Scientists from Maastricht University (UM) and RIVM, among others, have for the first time systematically investigated which psychopharmaceuticals are found in surface water in the Netherlands. In particular, the concentrations of the drugs oxazepam and carbamazepine appear to be so high that risks to aquatic life cannot be ruled out.
The study also shows that these substances mainly come from households and not so much from hospitals. The researchers therefore advocate greater awareness among doctors and practitioners who prescribe these drugs.
Surface water
Until now, not much was known about which psychotropic drugs occur in Dutch surface water. To gain more insight into this, the scientists combined data from the so-called Water Quality Portal with data from the Medicines and Aids Information Project of the National Health Care Institute.
Not all psychopharmaceuticals used are measured by the water boards. It is also not known for all products what their effect is on the aquatic environment. To identify the main sources of psychotropic drugs in the surface water, the researchers used detailed data from a water treatment plant in Winterswijk.
“Our measurements show that substances such as carbamazepine, oxazepam and fluoxetine are regularly found in surface water,” says researcher Caroline Moermond of RIVM. “The main source for this is the use by patients at home. Sewage treatment plants can only remove part of this. For this reason, carbamazepine and oxazepam pose a risk to aquatic organisms such as fish and small crustaceans in some places. Psychopharmaceuticals influence the behavior of these organisms, making them more aggressive or, conversely, more passive. This can ultimately have an effect on several food chains.”
Psychopharmaceuticals
Antidepressants, antipsychotics, sleeping pills, tranquilizers and other psychotropic drugs are increasingly prescribed worldwide.
Oxazepam, the substance that has regularly been found in Dutch surface water, has been one of the most prescribed medicines in our country for many years. It helps to reduce feelings of anxiety and tension, but is also widely used for stress or burnout complaints.
Carbamazepine is a drug that suppresses the symptoms of epilepsy and is also regularly prescribed for the treatment of patients with bipolar disorder.
UM researcher and psychiatrist Jurjen Luykx believes that doctors should be much more alert to the amount of medicines they prescribe. “But how we prescribe medication also deserves attention. This concerns, for example, the question of whether and how quickly we can start phasing out. We also need to advise patients more often on how best to deal with leftover medication, to prevent it from being flushed down the toilet. In addition, we can use the results of this study to investigate in which cases other drugs that work as well as oxazepam and carbamazepine could be given priority in treatment guidelines. It would be good if such guidelines take more account of the impact of treatments on the environment and climate in the future.”