Drugs Of Abuse In Urine Research Articles

Detection Time of Drugs of Abuse in Urine

Estimating the detection time of a drug in urine is complex because of many different influencing factors and the lack of experimental data. Detection times vary depending on dose and route of administration, metabolism and characteristics of the screening and confirmation assays.Using a cut-off value of 1000 ng/mL, urinary samples can be positive for amphetamine for up to 5 days after intake of the drug. At the lower 300 ng/mL cut-off, amphetamine will be detectable one day longer. Very few data are available for designer amphetamines.After smoking one marijuana cigarette, THCCOOH (9-carboxy-Δ9 tetrahydrocannabinol) is detectable (using a screening cut-off of 50 ng/mL) for 2-4 days. More frequent use will be detectable for almost 1 month, exceptionally 3 months.Immunoassays to detect cocaine are targeted against the metabolite benzoylecgonine and use a cut-off of 300 ng/mL. An intravenous dose of 20 mg cocaine can be detected for 1.5 days. Street doses (administered via different routes) are detectable up to 1 week, and extremely high doses up to 3 weeks.Heroin rapidly metabolises to 6-acetylmorphine and morphine. Immunoassays for heroin are calibrated with morphine but important cross-reactivity occurs and positive results must be confirmed by GC-MS. Experimental data for total morphine using a cut-off of 300 ng/mL suggest a detection time of 1 to 1.5 days for relatively low doses of heroin (3-12 mg) administered via IV, IN or IM route.

Evaluation of detection techniques and laboratory proficiency in testing for drugs of abuse in urine: an external quality assessment scheme using clinically realistic urine samples. Steering Committee for the United Kingdom National External Quality Assessment Scheme for Drugs of Abuse in Urine.

Techniques for the detection of drugs of abuse were compared using data from 43 urine samples distributed by the United Kingdom National External Quality Assessment Scheme. Drug mixtures simulated clinical specimens and contained drugs at the following median concentrations: amphetamine 1.6 mg/L (six samples), barbiturates 1.7 mg/L (six samples), benzoylecgonine 0.6 mg/L (eight samples), benzodiazepines 1.6 mg/L (four samples), cannabinoids 59 micrograms/L (four samples), methadone 1.7 mg/L (11 samples) and morphine 1.7 mg/L (seven samples). Significant lack of sensitivity was demonstrated for one or more analytes by all chromatographic techniques, including gas chromatography with mass spectrometry. Commercial immunoassay kits exhibited higher sensitivity, though some assays performed significantly less well than others. Significant non-specificity was also a greater problem for chromatographic techniques compared with immunoassays in samples containing therapeutic agents not structurally related to abused compounds. In the presence of therapeutic interferents structurally related to the test compounds, false positive reports for illicit materials increased from < 1% to > 6%. Use of confirmatory tests significantly reduced the incidence of both false negative and false positive reports.

Prevalence of drugs of abuse in urine of drivers involved in road accidents in France: a collaborative study

This collaborative, anonymous, case-control study was intended to determine the prevalence of opiates, cocaine metabolites, cannabinoids and amphetamines in the urine of drivers injured in road accidents and to compare these values with those of non-accident subjects (“patients”) in France. Recruitment was performed nationwide in the emergency departments of five hospitals and comprised 296 “drivers” aged 18 to 35 and 278 non-traumatic “patients” in the same age range. Females represented 28.4% of “drivers” and 44.2% of “patients.” Screening for drugs in urine was performed by fluorescence polarization immunoassays in each center. Each positive result was verified using gas chromatography-mass spectrometry (GC-MS), in a single laboratory. Statistical analysis comprised single-step logistic regression and simultaneously took account of confounding factors and the final differences in prevalence values between the two populations or different subgroups. Cannabinoids were found in 13.9% of drivers (16.0% of males and 8.3% of females, p No causal relationship between drugs and accidents should be inferred from this retrospective study. Nevertheless, the high prevalence of cannabis and opiate (licit or illicit) use in young people, whether injured drivers or patients, has potential implications for road traffic safety in France. Cocaine and amphetamines did not appear to be a major problem, unlike the experience in other countries.

