Correlates of illicit methadone use in New York City: a cross-sectional study

Comparing presumptive with direct-to-definitive drug testing in oral fluid vs. urine for a U.S. national sample of individuals misusing drugs

BACKGROUND

The aims are to compare the results of presumptive drug testing with confirmation of positives vs. direct-to-definitive drug testing, combined with investigation of urine vs. oral fluid as test matrices.

METHODS

Paired oral fluid and urine specimens were collected voluntarily and anonymously from 1098 individuals applying for methadone treatment in 11 clinics across 7 U.S. states. All specimens were analyzed by immunoassay (IA) and liquid chromatography-tandem mass spectrometry (LC-MS-MS).

RESULTS

Confirmed IA prevalences for urine were significantly higher than for oral fluid for 7 out of 10 drug classes - benzodiazepines, cannabis, cocaine, methadone, opiates, oxycodone and tramadol. Drug prevalences by direct-to-definitive LC-MS-MS were either the same or higher than prevalences by confirmed IA. Drug prevalences by LC-MS-MS were higher in urine for two drug classes (cocaine, methadone) and higher in oral fluid for two drug classes (buprenorphine, tramadol), but were equivalent in urine and oral fluid when averaged over all 10 drug classes. Certain drugs of special concern such as heroin and buprenorphine were more frequently detected in oral fluid than urine.

CONCLUSIONS

Urine analysis showed some technical advantage over oral fluid in sensitivity to several drug classes within a confirmed IA testing protocol, but this may be outweighed if there is reason to believe that tampering with urine specimens is a significant problem. Overall drug detection by direct-to-definitive testing was similar for oral fluid and urine, but one matrix may be preferable if there is a particular drug of clinical or epidemiological interest.

Characteristics Associated with Nonmedical Methadone Use among People Who Inject Drugs in California

Background: Illicit, nonmedical use of opioid agonist medications such as methadone is an ongoing concern. Yet, few studies have examined nonmedical use of methadone by people who inject drugs (PWID). Objectives: This study describes the prevalence of nonmedical methadone use in a community sample of PWID and examines factors associated with recent use of nonmedical methadone. Methods: A cross-sectional sample of PWID (N = 777) was recruited using targeted sampling and interviewed in California (2011-2013). Descriptive, bivariate, and multivariate logistic regression analyses were used to determine characteristics associated with nonmedical methadone use in the last 30 days. To determine if nonmedical methadone use was associated with overdose in the last 6 months, a separate multivariate analysis was conducted. Results: Among PWID sampled, 21% reported nonmedical methadone use in the last 30 days. In multivariate logistic regression analysis, nonmedical methadone use was associated with recent methadone maintenance treatment (adjusted odds ratio [AOR] = 2.86; 95% confidence interval [CI] = 1.90, 4.30), recent nonmedical buprenorphine use (AOR = 3.12; 95% CI = 1.31, 7.47), higher injection frequency (referent <30 injections; 30-89 injections AOR = 1.89; 95% CI = 1.19, 3.02; 90-plus injections AOR = 2.43; 95% CI = 1.53, 3.87), schizophrenia diagnosis (AOR = 2.36; 95% CI = 1.36, 4.10), recent non-injection opioid prescription use (AOR = 2.97; 95% CI = 1.99, 4.43), and recent injection opioid prescription misuse (AOR = 2.13; 95% CI = 1.27, 3.59). Nonmedical methadone use was found not to be associated with nonfatal overdose (AOR = 0.77; 95% CI = 0.38, 1.56). Conclusion: Nonmedical methadone use identifies a vulnerable subpopulation among PWID, is not associated with elevated nonfatal overdose risk, and evidences a need to expand methadone treatment availability.

Non-prescribed use of methadone and buprenorphine prior to opioid substitution treatment: lifetime prevalence, motives, and drug sources among people with opioid dependence in five Swedish cities

BACKGROUND

Opioid substitution treatment (OST) with methadone or buprenorphine is the most effective means of treating opioid dependence. If these substances are used by people who are not undergoing OST, they can however carry serious risks. This article examines the lifetime prevalence, motives, and drug sources for such use, as well as geographical differences in these variables.

