LAUSR

Pharmaceutical waste is an important and growing environmental concern. Many drugs have been detected in significant concentrations in waterways, and they are likely to be particularly harmful when “constantly introduced to aquatic ecosystems,” such as drugs inappropriately discarded on a daily basis. Environmental contamination with pharmaceuticals has consequences for wildlife and fragile ecosystems, and unquantified risks to human health due to exposure via food and water. Anaesthetists carefully titrate medication doses for individual patients based on observed clinical effects. Unused medication from standardised ampoule volumes require disposal. These discarded unused drug solutions represent an inefficient (and thus low value) use of resources, contributing to unnecessary financial and environmental costs from pharmaceutical production and the supply chain. Pharmaceuticals account for 19% of total carbon emissions from Australia’s healthcare system, with healthcare representing 7% of national emissions. Wastewater contamination from pharmaceutical manufacturing is also well-documented and is likely to increase with greater procurement volumes necessitated by drug wastage. Propofol has received considerable attention as a potentially more environmentally friendly drug for maintenance of general anaesthesia. The life cycle greenhouse gas emissions associated with propofol total intravenous anaesthesia (TIVA) are several orders of magnitude lower than with inhalational anaesthetic agents. However, propofol itself is an environmental hazard. It accumulates in fats, is toxic to aquatic life, and is not readily biodegradable. In the human body, propofol is extensively metabolised, with <1% excreted unchanged, however, it requires incineration to be destroyed ex vivo. While the true extent and nature of its biotoxicity remains uncertain, it is considered overall to have ‘low’ environmental risk. In anaesthesia, propofol is one of the most common drugs that is prepared in syringes in volumes that are incompletely utilised for a given patient. Observedwastage ranges from 32%–50%, accounting for 45% of total operating theatre drug waste in one study. Other propofol life cycle considerations, including sourcing and transport of constituents (e.g. soybean oil) and single-use plastics (syringes, infusion tubing, processed electroencephalogram monitors, etc.), also contribute to the environmental impact and healthcare costs. In Australia, the Environment Protection Authority requires pharmaceutical waste to be incinerated for the protection of human and environmental health. Further regulation of pharmaceutical waste is state/territory specific. In Victoria, the relevant legal frameworks are the Drugs, Poisons and Controlled Substances Act 1981 and Drugs, Poisons and Controlled Substances Regulations 2017. These require that Schedule 8 (S8) medicines and Schedule 4 Drugs of Dependence be destroyed by an authorised health practitioner and witnessed by a second authorised health practitioner. There are exceptions to the witnessing requirement, such as when destroying a vial of previously sterile medicine, however it is still encouraged to reduce risks of diversion. The Victorian Department of Health and Human Services recommends that discarded S8 medications are rendered non-recoverable and non-identifiable, and requires that containers for S8 medicines are considered to be pharmaceutical waste and disposed of in the same manner.