Report: Drug overdoses in Aotearoa 2025
Every year, well over a hundred New Zealand families lose a loved one due to accidental overdose.
Each number in this report represents a real person who has left behind broken hearts, unfulfilled dreams and a grieving whānau.
Accidental overdose deaths are preventable. Yet they continue to take an unacceptable toll in Aotearoa.
On average we lose almost three people every week.
We can turn this around, but we urgently need to change our approach.
Our overdose prevention plan (PDF, 469 KB) has a comprehensive list of meaningful actions we can take, including specialist overdose prevention services, an expansion of harm reduction approaches, access to naloxone, and better preparedness for rapidly changing drug supplies.
There is currently no national standard for tracking overdose numbers and no national body tasked with counting them.
This report is compiled by the NZ Drug Foundation – an independent non-governmental organisation – based on data we request each year from the Office of the Chief Coroner. There should be a more sustainable official mechanism to track these numbers, because preventing overdose is not possible without surveillance.
In the absence of a national overdose surveillance system, we attempt to access information that helps us to estimate the harm and look at trends that could inform policy and services. In this report, beyond coronial data, we also cover hospital presentation data for drug poisonings (non-fatal overdoses) that we access under an Information Sharing Agreement with Te Whatu Ora.
We focus on coronial data in this paper because, despite its limitations and delays, it is the timeliest way we can access overdose information.
Acknowledgements
We want to acknowledge the teams that assisted us in accessing the data, including the Office of the Chief Coroner (Ministry of Justice), and National Collections Data Services (Te Whatu Ora).
In particular, we want to acknowledge Chris Lewis from Te Whatu Ora National Collections Data Services team for his continued guidance.
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Overdose deaths in Aotearoa
Coronial data
This section examines data from the coronial office of fatal, accidental overdoses cases in New Zealand between 2016 and 2024.
This data only includes accidental drug-overdose deaths and excludes intentional self-harm or suicide deaths. It also does not include other drug-related death causes, such as communicable diseases, short- or long-term health complications and chronic health conditions that may occur as a result of drug use.
The report excludes cases prior to 2016 due to inconsistency in toxicology detection and data collection.
1,295 people died of accidental drug overdose between 2016 and 2024.
Despite a slight decrease in provisional cases in 2024, the number of fatal overdoses has remained stubbornly high.
Overdose deaths
2016–2024
*Coronial inquiries take time
Recent cases are more likely to be under active investigation. This means that the total numbers we present for recent years are provisional and are subject to change.
For 2024, most cases we analysed are still considered active cases under coronial inquiry at the time of publishing.
Coronial data in New Zealand has limitations and cannot be used on its own as a definitive measure of overdose mortality. Rather, it should be considered an indicator of patterns in overdose deaths. Coronial data is limited by a significant delay in closing cases, which can take several years.
Data on active cases is limited. Sometimes the drugs implicated in a death or the overall cause of death is changed when a case is closed by the coroner. As a result, active case numbers may be under- or over-reported in this dataset. In the case of emerging new psychoactive substances (NPS) such as nitazenes, we are unable to confirm how many active cases involved these substances.
This report has excluded cases considered by a coroner to be intentional self-harm (suicide). However, sometimes an active case is thought to be intentional, and is later closed as an accidental overdose, or the other way around. Such cases may result in overcounting or undercounting of overdose deaths.
Coronial data relies on searching a database for keywords and is sensitive to any variation in the method of data extraction.
All of these limitations result in notable year-to-year fluctuation in the data that we receive from the coronial office.
Prioritisation
In cases where multiple drug types were detected in toxicology results, we have attributed a case as being caused by a drug class based on the following prioritisation:
- Opioid drugs
- Synthetic cannabinoids
- Benzodiazepines
- Alcohol
- Stimulants
- Other drugs (including antipsychotics, SSRIs, GHB/GBL)
- Hallucinogens
To determine this order, we looked at drug mortality data from multiple international sources (examples included in footnotes1,2) and compared the findings with overall drug availability in New Zealand. This provided us with a framework to prioritise what drug classes were most likely to lead to an overdose death. It is important to bear in mind that combining multiple drugs greatly increases the likelihood of death from overdose. In some cases, the final coroner-determined cause of mortality will differ from our allocated prioritisation of these coronial cases.
- Hedegaard, H., Bastian, B. A., Trinidad, J. P., Spencer, M., & Warner, M. (2018). Drugs Most Frequently Involved in Drug Overdose Deaths: United States, 2011-2016. National vital statistics reports: From the Centers for Disease Control and Prevention, National Center for Health Statistics, National Vital Statistics System, 67(9), 1–14.
- Martins, S. S., Sampson, L., Cerdá, M., & Galea, S. (2015). Worldwide Prevalence and Trends in Unintentional Drug Overdose: A Systematic Review of the Literature. American journal of public health, 105(11), e29–e49. https://doi.org/10.2105/AJPH.2015.302843
Changes over time
These graphs depict the number of cases for each substance group between 2016 and 2024.
