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

Background: 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.

Aim: 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.

Methods: 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.

Results: 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.

Conclusion: 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.