Comparing injecting and non-injecting illicit opioid users in a multisite Canadian sample (OPICAN Cohort)

Relationship between opioid cross-tolerance during buprenorphine stabilization and return to opioid use during buprenorphine dose tapering

RATIONALE

Opioid injection drug use (IDU) has been linked to a more severe pattern of use (e.g. tolerance, overdose risk) and shorter retention in treatment, which may undermine abstinence attempts.

OBJECTIVES

This secondary data analysis of four human laboratory studies investigated whether current opioid IDU modulates subjective abuse liability responses to high-dose hydromorphone during intermediate-dose buprenorphine stabilization (designed to suppress withdrawal but allow surmountable agonist effects), and whether hydromorphone response magnitude predicts latency of return to opioid use during buprenorphine dose-tapering.

METHODS

Regular heroin users not currently seeking treatment (n = 54; 29 current injectors, 25 non-injectors) were stabilized on 8-mg/day sublingual buprenorphine and assessed for subjective responses (e.g. 'liking', craving) to hydromorphone 24-mg intramuscular challenge (administered 16-hr post-buprenorphine) under randomized, double-blinded, controlled conditions. A subgroup (n = 35) subsequently completed a standardized 3-week outpatient buprenorphine dose-taper, paired with opioid-abstinent contingent reinforcement, and were assessed for return to opioid use based on thrice-weekly urinalysis and self-report.

RESULTS

During buprenorphine stabilization, IDU reported lower 'liking' of buprenorphine and post-hydromorphone peak 'liking', 'good effect' and 'high' compared to non-IDU. Less hydromorphone peak increase-from-baseline in 'liking' (which correlated with less hydromorphone-induced craving suppression) predicted significantly faster return to opioid use during buprenorphine dose-tapering.

CONCLUSIONS

In these buprenorphine-stabilized regular heroin users, IDU is associated with attenuated 'liking' response (more cross-tolerance) to buprenorphine and to high-dose hydromorphone challenge and, in turn, this cross-tolerance (but not IDU) predicts faster return to opioid use. Further research should examine mechanisms that link cross-tolerance to treatment response.

Changes in injecting versus smoking heroin, fentanyl, and methamphetamine among people who inject drugs in San Diego, California, 2020-2023

BACKGROUND

Amidst an increasingly toxic drug supply in North America, people who inject drugs may be transitioning to smoking them. We aimed to assess changes in injecting and smoking opioids and methamphetamine among a cohort of people who inject drugs from San Diego, California.

METHODS

Over five six-month periods spanning October 2020-April 2023, we assessed prevalence of injecting and smoking opioids or methamphetamine and whether participants used these drugs more frequently by smoking than injecting. Multivariable Poisson regression via generalized estimating equations was used to examine time trends.

RESULTS

Of 362 participants, median age was 40 years; a minority were female (29%), Hispanic/Latinx/Mexican (45%), and housed (33%). Among this cohort, of whom 100% injected (and 84% injected and smoked) in period one (October 2020-April 2021), by period five (November 2022-April 2023), 34% only smoked, 59% injected and smoked, and 7% only injected. By period five, the adjusted relative risk (aRR) of injecting opioids was 0.41 (95% Confidence Interval [CI]: 0.33, 0.51) and the aRR for injecting methamphetamine was 0.50 (95% CI: 0.39, 0.63) compared to period one. Risks for smoking fentanyl rose significantly during period three (aRR=1.44, 95% CI: 1.06, 1.94), four (aRR=1.65, 95% CI: 1.24, 2.20) and five (aRR=1.90, 95% CI: 1.43, 2.53) compared to period one. Risks for smoking heroin and methamphetamine more frequently than injecting these drugs increased across all periods.

CONCLUSIONS

Opioid and methamphetamine injection declined precipitously, with notable increases in smoking these drugs. Research is needed to understand the health consequences of these trends.

Comorbid Affective and Substance Use Disorders of Medicaid/Medicare Beneficiaries at an Opioid Treatment Program Serving Small Urban and Rural Communities

Objectives

Identify rates and correlates of comorbid affective and substance use disorders among an understudied population, Medicaid/Medicare beneficiaries receiving care at an opioid treatment program serving patients from small urban and rural areas. Examine whether past-year non-medical opioid use status differentiates comorbidity status.

Methods

A cross-sectional, venue-based design was used to recruit a convenience sample of patients treated with methadone for opioid use disorder. Measures were assessed across three domains: (1) demographic characteristics, (2) opioid use characteristics, and (3) comorbid disorders. Brief validated screeners categorized probable comorbid disorders. Bivariate analyses examined correlates of comorbid disorders and determined variable selection for multivariable analyses.

Results

In this sample (N = 210; mean age = 38.5 years; female = 62.2%; Non-Hispanic White race/ethnicity = 86.1%), comorbid disorders were common. Rates were as follows: current anxiety (48.1%), depression (41.1%), and PTSD (33.7%), and past-year stimulant (27.6%), marijuana (19.0%), alcohol (14.9%), and sedative (7.6%). In bivariate analyses, past-year non-medical opioid use and a greater accumulation of opioid use consequences were associated with most disorders. When including demographic and opioid use characteristics in multivariable analyses, past-year non-medical opioid use was associated with anxiety, PTSD, stimulant use disorder, and sedative use disorder.

