A review of methadone deaths between 2001 and 2005 in Victoria, Australia

Initiation and rapid titration of methadone and slow-release oral morphine (SROM) in an acute care, inpatient setting: a case series

BACKGROUND

Methadone titration in an outpatient setting typically involves initiation with subtherapeutic doses with slow titration to mitigate the risks of respiratory depression and overdose. In pregnancy, and generally, subtherapeutic doses of methadone and slow titrations are associated with poorer outcomes in terms of treatment retention and ongoing illicit opioid use. We aim to describe rapid titration of OAT in an inpatient setting for pregnant injection opioid users with high opioid tolerance secondary to a fentanyl-based illicit drug supply.

METHODS

Retrospective case series of patients admitted to a tertiary center with a primary indication of opioid withdrawal and treatment for severe opioid use disorder in pregnancy.

RESULTS

Twelve women received rapid methadone titrations with or without slow-release oral morphine for opioid use disorder during a total of fifteen hospital admissions. All women included in the study were active fentanyl users (12/12). Methadone dosing was increased rapidly with no adverse events with a median dose at day 7 of 65 mg (IQR 60-70 mg) and median discharge dose of 85 mg (IQR 70-92.5 mg) during their admission for titration. Slow-release oral morphine was used in half of the titration admissions (8/15) with a median dose of 340 mg (IQR 187.5-425 mg) at discharge. The median length of admission was 12 days (IQR 9.5-15).

CONCLUSIONS

A rapid titration of methadone was completed in an inpatient setting with or without slow-release oral morphine, without adverse events showing feasibility of this protocol for a pregnant population in an inpatient setting. Patients achieved therapeutic doses of methadone (and/or SROM) faster than outpatient counterparts with no known adverse events.

[Bronchial diseases and heroin use. A systematic review]

INTRODUCTION

Heroin use can cause respiratory complications including asthma, chronic obstructive pulmonary disease (COPD) and bronchiectasis (BD).

OBJECTIVES

A general review of the literature presenting the data on the relationships between heroin consumption and bronchial complications, while underlining the difficulties of diagnosis and management.

DOCUMENTARY SOURCES

Medline, 1980-2022, keywords "asthma" or "bronchospasm" or "COPD" or "bronchiectasis" and "heroin" or "opiate" or "opiates", with limits pertaining to "Title/Abstract". Concerning asthma, 26 studies were included, as were 16 for COPD and 5 for BD.

RESULTS

Asthma and COPD are more prevalent among heroin addicts, who are less compliant than other patients with their treatment. The authors found a positive association between frequency of asthma exacerbations, admission to intensive care and heroin inhalation. Late diagnosis of COPD worsens the course of the disease; emphysema and BD are poor prognostic factors.

CONCLUSION

Bronchial diseases in heroin users can be identified by means of respiratory function exploration and chest CT scans. These tests should be performed frequently in view of optimizing their care, which includes their weaning themselves from addictive substances.

Increased lung weight in fatal intoxications is not unique to opioid drugs

Fatal intoxications with opioids are known to be associated with an increased lung weight, as well as with brain and pulmonary edema and urinary retention. However, there is evidence to suggest that fatal intoxications with non-opioid substances are also associated with increased lung weight; however, the latter aspect has not been comprehensively analyzed. To determine to what extent opioid and non-opioid substances are associated with increased lung and brain weight, we studied these organs in cases where the cause of death was attributed to intoxication with a single agent. Using data from cases autopsied at the National Board of Forensic Medicine (NBFM) in Sweden from 2009 through 2019 where the cause of death was attributed to a single substance, we created models of combined lung weight and brain weight. The models used age and sex as predictors as well as nested varying effects for the specific intoxicant and category of intoxicant. Suicidal hanging with negative toxicology cases served as controls. The population majority was male among both intoxications (68%) and controls (83%). The most common single substance group was opioids. All tested substances were associated with heavier lungs than controls, with the largest effect in the opioid group. Our findings show that several substances are associated with increased lung weight and that among intoxication deaths there is no difference in expected brain weight between substances. Hence, heavy lungs, without a reasonable explanation, should prompt a broad toxicological screening.

Current and emerging pharmacotherapies for opioid dependence treatments in adults: a comprehensive update

INTRODUCTION

Opioid use disorder (OUD) is characterized by compulsive opioid seeking and taking, intense drug craving, and intake of opioids despite negative consequences. The prevalence of OUDs has now reached an all-time high, in parallel with peak rates of fatal opioid-related overdoses, where 15 million individuals worldwide meet the criteria for OUD. Further, in 2020, 120,000 opioid-related deaths were reported worldwide with over 75,000 of those deaths occurring within the United States.

AREAS COVERED

In this review, we highlight pharmacotherapies utilized in patients with OUDs, including opioid replacement therapies, and opioid antagonists utilized for opioid overdoses and deterrent of opioid use. We also highlight newer treatments, such as those targeting the neuroimmune system, which are potential new directions for research given the recently established role of opioids in activating neuroinflammatory pathways, as well as over the counter remedies, including kratom, that may mitigate withdrawal.

EXPERT OPINION

To effectively treat OUDs, a deeper understanding of the current therapeutics being utilized, their additive effects, and the added involvement of the neuroimmune system are essential. Additionally, a complete understanding of opioid-induced neuronal alterations and therapeutics that target these abnormalities - including the neuroimmune system - is required to develop effective treatments for OUDs.

