Therapeutic and recreational methadone cardiotoxicity

Sudden death during methadone replacement therapy – case report and literature review

Metadon to pochodna difenylopropylaminy, wiążąca się z receptorami opioidowymi, która znalazła zastosowanie w programach leczenia zespołu abstynencji u osób uzależnionych od opioidów oraz w programach substytucyjnych. Celem pracy jest opis przypadku nagłego zgonu osadzonego w trakcie terapii substytucyjnej metadonem z praktyki opiniodawczej autorów oraz przegląd literatury. 41-letni mężczyzna obciążony wieloletnim wywiadem nadużywania substancji psychoaktywnych, zwłaszcza heroiny, odbywający karę pozbawienia wolności, po konsultacji w poradni leczenia uzależnień rozpoczął terapię zastępczą metadonem. W kolejnych dniach przyjął dwie dawki leku (po 50 mg). W nocy podczas obchodu stwierdzono zgon osadzonego. Badania toksykologiczne krwi wykazały obecność metadonu w stężeniu terapeutycznym 816 ng/ml. Obecnie uważa się, że nawet terapeutyczne stężenie metadonu zwiększa ryzyko nagłej śmierci sercowej, zwłaszcza u osób predysponowanych (np. obciążonych patologią strukturalną mięśnia sercowego, zaburzeniami rytmu pracy serca, z hipokaliemią, niewydolnością wątroby). Sudden death during methadone replacement therapy – case report and literature review Methadone is a diphenylpropylamine derivative that binds to opioid receptors and has been used in drug abstinence and substitution treatment programs. The aim of the study is to describe a case of sudden death of a prisoner during methadone substitution therapy from the authors’ medico-legal consulting practice and to review the literature. A 41-year-old male with a long history of abuse of psychoactive substances, especially heroin, serving a prison sentence, after consultation in the addiction treatment clinic, started methadone substitution therapy. In the following days he took two doses of the drug (50 mg each). The prisoner was pronounced dead during the night. Blood toxicology tests showed the presence of methadone at the therapeutic concentration of 816 ng/ml. Currently, it is believed that even the therapeutic concentration of methadone increases the risk of sudden cardiac death, especially in predisposed patients (e.g. with structural pathologies of the myocardium, cardiac arrhythmias, hypokalemia, and liver failure).

Clinical Pharmacology, Toxicity, and Abuse Potential of Opioids

Opioids were the most common drug class resulting in overdose deaths in the United States in 2019. Widespread clinical use of prescription opioids for moderate to severe pain contributed to the ongoing opioid epidemic with the subsequent emergence of fentanyl-laced heroin. More potent analogues of fentanyl and structurally diverse opioid receptor agonists such as AH-7921 and MT-45 are fueling an increasingly diverse illicit opioid supply. Overdose from synthetic opioids with high binding affinities may not respond to a typical naloxone dose, thereby rendering autoinjectors less effective, requiring higher antagonist doses or resulting in a confusing clinical picture for health care providers. Nonscheduled opioid drugs such as loperamide and dextromethorphan are associated with dependence and risk of overdose as easier access makes them attractive to opioid users. Despite a common opioid-mediated pathway, several opioids present with unique pharmacodynamic properties leading to acute toxicity and dependence development. Pharmacokinetic considerations involve half-life of the parent opioid and its metabolites as well as resulting toxicity, as is established for tramadol, codeine, and oxycodone. Pharmacokinetic considerations, toxicities, and treatment approaches for notable opioids are reviewed.

Troponin, A Predictor of Mortality in Methadone Exposure: An Observational Prospective Study

Background

Methadone poisoning/overdose is a global public health problem. We aimed to determine whether methadone poisoning increased cardiac troponin and whether high‐sensitivity cardiac troponin I (hs‐cTnI) levels predicted the need for intensive care unit admission, intubation, and mortality.

