Deaths in methadone maintenance treatment in New South Wales, Australia 1990-1995

Impact of prerelease methadone on mortality among people with HIV and opioid use disorder after prison release: results from a randomized and participant choice open-label trial in Malaysia

INTRODUCTION

Mortality is elevated after prison release and may be higher in people with HIV and opioid use disorder (OUD). Maintenance with opioid agonist therapy (OAT) like methadone or buprenorphine reduces mortality in people with OUD and may confer benefits to people with OUD and HIV leaving prison. Survival benefits of OAT, however, have not been evaluated prospectively in people with OUD and HIV leaving prison.

METHODS

This study prospectively evaluated mortality after prison release and whether methadone initiated before release increased survival after release in a sample of men with HIV and OUD (n = 291). We linked national death records to data from a controlled trial of prerelease methadone initiation conducted from 2010 to 2014 with men with HIV and OUD imprisoned in Malaysia. Vital statistics were collected through 2015. Allocation to prerelease methadone was by randomization (n = 64) and participant choice (n = 246). Cox proportional hazards models were used to estimate treatment effects of prerelease methadone on postrelease survival.

RESULTS

Overall, 62 deaths occurred over 872.5 person-years (PY) of postrelease follow-up, a crude mortality rate of 71.1 deaths per 1000 PY (95% confidence interval [CI] 54.5-89.4). Most deaths were of infectious etiology, mostly related to HIV. In a modified intention-to-treat analysis, the impact of prerelease methadone on postrelease mortality was consistent with a null effect in unadjusted (hazard ratio [HR] 1.3, 95% CI 0.6-3.1) and covariate-adjusted (HR 1.2, 95% CI 0.5-2.8) models. Predictors of mortality were educational level (HR 1.4, 95% CI 1.0-1.8), pre-incarceration alcohol use (HR 2.0, 95% CI 1.1-3.9), and lower CD4⁺ T-lymphocyte count (HR 0.8 per 100-cell/mL increase, 95% CI 0.7-1.0).

CONCLUSIONS

Postrelease mortality in this sample of men with HIV and OUD was extraordinarily high, and most deaths were likely of infectious etiology. No effect of prerelease methadone on postrelease mortality was observed, which may be due to study limitations or an epidemiological context in which inadequately treated HIV, and not inadequately treated OUD, is the main cause of death after prison release.

TRIAL REGISTRATION

NCT02396979. Retrospectively registered 24/03/2015.

Effect of TRV130 and methadone on fentanyl-vs.-food choice and somatic withdrawal signs in opioid-dependent and post-opioid-dependent rats

The high efficacy mu-opioid receptor (MOR) agonist methadone is an effective opioid use disorder (OUD) medication used exclusively in opioid-dependent patients. However, methadone has undesirable effects that limit its clinical efficacy. Intermediate efficacy MOR agonists may treat OUD with fewer undesirable effects. We compared the effects of methadone with the intermediate efficacy MOR agonist TRV130 (oliceridine) on fentanyl-vs.-food choice and somatic withdrawal signs in opioid-dependent and post-opioid-dependent rats. Male rats (n = 20) were trained under a fentanyl-vs.-food choice procedure. Rats were then provided extended fentanyl (3.2 µg/kg/infusion) access (6 p.m.-6 a.m.) for 10 days to produce opioid dependence/withdrawal. Rats were treated with vehicle (n = 7), TRV130 (3.2 mg/kg; n = 8), or methadone (3.2 mg/kg; n = 5) three times per day after each extended-access session (8:30 a.m., 11 a.m., 1:30 p.m.). Withdrawal sign scoring (1:55 p.m.) and choice tests (2-4 p.m.) were conducted daily. Vehicle, TRV130, and methadone effects on fentanyl choice were redetermined in post-opioid-dependent rats. Vehicle-, TRV130-, and methadone-treated rats had similar fentanyl intakes during extended access. Vehicle-treated rats exhibited increased withdrawal signs and decreased bodyweights. Both methadone and TRV130 decreased these withdrawal signs. TRV130 was less effective than methadone to decrease fentanyl choice and increase food choice in opioid-dependent rats. Neither methadone nor TRV130 decreased fentanyl choice in post-opioid-dependent rats. Results suggest that higher MOR activation is required to reduce fentanyl choice than withdrawal signs in fentanyl-dependent rats. Additionally, given that TRV130 did not precipitate withdrawal in opioid-dependent rats, intermediate efficacy MOR agonists like TRV130 may facilitate the transition of patients with OUD from methadone to lower efficacy treatments like buprenorphine.

The Inclusion of Patients’ Reported Outcomes to Inform Treatment Effectiveness Measures in Opioid Use Disorder. A Systematic Review

Introduction

Objective

Methods

Results

Conclusion

Systematic Review Registration

Is extended release naltrexone superior to buprenorphine-naloxone to reduce drinking among outpatients receiving treatment for opioid use disorder? A secondary analysis of the CTN X:BOT trial

BACKGROUND

The comparative effectiveness of extended-release naltrexone versus buprenorphine-naloxone for opioid relapse prevention (X:BOT) trial showed that following induction, treatment with the sublingual agonist (buprenorphine-naloxone, BUP-NX) or injected antagonist (extended release naltrexone, XR-NTX) produced similar reductions in opioid relapse in injection users with opioid use disorder (OUD). Because XR-NTX reduces drinking in alcohol use disorder (AUD), we conducted a secondary analysis of the X:BOT sample of patients successfully inducted onto treatment to determine whether XR-NTX (n = 204) was superior to BUP-NX (n = 270) in reducing drinking or heavy drinking in patients with OUD.

METHODS

Standard drink units consumed were measured using the Timeline Follow-back method. Mixed-models regression was used to examine the monthly frequency of any drinking and heavy drinking over 6 months of treatment. We used a proportional hazard survival analysis to examine the time to first drink.

