Prospective Memory, Sustained Attention and Response Inhibition in Poly-Substance Users Stable on Methadone Maintenance Treatment

Background: Prospective memory and response inhibition are interrelated constructs, though studied separately in the drug addiction literature. Also, although sustained attention underlies response inhibition, its role in the relation between these functions has been largely neglected. The limited research on the cognitive effects of methadone-maintenance treatment (MMT) further stresses the importance of investigating these effects. Objective: Therefore, the current study focused on possible effects of MMT combined with long-term drug abuse on all these functions. Thirty five long term opiate/poly-substance users in MMT and thirty four drug-free controls were screened for socioeconomic status, anxiety, depression and general, non-verbal intelligence and then tested on a self-report measure of prospective memory and on the Go/No-Go task. Results: Compared to controls, the MMT group scored worse in all functions assessed. Prospective memory scores were also negatively related to Go/NoGo accuracy scores. Conclusion: As predicted, (a) the MMT participants show impairments in prospective memory, sustained attention and response inhibition and (b) prospective memory, response inhibition and sustained attention are related constructs. The results of this study could inform current rehabilitation and relapse prevention cognitive training practices.

In utero methadone exposure permanently alters anatomical and functional connectivity: A preclinical evaluation

The opioid epidemic is an ongoing public health crisis, and children born following prenatal opioid exposure (POE) have increased risk of long-term cognitive and behavioral sequelae. Clinical studies have identified reduced gray matter volume and abnormal white matter microstructure in children with POE but impacts on whole-brain functional brain connectivity (FC) have not been reported. To define effects of POE on whole brain FC and white matter injury in adult animals, we performed quantitative whole-brain structural and functional MRI. We used an established rat model of POE in which we have previously reported impaired executive function in adult rats analogous to persistent neurocognitive symptoms described in humans with POE. Pregnant Sprague-Dawley rat dams received continuous methadone (12 mg/kg/day) vs. saline infusion for 28 days via osmotic mini-pumps, exposing rats to pre- and postnatal opioid until weaning. At young adult age (P60), POE and saline exposed offspring underwent in vivo MRI included diffusion tensor imaging and functional MRI (fMRI). Results indicate that fractional anisotropy (FA) was decreased in adult animals with POE [n = 11] compared to animals that received saline [n = 9] in major white matter tracts, including the corpus callosum (p < 0.001) and external capsule (p < 0.01). This change in FA was concomitant with reduced axial diffusivity in the external capsule (p < 0.01) and increased radial diffusivity in the corpus callosum (p < 0.01). fMRI analyses reveal brainwide FC was diffusely lower in POE (p < 10^-6; 10% of variance explained by group). Decreased connectivity in cortical-cortical and cortico-basal ganglia circuitry was particularly prominent with large effect sizes (Glass's Δ > 1). Taken together, these data confirm POE reduces brainwide functional connectivity as well as microstructural integrity of major white matter tracts. Altered neural circuitry, dysregulated network refinement, and diffuse network dysfunction have been implicated in executive function deficits that are common in children with POE. FC may serve as a translatable biomarker in children with POE.

Race-based differences in drug use prior to onset of opioid use disorder

Rates of opioid use disorder (OUD) have increased dramatically over the past two decades, a rise that has been accompanied by changing demographics of those affected. Early exposure to drugs is a known risk factor for later development of opioid use disorder; but how and whether this risk factor may differ between racial groups is unknown. Our study seeks to identify race differences in self-report of current and past substance use in OUD-diagnosed treatment-seeking individuals. Patients (n = 157) presenting for methadone maintenance treatment at a racially diverse urban opioid treatment program were approached and consented for study involvement. Participants were administered substance use history questionnaires and urine drug screening at intake. Chi-square, t-tests, and rank-sum were used to assess race differences in demographic variables. Logistic and linear regressions assessed the relationship between race and substance use for binary and continuous variables, respectively. 61% of the population identified as Black and 39% as White. Black participants were significantly older; age was thus included as a covariate. Logistic regressions demonstrated that despite similar urine toxicology at intake, White participants were significantly more likely to report having used prescription opioids and psychedelic, stimulant, and sedative substance classes prior to their first use of non-pharmaceutical opioids. Compared to Black participants, White treatment-seeking OUD-diagnosed individuals reported using a wider range of substances ever and prior to first use of non-pharmaceutical opioids. There were no differences, however, in presentation for OUD treatment, suggesting different pathways to OUD, which may carry important clinical implications.

