Presentations to the emergency department with non-medical use of benzodiazepines and Z-drugs: profiling and relation to sales data

C . Lyphout, C. Yates, Z. R. Margolin, P. I. Dargan, A. M. Dines, F. Heyerdahl, K. E. Hovda, I. Giraudon, B. Bucher-Bartelson, J. L. Green, Euro-DEN Research Group, D. M. Wood

Non-medical use of benzodiazepines and Z-drugs is common; however, there is limited information available on the extent of harm related to this in Europe, as well as the relationship between misuse and availability. To describe presentations to the emergency department in Europe related to the recreational use of benzodiazepines and Z-drugs and compare regional differences in these presentations with legal drug sales of benzodiazepines and Z-drugs within each country. Emergency department presentations with recreational misuse of benzodiazepines and Z-drugs were obtained from the Euro-DEN dataset for the period from October 2013 to September 2015; data extracted included demographics, clinical features, reported coused drugs, and outcome data. Sales figures obtained by QuintilesIMS™ (Atlanta, Georgia) were used to compare regional differences in the proportion of benzodiazepines and Z-drugs in the emergency department presentations and legal drug sales across Europe. Over the 2 years, there were 2119 presentations to the Euro-DEN project associated with recreational use of benzodiazepines and/or Z-drugs (19.3% of all Euro-DEN presentations). Presentations with 25 different benzodiazepines and Z-drugs were registered in all countries, most (1809/2340 registered benzodiazepines and Z-drugs, 77.3%) of which were prescription drugs. In 24.9%, the benzodiazepine was not specified. Where the benzodiazepine/Z-drug was known, the most frequently used benzodiazepines and Z-drugs were respectively clonazepam (29.5% of presentations), diazepam (19.9%), alprazolam (11.7%), and zopiclone (9.4%). The proportions of types of benzodiazepines/Z-drugs related to ED-presentations varied between countries. There was a moderate (Spain, UK, Switzerland) to high (France, Ireland, Norway) positive correlation between ED presentations and sales data (Spearman Row's correlation 0.66-0.80, p < 0.005), with higher correlation in countries with higher ED presentation rates. Presentations to the emergency department associated with the non-medical use of benzodiazepines and/or Z-drugs are common, with variation in the benzodiazepines and/or Z-drugs between countries. There was a moderate to high correlation with sales data, with higher correlation in countries with higher ED presentation rates. However, this is not the only explanation for the variation in non-medical use and in the harm associated with the non-medical use of benzodiazepines/Z-drugs.