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

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

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

Opioid overdose deaths 1991-2005

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

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

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

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)

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

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

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

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

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

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, 189-200.