The effects of collection methods on oral fluid codeine concentrations

Clinical Value of Emerging Bioanalytical Methods for Drug Measurements: A Scoping Review of Their Applicability for Medication Adherence and Therapeutic Drug Monitoring

INTRODUCTION

Direct quantification of drug concentrations allows for medication adherence monitoring (MAM) and therapeutic drug monitoring (TDM). Multiple less invasive methods have been developed in recent years: dried blood spots (DBS), saliva, and hair analyses.

AIM

To provide an overview of emerging drug quantification methods for MAM and TDM, focusing on the clinical validation of methods in patients prescribed chronic drug therapies.

METHODS

A scoping review was performed using a systematic search in three electronic databases covering the period 2000-2020. Screening and inclusion were performed by two independent reviewers in Rayyan. Data from the articles were aggregated in a REDCap database. The main outcome was clinical validity of methods based on study sample size, means of cross-validation, and method description. Outcomes were reported by matrix, therapeutic area and application (MAM and/or TDM).

RESULTS

A total of 4590 studies were identified and 175 articles were finally included; 57 on DBS, 66 on saliva and 55 on hair analyses. Most reports were in the fields of neurological diseases (37%), infectious diseases (31%), and transplantation (14%). An overview of clinical validation was generated of all measured drugs. A total of 62 drugs assays were applied for MAM and 131 for TDM.

CONCLUSION

MAM and TDM are increasingly possible without traditional invasive blood sampling: the strengths and limitations of DBS, saliva, and hair differ, but all have potential for valid and more convenient drug monitoring. To strengthen the quality and comparability of future evidence, standardisation of the clinical validation of the methods is recommended.

Adherence to Antihypertensive Drugs Assessed by Hyphenated High-Resolution Mass Spectrometry Analysis of Oral Fluids

Background

It is currently unknown if antihypertensive drugs can be monitored in oral fluid (OF) using liquid chromatography coupled to high‐resolution mass spectrometry.

Methods and Results

We assessed adherence using liquid chromatography coupled to high‐resolution mass spectrometry in OF, plasma, and urine of 56 consecutive patients with hypertension referred to a tertiary hypertension unit. Of these patients, 59% were completely adherent (all drugs detectable in urine), whereas 29% and 13% were partially adherent (1 drug not detectable in urine) or nonadherent (>1 drug not detectable in urine), respectively. Adherent patients were on fewer antihypertensive drugs (P=0.001), had fewer daily drug doses (P=0.012), and had lower 24‐hour ambulatory systolic (P=0.012) and diastolic (P=0.009) blood pressures than nonadherent or partially adherent patients. Most drugs were detected in urine compared with plasma and OF (181 versus 119 versus 88; P=0.001). Compared with urine and plasma, detection rates of angiotensin‐converting enzyme inhibitors, angiotensin II receptor blockers, and diuretics were lower in OF. There was no difference in the frequency of detecting β blockers (P=1.0) and calcium channel blockers (P=0.063) when comparing OF with urine. There was no difference in the number of calcium channel blockers (P=0.727), β blockers (P=1.000), thiazide diuretics (P=0.125), and α‐2 agonists (P=0.125) identified between OF and plasma.

Conclusions

This study shows the feasibility of drug adherence testing for several antihypertensive drugs, especially those without acidic components, in OF, with a similar recovery compared with plasma. Therefore, drug adherence testing in OF should be further explored as a noninvasive approach, which can easily be performed in an “out‐of‐office” setting.

An Experimental Pharmacokinetics Study of Diazepam and Its Metabolites in Oral Fluid of Chinese Population

Diazepam abuse is widespread all over the word, leading to an increasing number of forensic cases such as suicide, drug-driving and robbery, but relevant studies are limited regarding the extraction of diazepam and its metabolites in oral fluid. This study aimed to investigate the pharmacokinetics of diazepam and its metabolites in oral fluid after a single oral dose in healthy volunteers. There was a total of 28 volunteers, and each ingested 5 mg diazepam orally, then ~2 mL oral fluid were collected from each participant at post-consumption time-points of prior (zero), 1, 2, 4, 8, 12, 24 h and 2, 3, 6, 12 and 15 days, respectively. All samples were extracted with solid-phase extraction and analyzed with high-performance liquid chromatography-tandem mass spectrometry method, and diazepam and nordazepam were detected in the oral fluid of volunteers. Pharmacokinetics of diazepam in oral fluid conformed to a two-compartment model, and k01_HL, k12_HL, k10_HL were 0.7 ± 1.1, 31.4 ± 68.5, 12.1 ± 11.6 h, respectively, nordazepam conformed to an one-compartment model, and k01_HL, k10_HL were 41.5 ± 44.8, 282.3 ± 365.5 h, respectively. Both diazepam and nordazepam could be detected continuously for 15 days, although there were individual differences, and the results regarding diazepam detecting in oral fluid will be of much help in forensic science and drug screening filed.

