Comparing injection and non-injection routes of administration for heroin, methamphetamine, and cocaine users in the United States

Blood pressure response to extended-release naltrexone in heroin and prescription opioid users and its implications for cardiovascular morbidity

BACKGROUND

Consuming opioid agonists is a risk factor for cardiovascular disease particularly in intravenous heroin users. The monthly injectable extended-release opioid antagonist, naltrexone (XR-NTX) is an effective treatment for opioid use disorder. The impact of opioid receptor blockade through XR-NTX on blood pressure, a critical risk factor for cardiovascular morbidity, has not yet been characterized.

METHODS

The study evaluated the change in blood pressure during XR-NTX treatment among 14 patients who predominately used intravenous heroin and 24 patients who used prescription oral opioids, all with opioid use disorder. Blood pressure was measured in each patient immediately before the first XR-NTX injection and ∼two weeks after the first injection. The change in diastolic and systolic pressure was compared between the heroin users and the prescription opioids users using analysis of variance.

RESULTS

XR-NTX treatment was associated with significant decreases in diastolic blood pressure in the heroin group, but not in the prescription opioids group. Systolic blood pressure values in the heroin users showed a decline at trend level only.

CONCLUSIONS

Further research is warranted to replicate our findings and to determine whether XR-NTX effect is relatively specific to blood pressure or generalizes to other components of metabolic syndrome. Distinguishing between heroin and prescription opioid users could shed light on the unique clinical and pharmacological profiles of opioid drugs, particularly regarding their cardiovascular safety. This information can be useful in developing personalized therapeutic strategies based on the route of opioid administration.

The influence of transformations in supply on methamphetamine initiation among people injecting opioids in the United States

BACKGROUND

Co-use of methamphetamine (MA) and opioids (pharmaceutical pills, heroin and fentanyls) has increased in the United States and is represented in rising mortality. Although coinciding with the import of low cost, high potency and purity methamphetamine, the relationship between supply and demand in propelling this polydrug use is not well understood. We consider the influence of macro changes in supply on the uptake of opioid and methamphetamine co-use by injection at the level of individual drug and injection initiation in West Virginia, a state which leads the US in drug overdose mortality.

METHOD

We recruited n = 30 people for semi-structured interviews who self-reported injecting heroin/fentanyl and using methamphetamine by any route at a West Virginia syringe service program and through snowball sampling. Interviews were recorded and transcripts analyzed using a thematic approach. Ethnographic observation was also conducted and recorded in fieldnotes. Sequence of substance and mode of use initiation and use trajectories for opioids and stimulants were charted for each participant.

RESULTS

A clear pattern of individual drug initiation emerged that matched each successive supply wave of the US overdose epidemic: 25 participants had initiated opioid use with pills, followed by heroin, often mixed with/replaced by fentanyl, and subsequently added methamphetamine use. For participants, the supply and consumption of opioid analgesics had set in motion a series of steps leading to the addition of stimulant injection to existing opioid injecting repertoires. Unlike other studies that have found a birth cohort effect in patterns of initiation, participants showed the same sequence across age groups. Considerations of economy, availability, dependence, tolerance and the erosion of taboos that marked transitions from opioid pills to heroin injection influenced these subsequent trajectories in novel ways. The form, timing and extent of opioid and stimulant consumption was influenced by four stages of the changing drug supply, which in turn reflected back on demand.

CONCLUSION

Transformations in the social meaning and supply of methamphetamine enabled these transitions while other desired, non-injectable drugs were difficult to obtain. We discuss policy implications of injectable drugs' market dominance at this location and possible interventions.

Cocaine use and head and neck cancer risk: A pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

BACKGROUND

Cocaine is an illegal recreational drug used worldwide, yet little is known about whether cocaine inhalation (smoking/snorting) increases the risk of head and neck cancer (HNC).

METHODS

The analyses were conducted by pooling data from three case-control studies with 1639 cases and 2506 controls from the International Head and Neck Cancer Epidemiology Consortium. Epidemiologic data, including cocaine use histories, were obtained in face-to-face interviews. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using hierarchical logistic regression models.

RESULTS

Controlling for cumulative tobacco and alcohol use, we observed a weak positive association between cocaine use and HNC (ORever vs. never  = 1.35, 95% CI: 0.96, 1.90). In stratified analysis, while we did not detect associations among never tobacco or alcohol users due to the limited sample size, the association with cocaine use was observed among tobacco users and alcohol drinkers. ORs for ever and high cumulative use (>18 times) versus never use were 1.40 (95% CI: 0.98, 2.00) and 1.66 (95% CI: 1.03, 2.69) among tobacco users, and 1.34 (95% CI: 0.93, 1.92) and 1.59 (95% CI: 1.00, 2.51) among alcohol drinkers, respectively.

CONCLUSION

In this pooled analysis, we observed a weak positive association between cocaine inhalation and HNC risk. Our findings provide preliminary evidence of the potential carcinogenic effect of cocaine on HNC. Because of study limitations, including limited number of cocaine users, confounding, and heterogeneity across studies, future investigations will require larger studies with more detailed information on cocaine use history.

Evidence of telescoping in females across two decades of US treatment admissions for injection drug use: 2000-2020

Background

People who inject drugs (PWID) have an increased risk of soft tissue infection, drug overdose and death. Females may be particularly vulnerable due to barriers to substance use disorder (SUD) treatment entry, stigma, and telescoping, or the greater severity in substance use-related comorbidity and consequences despite a shorter history of use. We set out to identify sex differences in United States injection drug use (IDU).

Methods

The Treatment Episode Dataset-Admission (2000-2020) provided data to identify PWID undergoing their initial SUD treatment admission. Mann-Whitney U test, chi-square, and Spearman correlations were used for ordinal variables, categorical variables, and to assess similarity of male/female trends over the 21 years, respectively. The probabilistic index (PI) and Cramer's V provided effect sizes for Mann-Whitney U tests and chi-square tests, respectively.

Results

A total of 13,612,978 records existed for cases entering their initial treatment. Mapping to a history of IDU left 1,458,695 (561,793 females). Females had a higher prevalence among PWID across all 21 years; IDU trends were essentially identical between males and females (r = 0.97). Females endorsed beginning their primary substance later in life (PI = 0.47, p < 0.0001) and entered treatment after a shorter period of substance use (PI = 0.57, p < 0.0001).

Conclusions

We saw evidence of telescoping among PWID with a SUD entering their initial episode of treatment. Interventions should be implemented prior to the transition to IDU, and this window of opportunity is shortened in females. Utilizing gender-responsive treatment options may be a way to increase treatment-seeking earlier in the disease course.

Psychiatric comorbidities and concurrent substance use among people who inject drugs: a single-centre hospital-based study

The management of people who inject drugs (PWID) is compounded by the presence of psychiatric comorbidities leading to frequent relapses and poor treatment outcomes. Early identification and treatment of psychiatric comorbidities should be included in the management to enhance treatment outcomes. The objective of this study was to estimate the prevalence of psychiatric comorbidities and concurrent substance use among opioid injectors. This hospital-based, cross-sectional study was conducted from March 2021 to August 2022. This study included opioid injectors of all ages and both sexes. The Mini International Neuropsychiatric Interview-7 (MINI-7) and WHO-ASSIST were used to determine psychiatric comorbidities and concurrent substance use, respectively. Both crude and adjusted odds ratios were calculated to assess associations among demographic variables, concurrent substance use and psychiatric comorbidities. Among the 328 opioid injectors, the overall prevalence of psychiatric comorbidities was 88.1%, with the majority (68.6%) having more than one comorbidity. The most common psychiatric comorbidities were panic disorder (41.2%), social anxiety disorder (40.5%), and antisocial personality disorder (39.3%). Concurrent use of alcoholic beverages doubled the risk of ASPD (odds ratio 2.14 (1.24-3.72)). Cocaine (odds ratio 2.36 (1.10-5.03)) and amphetamines (odds ratio 7.68 (2.21-26.65)) increased the risk of OCD. Daily heroin injections were negatively associated (odds ratio 0.18 (0.03-0.94)) with psychotic disorders. Younger age (adjusted odds ratio 0.20 (0.79-0.53)) and never married status (adjusted odds ratio 2.62 (1.06-6.47)) were the only significant variables in the regression analysis. In conclusion, opioid injectors had a higher prevalence of numerous psychiatric comorbidities. The most common comorbidity was anxiety disorders. Concurrent use of tobacco, cannabis, cocaine, inhalants, etc., greatly increased the risk of psychiatric comorbidities.

