This article is part of a four-part series exploring Australia’s changing drug landscape, looking at which substances cause the most harm, who is affected, and how Australia is responding. Read the full series:
Part 1 | What Is Australia’s Most Dangerous Drug? The Answer Isn’t What Most People Think
Part 2 | Methamphetamine, Cocaine and Australia’s Changing Drug Landscape
Part 3 | You are here
Part 4 | How Australia’s Drug Landscape Has Changed — And Where It May Be Heading
If we measure danger by one devastating outcome—death—the answer changes again.
The drugs that cause the greatest number of fatalities are not necessarily the ones used by the most Australians or the ones receiving the most media attention.
In Australia, opioids remain one of the most significant contributors to drug-related deaths.
This includes both illegal opioids such as heroin and pharmaceutical opioids such as oxycodone, morphine and fentanyl.
The story of opioids in Australia is different from many other drugs because the risk is often linked not only to addiction, but also to the way these substances affect the body’s breathing system.
An opioid overdose can slow breathing to dangerous levels, particularly when combined with alcohol or other sedating substances.
Photo by Randy Laybourne on Unsplash
Opioids: Australia’s Overdose Crisis
Opioids are a group of drugs that reduce pain and create feelings of relaxation and euphoria.
They include:
- Heroin
- Oxycodone
- Morphine
- Codeine
- Fentanyl
- Other prescription opioid medications
Many opioids have legitimate medical uses. They remain important medicines for managing severe pain, cancer treatment and end-of-life care.
The problem occurs when they are misused, taken without medical supervision, combined with other substances, or used by people who develop dependence.
Unlike stimulant drugs such as methamphetamine and cocaine, which typically increase activity in the nervous system, opioids slow the body’s functions.
This creates the greatest danger:
The same effect that produces relaxation can also suppress breathing.
Why Opioids Are So Dangerous
Several factors make opioids particularly risky.
High overdose potential
A person’s tolerance to opioids can change quickly.
Someone who stops using opioids for a period and then returns to their previous dose may face a much higher overdose risk because their body is no longer adapted to that level.
Mixing substances
Many fatal overdoses involve more than one substance.
Combining opioids with:
- Alcohol
- Benzodiazepines
- Other sedatives
can significantly increase the risk of respiratory depression.
Dependence and withdrawal
Opioid dependence can develop quickly for some people.
Withdrawal symptoms may include:
- Severe cravings
- Anxiety
- Sweating
- Muscle aches
- Nausea
- Sleep disruption
Although opioid withdrawal is usually not fatal by itself, the intense discomfort can make returning to use more likely.
Prescription Opioids: The Hidden Part of the Story
When many Australians hear about opioid deaths, they immediately think of heroin.
However, prescription opioids are an important part of the picture.
Medications such as oxycodone and morphine can be essential when used appropriately. The issue is not the existence of these medicines, but the risks associated with dependence, long-term use, misuse and accidental overdose.
Australia, like many other countries, has experienced increased awareness around prescription opioid harm.
This has led to:
- Improved prescribing guidelines
- Greater monitoring
- Increased awareness among healthcare professionals
- Greater emphasis on alternative pain management approaches
The challenge is finding the balance between ensuring people with genuine pain receive appropriate treatment while reducing preventable harm.
Heroin: No Longer the Same Crisis, But Still Dangerous
Heroin remains one of Australia’s most dangerous illicit drugs, particularly because of its overdose risk.
However, its role has changed.
During the late 1990s and early 2000s, Australia experienced a significant heroin overdose crisis. Public concern was high, and heroin was often considered the country’s biggest drug problem.
Today, heroin use is lower than during that period.
Several factors contributed to this change, including:
- Expanded treatment options
- Harm reduction approaches
- Changes in drug markets
- Increased availability of other substances
Despite lower prevalence, heroin continues to cause serious harm among people who use it.
A smaller number of users does not mean a smaller problem for those affected.
Australia’s Drug Harm Is Not Evenly Distributed
One of the most important lessons from Australian drug data is that harm is not spread equally across the country.
Drug use patterns differ significantly between:
- States and territories
- Metropolitan and regional areas
- Different age groups
- Different communities
The drug causing the greatest concern in Sydney may not be the same drug causing the greatest concern in regional Western Australia or Tasmania.