Oral Fluid to Blood Concentration Ratios of Different Psychoactive Drugs in Samples from Suspected Drugged Drivers

BACKGROUND

The ratio between the concentrations of drugs in the oral fluid and blood (OF/B ratio) reflects the transfer of drugs from blood to oral fluid, which is influenced by several factors such as oral fluid contamination. OF/B drug concentration ratios for psychoactive drugs, including interindividual variation, were investigated in this study. For a portion of the material, oral fluid concentrations in both sides of the mouth were compared.

METHODS

Samples of whole blood and oral fluid collected using the Intercept device were obtained from 489 suspected drugged drivers. Concentrations of amphetamine, methamphetamine, THC, diazepam, N-desmethyldiazepam, clonazepam, alprazolam, oxazepam, nitrazepam, morphine, buprenorphine, and methadone were determined in blood and oral fluid samples using liquid chromatography-tandem mass spectrometry.

RESULTS

Median OF/B ratios were 18.6 for amphetamine, 13.8 for methamphetamine, 3.8 for morphine, 24.8 for buprenorphine, 3.7 for methadone, 0.026 for diazepam, 0.031 for N-desmethyldiazepam, 0.28 for alprazolam, 0.16 for clonazepam, 0.12 for oxazepam, 0.099 for nitrazepam, and 4.3 for THC. Large interindividual variations in OF/B ratios were observed. The median difference in concentrations in oral fluid from both sides of the mouth was less than 20% for all drugs, except THC and buprenorphine, which had median differences of 32%-34%.

CONCLUSIONS

High OF/B ratios were found for amphetamines and opioids, reflecting a high degree of drug transfer from blood to oral fluid and a longer detection window in oral fluid than in blood. For benzodiazepines, low OF/B ratios were found. Results of the concentration measurements in oral fluid from both sides of the mouth could indicate that some remnants of THC and buprenorphine were present in the oral cavity. The large variations among individuals and between the 2 sides of the mouth suggest that drug concentrations in oral fluid do not accurately reflect drug concentrations in the blood.

Oral Fluid Drug Testing: Analytical Approaches, Issues and Interpretation of Results

With advances in analytical technology and new research informing result interpretation, oral fluid (OF) testing has gained acceptance over the past decades as an alternative biological matrix for detecting drugs in forensic and clinical settings. OF testing offers simple, rapid, non-invasive, observed specimen collection. This article offers a review of the scientific literature covering analytical methods and interpretation published over the past two decades for amphetamines, cannabis, cocaine, opioids, and benzodiazepines. Several analytical methods have been published for individual drug classes and, increasingly, for multiple drug classes. The method of OF collection can have a significant impact on the resultant drug concentration. Drug concentrations for amphetamines, cannabis, cocaine, opioids, and benzodiazepines are reviewed in the context of the dosing condition and the collection method. Time of last detection is evaluated against several agencies' cutoffs, including the proposed Substance Abuse and Mental Health Services Administration, European Workplace Drug Testing Society and Driving Under the Influence of Drugs, Alcohol and Medicines cutoffs. A significant correlation was frequently observed between matrices (i.e., between OF and plasma or blood concentrations); however, high intra-subject and inter-subject variability precludes prediction of blood concentrations from OF concentrations. This article will assist individuals in understanding the relative merits and limitations of various methods of OF collection, analysis and interpretation.

Conducting Rapid Street Assessment of Drug Users in New York City Using Oral Fluid and Brief Interviews: A Feasibility Study

This study piloted the feasibility of rapidly collecting both self-reports of drug use and saliva specimens for drug toxicology in field settings. The use of oral fluid collection devices to supplement self-reports is unproven in street settings and may pose challenges for field research. Sixty adults who identified as recent illicit drug users were recruited in public settings in New York City and were asked to complete a brief drug screening inventory and provided saliva specimens. Descriptive findings are detailed along with critical best research practices and limitations that provide important directions for researchers looking to employ both toxicology and self-report in rapid field recruitment designs.

Detection of 4 benzodiazepines in oral fluid as biomarker for presence in blood

BACKGROUND

Analysis of samples of oral fluid (mixed saliva) is increasingly being used to detect recent drug use. The aim of this investigation was to assess the suitability of testing oral fluid as a biomarker for the presence of 4 benzodiazepines in blood and its possible application in clinical settings and in research on drug use.

