cocaine are not likely to test hair positive for cocaine using the analysis protocols followed in this project. The study also indicates that passive microingestion of cocaine needs to be considered when examining persons who are in cocaine intensive environments.

Determination of opiates in hair. Effects of extraction methods on recovery and on stability of analytes

In order to evaluate (i) the recovery of extraction of opiates from authentic hair samples and (ii) the extent of hydrolysis of acetylated opiates (6-acetylmorphine, acetylcodeine) occurring during sample preparation, three different methods of extraction commonly used for opiates have been compared. To this purpose a sample consisting of a pool of hair collected from several heroin overdose cases has been submitted alternately to (A) digestion in 2 M NaOH at 80 degrees C for 1 h (n = 5), (B) incubation in 0.1 M HCl at 45 degrees C for 18 h (n = 5) and (C) incubation in methanol at 37 degrees C for 18 h (n = 5). After pH adjustment of the different incubation media to 7-8, analytes have been isolated by means of SPE using Bond Elut certify columns and derivatized with MSTFA. Analyses have been performed by either GC-MS in the selected ion monitoring mode or, omitting SPE, by radioimmunoassay. The extent of hydrolysis of 6-acetylmorphine to morphine and of acetylcodeine to codeine have been determined by submitting blank hair samples spiked with the acetylated analytes to the different extraction methods and measuring the amount of morphine and codeine formed. Both the recovery of extraction of the total morphine fraction (6-acetylmorphine + morphine) and the rate of hydrolysis of 6-acetylmorphine were found to be in the order: A > B > C. Similar results were obtained for the total codeine fraction (acetylcodeine + codeine). These results clearly indicate that: (i) the concentration of opiates measured in hair depends on the extraction method used; (ii) ratios between different analytes (e.g. 6-acetylmorphine vs. morphine) may reflect the rate of hydrolysis during sample preparation rather than different types of exposure to opiates.

Detection of intrauterine illicit drug exposure by newborn drug testing

Identification of intrauterine drug-exposed newborns with toxicological screening may have benefits including close follow-up of the infant by both medical and social services. Applying specific written guidelines to select newborns for drug testing decreases bias and protects the physicians and hospitals involved. All drugs reported as positive should be confirmed by an appropriate second test. Urine and meconium testing are the best current options for identifying drug-exposed neonates. Urine testing sensitivity is low because of problems encountered in urine collections and the high thresholds used in current urine assays. The disadvantage to meconium testing is the increased labor and time required to work with this material. Testing of newborn hair is unlikely to be widely used until technically less demanding assays become available. Testing of amniotic fluid or gastric lavage is still in the developmental stages. Adopting lower urine assay thresholds for newborn samples would increase sensitivity and would be an appropriate modification of current methodologies.

Mechanisms of drug incorporation into hair

Hair testing for drugs of abuse is a developing technology that offers the possibility of longer detection times than is commonly obtained with urine or blood analysis. There are many uncertainties concerning how drugs enter hair and factors that affect drug deposition and residence in hair. Possible routes of drug entry include diffusion from blood, sweat, sebum, and skin and entry from the environment. Evidence is reviewed regarding the importance of each of these routes as possible contributors to drug deposition in hair. Binding to specific sites in hair may involve both electrostatic forces and weaker attractions, such as van der Waals forces. Melanin and protein constituents of hair may serve as binding sites. Recent in vitro studies suggest that the color of hair or melanin content may be the major determinant of cocaine binding and, consequently, may result in color or ethnic bias in hair testing.

Hair analysis as evidence in forensic cases

The analysis of hair for drugs of abuse is a powerful tool useful in answering questions that cannot be solved by the detection of drugs in body fluids, e.g., blood, urine, or saliva. The most frequent forensic investigations occur in cases where narcotics laws are offended and in questions of criminal responsibility where the chronic use of a drug is an issue. In the list of drugs of abuse, heroin, cocaine, amphetamine, and cannabis are the drugs of abuse that are most frequently involved in judicial inquiries.