Continuity of illicit drug use among Malay patients attending methadone clinics in Kelantan, Malaysia

The study aimed to determine the prevalence of continuity of illicit drug use and its associated factors among Malay opioid users receiving methadone treatment in Kelantan, Malaysia. This cross-sectional study involved a total of 150 respondents. Sociodemographic characteristic of participants, level of religiosity, and quality of life were collected using the self-administered questionnaires. The prevalence of continuity illicit drug use was 38.7% (n = 58) by self-report and 40.7% (n = 61) by positive urine test result for drugs. Positive hepatitis C status and high quality of life in the psychological health domain were associated with low continuity of illicit drug use by self-reported data and urine drug test results. In conclusion, the continuity of illicit drug use among methadone program users is still high, especially among those on methadone therapy for less than 2 years.

Impact of cannabidiol on reward- and stress-related neurocognitive processes among individuals with opioid use disorder: A pilot, double-blind, placebo-controlled, randomized cross-over trial

Introduction

Opioid use disorder (OUD) continues to be a significant public health concern. Medications for OUD (MOUD) such as buprenorphine reduce overdose mortality, but relapses occur often, leading to adverse outcomes. Preliminary data suggest that cannabidiol (CBD) may be a potential adjunctive treatment to MOUD by attenuating cue-reactivity. This pilot study sought to evaluate the impact of a single dose of CBD on reward- and stress-related neurocognitive processes implicated in relapse among those with OUD.

Methods

The study was a pilot, double-blind, placebo-controlled, randomized cross-over trial aimed at assessing the effects of a single dose of CBD (Epidiolex®) 600 mg or matching placebo administered to participants with OUD receiving either buprenorphine or methadone. Vital signs, mood states, pain, opioid withdrawal, cue-induced craving, attentional bias, decision-making, delayed discount, distress tolerance, and stress-reactivity were examined at each testing session on two separate testing days at least 1 week apart.

Results

Ten participants completed all study procedures. Receipt of CBD was associated with a significant decrease in cue-induced craving (0.2 vs. 1.3, p = 0.040), as well as reduced attentional bias toward drug-related cues as measured by the visual probe task (-80.4 vs. 100.3, p = 0.041). No differences were found among all the other outcomes examined.

Discussion

CBD may have promise as an adjunct to MOUD treatment by attenuating the brain response to drug-related cues, which, in turn, may reduce the risk of relapse and overdoses. Further research is warranted to evaluate the potential for CBD as an adjunctive therapy for individuals in treatment for OUD.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT04982029.

Effects of Methadone on the Toll-like Receptor 4 Expression in Human Non-Small Cell Lung Carcinoma A549 Cell Line Using In-silico and In vitro Techniques

Background

In this study, the effects of methadone and naloxone on the expression of toll-like receptor 4 (TLR4) gene have been evaluated in human non-small cell lung carcinoma A549 cell line migration using in-silico and in vitro techniques.

Materials and Methods

Lung cancer A549 cell cultures were stimulated for 24 h with methadone (5, 10, and 20 μM) and naloxone (20 and 40 μM) concentrations. The level of TLR4 expression was determined by the quantitative real-time polymerase chain reaction. Migration of the A549 cells was investigated after a 4-h incubation period with methadone using the Boyden Chamber assay.

Results

Migration rate of the A549 cells treated with 5 (P < 0.05) and 20 (P < 0.01) μM methadone was, respectively, increased and decreased with 20 μM naloxone (P < 0.05). Furthermore, the TLR4 expression was enhanced with 5 (P < 0.05) and 20 (P < 0.01) μM methadone and decreased with 20 (P < 0.05) and 40 μM naloxone (P < 0.01). In addition, in silico docking analysis revealed docking of methadone to MD-2 and TLR4.

Conclusion

According to the present DATA, methadone affects the TLR4 expression. It may however cause adverse consequences by increasing the TLR4 expression. Therefore, the useful analgesic properties of methadone should be separated from the unwanted TLR4-mediated side effects.

Buprenorphine-naloxone, buprenorphine, and methadone throughout pregnancy in maternal opioid use disorder

INTRODUCTION

Current WHO guidelines recommend using methadone or buprenorphine as maintenance treatments for maternal opioid use disorder. However, buprenorphine-naloxone, with a lower abuse risk than buprenorphine monotherapy or methadone, offers a potentially beneficial alternative, but scientific evidence on its effects on pregnancies, fetuses, and newborns is scarce. This paper compares the outcomes of the pregnancies, deliveries, and newborns of women on buprenorphine-naloxone, buprenorphine, or methadone maintenance treatments. According to the hypothesis, as a maintenance treatment, buprenorphine-naloxone does not have more adverse effects than buprenorphine, whereas methadone is more complicated.

