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

Endogenous opiates and behavior: 2007

This paper is the thirtieth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2007 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Current developments in drug testing in oral fluid

In the last few years, significant developments have occurred on the key issues involved in oral fluid drug testing. New pharmacokinetic studies have been conducted, optimal cutoffs have been proposed, and new studies have examined the correlation between oral fluid drug concentrations and impairment. Recent studies (eg, the discovery of the presence of THC-COOH in oral fluid) can contribute to solve the issue of false-positive results caused by passive exposure to marijuana. Reliable point-of-care drug testing is still problematic, especially for cannabinoids and benzodiazepines. To date, there is no device that allows both reliable and practical point-of-care testing. The importance of liquid chromatography- tandem mass spectrometry in confirmation analysis has increased over the last several years. It can be expected that this trend will continue because the low sample volumes make simultaneous detection of different drug classes with limited sample preparation necessary. Literature on proficiency testing to ensure reliability and comparability of results is limited. Oral fluid has become an important sample type in driving under the influence research, and the first legal random drug testing program in oral fluid since 2004 has been organized in Victoria. It can be expected that the role of oral fluid as an alternative matrix will keep increasing in the future.

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).

Modern instrumental methods in forensic toxicology

This article reviews modern analytical instrumentation in forensic toxicology for identification and quantification of drugs and toxins in biological fluids and tissues. A brief description of the theory and inherent strengths and limitations of each methodology is included. The focus is on new technologies that address current analytical limitations. A goal of this review is to encourage innovations to improve our technological capabilities and to encourage use of these analytical techniques in forensic toxicology practice.

Bioanalytical procedures for determination of drugs of abuse in oral fluid

Recent advances in analytical techniques have enabled the detection of drugs and drug metabolites in oral fluid specimens. Although GC-MS is still commonly used in practice, many laboratories have developed and successfully validated methods for LC-MS(-MS) that can detect a large number of compounds in the limited sample volume available. In addition, several enzyme immunoassays have been commercialized for the detection of drugs of abuse in oral fluid samples, enabling the fast screening and selection of presumably positive samples. A number of concerns are discussed, such as the variability in the volume of sample collected and its implications in terms of quantitative measurements, and the drug recoveries of the many different specimen collection systems on the market. Additional considerations that also receive attention are the importance of providing complete validation data with respect to analyte stability, matrix effect, and the choice of collection method.

Interpretation of oral fluid tests for drugs of abuse

Oral fluid testing for drugs of abuse offers significant advantages over urine as a test matrix. Collection can be performed under direct observation with reduced risk of adulteration and substitution. Drugs generally appear in oral fluid by passive diffusion from blood, but also may be deposited in the oral cavity during oral, smoked, and intranasal administration. Drug metabolites also can be detected in oral fluid. Unlike urine testing, there may be a close correspondence between drug and metabolite concentrations in oral fluid and in blood. Interpretation of oral fluid results for drugs of abuse should be an iterative process whereby one considers the test results in the context of program requirements and a broad scientific knowledge of the many factors involved in determining test outcome. This review delineates many of the chemical and metabolic processes involved in the disposition of drugs and metabolites in oral fluid that are important to the appropriate interpretation of oral fluid tests. Chemical, metabolic, kinetic, and analytic parameters are summarized for selected drugs of abuse, and general guidelines are offered for understanding the significance of oral fluid tests.