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

Prescribed and Diverted Methadone Toxicity in South Australia: An Update

ABSTRACT

Methadone is one of the most common medications currently prescribed for the treatment of opioid use disorders (OUDs). While methadone maintenance programs (MMPs) have been highly successful in the management and treatment of OUDs resulting in a reduced number of fatalities, the risk of overdose/toxicity remains. The current study was undertaken to analyze trends in overdoses attributed to prescribed and diverted methadone in South Australia (SA) between 2000 and 2019. Over the 20-year period, 344 methadone-related deaths occurred in SA with a significant increase in deaths over the study period ( P = 0.03). The mean age of decedents was 42.5 years with a male to female ratio of 1.8:1, with approximately 20% of decedents enrolled in a MMP at the time of death. Overall, only 5.2% of cases demonstrated methadone diversion, which was associated with methadone prescribed for chronic pain and was most likely to be diverted from a friend/housemate or a partner. However, the source of methadone in more than half of cases was unknown, so this is likely a significant underestimate of actual MMP methadone diversion and total methadone diversion.

Supervised on-site dosing in injectable opioid agonist treatment-considering the patient perspective. Findings from a cross-sectional interview study in two German cities

BACKGROUND

Injectable opioid agonist treatment (iOAT) is an effective option to support people living with opioid use disorder (OUD) who have not sufficiently benefitted from oral OAT. However, iOAT has been criticised based on theoretical and practical grounds for its dosing policies: Current regulations demand supervised, on-site application and require patients to frequently visit their treatment facility. The current study aims to investigate how patients experience on-site application and derive strategies to enhance the acceptability and effectiveness of iOAT-delivery.

METHODS

This article is based on semi-structured interviews with 27 individuals currently or previously in iOAT in two German outpatient iOAT-clinics. We undertook an inductive qualitative content analysis, which included blinded, independent coding and the analysis of individual cases.

RESULTS

Comments regarding on-site application and daily visits to the clinic were grouped into positive and negative aspects, iOAT as the best alternative option, facilitators of daily visits, and suggestions for improvement. Positive aspects took the factors stability and social support in regard. Negative aspects ranged from general inconveniences to major impediments to individuals' daily lives and towards achieving psychosocial goals. Participants reported rigorous adherence to iOAT's treatment regime, often due to a perceived lack of alternative options. Meeting iOAT's demands was eased by the patients' coping-strategies and through facilitating measures implemented by iOAT-clinics. Despite acknowledgement of the potential detriments from easing regulations, take-home arrangements were frequently suggested by participants to improve iOAT.

CONCLUSIONS

Being required to attend the clinic for supervised iOAT-application is not experienced uniformly. While clinics can support their patients to cope with strict regulations, alternative approaches to iOAT-application should be considered to accommodate patients' individual needs. Examples from other treatment modalities (e.g., remote supervision and delivery services) might aid to reconcile individualisation while providing adequate safety measures and improve iOAT in the long term.

Characteristics and dose-effect relationship of clinical gamma-hydroxybutyrate intoxication: A case series

Gamma-Hydroxybutyrate (GHB) overdoses cause respiratory depression, coma, or even death. Symptoms and severity of poisoning depend on blood-concentrations and individual factors such as tolerance. A retrospective case study was conducted, evaluating GHB intoxication cases. GHB-concentrations in blood and urine were determined by gas chromatography-mass spectrometry (GC-MS) along with, in part, via enzymatic assay. GHB-concentrations, demographic data, and additional drug use, as well as specific clinical information, were evaluated. The correlation between GHB-levels in blood and associated symptoms were examined. In total, 75 cases originating from the Emergency Departments (EDs) of Hamburg and surrounding hospitals were included. Fifty-four of the patients (72%) were male. The mean GHB-concentration in blood was 248 mg/L (range 21.5-1418 mg/L). Out of the group with detailed clinical information (n = 18), the comatose group (n = 10/18) showed a mean of 244 mg/L (range 136-403 mg/L), which was higher than that of the somnolent and awake patients. Of the comatose collective, 70% (n = 7) showed co-use of one or more substances, with the additional use of cocaine being the most frequently detected (n = 5). In conclusion, a moderate dose-effect relationship was observed, although, there was some overlap in dosage concentration levels of GHB in awake and comatose patients. In GHB-intoxication cases, co-use was common as were clinical effects such as acidosis, hypotension, and impact on the heart rate. Timely analytical determination of the GHB-concentration in blood could support correct diagnosis of the cause of unconsciousness.

