Immunoassay evidence for fentanyl in hair of surgery patients

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.

Quantitative determination of fentanyl in newborn pig plasma and cerebrospinal fluid samples by HPLC-MS/MS

In this study, a selective and sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method requiring low sample volume (≤100 μL) was developed and validated for the quantitative determination of the opioid drug fentanyl in plasma and cerebrospinal fluid (CSF). A protein precipitation extraction with acetonitrile was used for plasma samples whereas CSF samples were injected directly on the HPLC column. Fentanyl and (13) C6 -fentanyl (Internal Standard) were analyzed in an electrospray ionization source in positive mode, with multiple reaction monitoring (MRM) of the transitions m/z 337.0/188.0 and m/z 337.0/105.0 for quantification and confirmation of fentanyl, and m/z 343.0/188.0 for (13) C6 -fentanyl. The respective lowest limits of quantification for plasma and CSF were 0.2 and 0.25 ng/mL. Intra- and inter-assay precision and accuracy did not exceed 15%, in accordance with bioanalytical validation guidelines. The described analytical method was proven to be robust and was successfully applied to the determination of fentanyl in plasma and CSF samples from a pharmacokinetic and pharmacodynamic study in newborn piglets receiving intravenous fentanyl (5 µg/kg bolus immediately followed by a 90-min infusion of 3 µg/kg/h).

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.

Evidence of addiction by anesthesiologists as documented by hair analysis

Chemical dependency is a disease that can affect all professions. Among the health care professionals, anesthesiologists represent a specific group. Numerous factors have been proposed to explain the high incidence of drug abuse among anesthesiologists. These include: easy access to potent drugs, particularly narcotics, highly addictive potential of agents with which they are in contact, and easy diversion of these agents since only small doses will initially provide an effect desired by the abuser. Opioids are the drugs of choice for anesthesiologists, and among them fentanyl and sufentanil are the most commonly used. Alcohol is mostly abused by older anesthesiologists. Propofol, ketamine, thiopental and midazolam are also abused. In fact, all but quaternary ammonium drugs can be observed. Signs and symptoms of addiction in the hospital workplace include: unusual changes in behavior, desire to work alone, refusal of lunch relief or breaks, volunteer for extra cases, call, come in early and leave late, frequent restroom breaks, weight loss and pale skin, malpractice, behind on charts .... Toxicological investigations are difficult, as the drugs of interest are difficult to test for. In most cases, half-lives of the compounds are short, and the circulating concentrations weak. It is, therefore, necessary to develop tandem mass spectrometry procedures to satisfy the criteria of identification and quantitation. In most cases, blood and/or urine analyses are not useful to document impairment, as these specimens are collected at inadequate moments. Hair analysis appears, therefore, as the unique choice to evidence chronic exposure. Depending the length of the hair shaft, it is possible to establish an historical record, associated to the pattern of drug use, considering a growth rate of about 1cm/month. An original procedure was developed to test for fentanyl derivatives. After decontamination with methylene chloride, drugs are extracted from the hair by liquid/liquid extraction after incubation in pH 8.4 phosphate buffer. Fentanyl derivatives are analyzed by GC-MS/MS. The following cases are included in this paper: Case 1: 50-year-old anesthetist, positive for fentanyl (644 pg/mg); Case 2: 42-year-old anesthetist, positive for fentanyl (101 pg/mg) and sufentanil (2 pg/mg); Case 3: 40-year-old anesthetist, positive for codeine (210 pg/mg), alfentanil (30 pg/mg) and midazolam (160 pg/mg); Case 4: 46-year-old nurse, found dead, positive for alfentanil (2 pg/mg) and fentanyl (8 pg/mg). In these cases, the combination of an alternative specimen (hair) and hyphenated analytical techniques (tandem mass spectrometry) appears to be a pre-requisite.