Long-lasting agony and failure to provide assistance in a case of mixed methadone-prescription drugs acute intoxication

Methadone overdoses are usually considered "slow" and avoidable deaths. Despite being frequently witnessed, the type and duration of the agonal time are rarely documented and challenging to be reconstructed. Here we report a case in which a young male was found dead in a parked car, shortly after discharge from a compulsory psychiatric treatment. Death scene investigation, clinical records collection, analysis of video recordings from surveillance cameras and private videos, post-mortem examination, GC-MS and LC-MS/MS toxicological analyses were performed and allowed to assess an acute fatal intoxication by methadone and prescription drugs. The case here-in reported is a rare example of a witnessed and recorded prolonged agonal phase due to methadone and drug intoxication, which lasted at least 12 hours. The loss of consciousness and a worsening pattern of respiratory depression, including gasping, were reported by the friends of the victim, but no one called for help, arising the suspect of failure to provide assistance. The possibility of a long-lasting agony with respiratory gasping should be considered in the evaluation of similar intoxication cases.

The utility of lung weight to heart weight ratio as a means to identify suspected drug intoxication deaths in a medico-legal autopsy population

Fatal intoxications are common in a medico-legal autopsy setting and are associated with sparse findings during autopsy. It has been suggested that an increased lung weight may be associated with such fatalities. Previous literature is generally limited to a descriptive approach, including only opioid deaths, and lacking a definition of "heavy" lungs. Our aim was to create a model to identify cases with heavy lungs and to assess the predictive power of "heavy" lungs in identifying cases of different types of fatal intoxications during autopsy in an unselected medico-legal autopsy population. We identified all medico-legal autopsy cases ≥18 years in Sweden from 2000 through 2013. The lung weight to heart weight (LWHW) ratio was calculated. The positive predictive values (PPV) and negative predictive values (NPV) of both lung weight and LWHW ratio were calculated. Mean lung weight was higher in the intoxication group but the predictive power in the individual case was limited. Lung weight to heart weight ratio had better predictive power than lung weight alone, with a PPV of at most 0.15(0.14, 0.16 95% CI), while the NPV was 0.96 (0.95, 0.96 95% CI). The association between fatal intoxication and increased lung weight was positive, regardless of method and cutoffs used. While the PPV was poor, the NPV could reduce suspicion of fatal intoxication in the absence of other information. LHWH ratio is only a probability factor for fatal intoxication; accurate cause of death determination-as always-requires consideration of circumstances, autopsy, and toxicologic findings.

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.

Forensic pathological study of methadone-related deaths in the Genoa (Italy) district: A six-year study

Methadone is a synthetic opioid, a pure agonist of the μ receptor. It is used for opioid maintenance therapy in heroin addiction. In recent years, Italian studies of incidence and prevalence have indicated an increase in the illegal sales of methadone and, consequently, an increase in deaths due to acute methadone intoxication as well. The present review is a prospective-observational study regarding epidemiological and toxicological analyses of methadone-related deaths recorded in the district of Genoa (Italy) from 2013 to 2018. The study includes a list of twenty-six people that have died from methadone toxicity: twenty-two males and four females. The concentration of methadone in the blood samples ranged from 181 to 4058.53 ng/mL, with an average of 964.29 ng/mL. Six subjects tested positive for methadone alone; twenty cases, however, presented drugs or substances in different concentrations in the blood samples. Illegal sales and consumption of methadone have a negative impact on the self-administration therapy of opioid addiction, inducing patients to increase their dosage or sell methadone in order to purchase illegal drugs. As shown in our study, this behaviour is associated with an increase in methadone-related deaths. Accordingly, careful monitoring of dosage administrated to patients is required in order to render the system safer.

Common Opioids Involved in Drug Poisoning Presenting to the Emergency Department: A Cross-sectional Study

Objective:

Opioids poisoning is of the most important cause of mortality. The objective of the study was to compare the demographic factors, clinical manifestations, and outcomes of the most common opioids involved in drug overdose presenting to the Emergency Department.

Methods:

This cross-sectional study was conducted from October 2016 to March 2017 in the Clinical Toxicology Department of the main referral center of the university. All poisoning cases with common opioids were included in the study. Demographic factors, clinical manifestations, and outcome were recorded in a check list. ANOVA, Chi-square or Fisher's exact test, and binary logistic regression analysis were used for outcome prediction.

Findings:

Two hundred and thirty six patients with opioids poisoning were evaluated during the study period. The most common opioids involved in poisoning were methadone (47.9%), tramadol (24.2%), and opium (21.6%). Patients with opium poisoning were older than others (P < 0.0001). The rate of suicide was more in the tramadol group, while the past history of psychological problems was more observed in the methadone group (P < 0.0001). Increasing age (odds ratio [OR], 1.05; 95% confidence interval [CI]: 1.02–1.09; P = 0.05) and addiction (P = 0.01; OR, 7; 95% CI: 1.55–31.52) was associated with an increased complications or death. Also patients with somatic disease had more chance of complications/death (P = 0.04; OR, 3.71; 95% CI: 1.06–12.97). Kind of opioids was not a predictive factor in the outcome of the patients with acute poisoning.

Conclusion:

Age, addiction, and somatic disease should be considered as more important factors in outcome prediction with opioids poisoning, including opium, tramadol, and methadone.

Psychosis and Comorbid Opioid Use Disorder: Characteristics and Outcomes in Opioid Substitution Therapy

Background and Objectives

Substance use disorders are highly prevalent among individuals with psychotic disorders and are associated with negative outcomes. This study aims to explore differences in characteristics and treatment outcomes for individuals with psychotic disorders when compared with individuals with other nonpsychotic psychiatric disorders enrolled in treatment for opioid use disorder (OUD).