RESULTS

Both treatment groups reduced drinking from baseline to posttreatment (small to medium effect), but no differences between groups were detected. However, only 29% (n = 136) of the sample had AUD and 19% (n = 26/136) of those were abstinent before treatment. Analysis of a subsample enriched for possible drinking included 136 individuals with an AUD diagnosis plus 43 who did not have AUD, but reported at least one day of heavy drinking prior to the study. However, this subsample reported only 32% of days of any drinking with a median of only 13% of days designated as "heavy." Within this subsample, at baseline, the BUP-NX group reported more mean drinks per drinking day than the XR-NTX group (p = 0.03); however, there were no other significant group differences on drinking observed before, during, or at the end of treatment.

CONCLUSIONS

There was an overall reduction in drinking during treatment of OUD using both agonist and antagonist medications, so that the hypothesis that XR-NTX would be superior to BUP-NX was not supported. The study is limited by low levels of comorbid AUD or heavy drinking observed in X:BOT trial participants seeking treatment for OUD.

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.

Are patients' goals in treatment associated with expected treatment outcomes? Findings from a mixed-methods study on outpatient pharmacological treatment for opioid use disorder

OBJECTIVES

Existing methods of measuring effectiveness of pharmacological treatment for opioid use disorder (OUD) are highly variable. Therefore, understanding patients' treatment goals is an integral part of patient-centred care. Our objective is to explore whether patients' treatment goals align with a frequently used clinical outcome, opioid abstinence.

DESIGN

Triangulation mixed-methods design.

SETTING AND PARTICIPANTS

We collected prospective data from 2030 participants who were receiving methadone or buprenorphine-naloxone treatment for a diagnosis of OUD in order to meet study inclusion criteria. Participants were recruited from 45 centrally-managed outpatient opioid agonist therapy clinics in Ontario, Canada. At study entry, we asked, 'What are your goals in treatment?' and used NVivo software to identify common themes.

PRIMARY OUTCOME MEASURE

Urine drug screens (UDS) were collected for 3 months post-study enrolment in order to identify abstinence versus ongoing opioid use (mean number of UDS over 3 months=12.6, SD=5.3). We used logistic regression to examine the association between treatment goals and opioid abstinence.

RESULTS

Participants had a mean age of 39.2 years (SD=10.7), 44% were women and median duration in treatment was 2.6 years (IQR 5.2). Six overarching goals were identified from patient responses, including 'stop or taper off of treatment' (68%), 'stay or get clean' (37%) and 'live a normal life' (14%). Participants reporting the goal 'stay or get clean' had lower odds of abstinence at 3 months than those who did not report this goal (OR=0.73, 95% CI 0.59 to 0.91, p=0.005). Although the majority of patients wanted to taper off or stop medication, this goal was not associated with opioid abstinence, nor were any of their other goals.

CONCLUSIONS

Patient goals in OUD treatment do not appear to be associated with programme measures of outcome (ie, abstinence from opioids). Future studies are needed to examine outcomes related to patient-reported treatment goals found in our study; pain management, employment, and stopping/tapering treatment should all be explored.

Treatment Outcomes in Patients With Opioid Use Disorder Who Were First Introduced to Opioids by Prescription: A Systematic Review and Meta-Analysis

OBJECTIVE

Prescription opioid misuse has led to a new cohort of opioid use disorder (OUD) patients who were introduced to opioids through a legitimate prescription. This change has caused a shift in the demographic profile of OUD patients from predominantly young men to middle age and older people. The management of OUD includes medication-assisted treatment (MAT), which produces varying rates of treatment response. In this study, we will examine whether the source of first opioid use has an effect on treatment outcomes in OUD. Using a systematic review of the literature, we will investigate the association between source of first opioid introduction and treatment outcomes defined as continuing illicit opioid use and poly-substance use while in MAT.

METHODS

Medline, EMBASE, CINHAL, and PsycInfo were searched from inception to December 31st, 2019 inclusive using a comprehensive search strategy. Five pairs of reviewers conducted screening and data extraction independently in duplicate. The review is conducted and reported according to the PRISMA guidelines. A random-effects model was used for meta analyses assuming heterogeneity among the included studies.

RESULTS

The initial search results in 27,345 articles that were screened, and five observational studies were included in the qualitative and quantitative analyses. Our results found that those who were introduced to opioids through a legitimate prescription were significantly less likely to have illicit opioid use (0.70, 95% CI 0.50, 0.99) while on MAT. They were also less likely to use cannabis (0.54, 95% CI 0.32, 0.89), alcohol (0.75, 95% CI 0.59, 0.95), cocaine (0.50, 95% CI 0.29, 0.85), and injection drug use (0.25, 95% CI 0.14, 0.43) than those introduced to opioids through recreational means.

CONCLUSION

This study shows that the first exposure to opioids, whether through a prescription or recreationally, influences prognosis and treatment outcomes of opioid use disorder. Although the increased pattern of prescribing opioids may have led to increased OUD in a new cohort of patients, these patients are less likely to continue to use illicit drugs and have a different prognostic and clinical profile that requires a tailored approach to treatment.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017058143.

Safe and Appropriate Use of Methadone in Hospice and Palliative Care: Expert Consensus White Paper

Methadone has several unique characteristics that make it an attractive option for pain relief in serious illness, but the safety of methadone has been called into question after reports of a disproportionate increase in opioid-induced deaths in recent years. The American Pain Society, College on Problems of Drug Dependence, and the Heart Rhythm Society collaborated to issue guidelines on best practices to maximize methadone safety and efficacy, but guidelines for the end-of-life scenario have not yet been developed. A panel of 15 interprofessional hospice and palliative care experts from the U.S. and Canada convened in February 2015 to evaluate the American Pain Society methadone recommendations for applicability in the hospice and palliative care setting. The goal was to develop guidelines for safe and effective management of methadone therapy in hospice and palliative care. This article represents the consensus opinion of the hospice and palliative care experts for methadone use at end of life, including guidance on appropriate candidates for methadone, detail in dosing, titration, and monitoring of patients' response to methadone therapy.

