Drugs used during the COVID-19 first wave in Vitoria-Gasteiz (Spain) and their presence in the environment

The city of Vitoria-Gasteiz was one of the probable first entrances of the SARS-CoV2 in Spain, one of the worst affected countries in the world during the first COVID 19 wave. Driven by the urgency of the situation, multiple drugs with antiviral activity were used off label. Sadly, most of these treatments were of little or no benefit and thus, the number of patients suffering from COVID-19 attended in intensive care units (ICUs) multiplied. After being administered to patients, a variable proportion of these drugs reach the environment where they may have detrimental effects, although this aspect is usually ignored by healthcare professionals. In this study we measured the patterns of hospital drug use in the city of Vitoria-Gasteiz (Spain) during the first COVID-19 wave pandemic, focusing on those with antiviral activity and those used in the ICUs. Subsequently, we measured concentrations of selected drugs in the city's wastewater treatment plant influent and effluent and estimated the potential risk for the environment. The hospital use of certain antivirals and drugs used for sedo-analgesia were dramatically increased during the first wave (cisatracurium was multiplied by 25 and lopinavir/ritonavir by 20). A mean of 1.632 daily defined doses of hydroxychloroquine were used during the period of February–May 2020. In this study we report the first positive detection of hydroxychloroquine ever in the environment. We also show the second positive report of lopinavir. Low risk was estimated for hydroxychloroquine, lopinavir and ritonavir (Risk quotients (RQ) <1), and medium risk for azithromycin (RQ 0f 0.146).