Contemporary cocaine use patterns and associated harms in Melbourne and Sydney, Australia

Low Risk of Cardiac Complications During Long-Term Follow-Up of Opioid Dependence

OBJECTIVES

To prospectively assess rates of QT prolongation, arrhythmia, syncope, and sudden cardiac death (SCD) in a cohort of people with heroin dependence.

METHODS

To estimate rates of QT prolongation, arrhythmia, and syncope, a subcohort (n = 130) from the Australian Treatment Outcomes Study, a prospective longitudinal cohort study of 615 people with heroin dependence, underwent medical history, venepuncture, and ECG at the 18- to 20-year follow-up.To estimate rates of SCD, probabilistic matching for the entire cohort was undertaken with the Australian Institute of Health and Welfare National Death Index. Deaths were classified into suicide, accidental overdose, trauma, unknown, and disease, which were then further subclassified by probability of SCD. SCD rate was the number of possible or probable SCDs divided by total patient years from the cohort.

RESULTS

From the subcohort, 4 participants (3%) met the criteria for QT prolongation; 3 were prescribed methadone. Seven participants (5%) reported history of arrhythmia, including 2 transferred from methadone to buprenorphine. Thirty participants (23%) reported a previous syncopal event-14 diagnosed as nonarrhythmic syncope and 13 not investigated. In the previous 12 months, 66 participants (51%) reported heroin use; 55 participants (42%) were prescribed methadone. No participant had QTc greater than 500 milliseconds.There were 3 possible SCDs, translating to an estimated SCD rate of 0.29 (CI: 0.05, 0.8) events per 1000 patient years. More cohort members died of overdose (n = 50), suicide (n = 11), and hepatitis C (n = 4).

CONCLUSIONS

Low rates of QT prolongation, arrhythmia, syncope, and SCD in the cohort despite high rates of heroin use and methadone treatment.

Trends in cocaine use, markets and harms in Australia, 2003-2019

INTRODUCTION

This paper aims to describe cocaine use, markets and harms in Australia from 2003 to 2019.

METHODS

Outcome indicators comprised prevalence of use from triennial household surveys; patterns of use from annual surveys of sentinel samples who use stimulants; and cocaine-related seizures, arrests, hospitalisations, deaths and treatment episodes. Bayesian autoregressive time-series analyses were conducted to estimate trend over time: Model 1, no change; Model 2, constant rate of change; and Model 3, change over time differing in rate after one change point.

RESULTS

Past-year population prevalence of use increased over time. The percentage reporting recent use in sentinel samples increased by 6.1% (95% credible interval [CrI_95% ] 1.2%,16.9%; Model 3) per year from around 2017 (48%) until the end of the series (2019: 67%). There was a constant annual increase in number of seizures (count ratio: 1.1, CrI_95% 1.1,1.2) and arrests (1.2, CrI_95% 1.1,1.2), and percentage reporting cocaine as easy to obtain in the sentinel samples (percent increase 1.2%, CrI_95% 0.5%,1.8%; Model 2). Cocaine-related hospitalisation rate increased from 5.1 to 15.6 per 100 000 people from around 2011-2012 to 2017-2018: an annual increase of 1.3 per 100 000 people (CrI_95% 0.8,1.8; Model 3). While the death rate was low (0.23 cocaine-related deaths per 100 000 people in 2018; Model 2), treatment episodes increased from 3.2 to 5.9 per 100 000 people from around 2016-2017 to 2017-2018: an annual increase of 2.9 per 100 000 people (CrI_95% 1.6,3.7; Model 3).

DISCUSSION AND CONCLUSIONS

Cocaine use, availability and harm have increased, concentrated in recent years, and accompanied by increased treatment engagement.