Mortality risk during and after opioid substitution treatment: systematic review and meta-analysis of cohort studies

Objective To compare the risk for all cause and overdose mortality in people with opioid dependence during and after substitution treatment with methadone or buprenorphine and to characterise trends in risk of mortality after initiation and cessation of treatment.Design Systematic review and meta-analysis.Data sources Medline, Embase, PsycINFO, and LILACS to September 2016.Study selection Prospective or retrospective cohort studies in people with opioid dependence that reported deaths from all causes or overdose during follow-up periods in and out of opioid substitution treatment with methadone or buprenorphine.Data extraction and synthesis Two independent reviewers performed data extraction and assessed study quality. Mortality rates in and out of treatment were jointly combined across methadone or buprenorphine cohorts by using multivariate random effects meta-analysis.Results There were 19 eligible cohorts, following 122 885 people treated with methadone over 1.3-13.9 years and 15 831 people treated with buprenorphine over 1.1-4.5 years. Pooled all cause mortality rates were 11.3 and 36.1 per 1000 person years in and out of methadone treatment (unadjusted out-to-in rate ratio 3.20, 95% confidence interval 2.65 to 3.86) and reduced to 4.3 and 9.5 in and out of buprenorphine treatment (2.20, 1.34 to 3.61). In pooled trend analysis, all cause mortality dropped sharply over the first four weeks of methadone treatment and decreased gradually two weeks after leaving treatment. All cause mortality remained stable during induction and remaining time on buprenorphine treatment. Overdose mortality evolved similarly, with pooled overdose mortality rates of 2.6 and 12.7 per 1000 person years in and out of methadone treatment (unadjusted out-to-in rate ratio 4.80, 2.90 to 7.96) and 1.4 and 4.6 in and out of buprenorphine treatment.Conclusions Retention in methadone and buprenorphine treatment is associated with substantial reductions in the risk for all cause and overdose mortality in people dependent on opioids. The induction phase onto methadone treatment and the time immediately after leaving treatment with both drugs are periods of particularly increased mortality risk, which should be dealt with by both public health and clinical strategies to mitigate such risk. These findings are potentially important, but further research must be conducted to properly account for potential confounding and selection bias in comparisons of mortality risk between opioid substitution treatments, as well as throughout periods in and out of each treatment.

The impact of comorbid psychiatric disorders on methadone maintenance treatment in opioid use disorder: a prospective cohort study

OBJECTIVE

There is a significant interindividual variability in treatment outcomes in methadone maintenance treatment (MMT) for opioid use disorder (OUD). This prospective cohort study examines the impact of comorbid psychiatric disorders on continued illicit opioid use in patients receiving MMT for OUD.

METHODS

Data were collected from 935 patients receiving MMT in outpatient clinics between June 2011 and June 2015. Using linear regression analysis, we evaluated the impact of having a comorbid psychiatric disorder on continued illicit opioid use during MMT, adjusting for important confounders. The main outcome measure was percentage of opioid-positive urine screens for 6 months. We conducted a subgroup analysis to determine the influence of specific comorbid psychiatric disorders, including substance use disorders, on continued illicit opioid use.

RESULTS

Approximately 80% of participants had at least one comorbid psychiatric disorder in addition to OUD, and 42% of participants had a comorbid substance use disorder. There was no significant association between having a psychiatric comorbidity and continuing opioid use (P=0.248). Results from subgroup analysis, however, suggest that comorbid tranquilizer (β=20.781, P<0.001) and cocaine (β=6.344, P=0.031) use disorders are associated with increased rates of continuing opioid use.

CONCLUSION

Results from our study may serve to guide future MMT guidelines. Specifically, we find that cocaine or tranquilizer use disorder, comorbid with OUD, places patients at high risk for poor MMT outcomes. Treatment centers may choose to gear more intensive therapy toward such populations.

Alcohol use in opioid agonist treatment

Alcohol misuse among individuals receiving agonist treatment for an opioid use disorder is common and is associated with significant morbidity and mortality. At present, though substantial research highlights effective strategies for the screening, diagnosis and management of an alcohol or opioid use disorder individually, less is known about how best to care for those with a dual diagnosis especially since common treatments for opioid addiction may be contraindicated in a setting of alcohol use. This review summarizes existing research and characterizes the prevalence, clinical implications and management of alcohol misuse among individuals with opioid addiction. Furthermore, it highlights clinically relevant management strategies in need of future research to advance care for this unique, but important, patient population.

Risk-factors for methadone-specific deaths in Scotland's methadone-prescription clients between 2009 and 2013

AIM

To quantify gender, age-group and quantity of methadone prescribed as risk factors for drugs-related deaths (DRDs), and for methadone-specific DRDs, in Scotland's methadone-prescription clients.

DESIGN

Linkage to death-records for Scotland's methadone-clients with one or more Community Health Index (CHI)-identified methadone prescriptions during July 2009 to June 2013.

SETTING

Scotland's Prescribing Information System and National Records of Scotland.

MEASUREMENTS

Covariates defined at first CHI-identified methadone prescription, and person-years at-risk (pys) thereafter until the earlier of death-date or 31 December 2013. Methadone-specific DRDs were defined as: methadone implicated but neither heroin nor buprenorphine. Hazard ratios (HRs) were assessed using proportional hazards regression.