High levels of interest in access to free safer smoking equipment to reduce injection frequency among people who inject drugs in Seattle, Washington

Background

Drug use route transition interventions promote safer consumption by facilitating a switch from injection to safer routes such as smoking or oral consumption.

Methods

We performed a descriptive analysis using data from questions about "free, clean equipment for smoking" heroin, methamphetamine and/or crack from the Seattle 2018 National HIV Behavioral Surveillance survey of people who inject drugs (N = 555). We estimated the proportion of respondents with access to free safer smoking equipment, and among these participants, the proportion who reported that this access reduced their injection frequency. Among respondents without access to free safer smoking equipment, we described the proportion who were interested in getting access, and whether they thought this access would reduce their injection frequency.

Results

Among participants who reported prior year heroin (n = 495), methamphetamine (n = 372), or crack (n = 88) injection, 11%, 11% and 12% reported access to free safer smoking equipment, respectively. Of those with access, the proportion that reported that access reduced their injection frequency ranged from 12% to 44%. Among participants without access, 28% who used heroin, 45% who used methamphetamine, and 49% who used crack were interested in access. Of interested participants, a majority reported that they thought this access would reduce their frequency of injection.

Conclusions

Access to free safer smoking equipment was limited. Many participants were interested in getting free safer smoking equipment and reported that this access may reduce their injection frequency. Safer smoking equipment is a harm reduction strategy that should be available to reduce risks from opioid and stimulant injection.

Defining and measuring 'inhalant' use in population-based surveys

BACKGROUND

The term 'inhalants' is commonly used to describe a group of drugs that are characterised by the route of administration. There are three main sub-groups of inhalants; volatile solvents, alkyl nitrites, and nitrous oxide. These drugs all have different pharmacological properties, use patterns, and potential harms; yet they are sometimes grouped together in survey instruments. This critical review aimed to present a comparative analysis of how these inhalant drugs are defined, and use measured, across a range of population-level drug use surveys.

METHODS

Population-level drug use surveys of youth (n=5) and general population (n=6), which measured use of at least once type of inhalant drug, were analysed as case studies. The types of inhalants surveyed were extracted, as well as definitions of these drugs, from code books or survey methods.

RESULTS

Differing definitions were used between surveys, and included differences between countries, and between surveys intended to measure youth and general population drug use. Of the six general population surveys; five reported nitrous oxide use, five reported volatile solvent use, and four reported alkyl nitrite use. Of the five youth-specific surveys; three reported volatile solvent use, whereas only one reported on alkyl nitrite use, and one reported nitrous oxide use.

CONCLUSIONS

There is no consistent approach used to define or measure the use of inhalant drugs, which has implications for global comparisons and understanding drug use in different populations. We conclude that the term 'inhalants' should be discontinued, due to the limited value in continuing to group very different types of drugs solely on the basis of their route of administration. Improving the epidemiology of volatile solvents, alkyl nitrites, and nitrous oxide as distinct drug types will be of benefit to harm reduction, treatment, and prevention efforts, and ensure these are targeted appropriately to population groups and context of use.

Individuals Reporting Past 3-month Smoked Stimulant Use Are Placed at Risk for Infection and Injury Amid COVID-19

OBJECTIVES

Smoking stimulants, such as methamphetamine and "crack" cocaine, can spread infections, including hepatitis C and COVID-19, and lead to injuries, particularly when individuals share or use makeshift pipes. The purpose of the study was to assess the practices of people who inhale ("smoke") stimulants to guide future clinical harm reduction efforts.

METHODS

Anonymous surveys were administered to participants reporting inhalation of crack cocaine and/or methamphetamine in the past 3 months. Participants were eligible if they sought services from an outreach team staffed by a municipal syringe service program (SSP) or if they were patients at a low-threshold substance use disorder treatment program, the Massachusetts General Hospital Bridge Clinic.

RESULTS

The survey was administered to 68 total participants, 30% of whom were recruited in the Massachusetts General Hospital Bridge Clinic and 70% through SSP outreach. Unsafe smoking practices were reported by 93% of participants. Among the 46% of participants surveyed who both smoked and injected stimulants, 61% of those participants stated that they injected instead of smoked stimulants because of lack of access to pipes. Amid COVID-19, 35% of participants adopted safer smoking practices. Most participants reported that they would be more likely to attend an SSP or health center if pipes were provided.

CONCLUSIONS

Inhalational practices that place participants at risk of injury and illness are common. Providing safer smoking equipment may promote health and engage individuals in care.

Medical Complications of Injection Drug Use - Part I

Medical Complications of Injection Drug Use - Part IDuring the past 2 decades, the risk of death and the prevalence of hospitalizations in the United States have increased substantially among people who inject drugs, in large part because of the opioid epidemic. This article reviews the complications observed in people who inject drugs as well as strategies to reduce harm.

Race-based differences in drug use prior to onset of opioid use disorder

Rates of opioid use disorder (OUD) have increased dramatically over the past two decades, a rise that has been accompanied by changing demographics of those affected. Early exposure to drugs is a known risk factor for later development of opioid use disorder; but how and whether this risk factor may differ between racial groups is unknown. Our study seeks to identify race differences in self-report of current and past substance use in OUD-diagnosed treatment-seeking individuals. Patients (n = 157) presenting for methadone maintenance treatment at a racially diverse urban opioid treatment program were approached and consented for study involvement. Participants were administered substance use history questionnaires and urine drug screening at intake. Chi-square, t-tests, and rank-sum were used to assess race differences in demographic variables. Logistic and linear regressions assessed the relationship between race and substance use for binary and continuous variables, respectively. 61% of the population identified as Black and 39% as White. Black participants were significantly older; age was thus included as a covariate. Logistic regressions demonstrated that despite similar urine toxicology at intake, White participants were significantly more likely to report having used prescription opioids and psychedelic, stimulant, and sedative substance classes prior to their first use of non-pharmaceutical opioids. Compared to Black participants, White treatment-seeking OUD-diagnosed individuals reported using a wider range of substances ever and prior to first use of non-pharmaceutical opioids. There were no differences, however, in presentation for OUD treatment, suggesting different pathways to OUD, which may carry important clinical implications.

Implementing syringe services programs within the Veterans Health Administration: facility experiences and next steps

Syringe services programs are community-based prevention programs that provide evidence-based, lifesaving services for people who use illicit drugs, including access to syringes, naloxone, fentanyl test strips, infection screening, and linkage to treatment. Historically, syringe services programs did not exist within the Veterans Health Administration owing to many factors, including lack of clarity regarding legality for federal agency-purchased syringes. Three champions at Veterans Affairs facilities in Danville, IL, Orlando, FL, and San Francisco, CA, worked to clarify legal considerations, address barriers, and implement syringe services programs that are integrated in the health care systems. Since 2017, these 3 programs have engaged approximately 400 Veterans and distributed nearly 10,000 syringes, 2500 fentanyl test strips, 50 wound care kits, and 45 safer sex kits. These programs, both led by and in collaboration with clinical pharmacist practitioners, paved the way for nationwide implementation within the Veterans Health Administration. This commentary describes successes, challenges, and proposed next steps to increase Veteran access to syringe services programs, written from the perspective of 3 facility-based champions.

Trends and distinct profiles of persons who inject drugs in the United States, 2015-2019

Drug injection represents a major health problem in the US, with severe health consequences including the transmission of blood-borne infections. An examination of the most recent trends in drug injection is warranted by the fast-evolving drug epidemic and recent policy changes such as the federal funding ban on needle exchange programs. This research examines current drug injection trends, patterns, and socioeconomic and behavioral profiles of people who inject drugs (PWID). Data were derived from the 2002 to 2019 National Survey on Drug Use and Health (NSDUH). After examining the annual prevalence of drug injection since 2002, a latent class analysis was conducted to identify drug injection and other substance misuse patterns among PWID using the latest (2015-2019) NSDUH datasets. Associations between class membership and behavioral health comorbidities and treatment receipt were also assessed. The drug injection prevalence among US adults aged 18-64 increased from 0.21% in 2002/2004 to 0.36% in 2017/2019. Three distinctive groups were identified: the heroin injection group (45.2%), the methamphetamine injection group (28.0%), and the multi-drug injection group (26.8%). The methamphetamine injection group reported greater risks of experiencing serious psychological distress, suicidality, and limited substance use treatment. Special attention is needed for those who primarily injected methamphetamine. Programs to promote harm reduction and increase access to addiction treatment need to be expanded in at-risk communities while accounting for their distinct socioeconomic and drug use/misuse profiles.

