Prognostic factors in acute methadone toxicity: a 5-year study

Incidence of rhabdomyolysis occurrence in psychoactive substances intoxication: a systematic review and meta-analysis

Rhabdomyolysis is a potentially life-threatening condition induced by diverse mechanisms including drugs and toxins. We aimed to investigate the incidence of rhabdomyolysis occurrence in intoxicated patients with psychoactive substances. In this review, three databases (PubMed, Scopus, Web of Science) and search engine (Google Scholar) were searched by various keywords. After the screening of retrieved documents, related data of included studies were extracted and analyzed with weighted mean difference (WMD) in random effect model. The highest incidence of rhabdomyolysis was observed in intoxication with heroin (57.2 [95% CI 22.6-91.8]), amphetamines (30.5 [95% CI 22.6-38.5]), and cocaine (26.6 [95% CI 11.1-42.1]). The pooled effect size for blood urea nitrogen (WMD = 8.78, p = 0.002), creatinine (WMD = 0.44, p < 0.001), and creatinine phosphokinase (WMD = 2590.9, p < 0.001) was high in patients with rhabdomyolysis compared to patients without rhabdomyolysis. Our results showed a high incidence of rhabdomyolysis induced by psychoactive substance intoxication in ICU patients when compared to total wards. Also, the incidence of rhabdomyolysis occurrence was high in ICU patients with heroin and amphetamine intoxication. Therefore, clinicians should anticipate this complication, monitor for rhabdomyolysis, and institute appropriate treatment protocols early in the patient's clinical course.

Developing a novel prediction model in opioid overdose using machine learning; a pilot analytical study

Background and Aims

The opioid epidemic has extended to many countries. Data regarding the accuracy of conventional prediction models including the Simplified Acute Physiologic Score (SAPS) II and acute physiology and chronic health evaluation (APACHE) II are scarce in opioid overdose cases. We evaluate the efficacy of adding quantitative electroencephalogram (qEEG) data to clinical and paraclinical data in the prediction of opioid overdose mortality using machine learning.

Methods

In a prospective study, we collected clinical/paraclinical, and qEEG data of 32 opioid-poisoned patients. After preprocessing and Fast Fourier Transform analysis, absolute power was computed. Also, SAPS II was calculated. Eventually, data analysis was performed using SAPS II as a benchmark at three levels to predict the patient's course in comparison with SAPS II. First, the qEEG data set was used alone, secondly, the combination of the clinical/paraclinical, SAPS II, qEEG datasets, and the SAPS II-based model was included in the pool of classifier models.

Results

Seven out of 32 (22%) died. SAPS II (cut-off of 50.5) had a sensitivity/specificity/positive/negative predictive values of 85.7%, 84.0%, 60.0%, and 95.5% in predicting mortality, respectively. Adding majority voting on random forest with qEEG and clinical data, improved the model sensitivity, specificity, and positive and negative predictive values to 71.4%, 96%, 83.3%, and 92.3% (not significant). The model fusion level has 40% less prediction error.

Conclusion

Considering the higher specificity and negative predictive value in our proposed model, it could predict survival much better than mortality. The model would constitute an indicator for better care of opioid poisoned patients in low resources settings, where intensive care unit beds are limited.

Public health risks associated with methadone in Iran: A systematic review and meta-analysis

BACKGROUND

There has been a marked growth in methadone maintenance treatment (MMT) in Iran in the past two decades with positive health outcomes. We conducted a systematic review of studies on the prevalence of non-prescribed methadone use, methadone use disorder, and methadone-related poisoning and mortality in Iran.

METHODS

We searched International and Iranian databases up to May 2020 and contacted relevant experts. The pooled proportions were estimated through random-effects model. Methadone-related adverse outcomes were evaluated over time.

RESULTS

Sixty-five studies were included. The pooled estimates of non-prescribed methadone use in the last 12-month were 2.7% (95%CI: 0.9-5.4) and 0.1% (95%CI: 0.03-0.2) in the male and female general population, respectively. Among people who use drugs, 8.4% reported daily non-prescribed use in 2018. Four heterogeneous studies in drug treatment centers reported the existence of treatment-seeking for methadone use disorder. Methadone was responsible for 10.4% (95%CI: 4.5-18.3) of cases of acute poisoning in adults and 16.0% (95%CI: 9.3-24.1) in children. Methadone was reported as a cause of death in 53.5% of substance-related deaths referred to the Legal Medicine Organization while being the only cause in 35.8% of all cases.