FINDINGS

Scotland's CHI-identified methadone-prescription cohort comprised 33,128 clients, 121,254 pys, 1,171 non-DRDs and 760 DRDs (6.3 per 1,000 pys), of which 362 were methadone-specific. Irrespective of gender, methadone-specific DRD-rate, per 1,000 pys, was higher in the 35+ age-group (4.2; 95% CI: 3.6-4.7) than for younger clients (1.9; 95% CI: 1.5-2.2). For methadone-specific DRDs, age-related HRs (e.g., 2.9 at 45+ years; 95% CI: 2.1-3.9) were steeper than for all DRDs (1.9; 95% CI: 1.5-2.4); there was no hazard-reduction for females; no gender by age-group interaction; and, unlike for all DRDs, the highest quintile for quantity of prescribed methadone at cohort-entry (>1960mg) was associated with increased HR (1.8; 95% CI: 1.3-2.5).

CONCLUSION

Higher methadone-specific DRD rates in older clients, irrespective of gender, call for better understanding of methadone's pharmaco-dynamics in older, opioid-dependent clients, many with progressive physical or mental ill-health.

Risk of mortality on and off methadone substitution treatment in primary care: a national cohort study

AIM

To assess whether risk of death increases during periods of treatment transition, and investigate the impact of supervised methadone consumption on drug-related and all-cause mortality.

DESIGN

National Irish cohort study.

SETTING

Primary care.

PARTICIPANTS

A total of 6983 patients on a national methadone treatment register aged 16-65 years between 2004 and 2010.

MEASUREMENT

Drug-related (primary outcome) and all-cause (secondary outcome) mortality rates and rate ratios for periods on and off treatment; and the impact of regular supervised methadone consumption.

RESULTS

Crude drug-related mortality rates were 0.24 per 100 person-years on treatment and 0.39 off treatment, adjusted mortality rate ratio 1.63 [95% confidence interval (CI) = 0.66-4.00]. Crude all-cause mortality rate per 100 person-years was 0.51 on treatment versus 1.57 off treatment, adjusted mortality rate ratio 3.64 (95% CI = 2.11-6.30). All-cause mortality off treatment was 6.36 (95% CI = 2.84-14.22) times higher in the first 2 weeks, 9.12 (95% CI = 3.17-26.28) times higher in weeks 3-4, compared with being 5 weeks or more in treatment. All-cause mortality was lower in those with regular supervision (crude mortality rate 0.60 versus 0.81 per 100 person-years) although, after adjustment, insufficient evidence exists to suggest that regular supervision is protective (mortality rate ratio = 1.23, 95% CI = 0.67-2.27).

CONCLUSIONS

Among primary care patients undergoing methadone treatment, continuing in methadone treatment is associated with a reduced risk of death. Patients' risk of all-cause mortality increases following treatment cessation, and is highest in the initial 4-week period.

A systematic review of the cardiotoxicity of methadone

Methadone is one of the most popular synthetic opioids in the world with some favorable properties making it useful both in the treatment of moderate to severe pain and for opioid addiction. Increased use of methadone has resulted in an increased prevalence of its toxicity, one aspect of which is cardiotoxicity. In this paper, we review the effects of methadone on the heart as well as cardiac concerns in some special situations such as pregnancy and childhood.

METHODS

We searched for the terms methadone, toxicity, poisoning, cardiotoxicity, heart, dysrhythmia, arrhythmia, QT interval prolongation, torsade de pointes, and Electrocardiogram (ECG) in bibliographical databases including TUMS digital library, PubMed, Scopus, and Google Scholar. This review includes relevant articles published between 2000 and 2013. The main cardiac effects of methadone include prolongation of QT interval and torsade de pointes. Other effects include changes in QT dispersion, pathological U waves, Taku-Tsubo syndrome (stress cardiomyopathy), Brugada-like syndrome, and coronary artery diseases. The aim of this paper is to inform physicians and health care staff about these adverse effects. Effectiveness of methadone in the treatment of pain and addiction should be weighed against these adverse effects and physicians should consider the ways to lessen such undesirable effects. This article presents some recommendations to prevent heart toxicity in methadone users.

Considerations on the role of buprenorphine in recovery from heroin addiction from a UK perspective

The United Kingdom Drug Strategy emphasises recovery as a key focus in the treatment of drug dependence. A framework for recovery is defined in the Recovery-Orientated Drug Treatment report, written by an expert working group, and comprises four key phases: engagement and stabilisation, including the establishment of treatment goals; preparation for change, involving engagement in psychosocial and pharmacological interventions; active change, including detoxification and medical withdrawal; and completion, including interventions that strengthen community integration. A body of evidence supports the benefits of buprenorphine, a partial agonist at mu opioid receptors, in supporting individualised recovery based on this framework, specifically in relation to the potential for rapid stabilisation, flexibility to transition to other treatment options or achieve abstinence, effective blocking of on-top use of illicit drugs, the treatment of comorbidities through the minimisation of drug-drug interactions, and a good safety profile. In addition, the newer abuse-deterrent formulation of buprenorphine combined with the opioid antagonist naloxone is likely to strengthen recovery-orientated systems of care due to its potential to reduce misuse and diversion. Progress through the recovery journey and the ability to sustain recovery will depend on individual needs and goals and on the amount of recovery capital that individuals have developed.

Benzodiazepines

Benzodiazepines have been in clinical use since the 1960s. Benzodiazepines act through allosteric modulation of the GABA_A receptor to enhance the activity of GABA, an inhibitory neurotransmitter, resulting in a slowing of neurotransmission and sedative and anxiolytic effects. Initially benzodiazepines were thought to have low dependence liability, though over time there has been increasing evidence of benzodiazepine dependence. Benzodiazepines are commonly used to treat anxiety and insomnia, though increasingly they are considered second line treatments for most indications. Concerns about the effects of benzodiazepines on cognition, falls and their implication in opioid related mortality have emerged. Few pharmacological treatments for benzodiazepine dependence have been shown to be effective with gradual taper the most common treatment strategy for benzodiazepine dependence.

