Recreational drug poisonings reported to six European poison centres increased significantly between 2021 and 2024, although they represented only about 3% of all calls. The total number of cases rose from 5,619 in 2021 to 7,229 in 2024, with the largest increases observed in Austria, Freiburg (Germany), and the United Kingdom. The most frequently implicated drugs were delta-9-tetrahydrocannabinol (THC), cocaine, amfetamine, and MDMA. Rising rates were seen for THC in Austria and Freiburg; cocaine in Freiburg and the UK; amfetamine in Freiburg and Sweden; and ketamine in Austria, Freiburg, and the UK. In 2024, amfetamine poisonings peaked in Freiburg (0.63%) and Sweden (0.94%), cocaine in Freiburg (0.78%) and the UK (0.74%), and ketamine in the Netherlands (0.42%) and the UK (0.24%). Coordinated European monitoring could support timely public health interventions.
Methoxetamine (MXE), a ketamine analogue used as a new psychoactive substance, has multiple neuropharmacological effects. In rat primary cortical cells, 10 µM MXE increased glutamate-evoked calcium influx, while ketamine did not. Both MXE and ketamine inhibited spontaneous neuronal activity, with IC50 values of 0.5 µM and 1.2 µM respectively. In human SH-SY5Y cells, MXE slightly reduced calcium increases triggered by potassium and acetylcholine. In human stem cell-derived neurons, MXE only slightly reduced ATP-evoked calcium increases and inhibited spontaneous activity at higher concentrations. MXE also potently blocked human monoamine transporters, especially the serotonin transporter (SERT, IC50 2 µM), followed by norepinephrine (NET, 20 µM) and dopamine (DAT, 33 µM). These in vitro findings provide initial insight into MXE's mechanisms of action.