Risk of fentanyl overdose among clients of the Sydney Medically Supervised Injecting Centre

Development of fentanyl-specific monoclonal antibody (mAb) to antagonize the pharmacological effects of fentanyl

Fentanyl, a critical component of opioid analgesics, poses a severe threat to public health, exacerbating the drug problem due to its potential fatality. Herein, we present two novel haptens designed with different attachment sites conjugated to keyhole limpet hemocyanin (KLH), aiming to develop an efficacious vaccine against fentanyl. KLH-Fent-1 demonstrated superior performance over KLH-Fent-2 in antibody titer, blood-brain distribution, and antinociceptive tests. Consequently, we immunized mice with KLH-Fent-1 to generate fentanyl-specific monoclonal antibodies (mAbs) using the hybridoma technique to compensate for the defects of active immunization in the treatment of opioid overdose and addiction. The mAb produced by hybridoma 9D5 exhibited the ability to recognize fentanyl and its analogs with a binding affinity of 10-10 M. Subsequently, we developed a human IgG1 chimeric mAb to improve the degree of humanization. Pre-treatment with murine and chimeric mAb significantly reduced the analgesic effect of fentanyl and altered its blood-brain biodistribution in vivo. Furthermore, in a mouse model of fentanyl-induced respiratory depression, the chimeric mAb effectively reversed respiratory depression promptly and maintained a certain level during the week. The development of high-affinity chimeric mAb gives support to combat the challenges of fentanyl misuse and its detrimental consequences. In conclusion, mAb passive immunization represents a viable strategy for addressing fentanyl addiction and overdose.

Modeling of overdose and naloxone distribution in the setting of fentanyl compared to heroin

BACKGROUND

Fentanyl has replaced most other non-prescribed opioids in much of North America. There is controversy over whether a hypothetical reduced efficacy of naloxone in reversing fentanyl is a major contributor to the coincident rising overdose mortality.

METHODS

We modified an existing Markov decision analytic model of heroin overdose and naloxone distribution to account for known risks of fentanyl by adjusting overdose risk, the likelihood of death in the event of overdose, and the proportion of cases in which available naloxone was administered in time to prevent death. We assumed near-universal survival when naloxone was administered promptly for heroin or fentanyl overdose, but allowed that to decline in sensitivity analyses for fentanyl. We varied the proportion of use that was fentanyl and adjusted the modified parameters accordingly to estimate mortality as the dominant opioid shifted.

RESULTS

Absent naloxone, the annual overdose death rate was 1.0% and 4.1% for heroin and fentanyl, respectively. With naloxone reaching 80% of those at risk, the overdose death rate was 0.7% and 3.6% for heroin and fentanyl, respectively, representing reductions of 26.4% and 12.0%. Monte Carlo simulations resulted in overdose mortality with fentanyl of 3.3-5.2% without naloxone and 2.6-4.9% with naloxone, with 95% certainty. Positing reduced efficacy for naloxone in reversing fentanyl resulted in 3.6% of fentanyl overdose deaths being prevented by naloxone.

CONCLUSIONS

Heightened risk for overdose and subsequent death, alongside the time-sensitive need for naloxone administration, fully account for increased mortality when fentanyl replaces heroin, assuming optimal pharmacologic efficacy of naloxone.

CommunityStat: A Public Health Intervention to Reduce Opioid Overdose Deaths in Burlington, Vermont, 2017-2020

