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Record W4414740878 · doi:10.1093/clinchem/hvaf086.677

B-290 A perspective on commonly used drugs in patients receiving treatment for opioid use disorder in Ontario, Canada

2025· article· en· W4414740878 on OpenAlexaffabout
Josko Ivica, Jacqueline Hudson, Matthew Nichols, Eleonora Petryayeva, Joseph Macri, Alannah McEvoy, M. Constantine Samaan

Bibliographic record

VenueClinical Chemistry · 2025
Typearticle
Languageen
FieldMedicine
TopicOpioid Use Disorder Treatment
Canadian institutionsQueen's UniversityManitoba HealthLondon Health Sciences CentreMcMaster UniversityHamilton Health Sciences
Fundersnot available
KeywordsBuprenorphineOpioid use disorderMethadoneOpiate Substitution TreatmentDemographicsOpioidDrugPerspective (graphical)

Abstract

fetched live from OpenAlex

Abstract Background Urine drug screens (UDS) are limited to a few drug classes of interest and are typically done by immunoassay-based (IA) methods. Screening results can then be confirmed by liquid chromatography coupled with tandem mass spectrometry methods (LC-MS/MS) if required. Medication-assisted treatment (MAT) has been used for treatment and monitoring of Opioid Use Disorders (OUD). Medications used in MAT are usually methadone and/or a combination of buprenorphine and naloxone. The aim of this is study was to see what other drugs the participants from the Pharmacogenetics of Opioid Substitution Treatment Response (POST) study in Ontario, Canada, were taking in addition to the prescribed medications. Methods Two hundred POST study participants provided their urine samples to be tested on LC-MS/MS after their urines had been screened by IA. There were 99 drugs tested in this method. The kits were provided by Chromsystems (Grafelfing, Germany) and we followed their procedure for the analysis of these drugs. We investigated the participants’ demographics by age and gender/sex, the most commonly used drugs, their most common combinations, and the number of participants who were taking = 2 drugs, confirmed by LC-MS/MS. We also checked discordances between IA and LC-MS/MS for MATs, and amphetamine and methamphetamine. All the analyses and pertaining graphs were done in Microsoft Excel (Microsoft Corporation). Results The average age for all participants was 39.5 years. The participants were divided into 5 age groups (20-29.9, 30-30.9, 40-49.9, 50-50.9, = 60) and two sexes (males and cis/trans-females). Majority (n=161, 80.5%) of the participants were of the European descent, and 43.0 % were females. The three most commonly abused drugs were selected for a more detailed demographics analysis: THC-COOH (n=96, 48%), amphetamine and methamphetamine (n=47, 23.5%, for both). THC-COOH was present in 11.5% participants aged 20-29.9, 16.5% aged 30-39.9, 10% aged 40-49.9, 8% aged 50-59.9 and 2% = 60 years of age. THC-COOH was present in 31.5% males and 16% females (0.5% trans-females). Both amphetamine and methamphetamine were present in 23.5% of the participants (n=47), and both were present in 15% males and 8.5% females, as expected. There was only a slight difference between age groups. The percentage of the most common drug combination was as follows: amphetamine and methamphetamine (42%); amphetamine, methamphetamine combined with THC-COOH (19%); and amphetamine, methamphetamine combined with norfentanyl (18%). The greatest number of participants who took = 2 drugs confirmed by LC-MS/MS (n=40, 20%) had 3 drugs in urine. Surprisingly, 26.5% of participants who were compliant with their MATs, confirmed by LC-MS/MS, were negative on IA screens. Thirty-one participants (15.5%) were falsely positive for either amphetamine or methamphetamine on IA, after being confirmed negative on LC-MS/MS. Conclusion This work has shed important light into what populations across Ontario, who are receiving MAT for OUD, concurrently use in addition to their prescribed treatment. It confirmed the importance of LC-MS/MS for confirmation of the compliance with MAT, as well as confirmation of commonly taken illicit drugs.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.001
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.143
Threshold uncertainty score0.998

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.001
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.026
GPT teacher head0.335
Teacher spread0.309 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

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Citations0
Published2025
Admission routes2
Has abstractyes

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