METHODS

Paired samples of oral fluid and blood from 4080 individuals in 4 European countries were collected and analyzed for benzodiazepines using gas or liquid chromatography with mass spectroscopic detection.

RESULTS

Concentration data for the 4 most commonly detected benzodiazepines were studied: alprazolam, clonazepam, diazepam, and nordiazepam. Large variations in oral fluid to blood concentration ratios were observed for the studied benzodiazepines. The interquartile ranges for the oral fluid to blood concentrations ratios corresponded to 88%-197% of the median values. Selecting cutoff concentrations in oral fluid that gave the best accuracy in identifying individuals with benzodiazepine concentrations in blood above chosen thresholds produced accuracies of 74%-85% and the fraction of false negatives was 9%-23%.

CONCLUSIONS

The concentration of the 4 studied benzodiazepines in oral fluid can neither be used to accurately estimate the concentrations in blood nor to correctly identify patients with blood drug concentrations below or above recommended therapeutic levels. When using analytical methods with limits of quantitation corresponding to concentrations less than 0.5 ng/mL in undiluted oral fluid, it may be used to confirm a recent intake of benzodiazepines. However, it is likely that some false negatives may occur.

Random and systematic errors in case-control studies calculating the injury risk of driving under the influence of psychoactive substances

Between 2006 and 2010, six population based case-control studies were conducted as part of the European research-project DRUID (DRiving Under the Influence of Drugs, alcohol and medicines). The aim of these case-control studies was to calculate odds ratios indicating the relative risk of serious injury in car crashes. The calculated odds ratios in these studies showed large variations, despite the use of uniform guidelines for the study designs. The main objective of the present article is to provide insight into the presence of random and systematic errors in the six DRUID case-control studies. Relevant information was gathered from the DRUID-reports for eleven indicators for errors. The results showed that differences between the odds ratios in the DRUID case-control studies may indeed be (partially) explained by random and systematic errors. Selection bias and errors due to small sample sizes and cell counts were the most frequently observed errors in the six DRUID case-control studies. Therefore, it is recommended that epidemiological studies that assess the risk of psychoactive substances in traffic pay specific attention to avoid these potential sources of random and systematic errors. The list of indicators that was identified in this study is useful both as guidance for systematic reviews and meta-analyses and for future epidemiological studies in the field of driving under the influence to minimize sources of errors already at the start of the study.

Screening for drugs of abuse: which matrix, oral fluid or urine?

Urine is recognized as the prime matrix for drug test screening with well-established methods and testing protocols. Its major limitation is with regard to the inconvenience of sample collection and lack of integrity due to adulteration, dilution, drug spiking or sample exchange. The question is whether oral fluid, with its apparent better sample integrity, can replace urine for drug screening. This review examines the sample integrity problems and the advantages and limitations of oral fluid and urine in drug screening programmes. The variety of sample collection devices for oral fluid is shown to be a problem with recovery and detection for some drugs. This is examined in relation to the pharmacokinetics of drug metabolism and excretion in this matrix. Buccal contamination with drugs in oral fluid may also cause problems with interpretation. The clinical advantages of oral fluid analysis compared with urine testing are highlighted. Parent drugs are often found in oral fluid where only their metabolites may be found in urine, for example the benzodiazepines. 6-Monoacetylmorphine, an indicative marker of heroin, has a high prevalence in oral fluid from users of this drug but its detection in urine is limited due to its short half-life. Advances in analytical techniques, particularly chromatography linked to tandem mass spectrometry, are helping to promote oral fluid analysis. However, the lack of concordance studies examining both urine and oral fluid drug levels and kinetics in the clinical setting is of some concern.

Saliva as an analytical matrix: state of the art and application for biomonitoring

Analytical tests to measure chemicals in saliva can be employed for numerous analytes, endogenous compounds or xenobiotics. The objective was to determine which chemicals can be analysed with this matrix, which analytical methods are applicable, and what application is possible for biomonitoring. We reviewed the literature using three databases, MEDLINE, PubMed and Scopus, collecting articles on different kinds of analysis in saliva. Studies were principally about molecules of clinical interest, xenobiotics, especially drugs of abuse, and chemicals used at workplaces; some substances show no relevant correlation with exposure data while others seems to be of particular interest for systematic use for biomonitoring. Currently, saliva is used far less than other biological fluids but its use for biomonitoring of exposure to chemicals might open up new areas for research and would certainly simplify the collection of biological samples.

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.

