Time-Series Analysis of Fentanyl Concentration in the Unregulated Opioid Drug Supply in a Canadian Setting

Fentanyl, carfentanil and other fentanyl analogues in Canada's illicit opioid supply: A cross-sectional study

Background

Despite the increase in fentanyl-involved overdose deaths in Canada, there have been no national-level studies evaluating the proportion of illicit opioids containing fentanyl or fentanyl analogues in Canada.

Methods

This cross-sectional exploratory study characterized trends in fentanyl, carfentanil and other fentanyl analogues within opioids seized by law enforcement agencies in Canada from 2012 to 2022 and submitted to the Health Canada Drug Analysis Service (DAS). Analyses were stratified by province/region. Mann-Kandell tests were used to test for trends.

Results

A total of 157,616 samples containing any opioid ("opioid-containing samples") were submitted to the DAS from Canadian provinces between 2012 and 2022, of which 81,165 (51.5%) contained fentanyl or a fentanyl analogue. The percentage of opioid-containing samples that were positive for fentanyl or a fentanyl analogue increased from 3.0% (95% CI: 2.6-3.4%) in 2012-68.3% (67.7-68.9%) in 2022 (p < 0.001 for trend). The percentage of opioid-containing samples that were positive for fentanyl or a fentanyl analogue increased between 2012 and 2022 in all regions. In 2022, the percentage of samples containing fentanyl or an analogue followed an east-to-west gradient: 15.8% (13.3-18.6%) of samples in Atlantic Canada and 84.7% (83.6-85.7%) in British Columbia. Carfentanil was present in 4.9% (4.6-5.2%) of opioid-containing samples in Canada in 2022 and 19.7% (18.3-21.2%) of opioid-containing samples in Alberta.

Conclusions

The illicit opioid supply in Canada increasingly contains toxic synthetic opioids. As of 2022, important regional differences existed in the illicit opioid supply in Canada.

Beyond a spec: assessing heterogeneity in the unregulated opioid supply

BACKGROUND

Drug checking services aim to provide compositional information for the illicit drug supply and are being employed in public health responses to extreme rates of overdose associated with fentanyl within street opioids. The technologies used within these services range from basic qualitative tests, such as immunoassay test strips, to comprehensive quantitative analyses, such as mass spectrometry. In general, there is concern that heterogeneity of a drug mixture adds significant uncertainty when using drug checking results based on a small subsamples. The presence of hot spots of active drug components in this context is often termed the 'chocolate chip cookie effect'. Establishing the limitations of the service are essential for interpretation of the results.

METHODS

This study assesses the consequence of drug heterogeneity and sampling of consumer level opioid purchased in Victoria, British Columbia ( n = 21 , 50-100 mg each) on quantitative fentanyl results determined from testing with paper spray mass spectrometry.

RESULTS

Using descriptive statistics, such as relative standard deviation and interquartile range, the results demonstrate varied distributions of fentanyl concentrations within a single drug batch. However, the presence of hot spots, defined as outliers, were relatively rare.

CONCLUSIONS

This study found that the variability in fentanyl concentration from drug heterogeneity and sampling is greater than that attributed to the analytical technique. On a practical level, this provides data to help guide communication of limitations of drug checking services, supporting the aim of trust and transparency between services and people who use drugs. However, if drug checking services continue to be restricted from fully engaging with the reality of manufacturing, buying, selling, mixing and dosing practices, the accuracy, usefulness, and impact will always be limited.

