Which drugs cause overdose among opiate misusers? Study of personal and witnessed overdoses

A qualitative study of benzodiazepine/z-drug and opioid co-use patterns and overdose risk

BACKGROUND

Co-use of benzodiazepines and/or 'z-drugs' along with opioids is linked to the rise in drug related deaths (DRD) in the UK. Understanding patterns of co-use could inform harm reduction strategies for reducing DRDs. This study explored how people co-use, including dosages, timings, methods of administration, use of other substances and desired effects sought.

METHODS

Forty-eight semi-structured interviews across Glasgow in Scotland (n = 28), Bristol (n = 10) and Teesside (n = 10) in England with individuals who co-use illicit and/or prescribed opioids and benzodiazepines/z-drugs were conducted. Eighteen interviews were co-facilitated with qualitatively trained local peer researchers. Interviews were analysed using the Framework method.

RESULTS

Six co-use patterns were generated: (1) co-use to aid sleep or come down, (2) curated co-use, opioid agonist therapy (OAT) only (3) morning and evening benzodiazepine doses with opioids throughout the day (4) co-use binges (5) co-use throughout the day, (6) benzodiazepine use throughout the day plus OAT. Patterns one to three reflected more controlled co-use with a focus on self-medicating to give confidence, manage anxiety, promote sleep and come-down from cocaine/ketamine. Patterns four to six involved greater poly-drug use, and less controlled co-use with a focus on seeking euphoria ("warm glow", "gouching out") or oblivion (to escape untreated mental health conditions and trauma). Patterns two, three, five and six involved daily co-use. People switched between patterns depending on available resources (e.g. finances) or changes to prescriptions (opioids or benzodiazepines). Near-fatal overdoses were reported by participants across all co-use patterns. Patterns four to six were conceptualised as presenting greater overdose risk due to less controlled co-use and more extensive polydrug use.

CONCLUSIONS

The patterns identified provide opportunities for future harm reduction strategies, tailoring advice to patterns of use, updated prescribing guidance and policies, and the need for better access to mental health care, for people who co-use benzodiazepines and opioids to reduce DRDs.

The epidemiology of benzodiazepine misuse: A systematic review

BACKGROUND

Benzodiazepine misuse is a growing public health problem, with increases in benzodiazepine-related overdose deaths and emergency room visits in recent years. However, relatively little attention has been paid to this emergent problem. We systematically reviewed epidemiological studies on benzodiazepine misuse to identify key findings, limitations, and future directions for research.

METHODS

PubMed and PsychINFO databases were searched through February 2019 for peer-reviewed publications on benzodiazepine misuse (e.g., use without a prescription; at a higher frequency or dose than prescribed). Eligibility criteria included human studies that focused on the prevalence, trends, correlates, motives, patterns, sources, and consequences of benzodiazepine misuse.

RESULTS

The search identified 1970 publications, and 351 articles were eligible for data extraction and inclusion. In 2017, benzodiazepines and other tranquilizers were the third most commonly misused illicit or prescription drug in the U.S. (approximately 2.2% of the population). Worldwide rates of misuse appear to be similar to those reported in the U.S. Factors associated with misuse include other substance use, receipt of a benzodiazepine prescription, and psychiatric symptoms and disorders. Benzodiazepine misuse encompasses heterogeneous presentations of motives, patterns, and sources. Moreover, misuse is associated with myriad poor outcomes, including mortality, HIV/HCV risk behaviors, poor self-reported quality of life, criminality, and continued substance use during treatment.

CONCLUSIONS

Benzodiazepine misuse is a worldwide public health concern that is associated with a number of concerning consequences. Findings from the present review have implications for identifying subgroups who could benefit from prevention and treatment efforts, critical points for intervention, and treatment targets.

Polydrug use and its association with drug treatment outcomes among primary heroin, methamphetamine, and cocaine users

BACKGROUND

Polydrug use may challenge effective treatment for substance use disorders. We evaluate whether secondary substance use modifies the association between treatment and primary drug use among primary heroin, cocaine and methamphetamine (MA) users.