METHODS

Structured interviews were conducted with 411 patients from 11 OST clinics in five Swedish cities. The researchers carried out 280 interviews on-site, while 131 interviews were conducted by specially trained patients through privileged access interviewing. Data were analyzed by frequency and average calculations, cross-tabulations, and χ2 tests.

RESULTS

The lifetime prevalence of non-prescribed use was 87.8% for methadone, 80.5% for buprenorphine, and 50.6% for buprenorphine/naloxone. Pseudo-therapeutic motives-avoiding withdrawal symptoms, staying clean from heroin, detoxification, or taking care of one's own OST-were commonly cited as driving the use, while using the drugs for euphoric purposes was a less common motive. Most respondents had bought or received the substances from patients in OST, but dealers were also a significant source of non-prescribed methadone and buprenorphine. Geographical differences of use, motives, and sources suggest that prescription practices in OST have a great impact on which substances are used outside of the treatment.

CONCLUSIONS

Experiences of non-prescribed use of methadone and buprenorphine are extremely common among those in OST in southern Sweden. As the use is typically driven by pseudo-therapeutic motives, increased access to OST might decrease the illicit demand for these substances. Buprenorphine/naloxone has a lower abuse potential than buprenorphine and should therefore be prioritized as the prescribed drug. Supervised dosage and other control measures are important provisions in the prevention of drug diversion and non-prescribed use among people not undergoing OST.

Depression and smoking characteristics among HIV-positive smokers in Russia: A cross-sectional study

INTRODUCTION

Globally, persons with HIV infection, depression and substance use disorders have a higher smoking prevalence and smoke more heavily than other populations. These associations have not been explored among Russian smokers with HIV infection and substance use disorders. The purpose of this study was to examine the relationship between the presence of depressive symptoms and smoking outcomes in an HIV-positive cohort of Russian smokers with a history of substance use disorders (alcohol and/or drug use disorders).

METHODS

We performed a cross-sectional secondary data analysis of a cohort of HIV-positive regular smokers with a history of substance use disorders recruited in St. Petersburg, Russia in 2012-2015. The primary outcome was heavy smoking, defined as smoking > 20 cigarettes per day. Nicotine dependence (moderate-very high) was a secondary outcome. The main independent variable was a high level of depressive symptoms in the past 7 days (defined as CES-D > = 24). We used multivariable logistic regression to examine associations between depressive symptoms and the outcomes, controlling for age, sex, education, income, running out of money for housing/food, injection drug use, and alcohol use measured by the AUDIT.

RESULTS

Among 309 regular smokers, 79 participants (25.6%) had high levels of depressive symptoms, and 65 participants (21.0%) were heavy smokers. High levels of depressive symptoms were not significantly associated with heavy smoking (adjusted odds ratio [aOR] 1.50, 95% CI 0.78-2.89) or with moderate-very high levels of nicotine dependence (aOR 1.35, 95% CI 0.75-2.41).

CONCLUSIONS

This study did not detect an association between depressive symptoms and smoking outcomes among HIV-positive regular smokers in Russia.

Nonmedical opioid use and heroin use in a nationally representative sample of us high school seniors

BACKGROUND

Nonmedical use of opioids has become increasingly problematic in recent years with increases in overdoses, treatment admissions, and deaths. Use also appears to be contributing to heroin initiation, which has increased in recent years. Further research is needed to examine which adolescents are at highest risk for nonmedical use of opioids and heroin and to explore potential links between nonmedical opioid use and heroin use.

METHODS

Data were analyzed from a nationally representative sample of American high school seniors in the Monitoring the Future study (2009-2013, Weighted N=67,822). We examined associations between frequency and recency of nonmedical use of opioids and heroin. Sociodemographic correlates of use of each drug were also examined.