Methods

Data were collected from a prospective cohort study of 415 individuals enrolled in outpatient methadone maintenance treatment (MMT). Psychiatric comorbidity was assessed using the Mini-International Neuropsychiatric Interview. Participants were followed for 12 months. Participant characteristics associated with having a psychotic disorder versus another nonpsychotic psychiatric disorder were explored by logistic regression analysis.

Results

Altogether, 37 individuals (9%) with a psychotic disorder were identified. Having a psychotic disorder was associated with less opioid-positive urine drug screens (odds ratio [OR] = 0.97, 95% confidence interval [CI] = 0.95, 0.99, P = .046). Twelve-month retention in treatment was not associated with psychotic disorder group status (OR = 0.73, 95% CI = 0.3, 1.77, P = .485). Participants with psychotic disorders were more likely to be prescribed antidepressants (OR = 2.12, 95% CI = 1.06, 4.22, P = .033), antipsychotics (OR = 3.57, 95% CI = 1.74, 7.32, P = .001), mood stabilizers (OR = 6.61, 95% CI = 1.51, 28.97, P = .012), and benzodiazepines (OR = 2.22, 95% CI = 1.11, 4.43, P = .024).

Discussion and Conclusions

This study contributes to the sparse literature on outcomes of individuals with psychotic disorders and OUD-receiving MMT. Rates of retention in treatment and opioid use are encouraging and contrast to the widely held belief that these individuals do more poorly in treatment. Higher rates of coprescription of sedating and QTc-prolonging medications in this group may pose unique safety concerns.

Prevalence of respiratory conditions among people who use illicit opioids: a systematic review

BACKGROUND AND AIMS

There are growing concerns over the respiratory health of people who use illicit opioids due to high rates of opioid inhalation and tobacco smoking in this group. This study aimed to summarize the evidence relating illicit opioid use with poor respiratory health.

METHODS

A systematic review of the literature on the association between illicit opioid use and respiratory health was undertaken in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance (PROSPERO ID = CRD42017059953). Electronic searches of MEDLINE, Embase, PsycINFO, CINAHL and the Cochrane Library databases were undertaken (English language, published January 1980-November 2018). All study designs excluding case studies were considered. Studies were undertaken in community and hospital settings in the United States (n = 23), United Kingdom (n = 7), Australia (n = 7), the Netherlands (n = 2), Canada (n = 2), Ireland (n = 1), Spain (n = 1) and Iran (n = 1). Measurements of respiratory disease, including asthma and chronic obstructive pulmonary disease (COPD) and related symptoms were extracted. Data on respiratory-related deaths and hospital admissions were also extracted. Meta-analysis of prevalence data was undertaken using a random effects meta-analysis model with parameters estimated using Markov chain Monte Carlo simulation.

RESULTS

Meta-analyses estimated prevalence of asthma in people who inject illicit opioids as 8.5% [95% predictive interval (PrI) = 0.2%, 74.0%] and as 20.2% (95% PrI = 4.2%, 59.2%) in people who inhale illicit opioids. Prevalence of COPD in people who inject illicit opioids was estimated as 2.7% (95% PrI = 0.0%, 50.4%) and as 17.9% (95% PrI = 0.6%, 89.5%) in people who inhale illicit opioids. There was evidence of moderate to extreme heterogeneity across studies.

CONCLUSIONS

There is evidence of increased burden of respiratory diseases in people who use illicit opioids. Due to the heterogeneity of study design and samples, it is difficult to gain accurate estimates of the prevalence of respiratory disease in this population.

Pharmacotherapeutic management of co-morbid alcohol and opioid use

Opioid use disorder (OUD) and alcohol use disorder (AUD) are two highly prevalent substance-related disorders worldwide. Co-use of the substances is also quite prevalent, yet there are no pharmacological treatment approaches specifically designed to treat co-morbid OUD and AUD. Here, the authors critically summarize OUD, AUD and opioid/alcohol co-use and their current pharmacotherapies for treatment. They also review the mechanisms of action of opioids and alcohol within the brain reward circuitry and discuss potential combined mechanisms of action and resulting neuroadaptations. Pharmacotherapies that aim to treat AUD or OUD that may be beneficial in the treatment of co-use are also highlighted. Preclinical models assessing alcohol and opioid co-use remain sparse. Lasting neuroadaptations in brain reward circuits caused by co-use of alcohol and opioids remains largely understudied. In order to fully understand the neurobiological underpinnings of alcohol and opioid co-use and develop efficacious pharmacotherapies, the preclinical field must expand its current experimental paradigms of 'single drug' use to encompass polysubstance use. Such studies will provide insights on the neural alterations induced by opioid and alcohol co-use, and may help develop novel pharmacotherapies for individuals with co-occurring alcohol and opioid use disorders.

The relative lethal toxicity of pharmaceutical and illicit substances: A 16-year study of the Greater Newcastle Hunter Area, Australia

AIMS

We aim to calculate 2 metrics of relative lethal toxicity; the fatal toxicity index (FTI; number of deaths per year of a daily dose) and the case fatality (CF; number of deaths per overdose) with a focus on opioids, antidepressants, antipsychotics, benzodiazepines and illicit drugs.

METHODS

This descriptive cohort study used the Australian National Coronial Information System (NCIS) to identify a population of individuals with drug-associated deaths in the Greater Newcastle Hunter Area between January 2002 and December 2016. This was combined with Australian medicine dispensing data and corresponding data from the Hunter Area Toxicology Service to calculate FTI and CF.

