Interpretation and Utility of Drug of Abuse Immunoassays: Lessons From Laboratory Drug Testing Surveys

2010 ◽  
Vol 134 (5) ◽  
pp. 735-739 ◽  
Author(s):  
Stacy E. F. Melanson ◽  
Leland Baskin ◽  
Barbarajean Magnani ◽  
Tai C. Kwong ◽  
Annabel Dizon ◽  
...  
Keyword(s):  
Drug Testing ◽  
Drugs Of Abuse ◽  
False Negative ◽  
Cross Reactivity ◽  
Treatment Programs ◽  
Drug Of Abuse ◽  
Negative Results ◽  
Urine Drug ◽  
Clinically Significant ◽  
Pain Services

Abstract Context.—To assist with patient diagnosis and management, physicians from pain services, drug treatment programs, and the emergency department frequently request that urine be tested for drugs of abuse. However, urine immunoassays for drugs of abuse have limitations. Objective.—To use data from the College of American Pathologists Proficiency Testing Surveys to determine and summarize the characteristics, performance, and limitations of urine immunoassays for drugs of abuse. Design.—Six years of urine drug testing proficiency surveys were reviewed. Results.—Lysergic acid diethylamide and methaqualone are infrequently prescribed or abused and, therefore, testing may be unnecessary. However, implementation of more specific testing for methylenedioxymethamphetamine and oxycodone may be warranted. Each drug of abuse immunoassay exhibits a different cross-reactivity profile. Depending on the cross-reactivity profile, patients with clinically insignificant concentrations of drugs may have false-positive results, and patients with clinically significant concentrations of drugs may have false-negative results. Conclusions.—Laboratory directors should be aware of the characteristics of their laboratories' assays and should communicate these characteristics to physicians so that qualitative results can be interpreted more accurately. Furthermore, manufacturer's claims should be interpreted with caution and should be verified in each organization's patient population, if possible.

Urine drug-testing tampering approaches: Turkish probationers

2020 ◽  
pp. 002580242095645
Author(s):  
Melike Aydoğdu ◽  
Serap Annette Akgür
Keyword(s):  
Screening Test ◽  
Drug Testing ◽  
False Negative ◽  
Drug Abusers ◽  
Eye Drops ◽  
Test Results ◽  
Positive Ratio ◽  
Negative Results ◽  
False Negative Results ◽  
Urine Drug

The growing numbers of individual and social problems associated with drug abuse necessitate new approaches in drug-testing systems. Equally, drug abusers may attempt to invalidate drug testing using different methods such as adulteration, dilution and substitution. This study aims to investigate tampering methods commonly used by Turkish substance-using probationers and evaluate their effects on toxicological drug-testing results. Initially, probationer urinary screening test results and laboratory substitution documents were evaluated to investigate the dilution and substitution attempt. Additionally, an experimental study was carried out by using readily available household products (bleach, vinegar, drain opener, eye drops) for adulteration. The effect of these agents was investigated for 11‐nor‐9‐carboxy-Δ9‐tetrahydrocannabinol (THC–COOH), amphetamine and 3,4-methylenedioxymethamphetamine (MDMA). It was determined that probationers preferred unbranded products (syringes, nylon bottles, etc.) for urine substitution. To detect dilution, screening test results were evaluated along with creatinine values. The variability of mean creatinine values can change the rate of the before-negative and after-positive ratio. For adulteration method, the high amounts of bleach provided false-negative results for THC–COOH and amphetamine, but spiking in any concentration of bleach affected MDMA results, causing a slight increase. Vinegar did not affect the THC–COOH and amphetamine results. However, false-negative results were observed for MDMA, with high amounts of vinegar-spiked urine samples. Drain opener was added in large quantities, and false-negative results were observed for all analytes. Visine eye drops did not have any effect on THC–COOH or amphetamine, but a high quantity of eye drops had a slight decreasing effect for MDMA.