From 2017 to early 2020, the US city of Burlington, Vermont led a county-wide effort to reduce opioid overdose deaths by concentrating on the widespread, low-barrier distribution of medications for opioid use disorder. As a small city without a public health staff, the initiative was led out of the police department-with an understanding that it would not be enforcement-oriented-and centered on a local adaptation of CompStat, a management and accountability program developed by the New York City Police Department that has been cited as both yielding improvements in public safety and overemphasizing counterproductive police performance metrics if not carefully directed. The initiative was instrumental to the implementation of several novel interventions: low-threshold buprenorphine prescribing at the city's syringe service program, induction into buprenorphine-based treatment at the local hospital emergency department, elimination of the regional waiting list for medications for opioid use disorder (MOUD), and the de-facto decriminalization of diverted buprenorphine by the chief of police and county prosecutor. An effort by local legislators resulted in a state law requiring all inmates with opioid use disorder be provided with MOUD as well. By the end of 2018, these interventions were collectively associated with a 50% (17 vs. 34) reduction in the county's fatal overdose deaths, while deaths increased 20% in the remainder of Vermont. The reduction was sustained through the end of 2019. This article describes the effort undertaken by officials in Burlington to implement these interventions. It provides an example that other municipalities can use to take an evidence-based approach to reducing opioid deaths, provided stakeholders assent to sustained collaboration in the furtherance of a commitment to save lives. In doing so, it highlights that police-led public health interventions are the exception, and addressing the overdose crisis will require reform that shifts away from criminalization as a community's default framework for substance use.

Antisocial Personality Disorder as a Risk Factor for Opioid Use: The Dual Mediating Roles of Antisocial Attitudes and Self-Control

Antisocial personality disorder is a risk factor for opioid use. There is a dearth of research which examines self-control and moral disengagement as potential mediators of this relationship. This study utilized data from the Pathways to Desistance study in analyses. Generalized structural equation modeling was utilized to test for mediation of the relationship between antisocial personality disorder and opioid use. Bootstrapped standard errors were computed so that a Clogg Z test could be estimated to determine if identified mediation effects significantly differed. Results indicated that a likely diagnosis of antisocial personality disorder increased risk for opioid use. Inclusion of moral disengagement and self-control into the model resulted in attenuation of this effect to non-significance and reduced the magnitude of the effect by around 45%. The contribution of both constructs to the total indirect effect did not significantly differ and only the total indirect effect was significant.

Opportunities to Offer Harm Reduction to People who Inject Drugs During Infectious Disease Encounters: Narrative Review

Increased rates of overdose (OD) and blood-borne infections have been associated with injection drug use (IDU). This increasing overlap between IDU-related infectious diseases (ID) is a byproduct of the opioid OD crisis, especially with the transition to synthetic opioids with faster onset and shorter duration leading to potentially more frequent injections. ID specialists are uniquely positioned to positively impact the opioid OD crisis by capitalizing on opportunistic moments of engagement during clinical encounters with people who inject drugs (PWID). Harm reduction services should therefore be expanded and offered to PWID in ID settings to reduce rates of OD, infection, and hospitalization. Major target areas include (1) teaching and distribution of materials related to safer injection practice such as sterile injection supplies, fentanyl test strips, and naloxone; (2) increased screening and access to pre-exposure prophylaxis and postexposure prophylaxis; and (3) initiation of medications for opioid use disorder. Incorporating these strategies in various treatment settings can expand treatment access, improve patient outcomes, and reduce stigma associated with IDU.

The fentanyls: a 'future threat' for Australia?

OBJECTIVE

The fentanyls have emerged as a significant public health threat in North America but much less so in Australia. We sought to identify reasons for this discrepancy and highlight harm reduction approaches that may mitigate a future Australian fentanyl epidemic.

CONCLUSIONS

Differences in drug use 'culture' and a supply of cheap high-quality methamphetamine in Australia may be reasons for the observed difference in fentanyl-related harm. More worryingly, it is possible that Australia is following North American trends and that the fentanyl epidemic is still to come.

Comparing rates and characteristics of ambulance attendances related to extramedical use of pharmaceutical opioids in Victoria, Australia from 2013 to 2018

BACKGROUND AND AIMS

Despite increases in opioid prescribing and related morbidity and mortality, few studies have comprehensively documented harms across opioid types. We examined a population-wide indicator of extramedical pharmaceutical opioid-related harm to determine if the supply-adjusted rates of ambulance presentations, the severity of presentations or other attendance characteristics differed by opioid type.

DESIGN

Retrospective observational study of coded ambulance patient care records related to extramedical pharmaceutical opioid use, January 2013 to September 2018.

