Using community prescribed data to predict emerging pollutants

Introduction: As the world wide population increases more demand is put on resources such as waste water treatment and drinking water supply. In our modern times most people will take medicines at some point in their lives and most of these medicines find their way into the waste water system by excretion. With changing disease profile, more people being treated at home and new medicines coming on to the market, the profile of pharmaceuticals present in waste water may slowly but continually shift. It is therefore important to review pharmaceutical use, to ensure there is an up to date profile of which drugs are cause for concern both now and in the future. The aim of this work is to review the drug prescribing pattern over a number of years, for drugs which are already of environmental concern and also drugs which may become harmful to the environment due to a changing or increasing pattern in prescribing. This will inform which substances require further investigation in the environment.
Methods: Using community prescription drug data in Scotland (2009-2014), (Information Services Scotland, 2010), initially the top 10 prescribed drugs were identified. This data showed that omeprazole has overtaken aspirin as the most prescribed drug. However the dose for each drug can vary therefore load (kg/annum) was calculated. A short-list of drugs was selected for further consideration (Table 1). Metabolic pathways, breakdown mechanisms and excretion rates were also taken into consideration to determine whether metabolites and breakdown products should also be investigated in the environment.