Prevalence of Drugs of Abuse in Urine of Drivers Involved in Road Accidents in France: A Collaborative Study

The collaborative, anonymous, case-control study was intended to determine the prevalence of opiates, cocaine metabolites, cannabinoids and amphetamines in the urine of drivers injured in road accidents and to compare these values with those of non-accident subjects ("patients") in France. Recruitment was performed nationwide in the emergency departments of five hospitals and comprised 296 "drivers" aged 18 to 35 and 278 non-traumatic "patients" in the same age range. Females represented 28.4% of "drivers" and 44.2% of "patients." Screening for drugs in urine was performed by fluorescence polarization immunoassays in each center. Each positive result was verified using gas chromatography-mass spectrometry (GC-MS), in a single laboratory. Statistical analysis comprised single-step logistic regression and simultaneously took account of confounding factors and the final differences in prevalence values between the two populations or different subgroups. Cannabinoids were found in 13.9% of drivers (16.0% of males and 8.3% of females, p < 0.05) and 7.5% of patients (12.3% of males, 1.6% of females, p < 0.0001); only in females was this prevalence higher in injured drivers than in patients (p < 0.05). Opiates were present in 10.5% of drivers' and 10.4% of patients' urine samples (NS), and were more frequent in urine samples positive for cannabinoids, in drivers (p < 0.01) as well as in patients (p < 0.001). The prevalence of cocaine metabolites in drivers and patients was 1.0 and 1.1% and that of amphetamines 1.4 and 2.5%, respectively. No causal relationship between drugs and accidents should be inferred from this retrospective study. Nevertheless, the high prevalence of cannabis and opiate (licit or illicit) use in young people, whether injured drivers or patients, has potential implications for road traffic safety in France. Cocaine and amphetamines did not appear to be a major problem, unlike the experience in other countries.

Improved cross-reactivity to alpha OH triazolam in the BMC CEDIA DAU urine benzodiazepine assay.

Immunoassays designed to detect use of older benzodiazepines such as oxazepam or diazepam often cannot detect triazolam use because of the low doses of triazolam administered, rapid biotransformation to metabolites with poor cross-reactivities, and the small amount of alpha OH triazolam glucuronide excreted in the urine. Previous studies have demonstrated that certain immunoassays have high cross-reactivity to alpha OH triazolam but are unable to detect therapeutic triazolam use in urine. The objectives of this study were to characterize the immunoreactivity toward alpha OH triazolam in the reformulated cloned enzyme donor immunoassay (CEDIA) drug abuse urine benzodiazepine assay and to measure the immunoreactivity of urine specimens from subjects who were administered single oral doses of triazolam. Alpha OH triazolam standards were prepared in drug-free urine and the new CEDIA assay gave a positive result at concentrations from 100 to 200 ng/ml, which indicates an eight-fold improvement in CEDIA cross-reactivity to alpha OH triazolam standards in the reformulated CEDIA assay. With a 200 ng/ml cut-off, 4/30 of the urine specimens screened positive for benzodiazepines without enzymatic hydrolysis and 6/30 after enzymatic hydrolysis. When using an in-house 100 ng/ml nitrazepam cut-off calibrator, 10/30 urine specimens were positive in the reformulated CEDIA assay without hydrolysis and 22/30 were positive with enzymatic hydrolysis before screening.

New developments in particle-based immunoassays: Introduction

Abstract

CEDIA for Screening Drugs of Abuse in Urine and the Effect of Adulterants

The performance of the Microgenics CEDIA DAU assays for screening amphetamines, barbiturates, benzodiazepines, cocaine, opiates, phencylidine (PCP), and tetrahydrocannabinol (THC) was evaluated on the Boehringer Mannheim/Hitachi 717 in urine. Limits of detection ranged from 0.6 ng/mL for PCP, to 34.1 ng/mL for benzodiazepines. The average within run and total precision for these assays ranged from 1.3 to 7.3% for controls at cutoff concentrations, and control values at -25% and +25% of cutoffs. The rate separations by CEDIA between the negative and cutoff calibrators for all drugs were greater than corresponding EMIT II (Syva Co.) assays. The relative sensitivity and specificity of CEDIA as compared to EMIT II were 95.6 and 98.8%, respectively, on 13,535 urine samples. All positive samples, and those samples producing discordant results between the assays were confirmed by quantitative gas chromatography/mass spectrometry (GC/MS). Using SAMHSA cutoff limits (and including barbiturates and benzodiazepines at 300 ng/mL), the relative sensitivity and specificity of CEDIA vs. EMIT II were 96.7 and 98.8%, respectively. The overall sensitivity of CEDIA vs. GC/MS was 98.9% with 179 false positives, as compared to 96.2% with 189 false positives for EMIT II vs. GC/MS. The effect of adulterants added to urine to potentially invalidate screening results was also tested. CEDIA produced strong interferences for most drug assays in the presence of glutaraldehyde, detergent, and high concentrations of bleach and Drano. Minimal or selective interferences were seen with golden seal tea lemon juice, Visine, and low concentrations of bleach and Drano. Essentially no interference was observed with bicarbonate, sodium chloride, and vinegar.