Biological testing for drugs of abuse

Testing for drugs of abuse has become commonplace and is used for a variety of indications. Commonly employed testing methods include immunoassay and chromatography. Testing methods vary in their sensitivity, specificity, time, and cost. While urine remains the most common body fluid used for testing of drugs of abuse, over the last several decades the use of alternative matrices such as blood, sweat, oral fluids, and hair has increased dramatically. Each biological matrix offers advantages and disadvantages for drug testing, and the most appropriate matrix frequently depends on the indications for the drug test. Drugs of abuse that are most commonly tested include alcohol, amphetamines, cannabinoids, cocaine, opiates, and phencyclidine. Testing may involve detection of the parent compound or metabolites and sensitivity, specificity, and reliability of drug testing may vary depending on the drug being tested. Toxicologists have a responsibility to understand the strengths and limitations of testing techniques and matrices to be able to critically evaluate the results of a drug test.

Oral fluid testing for drugs of abuse

BACKGROUND

Oral fluid (OF) is an exciting alternative matrix for monitoring drugs of abuse in workplace, clinical toxicology, criminal justice, and driving under the influence of drugs (DUID) programs. During the last 5 years, scientific and technological advances in OF collection, point-of-collection testing devices, and screening and confirmation methods were achieved. Guidelines were proposed for workplace OF testing by the Substance Abuse and Mental Health Services Administration, DUID testing by the European Union's Driving under the Influence of Drugs, Alcohol and Medicines (DRUID) program, and standardization of DUID research. Although OF testing is now commonplace in many monitoring programs, the greatest current limitation is the scarcity of controlled drug administration studies available to guide interpretation.

CONTENT

This review outlines OF testing advantages and limitations, and the progress in OF that has occurred during the last 5 years in collection, screening, confirmation, and interpretation of cannabinoids, opioids, amphetamines, cocaine, and benzodiazepines. We examine controlled drug administration studies, immunoassay and chromatographic methods, collection devices, point-of-collection testing device performance, and recent applications of OF testing.

SUMMARY

Substance Abuse and Mental Health Services Administration approval of OF testing was delayed because questions about drug OF disposition were not yet resolved, and collection device performance and testing assays required improvement. Here, we document the many advances achieved in the use of OF. Additional research is needed to identify new biomarkers, determine drug detection windows, characterize OF adulteration techniques, and evaluate analyte stability. Nevertheless, there is no doubt that OF offers multiple advantages as an alternative matrix for drug monitoring and has an important role in DUID, treatment, workplace, and criminal justice programs.

Current technologies and considerations for drug bioanalysis in oral fluid

Drug oral fluid analysis was first used almost 30 years ago for the purpose of therapeutic drug monitoring. Since then, oral fluid bioanalysis has become more popular, mainly in the fields of pharmacokinetics, workplace drug testing, criminal justice, driving under the influence testing and therapeutic drug monitoring. In fact, oral fluid can provide a readily available and noninvasive medium, without any privacy loss by the examinee, which occurs, for instance, during the collection of urine samples. It is believed that drug concentrations in oral fluid may parallel those measured in blood. This feature makes oral fluid an alternative analytical specimen to blood, which assumes particular importance in roadside testing, the most published application of this sample. Great improvements in the development of accurate and reliable methods for sample collection, in situ detection devices (on-site drug detection kits), and highly sensitive and specific analytical methods for oral fluid testing of drugs have been observed in the last few years. However, without mass spectrometry-based analytical methods, such as liquid chromatography coupled to mass spectrometry (LC–MS) or tandem mass spectrometry (LC–MS/MS), the desired sensitivity would not be met, due to the low amounts of sample usually available for analysis. This review will discuss a series of published papers on the applicability of oral fluid in the field of analytical, clinical and forensic toxicology, with a special focus on its advantages and drawbacks over the normally used biological specimens and the main technological advances over the last decade, which have made oral fluid analysis of drugs possible.

Laboratory evaluation and field application of roadside oral fluid collectors and drug testing devices