RESULTS

12.4% of students reported lifetime nonmedical opioid use and 1.2% reported lifetime heroin use. As frequency of lifetime nonmedical opioid use increased, so too did the odds for reporting heroin use, with over three-quarters (77.3%) of heroin users reporting lifetime nonmedical opioid use. Recent (30-day) nonmedical opioid use was a robust risk factor for heroin use and almost a quarter (23.2%) of students who reported using opioids ≥40 times reported lifetime heroin use. Black and Hispanic students were less likely to report nonmedical opioid or heroin use than white students, but they were more likely to report heroin use in absence of nonmedical opioid use.

DISCUSSION

Recent and frequent nonmedical opioid use are risk factors for heroin use among adolescents. Prevention needs to be targeted to those at highest risk.

The effect of prescription opioid injection on the risk of non-fatal overdose among people who inject drugs

OBJECTIVES

Prescription opioid (PO) use by people who inject drugs (PWID) is a growing public health concern. Non-fatal overdose remains a leading source of morbidity among PWID, however, little is known about the relationship between PO injection and non-fatal overdose in this population. In this study we sought to examine the impact of PO injection on non-fatal overdose among PWID from Vancouver, Canada.

METHODS

Data were derived from two open prospective cohorts of PWID for the period of December, 2005 to May, 2014. Multivariable generalized estimating equations were used to examine the odds of overdose among those who injected: POs; heroin; and POs and heroin.

RESULTS

In total, 1660 PWID (33.7% women) participated in this study. In multivariable analyses, in comparison to those who were injecting non-opioid drugs, exclusive PO injection was not significantly associated with non-fatal overdose (adjusted odds ratio [AOR]: 1.17, 95% confidence interval [CI]: 0.74-1.86). The odds of non-fatal overdose were elevated for heroin injection (AOR: 1.72, 95% CI: 1.31-2.27), but were greatest for those who injected both heroin and POs (AOR: 2.46, 95% CI: 1.83-3.30).

DISCUSSION

Compared to injecting non-opioids, injecting POs exclusively did not increase risk of non-fatal overdose; however, injecting both POs and heroin doubled the risk. This may reflect consistencies in drug potency and composition when POs are used, as well as unique characteristics of exclusive PO injectors. Our findings call for the continued scale-up of evidence-based overdose prevention interventions for people who inject opioids, including POs.

Factors associated with illicit methadone injecting in a Canadian setting

BACKGROUND AND OBJECTIVES

While methadone is well established as an evidence-based treatment for opioid use disorder, safety concerns persist regarding its diversion. The authors examine the prevalence of and risk factors associated with injection of methadone in an urban population.

METHODS

Between December 2005 and November 2013, data were derived from two open prospective studies of persons who inject drugs (PWID) in Vancouver, Canada. Generalized estimating equations (GEE) logistic regression was used to determine factors independently associated with illicit methadone injecting.

RESULTS

During the study, 1911 individuals (34% women) were recruited; 134 (7%) participants reported methadone injecting at least once. In multivariable analysis, Caucasian ethnicity [adjusted odds ratio (AOR) = 1.90, 95% confidence interval (CI) = 1.20-3.00]; homelessness (AOR = 1.46, 95% CI = 1.09-1.95); drug dealing (AOR = 2.10, 95% CI = 1.50-2.93); ≥daily heroin injection (AOR = 1.57, 95% CI = 1.08-2.26); ≥daily crack smoking (AOR = 2.06, 95% CI = 1.44-2.95); being a victim of violence (AOR = 1.48, 95% CI = 1.04-2.12); and non-fatal overdose (AOR = 1.67, 95% CI = 1.67 (1.00-2.79) were independently and positively associated with methadone injection; female gender (AOR = 0.47, 95% CI = 0.30-0.75) was negatively associated.

DISCUSSION AND CONCLUSIONS

The diversion of methadone for illicit injection in this urban setting was associated with several markers of addiction severity and other health and social vulnerabilities.

SCIENTIFIC SIGNIFICANCE

These findings underscore the need to ensure methadone accessibility while limiting diversion-related risk.

