1. Heroin overdose: Myths, facts and intervention
Shane Darke, PhD
Professor
National Drug and Alcohol Research Centre
University of New South Wales

2. Mortality and heroin use
Annual mortality rates of 1-3%
Excess mortality rate 13 times that of peers
Major cause of death is overdose
25:1 ratio of non-fatal to fatal

3. Mechanisms of overdose
Heroin (diacetylmorphine) rapidly hydrolysed to 6-monoacetylmorphine, and then to morphine
CNS depressant
Primary mechanism of death is depression of respiration, resulting in hypoxia and death
Cardiac arrest may also occur

4. Opioid overdose deaths 1991-2005

5. Commonly held beliefs Demographics Toxicology Circumstances of death
Young, inexperienced users
Toxicology
Large doses of drug (as “overdose” suggests)
Purity
Heroin is the cause
Impurities
Circumstances of death
Street based
Rapid death
Parasuicide
Non-injecting routes safe

6. Demographics of cases Average age early 30s. Few young cases Male
Long-term, dependent users
Mostly unemployed
Not in treatment at time of death

7. Toxicology of overdose
In many cases, blood morphine concentrations are low
Similar to those of living heroin users, or to those who died from other causes (e.g. homicide)
Purity only moderately associated with overdose deaths

8. Toxicology of overdose
Heroin only overdose not the norm
In 75% of cases other drugs also found
Major drugs detected
Alcohol (50% of cases)
Benzodiazepines (25-30% of cases)
Antidepressants (tricyclics) (10% of cases)
Impurities rare (mostly caffeine, saccharine)

9. Circumstances of overdose
Most overdoses occur at home
Weekly peak on Thursdays/Fridays
Suicides constitute only 5% of cases
Reduced risk, but non-injecting deaths do occur

10. Circumstances of overdose
Instant death not the norm
No intervention prior to death in most cases (even when others present)
Recent release from prison/detoxification increased risk

11. Natural history Older users and relapse Liver disease
A quarter of older cases have cirrhotic livers
Lower morphine concentrations amongst older cases

12. Beliefs and facts Belief Fact Young, inexperienced
Older, very experienced
Large doses of heroin
Purity
Heroin is the cause
Impurities
Low morphine concentrations
Moderate association
Polydrug use the norm
Rare and usually benign
Street based
Rapid death
Parasuicide
Non-injecting safe
Mostly at home
Rapid death not the norm
Almost all are accidents
Safer, but deaths occur

13. Prevention strategies
Treatment
Long-term, stable treatment (RR, MT)
Polydrug use
Alcohol
Improved response by IDU
Ambulances
CPR
Naloxone provision

14. References
Darke, S., Degenhardt, L. & Mattick, R. (2007) Mortality amongst illicit drug users: epidemiology, causes and intervention. Cambridge: Cambridge University Press.
Darke, S. & Hall, W. (2003) Heroin overdose: research and evidence-based intervention. Journal of Urban Health: Bulletin of the New York Academy of Medicine, 80,