This study was a part of a collaborative U.S./E.U. international research effort (Roadside Testing Assessment, ROSITA II) to assess illegal drug use among motor vehicle operators suspected of driving while under the influence of drugs and to evaluate the effectiveness of point-of-collection oral fluid drug detection technologies. A goal of the study was to assess commercial oral fluid drug testing devices for potential use in law enforcement. Ten devices were evaluated in the laboratory for their ability to meet manufacturers' claimed (and proposed) cutoff concentrations for the detection of amphetamine(s), cocaine/metabolite, opiates, cannabinoids, and benzodiazepines (2 devices). The field study portion of the research was conducted in major cities in the United States and Western Europe by teams of scientists working in collaboration with the local police. In Salt Lake City, Utah, the Drugwipe, Securetec, Ottobrunn, Germany (Securetec) oral fluids drug testing device was also evaluated in the field by testing suspected drug-impaired drivers. During the initial phase of the field study, 40 subjects were recruited. Drugwipe results were compared with laboratory-based immunoassay and mass spectrometry results and demonstrated that calculated sensitivities were between 75% and 100% depending on drug class. Specificities varied from 36% for cannabinoids to over 95% for opiates. During the second phase of the field study, 267 subjects were recruited. The Drugwipe sensitivities were 36.4%, 35.9%, 42.9%, and 7.7%, respectively, for amphetamine(s), cocaine, opiates, and cannabinoids. The Drugwipe specificities were 99.2%, 97.4%, 99.6%, and 99.6%, respectively, for amphetamine(s), cocaine, opiates, and cannabinoids. Drugwipe failed to meet the study criteria for acceptable device performance, required performance sensitivities, and specificities 90% or greater.

Evaluation of a novel standardized system for collection and quantification of oral fluid

BACKGROUND

Standardization in collection and testing of oral fluid is lacking.

METHODS

A novel standardized collection and quantification system for oral fluid testing was evaluated. Sample collection volumes were determined. For determination of the saliva content in oral fluid samples, tartrazine, which is an integral part of the saliva extraction solution serving as an internal standard, was used. Results were compared with those obtained by employing glucose as a 'supplemental internal standard' for determination. Analytical performance of the new system for collection and quantification of oral fluid was evaluated. Calcium and magnesium analyte concentrations in oral fluid samples were measured with a routine laboratory method and compared to a reference method.

RESULTS

Volumes of oral fluid samples collected ranged from 4.9 to 10.5 mL. The mean saliva content in oral fluid samples was found to be 65.5 percent by volume (vol.-%) when determined through the tartrazine concentration and 65.0 vol.-% when determined through the glucose concentration. Evaluation of analytical performance revealed interassay imprecision coefficients of variation (CVs) ranging from 1.5% to 3.2% and intraassay imprecision CVs from 1.1% to 2.5%. When linearity was tested, a quasi-linear curve was observed (R2=0.99). Comparison of two different methods for determination of calcium and magnesium concentrations showed correlations of R2=0.96 for calcium and R2=0.97 for magnesium.

CONCLUSIONS

The new system for collection and quantification of oral fluid helps to improve standardization of pre-analytics in oral fluid testing and to provide reliable and accurate quantification of analytes in oral fluid samples.

A simple and reliable procedure for the determination of psychoactive drugs in oral fluid by gas chromatography–mass spectrometry

A simple and reliable gas chromatography-mass spectrometry method for identifying and quantifying psychoactive drugs in oral fluid is described. Substances under investigation were: psychostimulant drugs (amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxiamphetamine, 3,4-methylenedioxy-N-ethylamphetamine, phentermine), cocaine and metabolites (benzoylecgonine, cocaethylene, and ecgonine methyl esther), cannabinoids (delta-9-tetrahydrocannabinol, 11-nor-9-carboxy-delta-9-tetrahydrocannabinol, 11-hydroxy-delta-9-tetrahydrocannabinol, cannabinol and cannabidiol), opiates (6-monoacetylmorphine, morphine and codeine), hypnotics (flurazepam, flunitrazepam, dipotassium chlorazepate, alprazolam, diazepam and oxazepam), antidepressant drugs (amitryptiline, paroxetine and sertraline), antipsychotic drugs (haloperidol, chlorpromazine and fluphenazine) chlormethiazole, loratidine, hydroxyzine, diphenhydramine, valproic acid and gabapentin. After the addition of deuterated analogues of morphine, 3,4-methylenedioxymethamphetamine, (+/-)-11-nor-9-carboxy-delta-9-tetrahydrocannabinol and clonazepam as internal standards, all the compounds were simultaneously extracted from oral fluid by solid-phase extraction procedure. Acid compounds were eluted with acetone while basic and neutral compounds with dichloromethane:isopropanol:ammonium (80:20:2, v/v/v). Chromatography was performed on a methylsilicone capillary column and analytes, derivatized with N-Methyl-N-(trimethylsilyl)trifluoroacetamide, were determined in the selected-ion-monitoring (SIM) mode. Mean recovery ranged between 44.5 and 97.7 % and quantification limit between 0.9 and 44.2 ng/ml oral fluid for the different analytes. The developed analytical methodology was applied to investigate the presence of psychoactive drugs in oral fluid from injured individuals attending the emergency room (MACIUS project).