Conclusions

Few studies have investigated comorbid disorders among this understudied population. This analysis highlights a high burden, especially for affective disorders. Our findings demonstrate that routine, ongoing assessment of non-medical opioid use may be a promising and feasible strategy to detect patients needing integrated care. Future research should investigate whether changes to assessment protocols at opioid treatment programs in small urban and rural settings facilitate care coordination.

Treatment Outcomes Among Black Adults Receiving Medication for Opioid Use Disorder

Largely due to structural racism, Black people with substance use disorder have worse outcomes than their White counterparts. The opioid epidemic has amplified these racial disparities. Little is known about strengths that buffer against the systemic issues that disproportionately impact Black adults with opioid use disorder (OUD), particularly those receiving buprenorphine for OUD. The objectives of this study are to (1) assess psychosocial and clinical predictors of OUD outcomes and (2) explore differences in OUD outcomes by gender among a sample of Black adults receiving buprenorphine. This is a secondary data analysis of a cross-sectional survey and medical record review with a convenience sample recruited from an addiction medicine clinic. Analyses included Black participants who provided at least one urine drug test during the study period (n = 98). Prospective 6-month OUD outcomes (treatment retention, substance use recurrence, and buprenorphine continuation) were abstracted from the medical record. Univariate analyses explored differences by gender. Multivariate regressions assessed predictors of OUD outcomes. Participants were 53% women and middle-aged (47 ± 12 years). The majority (59%) had been in treatment for at least 1 year at study enrollment. Substance use recurrence was common, but many individuals remained in treatment. OUD outcomes did not differ by gender. Older age and absence of injection opioid use history were significant predictors of treatment retention and buprenorphine continuation. When provided access to high-quality treatment, Black adults with OUD demonstrate positive outcomes. Addressing structural racism and developing culturally informed treatment interventions are necessary to improve access to high-quality care for this community.

The Risk Environment for Adopting and Continuing Injecting Drug Use: A Qualitative Study in Uyo, Nigeria

Background: The bulk of research on adoption of injecting is from Europe and America, despite the existence of syndemics of drug injecting, HIV, and viral hepatitis globally. Objectives: This study explores adoption and continuation of injecting drug use. Methods: The study draws on in-depth interviews with 41 (n = 41) current male and female people who inject drugs recruited via snow-ball sampling in Uyo, Nigeria. A thematic and descriptive analysis was undertaken informed by the risk environment framework and focused on accounts of the factors influencing the process. Results: Accounts emphasized injecting adoption and continuation as a process influenced by individual, social, and structural factors within the risk environment, including concerns for pleasure/efficiency, prestige, exposure to/support for injecting within peer and sexual relationships, availability and purity of drugs, and dependence and increased cost of drug use. Conclusions/implications: Findings highlight the need to prevent adoption of injecting, reduce prevalence of injecting, and promote safe injecting through multi-level interventions, including peer-driven education, drug treatment services, needle and syringe distribution, oral drug substitution, and law enforcement targeting drug suppliers. The need for equivalent pleasure with minimal risk points to the strategic importance of peer interactions for inculcating new understandings of drug use and pleasure.

Injection opioid use as a predictor of treatment outcomes among methadone-maintained opioid-dependent patients

BACKGROUND

Injection opioid use is associated with more severe health and psychosocial consequences relative to non-injection use, but few studies have examined whether injection use is associated with methadone maintenance treatment outcomes. The present study examined differential MMT outcomes among opioid injectors and non-injectors.

METHODS

Data were extracted from the clinic charts of opioid-dependent MMT patients (N = 290; n = 115 injectors) enrolled in a university-affiliated, urban MMT clinic. Injection status was examined as a predictor of short- (3-month opioid, cocaine, benzodiazepine and cannabis urine drug screens) and long- (days retained in treatment) term MMT outcomes.

RESULTS

Bivariate analyses revealed injection users were less likely to be African American and to have completed high school, were more likely to have started heroin use before age 21, to report having hepatitis C, to report a baseline cocaine use disorder, and had higher methadone doses at 3-months into treatment. Injection status significantly predicted a greater proportion of cocaine-positive urine drug screens in the first 3 months of treatment, but did not significantly predict opioid, benzodiazepine or cannabis drug screens, or length of treatment retention.

CONCLUSION

This is one of a handful of studies to examine injection status as a predictor of MMT outcomes. Injection status is associated with cocaine use early in treatment, which has implications for the focus of treatment.

