The toxicity is not tested on blue-green algae (cyanobacteria) , thats why environmental risk can not be significantly calculated. When selecting the algal test for antibiotics the European Medicines Agency, EMA recommends test on blue-green algae (cyanobacteria).
The risk classification is based on total sold amount (kg) of the substance in Sweden during the year 2015 and EC50 72 h (growth inhibition) för green algae = 7. 4 mg/L.
Levofloxacin is the S-enantiomer of the racemate ofloxacin. Therefore see also see information about ofloxacin. In analyzes of ofloxacin in water both ofloxacin and levofloxacin are measured.
Ofloxacin has been detected in treated wastewater and drinking water in Stockholm County. Ofloxacin was included in the Stockholm County Council's table of pharmaceuticals with a negative environmental impact within Stockholm County, according to the environmental programme, Environmental Challenge 2016, but the sale has decreased in the county and also the concentration in the waste water. Now ofloxacin has been deleted from the table of substances with environmental risk. The concentrations in the water will continue to be monitored by the SLL's Sustainability Department.
Studies have shown that even low concentrations of antibiotics in the environment may trigger antibiotic resistance and should therefore be taken to ensure that as little as possible end up in our environment.
Author: The Pharmaceutical unit of Region Stockholm