RESULTS

There were 444 drug-related deaths and 21,296 overdoses during the study period. FTI and CF were well correlated (Spearman's rho 0.64, P < .001). Of the classes of interest, opioids had the highest FTI (40.3 95% confidence interval [CI] 35.2-45.4 deaths per 100 years of use at the defined daily dose or deaths/DDD/100 years) and CF (12.4% 95%CI 11.0-13.9). Fentanyl, methadone and morphine had the highest relative fatal toxicity within this class. Tricyclic antidepressants had the highest relative fatal toxicity of all antidepressants (FTI 14.5 95%CI 9.7-19.3 deaths/DDD/100 years and CF 7.1% [95%CI 4.8-9.3]) and benzodiazepines appeared to be more associated with multiple agent deaths than single. Of the illicit drugs, heroin had the highest CF (26.4%, 95%CI 19.1-33.7).

CONCLUSION

Knowledge of relative lethal toxicity is useful to prescribers and medicines and public health policy makers in restricting access to more toxic drugs and may also assist coroners in determining cause of death.

The optimization of methadone dosing whilst treating with rifampicin: A pharmacokinetic modeling study

BACKGROUND

The use of oral methadone in opioid substitution treatment (OST) for the management of opioid use disorder is established clinical practice. Confounding treatment is the increased risks of contracting Mycobacterium tuberculosis, the mainstay treatment of which incorporates the potent CYP 2B6 inducer rifampicin.

METHODS

This study applied pharmacokinetic modelling using virtual clinical trials, to pharmacokinetically quantify the extent and impact of rifampicin-mediated drug-drug interactions (DDI) on methadone plasma concentrations. An R-methadone model was developed and validated against 11 retrospective clinical studies prior to use in all subsequent studies. The aims were to investigate: (i) the impact of the DDI on daily methadone doses of 60 mg, 90 mg and 120 mg; (ii) dose escalation during rifampicin and (iii) dose reduction following rifampicin cessation.

RESULTS

A dose increase to 160 mg daily during rifampicin treatment phases was required to maintain peak methadone plasma concentrations within a derived therapeutic window of 80-700 ng/mL. Dose escalation prior to rifampicin initiation was not required and resulted in an increase in subjects with supra-therapeutic concentrations. However, during rifampicin cessation, a dose reduction of 10 mg every 2 days commencing prior to rifampicin cessation, ensured that most patients possessed a peak methadone plasma concentration within an optimal therapeutic window.

IMPLICATIONS

Rifampicin significantly alters methadone plasma concentrations and necessitates dose adjustments. Daily doses of almost double those used perhaps more commonly in clinical practice are required for optimal plasma concentration and careful consideration of dose reduction strategies would be required during the deinduction phase.

An analysis of issues in the classification and reporting of heroin-related deaths

AIMS

To investigate the extent of variability in the reporting of heroin-related deaths in Victoria, Australia. Additionally, to identify opportunities to improve the accuracy and consistency of heroin-related death reporting by examining variability in the attribution, death certification, classification and coding of heroin-related death cases.

METHODS

Heroin-related deaths in Victoria, Australia during a 2-year period (2012-13) were identified using the National Coronial Information System (NCIS) and used as the 'gold standard' measure in this study. Heroin-related death data from the Australian Institute of Health and Welfare (AIHW) and Australian Bureau of Statistics (ABS) were then compared. Differences in the number of deaths reported as well as the classification and coding assigned to the identified heroin-related death cases were investigated by cross-referencing these data sets and examining the assigned ICD-10 codes.

RESULTS

A total of 243 heroin-related deaths were identified through the NCIS compared with 165 heroin-related deaths reported by the AIHW and assigned the heroin-specific ICD-10 code of T40.1. Forty per cent of all the missed heroin-related death cases resulted from either the attribution of the death to morphine toxicity or with non-specific drug toxicity certification; 30% occurred where the cases had been attributed to heroin but there were irregularities in death certification. Additional missed heroin-related death cases occurred as a result of late initial registration of these deaths to the Registry of Births, Deaths and Marriages, and where these cases were then not assessed by the ABS for classification and coding purposes.

CONCLUSIONS

In Victoria, Australia, in 2012 and 2013, the overall number of heroin-related deaths was under-reported by 32% compared with the number of deaths currently identified by the Australian Bureau of Statistics and reported by the Australian Institute of Health and Welfare.

The impact of opiate substitution treatment on mortality risk in drug addicts: a natural experiment study

Background

Opiate substitution treatment (OST) is the main treatment for people addicted to heroin and other opioid drugs. However, there is limited information on how the delivery of this treatment affects mortality risk.

Objectives

To investigate the associations of mortality risk with periods during treatment and following cessation of treatment, medication type, co-prescription of other medication and dosing regimens during titration and detoxification. The trends with time of prescribed medication, dose and treatment duration were also explored.

Design

Prospective longitudinal observational study.

Setting

UK primary care between 1998 and 2014.

Participants

A total of 12,780 patients receiving methadone, buprenorphine or dihydrocodeine.

Main outcome measures

All-cause mortality relating to 657 deaths and drug-related poisoning relating to 113 deaths.

Data sources

Clinical Practice Research Datalink with linked information on cause of death from the Office for National Statistics.