Importance of creatinine analyses of urine when screening for abused drugs

1991 ◽  
Vol 37 (11) ◽  
pp. 1927-1931 ◽  
Author(s):  
P Lafolie ◽  
O Beck ◽  
G Blennow ◽  
L Boréus ◽  
S Borg ◽  
...  
Keyword(s):  
Drug Testing ◽  
Drugs Of Abuse ◽  
False Negative ◽  
Urine Samples ◽  
Heavy Smoker ◽  
Simple Method ◽  
Negative Results ◽  
False Negative Results ◽  
Abused Drugs ◽  
Urine Testing

Abstract We report here a simple method involving urine creatine measurements for testing authenticity and reducing false-negative results in urine testing for drugs of abuse. Urinary creatinine in consecutive patient samples (n = 176) ranged between 0.1 and 31.9 mmol/L (mean 9.8 +/- SD 6.2) and the osmolality in these urines ranged between 49 and 1183 mOsm/kg (mean 595 +/- SD 276). With other consecutive samples in which creatinine was (arbitrarily chosen) less than 4.3 mmol/L (n = 85), the correlation with osmolality was lower. In 10 randomly selected urine samples from different patients, all "clean" for all drugs of abuse in initial immunological drug testing with approved methodology (in which creatinine was less than 4.3 mmol/L and osmolality was less than 200 mOsm/kg), five patients turned out to be drug positive after a simple concentration by volume. In a formerly heavy smoker of cannabis, the excretion of cannabinoids and creatinine was monitored for 93 days. The substances showed very good correlation throughout this period (r = 0.93, P less than 0.001), whereas simple measurements of cannabinoid concentrations would have falsely indicated several relapses of cannabis abuse. Urine samples used in drug-abuse testing should be tested for creatinine; if creatinine is less than 4.0 mmol/L, negative results for drugs may not be valid.

A Prediction Model for Positive Infant Meconium and Urine Drug Tests

2020 ◽  
Author(s):  
Elizabeth A. Simpson ◽  
David A. Skoglund ◽  
Sarah E. Stone ◽  
Ashley K. Sherman
Keyword(s):  
Prediction Model ◽  
Drug Testing ◽  
Clinical Decision Making ◽  
Drugs Of Abuse ◽  
Clinical Decision ◽  
P Value ◽  
Test Characteristics ◽  
Drug Test ◽  
Urine Drug ◽  
Urine Drug Test

Objective This study aimed to determine the factors associated with positive infant drug screen and create a shortened screen and a prediction model. Study Design This is a retrospective cohort study of all infants who were tested for drugs of abuse from May 2012 through May 2014. The primary outcome was positive infant urine or meconium drug test. Multivariable logistic regression was used to identify independent risk factors. A combined screen was created, and test characteristics were analyzed. Results Among the 3,861 live births, a total of 804 infants underwent drug tests. Variables associated with having a positive infant test were (1) positive maternal urine test, (2) substance use during pregnancy, (3) ≤ one prenatal visit, and (4) remote substance abuse; each p-value was less than 0.0001. A model with an indicator for having at least one of these four predictors had a sensitivity of 94% and a specificity of 69%. Application of this screen to our population would have decreased drug testing by 57%. No infants had a positive urine drug test when their mother's urine drug test was negative. Conclusion This simplified screen can guide clinical decision making for determining which infants should undergo drug testing. Infant urine drug tests may not be needed when a maternal drug test result is negative. Key Points

Fluorescent antibody techniques have allowed for the direct identification and enumeration of individual bacteria in environmental samples without requiring prior growth in culture media (Bahlool and Schmidt 1980, Cloete and Steyn 1988, Macario et al. 1989). The technique involves the use of specific antibodies raised against surface markers of defined pure cultures that are either labelled directly with fluorescent dye molecules or via a fluorescent secondary antibody. This approach has yielded important insights into the spatial distribution of microorganisms, but it suffers from a number of disadvantages. For example, expression of the antigen may be influenced by environmental factors; false-positive and false-negative results may be obtained due to cross-reactivity or lack of reaction; non-specific binding of antibodies may result in high levels of background fluorescence; and production of specific antibodies requires a pure culture of the organism of interest (Cloete and de Bruyn Various recombinant DNA techniques have subsequently been developed that are independent of cultivation methods (Fig. 1). These techniques provide ways of detecting and quantifying specific phylogenetic groups of microbes on 16S rDNA sequences, and relevant structural genes provide ways of monitoring microbial populations of environmental and industrial systems. In addition to these tools, a number of emerging technologies such as the use of biomarker genes are being increasingly used to monitor with great precision and accuracy the behaviour of microbes in the environment.