Oral fluid as an alternative matrix to monitor opiate and cocaine use in substance-abuse treatment patients

Interest in oral fluid as an alternative matrix for monitoring drug use is due to its ease-of-collection and non-invasiveness; however, limited data are available on the disposition of drugs into oral fluid. The objective of this research was to provide data on the presence and concentrations of heroin, cocaine and multiple metabolites in oral fluid after illicit opioid and cocaine use. Thrice weekly oral fluid specimens (N=403) from 16 pregnant opiate-dependent women were obtained with the Salivette oral fluid collection device. Evidence of heroin (N=62) and cocaine (N=130) use was detected in oral fluid by LC-APCI-MS/MS. 6-Acetylmorphine (6-AM), heroin and morphine were the major opiates detected, with median concentrations of 5.2, 2.3, and 7.5 microg/L, respectively. Cocaine and benzoylecgonine (BE) had median concentrations of 6.4 and 3.4 microg/L. Application of the Substance Abuse Mental Health Services Administration (SAMHSA) recommended cutoffs for morphine and codeine (40 microg/L), 6-AM (4 microg/L) and cocaine and BE (8 microg/L), yielded 28 opiate- and 50 cocaine-positive specimens. Oral fluid is a promising alternative matrix to monitor opiate and cocaine use in drug testing programs. These data guide interpretation of oral fluid test results and evaluate currently proposed SAMHSA oral fluid testing cutoffs.

Use of gas chromatography/mass spectrometry with positive chemical ionization for the determination of opiates in human oral fluid

An analytical method for the simultaneous determination of codeine, morphine and 6-acetylmorphine (6AM) in human oral fluid was developed. The method involves liquid-liquid extraction in Toxitubes A, derivatization with 99:1 (v/v) N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA)/trimethylchlorosilane (TMCS), and gas chromatography/mass spectrometry with positive chemical ionization (GC/PCI-MS) determination. The detector response was linear over the concentration range 30-500 ng/mL with coefficients of correlation higher than 0.99. The precision was acceptable with coefficients of variation less than 7.5%. The limits of detection achieved were 0.7 ng/mL for codeine, 2.0 ng/mL for morphine, and 0.6 ng/mL for 6AM. The method proposed was applied to 80 oral fluid samples from opiates users, 98% of which were positive for the three analytes. Human oral fluid is a suitable biological fluid for the determination of opiates by GC/PCI-MS.

Oral fluid collection: the neglected variable in oral fluid testing

The potential to use oral fluid as a drug-testing specimen has been the subject of considerable scientific interest. The ease with which specimens can be collected and the potential for oral fluid (OF) drug concentrations to reflect blood-drug concentrations make it a potentially valuable specimen in clinical as well as forensic settings. However, the possible effects of the OF collection process on drug detection and quantification has often been over looked. Several studies have documented that drug-contamination of the oral cavity may skew oral fluid/blood drug ratios and confound interpretation when drugs are smoked, insufflated or ingested orally. OF pH is predicted to have an effect on the concentration of drugs in OF. However, in a controlled clinical study, the effect of pH was less than that of collection technique. Mean codeine OF concentrations in specimens collected a non-stimulating control method were 3.6 times higher than those in OF collected after acidic stimulation. Mean codeine concentrations were 50% lower than control using mechanical stimulation and 77% of control using commercial collection devices. Several factors should be considered if a commercial OF collection device is used. In vitro collection experiments demonstrated that the mean collection volume varied between devices from 0.82 to 1.86 mL. The percentage of the collected volume that could be recovered from the device varied from 18% to 83%. In vitro experiments demonstrated considerable variation in the recovery of amphetamines (16-59%), opiates (33-50%), cocaine and benzoylecgonine (61-97%), carboxy-THC (0-53%) and PCP (9-56%). Less variation in collection volume, volume recovered and drug recovery was observed intra-device. The THC stability was evaluated in a common commercial collection protocol. Samples in the collection buffer were relatively stable for 6 weeks when stored frozen. However, stability was marginal under refrigerated conditions and poor at room temperature. Very little has been published on the efficacy of using IgG concentration, or any other endogenous marker, as a measure of OF specimen validity. Preliminary rinsing experiments with moderate (50 mL and 2 x 50 mL) volumes of water did not reduce the OF IgG concentration below proposed specimen validity criteria. In summary, obvious and more subtle variables in the OF collection may have pronounced effects on OF-drug concentrations. This has rarely been acknowledged in the literature, but should to be considered in OF drug testing, interpretation of OF-drug results and future research studies.