MATERIAL AND METHODS

In this population-based study, 172 pregnant women on medical-assisted treatments were followed-up at Helsinki University Women's Hospital (Finland). Women receiving the same opioid maintenance treatment from conception to delivery and their newborns were included. Consequently, 67 mother-child dyads met the final inclusion criteria. They were divided into three groups based on their opioid pharmacotherapy. The outcomes were compared among the groups and, where applicable, with the Finnish population.

RESULTS

The buprenorphine-naloxone and buprenorphine groups showed similar outcomes and did not significantly differ from each other in terms of maternal health during pregnancies, deliveries, or newborns. Illicit drug use during the pregnancy was common in all groups, but in the methadone group it was most common (p = 0.001). Most neonates (96%) were born full-term with good Apgar scores. They were of relatively small birth size, with those in the methadone group tending to be the smallest. Of the neonates 63% needed pharmacological treatment for neonatal opioid withdrawal syndrome. The need was lower in the buprenorphine-based groups than in the methadone group (p = 0.029).

CONCLUSIONS

Buprenorphine-naloxone seems to be as safe for pharmacotherapy for maternal opioid use disorder as buprenorphine monotherapy for both mother and newborn. Hence it could be a choice for oral opioid maintenance treatment during pregnancy, but larger studies are needed before changing the official recommendations. Women on methadone treatment carry multifactorial risks and require particularly cautious follow up. Furthermore, illicit drug use is common in all treatment groups and needs to be considered for all patients with opioid use disorder.

Gaps in Evidence-based Treatment of Concurrent Attention Deficit Hyperactivity Disorder and Opioid Use Disorder: A Scoping Review

OBJECTIVES

To describe the effectiveness of medications for the treatment of opioid use disorder (OUD) and attention deficit/hyperactivity disorder (ADHD).

DATA SOURCES

Literature search of PubMed, Embase, Web of Science, CINAHL, Medline, PsycINFO, and Google Scholar was performed for studies published from inception to October 25, 2022.

STUDY SELECTION AND DATA EXTRACTION

Studies were included if patients were diagnosed with OUD and ADHD and had pharmacotherapy for either condition. Abstracts, commentaries, reviews, case reports, case series, non-English articles, and animal studies were omitted.

DATA SYNTHESIS

This review found 18 studies. Treatment of ADHD was evaluated for impact on ADHD and OUD outcomes, while treatment of OUD was evaluated for OUD-related outcomes. Outcomes assessed included markers for symptom intensity, adherence, and treatment failure. While results were mixed, treatment of ADHD was largely associated with improvements in ADHD severity and retention in OUD treatment programs. ADHD severity was associated with higher rates of illicit substance abuse and worse OUD-related outcomes. It could not be determined which medications for treatment of OUD should be prioritized.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review summarized key findings from studies that treated ADHD or OUD among dually diagnosed patients and highlighted methodological considerations for future research.

CONCLUSIONS

Treatment of ADHD is warranted among patients with OUD and ADHD to improve retention in OUD treatment programs and reduce illicit substance abuse. Pharmacotherapy for the treatment of ADHD or OUD should continue to be determined based on patients' characteristics and the capabilities of the treatment program.

Perceptions and experiences of patients attending an opioid substitution clinic in South Africa

Background

Opioid substitution therapy (OST) is endorsed as the recommended treatment for opioid use disorders. Opioid substitution therapy is not widely used in South Africa, so little is known about its perceived clinical utility in this setting. There is also a paucity of qualitative research that explores the subjective experiences of patients using OST.

Aim

To explore patients' perceptions and experiences attending a South African OST outpatient clinic (OST-OC).

Setting

The OST-OC at Stikland Psychiatric Hospital, Cape Town, South Africa.

Methods

We conducted a qualitative study using semi-structured interviews with eight participants who had been attending the OST-OC for at least 6 months. Transcripts were analysed using Atlas.ti software and thematic content analysis was used to identify themes.

Results

Patients stated that OST helped them to regain and maintain a stable lifestyle. Autonomy and agency, the therapeutic relationship and family support were perceived as contributing to successful patient outcomes. The preference for methadone and buprenorphine treatment depended on individual experiences. Patients valued kindness from staff members but reported that improved interactions with some nonclinical staff could better facilitate treatment. Challenges experienced included stigma and cost.