SETTING

Australia CASES: Primary analyses used Victorian data (n = 9823), with available data from other Australian jurisdictions (n = 4338) used to determine generalizability.

MEASUREMENTS

We calculated supply-adjusted rates of attendances using Poisson regression, and used multinomial logistic regression to compare demographic, presentation severity, mental health, substance use and other characteristics of attendances associated with seven pharmaceutical opioids.

FINDINGS

In Victoria, the highest rates of attendance [per 100 000 oral morphine equivalent mg (OME)] were for codeine (0.273/100 000) and oxycodone (0.113/100 000). The lowest rates were for fentanyl (0.019/100 000) and tapentadol (0.005/100 000). Oxycodone-naloxone rates (0.031/100 000) were lower than for oxycodone as a single ingredient (0.113/100 000). Fentanyl-related attendances were associated with the most severe characteristics, most likely to be an accidental overdose, most likely to have naloxone administered and least likely to be transferred to hospital. In contrast, codeine-related attendances were more likely to involve suicidal thoughts/behaviours, younger females and be transported to hospital. Supply-adjusted attendance rates for individual opioids were stable over time. Victorian states were broadly consistent with non-Victorian states.

CONCLUSIONS

In Australia, rates and characteristics of opioid-related harm vary by opioid type. Supply-adjusted ambulance attendance rates appear to be both stable over time and unaffected by large changes in supply.

Illicit opioid use following changes in opioids prescribed for chronic non-cancer pain

Background

After decades of increased opioid pain reliever prescribing, providers are rapidly reducing prescribing. We hypothesized that reduced access to prescribed opioid pain relievers among patients previously reliant upon opioid pain relievers would result in increased illicit opioid use.

Methods and findings

We conducted a retrospective cohort study among 602 publicly insured primary care patients who had been prescribed opioids for chronic non-cancer pain for at least three consecutive months in San Francisco, recruited through convenience sampling. We conducted a historical reconstruction interview and medical chart abstraction focused on illicit substance use and opioid pain reliever prescriptions, respectively, from 2012 through the interview date in 2017–2018. We used a nested-cohort design, in which patients were classified, based on opioid pain reliever dose change, into a series of nested cohorts starting with each follow-up quarter. Using continuation-ratio models, we estimated associations between opioid prescription discontinuation or 30% increase or decrease in dose, relative to no change, and subsequent frequency of heroin and non-prescribed opioid pain reliever use, separately. Models controlled for demographics, clinical and behavioral characteristics, and past use of heroin or non-prescribed opioid pain relievers. A total of 56,372 and 56,484 participant-quarter observations were included from the 597 and 598 participants available for analyses of heroin and non-prescribed opioid pain reliever outcomes, respectively. Participants discontinued from prescribed opioids were more likely to use heroin (Adjusted Odds Ratio (AOR) = 1.57, 95% CI: 1.25–1.97) and non-prescribed opioid pain relievers (AOR = 1.75, 1.45–2.11) more frequently in subsequent quarters compared to participants with unchanged opioid prescriptions. Participants whose opioid pain reliever dose increased were more likely to use heroin more frequently (AOR = 1.67, 1.32–2.12). Results held throughout sensitivity analyses. The main limitations were the observational nature of results and limited generalizability beyond safety-net settings.

Conclusions

Discontinuation of prescribed opioid pain relievers was associated with more frequent non-prescribed opioid pain reliever and heroin use; increased dose was also associated with more frequent heroin use. Clinicians should be aware of these risks in determining pain management approaches.

