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Refining the excretion factors of methadone and codeine for wastewater analysis - Combining data from pharmacokinetic and wastewater studies


Thai, PK and Lai, FY and Bruno, R and van Dyken, E and Hall, W and O'Brien, J and Prichard, J and Mueller, JF, Refining the excretion factors of methadone and codeine for wastewater analysis - Combining data from pharmacokinetic and wastewater studies, Environment International, 94 pp. 307-314. ISSN 0160-4120 (2016) [Refereed Article]

Copyright Statement

Copyright 2016 Elsevier Ltd.

DOI: doi:10.1016/j.envint.2016.05.033


Analysing drug residues in wastewater (wastewater analysis) to monitor the consumption of those drugs in the population has become a complementary method to epidemiological surveys. In this method, the excretion factor of a drug (or the percentage of drug metabolites excreted through urine) is a critical parameter for the back-estimation of the consumption of a drug. However, this parameter is usually derived from a small database of human pharmacokinetic studies. This is true for methadone and codeine, the two most commonly used opioids and also common substances of abuse. Therefore, we aimed to refine the current excretion factors used for estimating methadone and codeine by analysing published data from the literature on the excretion of methadone, its main metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and codeine. Our review included both human drug pharmacokinetic studies and wastewater analysis studies. We found that while the commonly used excretion factor of methadone (~27.5%) was relatively accurate, the excretion factor of EDDP, a better biomarker for methadone consumption in sewer epidemiology, should be twice that of methadone (i.e. 55%) instead of the current equal or half values. For codeine, the excretion factor should be ~30% instead of 63.5% or 10% as previously used in wastewater analysis studies. Data from wastewater analysis studies could be used in this way to refine the excretion factors of the drugs of interest

Item Details

Item Type:Refereed Article
Keywords:drug use, wastewater epidemiology, sewer epidemiology, EDDP, drug abuse, misuse, opioids
Research Division:Psychology
Research Group:Other psychology
Research Field:Other psychology not elsewhere classified
Objective Division:Health
Objective Group:Public health (excl. specific population health)
Objective Field:Public health (excl. specific population health) not elsewhere classified
UTAS Author:Bruno, R (Associate Professor Raimondo Bruno)
UTAS Author:van Dyken, E (Miss Emma van Dyken)
UTAS Author:Prichard, J (Associate Professor Jeremy Prichard)
ID Code:112890
Year Published:2016
Funding Support:Australian Research Council (LP150100364)
Web of Science® Times Cited:39
Deposited By:Psychology
Deposited On:2016-12-02
Last Modified:2018-03-23

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