Pharmacological treatments for drug misuse and dependence

INTRODUCTION

Substance misuse disorder (DSM-5) remains a major health challenge. Harm reduction is the initial treatment goal, by reducing or eliminating non-prescribed drug use. Eventual abstinence is the ultimate harm reduction goal. However the scope for evidence-based pharmacological interventions remains limited.

AREAS COVERED

The paper takes a pragmatic clinical approach to existing and developing pharmacotherapies for substance misuse. Dependence may be characterised as a cycle with three stages: binge/intoxication, withdrawal/negative affect and preoccupation/anticipation (craving). Each of these stages may be the focus of pharmacotherapeutic intervention, and current literature is discussed which is of relevance to the practising clinician. Dependence on opiates, stimulants, cannabis and prescribed medications including benzodiazepines and the current treatments are addressed.

EXPERT OPINION

Possible pharmacotherapies of the future include anti-craving medications, which are still incompletely understood. Other developments include ultra-long-acting formulations, some of which have already been produced and are being studied or are in early clinical practice. A completely new line of investigation has been drug 'vaccines', whereby the body is stimulated to produce antibodies to, for example, cocaine and nicotine. Despite a number of evidence-based strategies for the treatment of substance misuse disorder, the range of licensed pharmacological treatment choices nevertheless remains narrow.

Research gaps on methadone harms and comparative harms: findings from a review of the evidence for an American Pain Society and College on Problems of Drug Dependence clinical practice guideline

Methadone-associated overdose deaths have dramatically increased. In order to inform an evidence-based clinical practice guideline to improve safety of methadone prescribing, the American Pain Society commissioned a systematic review on various aspects related to methadone safety. We searched Ovid MEDLINE, Cochrane Library, and PsycINFO databases through July 2012 to identify studies that addressed 1 or more of 17 Key Questions related to methadone safety; an update search was performed in 2014 for new studies related to methadone-related overdose and risks related to cardiac arrhythmias. A total of 168 studies met inclusion criteria for the review. The purpose of this article is to highlight critical research gaps in the literature related to methadone safety. These include lack of evidence on risk factors associated with methadone-overdose deaths and adverse events, limited evidence to evaluate the comparative mortality of methadone versus other opioids, insufficient evidence to fully understand the harms associated with methadone use during pregnancy, and insufficient evidence to determine effects of risk mitigation strategies such as electrocardiogram monitoring, strategies for managing patients with prolonged QTc intervals on screening, urine drug testing, alternative dosing regimens for initiation and titration of therapy, and timing of follow-up. Therefore, most guideline recommendations are based on weak evidence. More research is needed to guide safe methadone prescribing practices and decrease the adverse events associated with methadone.

PERSPECTIVE

This article summarizes critical research gaps in the literature related to methadone safety, based on a systematic review commissioned by the American Pain Society. Critical research gaps were identified in a number of areas, highlighting the need for additional research to guide safer prescribing and risk mitigation strategies.

Methadone safety: a clinical practice guideline from the American Pain Society and College on Problems of Drug Dependence, in collaboration with the Heart Rhythm Society

Methadone is used for the treatment of opioid addiction and for treatment of chronic pain. The safety of methadone has been called into question by data indicating a large increase in the number of methadone-associated overdose deaths in recent years that has occurred in parallel with a dramatic rise in the use of methadone for chronic pain. The American Pain Society and the College on Problems of Drug Dependence, in collaboration with the Heart Rhythm Society, commissioned an interdisciplinary expert panel to develop a clinical practice guideline on safer prescribing of methadone for treatment of opioid addiction and chronic pain. As part of the guideline development process, the American Pain Society commissioned a systematic review of various aspects related to safety of methadone. After a review of the available evidence, the expert panel concluded that measures can be taken to promote safer use of methadone. Specific recommendations include the need to educate and counsel patients on methadone safety, use of electrocardiography to identify persons at greater risk for methadone-associated arrhythmia, use of alternative opioids in patients at high risk of complications related to corrected electrocardiographic QTc interval prolongation, careful dose initiation and titration of methadone, and diligent monitoring and follow-up. Although these guidelines are based on a systematic review, the panel identified numerous research gaps, most recommendations were based on low-quality evidence, and no recommendations were based on high-quality evidence.

PERSPECTIVE

This guideline, based on a systematic review of the evidence on methadone safety, provides recommendations developed by a multidisciplinary expert panel. Safe use of methadone requires clinical skills and knowledge in use of methadone to mitigate potential risks, including serious risks related to risk of overdose and cardiac arrhythmias.

Methadone overdose and cardiac arrhythmia potential: findings from a review of the evidence for an American Pain Society and College on Problems of Drug Dependence clinical practice guideline

The number of deaths associated with methadone use increased dramatically in parallel with marked increases in its use, particularly for treatment of chronic pain. To develop a clinical guideline on methadone prescribing to reduce potential harms, the American Pain Society commissioned a review of various aspects related to methadone safety. This article summarizes evidence related to unintentional overdose due to methadone and harms related to cardiac arrhythmia potential. We searched Ovid MEDLINE, the Cochrane Library, and PsycINFO databases through January 2014 for studies assessing harms associated with methadone use; we judged 70 studies to be relevant and to meet inclusion criteria. The majority of studies on overdose and cardiac arrhythmia risk are observational and provide weak evidence on which to base clinical guidelines. In patients prescribed methadone for treatment of opioid dependence, data suggest that mortality benefits related to reduction in illicit drug use outweigh harms. Despite epidemiologic data showing marked increases in the numbers of methadone-related deaths that have been primarily attributed to increased use of methadone for chronic pain, evidence on methadone and mortality risk in this population has been somewhat contradictory. There is some evidence that recent initiation of methadone, psychiatric admissions, and concomitant use of benzodiazepines are associated with a higher risk for overdose. Evidence on cardiac risks is primarily limited to case reports of torsades de pointes, primarily in patients on high doses of methadone, and to studies showing an association between methadone use and prolongation of QTc intervals. Research is needed to understand the effectiveness of dosing methods, electrocardiogram monitoring, and other risk mitigation strategies in patients prescribed methadone.

