Stability and uptake of methylphenidate and ritalinic acid in nine-spine stickleback (Pungitius pungitius) and water louse (Asellus aquaticus)

Erin S Mccallum,Tomas Brodin,Richard H Lindberg,Patrik L Andersson

doi:10.1007/s11356-019-04557-9

Abstract

The presence of human pharmaceuticals in the environment has garnered significant research attention because these compounds may exert therapeutic effects on exposed wildlife. Yet, for many compounds, there is still little research documenting their stability in the water column and uptake in organism tissues. Here, we measured the uptake and stability of methylphenidate (Ritalin®, a frequently prescribed central nervous system stimulant) and its primary metabolite, ritalinic acid, in (1) water only or (2) with nine-spine stickleback and water louse. Methylphenidate degraded to ritalinic acid in both studies faster at a higher temperature (20 °C versus 10 °C), with concentrations of ritalinic acid surpassing methylphenidate after 48–100 h, depending on temperature. The concentration of methylphenidate in stickleback was highest at the first sampling point (60 min), while the concentration in water louse tissues reached comparatively higher levels and peaked after ~ 6 days. Neither stickleback nor water louse took up ritalinic acid in tissues despite being present in the water column. Our findings provide valuable data for use in future risk assessment of methylphenidate and will aid in the design of studies aimed at measuring any ecotoxicological effects on, for example, the behaviour or physiology of aquatic organisms.

Highlights

IntroductionOne such compound with the potential to modulate behaviour is methylphenidate (e.g., Ritalin®, Concerta®): a central nervous system stimulant prescribed to promote executive functions such as attention and focus in humans
The presence of pharmaceuticals in the environment has drawn widespread concern from researchers and environmental managers over the impacts that exposure to Responsible editor: Philippe Garrigues Electronic supplementary material The online version of this article contains supplementary material, which is available to authorized users.One such compound with the potential to modulate behaviour is methylphenidate (e.g., Ritalin®, Concerta®): a central nervous system stimulant prescribed to promote executive functions such as attention and focus in humans
Methylphenidate degraded to ritalinic acid and faster at 20 °C than at 10 °C; likewise, ritalinic acid formed faster at 20 °C than at 10 °C (Table 1; Fig. 1b)

Summary

Introduction

One such compound with the potential to modulate behaviour is methylphenidate (e.g., Ritalin®, Concerta®): a central nervous system stimulant prescribed to promote executive functions such as attention and focus in humans. Reductions in anxiety behaviours have been noted in adult guppies (Poecilia reticulata) exposed to 250 ng/L (De Serrano et al 2016) and in zebrafish exposed to a much higher concentration (50 mg/ L) as embryos (Levin et al 2011)

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Results

Conclusion