Methadone and its role in drug-related fatalities in Cologne 1989-2000

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.

Poly-Drug Use of Prescription Medicine among People with Opioid Use Disorder in China: A Systematic Review and Meta-Analysis

BACKGROUND

Opioid use disorder (OUD) causes substantial public health and social problems worldwide. Poly-drug use is common in people with OUD and increases morbidity and mortality. Investigation of the patterns and characteristics of poly-drug use of prescription medicine among opioid users is needed to develop appropriate prevention and intervention strategies.

OBJECTIVES

To estimate the prevalence of poly-drug use of prescription medicine among people with OUD in China using meta-analysis.

METHODS

We searched relevant epidemiological studies published before February 2017 in English and Chinese databases. The quality of included studies was assessed using the Agency for Healthcare Research and Quality scale. The pooled prevalences of prescription medicine use among people with OUD were estimated.

RESULTS

We included 80 eligible studies in the meta-analysis. The main prescription medicines were benzodiazepines (BZDs) and prescription opioid analgesics. The pooled prevalence of unclassified BZDs and prescription opioids was 40.6% and 23.2%, respectively. Diazepam was the most frequently co-used BZD (32.6%), followed by triazolam (32.1%), and estazolam (9.2%). Tramadol was the most commonly used prescription opioid (27.3%), followed by methadone (16.8%), buprenorphine (12.6%), pethidine (8.9%), morphine (6.5%), dihydroetorphine (3.9%), and codeine-containing cough syrup (3.7%). BZDs were mainly used for self-medication (56.1%), whereas prescription opioids were primarily coused for nonmedical purposes (69.4%).

CONCLUSIONS

The results demonstrate that prescription medicine use is widespread among opioid users in China. There needs to be more consideration of poly-drug use, and early interventions and management strategies are needed to prevent poly-drug use among opioid users in China.

Parent and Metabolite Opioid Drug Concentrations in Unintentional Deaths Involving Opioid and Benzodiazepine Combinations

Effects of benzodiazepines on postmortem opioid parent and parent/metabolite blood concentration ratios were determined for fentanyl-, hydrocodone-, methadone-, or oxycodone-related accidental deaths. These opioids are partially metabolized by the CYP3A4 enzyme system, which is also affected by diazepam and alprazolam. Opioid/metabolite combinations examined were as follows: fentanyl/norfentanyl, hydrocodone/dihydrocodeine, methadone/EDDP, and oxycodone/oxymorphone. Parent opioid concentrations were analyzed for 877 deaths. Parent/metabolite concentration ratios were analyzed for 349 deaths, excluding cases with co-intoxicants present known to interfere with opioid elimination. Alprazolam in combination with diazepam significantly decreased median hydrocodone concentrations by 48% (p = 0.01) compared to hydrocodone alone. The methadone parent/metabolite concentration ratio was reduced by 35% in the presence of diazepam compared to methadone alone (p = 0.03). Benzodiazepines did not statistically significantly affect fentanyl or oxycodone concentrations. Possible factors affecting opioid concentrations and possible toxicity development, including any differential effects on specific opioids, should continue to be explored.

Assessment and Management of Chemical Coping in Patients With Cancer

Chemical coping is a working definition that describes patients' intake of opioids on a scale that spans the range between normal nonaddictive opioid use for pain all the way to opioid addiction. Most patients will fall somewhere between the two extremes in using opioid analgesics to cope with their psychological or spiritual distress. The degree to which patients use their medications in a maladaptive manner will determine their susceptibility to drug toxicity and harm. When there are no obvious cancer-related causes for increased pain intensity, chemical coping and other patient-related factors such as delirium, somatization, and depression should be considered. As part of the initial evaluation of patients with cancer-related pain, a brief screening tool such as the CAGE questionnaire should be used to identify patients who may be at risk for chemical coping. Identifying patients at risk will allow clinicians to avoid unnecessary opioid toxicity, control pain, and improve quality of life. A structured approach for managing opioid use should be adopted, including standardized documentation, opioid treatment agreements, urine drug screens, frequent visits, and restricted quantities of breakthrough opioids. All patients at risk should receive brief motivational interviewing with an objective, nonjudgmental, and empathic style that includes personalized feedback, particularly about markers of risk or harm. For chemical copers approaching the addiction end of the spectrum, with evidence of compulsive use and destructive behavior, referral should be made to substance abuse specialists.