NIST reference materials to support accuracy in drug testing

Substance abuse is a major problem worldwide. There is considerable emphasis placed upon testing individuals for evidence of use of controlled substances. Because the consequences of a positive test can be quite severe, laboratories conducting such tests must rigorously follow a carefully designed quality assurance program. Such a QA program should include use of reference materials to assure that the methods used to detect and quantify drugs are providing accurate results. The National Institute of Standards and Technology (NIST) supports accuracy in drugs of abuse testing by providing Standard Reference Materials (SRMs) with certified concentrations of drugs of abuse in urine- and hair-based reference materials. NIST, working in collaboration with the College of American Pathologists (CAP), has developed urine-based SRMs for marijuana metabolite, cocaine metabolite, morphine and codeine, and morphine glucuronide and CAP Reference Materials for amphetamines and phencyclidine. Certification measurements performed at NIST involve two independent methods for each analyte, one of which always uses GC/MS with the other usually being an LC method with either MS or UV detection. Work has recently been completed on a seven component drug in urine SRM. In addition NIST conducts research in the analysis of hair for drugs of abuse. To assist laboratories testing hair for that purpose, NIST has developed two drugs in hair reference materials.

External quality assessment of techniques for the detection of drugs of abuse in urine.

Five chromatographic and six immunoassay techniques were compared using data reported by 131 participants in the UK National External Quality Assessment Scheme for Drugs of Abuse in Urine. Twenty five samples were studied containing none or one of three concentrations of amphetamine, barbiturates, benzodiazepines, benzoylecgonine, methadone and morphine. Technique sensitivity and specificity achieved with realistic clinical samples of 25 mL vol were assessed as the percentage of true positive and true negative tests, respectively. Thin-layer chromatography was inadequate for the detection of several analytes, the sensitivity for 0.5 mg/L of benzoylecgonine being < 30%, and for 1.5 mg/L of amphetamine < 86%. Gas chromatography with mass spectrometry was significantly less sensitive than other techniques for the detection of 0.5 mg/L of benzoylecgonine (71%) and 1.5 mg/L of morphine (88%). High-performance liquid chromatography was the most sensitive for amphetamine. Immunoassays performed well when operating above their specified cut-off concentrations but, because they are directed to quinalbarbitone showed reduced cross-reactivity with amylobarbitone, the barbiturate more commonly prescribed in the UK.

Identification and quantitation of drugs of abuse in urine using the generalized rank annihilation method of curve resolution

A rapid analytical method which is of practical use for the identification and quantitation of drugs of abuse in urine using HPLC with a diode-array detection is described. Because the method utilizes mathematical resolution of partially resolved peaks, greatly simplified sample preparation procedures and very short run times can be used. The generalized rank annihilation method (GRAM) is used to eliminate response due to unknown background peaks and separate partially resolved peaks. An optimized gradient elution program was found for which morphine, phenylpropanolamine, ephedrine, benzoylecgonine, lidocaine, cocaine, diphenhydramine, nortriptyline, norpropoxyphene, nordiazepam, codeine, d-amphetamine, meperidine, and amitriptyline elute from the HPLC column in less than 8.5 min. A commercially available system for HPLC analysis of drugs of abuse is currently available, however, the commercially available system takes 21 min to complete its analysis. Two modified sample pre-treatment methods were also developed to simplify sample treatment procedures substantially. In this paper, The GRAM technique is shown to be extremely powerful in identifying drugs of abuse from large overlapping peaks.