Potentiometric determination of fentanyl in pharmaceutical formulations

A poly (vinyl chloride) membrane electrode with dibutyl phthalate as plasticizer based on the fentanyl-phosphotungstate ion-association complex as ion-exchange site for the determination of fentanyl citrate in injections was developed. A linear response for 1 x 10(-5)-1 x 10(-2) mol dm(-3) drug with a slope of 55.9 +/- 0.4 mV per decade was established. The optimum pH range was 1-7. The lower detection limit was 5.43 x 10(-6) mol dm(-3) fentanyl citrate (1.827 microg cm(-3), 2.33 x 10(-6) mol dm(-3) fentanyl). There were negligible interference from a number of inorganic cations, structural analogues, and some common drug additives in injections. The electrode proposed had been successfully applied to determine fentanyl citrate in injections. The results correlated well with those obtained by the United States Pharmacopoeia standard procedure.

Construction and performance characteristics of new fentanyl-selective plastic membrane electrode

The construction and performance characteristics of an ion-selective electrode for fentanyl-drug cation, based on an ion-pair complex with tetrakis[3,5-bis-(trifluoromethyl)phenyl]borate anion in a PVC matrix were studied. A linear response for 1 x 10(-5) mol dm-3 to 1 x 10(-2) mol dm-3 drug with a slope of 57.9 +/- 0.5 mV/decade was established. The optimum pH range was 2 to 6. The lower detection limit was 6.29 x 10(-6) mol dm-3 fentanyl citrate (2.1165 micrograms cm-3 fentanyl). There were negligible interferences from a number of inorganic cations, structural analogues, and some common drug additives in injections. The electrode proposed has been successfully applied to determine fentanyl citrate in injections. The results correlated well with those obtained by the United States Pharmacopoeia standard procedure.

Hair analysis for abused and therapeutic drugs

This review focuses on basic aspects and recent studies of hair analysis for abused and therapeutic drugs and is discussed with 164 references. Firstly, biology of hair and sampling of hair specimens have been commented for the sake of correct interpretation of the results from hair analysis. Then the usual washing methods of hair samples and the extraction methods for drugs in hair have been shown and commented on. Analytical methods for each drug have been discussed by the grouping of three analytical methods, namely immunoassay, HPLC-CE and GC-MS. The outcomes of hair analysis studies have been reviewed by dividing into six groups; morphine and related, cocaine and related, amphetamines, cannabinoids, the other abused drugs and therapeutic drugs. In addition, reports on stability of drugs in the living hair and studies on drug incorporation into hair and dose-hair concentration relationships have been reviewed. Applications of hair analysis to the estimation of drug history, discrimination between OTC drug use and illegal drug use, drug testing for acute poisoning, gestational drug exposure and drug compliance have also been reviewed. Finally, the promising prospects of hair analysis have been described.

Testing for drugs in hair. Critical review of chromatographic procedures since 1992

Up to now, more than 50 pharmaceuticals or drugs of abuse have been reported to be detectable in hair after oral or parenteral administration. The present paper reviews the literature devoted to drug testing in hair that has been published since 1992. Procedures for the detection of opiates, cocaine, amphetamines and cannabis in hair are described in detail. In particular, the papers on benzodiazepines show an increasing number of procedures using negative chemical ionisation with GC-MS and diode array detection with HPLC in hair analysis. For the most important benzodiazepines, diazepam and flunitrazepam, reliable methods now exist. On the other hand, the problem of the detecting tetrahydrocannabinol metabolites using different techniques is not yet solved. Some progress is observed in the detection of low dose drugs, like fentanyl and its derivatives or LSD. For most of the analyses using chromatographic techniques, the main data on sample preparation and analytical determinations are listed. Some new findings, based on the experience of the authors, are also added.