[Fatal methadone poisoning: observations at the CHU of Liege]

All methadone-associated deaths from October 2002 to April 2005 are analysed. A regular increase in these fatal intoxications has been recorded, in Belgium as in other countries, due, in particular, to an intensified prescription of this product, of which illicit use as street dope becomes problematic. Over the 30 months period covered by the study, 26 deaths related to methadone were listed, of which 3 occurred in accidental circumstances. In the other 23 cases, methadone can be found, yet always associated with psychotropic substances, mainly benzodiazepines (18 cases), narcotics (15 cases) and finally alcohol (5 cases). Based upon the nature of the products combined with methadone, records have been divided in two groups: In the first group (17 observations), xenobiotics at (infra)therapeutic levels are detected. In the other group (6 observations), xenobiotics at high and toxic levels are detected. Blood methadone concentrations are not so different between the 2 groups of individuals since the median values and the extreme values are worth respectively 308, and 110-11300 microg/L, for the first group and 776 and 93-2080 microg/L for the second group. There is thus an important overlap between the therapeutic blood methadone concentrations (150-400 microg/L) and blood concentrations observed in fatalities.Thus, it is necessary that all information and post-mortem results must be examined in a critical way to identify and justify cause of the death.

Methadone-related deaths in Montpellier and Region, from 2000 to 2010

PURPOSE

The objectives of this analysis were to assess the role of methadone and related substances in death occurring, discussing methadone blood concentrations and the contribution of the autopsy to the accountability of methadone in the death process.

METHOD

We retrospectively analyzed all forensic cases positive for methadone from January 2000 to December 2010, in Montpellier and the region served by our laboratory.

RESULTS

During the study period, 64 cases of deaths (11 women, 53 men) with methadone detection were recorded. A progressive increase between 2001 (2 cases) and 2010 (8 cases) was observed. The median age was 33 years old. An autopsy was available in 56.3% of cases. The most frequent finding at the autopsy was non-specific asphyxia death signs (67.6%). Tolerance to opioids was documented in 21 cases. The methadone blood concentrations ranged from 1 to 2 800 ng/mL (59 cases, median value 330 ng/mL). Most of the cases (88%) were polydrug intoxications. The most commonly associated drugs were benzodiazepines (61%), cannabinoids (28%), opioids (19%) and cocaine (12.5%).

CONCLUSION

During a 11-year period, toxicological analyses related to 1991 death cases were performed at the Toxicology Laboratory of Montpellier University Hospital. Of these patients, 64 deaths were possibly related to methadone. Several relevant elements (biological analysis and autopsy) were used to attribute the deaths to the sole methadone (12 cases) or to methadone and associated substances (8 cases).

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.

Longitudinal patterns of benzodiazepine consumption in a German cohort of methadone maintenance treatment patients

OBJECTIVE

Cross-sectional studies show that considerable proportions of opiate dependents in methadone maintenance treatment (MMT) consume benzodiazepines (BZD). The longitudinal patterns of BZD use over time were described here.

METHODS

After admission to MMT, patients from two outpatient MMT clinics (n = 345) were observed for up to 2 years whilst in treatment. The use of BZD, cannabis, opiates and cocaine was assessed by urine sampling carried out twice a month.

RESULTS

For the whole sample, the mean BZD-positive urine specimen rate was 0.36 during the first 3 months. Rates slightly decreased during the first year and remained stable afterwards (last observation carried forward). For study completers (n = 152), the rate decreased over time, from 0.31 (first 3-month period) to 0.19 (last period; p < 0.001). According to a longitudinal cluster analysis, 26% of all patients showed a pattern of constantly high BZD-positivity rates, mostly in combination with other substances. Inpatient detoxifications from BZD (carried out in 18% of cases) did not have a sustained effect on levels of BZD use.