Conclusions

This study offers insights about OST that are pertinent to low- and middle-income countries. Reducing the cost of OST, collaborative decision-making between staff and patients, and a non-judgemental attitude by clinical staff were recognised as important factors for optimised service delivery.

Contribution

Understanding patients' experiences of OST in a South African setting will allow for future policy development for the treatment of opioid use disorders in similar settings locally and abroad.

Regular, low-dose methadone for reducing breathlessness in people experiencing or at risk of neurotoxic effects from morphine: A single-center case series

Breathlessness is a common symptom suffered by people living with advanced malignant and non-malignant diseases, one which significantly limits their quality of life. If it emerges at minimal exertion, despite the maximal, guidelines-directed, disease-specific therapies, it should be considered persistent and obliges clinicians to prescribe symptomatic, non-pharmacological, and pharmacological treatment to alleviate it. Opioids are recommended for the symptomatic treatment of persistent breathlessness, with morphine most extensively studied for this indication. It is extensively metabolized in the liver into water-soluble 3- and 6-glucuronides, excreted by the kidneys. In the case of advanced renal failure, the glucuronides accumulate, mainly responsible for toxicity 3-glucuronides. Some people, predominantly those with advanced renal failure, develop neurotoxic effects after chronic morphine, even when prescribed at a very low dose. A single-center case series of consecutive patients experiencing neurotoxic effects after long-term, low-dose morphine or at risk of such effects were transferred to methadone to avoid the accumulation of neurotoxic metabolites. Over the course of 4.5 years, 26 patients have been treated with methadone in the median dose of 3.0 mg/24 h p.o., for persisting breathlessness. Sixteen of them had been treated previously with an opioid (usually morphine) at the median dose of 7.0 mg/24 h (morphine oral daily dose equivalent). They were transferred to methadone, with the median dose of 3.0 mg/24 h orally (methadone oral daily dose equivalent), and the median morphine-to-methadone dose ratio was 2.5:1. All patients experienced a meaningful improvement in breathlessness intensity after methadone, by a median of 5 points (range 1-8) on the 0-10 numerical rating scale (NRS) in the whole group, and by 2 points (range 0-8) in those pretreated with other opioids, mainly morphine. Low-dose methadone can be considered an efficient alternative to morphine for reducing breathlessness in people experiencing neurotoxic effects or at risk of developing them following treatment with morphine.

Comparison of neonatal outcomes in pregnant women undergoing medication-assisted treatment of opioid use disorder with methadone or buprenorphine/naloxone

INTRODUCTION

The number of pregnant women with opioid use disorder (OUD) has quadrupled from 1999 to 2014. Current first line treatment for OUD in pregnancy is methadone with increasing support for buprenorphine. Limited data exist on use of buprenorphine/naloxone for OUD in pregnancy despite it being standard therapy in the non-pregnant individuals. The aim of this study was to compare neonatal opioid withdrawal syndrome (NOWS) prevalence and characteristics among neonates born to women prescribed methadone and buprenorphine/naloxone.

METHODS

This is a retrospective cohort analysis of mother-neonate dyads treated with either methadone or buprenorphine/naloxone for OUD in pregnancy who received prenatal care in the substance abuse, treatment, education, and prevention program (STEPP) clinic and delivered at OSU. Primary neonatal outcomes included: neonates diagnosed and treated for NOWS, peak scores on Modified Finnegan Neonatal Abstinence Score (FNAS), number of scores ≥9 on FNAS, and duration of treatment for NOWS. Secondary outcomes included: fetal growth restriction, preterm birth (<37 weeks), neonatal head circumference, birth weight, NICU admission, five-minute Apgar score, and length of hospitalization.

RESULTS

From 2013 to 2017, we identified 588 mother-neonate dyads: 149 treated with methadone and 439 treated with buprenorphine/naloxone. Ninety-eight neonates (65.8%) in the methadone group were diagnosed with NOWS requiring pharmacological interventions compared with 170 (38.7%) in the buprenorphine/naloxone group (aOR 3.46, 95% confidence interval (CI) 2.31-5.20, p < .01). Methadone-exposed neonates were six times more likely to be treated with >1 medication for NOWS (aOR 6.32, 95% CI 2.20-18.13, p < .01). Fetal growth restriction was diagnosed more often in the methadone group compared to the buprenorphine/naloxone group (aOR 1.73, 95% CI 1.02-2.93, p < .01). Significant maternal findings were that women using methadone for OUD started PNC earlier (15w vs. 17w, p = .04) and were less likely to be taking selective serotonin-reuptake inhibitors (SSRIs) (15% vs. 25%, p = .02) compared to the buprenorphine/naloxone group.

