11 analytically confirmed cases of mexedrone use among polydrug users

Introduction: Mexedrone, 3-methoxy-2-(methylamino)-1-(4-methylphenyl)propan-1-one, is the alpha-methoxy-derivative of mephedrone (4-methyl-N-methyl cathinone). Mexedrone inhibits the re-uptake of serotonin and dopamine in a dose-dependent manner and has affinity for serotonin and dopamine membrane transporters and receptors (5-HT2 and D2 receptors), producing sympathomimetic effects similar to amfetamines. To date there are no published clinical reports on mexedrone use that are analytically confirmed.

Objective: To characterise the features of mexedrone use in patients who presented to our hospital after using a variety of psychoactive substances including mexedrone, with analytical confirmation in each case.

Methods: This is an observational case series. Urine toxicological screening using ultra-performance liquid chromatography with tandem mass spectrometry and exact mass time of flight was employed in all patients.

Results: A total of 305 cases were screened and mexedrone was identified in 11 urine samples. Agitation was the most common presenting feature in 10 of 11 patients. This was marked to the extent of aggression in some cases, with six patients requiring sedation and/or physical restraint. Delusions and hallucinations, often with paranoia, were observed in three cases with a prominent supernatural/demonic theme. None of these individuals had a history of psychosis. Seven of 11 patients were tachycardic >100 bpm. The median length of stay was 20 hours (range 2-77; IQR 4-33). Mexedrone alone is only likely to have been responsible for these clinical features in 2 cases; in two others mexedrone was found in high concentration along with substantial amounts of other stimulants. In 7 other cases other stimulants detected more likely explained the features. However, comprehensive analytical data enabled us to identify the full complement of agents contributing to the clinical presentation.

Conclusions: Agitation was the predominant clinical feature in this case series and was often accompanied by a sinus tachycardia; mexedrone was primarily responsible in 2 patients but contributed substantially in two others. Patients typically recovered fully within 24 hours, unless they required sedation.