CONCLUSIONS

BZD consumption in MMT is often part of a polydrug consumption pattern and is associated with poorer treatment retention. It is necessary to further investigate the reasons for BZD use in MMT patients and to develop effective interventions to reduce levels of BZD consumption.

Pharmacokinetic drug interactions and adverse consequences between psychotropic medications and pharmacotherapy for the treatment of opioid dependence

BACKGROUND

Psychiatric comorbidities among opioid-dependent patients are common. Many medications used to treat both conditions are metabolized through complimentary cytochrome P450 isoenzymes. When medication-assisted treatment for opioid dependence is concurrently used with psychotropic medications, problematic pharmacokinetic drug interactions may occur.

METHODS

We reviewed relevant English language articles identified through the MedLine, Scopus, and Embase databases from 1950 to December 2009 using the specific generic names of medications and keywords such as pharmacokinetics and drug interactions with buprenorphine, methadone, and naltrexone. Selected references from these articles were reviewed. Additionally, a review was conducted of abstracts and conference proceedings from national and international meetings from 1990 to 2009. A total of 60 studies were identified and reviewed.

RESULTS

Clinical case series and carefully controlled pharmacokinetic interaction studies have been conducted between methadone, buprenorphine, or naltrexone and some psychoactive medications. Important pharmacokinetic drug interactions have been demonstrated within each class of medications affecting either methadone and buprenorphine or psychoactive drugs. Few studies, however, have been conducted with naltrexone.

CONCLUSIONS

Several interactions between methadone, buprenorphine, or naltrexone and psychoactive medications are described and may have important clinical consequences. To optimize care, clinicians must be alerted to these interactions.

Trends in methadone-related deaths in Zurich

Methadone has a long and successful history in the treatment of opioid addiction. In recent years, it has become popular again--as potent and inexpensive analgesic in patients with chronic pain. Since methadone has been used fatalities have been reported. In our study all methadone-associated deaths in Zurich from 1998 to 2007 were analysed. Most of the 146 detected deaths of the past 10 years occurred during substitution programmes or illicit intake of methadone while only three of them could be attributed to methadone used as an analgesic. Noticeable in our study was the high percentage of cases of combined drug intoxication (76%). The most frequent co-intoxicants were alcohol and cocaine. Mortalities attributed to methadone intoxication alone were a rare finding and could only be detected in five cases of deceased who had received methadone maintenance treatment. The aim of our study is to assess the trends in the number and nature of methadone-related fatalities in Zurich during the last 19 years. For this purpose a previous study from Zurich (1989-1997) was included, whereby a very long observation period and large number of cases resulted.

Methadone: a new old drug with promises and pitfalls

Although methadone is not a new medication, its use in pain management has increased rapidly over the past decade. This article reviews the unique pharmacologic properties of methadone, including its long-acting nature, highly variable clearance rate, and its antagonism of the N-methyl-D-aspartate receptor. We discuss potential benefits and risks of methadone over other opioid medications. Preclinical studies suggest methadone may reduce abuse potential, tolerance development, and sensitization of nociceptive pathways. Pharmacologic properties of methadone suggest potential greater risk of dangerous or fatal side effects from overdose, QT interval prolongation, and drug interactions. However, clinical studies have yet to confirm that methadone produces either better clinical outcomes or higher rates of adverse events than other opioid analgesics. Clinicians who understand the special properties of methadone and follow recommended precautionary prescribing and monitoring practices can safely and effectively use methadone for pain treatment.

Correlates of illicit methadone use in New York City: a cross-sectional study

BACKGROUND

Despite growing concern about illicit methadone use in the US and other countries, there is little data about the prevalence and correlates of methadone use in large urban areas. We assessed the prevalence and examined correlates of lifetime and recent illicit methadone use in New York City (NYC).

METHODS

1,415 heroin, crack, and cocaine users aged 15-40 years were recruited in NYC between 2000 and 2004 to complete interviewer-administered questionnaires.