2003 ◽  
pp. 218-219
Keyword(s):  
Recombinant Dna ◽  
Culture Media ◽  
Specific Binding ◽  
Fluorescent Antibody ◽  
False Negative ◽  
Cross Reactivity ◽  
Phylogenetic Groups ◽  
Specific Antibodies ◽  
Negative Results ◽  
Recombinant Dna Techniques

scholarly journals Adulteration of Urine by “Urine Luck”

1999 ◽  
Vol 45 (7) ◽  
pp. 1051-1057 ◽  
Author(s):  
Alan HB Wu ◽  
Ben Bristol ◽  
Karen Sexton ◽  
Gina Cassella-McLane ◽  
Verena Holtman ◽  
...  
Keyword(s):  
Drug Testing ◽  
Drugs Of Abuse ◽  
Spot Test ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyridinium Chlorochromate ◽  
Urine Drug ◽  
Chain Of Custody ◽  
Drug Assays ◽  
Workplace Drug Testing

Abstract Background: In vitro adulterants are used to invalidate assays for urine drugs of abuse. The present study examined the effect of pyridinium chlorochromate (PCC) found in the product “Urine Luck”. Methods: PCC was prepared and added to positive urine controls at concentrations of 0, 10, 50, and 100 g/L. The controls were assayed for methamphetamine, benzoylecgonine (BE), codeine and morphine, tetrahydrocannabinol (THC), and phencyclidine (PCP) with the Emit II (Syva) and Abuscreen Online (Roche) immunoassays, and by gas chromatography/mass spectrometry (GC/MS). Two tests were also developed to detect PCC in urine: a spot test to detect chromate ions using 10 g/L 1,5-diphenylcarbazide as the indicator, and a GC/MS assay for pyridine. We tested 150 samples submitted for routine urinalysis, compliance, and workplace drug testing for PCC, using these assays. Results: Response rates decreased at 100 g/L PCC for all Emit II drug assays and for the Abuscreen morphine and THC assays. In contrast, the Abuscreen amphetamine assay produced apparently higher results, and no effect was seen on the results for BE or PCP. The PCC did not affect the GC/MS recovery of methamphetamine, BE, PCP, or their deuterated internal standards, but decreased GC/MS recovery of the opiates at both intermediate (50 g/L) and high (100 g/L) PCC concentrations and apparent concentrations of THC and THC-d3 at all PCC concentrations. Two of 50 samples submitted for workplace drug testing under chain-of-custody conditions were positive for PCC, whereas none of the remaining 100 specimens submitted for routine urinalysis or compliance drug testing were positive. Conclusions: PCC is an effective adulterant for urine drug testing of THC and opiates. Identification of PCC use can be accomplished with use of a spot test for the oxidant.

Financial viability of screening for drugs of abuse

1995 ◽  
Vol 41 (5) ◽  
pp. 805-808 ◽  
Author(s):  
M A Peat
Keyword(s):  
Drug Testing ◽  
Drugs Of Abuse ◽  
The United States ◽  
Economic Benefits ◽  
Postal Service ◽  
Test Results ◽  
United States Postal Service ◽  
Financial Benefits ◽  
Urine Drug Testing ◽  
Urine Drug