Heroin pipe distribution to reduce high-risk drug consumption behaviors among people who use heroin: a pilot quasi-experimental study

BACKGROUND

Heroin pipe distribution may encourage people who use heroin (PWUH) to transition from injecting to smoking heroin, reducing harms associated with injection drug use. A syringe services program (SSP) in Seattle, Washington, led by people who use drugs developed a heroin pipe distribution program.

METHODS

We conducted a pretest-posttest quasi-experimental study to evaluate the impact of heroin pipe distribution on drug consumption behaviors among PWUH between March and December 2019. SSP clients were surveyed during three weeklong timepoints before and four weeklong timepoints after heroin pipe distribution. Primary outcomes were change in proportion of SSP clients who exclusively injected heroin, exclusively smoked heroin, and both injected and smoked heroin in the past seven days comparing the pre- and post-intervention periods.

RESULTS

Across the seven observation timepoints, 694 unique respondents completed 957 surveys. Multiple responses from a single respondent in a given period were collapsed, resulting in 360 pre-intervention and 430 post-intervention records. Heroin use was reported in over half of pre-intervention (56%, 201/360) and post-intervention records (58%, 251/430). Compared to pre-intervention behaviors, the proportion of respondents who exclusively injected heroin was lower after the start of heroin pipe distribution (32%, 80/251 vs 43%, 86/201, p = 0.02), while the proportion of respondents who both injected and smoked heroin was higher (45%, 113/251 vs 36%, 72/201, p = 0.048). Just under half (44%, 110/251) of respondents who used heroin during the post-intervention period used a heroin pipe obtained from the SSP, of which 34% (37/110) reported heroin pipe distribution had reduced their heroin injection frequency. Self-reported hospitalization for a pulmonary cause was not associated with using a heroin pipe.

CONCLUSIONS

The proportion of SSP clients who exclusively injected heroin was lower after implementation of heroin pipe distribution. Randomized studies with longer follow-up are needed to investigate whether heroin pipe distribution reduces heroin injection and improves health outcomes associated with drug use. Limited intervention exposure, loss to follow-up, and pipe availability from other sources pose methodological challenges to evaluations of route transition interventions in community settings. This pilot highlights the potential for organizations led by people who use drugs to develop, implement, and evaluate novel public health programming.

Understanding injecting drug use in Afghanistan: A scoping review

Background

Several reports have described a growing prevalence of illicit drug use in Afghanistan, with recognition of a recent shift from traditional modes of consumption involving inhalation and oral ingestion to injecting drug use.

Objective

Conduct a comprehensive review of existing literature to map the injecting drug use situation in Afghanistan. The review intends to describe risk factors and impacts of injecting drug use, drug use characteristics and risk behaviours among people who inject drugs (PWID), and access to harm reduction and treatment.

Methods

We searched Embase, Global Health, Medline, PsycINFO, Web of Science, and grey literature to identify English language publications up to March 26^th, 2022. Studies were eligible for inclusion if they explicitly targeted PWID or injecting drug use in Afghanistan and provided information relevant to the review questions. Two reviewers independently screened titles and abstracts for inclusion and extracted information based on the review objectives.

Results

A total of 25 articles were identified representing 15 studies (11 quantitative, 2 qualitative, 2 mixed methods). All but one studies were cross-sectional. In majority of the studies, over 95% of the participants were male and most were conducted over a decade ago, in urban settings, mainly Kabul. Only one study examined risk factors of injecting drug use. Eleven studies described drug use characteristics and 9 reported risk behaviours among PWID. Health and social burden of injecting drug use were reported by 8 and 5 studies, respectively. Nine studies described access to harm reduction and treatment. Afghan PWID had high levels of injecting and sexual risk behaviours compared to global estimates. They reported high prevalence of incarceration and displacement. Access to harm reduction and treatment was very limited. This scoping review revealed important knowledge gaps including a gender gap in research with serious implications for drug policy and substance use care.

Conclusions

Development of a national public health-oriented drug policy and substance use care programme is warranted along with efforts to develop health research capacity to address the need for epidemiological data. The current humanitarian crisis necessitates continued access to evidence-based harm reduction and treatment in Afghanistan.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13011-022-00491-1.

Disrupted Decision-Making: EcoHIV Inoculation in Cocaine Dependent Rats

Independently, chronic cocaine use and HIV-1 viral protein exposure induce neuroadaptations in the frontal-striatal circuit as evidenced by both clinical and preclinical studies; how the frontal-striatal circuit responds to HIV-1 infection following chronic drug use, however, has remained elusive. After establishing experience with both sucrose and cocaine self-administration, a pretest-posttest experimental design was utilized to evaluate preference judgment, a simple form of decision-making dependent upon the integrity of frontal-striatal circuit function. During the pretest assessment, male rats exhibited a clear preference for cocaine, whereas female animals preferred sucrose. Two posttest evaluations (3 days and 6 weeks post inoculation) revealed that, independent of biological sex, inoculation with chimeric HIV (EcoHIV), but not saline, disrupted decision-making. Prominent structural alterations in the frontal-striatal circuit were evidenced by synaptodendritic alterations in pyramidal neurons in the medial prefrontal cortex. Thus, the EcoHIV rat affords a valid animal model to critically investigate how the frontal-striatal circuit responds to HIV-1 infection following chronic drug use.

Demographic and geographic shifts in the preferred route of methamphetamine administration among treatment cases in the US, 2010-2019

BACKGROUND

Methamphetamine use disorder has increased rapidly in the past decade. Injecting is also increasing and has multifaceted implications for disease severity, overall health, and treatment outcomes, but less is known about where or among whom injecting has shifted the most. This national study assessed temporal changes in the preferred route of methamphetamine administration by race/ethnicity and within urban/rural geographies.

METHODS

We used the Treatment Episode Dataset-Discharges (2010-2019) to identify outpatient treatment cases who reported methamphetamine as their primary drug of choice at admission (N = 531,799; 2010 n = 33,744; 2019 n = 81,885). We created a combined variable indicating race/ethnicity and the rural/urban location of treatment, and used logistic regression to model the predicted probability of cases reporting injection, smoking, or snorting as their preferred route of administration. We included an interaction term to determine differences over time (race/ethnicity/rurality*year).

RESULTS

Across all years, smoking methamphetamine was the most common route of administration (66%), followed by injection (24%) and snorting (10%). Over time and among most sub-groups, the rates of injection increased while the rates of smoking decreased. Compared to 2010, the odds of injecting methamphetamine in 2019 were highest among Black cases in urban areas (aOR = 2.30, 95% CI = 1.76-3.00, p < 0.0001).

CONCLUSION

Increasing methamphetamine injection was most pronounced among Black treatment cases in more urban areas, which is in contrast to the longstanding narrative that methamphetamine is a White and rural drug. Methamphetamine prevention, treatment, and harm reduction should target populations with high injection prevalence and growing incidence.

Estimated number of injection-involved drug overdose deaths, United States, 2000 - 2018

BACKGROUND

In the United States, drug overdose mortality has increased. Death records categorize overdose deaths by type of drug involved, but do not include information about the route of drug administration.

METHODS

We utilized data from drug treatment admissions (Treatment Episodes Dataset, TEDS-A) and National Vital Statistics Systems to estimate the percentage of reported drug overdose deaths that were injection-involved from 2000 to 2018 in the U.S. Data on reported route of administration at admission were used to calculate the percent injecting each drug type, by demographic group (race/ethnicity, sex, age group) and year. Using the resulting probabilities, we estimated the number of overdose deaths that were injection-involved. Estimates were compared across drug types, demographic characteristics, and year.

FINDINGS

The number of overdose deaths among adults increased more than 3-fold from 2000 (n = 17,196) to 2018 (n = 67,021). During that timeframe, the number of estimated injection-involved overdose deaths increased more than 8-fold from 2000 (n = 3467, 95% CI: 3449-3485) to 2018 (n = 28,257, 95% CI: 28,192-28,322). From 2000-2007, the percent of overdose deaths that were injection-involved remained stable around 20%. From 2007-2018, the percent of overdose deaths that were injection-involved increased from 18.4% (95% CI: 18.3-18.6%) to 42.2% (95% CI: 42.1-42.3%). In 2018, most estimated injection-involved overdose deaths were due to injecting heroin/synthetic opioids (n = 24,860, 95% CI: 24,800-24,919), which accounted for 88.0% of all injection-involved deaths.

CONCLUSIONS

Much of the recent increase in overdose mortality is likely attributable to rising injection-involved overdose deaths.