Substances injected at the Sydney supervised injecting facility: A chemical analysis of used injecting equipment and comparison with self-reported drug type

Providing information about substances injected can reduce the negative impact of illicit drug consumption and support people who inject drugs to make informed decisions. In Australia, information about drugs injected relies largely on periodic self-report surveys. For the first time, the analysis of the residual content of used injecting equipment was conducted in a supervised injecting facility (SIF) located in Sydney, Australia. The aim was to gain a better understanding of the substances injected by clients through: (1) chemical analyses of the content of used syringes; (2) comparison of these results with clients' self-reported drug use; and (3) assessing the usefulness of analysing other injecting equipment to detect substances used. During one week in February 2019, syringes and other injecting equipment were collected at the Sydney SIF. Their residual content was analysed by gas-chromatography/mass-spectrometry. Heroin was the most commonly detected substance (present in 51% of syringes), followed by methamphetamine (22%) and oxycodone (10%). In addition to the main psychoactive substance, cutting agents reported in the literature were also detected in used syringes. The main psychoactive substance identified by laboratory analysis reliably corresponded with users' self-reported drug type. Analytical confirmation of substances injected allows for the provision of better targeted harm reduction messaging based on timely and objective data. The approach used is amenable to clients and feasible in the Australian SIF context. Upscaling and wider implementation could be done through Needle and Syringe Programs, and would support the early detection of harmful substances entering drug markets and better inform harm reduction strategies.

Characteristics and circumstances of heroin and pharmaceutical opioid overdose deaths: Comparison across opioids

BACKGROUND

Although much is known about the correlates of heroin overdose, less is known about pharmaceutical opioid (PO) overdose. This study aimed to examine correlates of opioid overdose deaths by opioid and compare correlates between opioids.

METHODS

Analysis of opioid overdose deaths in Australia between 2000-2015, extracted from the National Coronial Information System (NCIS). The NCIS is an online database of deaths reportable to the coroner, and contains coroner's findings, autopsy and toxicology reports. Deaths were categorized into mutually exclusive groups: 1) Heroin deaths; and 2) PO deaths (excluding heroin). PO deaths were examined by individual opioid.

RESULTS

There were 10,795 opioid overdose deaths over the study period. Relative to deaths occurring in major cities, deaths in regional/remote areas had 15.2 (95 % CI: 11.5-20.2) times the risk of being attributed to pharmaceutical fentanyl than heroin. Relative to deaths among people without a recorded history of chronic pain, deaths among people with a recorded history of chronic pain had a 1.9-10.7-fold increased risk of the death being attributed to POs than heroin. Deaths among people with a recorded history of substance use problems where the opioid was injected prior to death had 7.2 and 1.7 times the risk of being attributed to methadone and pharmaceutical fentanyl (respectively) than heroin.

CONCLUSIONS

Findings suggest the need to: educate PO consumers about the risks of overdose at the time of prescribing; increase coverage and engagement in opioid dependence treatment (particularly in regional/remote areas); and increase uptake of take-home naloxone to reduce opioid overdose mortality.

The rising crisis of illicit fentanyl use, overdose, and potential therapeutic strategies

Fentanyl is a powerful opioid anesthetic and analgesic, the use of which has caused an increasing public health threat in the United States and elsewhere. Fentanyl was initially approved and used for the treatment of moderate to severe pain, especially cancer pain. However, recent years have seen a growing concern that fentanyl and its analogs are widely synthesized in laboratories and adulterated with illicit supplies of heroin, cocaine, methamphetamine, and counterfeit pills, contributing to the exponential growth in the number of drug-related overdose deaths. This review summarizes the recent epidemic and evolution of illicit fentanyl use, its pharmacological mechanisms and side effects, and the potential clinical management and prevention of fentanyl-related overdoses. Because social, economic, and health problems that are related to the use of fentanyl and its analogs are growing, there is an urgent need to implement large-scale safe and effective harm reduction strategies to prevent fentanyl-related overdoses.

