Opioid overdose and the power of old myths: what we thought we knew, what we do know and why it matters

Prevalence of co-occurring mental illness and substance use disorder and association with overdose: a linked data cohort study among residents of British Columbia, Canada

AIMS

To estimate the treated prevalence of mental illness, substance use disorder (SUD) and dual diagnosis and the association between dual diagnosis and fatal and non-fatal overdose among residents of British Columbia (BC), Canada.

DESIGN

A retrospective cohort study using linked health, income assistance, corrections and death records.

SETTING

British Columbia (BC), Canada.

PARTICIPANTS

A total of 921 346 BC residents (455 549 males and 465 797 females) aged 10 years and older.

MEASUREMENTS

Hospital and primary-care administrative data were used to identify a history of mental illness only, SUD only, dual diagnosis or no history of SUD or mental illness (2010-14) and overdoses resulting in medical care (2015-17). We calculated crude incidence rates of non-fatal and fatal overdose by dual diagnosis history. Andersen-Gill and competing risks regression were used to examine the association between dual diagnosis and non-fatal and fatal overdose, respectively, adjusting for age, sex, comorbidities, incarceration history, social assistance, history of prescription opioid and benzodiazepine dispensing and region of residence.

FINDINGS

Of the 921 346 people in the cohort, 176 780 (19.2%), 6147 (0.7%) and 15 269 (1.7%) had a history of mental illness only, SUD only and dual diagnosis, respectively; 4696 (0.5%) people experienced 688 fatal and 6938 non-fatal overdoses. In multivariable analyses, mental illness only, SUD only and dual diagnosis were associated with increased rate of non-fatal [hazard ratio (HR) = 1.8, 95% confidence interval (CI) = 1.6-2.1; HR = 9.0, 95% CI = 7.0-11.5, HR = 8.7, 95% CI = 6.9-10.9, respectively] and fatal overdose (HR = 1.6, 95% CI = 1.3-2.0, HR = 4.3, 95% CI = 2.8-6.5, HR = 4.1, 95% CI = 2.8-6.0, respectively) compared with no history.

CONCLUSIONS

In a large sample of residents of British Columbia (Canada), approximately one in five people had sought care for a substance use disorder or mental illness in the past 5 years. The rate of overdose was elevated in people with a mental illness alone, higher again in people with a substance use disorder alone and highest in people with a dual diagnosis. The adjusted hazard rates were similar for people with substance use disorder only and people with a dual diagnosis.

The Role of Risk or Contributory Death Factors in Methadone-Related Fatalities: A Review and Pooled Analysis

Methadone-related deaths are characterized by a wide range of post-mortem blood concentrations, due to the high pharmacokinetic/dynamic inter-individual variability, the potential subjective tolerance state and to other risk factors or comorbidities, which might enhance methadone acute toxicity. In the present study, the association among pre-existing and external conditions and diseases and the resultant methadone death capacity have been investigated. Beside a systematic literature review, a retrospective case-control study was done, dividing cases in which methadone was the only cause of death (controls), and those with associated clinical-circumstantial (naive/non-tolerant state), pathological (pulmonary or cardiovascular diseases) or toxicological (other drugs detected) conditions. Methadone concentrations were compared between the two groups and the association with conditions/diseases was assessed by multiple linear and binomial logistic regressions. Literature cases were 139, in house 35, consisting of 22 controls and 152 cases with associated conditions/diseases. Mean methadone concentrations were 2122 ng/mL and 715 ng/mL in controls and cases respectively, with a statistically significant difference (p < 0.05). Lower methadone concentrations (by 24, 19 and 33% respectively) were detected in association with naive/non-tolerant state, pulmonary diseases and presence of other drugs, and low levels of methadone (<600 ng/mL) might lead to death in the presence of the above conditions/diseases.