Polydrug Use and Heterogeneity in HIV Risk Among People Who Inject Drugs in Estonia and Russia: A Latent Class Analysis

Non-medical drug injection is a major risk factor for HIV infection in Russia and Estonia. Multiple drug use (polydrug) has further been associated with increased harms. We compared HIV, injecting and sexual risk associated with polydrug use among people who injected drugs (PWID) in 2012–2013 in Kohtla-Järve (Estonia, n = 591) and St Petersburg (Russia, n = 811). Using latent class analysis, we identified five (poly)drug classes, the largest consisting of single-drug injectors among whom an opioid was the sole drug injected (56% of PWID). The four remaining polydrug classes included polydrug-polyroute injectors who injected and used opiates and stimulants (9%), opiate-stimulant poly-injectors who injected amphetamine-type-stimulants with a primary opiate (7%) and opiate-opioid poly-injectors who injected opioids and opiates (16%). Non-injection stimulant co-users were injectors who also used non-injection stimulants (12%). In multivariable multinomial regressions, all four polydrug classes were associated with greater injection risks than single-drug injection, while opiate-stimulant and opiate-opioid poly-injection were also associated with having multiple sex partners. Riskier behaviours among polydrug-injectors suggest increased potential for transmission of blood-borne and sexually-transmitted infections. In addition to needles/syringes provision, services tailored to PWID drug and risk profiles, could consider drug-appropriate treatment and sexual risk reduction strategies to curb HIV transmission.

Realising the technological promise of smartphones in addiction research and treatment: An ethical review

BACKGROUND

Smartphone technologies and mHealth applications (or apps) promise unprecedented scope for data collection, treatment intervention, and relapse prevention when used in the field of substance abuse and addiction. This potential also raises new ethical challenges that researchers, clinicians, and software developers must address.

AIMS

This paper aims to identify ethical issues in the current uses of smartphones in addiction research and treatment.

METHODS

A search of three databases (PubMed, Web of Science and PsycInfo) identified 33 studies involving smartphones or mHealth applications for use in the research and treatment of substance abuse and addiction. A content analysis was conducted to identify how smartphones are being used in these fields and to highlight the ethical issues raised by these studies.

RESULTS

Smartphones are being used to collect large amounts of sensitive information, including personal information, geo-location, physiological activity, self-reports of mood and cravings, and the consumption of illicit drugs, alcohol and nicotine. Given that detailed information is being collected about potentially illegal behaviour, we identified the following ethical considerations: protecting user privacy, maximising equity in access, ensuring informed consent, providing participants with adequate clinical resources, communicating clinically relevant results to individuals, and the urgent need to demonstrate evidence of safety and efficacy of the technologies.

CONCLUSIONS

mHealth technology offers the possibility to collect large amounts of valuable personal information that may enhance research and treatment of substance abuse and addiction. To realise this potential researchers, clinicians and app-developers must address these ethical concerns to maximise the benefits and minimise risks of harm to users.

Predictors of change in cocaine use in a street-recruited cohort of young cocaine users

AIM

To determine predictors of changes in amount of cocaine use among regular users outside treatment services.

DESIGN

Longitudinal study-we estimated the proportion of subjects who increased or decreased cocaine use and assessed possible predictors related to these changes among a street-recruited cohort of young regular cocaine users (RCU).

SETTING

Three Spanish cities: Barcelona, Madrid and Seville

PARTICIPANTS

A total of 720 RCU aged 18-30 years not regularly using heroin were recruited in the community during 2004-06 (Itinere Project). Follow-up interviews (n = 501) were carried out at 12-24 months.

MEASUREMENTS

The average amount of cocaine used weekly was calculated taking into account the number of days of use and the usual quantity (g/day). A multinomial logistic regression approach was used to investigate the association between changes in amount of cocaine use (i.e. difference exceeded 33.3% of baseline level) after 12-24 months, and baseline socio-demographic characteristics, nightlife, patterns of cocaine use and use of alcohol and other psychoactive drugs.

FINDINGS

Cocaine use baseline average level was 2.14 g/week [95% confidence interval (CI) = 2.02-2.42]. It decreased in 71.5% of subjects and increased in 14.1%. In multinomial analysis, negative associations were found between decreasing cocaine use and high levels of alcohol consumption and using an increasing number of psychoactive drugs. Moreover, low education level, having used cocaine frequently in houses and reporting cocaine binges were associated with increasing cocaine use.