RESULTS

In multivariable logistic regression, non-injection drug users who used illicit methadone were more likely to be heroin dependent, less than daily methamphetamine users and to have a heroin using sex partner in the last two months. Injection drug users who used illicit methadone were more likely to use heroin daily, share injection paraphernalia and less likely to have been in a detoxification program and to have not used marijuana in the last six months.

CONCLUSION

The results overall suggest that illicit (or street) methadone use is likely not a primary drug of choice, but is instead more common in concert with other illicit drug use.

Pharmacodynamics of diazepam co-administered with methadone or buprenorphine under high dose conditions in opioid dependent patients

BACKGROUND

Benzodiazepine abuse is common among methadone- and buprenorphine-maintained patients; however interactions between these drugs under high dose conditions have not been adequately examined under controlled conditions.

OBJECTIVE

To investigate the effects of co-administering diazepam with methadone or buprenorphine under high dose conditions.

DESIGN

Double-blind, randomly ordered, 2 x 2 cross-over design in which the effects of diazepam dose (0mg versus 40 mg) and opioid dose (100% versus 150% normal dose) were examined over four sessions in methadone- and buprenorphine-maintained patients.

PARTICIPANTS

Four methadone- and seven buprenorphine-prescribed patients without concurrent dependence on other substances or significant medical co-morbidity.

MEASURES

Physiological (pulse rate, blood pressure, pupil size, respiratory rate and peripheral SpO2), subjective (ARCI, VAS ratings) and performance (reaction time, cancellation task and Digit Symbol Substitution Test, DSST) measures were taken prior to and for 6h post-dosing.

RESULTS

High dose diazepam was associated with time-dependent increases in the intensity of subjective drug effects (strength of drug effect, sedation) and decreases in psychological performance (reaction time, DSST) for both methadone and buprenorphine patients. These effects were generally independent of the opioid dose administered. High dose opioid administration (150% normal dose) was associated with reductions in overall SpO2 levels and performance (reaction time, DSST) in the methadone patients, but had virtually no impact on pharmacodynamic responses in the buprenorphine group.

CONCLUSION

High dose diazepam significantly alters subjective drug responses and psychological performance in patients maintained on methadone and buprenorphine.

Methadone death, dosage and torsade de pointes: risk-benefit policy implications

Methadone maintenance treatment (MMT) for opioid dependency has consistently shown important heath, social and legal benefits. What started as a small experimental program in Lexington, Kentucky has grown and expanded substantially over 35 years. Its practice is now well established both in specialized centers and in the broader community. In society, methadone deaths represent an important issue of public safety: methadone diversion to and ingestion by nontolerant individuals outside of treatment. Within treatment, methadone deaths occur most commonly in the early stabilization period (due to issue of tolerance), in periods of transition, or among certain individuals who abuse other substances (opioids, benzodiazepines, or alcohol). Research suggests moderately high methadone dosages help improve patient retention. Results from pharmacodynamic, kinetic and stereospecific studies continue to support the importance of individualizing dose. For some patients, much larger doses may be necessary to fully achieve all pharmacotherapy goals of treatment. Practitioners must be cautious however as certain patients on higher dosages are predisposed to torsade de pointes and increased mortality. Policymakers have a responsibility in their decision-making to balance the quality of life benefits for patients within MMT with the risks of increased mortality both for individuals within treatment and the general public.

Intoxication-related fatalities in northern Germany

BACKGROUND

Knowing what substances cause death in intoxicated patients is of medical, legal, and political relevance. Harmonized data documentation like TESS (Toxic Exposure Surveillance System) in the United States does not exist yet in Germany. However, the GIZ-Nord Poison Center in Göttingen issues an annual report that includes fatalities. The aim of this study was to obtain an overview of the substances resulting in fatal poisoning and to define risk factors.

METHODS

In a retrospective study, all fatalities due to poisoning from January 1996 until March 2003 were analyzed.