Comparisons of injection and non-injection opioid use among Black people in methadone treatment: A pilot in Detroit

Rates of injection drug use (IDU) of opioids have been consistently lower among Black people relative to Non-Hispanic White people despite rising IDU estimates. While explanations have been proposed, no study has explored differences within a clinical sample of Black people in treatment who prefer IDU to non-IDU opioid administration. The purpose of this pilot study was to explore these differences guided by a seminal framework (e.g., market force, social network, and risk-taking characteristics), along with mental health symptoms, needle phobia, and injection perception variables. A purposive sample of 50 Black participants (58.0% male) were recruited from an opioid treatment program in Detroit by their preference for IDU (n = 16) versus non-IDU. The IDU group was younger, less educated, and younger at first treatment episode. They were more likely to report having been told they had bipolar disorder, PTSD, or anxiety, receiving mental health services as adults, and have a spouse/partner and close friends who injected opioids. The non-IDU group endorsed more symptoms of needle phobia. The non-IDU group also agreed more with statements that family and friends believe police mistreat people who inject drugs, and that people who inject opioids have a harder time quitting, are more likely to die from overdose, and have a harder time hiding it from family. These initial findings provide a rationale for a larger study with sex-specific analysis on factors associated with IDU among Black people to inform harm reduction efforts.

Under the Skin: The Relationship Between Subcutaneous Injection and Skin Infections Among People Who Inject Drugs

OBJECTIVES

People who inject drugs (PWID) are at increased risk for numerous negative health outcomes. Subcutaneous injections (aka skin popping) can result in greater risk of skin and soft tissue infections (SSTIs), but less is known about PWID who choose this route of administration. This study compares subcutaneous injectors to intravenous injectors, characterizes those who inject subcutaneously, and examines whether subcutaneous injection is associated with SSTIs in the past year.

METHODS

A cohort of hospitalized PWID (n = 252) were interviewed regarding injection-related behaviors, history of SSTI, and knowledge of subcutaneous injection risk. We examined differences between those who do and do not inject subcutaneously and used a negative binomial regression model to estimate adjusted odds associating subcutaneous injection and SSTI.

RESULTS

Participants averaged 38 years, with 58.3% male, 59.5% White, 20.6% Black, and 15.9% Latinx. PWID who performed subcutaneous injection were not demographically different from other PWID; however, the mean rate of past year SSTIs was higher for persons injecting subcutaneously than for those who did not (1.98 vs 0.96, P < 0.001). Persons injecting subcutaneously did not differ from those who injected intravenously in terms of their knowledge of subcutaneous injection risk (P = 0.112) and knowledge score was not associated with SSTIs (P = 0.457).

CONCLUSIONS

PWID who perform subcutaneous injections are demographically similar to other PWID but had higher rates of past year SSTIs. Knowledge of subcutaneous injection risk was not associated with SSTI risk.

Harm Reduction in Health Care Settings

Harm reduction is an approach to reduce the risk of harms to an individual using substances without requiring abstinence. This review discusses substance-specific interventions for opioids, alcohol, and stimulants that can minimize harms for individuals who use these substances. Topics discussed include overdose prevention, infection prevention, and low-barrier substance use disorder treatment.

Routes of Administration of Illicit Drugs among Young Swiss Men: Their Prevalence and Associated Socio-Demographic Characteristics and Adverse Outcomes

The prevalence of different routes of administration (ROAs) of illicit drugs other than cannabis was examined in young Swiss men, in addition to the association between socio-demographics and adverse outcomes and particular ROAs. Our sample consisted of 754 men (mean age = 25.4 ± 1.2 years) who participated in the Cohort Study on Substance Use Risk Factors and reported using any of 18 illicit drugs over the last 12 months. Prevalence estimates were calculated for oral use, nasal use, smoking, injecting, and other ROAs. Associations between ROAs and socio-demographics and adverse outcomes (i.e., alcohol use disorder (AUD), suicidal ideations, and health and social consequences) were calculated for using single versus multiple ROAs. The most prevalent ROA was oral use (71.8%), followed by nasal use (59.2%), smoking (22.1%), injecting (1.1%), and other ROAs (1.7%). Subjects’ education, financial autonomy, and civil status were associated with specific ROAs. Smoking was associated with suicidal ideations and adverse health consequences and multiple ROAs with AUD, suicidal ideations, and health and social consequences. The most problematic pattern of drug use among young adults appears to be using multiple ROAs, followed by smoking. Strategies to prevent and reduce the use of such practices are needed to avoid adverse outcomes at this young age.

Analysis of genetic and clinical factors associated with buprenorphine response

BACKGROUND

Buprenorphine, approved for treating opioid use disorder (OUD), is not equally efficacious for all patients. Candidate gene studies have shown limited success in identifying genetic moderators of buprenorphine treatment response.

METHODS

We studied 1616 European-ancestry individuals enrolled in the Million Veteran Program, of whom 1609 had an ICD-9/10 code consistent with OUD, a 180-day buprenorphine treatment exposure, and genome-wide genotype data. We conducted a genome-wide association study (GWAS) of buprenorphine treatment response [defined as having no opioid-positive urine drug screens (UDS) following the first prescription]. We also examined correlates of buprenorphine treatment response in multivariable analyses.

RESULTS

Although no variants reached genome-wide significance, 6 loci were nominally significant (p < 1 × 10^-5), four of which were located near previously characterized genes: rs756770 (ADAMTSL2), rs11782370 (SLC25A37), rs7205113 (CRISPLD2), and rs13169373 (LINC01947). A higher maximum daily buprenorphine dosage (aOR = 0.98; 95 %CI: 0.97, 0.995), greater number of UDS (aOR = 0.97; 95 %CI: 0.96, 0.99), and history of hepatitis C (HCV) infection (aOR = 0.71; 95 %CI: 0.57, 0.88) were associated with a reduced odds of buprenorphine response. Older age (aOR: 1.01; 95 %CI: 1.000, 1.02) was associated with increased odds of buprenorphine response.

CONCLUSIONS

This study had limited statistical power to detect genetic variants associated with a complex human phenotype like buprenorphine treatment response. Meta-analysis of multiple data sets is needed to ensure adequate statistical power for a GWAS of buprenorphine treatment response. The most robust phenotypic predictor of buprenorphine treatment response was intravenous drug use, a proxy for which was HCV infection.

Investigating a bidirectional relationship between overdose and provision of injection initiation assistance among persons who inject drugs in Vancouver, Canada and Tijuana, Mexico

BACKGROUND

Individuals who initiate injection drug use often receive assistance from an injection-knowledgeable peer. Persons who assist peers in injection initiation events often inject frequently, which heightens overdose risk. As such, overdose and injection initiation events may be correlated. To explore a potential relationship, we assessed temporal associations between experiencing a non-fatal overdose and assisting others in initiating injection drug use among persons who inject drugs in two North American cities - Vancouver, Canada and Tijuana, Mexico.

METHODS

From 2014 to 2018, this retrospective cohort study included people who inject drugs from Vancouver (n=1332) and Tijuana (n=666) who completed a baseline and six-month follow-up interview. Within each site, we assessed bidirectional temporal associations using two separate multivariable logistic regression models: for model 1, recent provision of injection initiation assistance (at six months) was the outcome and recent overdose (at baseline) was the exposure; for model 2, recent overdose (at six months) was the outcome and recent provision of injection initiation assistance (at baseline) was the exposure. Both models adjusted for potential confounders.

RESULTS

Vancouver-based participants reporting overdose at baseline had 163% greater odds of reporting provision of injection initiation assistance at follow-up (adjusted Odds Ratio [aOR] 2.63; 95% Confidence Interval [CI] 1.41-4.90); while participants reporting provision of injection initiation assistance at baseline had 89% greater odds of reporting a non-fatal overdose at follow-up (aOR 1.89; 95% CI 1.00-3.57). Among Tijuana-based participants, we did not observe a statistically significant association in either direction.

CONCLUSION

Findings in Vancouver suggest that injection initiation assistance and overdose are bidirectionally-associated phenomena. The present findings highlight the need for interventions that ensure that persons who provide injection initiation assistance are given overdose prevention support, both for themselves and for those they assist to initiate injection drug use. While our Tijuana-based results did not suggest a bidirectional relationship, preventative approaches should nonetheless be undertaken.

Methamphetamine in Orthopaedics: Considerations of an At-Risk Population

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Methamphetamine use by orthopaedic trauma patients has risen to epidemic proportions.

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Perioperative methamphetamine use by orthopaedic trauma patients requires physicians to consider both medical and psychosocial factors during treatment.

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Behavioral and psychosocial effects of methamphetamine use present barriers to care.

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Patients who use methamphetamine face elevated rates of complications.