Electronic Health Record-Based Screening for Substance Abuse

Existing methods of screening for substance abuse (standardized questionnaires or clinician's simply asking) have proven difficult to initiate and maintain in primary care settings. This article reports on how predictive modeling can be used to screen for substance abuse using extant data in electronic health records (EHRs). We relied on data available through Veterans Affairs Informatics and Computing Infrastructure (VINCI) for the years 2006 through 2016. We focused on 4,681,809 veterans who had at least two primary care visits; 829,827 of whom had a hospitalization. Data included 699 million outpatient and 17 million inpatient records. The dependent variable was substance abuse as identified from 89 diagnostic codes using the Agency for Healthcare Quality and Research classification of diseases. In addition, we included the diagnostic codes used for identification of prescription abuse. The independent variables were 10,292 inpatient and 13,512 outpatient diagnoses, plus 71 dummy variables measuring age at different years between 20 and 90 years. A modified naive Bayes model was used to aggregate the risk across predictors. The accuracy of the predictions was examined using area under the receiver operating characteristic (AROC) curve in 20% of data, randomly set aside for the evaluation. Many physical/mental illnesses were associated with substance abuse. These associations supported findings reported in the literature regarding the impact of substance abuse on various diseases and vice versa. In randomly set-aside validation data, the model accurately predicted substance abuse for inpatient (AROC = 0.884), outpatient (AROC = 0.825), and combined inpatient and outpatient (AROC = 0.840) data. If one excludes information available after substance abuse is known, the cross-validated AROC remained high, 0.822 for inpatient and 0.817 for outpatient data. Data within EHRs can be used to detect existing or predict potential future substance abuse.

The relationship between initial route of heroin administration and speed of transition to daily heroin use

INTRODUCTION AND AIMS

The effect of heroin administration route on speed of transition to regular use is unknown. This paper aims to determine whether the speed of transition from initiation of heroin use to daily heroin use differs by route of administration (injecting, chasing/inhaling or snorting).

DESIGN AND METHODS

Privileged access interviewer survey of purposively selected sample of 395 current people who use heroin (both in and not in treatment) in London, UK (historical sample from 1991). Data on age and year of initiation, time from initiation to daily use and routes of administration were collected by means of a structured questionnaire. Generalised ordered logistic models were used to test the relationship between route of initial administration of heroin and speed of transition to daily heroin use. Analyses were adjusted for gender, ethnicity, daily use of other drug(s) at time of initiation, year of initiation and treatment status at interview.

RESULTS

After adjustment, participants whose initial administration route was injecting had a 4.71 (95% confidence interval 1.34-16.5) increase in likelihood of progressing to daily use within 1-3 weeks of initiation, compared to those whose initial administration route was non-injecting.

DISCUSSION AND CONCLUSIONS

The speed of transition from first use to daily heroin use is faster if the individual injects heroin at initiation of use. Those who initiate heroin use through injecting have a shorter time frame for intervention before drug use escalation. [Hines LA, Lynskey M, Morley KI, Griffiths P, Gossop M, Powis B, Strang J. The relationship between initial route of heroin administration and speed of transition to daily heroin use. Drug Alcohol Rev 2017;00:000-000].

Peer-engagement and its role in reducing the risky behavior among crack and methamphetamine smokers of the Downtown Eastside community of Vancouver, Canada

Background

The role of peers (former or current drug users) in reducing risky behavior within methamphetamine and crack smokers has not been well described or researched. The current study not only explores the role of peers in reducing risk factors for morbidity within the illicit drug smoking population in the Downtown Eastside (DTES) community of Vancouver but it also investigates the changes in the nature of drug use after the closure of an unsanctioned smoking facility.

Methods

The data pertain to qualitative interviews with 10 peers and 10 illicit drug smokers. The semi-structured interviews were conducted through community-based research, and the digital transcripts were analyzed via NVivo 10 software.

Results

The results indicate that peers (former and current drug users who are employed as educators) are instrumental in transferring risk reduction knowledge within crack and methamphetamine smokers. For example, these peers have been able to teach users about the risk of sharing pipes, using brillo, and using public drug. Furthermore, the Vancouver Area Network of Drug Users provides employment for crack and methamphetamine users in Vancouver who tend to have scarce sources of employment. However, since the closure of the unsanctioned inhalation facility, there has been significantly more public drug use and pipe sharing in the vicinity of the facility, placing drug smokers at significant risk of arrest, violence, and blood-borne infections.

Conclusions

The current study recommends expanding the harm reduction peer network for people who smoke illicit drugs in the DTES community of Vancouver who have historically been underserved.

Worldwide Prevalence and Trends in Unintentional Drug Overdose: A Systematic Review of the Literature

BACKGROUND

Drug overdose is an important, yet an inadequately understood, public health problem. Global attention to unintentional drug overdose has been limited by comparison with the scope of the problem. There has been a substantial increase in drug overdose incidence and prevalence in several countries worldwide over the past decade, contributing to both increased costs and mortality.

OBJECTIVES

The aim of this study was to systematically synthesize the peer-reviewed literature to document the global epidemiological profile of unintentional drug overdoses and the prevalence, time trends, mortality rates, and correlates of drug overdoses. We searched different combinations of Medical Subject Headings (MeSH) terms in PubMed for articles published from 1980 until July 2013, and we organized these results in tabular spreadsheets and compared them. We restricted the search to English-language articles that deal with unintentional overdose, focusing on 1 or more of the following key constructs: prevalence, time trends, mortality rates, and correlates. The term "overdose" as a MeSH major topic yielded 1076 publications. In addition, we searched the following combinations of nonmajor MeSH terms: "street drugs" and "overdose" yielded 180, "death" and "overdose" yielded 114, and "poisoning" and "drug users" yielded 17. There was some overlap among the searches. Based on the search and inclusion and exclusion criteria, we selected a total of 169 relevant articles for this article based on a close review of abstracts.