Methods and Results

This observational, prospective single‐center study was done at Loghman‐Hakim Hospital (Tehran, Iran) from June 2018 until February 2019. Patients aged >14 years admitted with a diagnosis of methadone exposure were included. Patients were excluded if they had coexisting conditions associated with elevated hs‐cTnI levels. An ECG and hs‐cTnI levels were obtained on emergency department presentation. Patients were followed up on their need for intubation, intensive care unit admission, and in‐hospital mortality. Of 245 included patients (186 [75.9%] men; median age, 33 years), most referred to loss of consciousness (210 cases, 89%). Nineteen (7.7%) patients had hs‐cTnI levels of >0.1 ng/mL (positive), and 41 (16.7%) had borderline levels of 0.019 to 0.1 ng/mL. Twenty‐three (9.3%) cases were admitted to the intensive care unit, 21 (8.5%) needed intubation, and 5 (2%) died during hospitalization. An hs‐cTnI cutoff value of 0.019 ng/mL independently predicted mortality. For optimal concomitant sensitivity and specificity, receiver operating characteristic curve analysis was conducted and showed that hs‐cTnI had an independent significant association with mortality, with a cutoff value of 0.0365 ng/mL (odds ratio, 38.1; 95% CI, 2.3–641.9; P<0.001).

Conclusions

Methadone exposure/toxicity is a newly identified cause of elevated hs‐cTnI. Values >0.019 ng/mL, and particularly >0.0365 ng/mL, of hs‐cTnI predicted mortality in our sample. Future studies should measure troponin levels in methadone maintenance treatment clients to assess the risk of myocardial injury from long‐term exposure.

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.

Opioid-Associated Out-of-Hospital Cardiac Arrest: Distinctive Clinical Features and Implications for Health Care and Public Responses: A Scientific Statement From the American Heart Association

Opioid overdose is the leading cause of death for Americans 25 to 64 years of age, and opioid use disorder affects >2 million Americans. The epidemiology of opioid-associated out-of-hospital cardiac arrest in the United States is changing rapidly, with exponential increases in death resulting from synthetic opioids and linear increases in heroin deaths more than offsetting modest reductions in deaths from prescription opioids. The pathophysiology of polysubstance toxidromes involving opioids, asphyxial death, and prolonged hypoxemia leading to global ischemia (cardiac arrest) differs from that of sudden cardiac arrest. People who use opioids may also develop bacteremia, central nervous system vasculitis and leukoencephalopathy, torsades de pointes, pulmonary vasculopathy, and pulmonary edema. Emergency management of opioid poisoning requires recognition by the lay public or emergency dispatchers, prompt emergency response, and effective ventilation coupled to compressions in the setting of opioid-associated out-of-hospital cardiac arrest. Effective ventilation is challenging to teach, whereas naloxone, an opioid antagonist, can be administered by emergency medical personnel, trained laypeople, and the general public with dispatcher instruction to prevent cardiac arrest. Opioid education and naloxone distributions programs have been developed to teach people who are likely to encounter a person with opioid poisoning how to administer naloxone, deliver high-quality compressions, and perform rescue breathing. Current American Heart Association recommendations call for laypeople and others who cannot reliably establish the presence of a pulse to initiate cardiopulmonary resuscitation in any individual who is unconscious and not breathing normally; if opioid overdose is suspected, naloxone should also be administered. Secondary prevention, including counseling, opioid overdose education with take-home naloxone, and medication for opioid use disorder, is important to prevent recurrent opioid overdose.

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

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

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.

Suspected Methadone Toxicity: from Hospital to Autopsy Bed

High mortality rates have been reported for methadone in both adults and children. We aimed to determine the pattern of toxicity, possible underlying diseases and treatment challenges in patients referred to our centre with early diagnosis of methadone toxicity and who later died. Medical files of all methadone-poisoned patients who had been admitted to a referral centre of toxicology between March 2011 and March 2016, died during the hospital stay and sent for autopsy to Legal Medicine Organization were retrospectively evaluated. In a total of 94 patients, autopsy findings and laboratory evaluations showed that cause of death was pure methadone toxicity in 57 (60.6%). Other causes of death were ischaemic heart disease in ten, co-ingestions (toxicities including methadone) in eight, brain haemorrhage, multi-organ failure and pneumosepsis (each in four), meningitis/encephalitis in three and head trauma and other toxicities (other than methadone but including an opioid, each in two) patients. Time of cardiopulmonary arrest was significantly different between those with pure methadone toxicity and those who died due to other causes (p = 0.01). Patients who had died due to co-ingestions and other toxicities were younger (p = 0.029) and took more bolus doses of naloxone (p = 0.042). In methadone users, especially in older ages and those with trivial response to naloxone administration, loss of consciousness should not be strictly attributed to methadone toxicity. In such patients, thorough evaluation for other possible causes of loss of consciousness is mandatory.