METHODS

Data were obtained from prospective cohort studies on people who use illicit drugs (PWUD) in California, USA. Using repeated monthly data on self-reported secondary substance use (heroin, cocaine, MA, alcohol or marijuana; ≥1day in a month), primary drug use (≥1day in a month), and treatment participation, collected via timeline follow-back, we fitted generalized linear mixed multiple regression models controlling for potential confounders to examine the interactions between treatment and secondary substance use on the odds of primary heroin, cocaine and MA use, respectively.

RESULTS

Included in our study were 587 primary heroin, 444 primary MA, and 501 primary cocaine users, with a median of 32.4, 13.3 and 18.9 years of follow-up, respectively. In the absence of secondary substance use, treatment was strongly associated with decreased odds of primary drug use (adjusted odds ratios (aORs): 0.25, 95% CI: 0.24, 0.27, 0.07 (0.06, 0.08), and 0.07 (0.07, 0.09)) for primary heroin, MA, and cocaine users, respectively. Secondary substance use of any kind moderated these associations (0.82 (0.78, 0.87), 0.25 (0.21, 0.30) and 0.53 (0.45, 0.61), respectively), and these findings were consistent for each type of secondary substance considered. Moreover, we observed different associations in terms of direction and magnitude between secondary substance use and primary drug use during off-treatment periods across substance types.

CONCLUSION

This study demonstrates secondary substance use moderates the temporal associations between treatment and primary drug use among primary heroin, MA and cocaine users. Disparate patterns of polydrug use require careful measurement and analysis to inform targeted treatment for polydrug users.

From Salt Injection to Naloxone: Accuracy and Myths in Peer Resuscitation Methods for Opiate Overdose

One hundred and eight opiate addicts attending an in-patient opiate treatment unit were interviewed, using a mixed quantitative–qualitative approach, to investigate their experiences of witnessing overdoses, the associated interpretations and perceived cause of the overdose. Poly drug use and frequency of witnessed overdose was high among the sample. Use of 14 different combinations of drugs were reported, 8 of which involved the use of alcohol, and 7 benzodiazepines. Perceived cause of overdose involved attributions relating to the use of alcohol, in particular strong lager, small quantities of heroin and low levels of current opiate tolerance. Peer initiated resuscitation techniques revealed a range of responses from the probably valuable (recovery position, summon ambulance, administer naloxone) to the ineffective or frankly harmful (injecting with salt solution, immersing in a cold bath). The findings highlight the need for an overdose prevention program during in-patient detoxification and rehabilitation.

Self-perceived problem with alcohol use among opioid substitution treatment clients

BACKGROUND AND AIM

Excessive alcohol use increases mortality and morbidity among opioid substitution therapy (OST) clients. Regular attendance for OST dosing presents key opportunities for screening and treatment. However, individuals' perception of their alcohol consumption as problematic or otherwise may impact their willingness to change. This study examines patterns of alcohol consumption among OST clients, perceptions of their own use and correlates of excess consumption.

METHODS

Confidential, structured interviews were conducted with 264 clients of two Sydney OST clinics. Alcohol consumption was assessed using the Alcohol Use Disorders Identification Test (AUDIT); and illicit drug dependence with the Severity of Dependence Scale.

RESULTS

Forty-one percent of the participants scored ≥8 on the AUDIT ('AUDIT-positive'), indicating excessive alcohol use. The higher a participant's AUDIT score, the more likely they were to demonstrate insight into the potential problems associated with their drinking (linear trend, p<0.01). However, only half of AUDIT-positive participants believed they drank too much and/or had a problem with alcohol. One-third had discussed their drinking with OST staff, and a similar proportion reported a history of alcohol treatment. AUDIT-positive participants were more likely than others to be classified as dependent on an illicit drug in the last six months (AOR=1.76, 95% CI:1.00-3.09), report a history of alcohol treatment (AOR=5.70, 95% CI:2.83-11.48) and believe it is safe to drink 4+ standard drinks in one session (AOR=5.30, 95% CI:2.79-10.06).