RESULTS

We found wide variability in lifetime prevalence of experiencing a nonfatal overdose or witnessing an overdose, and in mortality rates attributable to overdose. Lifetime prevalence of witnessed overdose among drug users (n = 17 samples) ranged from 50% to 96%, with a mean of 73.3%, a median of 70%, and a standard deviation of 14.1%. Lifetime prevalence of drug users personally experiencing a nonfatal overdose (n = 27 samples), ranged from 16.6% to 68.0% with a mean of 45.4%, a median of 47%, and a standard deviation of 14.4%. Population-based crude overdose mortality rates (n = 28 samples) ranged from 0.04 to 46.6 per 100 000 person-years. This range is likely attributable to the diversity in regions, time periods, and samples. Most studies on longitudinal trends of overdose death rates or overdose-related hospitalization rates showed increases in overdose death rates and in overdose-related hospitalization rates across time, which have led to peaks in these rates at the present time. An overall trend of increasing deaths from prescription opioid use and decreasing deaths from illicit drug use in the past several years has been noted across most of the literature. With the increase in prescription opioid overdose deaths, drug overdose is not just an urban problem: rural areas have seen an important increase in overdose deaths. Lastly, cocaine, prescription opioids, and heroin are the drugs most commonly associated with unintentional drug overdoses worldwide and the demographic and psychiatric correlates associated with unintentional drug overdoses are similar globally.

CONCLUSIONS

There is a need to invest in research to understand the distinct determinants of prescription drug overdose worldwide. Several other countries need to collect in a systematic and continuous fashion such data on sales of prescription opioids and other prescription drugs, nonmedical use of prescription drugs, and hospitalization secondary to overdoses on prescription drugs. The sparse evidence on the environmental determinants of overdose suggests a need for research that will inform the types of environmental interventions we can use to prevent drug overdose. Methodological issues for future studies include enhancing data collection methods on unintentional fatal and nonfatal overdoses, and collecting more detailed information on drug use history, source of drug use (for prescription drugs), and demographic and psychiatric history characteristics of the individual who overdosed.

Key Data Gaps Regarding the Public Health Issues Associated with Opioid Analgesics

Most pharmaceutical opioids are used to treat pain, and they have been demonstrated to be effective medications for many. Their abuse and misuse pose significant public health concerns in the USA. Research has provided much insight into the prevalence, scope, and drivers of opioid abuse, but a holistic understanding is limited by a lack of available data regarding key aspects of this public health problem. Twelve data gaps were revealed during the creation of a systems-level computer model of medical use, diversion, nonmedical use, and the adverse outcomes associated with opioid analgesics in the USA. Data specific to these gaps would enhance the validity and real-world applications of systems-level models of this public health problem and would increase understanding of the complex system in which use and abuse occur. This paper provides an overview of these gaps, argues for the importance of closing them, and provides specific recommendations for future data collection efforts.

Screening and Treatment for Alcohol, Tobacco and Opioid Use Disorders: A Survey of Family Physicians across Ontario

INTRODUCTION

As a primary point of contact within the health care system, family physicians are able to play a vital role in identifying individuals with substance use disorders and connecting them to the appropriate treatment. However, there is very little data available on whether family physicians are actively screening for and treating substance use disorders. The objective of the current survey was to assess whether family physicians in Ontario are screening for alcohol, opioid and tobacco use disorders, using validated tools and providing treatment.

METHODS

An online survey consisting of a series of 38 primarily close-ended questions was circulated to family physicians in Ontario. Rates of screening for alcohol, opioid and tobacco dependence, use of validated tools for screening, providing treatment for dependent individuals and the current barriers to the prescription of pharmacotherapies for these drug dependences were assessed.

RESULTS

The use of validated screening tools was limited for all three substances. Screening by family physicians for the substance use disorders among adolescents was much lower than screening among adults. Pharmacotherapy was more commonly used as an intervention for tobacco dependence than for alcohol and opioid dependence. This was explained by the lack of knowledge among family physicians on the pharmacotherapies for alcohol and opioid dependence.

CONCLUSIONS

Findings from the current study suggest there is a need for family physicians to integrate screening for substance use disorders using validated tools into their standard medical practice. Furthermore, there is a need for increased knowledge on pharmacotherapies for alcohol and opioid use disorders. It is important to note that the low response rate is a major limitation to this study. One possible reason for this low response rate may be a lack of interest and awareness among family physicians on the importance of screening and treatment of substance use disorders in Ontario.

A cost-benefit/cost-effectiveness analysis of an unsanctioned supervised smoking facility in the Downtown Eastside of Vancouver, Canada

BACKGROUND

Smoking crack involves the risk of transmitting diseases such as HIV and hepatitis C (HCV). The current study determines whether the formerly unsanctioned supervised smoking facility (SSF)-operated by the grassroot organization, Vancouver Area Network of Drug Users (VANDU) for the last few years-costs less than the costs incurred for health-care services as a direct consequence of not having such a program in Vancouver, Canada.

METHODS

The data pertaining to the attendance at the SSF was gathered in 2012-2013 by VANDU. By relying on this data, a mathematical model was employed to estimate the number of HCV infections prevented by the former facility in Vancouver's Downtown Eastside (DTES).