Abstract Urine drug testing is now a common practice in the American workplace; a recent survey indicated that > 90% of companies with > 5000 employees have some type of testing program. These programs have indeed reduced the rate of drug-positive test results; for example, recent data from the Federal Aviation Agency show that the rate for 1993 was 0.82% compared with 0.95% for 1992. Many corporations have stated that urine drug testing, as a component of a substance abuse policy, results in significant savings, e.g., from decreased absenteeism and turnover. The United States Postal Service recently completed a longitudinal study on the economic benefits and found that, over the average tenure of an annual intake of employees, there were savings of more than $100 million. Although this study clearly demonstrates the financial benefits of preemployment drug testing, the decision to test is not based solely on this but also on the regulatory environment and on the potential impact of a major accident attributable to the use of drugs or alcohol in the workplace.

scholarly journals Effect of urine adulterants on commercial drug abuse screening test strip results

2020 ◽  
Vol 71 (1) ◽  
pp. 87-93
Author(s):  
Ivana Rajšić ◽  
Dragana Javorac ◽  
Simona Tatović ◽  
Aleksandra Repić ◽  
Danijela Đukić-Ćosić ◽  
...  
Keyword(s):  
Drug Abuse ◽  
False Negative ◽  
Test Strip ◽  
Lemon Juice ◽  
Screening Tests ◽  
Urine Specimen ◽  
Test Results ◽  
Negative Results ◽  
Urine Drug ◽  
Validity Tests

AbstractImmunochromatographic strips for urine drug screening tests (UDSTs) are common and very suitable for drug abuse monitoring, but are also highly susceptible to adulterants kept in the household, which can significantly alter test results. The aim of this study was to see how some of these common adulterants affect UDST results in practice and whether they can be detected by sample validity tests with pH and URIT 11G test strips. To this end we added household chemicals (acids, alkalis, oxidizing agents, surfactants, and miscellaneous substances) to urine samples positive for amphetamine, 3,4-methylenedioxymethamphetamine (MDMA), tetrahydrocannabinol, heroin, cocaine, or benzodiazepines (diazepam or alprazolam) and tested them with one-component immunochromatographic UDST strips. The UDST for cocaine resisted adulteration the most, while the cannabis test produced the most false negative results. The most potent adulterant that barely changed the physiological properties of urine specimens and therefore escaped adulteration detection was vinegar. Besides lemon juice, it produced the most false negative test results. In conclusion, some urine adulterants, such as vinegar, could pass urine specimen validity test and remain undetected by laboratory testing. Our findings raise concern about this issue of preventing urine tampering and call for better control at sampling, privacy concerns notwithstanding, and better sample validity tests.

scholarly journals Sensitivity of prostate cancer foci using 1.5 T multiparametric magnetic resonance imaging

2020 ◽  
Author(s):  
Suguru Ito ◽  
SEI NAITO ◽  
Takafumi Narisawa ◽  
Mayu Yagi ◽  
Yuta Kurota ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Prostate Cancer ◽  
Magnetic Resonance ◽  
False Negative ◽  
Resonance Imaging ◽  
Prostate Imaging ◽  
Multiparametric Magnetic Resonance Imaging ◽  
Negative Results ◽  
False Negative Results ◽  
Clinically Significant

Abstract Background The detection of prostate cancer (CaP) has increasingly being carried out by multiparametric magnetic resonance imaging (mpMRI). Despite many previous studies, the sensitivity for clinically significant CaP (csCaP) was high, information on mpMRI false-negative lesions is limited. Therefore, the aim of this study was to evaluate the use and limitations of mpMRI in CaP. Methods A total of 228 CaP foci in 100 patients who underwent 1.5 T mpMRI and radical prostatectomy between December 2015 and June 2017 were retrospectively analyzed. The sensitivities of CaP foci, csCaP, and index tumors (ITs) were measured. Clinically significant CaP was defined into two categories based on the Gleason score (GS): csCaP/GS ≥ 3 + 4 (GS ≥ 3 + 4 or diameter > 10 mm) and csCaP/GS ≥ 4 + 3 (GS ≥ 4 + 3 or diameter > 10 mm). In addition, the characteristics of false-negative lesions were identified. The Prostate Imaging Reporting and Data System version 2 was used to determine an mpMRI positive lesion, defined as a lesion having a score of ≥ 3. Results The sensitivity of all legions, csCaP/GS ≥ 3 + 4, csCaP/GS ≥ 4 + 3, and ITs were 61.4%, 75.8%, 83.0%, and 91%, respectively. There were 91 lesions that were mpMRI false, 40% of which were csCaP/GS ≥ 3 + 4. There were three lesions with a GS of ≥ 8 and ≥ 10 mm in the false-negative results. Conclusions mpMRI can highly detect ITs and csCaP/GS ≥ 4 + 3; however, a few large and high-GS CaPs constitute undetectable lesions in 1.5 T mpMRI.