CONCLUSIONS

OST clients with AUDIT scores ≥8 appear to underestimate the risks associated with their alcohol consumption. Regular assessments of alcohol use and targeted brief alcohol interventions may improve health outcomes among OST clients.

Non-fatal heroin overdose, treatment exposure and client characteristics: Findings from the Australian Treatment Outcome Study (ATOS)

The relationship between treatment exposure, drug use, psychosocial variables and non-fatal heroin overdose was examined among a cohort of 495 heroin users, re-interviewed at 12 months. The 12-month overdose rate declined from 24% to 12%, and the proportion administered naloxone declined from 15% to 7%. There were significant reductions in overdose among those who entered maintenance therapies (22% to 4%) and residential rehabilitation (33% vs. 19%) at baseline, but not among those who entered detoxification or were not entering treatment. The total number of treatment days received over the follow-up period was associated independently with a reduced risk of overdose. Each extra treatment day was associated with a 1% reduction in risk of overdose over the follow-up period. By contrast, more treatment episodes were associated with an increased risk of overdose (OR 1.62). Other independent predictors of overdose over follow-up were more extensive polydrug use (OR 1.40), and having overdosed in the year preceding the study (OR 7.87).

A systematic review of research examining benzodiazepine-related mortality

PURPOSE

This paper will review literature examining the association of benzodiazepine use and mortality.

METHODS

An extensive literature review was undertaken to locate all English-language published articles that examine mortality risk associated with use of benzodiazepines from 1990 onwards.

RESULTS

Six cohort studies meeting the criteria above were identified. The results were mixed. Three of the studies assessed elderly populations and did not find an increased risk of death associated with benzodiazepine use, whereas another study of the general population did find an increased risk, particularly for older age groups. A study of a middle aged population found that regular benzodiazepine use was associated with an increased mortality risk, and a study of 'drug misusers' found a significant relationship between regular use of non-prescribed benzodiazepines and fatal overdose. Three retrospective population-based registry studies were also identified. The first unveiled a high relative risk (RR) of death due to benzodiazepine poisoning versus other outcomes in patients 60 or older when compared to those under 60. A positive but non-significant association between benzodiazepine use and driver-responsible fatalities in on-road motor vehicle accidents was reported. Drug poisoning deaths in England showed benzodiazepines caused 3.8% of all deaths caused by poisoning from a single drug.

CONCLUSION

On the basis of existing research there is limited data examining independent effects of illicit benzodiazepine use upon mortality. Future research is needed to carefully examine risks of use in accordance with doctors' prescriptions and extra-medical use.

Mono- versus polydrug abuse patterns among publicly funded clients

To examine patterns of mono- versus polydrug abuse, data were obtained from intake records of 69,891 admissions to publicly funded treatment programs in Tennessee between 1998 and 2004. While descriptive statistics were employed to report frequency and patterns of mono- and polydrug abuse by demographic variables and by study years, bivariate logistic regression was applied to assess the probability of being a mono- or polydrug abuser for a number of demographic variables. The researchers found that during the study period 51.3% of admissions reported monodrug abuse and 48.7% reported polydrug abuse. Alcohol, cocaine, and marijuana were the most commonly abused substances, both alone and in combination. Odds ratio favored polydrug abuse for all but one drug category-other drugs. Gender did not affect drug abuse patterns; however, admissions for African Americans and those living in urban areas exhibited higher probabilities of polydrug abuse. Age group also appeared to affect drug abuse patterns, with higher odds of monodrug abuse among minors and adults over 45 years old. The discernable prevalence of polydrug abuse suggests a need for developing effective prevention strategies and treatment plans specific to polydrug abuse.

Cocaine- and opiate-related fatal overdose in New York City, 1990-2000

Background

In New York City (NYC), the annual mortality rate is higher for accidental drug overdoses than for homicides; cocaine and opiates are the drugs most frequently associated with drug overdose deaths. We assessed trends and correlates of cocaine- and opiate-related overdose deaths in NYC during 1990–2000.