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.

Methadone-related deaths among youth and young adults in Sweden 2006-15

AIMS

To identify methadone-related deaths and determine the prevalence among youth and young adults in Sweden 2006-15.

DESIGN, SETTING AND PARTICIPANTS

National retrospective registry study comparing data from all forensic autopsy examinations and toxicology cases involving methadone during 2006-15 in individuals aged 15-29 years with police records, previous pharmaceutical prescriptions and health-care episodes.

MEASUREMENTS

Multinomial logistic regression. To assess the factors contributing to the deaths, we compared individuals with and without previous substance use treatment and opioid use-related diagnoses with regard to previous opioid agonist treatment (OAT), psychiatric care and previous pain medication. To assess the circumstances of deaths, we analyzed the presence of other drugs and other factors at time of death.

FINDINGS

We identified 269 methadone-related deaths, and the rate increased during the study period. Seventy-two (27%) cases had not previously received substance use treatment, 112 (42%) had received treatment but had no opioid use-related diagnosis and 85 (32%) had received treatment and had an opioid use-related diagnosis. In total, only 10 individuals had been prescribed methadone during the year before death. Prescriptions of benzodiazepines (60%), antidepressants (62%) and opioids for pain (22%) the year before death were common. Most deaths occurred during sleep with a time lag from ingestion of methadone.

CONCLUSION

Prescription opioid- and methadone-related deaths increased in the group aged 15-29 years in Sweden between 2006 and 2015. Exposure to non-prescribed methadone and prescribed benzodiazepines, antidepressants and opioids for pain appears to be common in drug-related deaths in youth and young adults in Sweden.

Brain/blood ratios of methadone and ABCB1 polymorphisms in methadone-related deaths

Methadone is an opioid that often leads to fatalities. Interpretation of toxicological findings can be challenging if no further information about the case history is available. The aims of this study were (1) to determine whether brain/blood ratios can assist in the interpretation of methadone findings in fatalities; (2) to examine whether polymorphisms in the gene encoding the P-glycoprotein (also known as multidrug resistance protein 1 (MDR1) or ATP-binding cassette sub-family B member 1 (ABCB1)), which functions as a multispecific efflux pump in the blood–brain barrier, affect brain/blood ratios of methadone. Femoral venous blood and brain tissue (medulla oblongata and cerebellum) from 107 methadone-related deaths were analysed for methadone by gas chromatography-mass spectrometry. In addition, all the samples were genotyped for three common ABCB1 single nucleotide polymorphisms (SNPs rs1045642, rs1128503, and rs2032582) using ion-pair reversed-phase high-performance liquid chromatography-electrospray ionization mass spectrometry (ICEMS). In nearly all cases, methadone concentrations were higher in the brain than in the blood. Inter-individual brain/blood ratios varied (0.6–11.6); the mean ratio was 2.85 (standard deviation 1.83, median 2.35). Moreover, significant differences in mean brain/blood ratios were detected among the synonymous genotypes of rs1045642 in ABCB1 (p = 0.001). Cases with the T/T genotype had significantly higher brain/blood ratios than cases with the other genotypes (T/T vs. T/C difference (d) = 1.54, 95% CI [1.14, 2.05], p = 0.002; T/T vs. C/C d = 1.60, 95% CI [1.13, 2.29], p = 0.004). Our results suggest that the rs1045642 polymorphisms in ABCB1 may affect methadone concentrations in the brain and its site of action and may be an additional factor influencing methadone toxicity.