RESULTS

The DTES SSF's benefit-cost ratio was conservatively estimated at 12.1:1 due to its low operating cost. The study used 70% and 90% initial pipe-sharing rates for sensitivity analysis. At 80% sharing rate, the marginal HCV cases prevented were determined to be 55 cases. Moreover, at 80% sharing rate, the marginal cost-effectiveness ratio ranges from $1,705 to $97,203. The results from both the baseline and sensitivity analysis demonstrated that the establishment of the SSF by VANDU on average had annually saved CAD$1.8 million dollars in taxpayer's money.

CONCLUSIONS

Funding SSFs in Vancouver is an efficient and effective use of financial resources in the public health domain; therefore, Vancouver Coastal Health should actively participate in their establishment in order to reduce HCV and other blood-borne infections such as HIV within the non-injecting drug users.

Differences in sociodemographic, drug use and health characteristics between never, former and current injecting, problematic hard-drug users in the Netherlands

Background

Injecting drug users are at increased risk for harmful effects compared to non-injecting drug users. Some studies have focused on differences in characteristics between these two groups (e.g., housing, overall health). However, no study has investigated the specific Dutch situation which in the last years has seen a decrease in homelessness among problematic hard-drug users and an increasing focus on physical health in low-threshold addiction care. The purpose of this study was to determine differences in sociodemographic, drug use and health characteristics between never-injecting (NIDUs), former-injecting (FIDUs) and current-injecting drug users (IDUs) and describe injecting practices.

Methods

A total of 202 problematic hard-drug users (NIDU = 64; FIDU = 76; IDU = 62) were recruited from 22 low-threshold care facilities, including drug consumption rooms, methadone maintenance treatment, heroin-assisted therapy, day shelter and/or night shelter, supported housing and day activity centres. Data were collected on-site through structured face-to-face interviews.

Results

Results indicate that IDUs represented a separate group of problematic hard-drug users, with distinct sociodemographic and drug use characteristics. Overall, IDUs appeared to be the group with least favourable characteristics (unstable housing/homelessness, illegal activities, polydrug use) and NIDUs appeared to have the most favourable characteristics (stable housing, help with debts, less polydrug use). The FIDU group lies somewhere in between. The three groups did not differ significantly in terms of health. Regarding injecting practices, results showed that majority of IDUs had injected drugs for over 10 years and IDUs injected heroin, cocaine, amphetamine and/or methadone in the past 6 months. Sharing syringes was not common. A quarter reported public injecting.

Conclusions

Unstable housing and homelessness are related to (former) injecting drug use, and stable housing is related to never-injecting drug use. Our study suggests that the number of ‘new’ IDUs is low. However, public injecting among IDUs is not uncommon and is associated with unstable housing. This emphasizes the potential of housing projects as a component of harm reduction measures. Therefore, prevention of (risks associated with) injecting drug use and supported housing programmes for problematic hard-drug users deserve the continuous attention of policymakers and professionals in low-threshold addiction care.

Evidence of HIV epidemics among non-injecting drug users in Iran: a systematic review

AIMS

In Iran, injecting drug users have been recognized as a high-risk group for HIV/AIDS for years. However, evidence of HIV epidemics in non-injecting drug users (non-IDUs) has also been found in recent years. The aim of this systematic review was to determine the prevalence of HIV in non-IDUs in Iran.

METHODS

International and regional databanks, including Pubmed, ISI, CINAHL, ASCI and IMEMR, as well as domestic databanks such as IranPsych, IranMedex SID and research reports were searched, and extensive personal contacts were made. All studies with HIV testing conducted between 1998 and 2007, which included non-IDU subjects, were gathered and their qualities were assessed. HIV prevalence was pooled for each gender and stratified to several categories. The prevalence of HIV in non-IDUs and IDUs was compared using pooled odds ratios in a fixed meta-analysis model.

RESULTS

Overall, 10 studies with 2275 non-IDU samples were included. Six of the studies were conducted in prison settings, two in treatment centres, one in a community setting and one in a shelter setting. Four studies were performed in Tehran, the capital city of Iran. The pooled HIV prevalence was 5.4% [95% confidence interval (CI) 3.7-7.4] after 2005, which was significantly higher than the prevalence before 2005 [1.6% (95% CI 1.0-2.3)]. IDUs were 4.36 (95% CI 2.63-7.24) times more likely to be infected with HIV than non-IDUs.

CONCLUSION

Iran is facing a major HIV epidemic among non-injecting illicit drug users, which necessitates an urgent preventive response.

Personality differences between drug injectors and non-injectors among substance-dependent patients in substitution treatment

BACKGROUND

Understanding personality differences between injectors and non-injectors in substitution treatment may provide new insights to help improve treatment programs.

OBJECTIVE

The aim of this study was to compare drug injectors and non-injectors in terms of personality disorders and dimensions.

METHODS

Forty participants recruited from substance abuse treatment centers (23 injectors and 17 non-injectors) completed the self-report Personality Diagnostic Questionnaire 4th version and Temperament and Character Inventory. Mann-Whitney U tests were used to compare means of personality disorder traits, temperament, and character differences between injectors and non-injectors.

