[Environmental Impact of Pharmaceuticals - How can doctors lead sustainable prescribing practices?]

Medicines are the most common and, in many cases, the most effective treatment for disease. Medicine use is expected to continue to rise in the coming years, due in part to an ageing population. At the same time, knowledge of the environmental impact of pharmaceuticals has grown. *Therefore*, there is increasing discussion of the need for clinicians to take such impacts into account when selecting treatment for their patients. The World Health Organization has proposed the One Health approach, which emphasises the interconnection between human health, animal health and the environment. According to the One Health approach, all of these dimensions must be considered in order to respond effectively to contemporary health threats. Medicines are designed to have specific effects on living organisms, and many of them withstand a wide range of environmental conditions without breaking down or losing activity. Pharmaceuticals can have adverse environmental effects in three ways: through pollution and the carbon footprint associated with their manufacture and distribution; through excretion of unchanged drug or active metabolites into the environment via urine or faeces; or through improper disposal. This article discusses the environmental impact of pharmaceuticals, their potential effects on human health, the current situation in Iceland, and measures to mitigate adverse effects and counter further deterioration.