Methods

Data were collected from the NYC Office of the Chief Medical Examiner (OCME) on all fatal drug overdoses involving cocaine and/or opiates that occurred between 1990–2000 (n = 8,774) and classified into three mutually exclusive groups (cocaine only; opiates-only; cocaine and opiates). Risk factors for accidental overdose were examined in the three groups and compared using multinomial logistic regression.

Results

Overall, among decedents ages 15–64, 2,392 (27.3%) were attributed to cocaine only and 2,825 (32.2%) were attributed to opiates-only. During the interval studied, the percentage of drug overdose deaths attributed to cocaine only fell from 29.2% to 23.6% while the percentage of overdose deaths attributed to opiates-only rose from 30.6% to 40.1%. Compared to New Yorkers who fatally overdosed from opiates-only, fatal overdose attributed to cocaine-only was associated with being male (OR = 0.71, 95% CI 0.62–0.82), Black (OR = 4.73, 95% CI 4.08–5.49) or Hispanic (OR = 1.51, 95% CI 1.29–1.76), an overdose outside of a residence or building (OR = 1.34, 95% CI 1.06–1.68), having alcohol detected at autopsy (OR = 0.50, 95% CI 0.44–0.56) and older age (55–64) (OR = 2.53 95% CI 1.70–3.75)).

Conclusion

As interventions to prevent fatal overdose become more targeted and drug specific, understanding the different populations at risk for different drug-related overdoses will become more critical.

The association between change in social network characteristics and non-fatal overdose: results from the SHIELD study in Baltimore, MD, USA

BACKGROUND

Social network factors have been reported to be associated with non-fatal overdose. Yet, few studies have examined how changes in social network characteristics may influence overdose risk. The purpose of this study was to examine the relationship between changes in social network and non-fatal overdose.

METHODS

Data for this study came from 659 participants enrolled in the Self-Help in Eliminating Life-Threatening Diseases (SHIELD) study, who reported details about their non-fatal overdose experience between enrollment and a follow-up visit. Social network characteristics were described at both time points and net change in network composition was calculated.

RESULTS

The sample was predominately male (56%), African-American (96%) and unemployed (78%). Experience of non-fatal overdose between time points was reported by 15%. Older age was associated with non-fatal overdose. Interaction between incarceration status and drug use was statistically significant. Protective factors were having a denser network at baseline and a network that became denser after adjusting for gender, homelessness, incarceration, drug use and total network size.

CONCLUSIONS

Drug users' social networks are an important target for overdose prevention interventions. Further research on overdose risk and movement of specific network members in and out of networks is warranted.

Alcohol use outcomes and heavy drinking at 4-5 years among a treatment sample of drug misusers

This paper investigates alcohol outcomes and heavy drinking among 418 drug misusers from the National Treatment Outcome Research Study who completed followup interviews at 1, 2, and 4-5 years. About a quarter of the sample were drinking heavily at intake. Alcohol consumption at followup was predicted by drinking prior to intake, and about a quarter of those who were classified as alcohol abstainers, medium-level drinkers, or heavy drinkers at intake, remained in the same drinking category at all assessment points. Drinking outcomes were not related to opioid use. Heavy drinkers at followup were more likely to be using non-opioid drugs. The poor drinking outcomes are a matter for concern. Drug misusers with concurrent alcohol problems may require special treatment provision. The extent of heavy drinking among drug misusers both before and after treatment indicates a need to develop and strengthen programs and interventions to tackle alcohol-related problems in this patient group.

Opiates, cocaine and alcohol combinations in accidental drug overdose deaths in New York City, 1990-98

AIMS

Accidental drug overdose contributes substantially to mortality among drug users. Multi-drug use has been documented as a key risk factor in overdose and overdose mortality in several studies. This study investigated the contribution of multiple drug combinations to overdose mortality trends.

DESIGN

We collected data on all overdose deaths in New York City between 1990 and 1998 using records from the Office of the Chief Medical Examiner (OCME). We standardized yearly overdose death rates by age, sex and race to the 1990 census population for NYC to enable comparability between years relevant to this analysis.