Full Characterisation of Heroin Samples Using Infrared Spectroscopy and Multivariate Calibration

The analysis of heroin samples, before use in the protected environment of user centra, could be a supplementary service in the context of harm reduction. Infrared spectroscopy hyphenated with multivariate calibration could be a valuable asset in this context, and therefore 125 heroin samples were collected directly from users and analysed with classical chromatographic techniques. Further, Mid-Infrared spectra were collected for all samples, to be used in Partial Least Squares (PLS) modelling, in order to obtain qualitative and quantitative models based on real live samples. The approach showed that it was possible to identify and quantify heroin in the samples based on the collected spectral data and PLS modelling. These models were able to identify heroin correctly for 96% of the samples of the external test set with precision, specificity and sensitivity values of 100.0, 75.0 and 95.5%, respectively. For regression, a root mean squared error of prediction (RMSEP) of 0.04 was obtained, pointing at good predictive properties. Furthermore, during mass spectrometric screening, 10 different adulterants and impurities were encountered. Using the spectral data to model the presence of each of these resulted in performant models for seven of them. All models showed promising correct-classification rates (between 92 and 96%) and good values for sensitivity, specificity and precision. For codeine and morphine, the models were not satisfactory, probably due to the low concentration of these impurities as a consequence of acetylation. For methacetin, the approach failed.

A qualitative assessment of tablet injectable opioid agonist therapy (TiOAT) in rural and smaller urban British Columbia, Canada: Motivations and initial impacts

BACKGROUND

The evolving and unpredictable unregulated drug market has driven an unprecedented overdose crisis that requires effective intervention. Growing evidence suggests that novel opioid agonist treatments, such as tablet injectable opioid agonist therapy (TiOAT), have potential to prevent overdoses and other drug-related harms. More evidence is needed to characterize their utility in achieving these outcomes. The current article is an analysis of two TiOAT programs implemented in British Columbia, Canada, to assess impact on health and well-being, including overdose risk. Moreover, we explored participants' enrollment goals and if they were achieved.

METHODS

The study employed qualitative methods to evaluate the TiOAT program in two sites between October 2021 and April 2022. We developed a semi-structured interview tool to guide in depth interviews. All interviews (n = 32) took place on teleconference software or in person. Thematic analysis allowed for the emergence of themes associated with TiOAT participation.

RESULTS

Participants discussed various motivations for enrolling in TiOAT, which included gaining financial stability, reducing or eliminating drug use, addressing withdrawal symptoms, wanting to work, and improving social circumstances. An assessment of initial programmatic impacts revealed that many participant-identified motivators were achieved. Participants also reported fewer or no overdoses since starting TiOAT, and many reported switching from injecting to smoking drugs. Some challenges included adequate dosing as evidenced by ongoing withdrawal and pain. Some participants requested additional opioids, such as diacetylmorphine, to aid in reducing illicit drug use.

CONCLUSION

Participants described how TiOAT helped them to achieve many of their goals. Suggested programmatic improvements include enhanced patient-provider co-design with respect to dosing to address ongoing withdrawal and pain. As the unpredictability the unregulated drug market worsens, novel options, such as TiOAT, ought to be implemented broadly to reduce overdose events and improve quality of life for people who use drugs.

Fentanyl Concentration in Drug Checking Samples and Risk of Overdose Death in Vancouver, Canada

INTRODUCTION

The proliferation of fentanyl and its analogs in illegal, unregulated drug markets remains a major driver of the overdose crisis in North America. Drug checking services have been implemented as a harm reduction strategy to address the crisis. However, little is known about their potential utility as a mechanism for monitoring population-level risk of overdose stemming from changing fentanyl concentration in unregulated drugs over time. Therefore, this study assessed the relationship between median fentanyl concentration in expected opioid drug checking samples and the death rate due to illicit drug toxicity over time in Vancouver, Canada.

METHODS

Monthly population-based rates of death due to illicit drug toxicity were drawn from provincial coroner records. Monthly median percent fentanyl concentration was calculated using a validated quantification model from point-of-care Fourier-transform infrared spectra among expected opioid samples that tested positive for fentanyl at community drug checking services. A time-series analysis using generalized additive modeling was conducted to examine the association between monthly median fentanyl concentration and monthly death rate due to illicit drug toxicity, controlling for calendar month. Analyses were conducted in 2021-2022.