Fatal overdose cases by drug type: Active and closed cases
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Opioids
e.g., morphine, methadone, heroin, codeine, fentanyl, nitazenes
Fatal opioid overdoses: Active and closed cases
- Opioids are by far the biggest contributor to overdose deaths in New Zealand.
- Over a third (39.3%) of closed opioid overdose cases involved more than one opioid (for example, codeine and fentanyl).
- The risk of overdose from opioids increases when a person also takes another depressant drug. Between 2016 and 2024, 93.1% of closed opioid overdose cases also involved at least one other depressant drug (e.g., another opioid, benzodiazepine, synthetic cannabinoid, etc.).
- This year marks the first time we have seen deaths from nitazenes – a family of potent synthetic opioids – appear in official coronial data.
Synthetic cannabinoids
Fatal synthetic cannabinoid overdoses: Active and closed cases
- Synthetic cannabinoid overdose deaths started to increase in 2017 and peaked in 2018, when New Zealand experienced a synthetic cannabinoid overdose crisis.
- Two synthetic cannabinoids were responsible for most of these deaths – AMB-FUBINACA and 5F-ADB.
- Synthetic cannabinoid overdoses have decreased since 2019 and remain relatively stable.
- In 2021, China banned the production of most synthetic cannabinoids on the market. This meant that the domestic supply of these drugs in New Zealand has substantially reduced.
Benzodiazepines
e.g., alprazolam (Xanax), diazepam, etizolam, bromazolam
Fatal benzodiazepine overdoses: Active and closed cases
- • Overdoses involving benzodiazepines have steadily increased over the last five years.
- Diazepam was the most common benzodiazepine featured in closed overdose cases, followed by clonazepam. Pharmaceutical data from 2021 to 2024 does not show that these were prescribed more often than other benzodiazepines.
- Benzodiazepines are most dangerous when mixed with other depressant drugs. Of the closed cases that involved benzodiazepines, 92.3% also involved at least one other depressant drug (e.g., alcohol or codeine).
Stimulants
e.g., methamphetamine, methylphenidate, synthetic cathinones
Fatal stimulant overdoses: Active and closed cases
- Stimulant overdose deaths increased in 2024. Because of the small numbers, these are subject to large year-to-year variations.
- Whether or not it was the cause of death, a stimulant was present in 25.3% of all closed overdose cases. Of these, 57.8% featured an amphetamine (methamphetamine/amphetamine).
Overdose cases involving alcohol
Alcohol features in many overdose cases, particularly those where more than one substance is detected. Alcohol can add to the risk of overdose death, particularly when it is mixed with other depressant drugs such as opioids, benzodiazepines or synthetic cannabinoids. This graph shows all cases where alcohol was present, whether or not it was the likely cause of death.
Between 2016 and 2024, alcohol was involved in at least 43% of all overdose cases.
Multiple substances and fatal overdoses
Most fatal overdoses in New Zealand involve more than one drug or medicine. Over half of all closed cases between 2016 and 2024 involved at least four different substances and 45.8% involved five or more.
Number of substances detected in overdose deaths (closed cases): 2016–2024
Most overdose cases involved at least one type of depressant (such as an opioid, a benzodiazepine or alcohol) and many cases involved several different depressants.
Number of depressant drugs in overdose deaths (closed cases): 2016–2024
Novel substances
Novel psychoactive substances (NPS) are manufactured to mimic the effects of well-known illicit drugs. This is a wide group of substances that includes synthetic cathinones (‘bath salts’), synthetic cannabinoids (synnies), novel benzodiazepines (e.g., etizolam, bromazolam) and novel synthetic opioids (e.g., nitazenes).
NPS can be difficult to test for, and some are not part of routine toxicology screening.
NPS appeared in 9.1% of all closed overdose cases from 2016–2024.
The majority of these were synthetic cannabinoids, but novel stimulants, benzodiazepines and opioids also featured in the data.
Medicines and fatal overdose
Medicines are involved in many overdose deaths in New Zealand.
While we don’t know whether they were used as prescribed, or if they were diverted or illicitly manufactured, it is important to consider how medicines can interact with illicit drugs.
Over two thirds of all closed cases from 2016–2024 involved at least one medicine.
Medicines involved in overdose deaths (closed cases): 2016–2024
Some medicines feature more heavily in overdose death cases. 17 different medications featured over 50 times each in closed cases. Diazepam, paracetamol, zopiclone and codeine were the most common medicines appearing in closed overdose cases.
Ten medicines most commonly appearing in overdose deaths (closed cases): 2016–2024
Overdose deaths by ethnicity
The graph below presents the average yearly mortality rates among Māori and non-Māori aged 15 or over. Concerningly, this rate is 2.8 times higher among Māori than non-Māori.