CONCLUSIONS

A street-recruited cohort of cocaine users in Spain showed a significant reduction in cocaine use over a period of 12-24 months. High consumption of alcohol and increasing use of other psychoactive drugs decreased the probability of reducing cocaine use.

Use of Silk Road, the online drug marketplace, in the United Kingdom, Australia and the United States

AIMS

To investigate the prevalence of awareness of the online illicit drug marketplace Silk Road (SR), consumption of drugs purchased from SR and reasons for use and non-use of SR.

DESIGN AND SETTING

Global Drug Survey: purposive sample collected in late 2012.

PARTICIPANTS

The base sample (n = 9470) reported recent drug purchase and resided in the United Kingdom (n = 4315, median age 24, 76% male), Australia (n = 2761, median age 32, 76% male) or the United States (n = 2394, median age 21, 80% male).

MEASUREMENTS

Online questionnaire.

FINDINGS

A total of 65% of US, 53% of Australian and 40% of UK respondents had heard of SR; 18% of US, 10% of UK and 7% of Australian respondents had consumed drugs purchased through SR. Across the three countries, 3,4-methylenedioxy-N-methylamphetamine (MDMA) was the most commonly purchased drug (53-60%), followed by cannabis (34-51%), lysergic acid diethylamide (LSD) (29-45%) and the 2C family (16%-27%). The most common reasons for purchasing from SR were wider range (75-89%), better quality (72-77%), greater convenience (67-69%) and the use of vendor rating systems (60-65%). The most common reasons for avoiding SR purchase were adequate drug access (63-68%) and fear of being caught (41-53%). Logistic regressions found that, compared with people from the UK, Australians [odds ratio (OR) = 3.37; 95% confidence interval (CI) = 2.29, 4.97) and Americans (OR = 1.46; 95% CI = 1.10, 1.94) were more likely to use SR due to lower prices; and to avoid SR purchase due to fear of being caught (Australia: OR = 1.65; 95% CI = 1.39, 1.96; USA: OR = 1.62; 95% CI = 1.37, 1.92).

CONCLUSIONS

While reasons for Silk Road use accord with broader online commerce trends (range, quality, convenience, ratings), its appeal to drug purchasers is moderated by country-specific deterrents and market characteristics.

Distinctive personality traits and neural correlates associated with stimulant drug use versus familial risk of stimulant dependence

BACKGROUND

Stimulant drugs such as cocaine and amphetamine have a high abuse liability, but not everyone who uses them develops dependence. However, the risk for dependence is increased for individuals with a family history of addiction. We hypothesized that individuals without a family history of dependence who have been using cocaine recreationally for several years but have not made the transition to dependence will differ in terms of personality traits and brain structure from individuals who are either dependent on stimulants or at risk for dependence.

METHODS

We compared 27 individuals without a familial risk of dependence who had been using cocaine recreationally with 50 adults with stimulant dependence, their nondependent siblings (n = 50), and unrelated healthy volunteers (n = 52) who had neither a personal nor a family history of dependence. All participants underwent a magnetic resonance imaging brain scan and completed a selection of personality measures that have been associated with substance abuse.

RESULTS

Increased sensation-seeking traits and abnormal orbitofrontal and parahippocampal volume were shared by individuals who were dependent on stimulant drugs or used cocaine recreationally. By contrast, increased levels of impulsive and compulsive personality traits and limbic-striatal enlargement were shared by stimulant-dependent individuals and their unaffected siblings.

CONCLUSIONS

We provide evidence for distinct neurobiological phenotypes that are either associated with familial vulnerability for dependence or with regular stimulant drug use. Our findings further suggest that some individuals with high sensation-seeking traits but no familial vulnerability for dependence are likely to use cocaine but may have relatively low risk for developing dependence.

Effect of prison-based opioid substitution treatment and post-release retention in treatment on risk of re-incarceration

AIMS

People who use heroin are frequently incarcerated multiple times. Reducing re-incarceration of this group is important for reducing both health risks associated with incarceration and the costs of correctional administration. Opioid substitution treatment (OST) in prisons may help to reduce re-incarceration, but research findings on this topic have been mixed. In this study, we examined the effect of OST in prison and after release on re-incarceration.