scholarly journals Intradermal Drug Testing following Anaphylactoid Reactions during Anaesthesia

1981 ◽  
Vol 9 (4) ◽  
pp. 381-386 ◽  
Author(s):  
David Sage
Keyword(s):  
Drug Testing ◽  
False Negative ◽  
Skin Tests ◽  
Positive Information ◽  
Positive Skin ◽  
Intradermal Testing ◽  
Negative Results ◽  
False Negative Results ◽  
Intravenous Anaesthetic ◽  
Anaphylactoid Reactions

Intradermal testing of intravenous anaesthetic drugs was performed on 34 patients following acute anaphylactoid reactions during anaesthesia. Twenty-three patients had positive skin tests and 18 of these were positive for a single drug. Muscle relaxants were the drugs implicated most commonly. Intradermal testing is safe and provides useful and often specific positive information, but false-negative results probably occur.

scholarly journals Interpretation and Utility of Drug of Abuse Screening Immunoassays: Insights From Laboratory Drug Testing Proficiency Surveys

2019 ◽  
Vol 144 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Matthew D. Krasowski ◽  
Gwendolyn A. McMillin ◽  
Stacy E. F. Melanson ◽  
Annabel Dizon ◽  
Barbarajean Magnani ◽  
...  
Keyword(s):  
Health Care Providers ◽  
Drug Testing ◽  
Cross Reactivity ◽  
Prescription Drug Abuse ◽  
Variable Cross ◽  
Care Providers ◽  
Synthetic Opioids ◽  
Urine Drug Testing ◽  
Urine Drug ◽  
Abused Drugs

Context.— Urine drug testing is frequently ordered by health care providers. Immunoassays are widely used for drug testing, yet have potential limitations, including variable cross-reactivity. The last decade has seen worsening of a prescription drug abuse epidemic. Objective.— To use data from a College of American Pathologists proficiency testing survey, Urine Drug Testing, Screening, to determine and summarize the characteristics, performance, and limitations of immunoassays. Design.— Seven years of proficiency surveys were reviewed (2011–2017). Results.— Rapid growth was seen in participant volumes for specific immunoassays for synthetic opioids (eg, buprenorphine, fentanyl, oxycodone) and 3,4-methylenedioxymethamphetamine (“ecstasy”). Participant volumes remained high for immunoassays targeting less commonly abused drugs such as barbiturates and phencyclidine. For opiate immunoassays, the number of laboratories using a 2000 ng/mL positive cutoff remained stable, and an increasing number adopted a 100 ng/mL cutoff. Opiate and amphetamine immunoassays showed high variability in cross-reactivity for drugs other than the assay calibrator. Assays targeting a single drug or metabolite generally performed well on drug challenges. Conclusions.— Survey results indicate strong clinical interest in urine drug testing and some adoption of new assays. However, urine drug testing availability does not parallel prevailing patterns of drug prescribing and abuse patterns. In particular, specific immunoassays for synthetic opioids and a lower positive cutoff for opiate immunoassays may be underused, whereas immunoassays for barbiturates, methadone, propoxyphene, and phencyclidine may be overused. Laboratories are encouraged to review their test menu, cutoffs, and assay performance and adjust their test offerings based on clinical needs and technical capabilities.

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