Oral fluid testing for driving under the influence of drugs: history, recent progress and remaining challenges

In recent years the demand for drug testing in oral fluid in cases of driving under the influence has been increasing. The main advantages of saliva/oral fluid are the possibility for non-medical personnel to collect it without embarrassment and a better correlation between presence of drugs in oral fluid and impairment. Several surveys have been performed since the 1980s using saliva, and researchers encountered problems related to insufficient sample volume and insufficient sensitivity of the analytical methods. Steady progress has been shown in sample collection, knowledge of toxicokinetics in oral fluid, reliability of on-site and laboratory-based immunoassays and confirmation methods. In a few countries, legislation was passed that allows the use of saliva as a matrix for screening or confirmation. Despite this progress, some more work needs to be done, principally in the areas of the sensitivity and reliability of on-site screening devices, particularly for cannabis and benzodiazepines, knowledge about passive contamination and more generalised proficiency testing before oral fluid testing for DUID will have the reliability needed to be used forensically.

Analysis of Δ9-tetrahydrocannabinol in oral fluid samples using solid-phase extraction and high-performance liquid chromatography–electrospray ionization mass spectrometry

An analytical method using solid-phase extraction (SPE) and high-performance liquid chromatography-mass spectrometry (LC-MS) has been developed and validated for the confirmation of Delta(9)-tetrahydrocannabinol (THC) in oral fluid samples. Oral fluid was extracted using Bond Elut LRC-Certify solid-phase extraction columns (10 cm(3), 300 mg) and elution performed with n-hexane/ethyl acetate. Quantitation made use of the selected ion-recording mode (SIR) using the most abundant characteristic ion [THC+H(+)], m/z 315.31 and the fragment ion, m/z 193.13 for confirmation, and m/z 318.00 for the protonated internal standard, [d(3)-THC+H(+)]. The method proved to be precise for THC, in terms of both intra-day and inter-day analyses, with coefficients of variation less than 10%, and the calculated extraction efficiencies for THC ranged from 76 to 83%. Calibration standards spiked with THC between 2 and 100 ng/mL showed a linear relationship (r(2)=0.999). The method presented was applied to the oral fluid samples taken from the volunteers during the largest music event in Portugal, named Rock in Rio-Lisboa. Oral fluid was collected from 40 persons by expectoration and with Salivette. In 55% of the samples obtained by expectorating, THC was detected with concentration ranges from 1033 to 6552 ng/mL and in 45% of cases THC was detected at concentrations between 51 and 937 ng/mL. However, using Salivette collection, 26 of the 40 cases had an undetectable THC.

Review: Pharmacokinetics of illicit drugs in oral fluid

This article reviews studies that have measured drug concentrations in oral fluid following controlled dosing regimens. A total of 23 studies have been identified over the last 15 years. These show that the amphetamines including designer amphetamines, cocaine, cannabis and cocaine are quickly found in oral fluid following dosing and usually have similar time-courses to that in plasma. Following common doses peak oral fluid concentrations exceed 0.1 microg/mL and often even 1 microg/mL. The drug concentration will depend on whether a dilution step occurs with buffer as part of the sampling procedure. The uses of collectors that stimulate oral fluid usually reduce the drug concentration compared to a non-stimulated manner. This reduction will not disadvantage the recipient since it will potentially reduce the detectability of drug in oral fluid compared to non-stimulated collections. Only one recent study has been reported for a benzodiazepine. This showed nanogram per milliliter concentrations for flunitrazepam. More studies are required for benzodiazepines and indeed for other drugs, particularly in multiple drug situations and where disease may affect the pharmacokinetics of drugs.

Single-step procedure for gas chromatography–mass spectrometry screening and quantitative determination of amphetamine-type stimulants and related drugs in blood, serum, oral fluid and urine samples

We describe a rapid GC/MS assay for amphetamine-type stimulant drugs (ATSs) and structurally related common medicaments in blood, serum, oral fluid and urine samples. The drugs were extracted from their matrices and derivatized with heptafluorobutyric anhydride (HFBA) in a single step, using the following procedure: 100 microl (oral fluid) or 200 microl (blood, serum, urine) of the sample were mixed with 50 microl of alkaline buffer and 500 microl of extraction-derivatization reagent (toluene + HFBA + internal standard), centrifuged, and injected into a GC/MS apparatus. As revealed by the validation data this procedure, with its limit of quantitation being set at 20 ng/ml for oral fluid, 25 ng/ml for blood or 200 ng/ml for urine, is suitable for screening, identification and quantitative determination of the ATSs and related drugs in all the matrices examined. Thus, time-consuming and expensive multiple analyses are not needed, unless specifically required.