Past 12-month nonfatal overdose among people who inject drugs in Ukraine: City-level estimates and risk factors from a cross-sectional study

BACKGROUND

Nonfatal overdose contributes to high morbidity and is among the strongest proxies for the occurrence of overdose fatality - the leading cause of death among those who use opioids. In Ukraine, a majority of people who inject drugs (PWID) use opioids, but little is known about the relationship between drug market characteristics, nonfatal overdose (NFOD) prevalence, and risk factors for NFOD.

METHODS

We used cross-sectional respondent-driven sampling (RDS) data to explore the variability of recent (past 12 months) NFOD among PWID across Ukrainian cities and associations with individual factors. The population-averaged -cross-sectional associations were estimated and compared using generalized linear models for the binary outcome (NFOD vs. not) with robust variance estimates.

RESULTS

Recent self-reported NFOD varied between 1% and 14 % across Ukrainian cities. In adjusted analyses, overdose was associated with fewer years of injecting drugs; a higher number of types of drugs used in the past 12 months; using desomorphine, methadone, tramadol, heroin, amphetamine-type drugs or cocaine within past 12 months; using alcohol daily or weekly; recent drug treatment; and history of incarceration. Buying drugs or their ingredients through "stashes" (i.e., drugs secretly hidden in various places) and the perception of drug price increase were associated with higher odds of reporting NFOD.

CONCLUSION

The identified risk factors underscore the importance of evidence-based prevention efforts, such as scaling-up opioid agonist therapy, providing naloxone in the community and upon prison release, targeting those most likely to witness overdose and sharing overdose prevention strategies with them, and continuous monitoring of trends and contributing factors.

Heroin-induced respiratory depression and the influence of dose variation: within-subject between-session changes following dose reduction

BACKGROUND AND AIMS

Globally, more than 100 000 people die annually from opioid overdose. Opportunities to study physiological events in at-risk individuals are limited. This study examined variation of opioid dose and impact on respiratory depression in a chronic injecting heroin user at separate time-points during his long-term diamorphine maintenance treatment.

DESIGN

A single-subject study over 5 years during which participant underwent experimental studies on diamorphine-induced respiratory depression, at changing maintenance doses.

SETTING

A clinical research facility. Participant Male subject on long-term injectable diamorphine (pharmaceutical heroin) maintenance treatment for heroin addiction.

MEASUREMENTS

Physiological measures of oxygen saturation (SpO₂ ), end-tidal carbon dioxide (ETCO₂ ) and respiratory rate (RR) were used to indicate severity of respiratory depression.

FINDINGS

(1) After diamorphine injection, respiratory regulation became abnormal, with prolonged apnoea exceeding 20 sec (maximum 56 sec), elevated ETCO₂ (maximum 6.9%) and hypoxaemia (minimum SpO₂ 80%). (2) Abnormalities were greater with highest diamorphine dose: average SpO₂ was 89.3% after 100 mg diamorphine versus 93.6% and 92.8% for the two 30-mg doses. (3) However, long apnoeic pauses and high levels of ETCO₂ % were also present after lower doses.

CONCLUSIONS

With marked inter-session variability, these findings corroborate observations of inconsistent relationships between opioid dose and overdose risk.

Quantifying enhanced risk from alcohol and other factors in polysubstance-related deaths

BACKGROUND

To quantify how alcohol, polysubstance use and other factors influence opioid concentrations in drug-related deaths in West Virginia (WV), United States.

METHODS

Multiple linear regression models were employed to identify relationships among alcohol, other factors, and the concentrations of four commonly identified opioids (fentanyl, hydrocodone, oxycodone, methadone), accounting for demographic, toxicological and comorbid characteristics in WV drug-related deaths from 2005 to 2018.

RESULTS

Alcohol concentrations of 0.08% or above were associated with significant reductions in blood concentrations of fentanyl (27.5%), hydrocodone (30.5%) and methadone (32.4%). Significantly lower predicted concentrations of all opioids studied were associated with multiple opioid vs. single opioid presence, with predicted concentration reductions ranging from 13.7% for fentanyl to 65-66% for hydrocodone and oxycodone. Benzodiazepine presence was associated with small, non-statistically significant changes in opioid concentrations, while stimulant presence was associated with statistically significant reductions in hydrocodone and oxycodone concentrations.