RESULTS

Between January 2019 and October 2020, 577 deaths due to illicit drug toxicity occurred in Vancouver, and the observed monthly rate ranged from 1.75 to 7.65 deaths per 100,000 population. A significant, positive association was observed between monthly median fentanyl concentration and monthly death rate due to illicit drug toxicity, adjusting for calendar month (chi-square=52.21, p<0.001).

CONCLUSIONS

Findings suggest a role for point-of-care drug checking as a tool for monitoring evolving overdose risk at the population level.

Motivators of and barriers to drug checking engagement in British Columbia, Canada: Findings from a cross-sectional study

OBJECTIVE

Responding to increasing rates of illicit drug toxicity mortality in British Columbia, regional health authorities introduced various types and models of drug checking services starting in 2016. Uptake has been gradual yet consistent, but motivators and barriers of service use have not been well-described.

METHODS

The British Columbia Harm Reduction Client Survey is a cross-sectional survey conducted at harm reduction sites across British Columbia. Data for the present findings were collected between March 2021 and January 2022. Participants (n = 537) were asked about their use of drug checking services and what prevented them from using available services. Responses were analyzed with descriptive statistics and multivariable logistic regression.

RESULTS

Of all participants, 519 (96.6 %) answered the survey question on drug checking with 144 (27.7 %) reporting having used services within six months. Participants highlighted barriers such as not knowing where to access services (21.0 %), or not having services in their area (10.0 %). Among people who did not report recent use of fentanyl, 49.6 % stated they would not use their drugs if they tested positive for fentanyl. Other harm reduction behaviors were positively associated with drug checking, such as use of overdose prevention sites (adjusted odds ratio [AOR]: 2.75, 95 % confidence interval [CI]: 1.65, 4.59) and having a naloxone kit (AOR: 2.67, 95 %CI: 1.14, 6.28). Receipt of opioid agonist therapy in the previous six months was also positively associated with drug checking (AOR: 1.72, 95 %CI: 1.05, 2.83).

DISCUSSION

Drug checking uptake remains low in British Columbia, however this study identified desire for services among participants, suggesting a need for expanded drug checking services. Behavioral change was reported among a high proportion of people who said they would not use their drugs if they tested positive for fentanyl, meaning that immunoassay strips alone have utility in the context of a pervasive fentanyl supply.

'Drug decriminalization' in Canada: a plea for a nuanced, evidence-informed, and realistic approach towards improved health outcomes

Canada has been home to an exceptional public health crisis of illicit (mainly synthetic opioid but increasingly other) drug deaths for numerous years. Despite extensive health-oriented interventions, this crisis remains acute and devastating. Earlier this year, the federal and British Columbia governments implemented the 'drug decriminalization initiative' (DDI) which exempts drug users from criminal enforcement of small amounts of personal drug possession; this has been promoted as a 'solution' for the drug-death crisis. This commentary examines and discusses that while decriminalization of drug use is fundamentally required to align drug policy with principles of health, evidence-based consideration of the drug death crisis' essential dynamics as well as enforcement realities substantially curtail the DDI's plausible prospects to significantly reduce the drug-fatality toll. Decriminalization efforts elsewhere ('Portugal model') are set in distinct ecologies and parameters, and not readily transferable to Canadian contexts. While the DDI has symbolic value for policy reform, for decriminalization to provide tangible benefits for drug users and public health, its scope and design require fundamental reconsideration and improvement. Meanwhile, given the principally causal role of toxic drug supply for the current drug-death epidemic, more effective health and life-saving measures-specifically involving 'safer supply'-need to be urgently implemented to alleviate this crisis.

Drug checking in the fentanyl era: Utilization and interest among people who inject drugs in San Diego, California

BACKGROUND

In North America, overdose rates have steeply risen over the past five years, largely due to the ubiquity of illicitly manufactured fentanyls in the drug supply. Drug checking services (DCS) represent a promising harm reduction strategy and characterizing experiences of use and interest among people who inject drugs (PWID) is a priority.