Results

For both outcomes, the lowest mortality risk was observed after 4 weeks of treatment and the highest risk was observed in the first 4 weeks following cessation of treatment [e.g. for drug-related poisoning, incidence rate ratio (IRR) 8.15, 95% confidence interval (CI) 5.45 to 12.19]. There was evidence that the treatment period risks varied with OST medication. The largest difference in risk was for the first 4 weeks of treatment for both outcomes, with patients on buprenorphine being at lower risk than those on methadone (e.g. for drug-related poisoning, IRR 0.08, 95% CI 0.01 to 0.48). The co-prescription of benzodiazepines was associated with linearly increasing the risk of drug-related deaths by dose (IRR 2.02, 95% CI 1.66 to 2.47), whereas z-drugs (zolpidem, zopiclone and zaleplon) were associated with increased risk of both all-cause (IRR 1.83, 95% CI 1.59 to 2.12) and drug-related (IRR 3.31, 95% CI 2.45 to 4.47) mortality. There was weak evidence that higher initial and final doses were associated with increased all-cause mortality risk. In the first 4 weeks of treatment, the risk increased by 4% for each 5-mg increment in methadone dose (1-mg increase in buprenorphine) (hazard ratio 1.04, 95% CI 1.00 to 1.09). In the first 4 weeks after treatment ceased, a similar increment in final dose increased the risk by 3% (hazard ratio 1.03, 95% CI 0.99 to 1.07). There were too few deaths to evaluate the effects on drug-related poisoning. The proportion of OST patients receiving buprenorphine increased between 1998 and 2006. Median treatment duration was consistently shorter for buprenorphine than for methadone for each year studied (overall median duration of 48 and 106 days, respectively).

Limitations

As this was an observational study, the possibility remains of bias from unmeasured factors, which covariate adjustment and inverse probability weighting can eliminate only partially.

Conclusions

Using buprenorphine as an alternative to methadone may not reduce mortality overall despite resulting in lower IRRs from shorter treatment duration. Clinical guidance needs to consider strengthening warnings about the co-prescription of a range of drugs for OST patients.

Future work

Our analyses need to be replicated using other clinical data sets in the UK and in other countries. New interventions and trials are required to investigate improving the retention of OST patients in primary care.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Postmortem Toxicology of New Synthetic Opioids

One hundred fifteen Americans die every day from opioid overdose. These overdose fatalities have been augmented by the increased availability of potent synthetic opioids, such as fentanyl and its derivatives. The death rate of synthetic opioids, other than methadone, increased by 72.2% from 2014 to 2015, and doubled from 2015 to 2016, situating the USA in the midst of an opioid overdose epidemic. The analytical identification of these opioids in postmortem samples and the correct toxicological data interpretation is critical to identify and implement preventive strategies. This article reviews the current knowledge of postmortem toxicology of synthetic opioids and the chemical and pharmacological factors that may affect drug concentrations in the different postmortem matrices and therefore, their interpretation. These factors include key chemical properties, essential pharmacokinetics parameters (metabolism), postmortem redistribution and stability data in postmortem samples. Range and ratios of concentrations reported in traditional and non-traditional postmortem specimens, blood, urine, vitreous humor, liver and brain, are summarized in tables. The review is focused on fentanyl and derivatives (e.g., acetyl fentanyl, butyryl fentanyl, carfentanil, furanyl fentanyl, 4-methoxybutyrylfentanyl, 4-fluorobutyrylfentanyl, ocfentanil) and non-traditional opioid agonists (e.g., AH-7921, MT-45, U-47700). All of these data are critically compared to postmortem data, and chemical and pharmacological properties of natural opioids (morphine), semi-synthetic (oxycodone, hydrocodone, hydromorphone, and oxymorphone), and synthetic opioids (methadone and buprenorphine). The interpretation of drug intoxication in death investigation is based on the available published literature. This review serves to facilitate the evaluation of cases where synthetic opioids may be implicated in a fatality through the critical review of peer reviewed published case reports and research articles.

Forensic Toxicology Perspectives of Methadone-associated Deaths in Tehran, Iran, a 7-year Overview

Methadone has a long history of pain relief and successful substitute for maintenance treatment in heroin and narcotic addiction. The aim of the study was to assess the trends of methadone-associated deaths in Tehran, Iran, in 2009-2015, from a forensic toxicology point of view. All methadone-associated deaths during this 7-year study period were evaluated according to demographic parameters and forensic toxicology analysis results. Results showed that 1274 cases of methadone-associated deaths were investigated during the study period. The incidence rate of methadone-associated deaths had risen 7.7 times in 2015 in comparison with 2009 (p < 0.05). The majority of cases were men (90.35%), aged from 20 to 40 years. About 80% of cases had shown positive results for other drugs and poisons in combination with methadone. Methamphetamine and tramadol were the most drugs detected in post-mortem samples. Death rates among methadone users in Tehran, Iran, increased year by year during 2009-2015. These findings raise the attention to the concomitant use of drugs with the need for changes in regulation and regulatory policy to restrict access and use of controlled drugs.

Nephrotoxicity of methadone: a systematic review

Background

Methadone is commonly administered for chronic pain relief and treatment of opioid dependence. Concurrent with its increased consumption, toxicities and fatalities have increased. One of the adverse effects of opioid analgesics, including methadone, is that of nephrotoxicity. Opioids can have an effect on renal function through several different mechanisms.

Methods

We searched common bibliographical databases for the terms methadone, toxicity, poisoning, kidney, renal, and nephrotoxicity and summarize our findings in this review.

Results

Methadone can have both direct and indirect effects on the kidney. These effects include rhabdomyolysis (leading to acute kidney injury), volumetric changes, renal lipidosis and amyloidosis, kidney growth during pregnancy, and kidney transplant rejection.