CONCLUSIONS

Co-ingestion of alcohol, multiple opioids or stimulants were associated with significantly decreased predicted concentrations of commonly identified opioids in drug deaths. Further evidence is provided for enhanced risks from polysubstance use with opioids, which has important public health implications.

Investigating opioid-related fatalities in southern Sweden: contact with care-providing authorities and comparison of substances

Background

Opioid-related deaths have increased in Western countries over recent decades. Despite numerous studies investigating opioid-related mortality, only a few have focused on the lives of the deceased individuals prior to their deaths, specifically regarding contact with care-providing authorities such as health, social and correctional services. Furthermore, a change has been noted in the last two decades as to which opioids cause most deaths, from heroin to prescription opioids. However, studies comparing fatalities caused by different substances are rare. The aim of this study was to investigate contact with care-providing authorities during the year prior to death among individuals who died as a result of opioid intoxication and to analyse differences relating to which opioids caused their deaths.

Methods

The study is based on retrospective register data and includes 180 individuals with a history of illicit drug use, who died from opioid intoxication in Skåne, Sweden, between 1 January 2012 to 31 December 2013 and 1 July 2014 to 30 June 2016. Intoxications caused by heroin, methadone, buprenorphine and fentanyl were included. Data were collected from the National Board of Forensic Medicine, regional health care services, municipal social services and the Prison and Probation Service. Statistical testing was performed using Pearson’s chi-square test, Fisher’s exact test and the Mann-Whitney U test to analyse group differences.

Results

A total of 89% of the deceased individuals had been in contact with one or more of the care-providing authorities during the year prior to death; 75% had been in contact with health care, 69% with the social services, 28% with the Prison and Probation Service, and 23% had been enrolled in opioid substitution treatment at some point during their final year of life. Few differences appeared between the substance groups with regard to which opioid contributed to the death. In addition to opioids, sedatives were present in more than 80% of the cases. Individuals whose deaths were buprenorphine-related had been in contact with the social services to a significantly lesser extent during the year prior to death.

Conclusions

The studied population is characterised by extensive contact with care-providing authorities, thus providing numerous opportunities for authorities to reach this group with preventive and other interventions. Few differences emerged between groups with regard to which opioid had contributed to the death.

Non-fatal drug overdose after release from prison: A prospective data linkage study

BACKGROUND

Adults released from prison are at increased risk of poor health outcomes and preventable mortality, including from overdose. Non-fatal overdose (NFOD) is a strong predictor of future overdose and associated with considerable morbidity. This study aims to the determine the incidence, predictors and clinical characteristics of NFOD following release from prison.

METHODS

We used pre-release interview data collected for a randomised controlled trial in 2008-2010, and linked person-level, state-wide ambulance, emergency department, and hospital records, from a representative sample of 1307 adults incarcerated in Queensland, Australia. The incidence of NFOD following release from prison was calculated. A multivariate Andersen-Gill model was used to identify demographic, health, social, and criminal justice predictors of NFOD.

RESULTS

The crude incidence rate (IR) of NFOD was 47.6 (95%CI 41.1-55.0) per 1000 person-years and was highest in the first 14 days after release from prison (IR = 296 per 1000 person-years, 95%CI 206-426). In multivariate analyses, NFOD after release from prison was positively associated with a recent history of substance use disorder (SUD), dual diagnosis of mental illness and SUD, lifetime history of injecting drug use, lifetime history of NFOD, being dispensed benzodiazepines after release, a shorter index incarceration, and low perceived social support. The risk of NFOD was lower for people with high-risk alcohol use and while incarcerated.

CONCLUSIONS

Adults released from prison are at high risk of non-fatal overdose, particularly in the first 14 days after release. Providing coordinated transitional care between prison and the community is likely critical to reduce the risk of overdose.