PERSPECTIVE

This systematic review synthesizes the evidence related to methadone use and risk for overdose and cardiac arrhythmia. Findings regarding the association between methadone use and QTc interval prolongation and risk factors for methadone-associated overdose suggest potential targets for risk mitigation strategies, though research is needed to determine the effectiveness of such strategies at reducing adverse outcomes.

Safe methadone induction and stabilization: report of an expert panel

OBJECTIVES

Methadone is a well-studied, safe, and effective medication when dispensed and consumed properly. However, a number of studies have identified elevated rates of overdose and death in patients being treated with methadone for either addiction or chronic pain. Among patients being treated with methadone in federally certified opioid treatment programs, deaths most often occur during the induction and stabilization phases of treatment. To address this issue, the federal Substance Abuse and Mental Health Services Administration invited the American Society of Addiction Medicine to convene an expert panel to develop a consensus statement on methadone induction and stabilization, with recommendations to reduce the risk of patient overdose or death related to methadone maintenance treatment of addiction.

METHODS

A comprehensive literature search of English-language publications (1979-2011) was conducted via MEDLINE and EMBASE. Methadone Action Group members evaluated the resulting information and collaborated in formulating the consensus statement presented here, which subsequently was reviewed by more than 100 experts in the field.

RESULTS

Published data indicate that deaths during methadone induction occur because the initial dose is too high, the dose is increased too rapidly, or the prescribed methadone interacts with another drug. Therefore, the Methadone Action Group has developed recommendations to help methadone providers avoid or minimize these risks.

CONCLUSIONS

Careful management of methadone induction and stabilization, coupled with patient education and increased clinical vigilance, can save lives in this vulnerable patient population.

Mechanism of autoinduction of methadone N-demethylation in human hepatocytes

BACKGROUND

There is considerable interindividual and intraindividual variability in methadone metabolism and clearance. Methadone dosing is particularly challenging during initiation of therapy, because of time-dependent increases in hepatic clearance (autoinduction). Although methadone N-demethylation is catalyzed in vitro by cytochrome P4502B6 (CYP2B6) and CYP3A4, and clearance in vivo depends on CYP2B6, mechanism(s) of autoinduction are incompletely understood. In this investigation, we determined mechanism(s) of methadone autoinduction using human hepatocytes.

METHODS

Fresh human hepatocytes were exposed to 0.1 to 10 µM methadone for 72 hours. Cells were washed and methadone N-demethylation assessed. CYP2B6, CYP3A4, and CYP3A5 messenger RNA (mRNA), protein expression (by gel-free high-performance liquid chromatography mass spectrometry) and catalytic activity (bupropion hydroxylation and alfentanil dealkylation for CYP2B6 and CYP3A4/5, respectively) were measured. Mechanisms of CYP induction were characterized using pregnane X receptor and constitutive androstane receptor reporter gene assays.

RESULTS

Methadone (10 µM) increased methadone N-demethylation 2-fold, CYP2B6 and CYP3A4 mRNA 3-fold, and protein expression 2-fold. CYP3A5 mRNA was unchanged. CYP2B6 and CYP3A4/5 activities increased 2-fold. Induction by methadone enantiomers (R-methadone versus S-methadone) did not differ. Induction was relatively weak compared with maximum induction by phenobarbital and rifampin. Lower methadone concentrations had smaller effects. Methadone was an agonist for the pregnane X receptor but not the constitutive androstane receptor.

CONCLUSIONS

Methadone caused concentration-dependent autoinduction of methadone N-demethylation in human hepatocytes, related to induction of CYP2B6 and CYP3A4 mRNA expression, protein expression, and catalytic activity. Induction was related to pregnane X receptor but not constitutive androstane receptor activation. These in vitro findings provide mechanistic insights into clinical autoinduction of methadone metabolism and clearance.

Polydrug abuse: a review of opioid and benzodiazepine combination use

This paper reviews studies examining the pharmacological interactions and epidemiology of the combined use of opioids and benzodiazepines (BZDs). A search of English language publications from 1970 to 2012 was conducted using PubMed and PsycINFO(®). Our search found approximately 200 articles appropriate for inclusion in this paper. While numerous reports indicate that the co-abuse of opioids and BZDs is ubiquitous around the world, the reasons for the co-abuse of these medications are not entirely clear. Though the possibility remains that opioid abusers are using BZDs therapeutically to self-medicate anxiety, mania or insomnia, the data reviewed in this paper suggest that BZD use is primarily recreational. For example, co-users report seeking BZD prescriptions for the purpose of enhancing opioid intoxication or "high," and use doses that exceed the therapeutic range. Since there are few clinical studies investigating the pharmacological interaction and abuse liability of their combined use, this hypothesis has not been extensively evaluated in clinical settings. As such, our analysis encourages further systematic investigation of BZD abuse among opioid abusers. The co-abuse of BZDs and opioids is substantial and has negative consequences for general health, overdose lethality, and treatment outcome. Physicians should address this important and underappreciated problem with more cautious prescribing practices, and increased vigilance for abusive patterns of use.