FINDINGS

Opiates, cocaine and alcohol were the three drugs most commonly attributed as the cause of accidental overdose death by the OCME, accounting for 97.6% of all deaths; 57.8% of those deaths were attributed to two or more of these three drugs in combination. Accidental overdose deaths increased in 1990-93 and subsequently declined slightly in 1993-98. Changes in the rate of multi-drug combination deaths accounted for most of the change in overdose death rates, whereas single drug overdose death rates remained relatively stable. Trends in accidental overdose death rates within gender and racial/ethnic strata varied by drug combination suggesting different patterns of multi-drug use among different subpopulations.

CONCLUSIONS

These data suggest that interventions to prevent accidental overdose mortality should address the use of drugs such as heroin, cocaine and alcohol in combination.

Methadone-related deaths in Western Australia 1993-99

OBJECTIVES

To describe methadone-related deaths in Western Australia from 1993 to 1999 and determine differences between deaths in methadone maintenance treatment (MMT) in the public and private sectors.

METHOD

Review of coronial and clinical data for all cases identified by methadone detected from toxicological analysis of post-mortem samples between January 1993 and December 1999.

RESULTS

Eighty-four methadone-related deaths were identified. The majority (64%) were accidental; 74% of these were caused by a combination of drug effects. Overall, benzodiazepines were present in 74% of all decedents. Thirty-six (43% of all decedents) were registered in MMT when they died. Twenty-two decedents were registered with Next Step, of whom two died in the first week of treatment. In contrast, 14 decedents were registered with the CBMP, of whom eight died in the first week of treatment. The mortality rate in MMT peaked in 1998 (7.7 per 1,000 clients treated), one year after expansion into the private sector. A range of co-existing health conditions were present among decedents including: blood-bome viruses (BBVs), chronic pain/injury, asthma, epilepsy, diabetes, obesity, kidney disease, cardiac disease, pancreatitis, gall stones, paraplegia, cerebral palsy, schizophrenia, depression, suicidal ideation and arthritis.

CONCLUSIONS

Overall, methadone-related mortality did not increase significantly despite an increase in the population in MMT. Polydrug use, in particular the use of benzodiazepines in combination with methadone, was a major risk factor for premature mortality.

IMPLICATIONS

More attention is needed to reduce the use of benzodiazepines in combination with methadone. Decentralisation of methadone services into general practice must be carefully monitored to minimise the risk of mortality.

Reduced injection risk and sexual risk behaviours after drug misuse treatment: results from the National Treatment Outcome Research Study

This paper investigates injecting, shared use of needles/syringes and sexual risk behaviours at intake to treatment and at one-year follow-up among 753 drug users recruited to the National Treatment Outcome Research Study (NTORS). Injecting, sharing and having unprotected sex were substantially reduced among clients admitted to methadone programmes and among those admitted to residential treatments. The overall levels of risk fell after treatment, and the majority of those who were engaged in high risk behaviours at intake had stopped at follow-up. The results also show the variability of individual outcomes. A minority persisted with their risk behaviour, and others who were not at risk at intake who had started to engage in risky behaviours at follow-up. The behaviour of these clients creates a focal point for risk as well as being a threat to public health. Several social and psychological factors were predictive of health risk behaviours. These included frequency and duration of heroin use, polydrug use, alcohol use, gender, ethnicity, having a drug-using partner, anxiety and depression. The results indicate the important role that can be played by treatment services in helping to reduce the risk of blood-borne infections. We suggest that risk reduction interventions are an important and effective component of treatment programmes.

Reductions in non-fatal overdose after drug misuse treatment: results from the National Treatment Outcome Research Study (NTORS)

Few studies have reported changes in rates of overdose after drug misuse treatment. This paper investigates changes in non-fatal overdose between treatment intake and 1 year follow-up among a sample of 753 clients recruited to the National Treatment Outcome Research Study (NTORS). A relatively high rate of overdose (15%) was reported during the 3 months prior to treatment. Variables predictive of overdose at intake to treatment included injecting, frequency of benzodiazepine and cocaine use, quantity of alcohol consumption, and levels of anxiety. At 1 year follow-up, the rate of non-fatal overdose had fallen to 6%. Reduced rates of non-fatal overdose were found for clients treated in both residential and community treatment settings. Reductions in overdose were linked to improvements in frequency of drug use and lower rates of injecting. Clients who overdosed at follow-up showed no improvements in their substance use, except for frequency of crack cocaine use. The risk of non-fatal overdose at 1 year was associated with injecting and multiple drug use. These findings support the view that treatment an important role can play in reducing deaths among drug misusers.