Approaches to managing older people using opiates and their risk of dependence

There is little doubt that opiates have transformed healthcare, particularly in relation to pain management. However, many patients prescribed this type of drug develop problems such as dependency. Although we do not know how many older people have developed such problems due to opiate use we know that some will. It is important for nurses to understand the context in which opiates are used, as well as the specific needs of older people and how to respond to them.

Rural and urban comparisons of polysubstance use profiles and associated injection behaviors among people who inject drugs in Puerto Rico

INTRODUCTION

In contrast to urban populations, little is known about polysubstance use among rural people who inject drugs (PWID), particularly in Puerto Rico where injection drug use and related health consequences are prevalent. The aim of the study is to compare injection and non-injection substance use profiles among separate urban and rural samples of Puerto Rican PWID.

MATERIAL AND METHODS

Data for the urban sample come from 455 PWID who participated in the CDC's National HIV Behavioral Surveillance survey of injection drug use in San Juan. The data for the rural sample come from 315 PWID residing in four rural cities approximately 40-miles from San Juan. Latent class analysis was used to derive separate urban and rural profiles of weekly injection and non-injection substance use. Injection behaviors were examined as possible correlates of latent class membership.

RESULTS

Five latent classes were identified in the urban sample, and three latent classes were identified in the rural sample. Classes were similar across samples; however, key differences emerged. Both samples had classes of primary heroin injectors, primary speedball injectors, and cocaine-heroin injectors. The urban sample had one high polysubstance class. Polysubstance use profiles that shared similar characteristics between samples also shared similar injection patterns, with some variation.

DISCUSSION

Variations in substance use patterns and associated health risks are likely shaped by social and geographic boundaries.

CONCLUSIONS

Understanding variations in substance use patterns across rural and urban locales may improve surveillance efforts and tailor desistance and harm reduction efforts at the state and local levels.

Drug Overdose: Differing Risk Models for Women and Men among Opioid Users with Non-Cancer Pain

OBJECTIVE

To examine risk factors for drug overdose by sex reflecting differing patterns of opioid and other drug use.

DESIGN

National privately insured cohort.

SUBJECTS

206,869 subjects filling ≥2 opioid prescriptions from January 2009 through July 2012.

METHODS

Sex-specific prediction models for future drug overdose developed and validated using variables measured within 6 months after starting opioids: demographics, substance use, comorbidities, opioid dose, and psychoactive drugs. Logistic regression and split-sample validation were used.

RESULTS

Area under the receiver operating curves (AUCs) for both sex-specific risk models (0.80) were higher (P < 0.001) than for daily opioid dose alone. Risk factors for drug overdose were similar by sex but effects differed. For both sexes, substance use was the strongest predictor but the adjusted odds ratio (AOR) [95% CI] was 5.95 [4.33, 8.06] for women vs. 4.69 [3.24, 6.68] for men. AORs for daily opioid dose rose monotonically in men to 2.42 [1.76, 3.28] for high vs. low dose but were non-monotonic in women with 1.79 [1.35, 2.35] for high dose. AOR for 1-60 days of antidepressants vs. none was significant only in men (1.98 [1.32, 2.9]). AOR for benzodiazepine use was higher in men than women (2.75 vs 2.35, respectively). Zolpidem use was significant only in women. AUCs for sex-specific models were lower for the opposite sex and significantly lower for the men's model in the women's derivation dataset.

CONCLUSIONS

These models reveal similar risk factors by sex for drug overdose in opioid users but significant differences in effects that, if validated in other cohorts, may inform differing risk management strategies.