RESULTS

The mean (SD) age of the sample (72.5% male) was 36.5 (8.7) years. Injectors reported more borderline personality disorders and increased global personality disturbance (p < .05). Similarly, Anticipatory worry, Shyness, and Fatigability facet scores were higher among injectors (p < .01). Attachment, Purposeful, and Congruent second nature facet scores were higher among non-injectors (p < .01).

CONCLUSION

According to the route of drug administration, drug dependents differed in terms of personality disorders and dimensions.

SCIENTIFIC SIGNIFICANCE

These results may have implications for the implementation of treatment programs. New research in this area may contribute to the understanding and prevention of intravenous drug use.

Transition from first illicit drug use to first injection drug use among rural Appalachian drug users: a cross-sectional comparison and retrospective survival analysis

AIM

The study's objectives were to characterize initiation of injection drug use, examine the independent association of specific substance use with injection drug use and determine factors associated with rates of transition from first illicit drug use to first injection among a sample of rural Appalachian drug users.

DESIGN

Interview-administered questionnaires were administered to a sample of drug users recruited via respondent-driven sampling.

SETTING

Appalachian Kentucky.

PARTICIPANTS

Injection drug users (IDUs) (n = 394) and non-IDUs (n = 109).

MEASUREMENTS

Data were collected on substance use and years from age at initiation of illicit substance use to 'event' (initiation of injection or date of baseline interview for non-IDUs). Logistic regression and Cox regression were used to identify factors associated with life-time injection drug use and transition time to injection, respectively.

FINDINGS

OxyContin(®) was involved in nearly as many initiations to injection (48%), as were stimulants, other prescription opioids and heroin combined; for participants who initiated with OxyContin(®), the median time from which they began OxyContin(®) use to their first injection of OxyContin(®) was 3 years. Adjusting for demographics, five prescription drugs (benzodiazepines, illicit methadone, oxycodone, OxyContin(®) and other opiates) were associated with an increased hazard for transitioning from first illicit drug use to first injection drug use (each at P < 0.01).

CONCLUSIONS

In Appalachia, in the United States, the prescription opioid OxyContin(®) is widely used non-medically and appears to show a particularly high risk of rapid transition to injection compared with the use of other illicit drugs.

HIV prevalence and sexual risk behaviour among non-injection drug users in Tijuana, Mexico

Prior studies estimate HIV prevalence of 4% among injection drug users (IDUs), compared with 0.8% in the general population of Tijuana, Mexico. However, data on HIV prevalence and correlates among non-injecting drug users (NIDUs) are sparse. Individuals were recruited through street outreach for HIV testing and behavioural risk assessment interviews to estimate HIV prevalence and identify associated sexual risk behaviours among NIDUs in Tijuana. Descriptive statistics were used to characterise 'low-risk' NIDUs (drug users who were not commercial sex workers or men who have sex with men). Results showed that HIV prevalence was 3.7% among low-risk NIDUs. During the prior six months, 52% of NIDUs reported having >1 casual partner; 35% reported always using condoms with a casual partner; and 13% and 15%, respectively, reported giving or receiving something in exchange for sex. Women were significantly more likely than men to have unprotected sex with an IDU (p<0.01).

CONCLUSIONS

The finding that HIV prevalence among NIDUs was similar to that of IDUs suggests that HIV transmission has occurred outside of traditional core groups in Tijuana. Broad interventions including HIV testing, condom promotion and sexual risk reduction should be offered to all drug users in Tijuana.

Seroprevalence and correlates of HIV and HCV among injecting drug users in Edmonton, Alberta

BACKGROUND

Injection drug users (IDUs) are at risk for acquiring human immunodefiency virus (HIV) and hepatitis C virus (HCV) via parenteral and sexual transmission. We determined the seroprevalence and correlates of HIV and HCV for IDUs recruited in Edmonton, Alberta.

METHODS

Edmonton was one site of a multi-site, national survey (I-Track Study). From April to June 2005, IDUs were recruited and administered a questionnaire collecting information on demographics, drug use, sexual behaviours, and HIV/HCV testing behaviours. Finger-prick blood samples were collected for serology testing. Seroprevalence of HIV and HCV was determined and correlates of infection were assessed using logistic regression.

RESULTS

Of 275 IDUs, 68% were male, the median age was 38 years and 70.6% were Aboriginal. HIV prevalence was 23.9%, HCV prevalence was 66.1% and HIV/HCV co-infection was 22.8%. Cocaine (36.9%) was reported to be the drug injected most often in the previous six months. Correlates for HIV were sex trade (OR 2.9, 95% CI 1.0-8.3) for women, and older age (OR 1.1, 95% CI 1.0-1.2) and needle exchange program (NEP) use (OR 5.7, 95% CI 1.3-23.7) for men. For women, having a casual sex partner was protective for HCV (OR 0.28, 95% CI 0.10-0.78). Independent correlates for HCV among males included age (AOR 1.2, 95% CI 1.1-1.3) and younger age of first injection (AOR 0.92, 95% CI 0.87-0.96).

CONCLUSION

The high HIV and HCV prevalence found in this study among IDUs in Edmonton highlights the complex needs of the IDU community and the continued need for targeted programming.