Risk of drug-related mortality during periods of transition in methadone maintenance treatment: a cohort study

This study aims to identify periods of elevated risk of drug-related mortality during methadone maintenance treatment (MMT) in primary care using a cohort of 3,162 Scottish drug users between January 1993 and February 2004. Deaths occurring during treatment or within 3 days after last methadone prescription expired were considered as cases "on treatment." Fatalities occurring 4 days or more after leaving treatment were cases "off treatment." Sixty-four drug-related deaths were identified. The greatest risk of drug-related death was in the first 2 weeks of treatment (adjusted hazard ratio 2.60, 95% confidence interval 1.03-6.56). Risk of drug-related death was lower after the first 30 days following treatment cessation, relative to the first 30 days off treatment. History of psychiatric admission was associated with increased risk of drug-related death in treatment. Increasing numbers of treatment episodes and urine testing were protective. History of psychiatric admission, increasing numbers of urine tests, and coprescriptions of benzodiazepines increased the risk of mortality out of treatment. The risk of drug-related mortality in MMT is elevated during periods of treatment transition, specifically treatment initiation and the first 30 days following treatment dropout or discharge.

The toxicology of homicide offenders and victims: A review

ISSUES

The toxicology of homicide offenders and victims, and homicide as a cause of death among psychoactive substance users.

APPROACH

Review of the toxicology of homicide, and homicide as a cause of death among psychoactive substance users.

KEY FINDINGS

A half or more of offenders are intoxicated by a psychoactive substance at the time of the homicide, with alcohol the most commonly reported substance. Levels of substances among victims are comparable with those seen among perpetrators. Among both offenders and victims, levels of substances far exceed population use. Among substance users, homicide specific mortality rates of substance users far exceed population rates. Reducing rates of alcohol and other drug consumption, at national and individual levels, can be expected to substantially reduce rates of, and risk for, homicide.

CONCLUSIONS AND IMPLICATIONS

Psychoactive substances are strongly associated with homicide. One of the major societal benefits that can be derived from active attempts to reduce alcohol and other drug use are reductions in homicide rates.

Comparison of opiate-primary treatment seekers with and without alcohol use disorder

Many persons seeking opiate treatment present with complex clinical challenges, which may be exacerbated by alcohol misuse. This report details secondary data analyses aggregating treatment-seeking samples across 10 National Institute on Drug Abuse (NIDA) Clinical Trials Network treatment trials to examine alcohol-related characteristics of opiate-primary (OP) clients and compare broad pretreatment characteristics of those with and without an alcohol use disorder (AUD). Analysis of this aggregate OP client sample (n = 1,396) indicated that 38% had comorbid AUD and that a history of alcohol treatment episodes and recent alcohol problems were common. Further, comparisons of OP clients with and without AUD revealed the former were more likely to have had a history of pervasive difficulties in psychosocial functioning. Findings suggest the need for detection of and intervention for alcohol misuse at the outset of opiate treatment and support for the practice of availing medical, psychological, case management, and other support services.

Differential substance abuse patterns distribute according to gender in heroin addicts

This study attempts to analyse potential gender differences among a group of heroin addicts seeking treatment at a university-based medical centre. The central modality of treatment at this centre is the use of methadone maintenance. Among those patients entering this program there seems to be an emerging pattern of males who tend to use heroin as their opiate of choice, and are more likely to combine it with cannabis, while females are more likely to use to street methadone, with adjunctive use of ketamine, benzodiazepines, hypnotic drugs and/or amphetamines. Women are at higher risk of abusing opioids through a pathway of initial prescription painkiller use, and later to resort to street methadone to cope with prescription pain killer addiction. This latter pattern seems to result in an increased risk for fatal accidental overdoses. The use of these longer-acting agents in women may be influenced by psychosocial and hormonal factors.

Methadone deaths: risk factors in pain and addicted populations

Methadone is highly effective in treating opioid dependence, and it is also used as an analgesic for second-line management of chronic pain. However, recent increases in methadone-related deaths have instigated controversy about the use of this medication. In this paper, we evaluate risk factors for methadone mortality in opioid dependent and pain populations and present guidelines for initiating methadone treatment in these two populations to minimize the risk of death. Early research with methadone-maintained patients revealed that methadone fatalities occur primarily due to respiratory arrest during methadone induction and in the context of polysubstance use. Recent reports of methadone deaths emphasize chronic pain populations, methadone-related QTc prolongation, and the possibility of inducing Torsade de pointes (TdP), a potentially fatal ventricular arrhythmia. Retrospective analyses of these deaths show that patients who develop TdP often present with multiple risk factors, including high methadone doses, use of other medications that cause QTc prolongation, and electrolyte abnormalities. To minimize fatalities, guidelines are presented for initiating methadone in opioid treatment and pain populations that consider the drug's pharmacology along with behavioral, medical and psychiatric risk factors.

Alcohol education provided to opioid treatment program patients: results of a nationwide survey

Alcohol-related problems are especially common among opioid treatment program (OTP) patients, suggesting that educating OTP patients about alcohol and its harmful effects needs to be a priority in OTPs. Using data collected in interviews with a nationwide U.S. sample of OTP directors (N = 200) in 25 states, we identified factors that differentiate OTPs that provided this education to all OTP patients from those that did not. Findings indicate that these factors include (1) providing this education in a greater variety of ways, (2) having a larger percent of staff knowledgeable about alcohol-related issues, (3) having a director who views alcohol issues as a high priority, and (4) having a written OTP policy.

Comparing retention in treatment and mortality in people after initial entry to methadone and buprenorphine treatment

AIM To compare retention in treatment and mortality among people entering methadone and buprenorphine treatment for opioid dependence.

DATA SOURCES

The Pharmaceutical Drugs of Abuse System (PHDAS) database records start- and end-dates of all episodes of methadone and buprenorphine treatment in New South Wales, and the National Death Index (NDI) records all reported deaths.

METHODS

Data linkage study. First entrants to treatment between June 2002 and June 2006 were identified from the PHDAS database. Retention in treatment was compared between methadone and buprenorphine. Names were linked to the NDI database, and 'good matches' were identified. Deaths were classified as occurring during induction, maintenance and either post-methadone or post-buprenorphine, depending on the latest episode of treatment prior to death. The numbers of inductions into treatment, of total person-years spent in each treatment, and person-years post-methadone or buprenorphine, were calculated. Risk of death in different periods, and different treatments, was analysed using Poisson regression.