Suspected involvement of fentanyl in prior overdoses and engagement in harm reduction practices among young adults who use drugs

Background: From 2011 to 2016, the United States has experienced a 55% increase in overall overdose deaths and a 260% increase in fatal fentanyl-related overdoses. Increasing engagement in harm reduction practices is essential to reducing the rate of fentanyl-related overdoses. This study sought to examine the uptake of harm reduction practices among young adults who reported recent drug use and who were recruited for a study to assess the utility and acceptability of rapid fentanyl test strips. Methods: Between May and October 2017, 93 young adults who reported drug use in the past 30 days were recruited through word of mouth, Internet advertising, and public canvasing. Participants completed an interviewer-administered survey that assessed participants' sociodemographic and behavioral characteristics, suspected fentanyl exposure, and overdose history. We assessed harm reduction practices and other correlates associated with experiencing a suspected fentanyl-related overdose. Results: Of 93 eligible participants, 36% (n = 34) reported ever having experienced an overdose, among whom 53% (n = 18) suspected having experienced a fentanyl-related overdose. Participants who had ever experienced a fentanyl-related overdose were more likely to keep naloxone nearby when using drugs compared with those who had never experienced an overdose and those who had experienced an overdose that they did not suspect was related to fentanyl (P < .001). Additionally, experiencing a suspected fentanyl-related overdose was associated with having previously administered naloxone to someone else experiencing an overdose (P < .001). Conclusion: Those who had experienced a suspected fentanyl-related overdose were more likely to carry and administer naloxone. Future overdose prevention interventions should involve persons who have experienced a suspected fentanyl overdose and/or responded to an overdose in order to develop harm reduction programs that meet the needs of those at risk of an overdose.

Drug consumption rooms: A systematic review of evaluation methodologies

ISSUES

Drug consumptions rooms (DCR) and supervised injecting facilities (SIF) are expanding internationally. Previous reviews have not systematically addressed evaluation methodologies.

APPROACH

Results from systematic searches of scientific databases in English until June 2017 were coded for paper type, country and year of publication. For evaluation papers, study outcome, methodology/study design and main indicators of DCR/SIF 'exposure' were recorded.

KEY FINDINGS

Two hundred and nineteen eligible peer-reviewed papers were published since 1999: the majority from Canada (n = 117 papers), Europe (n = 36) and Australia (n = 32). Fifty-six papers reported evaluation outcomes. Ecological study designs (n = 10) were used to assess the impact on overdose, public nuisance and crime; modelling techniques (n = 6) estimated impact on blood-borne diseases, overdose deaths and costs. Papers using individual-level data included four prospective cohorts (n = 28), cross-sectional surveys (n = 7) and service records (n = 5). Individual-level data were used to assess safer injecting practice, uptake into health and social services and all the other above outcomes except for impact on crime and costs. Four different indicators of DCR/SIF attendance were used to measure service 'exposure'.

IMPLICATIONS

Research around DCRs/SIFs has used ecological, modelling, cross-sectional and cohort study designs. Further research could involve systematic inclusion of a control group of people who are eligible but do not access SIFs, validation of self-reported proportion of injections at SIFs or a stepped-wedge or a cluster trial comparing localities.

CONCLUSIONS

Methodologies appropriate for DCR/SIF evaluation have been established and can be readily replicated from the existing literature. Research on operational aspects, implementation and transferability is also warranted.

Overdose Risk and Client Characteristics Associated With the Injection of Buprenorphine at a Medically Supervised Injecting Center in Sydney, Australia

Background: Buprenorphine and buprenorphine/naloxone (BNX) were developed to improve the safety profile of opioid substitution treatment (OST) and reduce diversion and injection, yet continue to be injected, despite the risk of harm. Previous studies examining injection of these substances have relied on self-reported injection and overdose. Using data from the Uniting Medically Supervised Injecting Center (MSIC) in Sydney, this study aimed to assess the overdose risk associated with the use of buprenorphine and BNX and identify factors associated with injecting. Methods: Client data routinely collected from MSIC, a drug consumption room where clients can legally inject drugs under supervision, was used. Odds ratios (OR) to assess the risk of overdose and their associated 95% confidence intervals (95%CI) were calculated and compared to other substances. Univariate analysis using χ-square and multivariate logistic regressions were used to determine characteristics associated with buprenorphine and BNX injection. Results: Data from 1,020,782 injections by 15,832 individuals were analyzed. Risk of overdose was low for buprenorphine compared to other substances (OR 0.16; 95%CI: 0.07-0.19) and no overdoses occurred when BNX was injected. Injection of both buprenorphine and BNX was associated with male gender, homelessness, no income/reliance upon government payments, and prior imprisonment. Conclusions: Buprenorphine and BNX continue to be injected, albeit in small numbers. This is the first study to report on injection and overdose risk using direct observation, and has confirmed the lower overdose risk. MSIC clients who inject buprenorphine and BNX tend to be marginalized and may benefit from targeted harm reduction measures.