Decreased signal in Emit assays of drugs of abuse in urine after ingestion of aspirin: potential for false-negative results

During routine drug analysis with the Syva d.a.u. Emit immunoassays we observed a high frequency of urines with lower rates of changes in absorbance (delta A R) than the rate for a drug-free urine calibrator. Many of these urines contained salicylates. Among 40 urines with apparent salicylate concentrations between 15 and 420 mg/dL tested for benzoylecgonine (BE), 20 had delta A R < -4 (range +2 to -28 mA/min). The rates decreased with increasing salicylate: delta A R = -0.057 x (salicylate, mg/dL) -0.22 mA/min (r = 0.85, n = 40, P < 0.01). Urines from 100 control subjects (no salicylate) had mean +/- SD delta A R values of -1.05 +/- 2.2 mA/min (range +3 to -7; only two were < -4 mA/min). Although direct addition of salicylic acid (200 mg/dL) to urine specimens did not reproduce the negative bias, ingestion of aspirin (acetylsalicylic acid) did by -0.09 mA/min per 1 mg/dL (72.4 mumol/L) salicylate. Negative biases observed for other Emit d.a.u. assays after salicylate ingestion lead us to conclude that ingestion of therapeutic doses of aspirin may cause false-negative results for drug screens in urines by this technology.

Deficient performance of drugs of abuse testing in Sweden: an external control study.

Testing for drugs of abuse in urine is usually performed in two steps; after initial screening positive findings are confirmed with specific chromatographic techniques. The use of different methods with different cut-off levels, may lead to variable results in a test sample containing a drug. Sixty-eight Swedish laboratories were enrolled in an external quality study and received three control samples. The laboratories were instructed to perform only in-house tests for amphetamines, benzodiazepines, cannabinoids, cocaine and opiates. Nineteen out of the 68 laboratories reported fully correct results. Thirty reported one o more false positive drug findings. One laboratory performing confirmation with gas chromatography--mass spectrometry reported a false positive finding of amphetamines in the sample containing ephedrine. Since testing for drugs of abuse in urine is a delicate matter, with both medical and legal implications, such testing should be performed with a zero rate of false positive results. Routine use of specific methods for confirmation should be used since performance of these laboratories was better in this study. It is concluded that there is a need to continuously measure the level of quality of laboratories by a program for external quality control.

Gas Chromatography/Tandem Mass Spectrometry Measurement of Δ9-Tetrahydrocannabinol, Naltrexone, and Their Active Metabolites in Plasma

The combination of gas chromatography and mass spectrometry (GC/MS) is generally recognized as offering the best sensitivity and specificity for the detection and measurement of drugs and their metabolites in biological specimens. This finding has resulted in the widespread use of GC/MS in many areas of pharmacology and toxicology. However, a GC/MS assay can be performed in many ways, depending upon the specific requirements of the analytical tasks. For example, pharmacokinetic studies generally employ chemical ionization and single-ion monitoring to obtain optimum sensitivity, whereas GC/MS methods for confirmation of the presence of drugs of abuse in urine most often use electron ionization and multiple-ion monitoring to obtain conclusive results. Another example is the increasing use of the combination of gas chromatography and tandem mass spectrometry (GC/MS/MS) for analyses requiring sensitivities better than nanograms per milliliter. Examples of the application of GC/MS and GC/MS/MS methods for the detection of delta 9-tetrahydrocannabinol, naltrexone, and their active metabolites are described and compared in terms of sensitivity, specificity, and unique features.

Effect of Freezing on the Concentration of Drugs of Abuse in Urine

Benzoylecgonine, 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-acid), phencyclidine, codeine, morphine, amphetamine, methamphetamine, and lysergic acid diethylamide were dissolved in urine, stored frozen in plastic tubes at -16 to -18 degrees C, defrosted, transferred to other tubes, and analyzed by gas chromatography/mass spectrometry (GC/MS); no significant loss of compound was observed, except for THC-acid, which showed an average loss of 11%, ranging from 0 to 34% of the total concentration. The loss is attributed to the decrease in solubility of the compound and to adherence to the side of the container during freezing.

Performance of Techniques Used to Detect Drugs of Abuse in Urine

Performance of Techniques Used to Detect Drugs of Abuse in Urine

Evaluation of the Syva ETS Plus urine drug and serum ethanol analyzer.