METHODS

Between February-October 2022, PWID participating in a cohort study in San Diego, CA and Tijuana, Mexico completed structured surveys including questions about DCS, socio-demographics and substance use behaviors. We used Poisson regression to assess factors associated with lifetime DCS use and characterized experiences with DCS and interest in free access to DCS.

RESULTS

Of 426 PWID, 72% were male, 59% Latinx, 79% were experiencing homelessness and 56% ever experienced a nonfatal overdose. One third had heard of DCS, of whom 57% had ever used them. Among the latter, most (98%) reported using fentanyl test strips (FTS) the last time they used DCS; 66% did so less than once per month. In the last six months, respondents used FTS to check methamphetamine (48%), heroin (30%) or fentanyl (29%). Relative to White/non-Latinx PWID, those who were non-White/Latinx were significantly less likely to have used DCS [adjusted risk ratio (aRR): 0.22; 95% CI: 0.10, 0.47), as were PWID experiencing homelessness (aRR:0.45; 95% CI: 0.28, 0.72). However, a significant interaction indicated that non-White/Latinx syringe service program (SSP) clients were more likely to have used DCS than non-SSP clients (aRR: 2.79; CI: 1.09, 7.2). Among all PWID, 44% expressed interest in free access to FTS, while 84% (of 196 PWID) expressed interest in advanced spectrometry DCS to identify and quantify multiple substances.

CONCLUSIONS

Our findings highlight low rates of DCS awareness and utilization, inequities by race/ethnicity and housing situation, high interest in advanced spectrometry DCS versus FTS, and the potential role of SSPs in improving access to DCS, especially among racial/ethnic minorities.

Development of a neural network model to predict the presence of fentanyl in community drug samples

INTRODUCTION

Increasingly, Fourier-transform infrared (FTIR) spectroscopy is being used as a harm reduction tool to provide people who use drugs real-time information about the contents of their substances. However, FTIR spectroscopy has been shown to have a high detection limit for fentanyl and interpretation of results by a technician can be subjective. This poses concern, given that some synthetic opioids can produce serious toxicity at sub-detectable levels. The objective of this study was to develop a neural network model to identify fentanyl and related analogues more accurately in drug samples compared to traditional analysis by technicians.

METHODS

Data were drawn from samples analyzed point-of-care using combination FTIR spectroscopy and fentanyl immunoassay strips in British Columbia between August 2018 and January 2021. We developed neural network models to predict the presence of fentanyl based on FTIR data. The final model was validated against the results from immunoassay strips. Prediction performance was assessed using F1 score, accuracy, and area under the receiver-operating characteristic curve (AUROC), and was compared to results obtained from analysis by technicians.

RESULTS

A total of 12,684 samples were included. The neural network model outperformed results from those analyzed by technicians, with an F1 score of 96.4% and an accuracy of 96.4%, compared to 78.4% and 82.4% with a technician, respectively. The AUROC of the model was 99.0%. Fentanyl positive samples correctly detected by the model but not by the technician were typically those with low fentanyl concentrations (median: 2.3% quantity by weight; quartile 1-3: 0.0%-4.6%).

DISCUSSION

Neural network models can accurately predict the presence of fentanyl and related analogues using FTIR data, including samples with low fentanyl concentrations. Integrating this tool within drug checking services utilizing FTIR spectroscopy has the potential to improve decision making to reduce the risk of overdose and other negative health outcomes.

Evaluation of fentanyl immunoassay test strips for rapid in-situ detection of fentanyl and fentanyl analogs in seized samples and alternative matrices

BACKGROUND

Ion mobility spectrometry is used for the rapid detection of drugs at points of security but are unable to differentiate some drugs leading to the instrument alarming for a drug not present in the sample. This can be particularly problematic for samples that alarm for fentanyl. In this study, fentanyl immunoassay strips were evaluated for use as a secondary test for fentanyl, including for the testing of alternative matrices, such as powders, e-liquids, and infused papers and textiles.

