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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
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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
Commonly held beliefs • Demographics • 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
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.