Journal of Medical Toxicology

, Volume 15, Issue 1, pp 4–11 | Cite as

Concurrent Use of Benzodiazepine by Heroin Users—What Are the Prevalence and the Risks Associated with This Pattern of Use?

  • T. Yamamoto
  • P. I. Dargan
  • A. Dines
  • C. Yates
  • F. Heyerdahl
  • K. E. Hovda
  • I. Giraudon
  • R. Sedefov
  • D. M. WoodEmail author
  • On behalf of the Euro-DEN Research Group
Original Article



Polydrug use involving heroin and benzodiazepines is common. The potential risk of additive pharmacological effects may be associated with poorer outcomes in patients who use benzodiazepines together with heroin. The aim of this study was to determine the clinical picture of patients presenting to the emergency department following acute drug toxicity involving heroin and benzodiazepines.


Exposure information, clinical data and outcome of acute drug toxicity presentations were collected between 1 October 2013 and 30 September 2014 as part of the European Drug Emergencies Network (Euro-DEN) project. The database was interrogated to identify patients who had taken heroin with or without benzodiazepine(s).


A total of 1345 presentations involving acute heroin toxicity were identified: 492 had used one or more non-heroin/benzodiazepine drug and were not further considered in this study; 662 were lone heroin users and 191 had co-used heroin with one or more benzodiazepines. Co-users were more likely than lone heroin users to have reduced respiratory rate at presentation 12.7 ± 4.9 vs 13.6 ± 4.4 (p = 0.02) and require admission to hospital 18.3 vs 9.8% (p < 0.01). There were no differences in critical care admission rates 3.1 vs 3.9% (p = 0.83) or length of stay 4 h 59 min vs 5 h 32 min (p = 0.23). The 3 most common benzodiazepines were clonazepam, diazepam, and alprazolam. No differences were observed for clinical features between the three benzodiazepines.


This study shows that co-use of heroin and benzodiazepines is common, although the overall outcomes between co-users of heroin and benzodiazepines and heroin-only users were similar.


Heroin Benzodiazepines Acute toxicity Euro-DEN Emergency department 



 Euro-DEN Research Group Collaborators: Chevillard L, Eyer F, Galicia M, Homar C, Jürgens G, Kabata PM, Liakoni E, Liechti ME, Markey G, Mégarbane B, Miro O, Moughty A, O’ Connor N, Paasma P, Persett PS, Pold K, Puiguriguer J, Shields G, Vallersnes OM, Waring WS, Waldman W, Yeung S-J.

Sources of Funding

This study received a financial support from the DPIP/ISEC Programme of the European Union.

Compliance with Ethical Standards

Ethical approval was obtained by each centre to collect the data as part of Euro-DEN project.

Conflicts of Interest

PID and DMW work with the European Monitoring Centre for Drugs and Drug Addiction and the UK Advisory Council for the Misuse of Drugs. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.


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Copyright information

© American College of Medical Toxicology 2018

Authors and Affiliations

  • T. Yamamoto
    • 1
  • P. I. Dargan
    • 1
    • 2
  • A. Dines
    • 1
  • C. Yates
    • 3
  • F. Heyerdahl
    • 4
  • K. E. Hovda
    • 4
  • I. Giraudon
    • 5
  • R. Sedefov
    • 5
  • D. M. Wood
    • 1
    • 2
    Email author
  • On behalf of the Euro-DEN Research Group
  1. 1.Clinical Toxicology, Guy’s and St Thomas’ NHS Foundation Trust and King’s Health PartnersLondonUK
  2. 2.Faculty of Life Sciences and MedicineKing’s College LondonLondonUK
  3. 3.Emergency Department and Clinical Toxicology UnitHospital Universitari Son EspasesMallorcaSpain
  4. 4.The National CBRNe Centre of Medicine, Department of Acute Medicine, Medical DivisionOslo University HospitalOsloNorway
  5. 5.European Monitoring Centre for Drugs and Drug Addiction (EMCDDA)LisbonPortugal

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