METHODS

The limit of detection of fentanyl immunoassay strips was examined along with their selectivity to 18 fentanyl analogsand 72 other drugs and cutting agents. The effectiveness of the test strips at the detection of fentanyl in the presence of other drugs was examined by testing a series of concentrations of fentanyl in solution in combination with other drugs. The testing of alternative matrices was explored with laboratory prepared samples through sampling with cotton buds and extraction in water.

RESULTS

The fentanyl immunoassay strips detected fentanyl at concentrations of 45 ng/mL and reacted with 16 of 18 tested fentanyl analogs with carfentanil and norfentanyl being the only analogs to not react. There was no reactivity with other drugs or cutting agents. The effectiveness of the fentanyl test strips was not reduced when fentanyl was mixed with other drugs. Fentanyl was successfully detected with high sensitivity in all alternative matrices.

CONCLUSION

The fentanyl immunoassay strips were found to be an effective secondary test for fentanyl and at least 16 fentanyl analogs in seized drug samples, including when mixed with other drugs. The effectiveness of the sampling methods for alternative matrices should be further evaluated using fentanyl and fentanyl analog casework samples. The use of this method by law enforcement and other agencies should be examined to assess its effectiveness and ease of use in operational settings.

Provider experiences with relaxing restrictions on take-home medications for opioid use disorder during the COVID-19 pandemic: A qualitative systematic review

BACKGROUND

Historical restrictions on take-home medications for opioid use disorder have generated considerable debate. The COVID-19 pandemic shifted the perceived risks and benefits of daily clinic attendance and led to widespread policy reform, creating an unprecedented opportunity to explore the impact of more flexible prescribing. We conducted a qualitative systematic review to synthesize the evidence on providers' experiences with relaxing restrictions on take-home doses of medications prescribed for opioid use disorder during the COVID-19 pandemic.

METHODS

The protocol for this systematic review was registered in PROSPERO (CRD42022360589; https://www.crd.york.ac.uk/prospero/). From Sept.-Nov. 2022, we searched Medline, Embase, CINAHL, PsycInfo, Web of Science, the Cochrane Register of Controlled Trials, and the grey literature from 2020 onward. Studies were eligible for inclusion if they used qualitative methods to investigate providers' experiences with relaxed restrictions on take-home medications for opioid use disorder during the COVID-19 pandemic. We appraised study quality using the CASP qualitative checklist and used thematic synthesis and GRADE-CERQual to synthesize the results.

RESULTS

We retrieved 13 articles representing 11 studies. Six were conducted in the United States and most focused on changes to methadone treatment. Providers' experiences with increased flexibilities around take-homes were broadly positive, despite widespread initial concern over client safety and the potential for medication misuse. For a small number of providers, concerns about diversion were a specific manifestation of more general unease with loss of control over clients and the treatment process. Most providers appreciated increased flexibilities and described them as enabling more individualized, person-centered care.

CONCLUSION

Our findings support the continuation of flexibilities around take-homes and demonstrate that regulations and policies that reduce flexibility around take-homes conflict with person-centered approaches to care. Stronger guidance and support from professional regulatory agencies may help increase uptake of flexibilities around take-homes.

Correlates of recent overdose among people who inject drugs in the San Diego/Tijuana border region

BACKGROUND

Along the Mexico-US border, illicitly manufactured fentanyls (fentanyl) have been detected in other illicit drugs, including street opioid formulations known as 'china white.' We studied correlates of recent overdose among people who inject drugs (PWID), focusing on the risk of knowlingly or unknowingly using fentanyl in china white.

METHODS

From October 2020 - September, 2021 we surveyed participants in San Diego, California and Tijuana, Mexico and employed Poisson regression to identify correlates of recent overdose.

RESULTS

Of 612 PWID, most were male (74.0 %), Latinx (71.9 %), US residents (67.0 %). Mean age was 43 years. In the last six months, 15.8 % experienced overdose, 31.0 % knowingly used fentanyl and 11.1 % used china white, of whom 77.9 % did not think it contained fentanyl. After controlling for sex and race, factors independently associated with risk of overdose included knowingly using fentanyl, using china white and not believing it contained fentanyl, recent drug rehabilitation, being stopped/arrested by police, and homelessness. Further, PWID who believed china white contained fentanyl were less likely to use it.