Age- and Race-Related Differences in Advertised Health Behaviors Among Male Sex Workers in San Francisco Who Have Sex With Men

ABSTRACT

Given the stigma surrounding sex work and the illegal nature of many aspects of commercial sex activity, empirical research is lacking regarding the health-related behaviors of sex workers, particularly male sex workers who have sex with men (MSM sex workers). To better understand the MSM sex worker community and their potential health needs, we analyzed certain sexual health-related behaviors as advertised online by MSM sex workers in the San Francisco area. Using descriptive and bivariate statistical tests, we examined whether age- and race-related differences existed among these sex workers in the following publicly advertised behaviors: use of pre-exposure prophylaxis and a willingness to engage in illicit drug use or condomless anal intercourse. Although we found no significant differences by race in terms of advertised pre-exposure prophylaxis use or willingness to engage in condomless sex, our results show statistically significant differences by race with respect to willingness to use drugs. This difference could be driven by the younger average age of the non-White sex workers in our sample. These findings help inform our understanding of MSM sex work and its associated risks.

Rural-Urban Residence and Maternal Hepatitis C Infection, U.S.: 2010-2018

INTRODUCTION

The prevalence of hepatitis C virus infection among women delivering live births in the U.S. may be higher in rural areas where county-level estimates may be unreliable. The aim of this study is to model county-level maternal hepatitis C virus infection among deliveries in the U.S.

METHODS

In 2020, U.S. natality files (2010-2018) with county-level maternal residence information were used from states that had adopted the 2003 revised U.S. birth certificate, which included a field for hepatitis C virus infection present during pregnancy. Hierarchical Bayesian spatial models with spatiotemporal random effects were applied to produce stable annual county-level estimates of maternal hepatitis C virus infection for years when all states had adopted the revised birth certificate (2016-2018). Models included a 6-Level Urban-Rural County Classification Scheme along with the birth year and county-specific covariates to improve posterior predictions.

RESULTS

Among approximately 32 million live births, the overall prevalence of maternal hepatitis C virus infection was 3.5 per 1,000 births (increased from 2.0 in 2010 to 5.0 in 2018). During 2016-2018, posterior predicted median county-level maternal hepatitis C virus infection rates showed that nonurban counties had 3.5-3.8 times higher rates of hepatitis C virus than large central metropolitan counties. The counties in the top 10th percentile for maternal hepatitis C virus rates in 2018 were generally located in Appalachia, in Northern New England, along the northern border in the Upper Midwest, and in New Mexico.

CONCLUSIONS

Further implementation of community-level interventions that are effective in reducing maternal hepatitis C virus infection and its subsequent morbidity may help to reduce geographic and rural disparities.

Hoots and harm reduction: a qualitative study identifying gaps in overdose prevention among women who smoke drugs

BACKGROUND

Smoking or inhaling illicit drugs can lead to a variety of negative health outcomes, including overdose. However, most overdose prevention interventions, such as supervised consumption services (SCS), prohibit inhalation. In addition, women are underrepresented at SCS and are disproportionately impacted by socio-structural violence. This study examines women's experiences smoking illicit drugs during an overdose epidemic, including their utilization of a women-only supervised inhalation site.

METHODS

Qualitative research methods included on-site ethnographic observation and semi-structured interviews with 32 participants purposively recruited from the women-only site. Data were coded and analyzed using NVivo 12 and thematic analysis was informed by gendered and socio-structural understandings of violence.

RESULTS

Participants had preferences for smoking drugs and these were shaped by their limited income, inability to inject, and perceptions of overdose risk. Participants expressed the need for services that attend to women's specific experiences of gendered, race-based, and structural violence faced within and outside mixed-gender social service settings. Results indicate a need for sanctioned spaces that recognize polysubstance use and drug smoking, accommodated by the women-only SCS. The smoking environment further fostered a sociability where participants could engage in perceived harm reduction through sharing drugs with other women/those in need and were able to respond in the event of an overdose.

CONCLUSIONS

Findings demonstrate the ways in which gendered social and structural environments shape women's daily experiences using drugs and the need for culturally appropriate interventions that recognize diverse modes of consumption while attending to overdose and violence. Women-only smoking spaces can provide temporary reprieve from some socio-structural harms and build collective capacity to practice harm reduction strategies, including overdose prevention. Women-specific SCS with attention to polysubstance use are needed as well as continued efforts to address the socio-structural harms experienced by women who smoke illicit drugs.

Correlates of recent nonfatal overdose among people who inject drugs in West Virginia

Aim

Experiencing a nonfatal overdose (NFOD) is a significant risk factor for a subsequent nonfatal or fatal overdose. Overdose mortality rates in rural Appalachian states are some of the highest in the USA, but little is known about correlates of overdose among rural populations of people who inject drugs (PWID). Our study aimed to identify correlates of experiencing a recent (past 6 months) NFOD among rural PWID in Cabell County, West Virginia.

Methods

Using data from a June–July 2018 cross-sectional survey that was designed to estimate the size and characteristics of the PWID population in Cabell County, West Virginia, we used log binomial regression to identify correlates (e.g., structural vulnerabilities and substance use) of NFOD in the past 6 months.

Results

The majority of our sample of 420 PWID were male (61.2%), White, non-Hispanic (83.6%), and reported recent heroin injection (81.0%). More than two-fifths (42.6%) experienced a recent NFOD. Independent correlates of NFOD included witnessing an overdose in the past 6 months (adjusted prevalence ratio [aPR] = 2.28; 95% CI 1.48–3.50), attempting to quit using drugs in the past 6 months (aPR = 1.54; 95% CI 1.11–2.14), and the number of drugs injected (aPR = 1.16; 95% CI 1.10–1.23)

Conclusions

A large proportion of rural PWID in Appalachia reported having recently overdosed. The associations between witnessing an overdose, attempting to quit using drugs, and number of drugs injected with recent nonfatal overdose underscore the need for expanded access to overdose prevention resources that are tailored to the needs of this population. Expanding access to evidence-based overdose prevention strategies—such as take-home naloxone programs, treatment with methadone or buprenorphine, and harm reduction services—may decrease overdose morbidity and mortality among rural PWID in Appalachia.

Tracing a path for opium gum from Mexico as a safe supply harm reduction measure for Canada

Historically, the poppy plant has had multiple uses including as a food product and with medical uses in pain relief; today it is most commonly known as the plant from which heroin is derived. The United Nations international drug control regime currently only allows legal poppy production for medical use in 19 countries. Although Mexico is the third largest illegal poppy producer in the world, no Latin American country is currently allowed to legally produce poppies. Meanwhile, the United States and Canada are experiencing an overdose crisis due in large part to the adulteration and substitution of heroin with fentanyl and its analogues, while the price of opium gum has dropped 80% in the last two years in poppy producing areas of Mexico. The prohibition of opium has wide ranging health and development impacts that bring up a moral imperative regarding the safe supply of diverse opium-based products -including opium gum and heroin- that urgently need to be explored and addressed. Opium gum can be used orally or smoked, reducing riskier modes of administration and possible fatal overdoses. This article discusses the political and legal possibilities of safely supplying opium gum and manually extracted heroin from Mexico to Canada as a public health, harm reduction and development policy.

Prevalence and correlates of receptive syringe-sharing among people who inject drugs in rural Appalachia

BACKGROUND AND AIMS

Syringe-sharing significantly increases the risk of HIV and viral hepatitis acquisition among people who inject drugs (PWID). Clearer understanding of the correlates of receptive syringe-sharing (RSS) is a critical step in preventing bloodborne infectious disease transmission among PWID in rural communities throughout the United States. This study aimed to measure the prevalence and correlates of RSS among PWID in a rural county in Appalachia.

DESIGN

Observational, cross-sectional sample from a capture-recapture parent study.

SETTING

Cabell County, West Virginia (WV), USA, June-July 2018.

PARTICIPANTS

The sample was restricted to people who reported injecting drugs in the past 6 months (n = 420). A total of 180 participants (43%) reported recent (past 6 months) RSS. Participants reported high levels of homelessness (56.0%), food insecurity (64.8%) and unemployment (66.0%).

MEASUREMENTS

The main outcome was recent re-use of syringes that participants knew someone else had used before them. Key explanatory variables of interest, selected from the risk environment framework, included: unemployment, arrest and receipt of sterile syringes from a syringe services program (SSP). Logistic regression was used to determine correlates of recent RSS.

