New framework to diagnose the direct disposal of prescribed drugs in wastewater: a case study of the antidepressant fluoxetine.

Petrie, Bruce; Youdan, Jane; Barden, Ruth; Kasprzyk-Hordern, Barbara

Abstract

Intentional or accidental release (direct disposal) of high loads of unused pharmaceuticals into wastewater can go unnoticed. Here, direct disposal of a pharmaceutical drug via the sewer network was identified for the first time using wastewater analysis. An irregularly high load of the antidepressant fluoxetine in raw wastewater (10.5 ± 2.4 g d–1) was up to 11 times greater than any other day. National prescription data revealed a predicted daily fluoxetine load for the studied treatment works to be 0.4–1.6 g d–1. Enantio-selective analysis showed the high load of fluoxetine was present as a racemic mixture, which is typical for fluoxetine in dispensed formulations. As fluoxetine undergoes stereoselective metabolism within the body, a racemic mixture in wastewater suggests a nonconsumed drug was the major contributor of the high load. This was confirmed by its major metabolite norfluoxetine whose load did not increase on this day. Considering the most commonly prescribed formulation of fluoxetine, this increased load accounts for the disposal of ~915 capsules. Furthermore, as fluoxetine is prescribed as one capsule per day, disposal is unlikely to be at the patient level. It is postulated that direct disposal was from a facility which handles larger quantities of the drug (e.g., a pharmacy).

Citation

PETRIE, B., YOUDAN, J., BARDEN, R., KASPRZYK-HORDERN, B. 2016. New framework to diagnose the direct disposal of prescribed drugs in wastewater: a case study of the antidepressant fluoxetine. Environmental science and technology [online], 50(7), pages 3781-3789. Available from: https://doi.org/10.1021/acs.est.6b00291

• Journal Article Type: Article
• Acceptance Date: Mar 14, 2016
• Online Publication Date: Mar 24, 2016
• Publication Date: Apr 5, 2016
• Deposit Date: Mar 5, 2020
• Publicly Available Date: Mar 5, 2020
• Journal: Environmental science and technology
• Print ISSN: 0013-936X
• Electronic ISSN: 1520-5851
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 50
• Issue: 7
• Pages: 3781-3789
• DOI: https://doi.org/10.1021/acs.est.6b00291
• Keywords: Metabolism; Wastewater; Pharmaceuticals; Computer simulations; Water treatment
• Public URL: https://rgu-repository.worktribe.com/output/842913