CONCLUSIONS

Both intentional fentanyl use and unintentional exposure to fentanyl via china white were associated with overdose risk; however, PWID who believed china white contained fentanyl were less likely to use it. These data suggest that advanced drug checking systems should be implemented to empower PWID to avoid dangerous street formulations or to plan their drug use knowing its contents. Other overdose risk factors such as decreased tolerance following drug treatment, police interactions, and homelessness also require urgent intervention.

Implementation of Safe Supply Alternatives During Intersecting COVID-19 and Overdose Health Emergencies in British Columbia, Canada, 2021

Objectives. To explore the implementation and effectiveness of the British Columbia, Canada, risk mitigation guidelines among people who use drugs, focusing on how experiences with the illicit drug supply shaped motivations to seek prescription alternatives and the subsequent impacts on overdose vulnerability. Methods. From February to July 2021, we conducted qualitative interviews with 40 people who use drugs in British Columbia, Canada, and who accessed prescription opioids or stimulants under the risk mitigation guidelines. Results. COVID-19 disrupted British Columbia's illicit drug market. Concerns about overdose because of drug supply changes, and deepening socioeconomic marginalization, motivated participants to access no-cost prescription alternatives. Reliable access to prescription alternatives addressed overdose vulnerability by reducing engagement with the illicit drug market while allowing greater agency over drug use. Because prescriptions were primarily intended to manage withdrawal, participants supplemented with illicit drugs to experience enjoyment and manage pain. Conclusions. Providing prescription alternatives to illicit drugs is a critical harm reduction approach that reduces exposure to an increasingly toxic drug supply, yet further optimizations are needed. (Am J Public Health. 2022;112(S2):S151-S158. https://doi.org/10.2105/AJPH.2021.306692).

Drug checking services for people who use drugs: a systematic review

BACKGROUND AND AIMS

Drug checking services provide people who use drugs with chemical analysis results of their drug samples while simultaneously monitoring the unregulated drug market. We sought to identify and synthesize literature on the following domains: (a) the influence of drug checking services on the behaviour of people who use drugs; (b) monitoring of drug markets by drug checking services; and (c) outcomes related to models of drug checking services.

METHODS

Systematic review. A systematic literature search was conducted in MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PsycINFO, Scopus, Web of Science and Dissertations and Theses Global. Eligible studies were peer-reviewed articles and conference abstracts or grey literature, published in any language since 1990 and including original data on the domains. We assessed risk of bias for quantitative peer-reviewed articles reporting on behaviour or models of drug checking services using National Institutes of Health tools.

RESULTS

We screened 2463 titles and abstracts and 156 full texts, with 90 studies meeting inclusion criteria. Most (n = 65, 72.2%) were from Europe and used cross-sectional designs (n = 79, 87.7%). Monitoring of drug markets by drug checking services (n = 63, 70%) was the most reported domain, followed by the influence of drug checking services on behaviour (n = 31, 34.4%), including intent to use, actual use and disposal of the drug, and outcomes related to models of drug checking services (n = 17, 18.9%). The most common outcome measures were detection of unexpected substances (n = 50, 55.6%), expected substances (n = 44, 48.9%), new psychoactive substances (n = 40, 44.4%) and drugs of concern (n = 32, 36.5%) by drug checking services.

CONCLUSIONS

Drug checking services appear to influence behavioural intentions and the behaviour of people who use drugs, particularly when results from drug checking services are unexpected or drugs of concern. Monitoring of drug markets by drug checking services is well established in Europe, and increasingly in North America. Concerns about drug contents and negative health consequences facilitate the use of drug checking services; lack of concern; trust in drug sellers; lack of accessibility of drug checking services; and legal and privacy concerns are barriers to use.