CONCLUSION

Non-prescribed use of methadone in the general population is much less than opiates and some other available prescription opioids, like tramadol. However, notwithstanding the large and successful MMT program in Iran, increasing trends in methadone-related poisoning and deaths pose serious public health concerns. There is an urgent need to explore these fatal and non-fatal poisoning cases and implement policies to curb the harms associated with methadone use.

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.

Clinical characteristics and time trends of hospitalized methadone exposures in the United States based on the Toxicology Investigators Consortium (ToxIC) case registry: 2010-2017

Background

Methadone is well known for its long duration of action and propensity for mortality after an overdose. The present research was aimed at evaluating the clinical manifestations and time trends of methadone exposure in patients in US hospitals.

Methods

We queried the American College of Medical Toxicology’s Toxicology Investigators Consortium case registry for all cases of methadone exposure between January 1, 2010, and December 31, 2017. The collected information included demographic features, clinical presentations, therapeutic interventions, poisoning type (acute, chronic, or acute on chronic), and the reason(s) for exposure. Descriptive data and relative frequencies were used to investigate the participants’ characteristics.

Our data analysis was performed using SPSS version 19 and Prism software. The trends and clinical manifestations of methadone poisoning over the time period of the study were specifically investigated.

Results

Nine hundred and seventy-three patients who met our inclusion criteria, with a mean age of 41.9 ± 16.6 years (range: 11 months-78 years) were analyzed. Five hundred eighty-two (60.2%) were male. The highest rate of methadone poisoning was observed in 2013. There was an increasing rate of methadone exposures in 2010–2013, followed by a decline in 2014–2017. The most common clinical manifestations in methadone-poisoned patients were coma (48.6%) and respiratory depression (33.6%). The in-hospital mortality rate of methadone poisoning was 1.4%.

Conclusion

ToxIC Registry data showed that inpatient methadone exposures enhanced from 2010 to 2013, after which a reduction occurred in the years 2014 to 2017.

Methadone-induced encephalopathy: a case series and literature review

BACKGROUND

Accidental ingestion or consumption of supra-therapeutic doses of methadone can result in neurological sequelae in humans. We aimed to determine the neurological deficits of methadone-poisoned patients admitted to a referral poisoning hospital using brain magnetic resonance (MR) and diffusion weighted (DW) imaging.

METHODS

In this retrospective study, brain MRIs of the patients admitted to our referral center due to methadone intoxication were reviewed. Methadone intoxication was confirmed based on history, congruent clinical presentation, and confirmatory urine analysis. Each patient had an MRI with Echo planar T1, T2, FLAIR, and DWI and apparent deficient coefficient (ADC) sequences without contrast media. Abnormalities were recorded and categorized based on their anatomic location and sequence.

RESULTS

Ten patients with abnormal MRI findings were identified. Eight had acute- and two had delayed-onset encephalopathy. Imaging findings included bilateral confluent or patchy T2 and FLAIR high signal intensity in cerebral white matter, cerebellar involvement, and bilateral occipito-parietal cortex diffusion restriction in DWI. Internal capsule involvement was identified in two patients while abnormality in globus pallidus and head of caudate nuclei were reported in another. Bilateral cerebral symmetrical confluent white matter signal abnormality with sparing of subcortical U-fibers on T2 and FLAIR sequences were observed in both patients with delayed-onset encephalopathy.

CONCLUSIONS

Acute- and delayed-onset encephalopathies are two rare adverse events detected in methadone-intoxicated patients. Brain MRI findings can be helpful in detection of methadone-induced encephalopathy.

Electrocardiographic Findings in Mortalities Due to Pure Methadone Toxicity

We aimed to evaluate electrocardiographic (ECG) abnormalities in mortalities due to pure methadone toxicity in ICU patients since methadone-related mortality may be due to cardiac complications even in acute toxicities. In a retrospective single-center study, files of all patients who had died with confirmed diagnosis of pure methadone toxicity between 2011 and 2016 were evaluated. Autopsy was performed in all cases. A cardiologist measured all ECG quantitative and qualitative indices. Fifty-one deaths were recorded. Forty-two dead patients were males. Median [IQR] age of the patients was 44 [30, 60] years. Of them, 38 (69%) were methadone-dependent and were significantly older than methadone-naïve patients (p = 0.008 and p = 0.001, respectively). ECG abnormalities were detected in all cases. ST-T abnormalities were found in 33 (64.7%) patients. Except longer PR interval in dependent patients (p = 0.017) and specific ST elevation in naïve cases (p = 0.008), other ECG indices were similar in two groups. No correlation was found between ST-T abnormalities and coronary disease in autopsy. ECG abnormalities irrelevant to coronary artery diseases are common in methadone-related mortalities. Methadone toxicity may affect myocardium and play a role in death. Further prospective studies to evaluate other cardiac indices in methadone-poisoned patients are recommended.

