Australians are using the highly addictive opioid fentanyl at concerning levels, with consumption doubling in regional areas, a new report has found.

The fifth national wastewater drug monitoring program report, published on Tuesday, sounded the alarm about a surge in the consumption of fentanyl, the prescription drug experts say is 50 to 100 times more concentrated than morphine.

“While fentanyl consumption measured by the program reflects both licit and illicit use, increased consumption is of concern as the high potency of fentanyl greatly increases the risk of overdose,” the Australian Criminal Intelligence Commission said.

The population-weighted average consumption of fentanyl in April 2018 was the highest since the wastewater monitoring program began in 2016, the report said.

Researchers evaluated wastewater from 47 treatment plants across the country, testing for 12 substances including nicotine and alcohol. It said the sampling undertaken in April 2018 covered about 54% of the Australian population.

Compared with 23 other countries that hold similar data, Australia was second behind the United States for MDMA, cocaine, amphetamine and methylamphetamine use.

The report found population-weighted use of methylamphetamine – commonly known as ice – decreased between December 2017 and April 2018, but it remained the most highly consumed illicit drug in Australia.

An estimated 8.3 tonnes of the drug is consumed in Australia every 12 months, according to previous data. Per capita, meth use was highest in Darwin of all the capital cities, while regional Western Australia recorded the highest consumption in the regions.

Cocaine use decreased in capital cities and regional sites and was highest in New South Wales, with Victorians consuming less than half as much. High levels of cocaine use were also recorded in the Australian Capital Territory.

Political leaders and health experts in the US have described the situation there as an opioid epidemic. Opioid overdoses accounted for more than 42,000 deaths in 2016, and fentanyl was blamed for the deaths of the musicians Prince and Tom Petty.

In Australia, a National Coronial Information Service report found there were 498 fentanyl-related deaths between January 2010 and December 2015. That marked an 18,000% increase on the previous decade.

Tuesday’s report found people in Australia’s regions consumed twice as much fentanyl on average compared to those in capital cities.

Researchers also found oxycodone consumption had “elevated consumption levels at several regional sites”, while Victorians were much more likely to consume heroin than people in other states.

The commission described oxycodone and fentanyl as drugs that had a “therapeutic application”, but were also “diverted to the illicit market”.

“Regional areas had average oxycodone use well above capital city sites in many states,” the report said, noting use was highest in regional Victoria and Hobart.

Overall, nicotine and alcohol were the highest consumed substances among the 12 tested for.