FINDINGS

PWID reporting recent RSS also reported higher prevalence of homelessness, food insecurity and unemployment than their non-RSS-engaging counterparts. In adjusted analyses, correlates of RSS included: engagement in transactional sex work [adjusted odds ratio (aOR) = 2.27, 95% confidence interval (CI) = 1.26-4.09], unemployment (aOR = 1.67, 95% CI = 1.03-1.72), number of drug types injected (aOR = 1.33, 95% CI = 1.15-1.53) and injection in a public location (aOR = 2.59, 95% CI = 1.64-4.08). Having accessed sterile syringes at an SSP was protective against RSS (aOR = 0.57, 95% CI = 0.35-0.92).

CONCLUSION

The prevalence of receptive syringe-sharing among people who inject drugs in a rural US county appears to be high and comparable to urban-based populations. Receptive syringe-sharing among people who inject drugs in a rural setting appears to be associated with several structural and substance use factors, including unemployment and engaging in public injection drug use. Having recently acquired sterile syringes at a syringe services program appears to be protective against receptive syringe sharing.

Recent developments in electrochemical detection of illicit drugs in diverse matrices

Drug abuse is a global problem, requiring an interdisciplinary approach. Discovery, production, trafficking, and consumption of illicit drugs have been constantly growing, leading to heavy consequences for environment, human health, and society in general. Therefore, an urgent need for rapid, sensitive, portable and easy-to-operate detection methods for numerous drugs of interest in diverse matrices, from police samples, biological fluids and hair to sewage water has risen. Electrochemical sensors are promising alternatives to chromatography and spectrometry. Last decades, electrochemical sensing of illegal drugs has experienced a very significant growth, driven by improved transducers and signal amplifiers helping to improve the sensitivity and selectivity. The present review summarizes recent advances (last 10 years) in electrochemical detection of the most prevailing illicit drugs (such as cocaine, heroin, and (meth)amphetamine), their precursors and derivatives in different matrices. Various electrochemical sensors making use of different transducers with their (dis)advantages were discussed, and their sensitivity and applicability were critically compared. In those cases where natural or synthetic recognition elements were included in the sensing system to increase specificity, selected recognition elements, their immobilization, working conditions, and analytical performance were discussed. Finally, an outlook is presented with suggestions and recommendations for future developments.

Impact of Recent Methamphetamine Use on Vancomycin Clearance

PURPOSE

To determine whether recent methamphetamine use increases vancomycin clearance.

METHODS

This was a multi-center, retrospective, IRB-approved study at two tertiary care medical centers. Adult patients with a urine drug screen, ≥3 consecutive vancomycin doses, and an appropriately drawn vancomycin trough were assessed and classified as amphetamine positive or amphetamine negative. The primary outcome was vancomycin clearance.

RESULTS

88 patients were included in the analysis, with 44 patients in each group. Vancomycin clearance was greater in the amphetamine positive group (94.54 vs. 86.84 mL/min, p = 0.042, 95% CI 0.29-15.09). There was no significant difference in goal vancomycin trough achievement between groups (34.1% amphetamine positive vs. 43.2% amphetamine negative; p = 0.512). Per multifactorial logistic regression analysis, older age and male gender were associated with decreased vancomycin clearance, while higher BMI and cocaine positive urine drug screen were associated with increased vancomycin clearance.

CONCLUSION

Recent methamphetamine use may increase vancomycin clearance. Larger prospective trials with protocolized vancomycin dosing strategies are needed to further elucidate the impact of methamphetamine use on attainment of goal vancomycin troughs in addition to the potential impact on vancomycin clearance.

Risk of hepatitis C virus infection in injecting and noninjecting drug users receiving opioid substitution therapy

BACKGROUND

Hepatitis C virus (HCV) is the most common viral infection among illicit drug users in the world. Although intervention of needle and syringe program and opioid substitution therapy had engaged to prevent HCV infection, the prevalence of HCV infection does not seem to decline. The aim of this study was to estimate the risk of HCV infection in injecting drug users (IDUs) and noninjecting drug users (NIDUs) receiving opioid substitution therapy.

METHODS

We recruited 1179 heroin-dependent patients (age: 20-66 years) under opioid substitution therapy from 2012 to 2015 in a Psychiatric Center, Southern Taiwan. The data of HCV, hepatitis B virus and HIV infection and liver biochemical examination were obtained. We used multivariate logistic regression analysis to predict the risk of HCV infection.

RESULTS

There were 93.1% of IDUs and 68.1% of NIDUs positive for HCV infection. In IDUs, HIV infection, age of heroin initiation, duration and dose of heroin use, frequency of detoxification, and number of criminal conviction were significantly associated with HCV infection. In NIDUs, snort/sniff heroin exhibited a significantly increased risk of HCV infection. Intravenous injecting (odds ratio [OR] = 23.10, 95% CI = 8.04-66.40, p < 0.001), intravenous injecting combined snort/sniff (OR = 12.95, 95% CI = 3.90-42.97, p < 0.001), and snort/sniff (OR = 4.14, 95% CI = 1.30-13.18, p = 0.016) were significantly associated with increased risk of HCV infection compared with smoking. The trend was significant (p for trend <0.001).

CONCLUSION

In Taiwan, IDUs had harmful characteristics compared with NIDUs and both had extremely high prevalence of HCV infection. We provided evidence that snort/sniff is a possible way of leak in HCV infection despite needle-syringes supplement program been provided. Opioid substitution therapy program should include HCV assessment and treatment in the new direct-acting antiviral therapy era.

Estimation of the impact of changing drug-use trend on HIV, hepatitis C and syphilis epidemics among people who use synthetic drug-only, polydrug and heroin-only during 2005-2035 in China: modelling study

OBJECTIVE

The rapid expansion of the recreational drug market becomes a global health concern. It is worrying that the bacterial and viral infection epidemics linking to drug use may worsen accordingly. This study aimed to estimate the impacts of changing trend and behaviours of using heroin only, synthetic drug (SD) only and polydrug (using SD and heroin concurrently) on HIV, hepatitis C virus (HCV) and syphilis epidemics among people who use drugs in China by 2035.

METHODS

We constructed a compartmental model to estimate HIV, HCV and syphilis epidemics in the dynamic drug-use trend by three scenarios: SD-only use, heroin-only use and polydrug use based on Monte Carlo simulations. The parameters for the model were collected from a comprehensive literature search.

RESULTS

Our model estimated that polydrug use led to the highest HIV and HCV prevalence among three drug-use patterns. The prevalences were projected to increase from 10.9% (95% CI 10.2% to 11.5%) and 61.7% (95% CI 59.4% to 62.5%) in 2005 to 19.0% (95% CI 17.3% to 20.7%) and 69.1% (95% CI 67.3% to 69.5%), respectively, in 2035 among people using polydrug. Similarly, HIV and HCV prevalence in the SD-only group were projected to increase from 0.4% (95% CI 0.3% to 0.4%) and 19.5% (95% CI 19.4% to 21.7%) to 1.8% (95% CI 1.4 to 2.1%) and 33.7% (95% CI 33.2% to 34.9%) in 2005-2035. Conversely, HIV prevalence in the heroin-only group was projected to decrease from 8.0% (95% CI 7.6% to 8.1%) to 2.2% (95% CI 2.0% to 2.3%) in 2005-2035. Syphilis prevalence was estimated to remain unchanged in all population groups within this time frame. It was projected that the proportion of HIV transmitted by sexual transmission will increase compared with unsafe injection transmission in all people who use drugs from 2005 to 2035.

CONCLUSION

Our modelling suggests that polydrug use is projected to lead to the highest HIV and HCV disease burden by 2035, and the proportion of HIV transmitted by sexual transmission will increase. Current HIV intervention among people using heroin seems effective according to our estimation.

Methods for Population Research on Substance Use and Consequences

This chapter reviews the array of methods used in contemporary research on population-level research on substance use and its consequences. We argue that there are critical questions that can best - or in some cases, only - be addressed at the level of a population. We then describe the major categories of data collection methods used in population research, including surveys, ecological momentary assessment, administrative data, audit methods, and unobtrusive assessment of substance use. Two categories of measures are then discussed: measures of an individual's use of substances and related problems and measures of harm to others caused by one's use. We then review factors that may be considered causes or correlates of substance use and consequences, including both individual and environmental factors. We close with a few thoughts on the accumulation of knowledge and its translation to policy and practice.

Longitudinal analysis of HIV-risk behaviors of participants in a randomized trial of prison-initiated buprenorphine

Background

It has been estimated that approximately 15% of people who are incarcerated in the US have histories of opioid use disorder. Relapse to opioid use after release from prison poses a serious risk of HIV infection. Prison-initiated buprenorphine may help to reduce HIV infection given the association between opioid use and HIV-risk behaviors.