Conclusion

Improved understanding of the effects of methadone on kidney function can promote safer and more confident use of the drug.

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.

Opioid agonist doses for oxycodone and morphine dependence: Findings from a retrospective case series

INTRODUCTION

Use of opioid agonist treatments for prescription opioid (PO) dependence is rapidly increasing. Current guidelines are based on research with heroin users. This study aimed to examine methadone and buprenorphine dose requirements for PO-dependent people.

DESIGN AND METHODS

A retrospective case series of PO-dependent patients entering methadone and buprenorphine treatment. Daily oral morphine equivalent (OME) doses at baseline were calculated using standard dose conversion calculations. Dose conversion tables were used to estimate opioid agonist doses, based on starting dose of PO. Baseline methadone and buprenorphine dose at days 7 and 28 were examined. Linear models were fit to the data.

RESULTS

Participants (n = 44) were 67% male, mean age 41 years (SD 10 years); 69% reported a pain condition. The methadone group (n = 21) had a mean PO dose of 704.5 mg OME (SD 783.5 mg) prior to treatment, and mean methadone dose of 45.3 mg (SD 13.1 mg) at day 7 and 61.6 mg (SD 20.8 mg) at day 28. The buprenorphine group (n = 23) had a mean PO dose of 771.7 mg OME (SD 867.7 mg) prior to treatment, with a mean dose of 14.6 mg (SD 8.3 mg) at day 7 and 18.1 (SD 8.9 mg) at day 28. Linear relationships were not found between OME and opioid agonist dose.

CONCLUSIONS

Opioid agonist dosages varied substantially between individuals, and from predicted dosages based on dose conversion tables. Use of conversion tables to guide selection of opioid agonist dosage may compromise patient safety. [Nielsen S, Bruno R, Degenhardt L, Demirkol A, Lintzeris N. Opioid agonist doses for oxycodone and morphine dependence: Findings from a retrospective case series Drug Alcohol Rev 2017;36:311-316].

Fatal toxicity index of medicinal drugs based on a comprehensive toxicology database

The fatal toxicity index (FTI) is the absolute number of fatal poisonings caused by a particular drug divided by its consumption figure. Consequently, it is a useful measure in evaluating toxicity of the drug and its relevance in fatal poisonings. In this study, we assessed the FTI of medicinal drugs in 3 years (2005, 2009, and 2013) in Finland. As the measure of drug consumption, we used the number of defined daily doses (DDD) per population in each year. There were 70 medicinal drugs in Finland for which the mean FTI expressed as the number of deaths per million DDD over the three study years was higher or equal to 0.1. The Anatomical Therapeutic Chemical (ATC) classification system was used for the classification of the active ingredients of medicinal drugs according to the organ or system which they act on. Of these 70 drugs, 55 drugs (78.6 %) acted on the nervous system (denoted by ATC code N), 11 (15.7 %) on the cardiovascular system (C), three (4.3 %) on the alimentary tract and metabolism (A), and one (1.4 %) on the musculoskeletal system (M). The nervous system drugs consisted of 20 psycholeptics, (ATC code N05), 20 psychoanaleptics (N06), eight analgesics (N02), six antiepileptics (N03), and one other nervous system drug (N07). The highest individual FTIs were associated with the opioids methadone, dextropropoxyphene, oxycodone, tramadol, and morphine; the antipsychotics levomepromazine and chlorprothixene; and the antidepressants doxepin, amitriptyline, trimipramine, and bupropion. Buprenorphine was not included in the study, because most of the fatal buprenorphine poisonings were due to smuggled tablets. A clearly increasing trend in FTI was observed with pregabalin and possibly with bupropion, both drugs emerging as abused substances.

Economic vulnerability of methadone maintenance patients: Implications for policies on co-payment services

BACKGROUND

Co-payment for methadone maintenance treatment (MMT) services is a strategy to ensure the financial sustainability of the HIV/AIDS programs in Vietnam. In this study, we examined health services utilization and expenditure among MMT patients, and further explored factors associated with catastrophic health expenditure among affected households.

METHODS

A multi-site cross-sectional study was conducted among 1016 patients in two epicentres: Hanoi and Nam Dinh province in 2013.

RESULTS

Overall, 8.2% and 28.7% respondents used inpatient and outpatient health care services in the past 12 months apart from receiving MMT. There were 12.8% respondents experiencing catastrophic health expenditure given MMT is provided free-of-charge, otherwise 63.5% patients would suffer from health care costs. MMT integrated with general health or HIV services may encourage health care services utilization of patients. Patients, who were single, lived in the rural, had inpatient care and reported problems in Mobility were more likely to experience catastrophic health expenditure than other patient groups.

CONCLUSIONS

The health care costs are still financially burden to many drug users and remained over the course of MMT that implies the necessity of continuous supports from the program. Scaling-up and decentralizing integrated MMT clinics together with economic empowerments for treated drug users and their families should be prioritized in Vietnam.

Therapeutic and recreational methadone cardiotoxicity

Several classes of drugs have been associated with an increased risk of cardiovascular disease and occurrence of arrhythmias potentially involved in sudden deaths in chronic users even at therapeutic doses. The study presented herein focuses on pathological changes involving the heart possibly due to methadone use. 60 cases were included in the study in total and were divided into three groups (therapeutic methadone users: 20 cases, recreational methadone users: 20 cases, and sudden death group in subjects who had never taken methadone: 20 cases). Autopsies, histology, biochemistry and toxicology were performed in all cases. Macroscopic and microscopic investigation results in therapeutic methadone users were similar to those observed in sudden, unexpected deaths in non-methadone users. In recreational methadone consumers, macroscopic and microscopic examination of the heart failed to provide results consistent with acute or chronic myocardial or coronary damage, thereby corroborating the hypothesis of death most likely following respiratory depression.