The Syva ETS is an automated system designed for analysis of drugs of abuse in urine. Recently, the Syva Company has upgraded this system to the ETS Plus, which is capable of analyzing ethanol in urine, serum, or plasma. We evaluated the new ETS Plus for urine screening of barbiturates, benzodiazepines, cocaine metabolite, opiates, and phencyclidine. Results of 505 patient sample assays obtained by ETS Plus were compared with those of ETS. There were only four discrepant results which had absorbance rates close to the low calibrator cutoff values. The within-run precision of the ETS Plus Ethyl Alcohol Assay yielded a CV of 2.6% at a target value of 1.00 g/L (1.06 +/- 0.03 g/L, n = 32) and a CV of 3.2% at a target value of 0.40 g/L (0.42 +/- 0.01 g/L, n = 30). The linear regression analysis of 30 patient serum ethanol results by the ETS Plus and by gas chromatography yielded y = 0.939 x + 0.03 g/L. The software modifications in the new ETS Plus allow the accurate quantitation of ethanol in serum and reliable detection of drugs of abuse within the same batch.

The effects of adulterating agents on FPIA analysis of urine for drugs of abuse.

A variety of chemical agents were evaluated to determine their effects on fluorescence polarization immunoassays for drugs of abuse. Sixteen different agents, at concentrations up to 10%, were tested against urine assays for cannabinoids, cocaine (metabolite), amphetamines, opiates, phencyclidine (PCP), and barbiturates. The potential to cause both false positive and false negative results was evaluated, and assays were performed one and seven days after sample adulteration to simulate different collection/testing formats. All six drug assays were susceptible to one or more adulterating agents, but the degree varied considerably between assays. The cannabinoid assay was most susceptible to adulterant-induced false negative results, and the barbiturate assay was most susceptible to false positive results. The remaining assays demonstrated relatively few, but characteristic effects, some of which were attributable to drug degradation and others to assay interference. Although the results of pH measurement on adulterated samples verified its utility in identifying some samples adulterated with interfering agents, other adulterants that cause substantial effects would not be identified by pH measurements alone.

Simultaneous Detection of Seven Drugs of Abuse by the TriageTM Panel for Drugs of Abuse

This novel, competitive immunoassay simultaneously detects seven drugs of abuse in urine. A urine sample is placed in contact with lyophilized reagents, the reaction mixture is allowed to come to equilibrium (10 min), and then the whole mixture is applied to a solid phase that contains various immobilized antibodies in discrete drug-class-specific zones. After a washing step, the operator visually examines each zone for the presence of a red bar. The method incorporates present threshold concentrations that are independent for each drug. In the absence of drug or in the presence of drug in quantities less than the threshold concentration, no colored bar is visible. Samples containing drug(s) at or above the threshold concentration cause a red bar to appear for the appropriate drug(s). Positive and negative procedural control zones are incorporated into each determination. The performance of the assay methodology matches that of instrumented immunoassay systems.

Solid-phase extraction and HPLC-UV confirmation of drugs of abuse in urine.

A series of six liquid chromatographic methods were developed to confirm the presence of six classes of drugs of abuse in urine. The chromatographic separations were performed with a reversed-phase C8 column, except in the case of morphine, which was separated on a normal phase column. Isocratic and gradient elutions, ion pair technique, and UV detection were employed. Sample pretreatment involved the extensive application of solid-phase extractions and liquid-liquid extractions on solid supports. The specificity and sensitivity enabled the confirmation of morphine, benzoylecgonine, THC-COOH, amphetamine, and methamphetamine, six barbiturates, and nine benzodiazepines screened positive by EMIT in urine.

Performance of techniques used to detect drugs of abuse in urine: study based on external quality assessment

Twenty-five samples of lyophilized urine from the U.K. External Quality Assessment Scheme for Drugs of Abuse were analyzed by an average of 95 laboratories between April 1987 and December 1989. Samples contained mixtures of analytes and included replicated concentrations of morphine, methadone, amphetamine, and cocaine at 0, 1, 2, and 5 mg/L and of benzoylecgonine at 0, 0.4, 1, 2, and 4 mg/L. Some chromatographic techniques were inadequate for detecting morphine, amphetamine, cocaine, and benzoylecgonine at the lower concentrations of analytes studied: gas-liquid chromatography was least sensitive for morphine; in-house thin-layer chromatography (TLC) was least sensitive for the other analytes. Few significant differences in specificity were detected between techniques, although significant interference from structurally related compounds was demonstrated in assays of morphine, methadone, and amphetamine. Exceptions were the Boehringer (BCL) test for opiates and TLC applied to amphetamine and benzoylecgonine, which demonstrated considerable lack of specificity.