DESIGN

Longitudinal cohort study. SETTING, PARTICIPANTS AND MEASUREMENTS: Data on OST and incarceration were linked for a cohort of 375 male heroin users recruited originally in prisons in New South Wales, Australia. Data were linked for the period 1 June 1997-31 December 2006. Re-incarceration was examined using recurrent-event survival analysis models. Model 1 examined the effect of OST status at release from prison (i.e. in treatment versus out of treatment on the day of release) on re-incarceration. Model 2 considered the effect of remaining in OST after release on risk of re-incarceration.

FINDINGS

Ninety per cent of participants were re-incarcerated following their first observed release. Pre-incarceration cocaine use was associated with a 13% increase in the average risk of re-incarceration. There was no significant association between simply being in OST at the time of release and risk of re-incarceration; however, in the model taking into account post-release retention in treatment, the average risk of re-incarceration was reduced by 20% while participants were in treatment.

CONCLUSIONS

In New South Wales, Australia, opioid substitution treatment after release from prison has reduced the average risk of re-incarceration by one-fifth.

Mortality among cocaine users: a systematic review of cohort studies

AIMS

To conduct a systematic review of mortality among cohort studies of cocaine users.

METHODS

Three electronic databases were searched (EMBASE, Medline and PsychINFO); other online databases were searched using online libraries and repositories of reports and literature in the drug and alcohol field, with requested contributions from trained librarians and experts. Searches and extraction were undertaken using protocols and cross-checking of decisions by two authors. Additional data were requested from study investigators where studies did not report relevant data.

RESULTS

1911 articles and 2 reports were identified from searches, with data from another four studies located from review articles. Seven cohorts of "problem" or dependent cocaine users reported data that permitted mortality rates to be estimated. Crude mortality rates ranged from 0.53 (95% CI: 0.10-1.58) to 6.16 (95% CI: 5.21-7.11) per 100 PY. Standardised mortality ratios (SMRs) reported in four studies suggested that mortality was four to eight times higher among cocaine users than age and sex peers in the general population.

CONCLUSIONS

There are limited data on the extent of elevated mortality among problematic or dependent cocaine users and it is unclear how generalisable the results of these studies may be to other populations of problematic cocaine users. Greater attention to both the method of recruitment, and the characteristics of cocaine users, would enhance our understanding of the mortality risks of problematic cocaine use.

A cost-effectiveness analysis of modafinil therapy for psychostimulant dependence

INTRODUCTION AND AIMS

To examine the cost-effectiveness of modafinil (200 mg daily) plus counselling compared with placebo for the treatment of psychostimulant dependence.

DESIGN AND METHODS

Cost and outcome data were collected alongside two randomised controlled trials of modafinil 200 mg daily over 10 weeks for methamphetamine (n = 74) and cocaine dependence (n = 8), respectively. Incremental cost-effectiveness ratios representing the additional costs to achieve a given outcome were calculated for both the change in the number of stimulant-free days and quality-adjusted life years 12 weeks post-treatment.

RESULTS

The incremental cost-effectiveness ratio indicated that it would cost an additional $AUD79 to achieve an extra stimulant-free day with modafinil compared with placebo. This result was not statistically significant, but appeared to be a robust estimate after sensitivity analysis. Counselling, whether received within program or from other services, improved the cost-effectiveness of modafinil relative to placebo.

DISCUSSION AND CONCLUSIONS

Strategies to improve the uptake of counselling are recommended as cost-effective.

Injecting equipment sharing in Russian drug injecting dyads

In this study, we investigated how individual attributes, dyad characteristics and social network characteristics may influence engaging in receptive syringe sharing, distributive syringe sharing and sharing cookers in injecting partnerships of IDUs in St Petersburg, Russia. We found that all three levels were associated with injecting equipment sharing, and that dyad characteristics were modified by characteristics of the social network. Self-reported HIV discordance and male gender concordance played a role in the risk of equipment sharing. Dyad interventions may not be sufficient to reduce injecting risk in IDU partnerships, but a combination of dyad and network interventions that target both IDU partnerships and the entire IDU population may be more appropriate to address injecting risk among IDUs.