Clinical Presentation and the Outcome of Therapy in a Cohort of Patients with Methadone Toxicity in Iran

Background:

Agonist maintenance therapy with methadone is amongst the preferred remedies for treating opioid dependence and is increasingly supported by the regional governments in this part of the world. In this study we have investigated the clinical manifestations and factors affecting the outcome of therapy in patients with methadone poisoning in a Middle-Eastern (Iranian) referral tertiary care University hospital.

Methods:

In this prospective and descriptive-analytic study which was done in a tertiary care and referral University hospital in Iran (2012-2013) all of the admitted patients with a clear and reliable history of methadone poisoning (n=433) were included and demographic data, Clinical status on admission including Glasgow Coma Scale (GCS) score, time elapsed from ingestion to hospital admission, average dose of naloxone used, any history of psychiatric disorder, type of toxic exposure, co ingestion of other medication, hospitalization time and the outcome were recorded and statistically analyzed.

Results:

The average length of hospital stay was 33 ± 26 hours. 80.1% of patients had ingested methadone alone, and 90.3% survived. Complications were pulmonary edema (7%), aspiration pneumonia (1.4%), generalized tonic colonic seizure (0.9%), and renal failure (0.5%). GCS, systolic blood pressure and respiratory rate were lower in fatal cases and GCS had prognostic value for the outcome of therapy in methadone intoxicated patients. Patients with higher GCS on admission had better outcome [OR =0.47 (95% CI: 0.38-0.580); P value< 0.0001].

Conclusion:

Admission time GCS score maybe considered as an important predictor for the outcome of therapy in methadone poisoning.

Characteristics of methadone-related fatalities in Norway

There are currently over 7000 patients enrolled in opioid maintenance treatment (OMT) programs in Norway. A rise in methadone-related deaths proportional to increasing methadone sales over the period 2000-2006 has been observed, but the causative factors for these fatalities have been elusive. In the present study, individual characteristics, methadone concentrations and additional toxicological findings were analyzed. Methadone intoxication deaths (n = 264) were divided into 3 groups according to toxicological findings in whole blood: group 1 - methadone detected alone, or together with one additional drug at low or therapeutic levels, or a low concentration of ethanol (<1 g/L) (n = 21); group 2 - multiple additional drugs/substances detected below lethal levels (n = 175); group 3 - one or more additional drugs/substances detected at lethal levels, or ethanol >3 g/L (n = 55). Methadone blood concentrations in decedents who had been enrolled in OMT were higher than for decedents not in treatment, in all groups. Blood methadone concentrations around 1 mg/L were present in fatal multi-drug intoxications in OMT patients. Results suggest that some patients may be at risk of dying when combining therapeutic concentrations of methadone with other psychoactive substances. Somatic disease was a common finding among deceased OMT patients. Concentrations in methadone users not enrolled in OMT were predominantly between 0.3 and 0.4 mg/L and were not related to the presence of other drugs. However, methadone concentrations below 0.1 mg/L may be associated with intoxication following methadone use, both alone and in combination with other drugs. Younger male users (mean age 34 years) seemed to have a higher susceptibility to methadone intoxication.

Factors associated with illicit methadone injecting in a Canadian setting

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

DISCUSSION AND CONCLUSIONS

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

SCIENTIFIC SIGNIFICANCE

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

Out-of-hospital mortality among patients receiving methadone for noncancer pain

IMPORTANCE

Growing methadone use in pain management has raised concerns regarding its safety relative to other long-acting opioids. Methadone hydrochloride may increase the risk for lethal respiratory depression related to accidental overdose and life-threatening ventricular arrhythmias.

OBJECTIVE

To compare the risk of out-of-hospital death in patients receiving methadone for noncancer pain with that in comparable patients receiving sustained-release (SR) morphine sulfate.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study was conducted using Tennessee Medicaid records from 1997 through 2009. The cohort included patients receiving morphine SR or methadone who were aged 30 to 74 years, did not have cancer or another life-threatening illness, and were not in a hospital or nursing home. At cohort entry, 32 742 and 6014 patients had filled a prescription for morphine SR or methadone, respectively. The patients' median age was 48 years, 57.9% were female, and comparable proportions had received cardiovascular, psychotropic, and other musculoskeletal medications. Nearly 90% of the patients received the opioid for back pain or other musculoskeletal pain. The median doses prescribed for morphine SR and methadone were 90 mg/d and 40 mg/d, respectively.

MAIN OUTCOMES AND MEASURES

The primary study end point was out-of-hospital mortality, given that opioid-related deaths typically occur outside the hospital.

RESULTS

There were 477 deaths during 28 699 person-years of follow-up (ie, 166 deaths per 10 000 person-years). After control for study covariates, patients receiving methadone had a 46% increased risk of death during the follow-up period, with an adjusted hazard ratio (HR) of 1.46 (95% CI, 1.17-1.83; P < .001), resulting in 72 (95% CI, 27-130) excess deaths per 10 000 person-years of follow-up. Methadone doses of 20 mg/d or less, the lowest dose quartile, were associated with an increased risk of death (HR, 1.59; 95% CI, 1.01-2.51, P = .046) relative to a comparable dose of morphine SR (<60 mg/d).