Annual accidental overdose mortality rate – excluding alcohol
per 100,000 population aged 15 and over
2016–2024
Non-fatal overdoses
Drug poisoning presentations: public hospital discharge data
A non-fatal overdose is a major predictive factor for a future fatal overdose.
Very little research has been done to determine the incidence of non-fatal overdose in New Zealand. In this section, we present the hospitalisation data from the National Minimum Dataset (NMDS), provided to the NZ Drug Foundation under an Information Sharing Agreement with Te Whatu Ora Data Services team.
This data is most likely only the tip of the iceberg of non-fatal drug overdoses in Aotearoa. Our analysis only captures cases where people presented to the hospital, were assessed and either admitted, transferred, or discharged immediately. It does not include people who were treated by ambulance teams, received help from members of the community, or presented to after-hours clinics or GPs.
Many people who suffer a non-fatal overdose don’t receive any help at all. Some may recover without treatment, while others sadly may die before getting help and end up being captured in fatal overdose figures.
The NMDS data we present covers all DHBs and uses the same measures across all regions between 2015 and 2024. We only included cases of people aged 15 and over in the data.
We present cases where the ICD-10 diagnostic code for the primary diagnosis included poisonings with the following substances:
- Opioids
- Stimulants
- Cannabis
- Hallucinogens
- Other narcotics and psychotropics (this category includes synthetic cannabinoids)
- Benzodiazepines (and barbiturates: <10 cases overall)
- Alcohol
We believe that the criteria for selection of cases are conservative and will likely result in undercounting of accidental drug poisoning cases. We removed all cases where there were any codes present that could indicate intentional self-harm or poisoning by assault. We did not include cases where the substance involved was unknown. Cases where poisonings were present as non-primary diagnosis only were also excluded.
Anecdotal evidence suggests that occasionally cases that should have been classified as accidental poisonings are misclassified as intentional self-harm.
This analysis assumes the validity of clinical diagnoses recorded and does not include toxicology data. Because of the limitations of ICD-10 coding and lack of toxicological data, this analysis is unable to provide information on NPS poisonings.
There may be small changes in the data we report on year-by-year, due to data-extract coding variations.
It is important to remember that not all accidental poisonings covered in this analysis resulted from deliberate ingestion of a substance. While this would be relatively rare among adults, some of the cases may include unknowingly consuming a substance that resulted in hospital presentation.
Hospital presentations for drug poisonings in 2024
In 2024, there were 582 hospital presentations for drug poisonings. The most common implicated substance class was opioids, followed by stimulants and benzodiazepines.
Hospital discharges by substance type 2024
10-year trends in drug poisonings resulting in hospital presentation
Hospitalisation trends for most substances appear to be stable or trending down over the course of ten years; however, stimulant presentations have increased since 2020. With wastewater testing data showing recent significant increases in cocaine and methamphetamine consumption, we expect this increase to continue.
Concerningly, 14% of hospital presentations involved more than one depressant, which increases the risk of death.
Hospital discharges by drug type 2015-2024
Hospital presentations for drug poisonings over time by ethnicity
The number of presentations has been falling for European New Zealanders over the last five years. However, it has remained stubborn for Māori.
Hospital discharges by ethnicity
Deaths among people seen at New Zealand hospitals for drug poisoning
Between 2015 and 2024, 40 (0.66%) of 6059 hospital presentations for drug poisoning resulted in death.
This relatively low rate is not surprising, considering that people who make it to a hospital are likely to receive adequate help. Another factor may be that the severity of the poisoning experienced by those presenting at hospitals was lower than among those who died before they were able to get help.
Young people are far more likely visit the hospital for drug poisoning
Relative to population size, 15–24-year-olds had the highest rate of poisoning resulting in a visit to the hospital, almost twice as high as the average rate.
Annual rate of drug poisoning presentations (per 100,000)
2015–2024
Māori experience a higher rate of drug poisoning compared to non-Māori
Relative to the population size, Māori had twice the rate of drug poisonings that resulted in hospital visits compared to non-Māori in New Zealand.
Annual rate of drug poisoning presentations (per 100,000 population aged 15 or older)
2015–2024
Summary and recommendations
The number of accidental overdose deaths in New Zealand remains stubbornly high. While a slight decrease in cases in 2024 is encouraging, 148 preventable deaths is still completely unacceptable.
Māori continue to bear the greatest burden, suffering fatal overdoses at twice the rate of non-Māori.
There are also worrying trends emerging within the data, including an increase in stimulant deaths and hospitalisations, and novel substances showing up in official coronial data for the first time.
Accidental overdoses are preventable.
We urgently need to shift our approach in order to reduce harm, prevent the fatal overdoses, and prepare ourselves for major changes in drug supply.
1. Develop and resource a comprehensive overdose programme in Aotearoa.
2. Build a national overdose surveillance system.
3. Ensure our legislation and regulations enable action.
Help us build a future free from drug harm
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