Methods

The present study is a secondary analysis of longitudinal data gathered from a randomized controlled trial of buprenorphine-naloxone for people who were incarcerated (N = 211) between 2008 and 2012. It compares the impact of assignment to initiate buprenorphine in prison (N = 106 randomized, N = 104 analyzed) versus in the community (N = 107 randomized, N = 107 analyzed) and whether or not participants entered community treatment on the frequency of HIV-risk behaviors in the 12 months following release from prison. Data were analyzed hierarchically and for each outcome variable, a multilevel, over-dispersed Poisson model was fit to the data. Outcome variables were the number of times the following behaviors occurred in the last 30 days: (1) having sex without a condom (2) injecting drugs (3) using unsterilized needles, and (4) sharing injection paraphernalia.

Results

Participants assigned to begin buprenorphine in the community experienced a greater decrease in injection drug use over time compared to participants assigned to begin buprenorphine in prison. There were no significant associations between treatment assignment or community treatment entry and instances of having sex without a condom, sharing injection paraphernalia, or using unsterilized needles.

Conclusions

Overall, the present study did not find support for the initiation of buprenorphine in prison (as opposed to the community) as a means to reduce incidences of HIV-risk behaviors. Avenues for future research in the nexus of HIV-risk reduction, criminal justice, and pharmacotherapy are discussed.

Trial registration This study was supported by the National Institute on Drug Abuse (NIDA), Buprenorphine for Prisoners (PI: Kinlock; R01DA021579). ClinicalTrials.gov identifier: NCT 00574067

Correlates of take-home naloxone kit possession among people who use drugs in British Columbia: A cross-sectional analysis

INTRODUCTION

In response to North America's opioid crisis, access to naloxone has increased. However, our understanding of the correlates of possessing a naloxone kit is limited. This study seeks to determine the prevalence and correlates of kit possession among people who use drugs (PWUD) in British Columbia (BC) Canada.

METHODS

This analysis used cross-sectional survey data collected in 2018 from 27 harm reduction sites in BC. Descriptive statistics and Poisson regression with robust error variance were used to examine factors associated with naloxone kit possession.

RESULTS

Overall, 70.7% (n = 246) of the total sample (n = 348) reported having a naloxone kit. Having a kit was significantly associated with self-reported opioid use in comparison with non-opioid use (Adjusted Prevalence Ratio (APR): 2.39; 95% CI: 1.33-4.32). Those reporting 'injection' as their preferred drug administration method were also more likely to possess a kit compared to those that predominantly preferred inhalation, smoking, or snorting (APR: 2.39; 95% CI: 1.25-4.58). Urbanicity, age, gender, and having regular housing were not significantly associated with possessing a kit.

CONCLUSIONS

This study is the first to examine naloxone kit possession across geographies, including non-urban areas. Lower kit possession among those that preferred inhaling, smoking or snorting drugs may reflect misconceptions around overdose risk of non-injection drug administration. Our study supports the need for enhanced awareness around the risk of opioid overdose with non-injection administration and suggests a need for comprehensive public health messaging that aims to address overdose risk and response.

Opioid agonist treatment scale-up and the initiation of injection drug use: A dynamic modeling analysis

BACKGROUND

Injection drug use (IDU) is associated with multiple health harms. The vast majority of IDU initiation events (in which injection-naïve persons first adopt IDU) are assisted by a person who injects drugs (PWID), and as such, IDU could be considered as a dynamic behavioral transmission process. Data suggest that opioid agonist treatment (OAT) enrollment is associated with a reduced likelihood of assisting with IDU initiation. We assessed the association between recent OAT enrollment and assisting IDU initiation across several North American settings and used dynamic modeling to project the potential population-level impact of OAT scale-up within the PWID population on IDU initiation.

METHODS AND FINDINGS

We employed data from a prospective multicohort study of PWID in 3 settings (Vancouver, Canada [n = 1,737]; San Diego, United States [n = 346]; and Tijuana, Mexico [n = 532]) from 2014 to 2017. Site-specific modified Poisson regression models were constructed to assess the association between recent (past 6 month) OAT enrollment and history of ever having assisted an IDU initiation with recently assisting IDU initiation. Findings were then pooled using linear mixed-effects techniques. A dynamic transmission model of IDU among the general population was developed, stratified by known factors associated with assisting IDU initiation and relevant drug use behaviors. The model was parameterized to a generic North American setting (approximately 1% PWID) and used to estimate the impact of increasing OAT coverage among PWID from baseline (approximately 21%) to 40%, 50%, and 60% on annual IDU initiation incidence and corresponding PWID population size across a decade. From Vancouver, San Diego, and Tijuana, respectively, 4.5%, 5.2%, and 4.3% of participants reported recently assisting an IDU initiation, and 49.4%, 19.7%, and 2.1% reported recent enrollment in OAT. Recent OAT enrollment was significantly associated with a 45% lower likelihood of providing recent IDU initiation assistance among PWID (relative risk [RR] 0.55 [95% CI 0.36-0.84], p = 0.006) compared to those not recently on OAT. Our dynamic model predicts a baseline mean of 1,067 (2.5%-97.5% interval [95% I 490-2,082]) annual IDU initiations per 1,000,000 individuals, of which 886 (95% I 406-1,750) are assisted by PWID. Based on our observed statistical associations, our dynamic model predicts that increasing OAT coverage from approximately 21% to 40%, 50%, or 60% among PWID could reduce annual IDU initiations by 11.5% (95% I 2.4-21.7), 17.3% (95% I 5.6-29.4), and 22.8% (95% I 8.1-36.8) and reduce the PWID population size by 5.4% (95% I 0.1-12.0), 8.2% (95% I 2.2-16.9), and 10.9% (95% I 3.2-21.8) relative to baseline, respectively, in a decade. Less impact occurs when the protective effect of OAT is diminished, when a greater proportion of IDU initiations are unassisted by PWID, and when average IDU career length is longer. The study's main limitations are uncertainty in the causal pathway between OAT enrollment and assisting with IDU initiation and the use of a simplified model of IDU initiation.

CONCLUSIONS

In addition to its known benefits on preventing HIV, hepatitis C virus (HCV), and overdose among PWID, our modeling suggests that OAT scale-up may also reduce the number of IDU initiations and PWID population size.

The Emerging Role of Inhaled Heroin in the Opioid Epidemic: A Review

Importance

Opioid addiction affects approximately 2.4 million Americans. Nearly 1 million individuals, including a growing subset of 21 000 minors, abuse heroin. Its annual cost within the United States amounts to $51 billion. Inhaled heroin use represents a global phenomenon and is approaching epidemic levels east of the Mississippi River as well as among urban youth. Chasing the dragon (CTD) by heating heroin and inhaling its fumes is particularly concerning, because this method of heroin usage has greater availability, greater ease of administration, and impressive intensity of subjective experience (high) compared with sniffing or snorting, although it also has a safer infectious profile compared with heroin injection. This is relevant owing to peculiar and often catastrophic brain complications. Following the American Medical Association Opioid Task Force mandate, we contribute a description of the pharmacology, pathophysiology, clinical spectrum, neuroimaging, and neuropathology of CTD leukoencephalopathy, as distinct from other heroin abuse modalities.

Observations

The unique spectrum of CTD-associated health outcomes includes an aggressive toxic leukoencephalopathy with pathognomonic neuropathologic features, along with sporadic instances of movement disorders and hydrocephalus. Clinical CTD severity is predominantly moderate at admission, frequently unmodified at discharge, and largely improved in the long term. Mild cases survive with minor sequelae, while moderate to severe presentations might deteriorate and progress to death. Other methods of heroin use may complicate with stroke, seizure, obstructive hydrocephalus, and (uncharacteristically) leukoencephalopathy.

Conclusions and Relevance

The distinct pharmacology of CTD correlates with its specific clinical and radiological features and prompts grave concern for potential morbidity and long-term disability costs. Proposed diagnostic criteria and standardized reporting would ameliorate the limitations of CTD literature and facilitate patient selection for a coenzyme Q10 therapeutic trial.

Foot drop with a popliteal artery aneurysm due to heroin use: A case report

Drug addiction has become an important problem worldwide, and the number of heroin users has been rapidly increasing. There are serious complications related to intravenous drug use. Sharing injectors and using them multiple times cause septic and infective complications. Another important aspect of intravenous drug use is that it potentiates vascular damage. Contaminated injectors may induce pseudoaneurysms when applied directly into the vessel, endothelium, or surrounding tissues. Infected pseudoaneurysms may provoke necrosis, rupture, bleeding, and some dramatic results such as loss of extremity or death. Herein, we report a female case who had a history of long-term substance abuse in whom foot drop developed with a popliteal artery aneurysm.

