Acute Opioid Overdose (v1.1)
Research type
Research Study
Full title
Acute Opioid Overdose: Improving understanding through a Phase IV Physiological Study
IRAS ID
172751
Contact name
John Strang
Contact email
Sponsor organisation
King's College London
Eudract number
2016-001877-34
Duration of Study in the UK
0 years, 9 months, 0 days
Research summary
In the last year, 1,194 deaths were attributed to opioid overdose, a 64% increase in the last two years (ONS, 2015). In the UK, opioid overdose is the cause of nearly half of all deaths among injecting users, exceeding blood borne viruses (HIV, hepatitis C) and other diseases associated with injecting drug use (Hickman et al., 2003). In Europe (EMCDDA, 2011) and globally (Degenhardt et al., 2011; UNODC/WHO, 2013), opioid overdose is still one of the leading causes of death among drug users, and represents a significant public health problem.
Opioid overdose can lead to respiratory depression and extremely low blood oxygen (hypoxaemia), and these effects are thought to be triggered by opioid purity. However, this has not been analysed under rigid testing conditions before.
Patients on diamorphine (medical heroin) maintenance with a long-term history of injection drug use will be recruited for this study. Across four testing conditions (each lasting a maximum of two hours), the study will assess acute physiological responses to an increase in regular dose of diamorphine (equivalent to an increase in purity).
Participants will be intensively, and continuously, monitored using non-invasive devices: an ear-clip, nasal-clip and surface electrodes. Physiological measurements of electrical activity of the intercostal muscles (to reliably quantify depression of neural respiratory drive), peripheral oxygen saturation (oxygen in blood), ventilatory frequency (breathing rate) and end-tidal and transcutaneous carbon dioxide (to represent levels of carbon dioxide in expired breath and in blood) will be acquired. Testing sessions will be conducted at the Clinical Research Facility in King’s College Hospital.
The study will address whether the dose of heroin genuinely potentiates overdose by accurately capturing realistic heroin-using scenarios in a laboratory setting.
Summary of study results:
Four male participants (aged 59-72) with a total of 13 dosing sessions across all participants. Respiratory depression measures of pulse oximetry, end-tidal carbon dioxide, transcutaneous carbon dioxide and Neural Respiratory Drive Index did not differ significantly between doses. This was both at peak and lowest points post-diamorphine administration and % change from baseline to peak or lowest points. Pupil size was significantly lower in the 110% and 120% dose sessions compared to the usual 100% dose. However, none of the subjective drug responses showed a significant difference between doses. There were no serious adverse events and participants tolerated the unusual method of administering diamorphine.
REC name
London - South East Research Ethics Committee
REC reference
16/LO/1765
Date of REC Opinion
25 Nov 2016
REC opinion
Further Information Favourable Opinion