Sex differences amongst dependent heroin users: histories, clinical characteristics and predictors of other substance dependence

INTRODUCTION AND AIMS

To examine differences in the characteristics and histories of male and female dependent heroin users, and in the clinical characteristics associated with multiple substance dependence diagnoses.

DESIGN AND METHODS

1513 heroin dependent participants underwent an interview covering substance use and dependence, psychiatric history, child maltreatment, family background, adult violence and criminal history. Family background, demographic and clinical characteristics were analysed by sex. Ordinal regression was used to test for a relationship between number of substance dependence diagnoses and other clinical variables.

RESULTS

Women were more likely to experience most forms of child maltreatment, to first use heroin with a boyfriend or partner, to experience ongoing adult violence at the hands of a partner, and to have a poorer psychiatric history than men. Males had more prevalent lifetime substance dependence diagnoses and criminal histories and were more likely to meet the criteria for ASPD. Predictors of multiple substance dependence diagnoses for both sexes were mental health variables, antisocial behaviour, childhood sexual abuse, victim of adult violence, younger age at first cannabis use and overdose. As the number of dependence diagnoses increased, clinical and behavioural problems increased. Childhood emotional neglect was related to increasing dependence diagnoses for females but not males, whereas PTSD was a significant predictor for males but not females.

DISCUSSION AND CONCLUSIONS

Mental health problems, other substance dependence, childhood and adult trauma were common in this sample, with sex differences indicating different treatment needs and possible different pathways to heroin dependence for men and women.

Heroin use, dependence, and attitudes to treatment in non-treatment-seeking heroin users: a pilot study

Much research examining heroin users utilizes treatment samples; non-treatment-seeking heroin users are not well understood. It is unclear whether this group can avoid impaired control or negative sequelae commonly observed in treatment-seeking populations. During 2000 and 2001, we recruited 69 non-treatment-seeking heroin users with no treatment history. Heroin use, management strategies, treatment attitudes, and risk behaviors were assessed; the DSM-IV checklist and severity of dependence scale were completed. Study limitations and implications for heroin use and its treatment are discussed.

Smoked cocaine in socially-depressed areas

Background

The main objectives of this study are to describe the smoked cocaine user's profile in socially-depressed areas and their needs from a harm-reduction perspective, to investigate their use of smoking crack and compare the acute effects between injecting and smoking consumption.

Methods

The study took place in SAPS, Barcelona, Spain. Two focus group sessions were undertaken with a total of 8 drug users. Secondly, the 8 participants answered a structured questionnaire and in the course of the sessions, as a snowball activity, were trained to survey 6 other crack smokers.

Results

We obtained 56 questionnaires. The majority of participants were from non-European Community countries (62.69%), 70.2% of participants referred to sharing the smoking equipment. The most frequent symptoms reported during smoked cocaine were mydriasis (83.33%)), perspiration (72.92%) and compulsive object search (70.83%) During the group sessions, participants said that smoked cocaine is much more addictive than injected cocaine and causes more anxiety. Participants also reported the difficulty of changing from injected use to smoked use, due to the larger amount of cocaine needed to reach the same effects as when having injected.

Conclusions

We can conclude that the research, focused on achieving greater knowledge of the smoked cocaine user's profile, their usage of smoking crack, consumption patterns and acute effects, should be incorporated into substance misuse interventions.

Route of administration for illicit prescription opioids: a comparison of rural and urban drug users

Background

Nonmedical prescription opioid use has emerged as a major public health concern in recent years, particularly in rural Appalachia. Little is known about the routes of administration (ROA) involved in nonmedical prescription opioid use among rural and urban drug users. The purpose of this study was to describe rural-urban differences in ROA for nonmedical prescription opioid use.

Methods

A purposive sample of 212 prescription drug users was recruited from a rural Appalachian county (n = 101) and a major metropolitan area (n = 111) in Kentucky. Consenting participants were given an interviewer-administered questionnaire examining sociodemographics, psychiatric disorders, and self-reported nonmedical use and ROA (swallowing, snorting, injecting) for the following prescription drugs: buprenorphine, fentanyl, hydrocodone, hydromorphone, methadone, morphine, OxyContin^® and other oxycodone.

Results

Among urban participants, swallowing was the most common ROA, contrasting sharply with substance-specific variation in ROA among rural participants. Among rural participants, snorting was the most frequent ROA for hydrocodone, methadone, OxyContin^®, and oxycodone, while injection was most common for hydromorphone and morphine. In age-, gender-, and race-adjusted analyses, rural participants had significantly higher odds of snorting hydrocodone, OxyContin^®, and oxycodone than urban participants. Urban participants had significantly higher odds of swallowing hydrocodone and oxycodone than did rural participants. Notably, among rural participants, 67% of hydromorphone users and 63% of morphine users had injected the drugs.

Conclusions

Alternative ROA are common among rural drug users. This finding has implications for rural substance abuse treatment and harm reduction, in which interventions should incorporate methods to prevent and reduce route-specific health complications of drug use.