The Influence of Polyethylene Glycol Solution on the Dissolution Rate of Sustained Release Morphine

INTRODUCTION

Whole bowel irrigation (WBI) is a management option for overdose of medications poorly adsorbed to activated charcoal, with modified release properties, or for body packers. Polyethylene glycol (PEG) is a mixture of ethylene oxide polymers of varying molecular weight. PEG with an average molecular weight of 3350 g/mol is used for WBI. PEG electrolyte lavage solution has been shown in vitro to hasten the dissolution of acetaminophen. The impact of PEG on the pharmacokinetics of extended release pharmaceuticals is unknown. Lower average molecular weight PEG mixtures are used as solvents and excipients. We sought to investigate the impact of PEG on the release of morphine from several extended release morphine formulations.

METHODS

An in vitro gastric model was developed. To test the validity of our model, we first investigated the previously described interaction of ethanol and Avinza®. Once demonstrated, we then investigated the effect of PEG with several extended release morphine formulations.

RESULTS

In the validation portion of our study, we confirmed an ethanol Avinza® interaction. Subsequently, we did not observe accelerated release of morphine from Avinza® or generic extended release morphine in the presence of PEG.

CONCLUSION

The use of PEG for gastric decontamination following ingestion of these extended release morphine formulations is unlikely to accelerate morphine release and aggravate intoxication.

The Heroin Overdose Mystery

Heroin overdose deaths in the Unites States more than tripled from 2010 to 2014, reaching almost 11,000 per year. Despite the use of the term “overdose,” many of these victims died after self-administering an amount of opiate that would not be expected to be fatal for these drug-experienced, and drug-tolerant, individuals. Various explanations of this overdose mystery have been proposed. I describe an explanation based on Pavlovian conditioning. Organisms associate cues present at the time of drug administration with the systemic effect of the drug. These drug-predictive cues come to elicit responses that attenuate the effect of a drug. Such anticipatory conditional responses mediate chronic tolerance. If the drug is administered in the presence of novel cues, tolerance fails to occur and the victim suffers an overdose. Overdose prevention strategies should incorporate information about the contribution of drug-associated cues to drug tolerance.

A Detailed Exploration Into the Association of Prescribed Opioid Dosage and Overdose Deaths Among Patients With Chronic Pain

BACKGROUND

High opioid dosage has been associated with overdose, and clinical guidelines have cautioned against escalating dosages above 100 morphine-equivalent mg (MEM) based on the potential harm and the absence of evidence of benefit from high dosages. However, this 100 MEM threshold was chosen somewhat arbitrarily.

OBJECTIVE

To examine the association of prescribed opioid dosage as a continuous measure in relation to risk of unintentional opioid overdose to identify the range of dosages associated with risk of overdose at a detailed level.

METHODS

In this nested case-control study with risk-set sampling of controls, cases (opioid overdose decedents) and controls were identified from a population of patients of the Veterans Health Administration who were prescribed opioids and who have a chronic pain diagnosis. Unintentional fatal opioid analgesic overdose was measured from National Death Index records and prescribed opioid dosage from pharmacy records.

RESULTS

The average prescribed opioid dosage was higher (P<0.001) for cases (mean=98.1 MEM, SD=112.7; median=60, interquartile range, 30-120), than controls (mean=47.7 MEM, SD=65.2; median=25, interquartile range, 15-45). In a ROC analysis, dosage was a moderately good "predictor" of opioid overdose death, indicating that, on average, overdose cases had a prescribed opioid dosage higher than 71% of controls.

CONCLUSIONS

A clear cut-point in opioid dosage to distinguish between overdose cases and controls was not found. However, lowering the recommended dosage threshold below the 100 MEM used in many recent guidelines would affect proportionately few patients not at risk for overdose while potentially benefitting many of those at risk for overdose.

Alcohol use disorders

Alcohol use disorders are common in developed countries, where alcohol is cheap, readily available, and heavily promoted. Common, mild disorders often remit in young adulthood, but more severe disorders can become chronic and need long-term medical and psychological management. Doctors are uniquely placed to opportunistically assess and manage alcohol use disorders, but in practice diagnosis and treatment are often delayed. Brief behavioural intervention is effective in primary care for hazardous drinkers and individuals with mild disorders. Brief interventions could also encourage early entry to treatment for people with more-severe illness who are underdiagnosed and undertreated. Sustained abstinence is the optimum outcome for severe disorder. The stigma that discourages treatment seeking needs to be reduced, and pragmatic approaches adopted for patients who initially reject abstinence as a goal. To engage people in one or more psychological and pharmacological treatments of equivalent effectiveness is more important than to advocate a specific treatment. A key research priority is to improve the diagnosis and treatment of most affected people who have comorbid mental and other drug use disorders.