A prospective study of mortality among drug misusers during a 4-year period after seeking treatment

AIMS

The opportunity to study deaths as they occur within the framework of a prospective cohort study is relatively uncommon. This study investigates deaths among drug misusers over a 4-year period, with specific attention to the circumstances and causes of death, and risk factors for mortality. The study also critically examines the recording of drug-related deaths.

DESIGN, SETTING, PARTICIPANTS

Prospective cohort study of 1075 drug misusers recruited to 54 treatment programmes during 1995.

MEASUREMENTS

Data derived from interviews conducted with clients at intake, death certificates and post-mortem examinations.

FINDINGS

The annual mortality rate was 1.2%, about six times higher than that for a general, age-matched population. Fourteen per cent of the deaths were due to self-inflicted injuries, accidents or violence and 18%, were due to medical causes. The majority of deaths (68%) were associated with drug overdoses. Opiates were the drugs most commonly detected during post-mortem examinations. In the majority of cases, more than one drug was detected. Polydrug use and, specifically, heavy drinking, and use of benzodiazepines and amphetamines, were identified as risk factors for mortality. Anxiety and homelessness were also predictive of increased mortality.

CONCLUSIONS

We suggest that drug misusers and those working with drug misusers need to be more alert to the risks of polydrug use, including the combined use of alcohol with illicit drugs. The study revealed inconsistencies in the recording of drug-related deaths on death certificates. The routine recording of all substances detected during toxicological examination would improve the accuracy of death certification.

Excessive alcohol consumption and drinking expectations among clients in methadone maintenance

Excessive alcohol consumption and related problems are common among clients in methadone maintenance treatment (MMT), yet relatively little is known about the psychological and social determinants of alcohol-related attitudes and behaviors during treatment. This study reports on the prevalence of alcohol dependence, patterns of alcohol consumption and preliminary findings about clients' beliefs that they will change their drinking behavior in the future. Data were gathered from personal interviews with 66 clients attending a MMT program in South London (some 80.5% of the eligible caseload). Forty-one percent of the overall sample met DSM-IV criteria for alcohol dependence in the past 12 months. Among clients who reported drinking in the past month (n = 50), 54% were classified as dependent, and these clients reported consuming an average of 23.5 UK standard units of absolute alcohol (188g/6.58 ounces) on a typical drinking day in the past month. Exploratory analyses suggested that expectations to change drinking behavior were predicted by subjective norms (social pressures), perceived functions of alcohol use, past drinking levels and current dose of methadone. Clinicians engaged in alcohol problems assessment and counseling during MMT could usefully examine these influences to strengthen treatment provision.

Peer-initiated overdose resuscitation: fellow drug users could be mobilised to implement resuscitation

Research interviews about overdose experiences were conducted with 115 patients attending a methadone maintenance clinic in south London, UK. While almost half (49.6%) reported having experienced overdose personally (on an average of four occasions each), almost all (97.4%) reported that they had witnessed overdoses (on an average of six occasions each). This represents a total of 706 overdoses witnessed, of which 106 had resulted in fatalities. The vast majority of patients (86/97) reported that they had taken actions when they had witnessed overdoses with those acting taking an average of nearly threee different actions on the last occasion on which they had seen someone overdosing. Most respondents reported that they would be willing to act, even if they did not know the overdose victim personally and that they had not been deterred from acting by the previous response from the emergency services. Fear of punishment was not a strong deterrent from acting certainly not for this sample, with many participants also expressing an interest in expanding their repertoire of overdose interventions, for example through training in resuscitation techniques and by keeping naloxone at home for use in overdose emergency.