Stress Cardiomyopathy (Takotsubo syndrome) Following Accidental Methadone Poisoning; Report of Two Pediatric Cases

Methadone poisoning has become more common in the pediatric population due to extensive use of methadone maintenance therapy (MMT). It is associated with decreased level of consciousness, coma, respiratory distress and cardiac intoxication. The cardiac complications have been reported to be QT prolongation, torsade de pointes, coronary artery disease, arrhythmia, stress cardiomyopathy and death. We herein report two pediatric patients with accidental methadone poisoning who developed stress cardiomyopathy and cardiac failure. The first case was a 4-yaer-old girl and the second one was an 18-month-old girl both being accidentally poisoned with methadone syrup and were brought with decreased level of consciousness. Both were diagnosed to suffer from congestive heart failure based on echocardiography. However, the first case passed away despite appropriate treatment, while the second one survived the condition and was discharged with good condition and was symptom free at 6-month follow-up.

Predictive Factors of Treatment Outcomes for Hospital Care in Children with Acute Methadone Poisoning

OBJECTIVE

The trend of methadone toxicity in children and adolescents seems to be increasing in Iran since it is used as a legal measure of the treatment for opioids addiction in methadone maintenance therapy clinics. In the present study, we describe the clinical and demographical characteristics of acute methadone toxicity in a cohort of pediatric poisoned patients in Isfahan, Iran and discussed the predictive factors for their treatment outcomes.

METHODS

In this 4-year cross-sectional study which was performed from 2013 to 2016 in a referral university hospital (Isfahan, Iran), medical records of the demographic and admission time clinical characteristics of all in-patients aged <18 years with acute methadone poisoning were abstracted and analyzed. According to the outcomes of hospital care and treatment, patients were divided as survived without medical complication and patients survived with at least one medical complication or death.

FINDINGS

A total number of 157 (79 male) children and adolescents with a mean age of 105.4 ± 6.1 months were hospitalized and included in the study. A total of 145 (92.4%) patients survived and discharged from the hospital without any medical complication. Pupil size, respiratory rate, and level of consciousness were predictive factors for the outcome of death or medical complications.

CONCLUSION

It seems that methadone poisoning in children and adolescents is more commonly accidental in school-aged boys (6-12 years old) and it occurs mostly with the syrup dosage form, especially when one of the parents or people who live with the child has an addiction history and if the patients' house located in lower socioeconomic class area of Isfahan city (Iran).

Systematic review of nephrotoxicity of drugs of abuse, 2005-2016

BACKGROUND

The United States is faced with an unprecedented epidemic of drug abuse. Every year thousands of Americans visit the emergency departments all over the country with illicit drug related complaints. These drugs have been known to be associated with a range of renal pathologies, from reversible acute kidney injuries to debilitating irreversible conditions like renal infarction. So far, no comprehensive study or systematic review has been published that includes the commonly used street drugs and designer drugs with potential nephrotoxic outcomes.

METHODS

We conducted a systematic review of published case reports, case series, and cross sectional studies of nephrotoxicities related to drugs of abuse. Literature review was conducted using PubMed/Medline from January 1, 2005 -December 31, 2016 to search for publications related to drug abuse with a defined renal outcome. Publications which reported renal injury in relation to the use of illicit drugs were selected, specifically those cases with raised creatinine levels, clinically symptomatic patients, for instance those with oliguria and proven renal biopsies.

RESULTS

A total of 4798 publications were reviewed during the search process and PRISMA flow chart and Moose protocol regarding systematic reviews were followed. 110 articles were shortlisted for the review. A total of 169 cases from case reports and case series, and 14 case studies were analyzed. Renal manifestations of specific illicit drug abuse were included in this review.

CONCLUSION

Based on the evidence presented, a wide range of renal manifestations were found to be associated with drug abuse. If the trend of increasing use of illicit drug use continues, it will put a significant percentage of the population at an elevated risk for poor renal outcomes. This study is limited by the nature of the literature reviewed being primarily case reports and case series.

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.

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.

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.