Emergency department presentation and mortality rate due to overdose: A retrospective cohort study on nonfatal overdoses

BACKGROUND

The aims of this retrospective cohort study are to describe the presentation characteristics for nonfatal overdose-related complaints at the emergency departments (EDs) of the metropolitan area of Bologna (northern Italy), to estimate the subsequent risk of mortality by overdose, and to identify the profiles of the subjects most at risk.

METHODS

Records of patients admitted to 10 EDs for overdose between January 2004 and December 2012 were retrospectively evaluated. The International Classification of Diseases was used to ascertain the cause of death.

RESULTS

A total of 294 episodes of overdose involving 218 individuals were identified. The total time at risk was 1048 person-years (PY). The mortality rate for all causes was 35.48 per 1000 PY for males and 20.61 per 1000 PY for females. The mortality rate for overdose was 16.6 per 1000 PY for males and 13.74 per 1000 PY for females. In the multivariate regression analysis, the time from first ED overdose access (less than 1 year risk ratio [RR]: 7.07, 95% confidence interval [CI]: 5.32-9.39) was significantly associated with death by overdose. Males, subjects aged >30 years at presentation, patients who refused ED treatment, and those having previously contacted mental health services showed an increased mortality risk due to overdose.

CONCLUSIONS

Experiencing a nonfatal overdose within the past 12 months increases the risk of mortality compared with an overdose more than 12 months earlier. Nonfatal overdose patients presenting to an ED form a specific target for prevention projects.

Distribution of naloxone for overdose prevention to chronic pain patients

In this commentary, we reflect on the growing opioid overdose epidemic and propose that chronic pain patients prescribed opioids are contributing to growing mortality rates. We advocate for expanding naloxone access and overdose prevention training, which has historically been directed when available to injection drug users, to chronic pain patients who may be at high risk for accidental opioid overdose.

Cessation of injecting drug use: The effects of health service utilisation, drug use and demographic factors

BACKGROUND

Injecting drug use is associated with a range of harms, however cessation of injecting is rare. There is a lack of evidence on factors associated with cessation, notably those related to health services other than drug treatment. We examined the incidence and identified longitudinal correlates of first episode of cessation in a cohort of people who inject drugs (PWID).

METHODS

Using discrete-time survival analysis, we examined correlates of the first episode of cessation (no self-reported injecting drug use in the past 12 months), including the use of health services, socio-demographics and drug-related behaviour in a cohort of PWID recruited between 2008 and 2010.

RESULTS

The cohort of 467 participants contributed 1527 person-years from recruitment to 2014. Under a fifth (17.8%) of people reported cessation of 12 months or more, yielding a cessation rate of 5.4 events per 100 person-years. Younger age (25-29 compared to 30 and above) (adjusted hazard ratio (AHR) 1.79, 95% confidence interval (CI) 1.07-3.00) and male gender (AHR 1.67, 95% CI 2.01-2.76) were positively associated with cessation, while past year use of benzodiazepines (AHR 0.45, 95% CI 0.28-0.72), arrest in the past year (AHR 0.50, 95% CI 0.30-0.83) and low SF-8 physical dimension score (AHR 0.42, 95% CI 0.20-1.88) were negatively associated with cessation. Outpatient service use had the largest effect on cessation (AHR 2.28, 95% CI 0.94-5.48, p=0.067).

CONCLUSIONS

Low rates of cessation emphasise the need for sustained and comprehensive harm reduction services. The relationship between outpatient services and cessation suggests that further research into the use in health services among PWID is warranted.