Hair analysis, a novel tool in forensic and biomedical sciences: new chromatographic and electrophoretic/electrokinetic analytical strategies

Hair analysis for abused drugs is recognized as a powerful tool to investigate exposure of subjects to these substances. In fact, drugs permeate the hair matrix at the root level and above. Evidence of their presence remains incorporated into the hair stalk for the entire life of this structure. Most abusive drugs (e.g. opiates, cocaine, amphetamines, cannabinoids etc.) and several therapeutic drugs (e.g. antibiotics, theophylline, beta 2-agonists, etc.) have been demonstrated to be detectable in the hair of chronic users. Hence, hair analysis has been proposed to investigate drug abuses for epidemiological, clinical, administrative and forensic purposes, such as in questions of drug-related fatalities and revocation of driving licences, alleged drug addiction or drug abstinence in criminal or civil cases and for the follow-up of detoxication treatments. However, analytical and interpretative problems still remain and these limit the acceptance of this methodology, especially when the results from hair analysis represent a single piece of evidence and can not be supported by concurrent data. The present paper presents an updated review (with 102 references) of the modern techniques for hair analysis, including screening methods (e.g. immunoassays) and more sophisticated methodologies adopted for results confirmation and/or for research purposes, with special emphasis on gas chromatography-mass spectrometry, liquid chromatography and capillary electrophoresis.

Immunoassay of digoxin in hair

Digoxin analysis in blood is an essential tool for therapeutic drug monitoring in cardiology because compliance with the treatment is a critical issue for the patient. Unfortunately, in postmortem cases blood digoxin concentration is of poor quality because there is a possible drug redistribution in the corpse and because of digoxin-like factors present in some people's blood. On the other hand, no biological fluid can be obtained at the autopsy. The aim of the present study was to evaluate the ability of an immunological method to determine digoxin in hair, in order to confirm that hair analysis can provide information on digoxin use before death. We studied 35 elderly patients who had been taking digoxin (60-250 micrograms/day) for 1-5 years. Two decontamination procedures were tested: washing by dichloromethane or by water and methanol. Three extraction procedures were compared: crushing in a ball mill and chloroform/acetone: crushing and methanol; enzymatic digestion. Immunoassays were performed by a microparticulate enzyme immunoassay. Serum digoxin levels were also assayed when sampling hair. The best results were obtained after decontamination with water and methanol followed by enzymatic digestion. Hair digoxin concentrations range from 3.6 to 11.4 pg/mg. Those very low concentrations are probably due to low and narrow range serum digoxin levels (0.3-1.4 ng/ml). No correlation was found between hair and blood digoxin. A forensic case is presented with 5 pg/mg digoxin in hair.

Hair opiates during pain treatment

Opiates are commonly used for pain treatment, especially for sharp pain like carcinoma pain. Two opiates are generally prescribed in our hospital: morphine and codeine in association with paracetamol. Most of the patients were given oral forms. Incorporation of morphine and codeine in hair of these patients was studied. Opiates testing in hair is performed by gas chromatography-mass spectrometry (GC-MS), using acid hydrolysis in presence of deuterated standards, a three-step liquid extraction and derivatization with BSTFA + TMCS. Results of codeine and morphine content in hair during pain treatment showed no correlation group between dose and concentration of the drug in hair. However, codeine values in hair during pain treatment compared to codeine in the hair of codeine abusers was significantly different (P < 0.0001).

Determination of drugs in hair using GC/MS/MS

An important task for the forensic toxicologist and expert witness is the detection of the noxa in biological matrices. Because of this, the identification and quantification of residues of illegal drugs in human hair is still of growing interest. Utilizing the advantages of GC/MS/MS testing human hair is performed for most common drugs of abuse like heroin and other opioides, cocaine, cannabis and amphetamine derivatives. Analyzing hair specimens for substances that present a toxicological risk is another challenge. Several quality control parameters must be observed to avoid false positive or false negative results and to gain additional information. Blank sample, blank hair as well as the combined wash extracts are tested for the presence of the relevant compounds within every series. Careful evaluation of the findings can provide an approximate measure of the intensity of drug use in the majority of cases.