Prevalence and correlates of former injection drug use among young noninjecting heroin users in Chicago

Noninjecting heroin users (NIHU) that were 16-30 years old were street recruited in Chicago between 2002 and 2005 to examine factors associated with having ever injected. Participants completed computerized self-administered interviews and provided specimens for HIV and hepatitis serotesting. Of 689 NIHU, 51.2% were non-Hispanic Black, 64.4% were male, and the median age was 25 years. Former injection was reported by 17.9%; of those, 66.7% injected <10 times. Multivariable analysis identified individual and social factors that place young NIHU at increased risk of injection. Targeted interventions are necessary to prevent transitions to injection and reduce transmission of HIV and viral hepatitis infections. The study's limitations are noted.

How many people in Canada use prescription opioids non-medically in general and street drug using populations?

OBJECTIVE

Medical prescriptions for opioids as well as their non-medical use have increased in Canada in recent years. This study aimed to estimate the number of non-medical prescription opioid (PO) users in the general and street drug using populations in Canada.

METHODS

The number of non-medical PO users among the general population and the number of non-medical PO users, heroin users, or both among the street drug using population was estimated for Canada and for the most populous Canadian provinces. Different estimation methods were used: 1) the number of non-medical PO users in the Canadian general population was estimated based on Canadian availability data, and the ratio of US availability to non-medical PO use from US survey data; 2) numbers within the street drug using population were indirectly estimated based on overdose death data, and a key informants survey. Distribution and trends by usage of opioids were determined by using the multi-site Canadian OPICAN cohort data.

RESULTS

Between 321,000 to 914,000 non-medical PO users were estimated to exist among the general population in Canada in 2003. The estimated number of non-medical PO users, heroin users, or both among the street drug using population was about 72,000, with more individuals using nonmedical PO than heroin in 2003. Based on data from the OPICAN survey, in 2005 the majority of the street drug using population in main Canadian cities was non-medical PO users, with the exception of Vancouver and Montreal. A relative increase of 24% was observed from 2002 to 2005 in the proportion of the street drug using population who used non-medical POs only.

DISCUSSION

There is an urgent need to further assess the extent and patterns of non-medical prescription opioid use, related problems and drug distribution channels in Canada.

Illegal drug-attributable morbidity in Canada 2002

Use of illegal drugs is an important behavioral risk factor for burden of morbidity in developed countries. The objective was to estimate the number of diagnoses in acute care hospitals, psychiatric hospitalizations, admissions in specialized treatment, and number of days in treatment attributable to use of illegal drugs for Canada in 2002. The number of diagnoses in acute care hospitals, psychiatric hospitalizations, and hospital days were obtained from the Canadian Institute for Health Information (CIHI). Number of admissions and number of days in specialized inpatient and outpatient treatment of illegal drug dependency were obtained from provincial ministerial officials or drug addiction program coordinators. Except for effects of maternal use of drugs of addiction on the newborn, and suicide, drug-attributable fractions (DAFs) were estimated directly from available statistics in published literature. There were 61,026 illegal drug-related diagnoses in acute care hospitals, 1,517 psychiatric hospitalizations, and 139,773 admissions to specialized treatment attributable to illegal drug use in Canada. The largest contributors were mental and behavioral disorders due to psychoactive substance use in acute care hospitals, and drug psychoses in psychiatric hospitalizations. Length of stay amounted to 352,121 days in acute care hospitals, 31,508 days in psychiatric hospitals, and 2,851,829 days in specialized treatment. Drug use constitutes a major contributor to burden of morbidity in Canada. Compared to 1992, the total number of illegal drug-attributable days in 2002 increased, especially in acute hospitals by a factor of 9.6. A mixture of prevention and harm reduction measures is proposed to reduce the burden of morbidity associated with drug use.

Comparing heroin users and prescription opioid users in a Canadian multi-site population of illicit opioid users

INTRODUCTION AND AIMS

Recent data suggest increasing prescription opioid and decreasing heroin use among street drug users, yet little is known on possible differential use characteristics and outcomes associated with these drugs. [While we recognise that, correctly, these populations would need to be labelled as opioid 'abusers' or 'non-medical users', we rely on the simpler terms 'use' and 'users' for the population under study within the wider context of them being engaged overall in illicit opioid use activities.] This study compared drug use, health, and socio-economic characteristics between heroin (H)-only, prescription opioid (PO)-only and mixed heroin and prescription (PO & H) users in a Canadian multi-site cohort of illicit opioid and other drug users (OPICAN).

DESIGN AND METHODS

Data from the most recent (2005) multi-component assessment of the H-only (n = 94), PO-only (n = 304) and PO & H (n = 86) cohort sub-samples were analysed. Based on bivariate analyses of variables of interest, a multinomial logistic regression analysis (MLRA) model was computed, comparing PO-only and PO & H groups to the H-only reference group, respectively.

RESULTS

H-only users were found in two of the seven study sites. Based on the MLRA, PO-only and PO & H users, compared to H-only users, were more likely to: be older, use benzodiazepines and cocaine, use drop-in shelters and less likely to use walk-in clinics. PO-only users were also more likely to: be white; receive legal income; use drugs by non-injection; have physical health problems; and use private physician services.

DISCUSSION AND CONCLUSIONS

Our study underscores the increasing prevalence of PO compared to heroin use in the study population. Differences between PO-only and H-only users were more pronounced than differences between PO-only and PO & H users. PO-only use may be associated with lowered health risks and social burdens, yet concerns regarding polysubstance use and drug sourcing arise. Challenges for targeted interventions are discussed.