Heroin and healthcare: patient characteristics and healthcare prior to overdose

OBJECTIVES

To estimate heroin overdose trends among insured individuals and characterize patients and healthcare utilization preceding overdose to inform scale-up of effective prevention and treatment.

STUDY DESIGN

Retrospective descriptive analysis.

METHODS

We analyzed 2010 to 2014 IBM MarketScan Databases and calculated annual heroin overdose rates. For a subset of patients, we describe their comorbidities, where they accessed health services, and select prescription histories prior to their first heroin overdose.

RESULTS

Heroin overdose rates were much lower, but increased faster, among the commercially insured compared with Medicaid enrollees from 2010 to 2014 (270.0% vs 94.3%). By 2012, rates among the commercially insured aged 15 to 24 years reached the overall rates in the Medicaid population. All patients had healthcare encounters in the 6 months prior to their first heroin overdose; two-thirds of commercially insured patients had outpatient visits, whereas two-thirds of Medicaid patients had emergency department visits. One month prior to overdose, 24.5% of Medicaid and 8.6% of commercially insured patients had opioid prescriptions. Fewer Medicaid patients had buprenorphine prescriptions (17.8% vs 27.3%) despite similar rates of known substance-related disorders. A higher proportion of Medicaid patients had non-substance-related comorbidities.

CONCLUSIONS

Heroin overdose rates were persistently higher among the Medicaid population than the commercially insured, with the exception of those aged 15 to 24 years. Our findings on healthcare utilization, comorbidities, and where individuals access services could inform interventions at the point of care prior to a first heroin overdose. Outpatient settings are of particular importance for the growing cohort of young, commercially insured patients with opioid use disorders.

Gang Involvement and Drug Use Histories Among People Who Inject Drugs in California: A Retrospective Analysis

We examined whether gang membership history was associated with earlier age of first drug use, first drug injection, and shorter time to injection (TTI) drug use among people who inject drugs (PWID). PWID ( N = 438) were interviewed in California (2011-2013). Surveys addressed demographics, current/former drug use practices, gang membership, and parental drug use. Multivariate analyses were conducted to identify whether gang membership history was associated with age at first drug use, first injection drug use, and TTI. Gang membership was reported by 23% of sample. Gang membership history was associated with earlier ages of first drug use (–1.35 years; 95% confidence interval [CI]= [−0.50, −2.20]), age at first injection (–1.89 years; 95% CI = [0.00, −3.78]), but not TTI. Gang involvement facilitates drug use including earlier age of first injection drug use.

Factors Associated with Frequency of Recent Initiation of Others into Injection Drug Use Among People Who Inject Drugs in Los Angeles and San Francisco, CA, USA, 2016-17

Objective: Drug injection initiation is often assisted by a person who injects drugs (PWID). How often PWID provide this assistance has not been examined. We examine frequency of injection initiation assistance and factors associated with high (4+) and low frequency (1-3) initiation assistance as compared to no initiation assistance among PWID. Methods: Participants were 979 Californian PWID. PWID were interviewed about providing injection initiation assistance in the last 6 months among other items. Multinomial regression analysis was used to examine factors associated with levels of frequency of injection initiation assistance. Results: Among participants, 132 (14%) had initiated 784 people into injection (mean = 5.94 [standard deviation = 20.13]; median = 2, interquartile range = 1,4) in the last 6 months. PWID engaged in high frequency initiation (26% of sample) assisted 662 new initiates (84% of total). Using multinomial regression analysis with no initiating as the referent group, we found that high frequency initiating was statistically associated with higher injection frequency, having a paying sex partner, taking someone to a shooting gallery, and providing injection assistance. Lower frequency initiation was statistically associated with having a paying sex partner, illegal income source, and providing injection assistance. Conclusion: Differences between high and low frequency initiators were not found. Sex work and assisting with drug injection were linked to initiating others. Individual-level interventions that reduce this behavior among PWID and structural interventions such as safe consumption sites and opioid medication treatments that interrupt the social process of injection initiation should be considered as ways to reduce injection initiations.

Rising role of prescription drugs as a portal to injection drug use and associated mortality in Baltimore, Maryland

INTRODUCTION

Prescription drug abuse is a major public health problem in rural and suburban areas of the United States, however its emergence in large urban settings with endemic injection drug use remains understudied. We examined temporal trends in injection drug use initiation and mortality among people who inject drugs (PWID) in Baltimore, Maryland.

METHODS

Data were derived from the baseline assessment of PWID enrolled in a community-based cohort study with longitudinal follow-up for mortality assessment. PWID were recruited from 2005-2008 (N = 1,008) and 2015-2018 (N = 737). We compared characteristics by birth cohort (before/after 1980) and type of drug initiated (prescription opioids, prescription non-opioids, non-injection illicit drugs, or injection drugs). We calculated standardized mortality ratios (SMR) using the US general population as the reference.

RESULTS

PWID born after 1980 were more likely to initiate drug use with prescription opioids and non-opioids and had higher levels of polysubstance prior to injection initiation, compared to individuals born before 1980. Overall mortality was high: 2.59 per 100 person-years (95% CI: 2.27-2.95 per 100 person-years). Compared to the US population, the highest SMRs were observed among participants between 40-44 years of age, with especially high mortality among women in this age group (SMR:29.89, 95% CI: 15.24-44.54).

CONCLUSIONS

Mirroring national trends, the profile of PWID in Baltimore has changed with increased prescription drug abuse and high levels of polysubstance use among younger PWID. Interventions need to reach those using prescription drugs early after initiation of use in order to reduce transition to injecting. Urgent attention is warranted to address premature mortality, particularly among middle-aged and female PWID.

Age of Initiation and Patterns of Use among People Who Inject Drugs Welcomed in Harm Reduction Facilities in France from 2006 to 2015

This exploratory analysis of time-series cross-sectional data provides insights on trends in age at first injection among people who inject drugs in France, and on associations with recent risky injecting behaviors. Data were collected from a national survey conducted in harm reduction facilities in five phases between 2006 and 2015. Standardized questionnaires collected information on demographics, substance use, and route of administration, as well as lifetime and past-month injection. Descriptive and multilevel models were applied to account for the hierarchical structure of the data. Prevalence of lifetime and past-month injection remained stable over time, while the prevalence of daily injection increased significantly. Mean age at first injection only appeared to increase for data collected after 2010. Gender differences in mean age at first injection decreased over time, suggesting the development of converging patterns of initiation independent of sex. After controlling for covariates, early initiation of injection was unrelated to daily injection or material sharing, and associated with the number of recently injected substances. Early initiation is likely a predictor of injected polysubstance use. Findings are relevant to the planning, implementation, and evaluation of prevention programs.

Glecaprevir/pibrentasvir in patients with chronic HCV and recent drug use: An integrated analysis of 7 phase III studies

BACKGROUND

Injection drug use is the primary mode of transmission for hepatitis C virus (HCV), and treatment guidelines recommend treating HCV-infected people who use drugs; however, concerns about adherence, effectiveness, and reinfection have impeded treatment uptake.

METHODS

Data were pooled from seven phase III trials that evaluated the efficacy and safety of 8 or 12 weeks of glecaprevir/pibrentasvir (G/P) in patients chronically infected with HCV genotypes 1-6. Patients had compensated liver disease, with or without cirrhosis, and were HCV treatment-naïve or -experienced with interferon or pegylated interferon ± ribavirin, or sofosbuvir plus ribavirin ± pegylated interferon. Patients were grouped into recent drug users (injection drug use ≤12 months before screening, positive urine drug screen [UDS], and/or drug-related adverse event), former drug users (>12 months before screening and negative UDS), or non-drug users. Assessments included sustained virologic response at 12 weeks posttreatment (SVR12), treatment adherence, and safety.

RESULTS

Among 1819 patients, 5%, 34%, and 61% were recent, former, and non-drug users, respectively. Treatment adherence and completion were high (≥96%) regardless of drug use status. SVR12 was achieved by 93% (n/N = 91/98), 97% (n/N = 591/610), and >99% (n/N = 1106/1111) of recent, former, and non-drug users, respectively (intention-to-treat analysis). The overall rates of virologic failure were ≤1.5% across all three subpopulations, with no HCV reinfections among recent drug users. Drug-related serious adverse events and adverse events leading to treatment discontinuation were experienced by ≤1% of patients.

CONCLUSIONS

G/P is a well-tolerated and efficacious pangenotypic regimen for chronic HCV-infected people with recent or active drug use.