Analysis of fentanyl and sufentanil in hair by GC/MS/MS

Fentanyl and sufentanil are potent narcotic analgesics used only in hospitals as anaesthetic agents. The dependence potential of fentanyl is known. As they are given in doses at the microgram level and their elimination half-life is in the order of a few hours, detection in body fluids is possible only for a short time after administration. Radioimmunological methods are the only ones capable of detecting fentanyl in hair, as normal GC/MS methods for hair analysis are not sensitive enough to detect the drugs after doses in the order of micrograms. We therefore chose GC/MS/MS to analyse fentanyl and sufentanil in two cases where the drugs were given under controlled conditions over several days. The concentration was in the order of less than 100 pg/mg hair.

[A new tool for biological study: hair analysis. Value in medical practice]

Testing hair has been used since two hundred years for arsenic determination. Fifteen years ago, Baumgartner published the first report on the detection of morphine in the hair of heroin abusers by radio-immuno-assay. Today the development of new methods like gas chromatography/mass spectrometry has permitted numerous applications based on the analysis of organic substances trapped in hair. Personal observations and a review of the literature are presented in this paper to document the following clinical applications: hair as a screening procedure of psychiatric patients; hair and epileptic management; hair as a tool for monitoring neuroleptics; hair as evidence of gestational drug exposure; hair nicotine as a marker of passive exposure to tobacco; detection and clinical survey of heroin addict; evaluation of pharmaceutical exposure; hair analysis as a tool of clinical diagnosis; hair analysis for compliance monitoring.

Drug testing in addicts: a comparison between urine, sweat, and hair

The standard in drug testing is the immunoassay screen, followed by a gas chromatography/mass spectrometry confirmation conducted on a urine sample. Recently sweat and hair analyses were proposed for identifying drug abusers. Specimens can be collected under close supervision without embarrassment and are not subject to evasive maneuvers. In contrast with urine, hair analysis has a wide window of detection, ranging from months to years, and provides information concerning the severity and pattern of an individual's drug abuse. Testing individuals for illicit drugs with sweat patches worn continually would provide effective coverage for a week. Studies conducted in a detoxification center have shown that hair analysis is more sensitive for detecting illicit drug use than is urine screening. My experience in drug testing is discussed in the light of the existing literature.

Sensitive and selective assay for fentanyl using gas chromatography with mass selective detection

A modified gas chromatographic assay, using mass-selective detection, has been developed for the quantitation of fentanyl in swine serum. Fentanyl and sufentanil, the internal standard, were extracted using a single-step liquid-liquid extraction with dichloromethane. Sensitivity and selectivity were improved by using electron-impact ionization (EI) in the selected-ion monitoring (SIM) mode, where fentanyl and sufentanil were monitored using the fragment ions at m/z 245 and 289, respectively. The limit of quantitation (LOQ) is 0.05 ng/ml, using 1 ml of sample, with a C.V. of 10.8% and a signal-to-noise ratio of 29. Standard curves were linear (r2 = 0.999) over the working range of 0.05-1/5 ng/ml, using 1/y2 as a weighting factor. Recoveries averaged 69.8 +/- 4.7%, 91.0 +/- 13.0% and 90.9 +/- 10.3% at serum concentrations of 1.5, 0.5 and 0.1 ng/ml, respectively. Intra- and inter-day variances, were < 12% at 0.1 ng/ml, and < 10% at concentrations of 0.5, 1 and 1.5 ng/ml. Bias was 6.2% at the LOQ and < or = 12.8% at every other standard curve concentration. Applicability of the assay is demonstrated for the pharmacokinetic study of transdermally administered fentanyl in a postoperative swine.

Hair analysis: a worthless tool for therapeutic compliance monitoring

Hair analysis has been presented by some authors as a possible tool of investigation for estimating patients' compliance to long-term therapies. This paper summarises the different publications that have been devoted to this topic and highlights the available statistically data presented to support this proposition. Qualitative results of such determinations may be of some interest but due to the enormous interindividual variations of quantitative data, the idea of using hair analysis to ascertain whether a patient has taken his treatment exactly as prescribed, clearly appears to be inapplicable.