No measurements of alimemazine, in wastewater or the external environment, have been reported either in Sweden or abroad. Effect studies of alimemazine are very insufficient. Alimemazine is potentially persistent.
In the literature there are contradictory fat solubility data for alimemazine reported. However, several independent sources report an estimated fat solubility (log Pow) above 4, indicating that the substance has a high potential for bioaccumulation.
Use of oxazepam has been estimated to pose a risk to environmental impact based on measured concentrations in Swedish surface water and in Swedish wild fish. These concentrations are very close to those affecting fish behavior. Diazepam is metabolised to some extent to oxazepam and may therefore contribute to this risk. Diazepam and oxazepam are therefore included in the Stockholm County Council's table of pharmaceuticals with risk for negative environmental impact according to the environmental program 2017-2021.
Alimemazine has not been studied in the environment, relevant efficacy studies are lacking and there are contradictory fat solubility data for alimemazine. However, the limited data available suggests that effects in the environment of alimemazine are fully possible, but further investigation of alimemazine fat solubility should be done.
The risk assessment can not be excluded, according to Fass.se, is due to toxicity studies being incomplete, why a risk calculation has not been possible. It is voluntary for manufacturers to provide information on the environmental impact.
Author: The Pharmaceutical unit of Region Stockholm