Sunday, June 11, 2006
OPIATE ADDICTION AND LIVER DISEASE
THE mystery of long-term heroin users dying by overdose despite experience with the drug may have been solved by a study linking overdoses with liver disease.
Researchers have puzzled for years about why heroin users defy the laws of experience and mortality that apply to others who practise risky activities and are more likely to survive as they age. Instead heroin overdoses are more likely to occur among people who have used the drug in a similar way for many years than among novice users.
The NSW Drug and Alcohol Research Council investigated 841 deaths due to opioid toxicity and found 10 per cent of those aged 35 to 44 and a quarter of those aged over 44 had been diagnosed with cirrhosis.
This could make them more susceptible to overdose, said Professor Shane Darke from the Drug and Alcohol Research Council at the University of NSW.
"They've got these phenomenally high rates of … liver disease," Dr Darke said. "If they hadn't died of overdose, they would have died of cirrhosis."
A 70 per cent incidence of hepatitis C and a high rate of alcohol consumption may account for the likelihood of liver disease, the study said.
Nearly a quarter of those studied had multiple-organ disease. "They're drinking, they're using heroin frequently, their bodies are just wearing out," Dr Darke said.
In 2004, 357 Australians died of heroin and opioid overdose. Those aged 25-34 comprised the biggest group at 43 per cent, followed by people aged 35 to 44 (28 per cent), 45 to 54 (18 per cent) and 15 to 24 (10 per cent).
Meanwhile, a significant number of injecting drug users are not being tested for hepatitis and other blood-borne diseases despite national public health policies, a survey has found.
Transmission of blood-borne viruses among drug users is still a considerable problem in Australia, with hepatitis B and C still spreading rapidly.
A survey of 222 drug and alcohol services has found that while about 75 per cent offer some testing and vaccinations for these conditions and HIV, fewer then half do so routinely.
The study, published in the Medical Journal of Australia, also found only one-third offer these testing services routinely on site.