Performance characteristics of the Cozart RapiScan Oral Fluid Drug Testing System for opiates in comparison to ELISA and GC/MS following controlled codeine administration

Oral fluid is an interesting alternative matrix for drug testing in many environments, including law enforcement, workplace drug testing, and drug treatment facilities. Performance characteristics of the FDA-cleared, qualitative, Cozart RapiScan Opiate Oral Fluid Drug Testing System (Opiate Cozart RapiScan System or Opiate CRS) were compared to the semi-quantitative Cozart Microplate EIA Opiate Oral Fluid Kit (Opiate ELISA) and to gas chromatography/mass spectrometry (GC/MS). The following oral fluid opiate cutoffs were evaluated: the GC/MS limit of quantification (LOQ) of 2.5 mg/l; 15 microg/l currently used for oral fluid testing in the United Kingdom (UK); 30 microg/l (Opiate CRS cutoff); and 40 microg/l, the proposed Substance Abuse and Mental Health Services Administration (SAMHSA) cutoff. Subjects provided informed consent to participate in this IRB-approved research and resided on the closed research ward throughout the study. Three oral codeine doses of 60 mg/70 kg were administered over a 7-day period. After a 3-week break, subjects received three doses of 120 mg/70 kg within 7 days. Oral fluid specimens (N = 1273) were analyzed for codeine (COD), norcodeine (NCOD), morphine (MOR) and normorphine (NMOR) by GC/MS with an LOQ of 2.5 microg/l for all analytes. MOR and NMOR were not detected in any sample; 26.5% of the specimens were positive for COD and 13.7% for NCOD. Opiate CRS uses a preset, qualitative cutoff of 10 microg/l; this is equivalent to 30 microg/l in undiluted oral fluid as the oral fluid collection process involves a 1:3 dilution with buffer. Sensitivity, specificity, and efficiency of Opiate CRS compared to Opiate ELISA were 98.6, 98.1, and 98.2% at a 30 microg/l cutoff and 99.0, 96.2, and 96.6% at a 40 microg/l cutoff. Compared to the much lower GC/MS LOQ of 2.5 microg/l, sensitivity, specificity and efficiency were 66.8, 99.3 and 90.7%. Increasing the GC/MS cutoff to the current UK level yielded performance characteristics of 81.5% (sensitivity), 99.3% (specificity), and 95.4% (efficiency). Using a GC/MS cutoff identical to the preset Opiate CRS cutoff yielded sensitivity, specificity, and efficiency of 88.5, 99.2, and 97.5%, respectively. At the proposed SAMSHA confirmation cutoff of 40 microg/l, sensitivity increased with little change in specificity and efficiency (91.3% sensitivity, 98.9% specificity, and 97.5% efficiency). Oral fluid is a suitable matrix for detecting drugs of abuse. Opiate CRS, with a 30 microg/l cutoff, is sufficiently sensitive, specific and efficient for oral fluid opiate analysis, performing similarly to Opiate ELISA at the same cutoff, and having performance characteristics >91% when compared to GC/MS at the proposed SAMHSA cutoff.

Oral fluid as a diagnostic tool

Technological advances over the past decades have enabled oral fluid to expand its usefulness in the diagnosis of disease, prediction of disease progression, monitoring of therapeutic drug levels and detection of illicit drugs. The easy non-invasive nature of collection and the relationship between oral fluid and plasma levels make oral fluid a valuable clinical tool. This review describes advances over the past 5 years in the area of oral fluid as a diagnostic tool, its use in therapeutic and illicit drug monitoring, including proposed guidelines for cut-off values, and methods of collection.

Comparisons of self-report data and oral fluid testing in detecting drug use amongst new treatment clients

Drug testing is widely used and employed in diverse contexts, including drug treatment clinics. Building on previous research, this paper aims to (i) compare self-report data and oral fluid (OMT) testing in detecting drug use amongst individuals beginning a new episode of drug treatment and (ii) identify factors that may predict drug users who have discordant self-report and OMT test results. Two hundred and seventy-one new drug treatment clients completed a structured questionnaire that included questions relating to drug use during the preceding 3 days and provided an oral fluid sample that was independently tested for opiates, benzodiazepines, methadone and cannabis. Data were analysed using kappa statistics (Cohen, 1960) and univariate and multivariate logistic regression. Findings indicated a high level of consistency between self-reported drug use and OMT testing. However, agreement varied by drug type and respondents commonly reported consumption that screening failed to identify. Inconsistencies appeared to relate to a number of factors and were not necessarily a function of deliberate distortion by the drug user. Overall, it is concluded that OMT testing is a good indicator of the validity and reliability of drug users' self-report data. Nonetheless, its accuracy might be greater for some drug categories than for others. Equally, further study comparing test results and self-reported drug use amongst different populations and in different contexts is required.