State and Territory Differences
New South Wales
New South Wales has historically recorded significant levels of cocaine use, particularly in major urban areas.
Sydney’s size, nightlife economy and international connections contribute to a diverse drug market.
Key concerns include:
- Cocaine availability
- Stimulant use
- Pharmaceutical opioid harms
Victoria
Victoria has experienced significant challenges related to opioid harm.
Melbourne has also been a major centre for stimulant and recreational drug markets.
Key concerns include:
- Opioid-related harm
- Methamphetamine use
- Increasing complexity of recreational drug use
Queensland
Queensland has unique challenges due to its large geographical area and significant regional population.
Regional communities can experience higher impacts from:
- Methamphetamine
- Cannabis
- Prescription drug misuse
Distance from major treatment services can make access to support more difficult.
South Australia
South Australia has historically recorded significant concern around stimulant use.
Methamphetamine has been an important public health issue, with treatment services reporting ongoing demand.
Western Australia
Western Australia’s geography creates unique challenges.
Large distances between communities mean that regional and remote areas may experience different patterns of harm compared with Perth.
Concerns include:
- Methamphetamine
- Cannabis
- Alcohol-related harm
- Access to treatment services
Tasmania
Tasmania has historically shown higher rates of some forms of drug use compared with national averages.
Challenges include:
- Cannabis use
- Methamphetamine
- Prescription drug misuse
- Limited access to specialist services in some regions
Australian Capital Territory and Northern Territory
Smaller populations mean statistics can fluctuate significantly from year to year.
The Northern Territory faces additional challenges related to:
- Remoteness
- Service access
- Alcohol and drug-related harm
The ACT has a different profile due to its urban population and demographic characteristics.
Regional Australia: A Different Reality
Drug harm in regional Australia is often different from metropolitan areas.
Research consistently shows that people living outside major cities can experience:
- Higher rates of some substance-related harms
- Greater barriers to treatment
- Longer travel distances for healthcare
- Fewer specialist services
This does not mean regional Australians use more drugs across every category.
Instead, it highlights that the consequences can be greater when support systems are harder to access.
A person living in a major city may have several treatment options nearby.
Someone in a remote community may need to travel hundreds of kilometres for equivalent support.
The Numbers Tell Only Part of the Story
Statistics are important because they help governments understand where resources are needed.
But behind every number is a person.
A drug-related death is not only a medical statistic.
It represents:
- A family losing someone they love
- Children losing a parent
- Friends losing someone important
- Communities experiencing grief
Likewise, addiction statistics represent real people dealing with complex challenges.
Effective responses require more than simply asking:
“What drug is the worst?”
The more useful questions are:
- Why do people develop dependence?
- What support prevents harm?
- How do we improve access to treatment?
- How do we reduce stigma so people seek help earlier?
So What Is Australia’s Most Dangerous Drug?
After looking at prevalence, addiction, community impact and deaths, the answer becomes clearer.
There is no single drug that dominates every category.
| Type of harm | Drug category that stands out |
|---|---|
| Most users | Cannabis |
| Strongest community impact | Methamphetamine |
| Increasing recreational use | Cocaine |
| Highest overdose risk | Opioids |
| Significant historical impact | Heroin |
| Emerging concerns | Ketamine and synthetic drugs |
The “most dangerous drug” depends on the question being asked.
But one conclusion is clear:
Australia’s drug problem is not one problem. It is many different problems happening at the same time.
This article is part of a four-part series exploring Australia’s changing drug landscape, looking at which substances cause the most harm, who is affected, and how Australia is responding. Read the full series:
Part 1 | What Is Australia’s Most Dangerous Drug? The Answer Isn’t What Most People Think
Part 2 | Methamphetamine, Cocaine and Australia’s Changing Drug Landscape
Part 3 | You are here
Part 4 | How Australia’s Drug Landscape Has Changed — And Where It May Be Heading
Need Support?
If you or someone you know is affected by alcohol or drug use, support is available.
The Australian Government’s National Alcohol and Other Drug Hotline provides free and confidential advice, information and support, including help finding local treatment services.
Phone: 1800 250 015