Diffusion and diversion of suboxone: an exploration of illicit street opioid selling

Interviews with fourteen opioid retail pill sellers provides an exploration into the diversion and diffusion of Suboxone to recreational ("week-end warriors") drug users. The use of social media and electronic devices enables the diffusion of Suboxone to dependent and non-dependent opiate/opioid drug abusers. Overprescribing by physicians and prescribing in drug treatment settings fuels the diversion of Suboxone. The diversion and the diffusion of Suboxone have the potential to delay entrance into drug treatment and promote the misuse of the drug by both dependent opiate/opioid drug abusers and recreational users. The dilemma posed by Suboxone maintenance treatment will not be easily addressed or mitigated in the near future.

Illicit use of opioid substitution drugs: prevalence, user characteristics, and the association with non-fatal overdoses

BACKGROUND AND AIMS

Diversion of opioid substitution drugs (OSD) is of public concern. This study examined the prevalence, frequency, and predictors of illicit OSD use in a group of injecting drug users (IDUs) and assessed if such use was associated with non-fatal overdoses.

METHODS

Semi-annual cross-sectional interviews conducted in Oslo, Norway (2006-2013), from 1355 street-recruited IDUs. Hurdle, logistic, and multinomial regression models were employed.

RESULTS

Overall, 27% reported illicit OSD use in the past four weeks; 16.8% methadone, 12.5% buprenorphine, and 2.9% both drugs. Almost 1/10 reported at least one non-fatal overdose in the past four weeks, and roughly 1/3 reported such experience in the past year. Use of additional drugs tended to be equally, or more prevalent among illicit OSD users than other IDUs. In terms of illicit OSD use being a risk factor for non-lethal overdoses, our results showed significant associations only for infrequent buprenorphine use (using once or less than once per week). Other factors associated with non-fatal overdoses included age, education, homelessness, as well as the benzodiazepines, stimulants, and heroin use.

CONCLUSIONS

Users of diverted OSD may represent a high-risk population, as they used more additional drugs and used them more frequently than other IDUs. However, illicit OSD use may be less harmful than previously assumed. After accounting for an extensive set of covariates, only infrequent illicit buprenorphine use, but not methadone use, was associated with non-fatal overdoses.

Factors associated with high-frequency illicit methadone use among rural Appalachian drug users

BACKGROUND

In recent years there has been a sharp increase in the use of illicit methadone as well as methadone-related overdose deaths.

OBJECTIVE

The purpose of this study was to describe factors associated with low- and high-frequency methadone use in a cohort of rural Appalachian drug users.

METHODS

Interviews assessing sociodemographics, illicit drug use and drug treatment, psychiatric disorders, health and sociometric drug network characteristics were conducted with 503 rural drug users between 2008 and 2010. A two-level mixed effects regression model was utilized to differentiate low- (one use per month or less in the past six months) versus high-frequency (daily or weekly use in the past six months) illicit methadone users.

RESULTS

The lifetime prevalence of illicit methadone use in this population was 94.7% (n = 476) and slightly less than half (46.3%) were high-frequency users. In the mixed effects regression model, initiating illicit methadone use at a younger age was associated with high-frequency illicit methadone use. Taking a prescribed medication for a physical problem, undergoing additional weeks of outpatient drug free treatment, daily OxyContin® use in the past month, and having fewer ties and second-order connections in the drug network reduced the odds of high-frequency illicit methadone use.

CONCLUSIONS

Rates of illicit methadone use and high-frequency illicit methadone use among this sample of rural drug users were considerably higher than those previously reported in the literature. Health practitioners in rural areas should routinely screen for illicit opioid use, including methadone.