CONCLUSIONS AND RELEVANCE

The increased risk of death observed for patients receiving methadone in this retrospective cohort study, even for low doses, supports recommendations that it should not be a drug of first choice for noncancer pain.

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.

Methadone toxicity in a poisoning referral center

Objective:

Methadone poisoning can occur accidentally or intentionally for suicide or homicide purposes. The aim of this study was to evaluate the epidemiological and clinical manifestations of Methadone poisoning.

Methods:

A descriptive analytical study was performed from 2010 to 2012 in the poisoning emergency and clinical toxicology departments of Noor hospital affiliated with Isfahan University of Medical Sciences (Isfahan, Iran). All patients with Methadone poisoning within this period of time were investigated. Different variables were recorded in a checklist.

Findings:

A total of 385 patients were studied. About 85.7% had ingested only Methadone and 14.3% had ingested other medications with Methadone. Mean ± standard deviation of the age was 32.1 ± 15 years (range: 1-90). Most of the patients were male (76.4%). Nearly 40% of the patients were narcotic addicts, 25.5% were addicts under surveillance of Methadone maintenance therapy centers and 34.5% were non-addicts. Intentional poisoning was observed in most of the patients (57.7%). Most of the patients had a low level of consciousness on admission (58.2%). Respiratory depression and hypotension was observed in 35.6% and 12.7% of the cases as the most common symptoms. Regarding vital signs, there was a significant difference in respiratory rate on admission among different evaluated groups (P = 0.02). Length of hospital stay was 18.79 ± 0.72 h (range: 4-240 h, median: 15 h). About 57 patients (25.8%) from the intentionally poisoned patients and 19 patients (12.3%) from the unintentionally poisoned patients had a history of psychiatric disorder (P = 0.001). Most of the patients survived without complications.

Conclusion:

Addiction, age, gender, attempt to suicide and a history of psychiatric disorder were of the most important factors effective in Methadone poisoning, which should be considered in the public training and prevention of poisoning.

Intravenous methadone application as a serious risk factor for an overdose death: methadone-related fatalities in Hamburg from 2007 to 2012

Methadone plays an increasing role in drug-related deaths in Hamburg. To find out whether intravenous application of methadone plays a relevant role in methadone-related deaths, body fluids of all methadone-positive cases (n=130) and three buprenorphine-positive cases where a urine sample was available (n=58+3) were investigated for disaccharides (sucrose and lactose as markers for intravenous methadone abuse). Sixty-four percent of the urine samples of the methadone cases showed positive results for disaccharides (22 times sucrose alone, range 2 to >1,000 mg/L; 6 times lactose and sucrose; and 9 times lactose alone, range 22 to 382 mg/L). The three buprenorphine cases showed positive results for lactose in urine. In blood, it was not possible to detect any disaccharides. Of the 116 fatal methadone intoxications, 49 % were under opiate maintenance treatment (OMT) at the point of death (A-OMT), 30 % were never in OMT (N-OMT) and 21 % were formerly in an OMT, but not at the point of death (F-OMT). Of the deceased in the OMT group, 12 % (n=7) died within the first 2 weeks of treatment, six of them within the first week. Overall, intravenous abuse of methadone plays a relevant role in methadone-related fatal cases of substituted patients and of drug consumers not in therapy. Thus, it is necessary that therapists keep to the statutory regulations and give take-home doses only after at least 6 months of successful therapy and when there is no suspicion of intravenous abuse.

QTc interval screening for cardiac risk in methadone treatment of opioid dependence

BACKGROUND

Methadone represents today the gold standard of efficacy for the pharmacological treatment of opioid dependence. Methadone, like many other medications, has been implicated in the prolongation of the rate-corrected QT (QTc) interval of the electrocardiogram (ECG), which is considered a marker for arrhythmias such as torsade de pointes (TdP). Indications on the association between methadone, even at therapeutic dosages, and TdP or sudden cardiac death have been reported. On these bases, consensus and recommendations involving QTc screening of patients receiving methadone treatment have been developed to identify patients with QTc above the thresholds considered at risk for cardiac arrhythmias, and they provide these individuals with alternative treatment (reduction of methadone dosage; provision of alternative opioid agonist treatment; treatment of associated risk factors).

OBJECTIVES

To evaluate the efficacy and acceptability of QTc screening for preventing cardiac-related morbidity and mortality in methadone-treated opioid dependents.

SEARCH METHODS

We searched MEDLINE, EMBASE, CINAHL (to April 2013), the Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library Cochrane Drug and Alcohol Review Group Specialised Register (Issue 3, 2013), main electronic sources of ongoing trials, specific trial databases and reference lists of all relevant papers.

SELECTION CRITERIA

Randomised controlled trials (RCTs), controlled clinical trials (CCTs) and non-randomised studies (cohort studies, controlled before and after studies, interrupted time series studies, case control studies) examining the efficacy of QTc screening for the prevention of methadone-related mortality and morbidity in opioid addicts.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened and extracted data from studies.

MAIN RESULTS

The search strategy led to the identification of 872 records. Upon full-text assessment, no study was found to meet the quality criteria used for this review.

AUTHORS' CONCLUSIONS

It is not possible to draw any conclusions about the effectiveness of QTc screening strategies for preventing cardiac morbidity/mortality in methadone-treated opioid addicts. Research efforts should focus on strengthening the evidence about the effectiveness of widespread implementation of such strategies and clarifying the associated benefits and harms.