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Differentiating new cannabis use from residual urinary cannabinoid excretion in chronic, daily cannabis users.

Abstract

AIMS

To develop and validate empirically a mathematical model for identifying new cannabis use in chronic, daily cannabis smokers.

DESIGN

Models were based on urinary creatinine-normalized (CN) cannabinoid excretion in chronic cannabis smokers.

SETTING

For model development, participants resided on a secure research unit for 30 days. For model validation, participants were abstinent with daily observed urine specimens for 28 days.

PARTICIPANTS

A total of 48 (model development) and 67 (model validation) daily cannabis smokers were recruited.

MEASUREMENTS

All voided urine was collected and analyzed for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) by gas chromatography-mass spectrometry (GCMS; limit of quantification 2.5 ng/ml) and creatinine (mg/ml). Urine THCCOOH was normalized to creatinine, yielding ng/mg CN-THCCOOH concentrations. Urine concentration ratios were determined from 123,513 specimen pairs collected 2-30 days apart.

FINDINGS

A mono-exponential model (with two parameters, initial urine specimen CN-THCCOOH concentration and time between specimens), based on the Marquardt-Levenberg algorithm, provided a reasonable data fit. Prediction intervals with varying probability levels (80, 90, 95, 99%) provide upper ratio limits for each urine specimen pair. Ratios above these limits suggest cannabis re-use. Disproportionate numbers of ratios were higher than expected for some participants, prompting development of two additional rules that avoid misidentification of re-use in participants with unusual CN-THCCOOH excretion patterns.

CONCLUSIONS

For the first time, a validated model is available to aid in the differentiation of new cannabis use from residual creatinine-normalized 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (CN-THCCOOH) excretion in chronic, daily cannabis users. These models are valuable for clinicians, toxicologists and drug treatment staff and work-place, military and criminal justice drug-testing programs.

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  • Authors+Show Affiliations

    ,

    Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Biomedical Research Center, Baltimore, MD 21146, USA.

    , , , , , ,

    Source

    Addiction (Abingdon, England) 106:3 2011 Mar pg 499-506

    MeSH

    Adult
    Algorithms
    Chronic Disease
    Creatinine
    Diagnosis, Differential
    Dronabinol
    Drug Residues
    Female
    Gas Chromatography-Mass Spectrometry
    Humans
    Male
    Marijuana Abuse
    Models, Biological
    Nonlinear Dynamics
    Predictive Value of Tests
    Psychotropic Drugs
    Recurrence
    Substance Abuse Detection
    Time Factors
    Young Adult

    Pub Type(s)

    Journal Article
    Research Support, N.I.H., Extramural
    Research Support, N.I.H., Intramural
    Validation Studies

    Language

    eng

    PubMed ID

    21134021

    Citation

    Schwilke, Eugene W., et al. "Differentiating New Cannabis Use From Residual Urinary Cannabinoid Excretion in Chronic, Daily Cannabis Users." Addiction (Abingdon, England), vol. 106, no. 3, 2011, pp. 499-506.
    Schwilke EW, Gullberg RG, Darwin WD, et al. Differentiating new cannabis use from residual urinary cannabinoid excretion in chronic, daily cannabis users. Addiction. 2011;106(3):499-506.
    Schwilke, E. W., Gullberg, R. G., Darwin, W. D., Chiang, C. N., Cadet, J. L., Gorelick, D. A., ... Huestis, M. A. (2011). Differentiating new cannabis use from residual urinary cannabinoid excretion in chronic, daily cannabis users. Addiction (Abingdon, England), 106(3), pp. 499-506. doi:10.1111/j.1360-0443.2010.03228.x.
    Schwilke EW, et al. Differentiating New Cannabis Use From Residual Urinary Cannabinoid Excretion in Chronic, Daily Cannabis Users. Addiction. 2011;106(3):499-506. PubMed PMID: 21134021.
    * Article titles in AMA citation format should be in sentence-case
    TY - JOUR T1 - Differentiating new cannabis use from residual urinary cannabinoid excretion in chronic, daily cannabis users. AU - Schwilke,Eugene W, AU - Gullberg,Rod G, AU - Darwin,William D, AU - Chiang,C Nora, AU - Cadet,Jean Lud, AU - Gorelick,David A, AU - Pope,Harrison G, AU - Huestis,Marilyn A, Y1 - 2010/12/06/ PY - 2010/12/8/entrez PY - 2010/12/8/pubmed PY - 2011/5/26/medline SP - 499 EP - 506 JF - Addiction (Abingdon, England) JO - Addiction VL - 106 IS - 3 N2 - AIMS: To develop and validate empirically a mathematical model for identifying new cannabis use in chronic, daily cannabis smokers. DESIGN: Models were based on urinary creatinine-normalized (CN) cannabinoid excretion in chronic cannabis smokers. SETTING: For model development, participants resided on a secure research unit for 30 days. For model validation, participants were abstinent with daily observed urine specimens for 28 days. PARTICIPANTS: A total of 48 (model development) and 67 (model validation) daily cannabis smokers were recruited. MEASUREMENTS: All voided urine was collected and analyzed for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) by gas chromatography-mass spectrometry (GCMS; limit of quantification 2.5 ng/ml) and creatinine (mg/ml). Urine THCCOOH was normalized to creatinine, yielding ng/mg CN-THCCOOH concentrations. Urine concentration ratios were determined from 123,513 specimen pairs collected 2-30 days apart. FINDINGS: A mono-exponential model (with two parameters, initial urine specimen CN-THCCOOH concentration and time between specimens), based on the Marquardt-Levenberg algorithm, provided a reasonable data fit. Prediction intervals with varying probability levels (80, 90, 95, 99%) provide upper ratio limits for each urine specimen pair. Ratios above these limits suggest cannabis re-use. Disproportionate numbers of ratios were higher than expected for some participants, prompting development of two additional rules that avoid misidentification of re-use in participants with unusual CN-THCCOOH excretion patterns. CONCLUSIONS: For the first time, a validated model is available to aid in the differentiation of new cannabis use from residual creatinine-normalized 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (CN-THCCOOH) excretion in chronic, daily cannabis users. These models are valuable for clinicians, toxicologists and drug treatment staff and work-place, military and criminal justice drug-testing programs. SN - 1360-0443 UR - https://www.unboundmedicine.com/medline/citation/21134021/abstract/Differentiating_new_cannabis_use_from_residual_urinary_cannabinoid_excretion_in_chronic_daily_cannabis_users_ L2 - https://doi.org/10.1111/j.1360-0443.2010.03228.x DB - PRIME DP - Unbound Medicine ER -