The death of Prince and the NSW Coroner’s comments on 13 deaths among injecting drug users in a month, suspected to be related to heroin has sparked media interest in fentanyl. NDARC’s Director Michael Farrell spoke to several media outlets about the drug.
“Fentanyl is 50 to 100 times more concentrated than morphine,” says Professor Farrell. “It’s very difficult for people to know just how much they are extracting from the patch and injecting. It is already a very powerful opioid and people are injecting it without being able to control how much.
“Like all opioids including heroin, fentanyl is a respiratory depressant – it interferes with the user’s ability to breathe. Because it is so concentrated people can misjudge the dose for themselves to dangerous degree.”
Polydrug use which is very common with heroin use and other opioids are a major risk to users, says Professor Farrell.
“It is quite common for users to use fentanyl and other opioids along with other substances such as alcohol and benzodiazepines which are also respiratory depressants, therefore increasing the risk of death
Despite media speculation that the recent opioid overdoses in NSW may be related to fentanyl laced heroin there is no evidence of this in Australia to date, says Professor Farrell.
“We have no evidence to support the presence of any fentanyl laced heroin in Australia. But it is a common cause of overdose deaths in the US,” says Farrell.
Fentanyl transdermal patches were first listed on the Pharmaceutical Benefits Advisory Scheme in 1999 for use in the management of chronic cancer pain.
Research published in 2013 by NDARC senior research officer Amanda Roxburgh highlighted the increase in Fentanyl related deaths in Australia in the five years to 2011.
The research found that fentanyl prescriptions increased more than fivefold in Australia over the five years to 2011 and were linked to a rise in overdose deaths among middle aged Australians.
Rates of prescribing in those aged over 80, who accounted for a quarter of total prescriptions, increased fivefold from less than 50 per 1000 population to more than 250 per 1000 population from 2005/06 to 2010/11. Rates for 40 – 49 year olds increased sixfold over the period, but from a much lower base of around 2.5 per 1000 to around 16 per 1000. Just under a half of all deaths involved fentanyl toxicity as the underlying cause of death and just over half involved additional drugs.
People aged over 80 accounted for the majority of the prescriptions. However Australians aged under 47 years accounted for the majority (75%) of the overdoses. Only a third (36%) of the deaths involved people who had been prescribed fentanyl. More than half (54%) of the deaths involved people who inject drugs (95 per cent of whom had injected fentanyl prior to death).
The majority (95%) of fentanyl prescriptions over the study period were for patches and to inject it users need to extract the drug and dissolve it.
The discrepancy between the age group of those receiving most prescriptions for fentanyl and those dying of fentanyl related overdose suggest that these deaths are occurring among people who are misusing it and for whom it was not originally prescribed (64% of deaths had no record of fentanyl being prescribed).
Lead author of that study, Amanda Roxburgh, said: “Our study, the first to track fentanyl related deaths in Australia in detail, indicates the need for considered measures around prescribing to reduce the ability of people to stockpile these drugs and obtain them through 'doctor shopping' (visiting several doctors to obtain more prescriptions). Real time monitoring, which allows health professionals to monitor prescribing history, makes it harder for individuals to 'doctor shop', and may assist in reducing rates of diverted fentanyl."
While rates of deaths from fentanyl had increased over time relative to prescription rates, fentanyl related deaths were still significantly lower than oxycodone related deaths (another prescription opioid) which accounted for 465 deaths over the period and which were between two and five times more common than fentanyl related deaths relative to the number of prescriptions issued.
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