Interaction between polygenic risk for cigarette use and environmental exposures in the Detroit Neighborhood Health Study

Cigarette smoking is influenced both by genetic and environmental factors. Until this year, all large-scale gene identification studies on smoking were conducted in populations of European ancestry. Consequently, the genetic architecture of smoking is not well described in other populations. Further, despite a rich epidemiologic literature focused on the social determinants of smoking, few studies have examined the moderation of genetic influences (for example, gene-environment interactions) on smoking in African Americans. In the Detroit Neighborhood Health Study (DNHS), a sample of randomly selected majority African American residents of Detroit, we constructed a genetic risk score (GRS), in which we combined top (P-value <5 × 10(-7)) genetic variants from a recent meta-analysis conducted in a large sample of African Americans. Using regression (effective n=399), we first tested for association between the GRS and cigarettes per day, attempting to replicate the findings from the meta-analysis. Second, we examined interactions with three social contexts that may moderate the genetic association with smoking: traumatic events, neighborhood social cohesion and neighborhood physical disorder. Among individuals who had ever smoked cigarettes, the GRS significantly predicted the number of cigarettes smoked per day and accounted for ~3% of the overall variance in the trait. Significant interactions were observed between the GRS and number of traumatic events experienced, as well as between the GRS and average neighborhood social cohesion; the association between genetic risk and smoking was greater among individuals who had experienced an increased number of traumatic events in their lifetimes, and diminished among individuals who lived in a neighborhood characterized by greater social cohesion. This study provides support for the utility of the GRS as an alternative approach to replication of common polygenic variation, and in gene-environment interaction, for smoking behaviors. In addition, this study indicates that environmental determinants have the potential to both exacerbate (traumatic events) and diminish (neighborhood social cohesion) genetic influences on smoking behaviors.

Opioid maintenance treatment as a harm reduction tool for opioid-dependent individuals in New York City: the need to expand access to buprenorphine/naloxone in marginalized populations

The aim of this pilot study was to assess the effectiveness of buprenorphine/naloxone (BUP/NX) among marginalized, opioid-dependent individuals in terms of retention in and cycling into and out of a harm-reduction program. This pilot study enrolled 100 participants and followed them from November 2005 to July 2008. The overall proportion of patients retained in the program at the end of 3, 6, 9, and 12 months was 68%, 63%, 56%, and 42%, respectively. This pilot study demonstrated that BUP/NX could be successfully used to treat marginalized heroin users.

Beyond income: material resources among drug users in economically-disadvantaged New York City neighborhoods

BACKGROUND

Little is known about material resources among drug users beyond income. Income measures can be insensitive to variation among the poor, do not account for variation in cost-of-living, and are subject to non-response bias and underreporting. Further, most do not include illegal income sources that may be relevant to drug-using populations.

METHODS

We explored the reliability and validity of an 18-item material resource scale and describe correlates of adequate resources among 1593 current, former and non-drug users recruited in New York City. Reliability was determined using coefficient α, ω(h), and factor analysis. Criterion validity was explored by comparing item and mean scores by income and income source using ANOVA; content validity analyses compared scores by drug use. Multiple linear regression was used to describe correlates of adequate resources.

RESULTS

The coefficient α and ω(h) for the overall scale were 0.91 and 0.68, respectively, suggesting reliability was at least adequate. Legal income >$5000 (vs. ≤$5000) and formal (vs. informal) income sources were associated with more resources, supporting criterion validity. We observed decreasing resources with increasing drug use severity, supporting construct validity. Three factors were identified: basic needs, economic resources and services. Many did not have their basic needs met and few had adequate economic resources. Correlates of adequate material resources included race/ethnicity, income, income source, and homelessness.

CONCLUSIONS

The 18-item material resource scale demonstrated reliability and validity among drug users. These data provide a different view of poverty, one that details specific challenges faced by low-income communities.

Opioid maintenance treatment as a harm reduction tool for opioid-dependent individuals in New York City: the need to expand access to buprenorphine/naloxone in marginalized populations

The aim of this pilot study was to assess the effectiveness of buprenorphine/naloxone (BUP/NX) among marginalized, opioid-dependent individuals in terms of retention in and cycling into and out of a harm-reduction program. This pilot study enrolled 100 participants and followed them from November 2005 to July 2008. The overall proportion of patients retained in the program at the end of 3, 6, 9, and 12 months was 68%, 63%, 56%, and 42%, respectively. This pilot study demonstrated that BUP/NX could be successfully used to treat marginalized heroin users.