New synthetic opioids: Part of a new addiction landscape

Synthetic opioids (SO) are a major risk for public health across the world. These drugs can be divided into 2 categories, pharmaceutical and non-pharmaceutical fentanyls. A new generation of SO has emerged on the drug market since 2010. North America is currently facing an opioid epidemic of morbi-mortality, caused by over-prescription of opioids, illegally diverted prescribed medicines, the increasing use of heroin and the emergence of SO. Furthermore, this opioid crisis is also seen in Europe. SO are new psychoactive substances characterized by different feature such as easy availability on the Internet, low price, purity, legality, and lack of detection in laboratory tests. They have not been approved or are not recommended for human use. Opioid misuse is associated with somatic and psychiatric complications. For many substances, limited pharmacological information is available, increasing the risk of harmful adverse events. Health actors and the general population need to be clearly informed of the potential risks and consequences of the diffusion and use of SO.

Evaluation of a fentanyl drug checking service for clients of a supervised injection facility, Vancouver, Canada

BACKGROUND

British Columbia, Canada, is experiencing a public health emergency related to opioid overdoses driven by consumption of street drugs contaminated with illicitly manufactured fentanyl. This cross-sectional study evaluates a drug checking intervention for the clients of a supervised injection facility (SIF) in Vancouver.

METHODS

Insite is a facility offering supervised injection services in Vancouver's Downtown East Side, a community with high levels of injection drug use and associated harms, including overdose deaths. During July 7, 2016, to June 21, 2017, Insite clients were offered an opportunity to check their drugs for fentanyl using a test strip designed to test urine for fentanyl. Results of the drug check were recorded along with information including the substance checked, whether the client intended to dispose of the drug or reduce the dose and whether they experienced an overdose. Logistic regression models were constructed to assess the associations between drug checking results and dose reduction or drug disposal. Crude odds ratios (OR) and 95% confidence intervals (CI) were reported.

RESULTS

About 1% of the visits to Insite during the study resulted in a drug check. Out of 1411 drug checks conducted by clients, 1121 (79.8%) were positive for fentanyl. Although most tests were conducted post-consumption, following a positive pre-consumption drug check, 36.3% (n = 142) of participants reported planning to reduce their drug dose while only 11.4% (n = 50) planned to dispose of their drug. While the odds of intended dose reduction among those with a positive drug check was significantly higher than those with a negative result (OR = 9.36; 95% CI 4.25-20.65), no association was observed between drug check results and intended drug disposal (OR = 1.60; 95% CI 0.79-3.26). Among all participants, intended dose reduction was associated with significantly lower odds of overdose (OR = 0.41; 95% CI 0.18-0.89).

CONCLUSIONS

Although only a small proportion of visits resulted in a drug check, a high proportion (~ 80%) of the drugs checked were contaminated with fentanyl. Drug checking at harm reduction facilities such as SIFs might be a feasible intervention that could contribute to preventing overdoses in the context of the current overdose emergency.

[Interest of take-home naloxone for opioid overdose]

Over the course of these last decades, we observed a change on opioid use with the marketing of opiate maintenance treatment, an increase of opioids used for pain management and recent concerns have arisen around the use of synthetic opioid. The World Health Organization (WHO) reports around 70,000 people opioid overdose death each year. In France, according to the DRAMES program (fatalities in relation with abuse of licit or illicit drugs) of the French addictovigilance network, most of deaths are related to opioids overdose (especially methadone, following by heroin, buprenorphine and opioid used for pain management). Opioid overdose is treatable with naloxone, an opioid antagonist which rapidly reverses the effects of opioids. In recent years, a number of programs around the world have shown that it is feasible to provide naloxone to people likely to witness an opioid overdose. In 2014, the WHO published recommendations for this provision and the need to train users and their entourage in the management of opioid overdose. In this context, in July 2016, French drug agency has granted a temporary authorization for use of a naloxone nasal spray Nalscue^®. Because different opioids can be used and because each opioid has specific characteristics (pharmacodynamics, pharmacokinetics, galenic form…), the risk of overdose may differ from one opioid to another and it may be necessary, depending on the clinical context, to use larger and repeated doses of naloxone.