RESULTS

A total of 5992 people entered their first episode of treatment-3349 (56%) on buprenorphine, 2643 on methadone. Median retention was significantly longer in methadone (271 days) than buprenorphine (40 days). During induction, the risk of death was lower for buprenorphine (relative risk = 0.114, 95% confidence interval = 0.002-0.938, P = 0.02, Fisher's exact test). Risk of death was lowest during treatment, significantly higher in the first 12 months after leaving both methadone and buprenorphine. Beyond 12 months after leaving treatment, risk of death was non-significantly higher than during treatment.

CONCLUSIONS

Buprenorphine was safer during induction. Despite shorter retention in treatment, buprenorphine maintenance was not associated with higher risk of death.

Effects of heroin-assisted treatment on alcohol consumption: findings of the German randomized controlled trial

Alcohol has been suggested to be a risk factor for opioid-dependent patients in methadone maintenance treatment (MMT). Literature shows that MMT has limited effects on alcohol use. Nevertheless, a decrease in alcohol use was detected in the Swiss heroin-assisted treatment (HAT) study. In this article, we carry out an in-depth analysis of the German HAT trial with the aim of determining whether alcohol use was affected among patients undergoing HAT and MMT. Analysis was carried out using self-reported data on consumption units of alcohol used (CU), Addiction Severity Index composite scores (ASI CSs), and carbohydrate-deficient transferrin (CDT) measures. Results suggest significant reduction of CU and CDT in both groups, yet larger effects in the HAT group. ASI CS significantly decreased in the HAT but not in the MMT group. The greater benefit of HAT in reducing alcohol use may be due to the greater daily frequency of dispensing heroin coupled with a requirement of sobriety at each dosing occasion.

Opioid maintenance therapy suppresses alcohol intake in heroin addicts with alcohol dependence: preliminary results of an open randomized study

An open randomized study lasting 12 months was performed to evaluate the efficacy of methadone or buprenorphine to suppress alcohol use in two hundred and eighteen heroin addicts with alcohol dependence. Daily maintenance doses of methadone were 80, 120, 160, and 200 mg/day, while doses of buprenorphine were 8, 16, 24, and 32 mg/day. As expected, both treatments were able to reduce both heroin use and addiction severity (measured with ASI interview). However, although both medications were able to suppress alcohol use, the highest dose of buprenorphine was better than the highest dose of methadone, in reducing alcohol craving, ethanol intake (measured as daily number of drinks), and the ASI subscale of alcohol use. The mechanism underlying the effects of the opioid maintenance therapy on the reduction of alcohol intake is still unclear. The results of the present study may represent the first clinical evidence of the potential effective use of the highest doses of buprenorphine for the suppression of ethanol intake in heroin addicts with alcohol dependence.

Estimating heroin epidemics with data of patients in methadone maintenance treatment, collected during a single treatment day

AIMS

Effects of differing drug policies are difficult to evaluate, because time trends in the spread of heroin use, the most problematic illicit drug world-wide, are unknown in almost all countries. We aimed to develop a simple method to estimate these dynamics with data that can be gathered from patients in substitution treatment within a single day.

DESIGN

We tested the assumption that being in substitution treatment on any day depends solely upon individual time since onset of regular heroin use (following a 'general inclusion function'). We used data from the case register for substitution treatments in the canton of Zurich (1992--2004), comprising 9518 patients, to model a 'general inclusion function'. Applying this function, we calculated 30 incidence curves for heroin dependence, each with data of one of 30 randomly chosen treatment days between 1992 and 2004.

FINDINGS

Incidence modelling led to 30 similar curves, and therefore our hypothesis was corroborated. Additionally, our approach also revealed a restricted access to substitution treatment in the early 1990s and a decline in demand due to the introduction of heroin-assisted treatment from 1994 onwards.

CONCLUSIONS

In the canton of Zurich, the probability of being in substitution treatment can be described by a 'general inclusion function', and therefore dynamics of heroin epidemics can be estimated based on data of a single treatment day. Adaptation of our function to areas with a more restricted access to substitution treatment may permit these estimations also in other regions or countries. Thus, our approach facilitates the urgently needed assessment of the effects of different drug policies.

Methadone toxicity fatalities: a review of medical examiner cases in a large metropolitan area

Over the past several years, Medical Examiners in Kentucky and around the nation have observed a dramatic rise in drug intoxication deaths involving the prescription medication methadone. This documented rise in methadone-related deaths requires a better understanding of methadone's pathophysiology and the ways it contributes to significantly increase morbidity and mortality. This study reviews 176 fatalities ascribed to methadone toxicity by the Office of the Chief Medical Examiner in Kentucky between 2000 and 2004. Postmortem toxicological analysis recorded a more than 10-fold increase in methadone toxicity fatalities, rising from 6 cases in 2000 to 68 cases in 2003. Of the 176 methadone-related fatalities, methadone was the only drug detected in postmortem blood and urine toxicological analyses in 11 (6.25%) cases. The mean methadone blood concentration of all 176 cases was 0.535 mg / L (0.02-4.0). The following psychoactive medications were detected: antidepressants (39.8%), benzodiazepines (32.4%), and other opioids in addition to methadone (27.8%). Cannabinoids were detected in 44 (28.4%) cases and cocaine or metabolite in 34 (21.9%) cases. Of the 95 cases with a known history of methadone use, 46 (48.4%) involved prescription by private physician. The interpretation of blood methadone concentrations alone or combined with other psychoactive drugs requires consideration of the subject's potential chronic use of and tolerance to the drug. A thorough investigation into the practices of procurement and use/abuse of methadone is essential to arrive at the proper designation of the cause of death.