Justin L Poklis

Virginia Commonwealth University
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Articles (10)

There has been a surge in the presence and use of cannabinoids since the federal legalization of hemp (Agricultural Improvement Act of 2018). This increase is attributed not only to the use of ∆9-tetrahydrocannabinol (∆9-THC) and cannabidiol, the most abundant phytocannabinoid components of cannabis and hemp, respectively, but also to the use of many other emerging THC analogs. Structurally, these analogs are similar to ∆9-THC. Urine specimens for drug analysis are often collected offsite and transported to a laboratory for analysis. Screening assays are usually the first step in urine drug testing. These assays are usually qualitative and automated, which for negative specimens, reduce cost and reporting time. The stability of ∆9-THC and its metabolites has been known for some time; however, the stability of emerging analogs has not been elucidated, and therefore, assuming equivalent storage stability can be erroneous. Previous work assessed the cross-reactivity of ∆8-THC and its major metabolites, the ∆10-THC chiral analogs and the chiral 11-COOH-hexahydrocannabinol analogs. Stability was assessed for each analyte at a concentration two times greater than the analytes’ determined decision point. Samples were prepared in drug-free urine at three different pHs (4.5, 7 and 9) and stored at three different temperatures (4°C, 20°C and 45°C) in triplicate. Samples were analyzed utilizing the Lin-Zhi International Cannabinoids Enzyme Immunoassay cannabinoid screening kit calibrated at the 25 ng/mL cut-off. Overall, the cannabinoid analogs produced diminishing instrument responses depending on pH and temperature. The parent analogs were not detected after a single day at 45°C regardless of pH. In general, carboxylic acid analogs at the acidic pH (4.5) produced diminished instrument responses when compared to their counterparts stored at neutral (7) and basic (9) pH. The time, storage temperature and pH of urine specimens may affect the screening results of specimens collected for cannabinoid drug screening.

Year:

2023

Legal professionals and others have suggested that vaping electronic cigarettes (e-cigs) prior to or during ethanol breath testing may produce false positives. Preliminary breath tests (PBTs) and evidentiary breath tests (EBTs) measure ethanol in exhaled breath and standardized field sobriety tests (SFSTs) are used to assess impairment. Ethanol has been identified in e-cig liquids (e-liquids). Presented are a series of experiments designed to determine the mechanics of vaping ethanol using an e-cig and the effects of vaping ethanol on the SFSTs and breath tests used by law enforcement officers (LEO). Twelve participants (five females, age: 21–32 and seven males, age: 21–55), vaped either one or ten puffs of an e-liquid (0% or 20% ethanol). LEOs assessed impairment using SFSTs (12 and 42 min), PBTs (<1, 27, 32, 37 and 57 min) and EBTs (2, 29, 34, 39 and 59 min) post-vaping. A self-assessment test was administered post-vaping (22 and 52 min). Baseline responses for all measures were collected prior to vaping. Results demonstrated that ethanol in the e-liquids was aerosolized by e-cigs and produced particles that could reach the deep lung tissue based on mean-mass diameter. Ethanol was detected by PBT <3 min after participants vaped one (0.007–0.030 g/210 L) or ten puffs (013–0.074 g/210 L) of a 20% ethanol e-liquid. Ethanol was not detected by PBT at any subsequent time point. Ethanol was not detected by the EBT under any condition. Impairment was not indicated by the SFST. Some subjective effects were reported, but few statistically significant differences between conditions were indicated. A wait period prior to ethanol breath testing is not always mandated, depending on jurisdiction, or observed in all applications, such as workplace testing. The results demonstrate that a wait period must be employed to prevent vaping-related false-positive breath ethanol results.

Year:

2023

Year:

2023

Duloxetine, known by its brand name, CymbaltaTM, is a selective serotonin and norepinephrine reuptake inhibitor used to treat major depressive disorders. Determination of patient compliance for duloxetine is typically determined through medication possession ratio (MPR) or plasma concentrations. The purpose of this paper was to characterize normal urinary duloxetine concentrations in patients prescribed duloxetine to monitor patient adherence. Patient data collected from routine screens for duloxetine concentrations in urine were included in this study. Inclusion criteria consisted of patients who were prescribed duloxetine and (i) tested positive for duloxetine, (ii) tested negative for illicit substances and (iii) included creatinine, age and duloxetine dose administered. Of the 5,592 patient urines screened, 2,004 of the results fit into the inclusion criteria. Positive urine concentrations of duloxetine ranged from 50 to 2,722 ng/mL. Duloxetine urine concentrations were normalized to creatinine and dose further characterized by sex, age, body mass index (BMI) and dose in milligrams. Sample distribution included urines collected from 1,487 females and 517 males. The age range of the specimen donors was between 15 and 90 years old with an average age of 52. BMI levels ranged from 13.9 (underweight) to 88.1 (obese), with the average BMI being 33.5. The most common dose of duloxetine prescribed was a daily, oral dose of 60 mg. Analysis of the normalized, transformed creatinine concentrations showed that there was a significant statistical difference (P < 0.05) in the urinary duloxetine concentrations by sex and by dose (mg). Female patients further showed a statistical difference in urinary duloxetine concentration in age groups 18–64 and 64 and older. By characterizing urinary duloxetine concentrations in patients prescribed the medication, normalized distributions of data ranges have been established. These data ranges for urinary duloxetine concentrations can be used to determine patient compliance with duloxetine in routine, clinical samples.

Year:

2022

Year:

2022

Year:

2022

Year:

2022

Year:

2021

Year:

2021

Year:

2020

Collaborators (7)

Carl E Wolf

Virginia Commonwealth University

UNITED STATES
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Matthew S Halquist

Virginia Commonwealth University

UNITED STATES
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Adam Pearcy

Research Assistant Professor

Virginia Commonwealth University

UNITED STATES
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Michelle R Peace

Virginia Commonwealth University

UNITED STATES
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Joseph Turner

Service Professor

Virginia Commonwealth University

UNITED STATES
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Caroline Cobb

Associate Professor

Virginia Commonwealth University

UNITED STATES
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Karen D. Hendricks-Muñoz

University of Virginia School of Medicine

UNITED STATES
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