Fentanyl and heroin contained in seized illicit drugs and overdose-related deaths in British Columbia, Canada: An observational analysis

BACKGROUND

Due to the alarming rise in opioid-related overdose deaths, a public health emergency was declared in British Columbia (BC). In this study, we examined the relationship between illicit fentanyl and heroin found in seized drugs and illicit overdose deaths in BC.

METHODS

An observational cross-sectional survey was conducted using BC data from Health Canada's Drug Analysis Service, which analyzes drug samples seized by law enforcement agencies, and non-intentional illicit overdoses from the BC Coroner's Service, from 2000 to 2016. Initial scatter plots and subsequent multivariate regression analysis were performed to describe the potential relationship between seized illicit fentanyl samples and overdose deaths and to determine if this differed from seized heroin and overdose deaths. Fentanyl samples were analyzed for other drug content.

RESULTS

Fentanyl is increasingly being found combined with other opioid and non-opioid illicit drugs. Strong positive relationships were found between the number of seized fentanyl samples and total overdose deaths (R2 = 0.97) as well as between seized fentanyl and fentanyl-detected overdose deaths (R2 = 0.99). A positive association was found between the number of seized heroin samples and total overdose deaths (R2 = 0.78).

CONCLUSION

This research contributes to the expanding body of evidence implicating illicit fentanyl use (often combined with heroin or other substances) in overdose deaths in BC. Policy makers and healthcare providers are urged to implement drug treatment and harm reduction strategies for people at risk of overdose associated with current trends in illicit opioid use.

Intravenous fentanyl use among people who inject drugs in Australia

INTRODUCTION AND AIMS

There is a current epidemic of pharmaceutical opioid (PO) misuse, particularly fentanyl and fentanyl analogues, globally. Fentanyl is a highly potent synthetic opioid with rapid onset and significantly higher risk of overdose compared with other opioids. Contexts and correlates of fentanyl use among people who inject drugs (PWID) in Australia are under-researched.

DESIGN AND METHODS

The Australian Needle Syringe Program Survey is conducted annually. Consenting PWID complete a self-administered questionnaire and provide a capillary dried blood spot for human immunodeficiency virus and hepatitis C virus antibody testing. Bivariate and multivariate logistic regressions determined correlates of recent (last 6 months) fentanyl injection in 2014.

RESULTS

Recent fentanyl injection was reported by 8% (n = 193) of the total sample. Among the 848 PWID who recently injected POs, 23% injected fentanyl. Compared with PO injectors who had not injected fentanyl, those who had injected fentanyl were significantly more likely to identify as Indigenous Australian [adjusted odds ratio (AOR) 1.61; 95% confidence interval (CI) 1.04, 2.51; P = 0.034], inject daily or more frequently (AOR 1.92; 95% CI 1.30, 2.83; P = 0.005), inject in public (AOR 1.43; 95% CI 1.01, 2.02; P = 0.042) and to have overdosed in the past year (AOR 2.16; 95% CI 1.48, 3.13; P < 0.001), but were significantly less likely to receptively share syringes (AOR 0.56; 95% CI 0.36, 0.87; P = 0.010).

DISCUSSION AND CONCLUSIONS

Fentanyl injectors in Australia are significantly more likely to identify as Indigenous, report frequent injection, inject in public and experience overdose. Increased access to harm reduction interventions, including naloxone distribution, wheel filters and supervised injection facilities, are likely to benefit this population.