Risk factors

Opiates are present in the blood of most victims of overdose death due to illegal substances, although concentrations found in toxicology vary widely, and other substances are very frequently present (Figure 13 OL) (30).

Several risk factors for opiate overdose are known: administration by injection; concomitant use of other depressant drugs (e.g. alcohol or benzodiazepines); loss of tolerance after a period of abstinence (e.g. on release from prison or discharge from a treatment programme); injecting in public places (which may be associated with the use of untested drugs); a long history of opiate dependence; older age (perhaps as a result of concomitant liver or respiratory diseases); and possibly unexpected changes in purity (although studies present divergent results). In addition, most opiate overdoses take place in the presence of other users and, as death is usually not immediate, there is time for intervention. Unfortunately, however, bystanders are often unable or unwilling to assist because of either lack of knowledge or fear of police intervention.

The fact that risk factors are well known and that death is not immediate should mean that it is possible to prevent a significant proportion of drug overdoses, or at least to prevent a fatal outcome in many cases, and stresses the need to implement appropriate interventions, especially for older injectors and those who have lost tolerance after a period of relative abstinence.

(30) See Statistical Table 25: Summary of characteristics of victims of acute drug-related death in the EU countries.