Can differences in the type, nature or amount of polysubstance use explain the increased risk of non-fatal overdose among psychologically distressed people who inject drugs?

BACKGROUND

This study investigates whether the type, nature or amount of polysubstance use can explain the increased risk of non-fatal overdose among people who inject drugs with severe psychological distress.

METHODS

Data came from three years (2011-2013) of the Illicit Drug Reporting System (IDRS), an annual sentinel sample of injecting drug users across Australia (n=2673). Structural Equation Modelling (SEM) was used on 14 drug types to construct five latent factors, each representing a type of polysubstance use. Tests of measurement invariance were carried out to determine if polysubstance use profiles differed between those with and without severe psychological distress. Next, we regressed non-fatal overdose on the polysubstance use factors with differences in the relationships tested between groups.

FINDINGS

Among those with severe psychological distress a polysubstance use profile characterised by heroin, oxycodone, crystal methamphetamine and cocaine use was associated with greater risk of non-fatal overdose. Among those without severe psychological distress, two polysubstance use profiles, largely characterised by opioid substitution therapies and prescription drugs, were protective against non-fatal overdose.

CONCLUSION

The types of polysubstance use profiles did not differ between people who inject drugs with and without severe psychological distress. However, the nature of use of one particular polysubstance profile placed the former group at a strongly increased risk of non-fatal overdose, while the nature of polysubstance use involving opioid substitution therapies was protective only among the latter group. The findings identify polysubstance use profiles of importance to drug-related harms among individuals with psychological problems.

Assessing risk for drug overdose in a national cohort: role for both daily and total opioid dose?

Current research on the risk of opioid analgesics with drug overdose does not account for the total morphine equivalent dose (MED) of opioids filled by a patient. In this study, time from first opioid prescription until drug overdose was examined for 206,869 privately insured patients aged 18 to 64 with noncancer pain and ≥2 filled prescriptions for Schedule II or III opioids from January 2009 to July 2012. Opioid therapy was examined in 6-month intervals including 6 months before an overdose and categorized as mean daily MED (0, 1-19, 20-49, 50-99, ≥100 mg) and total MED divided at top quartile (0, 1-1,830, >1,830 mg). Survival analysis was used, adjusting for demographics, clinical conditions, and psychoactive drugs. Relative to no opioid therapy, persons at highest risk for overdose (adjusted hazard ratios of 2-3) received a daily MED of ≥100 mg regardless of total dose or a daily MED of 50 to 99 mg with a high total MED (>1,830 mg). The hazard ratio was significantly lower (1.43, 95% confidence interval = 1.15-1.79) for 50 to 99 mg daily MED with a lower total MED (≤1,830 mg), whereas hazard ratios for lower daily MEDs did not differ by total dose. This analysis suggests that clinicians should consider total MED to assess risk of overdose for persons prescribed 50 to 99 mg daily MED.

PERSPECTIVE

When addressing risks for drug overdose, this analysis supports the need for clinicians, administrators, and policy makers to monitor not only daily opioid dose but also total dose for patients receiving 50 to 99 mg daily MED.

Medication-assisted treatment of opioid use disorder: review of the evidence and future directions

Medication-assisted treatment of opioid use disorder with physiological dependence at least doubles rates of opioid-abstinence outcomes in randomized, controlled trials comparing psychosocial treatment of opioid use disorder with medication versus with placebo or no medication. This article reviews the current evidence for medication-assisted treatment of opioid use disorder and also presents clinical practice imperatives for preventing opioid overdose and the transmission of infectious disease. The evidence strongly supports the use of agonist therapies to reduce opioid use and to retain patients in treatment, with methadone maintenance remaining the gold standard of care. Combined buprenorphine/naloxone, however, also demonstrates significant efficacy and favorable safety and tolerability in multiple populations, including youth and prescription opioid-dependent individuals, as does buprenorphine monotherapy in pregnant women. The evidence for antagonist therapies is weak. Oral naltrexone demonstrates poor adherence and increased mortality rates, although the early evidence looks more favorable for extended-release naltrexone, which has the advantages that it is not subject to misuse or diversion and that it does not present a risk of overdose on its own. Two perspectives-individualized treatment and population management-are presented for selecting among the three available Food and Drug Administration-approved maintenance therapies for opioid use disorder. The currently unmet challenges in treating opioid use disorder are discussed, as are the directions for future research.