Post-mortem toxicological analyses of blood samples from 107 patients receiving opioid agonist treatment: substances detected and pooled opioid and benzodiazepine concentrations

AIMS

To present the substances and their concentrations detected post-mortem in patients receiving opioid agonist treatment (OAT) stratified by cause of death, estimate the pooled opioid and benzodiazepine concentrations using established conversion factors for blood concentrations from the Norwegian Road Traffic Act, and explore the association between drug-induced cause of death and the pooled opioid and benzodiazepine concentrations.

DESIGN

Cross-sectional nationwide study.

SETTING

Norway.

PARTICIPANTS

One hundred and seven patients who died during OAT (i.e. within 5 days after the last intake of OAT medication) between 1 January 2014 and 31 December 2015, with post-mortem femoral blood available for toxicology. Data were collected from hospital records, the Norwegian Cause of Death Registry and autopsy reports.

MEASUREMENTS

Presence of alcohol and non-alcohol substances in the bloodstream at time of death, determined through records of toxicology of post-mortem femoral blood.

FINDINGS

A median of four substances was detected across the causes of death. At least one benzodiazepine was detected in 81 (76%) patients. The median pooled opioid concentration was significantly higher in drug-induced deaths compared with other causes of death (362 ng/mL versus 182 ng/mL, P < 0.001), in contrast to the pooled benzodiazepine concentration (5466 versus 5701 ng/mL, P = 0.353). The multivariate regression analysis showed that only increasing pooled opioid concentration (ng/ML) was associated with increased odds of a drug-induced cause of death (odds ratio, 1.003; 95% confidence interval: 1.001-1.006).

CONCLUSIONS

In Norway, overall opioid concentration seems to play an important role in drug-induced deaths during opioid agonist treatment in patients prescribed methadone or buprenorphine. Patients prescribed buprenorphine tend to replace their agonist with full agonists, while patients prescribed methadone tend to have high opioid concentrations from methadone as the only opioid.

Increasing diversion of methadone in Vancouver, Canada, 2005-2015

BACKGROUND AND AIM

Although methadone, an opioid agonist, has been an effective medication used to treat opioid use disorder for over 40years, recent studies have found that methadone was identified in more than a quarter of prescription opioid-related deaths among people who use illicit drugs in Vancouver, Canada. Thus, we sought to longitudinally examine the availability of diverted methadone among people who inject drugs (PWID).

DESIGN AND METHODS

Data were collected from three prospective cohorts of PWID in Vancouver, Canada between December 2005 and May 2015. Multivariable generalized estimating equation logistic regression was used to identify temporal trends in the immediate availability of diverted methadone (defined as the ability to acquire illicit methadone in <10min).

RESULTS

A total of 2092 participants, including 727 (34.8%) women, were included in the present study. In the multivariable analyses after adjusting for a range of potential confounders, later calendar year (adjusted odds ratio [AOR]=1.21 per year; 95% confidence interval [CI]: 1.19-1.23) was independently and positively associated with reporting immediate availability of diverted methadone.

CONCLUSIONS

We observed a significant increase in the reported availability of diverted methadone among PWID over a ten-year follow-up period. Further research is needed to identify strategies to limit methadone diversion and assess the impact of alternative medications that are equally effective but safer, such as buprenorphine/naloxone.

Factors associated with non-adherence and misuse of opioid maintenance treatment medications and intoxicating drugs among Finnish maintenance treatment patients

BACKGROUND

The intravenous (IV) use of opioid maintenance treatment (OMT) medications and other intoxicating drugs among OMT patients is a challenge for many OMT units and affects treatment outcomes. The aim of this study is to examine factors associated with IV use of OMT medications and other intoxicating drugs among Finnish OMT patients.

