Overdose is common among drug users, in particular among those who use opiates.  The Economic and Social Research Institute was requested to provide data from the Hospital In-Patient Inquiry Scheme (HIPE), in order to ascertain the number of hospital admissions (using discharge data as a proxy) classified as overdoses.  Data were requested on the number (per cent) of cases admitted to an acute hospital with poisoning as a result of opiates, sedatives, hypnotics, stimulants and psychotropic agents by drug-dependency status and recorded on the HIPE between 1996 and 2001. 

The numbers of patients admitted to an acute hospital (discharge data used as a proxy) having overdosed were stable at around 2,500 each year between 1996 and 2001.  Overall, a very small number of cases (49) died during the period under review.  Between two and four per cent of those admitted with an overdose had a history of drug dependence.  The average number of overdoses among those with drug dependency was 93 per year between 1996 and 2000, with a decrease to 59 in 2001.  Of those with a history of drug dependence, 98 per cent were aged between 15 and 64 years, 68 per cent were male, 76 per cent were treated in the Eastern Regional Health Authority area and one-third were treated for a narcotic-related overdose. 

It has been suggested that most deaths from overdose occur in the community.  Between January 1998 and December 2001, the Dublin City and County Coroners investigated 332 opiate-related deaths in Dublin.  Byrne1collated and analysed this data.  Over the four years, over two-thirds (67% 224/342) of those who died were between 15 and 34 years old and the majority (87%) were men.  Fifty-six per cent were alone when they died.  Over half died in their homes and 16 per cent died in a public space. 

When cross-referenced with other sources of mortality data (the Coroners’ Office and the Central Statistics Office), incidence of death once the person was admitted to hospital was very low.  This suggests that the highest risk of mortality occurs prior to reaching hospital and indicates that overdose prevention and management must be delegated to ambulance crews and possibly to drug users themselves. 

On the international scene, Sporer2reviewed the international evidence on overdose prevention and reported that heroin overdose has become a common and preventable cause of death in recent years. Some combination of increasing treatment with opiate substitutes, community peer education, family support groups, supervised injecting facilities, and making naloxone (the antidote to opiates) available at home may be needed to have any practical effect on mortality from overdose.  A number of pilot programmes involving education of users and distribution of naloxone have begun.   These programmes’ effects on drug-related mortality, risks and benefits in relation to the use of use of naloxone, and on patterns of consumption of heroin by established users and by novices, have not been reported and should be studied carefully.

The National Medicines Information Centre3 reviewed the use of naloxone in the management of opiate-dependence syndrome.  The authors reported that naloxone has been used for many years as an emergency room treatment for the management of opiate overdose.  According to the authors, evaluation of its use in this setting suggests that it was associated with a low rate of serious adverse effects but the data involved small numbers of patients.  Its administration by trained ambulance staff in the pre-hospital setting resulted in fewer hospital admissions, but follow-up data on the patients were lacking in many cases.  Although the availability of take-home naloxone for use by friends and relatives of an opiate user has been recommended by several workers, the authors report that there were no controlled trials evaluating such usage.  Furthermore, records of use from pilot studies were insufficient to undertake a benefit versus risk analysis of the use of naloxone in this setting. However, preliminary results suggested that it might be of use in these areas.  The authors stressed that naloxone administration was just one action in a sequence of actions required to prevent overdose and cautioned against a one-dimensional approach. 

They highlight the need for a combination of the following approaches:

• education on the effects of polydrug or concomitant alcohol use and the usefulness of naloxone in this situation;
• stressing the dangers of solitary injection;
• importance of calling an ambulance;
• knowledge of and practice in basic resuscitation techniques. 

Further information on the feasibility of naloxone use as an emergency treatment in the community setting would be needed before any such programme could be implemented. According to the authors, there are many logistical and medico-legal issues that would need to be dealt with before such a programme could be implemented in practice.

Taken together, these two reviews present similar findings and indicate that the management of opiate overdose requires a multi-dimensional approach, careful planning and continuous monitoring in order to learn from experience. 

Thanks are due to Ms Anne Clifton and Ms Aisling Mulligan for abstracting the data from the HIPE scheme.