Mortality related to novel psychoactive substances in Scotland, 2012: an exploratory study

BACKGROUND

The growth of novel psychoactive substances (NPS) over the last decade, both in terms of availability and consumption, is of increasing public health concern. Despite recent increases in related mortality, the circumstances surrounding and characteristics of individuals involved in NPS deaths at a population level remain relatively unknown.

METHODS

The Scottish National Drug Related Death Database (NDRDD) collects a wide-range of data relating to the nature and circumstances of individuals who have died a drug-related death (DRD). We conducted exploratory descriptive analysis of DRDs involving NPS recorded by the NDRDD in 2012. Statistical testing of differences between sub-groups was also conducted where appropriate.

RESULTS

In 2012, we found 36 DRDs in Scotland to have NPS recorded within post-mortem toxicology. However, in only 23 of these cases were NPS deemed by the reporting pathologist to be implicated in the actual cause of death. The majority of NPS-implicated DRDs involved Benzodiazepine-type drugs (13), mainly Phenazepam (12). The remaining 10 NPS-implicated deaths featured a range of different Stimulant-type drugs. The majority of these NPS-implicated deaths involved males and consumption of more than one drug was recorded by toxicology in all except one case. NPS-implicated deaths involving Benzodiazepine-type NPS drugs appeared to involve older individuals known to be using drugs for a considerable period of time, many of whom had been in prison at some point in their lives. They also typically involved combinations of opioids and benzodiazepines; no stimulant drugs were co-implicated. Deaths where stimulant-type NPS drugs were implicated appeared to be a younger group in comparison, all consuming two or more Stimulant-type drugs in combination.

CONCLUSION

This exploratory study provides an important insight into the circumstances surrounding and characteristics of individuals involved in NPS deaths at a population level. It identifies important issues for policy and practice, not least the prominent role of unlicensed benzodiazepines in drug-related mortality, but also the need for a range of harm reduction strategies to prevent future deaths.

Patterns and correlates of non-fatal heroin overdose at 11-year follow-up: findings from the Australian Treatment Outcome Study

BACKGROUND

Overdose is a major cause of morbidity and mortality amongst opioid users. This paper reported recent non-fatal overdose amongst the Australian Treatment Outcome Study (ATOS) cohort at 11-year follow-up, and characteristics that predict recent overdose.

METHODS

Longitudinal cohort, with 431 (70.1%) of the original 615 participants interviewed. Participants were administered the ATOS structured interview, addressing demographics, treatment history, drug use, heroin overdose, criminality, health and psychopathology.

FINDINGS

Mean time since heroin initiation was 20.4 years. By 11-year follow-up, the proportion who had overdosed was 67.5%, and 24.4% had experienced five or more overdoses. In the 12 months preceding 11-year follow-up, 4.9% had overdosed (11.8% of those who had used heroin in that period). Of the 21 participants who had recently overdosed, 20 (95.2%) had overdosed previously, and 19 (90.5%) were not enrolled in a treatment programme at the time. Those who had recently overdosed reported higher levels of use of opiates other than heroin (57.1% vs 24.9%), benzodiazepines (61.9% vs 30.5%,), methamphetamine (38.1% vs 16.8%) and cocaine (19.0% vs 3.7%). They also had exhibited higher levels of heroin use and other drug use at baseline, 12 and 24 month follow-ups.

CONCLUSIONS

While the prevalence had declined, overdoses still occurred. A history of overdose and polydrug use patterns continued to provide strong markers for those at continued risk.