METHODS

A cross-sectional study was conducted among all Finnish OMT patients of whom 60% (n=1508) participated. The data were collected by anonymous questionnaire. Binominal regression analysis with unadjusted and adjusted ORs was conducted to evaluate predictors for IV use.

FINDINGS

Factors associated with the injection of a patient's own OMT medication were: being treated with buprenorphine-naloxone (BNX) (OR 2.60, p=0.005) with a low dose (<9.0mg/day; OR 5.70, p<0.001) and being treated in a health-care centre (OR 2.03, p=0.029). Factors associated with the injection of illicit OMT medications were: being treated with BNX (OR 5.25, p<0.001) with a low dose (<9.0mg/day; OR 2.89, p=0.017), lack of psychosocial support (OR 2.62, p<0.001) and concurrent use of psychotropic medications from illicit sources (OR 4.28, p<0.001). Associated factors for the injection of other intoxicating drugs were: concurrent use of illicit drugs (OR 1.72, p=0.015), psychotropic medications from illicit sources (OR 4.78, p<0.001) and from a doctor (OR 1.93, p=0.004).

CONCLUSIONS

More effort should be made to reduce concurrent injecting use during OMT. This may be done by addressing concurrent substance use orders more effectively, by ensuring that patients receive an optimal BNX dose and by providing more psychosocial support.

Opioid tolerance in methadone maintenance treatment: comparison of methadone and levomethadone in long-term treatment

Background

This study aimed to investigate the development of opioid tolerance in patients receiving long-term methadone maintenance treatment (MMT).

Methods

A region-wide cross-sectional study was performed focusing on dosage and duration of treatment. Differences between racemic methadone and levomethadone were examined. All 20 psychiatric hospitals and all 110 outpatient clinics in Berlin licensed to offer MMT were approached in order to reach patients under MMT fulfilling the DSM IV criteria of opiate dependence. In the study, 720 patients treated with racemic methadone or levomethadone gave information on the dosage of treatment. Out of these, 679 patients indicated the duration of MMT.

Results

Treatment with racemic methadone was reported for 370 patients (54.5 %), with levomethadone for 309 patients (45.5 %). Mean duration of MMT was 7.5 years. We found a significant correlation between dosage and duration of treatment, both in a conjoint analysis for the two substances racemic methadone and levomethadone and for each substance separately. These effects remained significant when only patients receiving MMT for 1 year or longer were considered, indicating proceeding tolerance development in long-term treatment. When correlations were compared between racemic methadone and levomethadone, no significant difference was found.

Conclusions

Our data show a tolerance development under long-term treatment with both racemic methadone and levomethadone. Tolerance development did not differ significantly between the two substances.

The Impact of Misuse and Diversion of Opioid Substitution Treatment Medicines: Evidence Review and Expert Consensus

BACKGROUND/AIMS

Opioid substitution treatment (OST) improves outcomes in opioid dependence. However, controlled drugs used in treatment may be misused or diverted, resulting in negative treatment outcomes. This review defines a framework to assess the impact of misuse and diversion.

METHODS

A systematic review of published studies of misuse and diversion of OST medicines was completed; this evidence was paired with expert real-world experience to better understand the impact of misuse and diversion on the individual and on society.

RESULTS

Direct impact to the individual includes failure to progress in recovery and negative effects on health (overdose, health risks associated with injecting behaviour). Diversion of OST has impacts on a community that is beyond the intended OST recipient. The direct impact includes risk to others (unsupervised use; unintended exposure of children to diverted medication) and drug-related criminal behavior. The indirect impact includes the economic costs of untreated opioid dependence, crime and loss of productivity.

CONCLUSION

While treatment for opioid dependence is essential and must be supported, it is vital to reduce misuse and diversion while ensuring the best possible care. Understanding the impact of OST misuse and diversion is key to defining strategies to address these issues.

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.