The T-value in the score for hazard refers to chronic toxicity. Underlying data for P, B and T are from Fass.
Fass environmental information for Losartan Comp (hydrochlorothiazide, losartan) (downloaded 2018-03-19).
Persistence: "Losartan has been found to degrade under natural light conditions however no data are available on metabolites. Therefore the phrase “Losartan is potentially persistent” was thus chosen."
Bioaccumulation: Log Kow = 1.2.
Chronic toxicity: There is NOEC for 3 trophic levels, lowest NOEC for fish (Pimephales promelas) 10 000 microg/L.
PPEC/PNEC is based on sales data in Sweden in year 2015. PEC/PNEC = 0.001 which gives the risk insignificant.
Prioritization of pharmaceuticals with environmental risks within SLL. Stockholm: Goodpoint; 2016. Report LS 2016-0634. Fairly large margin between levels in the environment and the amount of environmental impact. However, environmental impact data are limited.
Pharmaceutical analyses of water in Stockholm County
Losartan has been detected in treated wastewater in Stockholm County (2005–2012).
Relative assessment of environmental risk when using angiotensin II antagonists irbesartan and losartan in Sweden (Report Goodpoint 2018). Measurements of irbesartan in incoming and outgoing wastewater in three wastewater treatment plants in Stockholm since 2012 in SLL's internal measurement series, show levels of up to 373 ng/L and, in principle, irbesartan is not reduced in the wastewater treatment plants. Irbesartan is also not microbially readily degradable in laboratory studies.
According to Fass (Aprovel, Sanofi), irbesartan has a log P of 1.13 but Drugbank reports significantly higher predicted log P between 4.5 and 5.56. The fact that irbesartan is found in wild Swedish fish speaks strongly against a log P of 1.13.
Author: The Pharmaceutical unit of Region Stockholm