Latest data reveals a decline in use of low-dose codeine in 2018, but is there more to the story?

UNSW’s National Drug & Alcohol Research Centre (NDARC) has released the latest statistics gathered on illicit drug use across Australia.

Its Illicit Drug Reporting System (IDRS) is an ongoing illicit drug monitoring system which has been conducted in all states and territories of Australia since 2000.

According to the data, NDARC reports that the use of low dose codeine for non-medicinal or pain purposes remained relatively stable from 2013-2017.

This was followed by a significant decline in 2018 (from 14% in 2017 to 3% in 2018; p<0.001).

However the researchers say it is “unclear” whether this decline was due to the legislative changes, as participants could only report use occurring in the last six months but prior to rescheduling in February 2018.

Source: Drug Trends, NDARC.

Both users of stimulants and those who inject drugs report high rates of codeine use, but following the codeine scheduling change, the majority of both groups reported taking ‘no action’.

Meanwhile about a tenth said they ‘stopped using low-dose codeine’ in response to the change, while a further 3-5% said they ‘stockpiled low-dose codeine’.

Six per cent of stimulant users and 3% of those who inject drugs said they adapted to the change by obtaining codeine not prescribed to them.

A small proportion took action by gaining a prescription, with more gaining a prescription for high-dose codeine.

Slide from the NDARC Symposium 2018, where Dr Amy Peacock presented the research results. Image: AJP

Slide from the NDARC Symposium 2018, where Dr Amy Peacock presented the research results. Image: AJP

In 2018, 27% of the national sample reported recent use of any codeine (low- or high-dose, the former prescribed or OTC) on a median of seven days (IQR 3-30 days).

Seventeen per cent reported recent high-dose codeine use (12% prescribed; 6% non-prescribed) on a median of seven days, and 12% reported recent low-dose codeine use (7% OTC: 3% prescribed and 2% non-prescribed) on a median of six days.

Meanwhile the rate and frequency of recent fentanyl use has remained low and stable since monitoring began.

In 2018, 8% of the national sample reported using fentanyl in the six months preceding interview (2% prescribed; 7% nonprescribed), with use highest in QLD (16%).

Frequency of use also remained stable relative to previous years, with participants reporting use on a median of three days in the past six months.

“Deaths from opioids have almost doubled in the past decade in North America, the most marked rise as been associated with high potency fentanyl and fentanyl analogues,” explains Associate Professor Raimondo Bruno from the University of Tasmania, who contributed to the research.

“It’s not just the US, we’re seeing Canada is struggling quite significantly with an overdose crisis, the majority have fentanyl associated with them and increasingly so.”

However thankfully this trend hasn’t been mirrored in Australia.

“Fentanyl sales are trending downwards in Australia, these are positive signs in relation to community utilisation,” says A/Prof Bruno.

“Only a very very small proportion report misuse of fentanyl,” he said.

Methadone use (including liquid and tablets) has remained relatively stable since monitoring began, with a small increase in use from 2017 to 2018 (p=0.045).

After a gradual increase from 2005-2012, rates of recent oxycodone use have been declining.

In 2018, 17% of the national sample had recently used oxycodone (3% prescribed; 14% non-prescribed), the lowest rate of use since monitoring began in 2000.

After remaining relatively stable from 2001-2007, rates of recent morphine use have been declining from 2008 onwards.

Rates of any buprenorphine use have declined from 2006 onwards.

Rates of past six month buprenorphine-naloxone use have remained relatively stable over the past decade, with a small decrease in use from 2017 to 2018. This was driven by a decrease in non-prescribed use.

Deaths from opioid use on the rise

Despite declining rates of pharmaceutical opioid use in 2018, NDARC research also shows that rates of deaths from opioid use have been rising among Australians aged 15-64 since 2007.

Just over 1000 of these occurred in 2016 alone (6.6 per 100,000 people).

Compared to 3.8 per 100,000 people in 2007, this represents an increase over the last 10 years, although Australian rates have not yet reached those seen in North America.

In 2016, two-thirds (65%) of opioid deaths were attributed to pharmaceutical opioids, and a further one quarter (24%) to heroin.

About half of deaths (48%) were attributed to natural and semi-synthetic opioids (e.g. morphine, codeine, and oxycodone).

About one-fifth (21%) were attributed to synthetic opioid analgesics (e.g. fentanyl and tramadol), and a further fifth (20%) were attributed to methadone.

Almost half (45%, n=475) of opioid-induced deaths recorded benzodiazepines as contributing to the death.

The majority (85%) of deaths in 2016 were considered accidental.

Unfortunately the data does not include a breakdown between prescription medications and diverted medications, however NDARC confirms the opioids are of pharmaceutical origin.

The NDARC team says it is looking into undertaking further analyses of these data using other more detailed sources to ascertain what proportion of deaths can be attributed to use of pharmaceutical opioids directly prescribed to the person versus not prescribed to them.

“One of the most important and effective strategies to reduce overdoses is increasing the availability of opioid substitution therapy for people who have developed opioid dependence and encouraging engagement and retention in this treatment,  Dr Amy Peacock, program lead for Drug Trends at UNSW and NDARC Senior Research Fellow, told AJP.

“We also need to encourage Australians at risk of having or witnessing an overdose to carry and administer naloxone.

“This is available over-the-counter in pharmacies and easily administered to temporarily reverse the effects of an opioid overdose, allowing time to seek medical help.”

See NDARC’s Australian Drug Trends 2018 research here

See NDARC’s research on opioid-induced deaths here