The T-value in the score for hazard refers to acute toxicity. Underlying data for P, B and T are from Fass. Risk see the report Goodpoint 2019.
Fass environmental information for Allegra (fexofenadine) from Sanofi AB (downloaded 2019-11-27).
Persistence: "Test showed 0% degradation in 28 days (FDA 3.11/OECD 301). Fexofenadin fails to pass the criteria for ready biodegradability which justifies the phrase “Fexofenadin is potentially persistent”."
Bioaccumulation: Log Kow = 0.3 at pH 7 (Test method 1552B).
Toxicity: There are data for 3 trophic levels, most sensitive algae (Desmodesmus subspicatus) EC50 > 200 000 microg/L. Comment: Values reported as greater than are not according to the guidelines. The actual value may be lower.
PEC/PNEC is based on sales data in Sweden in year 2015. PEC/PNEC = 0.0006 which gives the risk insignificant.
Fexofenadine has been found in purified wastewater and surface water within Region Stockholm during 2018.
Comparative assessment of environmental risk when using the antihistamines desloratadine, cetirizine, loratadine, ebastine, clemastine and fexofenadine from a Swedish perspective (Report Goodpoint 2019).
Summary assessment based on (expected) water exposure in relation to toxicity and interaction with targets. Use of clemastine (Tavegyl) is considered to pose a risk of impact on aquatic organisms. It is supported by the fact that measured concentrations in the environment are in good agreement with predicted levels, these levels, although very low, are considered to be able to accumulate in fish to therapeutic concentrations given its high fat solubility (for which there is a reasonable consensus assessment), and finally have levels above Cmax been detected in wild fish. Studies on effects on aquatic organisms are lacking for clemastine, so the assessment is based entirely on the above. Thus, what kind of pharmacological effect can be expected from clemastine through its effect on the histamine receptors, and how severe these are, has not been investigated. The risk of impact is significantly lower, but not negligible, for fexofenadine. The other studied antihistamines pose a low risk based on expected exposure and the likelihood of accumulation in biota to near therapeutic concentrations, at the same time the assessment is uncertain due to insufficient efficacy data. An exchange of clemastine with one of the other studied antihistamines is recommended from an environmental point of view.
Author: Health and Medical Care Administration, Region Stockholm