RESULTS

From 1996 to 2003, the GIZ-Nord Poison Center was consulted in 168,000 cases. There were 142 fatalities due to poisoning (0.08% of all consultations). In 79 cases, the lethal substance was a medical drug, mostly tricyclic antidepressants and cardiovascular drugs. Two immigrants of German origin from the former Soviet Union died after consuming Amanita mushrooms. Five elderly, disorientated patients died of respiratory failure due to aspiration of detergent products from soap or shampoo.

CONCLUSION

Three groups of patients with a high risk of dying from intoxication can be defined: (1) suicidal patients with access to tricyclic antidepressants or cardiovascular drugs, (2) immigrants from the former Soviet Union who mistake toxic German mushrooms for edible species, and (3) elderly, disorientated patients who ingest large amounts of soap or shampoo.

Interactions on mixing diazepam with methadone or buprenorphine in maintenance patients

Benzodiazepine use by patients in methadone and buprenorphine substitution treatment is common, despite safety concerns regarding these drug interactions. The relative safety of diazepam use by methadone- or buprenorphine-treated patients has not been systematically examined. This study aimed to examine the effect of single diazepam doses, within normal therapeutic range (doses: 0, 10, and 20 mg), upon physiological, subjective, and performance measures in stable methadone and buprenorphine-treated patients. In a double-blind, randomized crossover design, methadone- or buprenorphine-treated patients were administered their normal opioid dose and either placebo, 10-, or 20-mg diazepam, in balanced order over 3 sessions. Eight methadone- and 8 buprenorphine-prescribed patients with no concurrent benzodiazepine dependence or significant comorbidity were recruited from an outpatient addiction clinic in London. Measures were taken at baseline and for 6 hours after dosing, and included physiological responses (pulse rate, blood pressure, pupil size, respiratory rate, and peripheral pO2), subjective drug effects (Addiction Research Center Inventory subscales, visual analog scales of strength of drug effect, drug-liking, and sedation), and performance measures (simple reaction time, cancellation task, digit symbol substitution task, and balance). The 10- and 20-mg diazepam doses resulted in comparable subjective experiences of greater sedation and strength of drug effects in both patient groups, and had minimal impact on physiological parameters. However, diazepam had greater peak effects on performance measures (simple reaction time, digit symbol substitution task, and cancellation time) in methadone-treated than in buprenorphine-treated patients. Diazepam may significantly alter the response to opioid substitution treatment with methadone or buprenorphine.

Testing positive for methadone and either a tricyclic antidepressant or a benzodiazepine is associated with an accidental overdose death: analysis of medical examiner data

OBJECTIVES

Patients in emergency departments who use methadone frequently use tricyclic antidepressants (TCAs) and/or benzodiazepines (BZDs). This is a potentially dangerous drug combination. The authors hypothesized that the presence of methadone and a TCA, a BZD, or both is associated with an "accidental" overdose (AOD) death more often than a death from any other cause.

METHODS

A retrospective chart review of New York City Office of Chief Medical Examiner data for 2003 was performed. Decedents who tested positive for methadone that were classified as an AOD death, as determined by the medical examiner, were compared with deaths from all other causes for the presence of a TCA, a BZD, or both. A logistical regression was performed to develop a multivariate model identifying additional variables associated with a methadone-positive AOD death. A p-value of <0.05 was considered significant, and 95% confidence intervals (CIs) were calculated.

RESULTS

In 2003, there were 5,817 medical examiner cases, of which 500 (8.6%) were methadone positive. Of the methadone-positive cases, 493 were available for analysis; 95 (19.3%) were TCA positive and 158 (32.0%) were BZD positive. The odds of having an AOD death in methadone-positive decedents testing TCA positive, BZD positive, or both were 2.11 (95% CI = 1.32 to 3.37; p < 0.01) for TCAs, 1.66 (95% CI = 1.12 to 2.45; p < 0.02) for BZDs, and 4.34 (95% CI = 1.97 to 9.56; p < 0.001) for both. The multivariate logistic regression of analytes revealed the following covariates associated with an AOD death as well: amitriptyline, cocaine, morphine, or opiates.

CONCLUSIONS

Among the methadone-positive cases, testing positive for a TCA, a BZD, or both was associated with an AOD death.