CONCLUSIONS

Buprenorphine/naloxone treatment for OUD in pregnancy appears safe and has decreased NOWS and pharmacologic intervention for the neonate.

Commentary on Burns et al: MOUD saves lives, especially after 60 days, and the longer the better

Scaling interventions and treatment services to reduce mortality stemming from OUD is critical for turning back the opioid epidemic, yet empiric data are lacking regarding how risk changes over the course of care. Burns et al show substantial reductions in hazards of overdose accrue after 60 continuous days on medication.

GC-MS Analysis of Methadone and EDDP in Addicted Patients under Methadone Substitution Treatment: Comparison of Urine and Plasma as Biological Samples

(1) Background: Methadone, along with buprenorphine, is the most commonly used drug for the treatment of opioid dependence. This study aimed to analyze methadone and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenyl pyrrolidine (EDDP), in the urine and plasma of opiate addicts. The study group consisted of drug users voluntarily admitted to the detoxification center C.E.T.T.T. "St. Stelian" of Bucharest. Secondly, the study aimed to identify whether urine or plasma provides better results for the proposed method. (2) Methods: A GC-MS method, using an internal standard (diphenylamine) in the FULL-SCAN and SIM modes of operation and using the m/z = 72 ion for methadone and the m/z = 277 ion for EDDP, combined with a liquid-liquid extraction procedure was performed. (3) Results: The applied procedure allows the detection and quantification of methadone in both urine and plasma samples. EDDP was identified in patients with higher levels of methadone. Higher levels of methadone were detected in urine than in plasma samples. (4) Conclusions: This procedure can be used in clinical laboratories for the rapid determination of methadone levels in urine rather than in plasma. The procedure can be applied for the monitoring of methadone substitution treatment.

Methadone alters the peripheral inflammatory and central immune landscape following prenatal exposure in rats

Opioid use during pregnancy continues to rise at alarming rates with a parallel trend in the number of infants and children exposed to opioid medications each year. Prenatal opioid exposure (POE) occurs at a critical timepoint in neurodevelopment disrupting intricate pathways essential for neural-immune maturation with the potential for devastating long-term consequences. Understanding the mechanisms underlying injury associated with POE is essential to address long-term outcomes and identify diagnostic and therapeutic biomarkers in this vulnerable patient population. Using an established preclinical model of POE, we investigated changes in cerebral and peripheral inflammation and peripheral blood mononuclear cell (PBMC) activity. We hypothesized that neuroinflammation, as defined by changes in specific cerebral immune cell populations, would exist in adult rats following POE concomitant with sustained peripheral immune hyperreactivity (SPIHR). Our data demonstrated alterations in cerebral immune cells at postnatal day 60 (P60) typified by increased regulatory T cells (p < 0.01) and neutrophils (p < 0.05) in rats with POE compared to controls. Evaluation of serum revealed increased levels of IL-6 (p < 0.05) and CXCL1 (p < 0.05) at P21 in rats with POE compared to controls with no significant difference in cytokine or chemokine levels between the two groups at P60. Additionally, PBMCs isolated from rats with POE at P21 demonstrated baseline hypersecretion of IL-6 (p < 0.01) and SPIHR with increased levels of TNF-α (p < 0.05) and CXCL1 (p < 0.05) following stimulation with LPS. At P60, however, there was no significant difference found in cytokine or chemokine levels secreted by PBMCs isolated from rats with POE at baseline or with LPS stimulation when compared to controls. Taken together, these data demonstrate cerebral inflammation months after prenatal opioid exposure and long after the resolution of systemic inflammation and SPIHR seen at toddler age equivalent. Chronic alterations in the cerebral immune cell populations secondary to prenatal opioid exposure may underly long-term consequences of developmental brain injury including deficits in cognition and attention. These findings may be invaluable to further investigations of precise biomarkers of injury and targeted therapeutics for this vulnerable population.

"Knock Me Out": The Challenges of Managing Pain Due to Cutaneous T Cell Lymphomas: A Case Report

Cutaneous T cell lymphomas are associated with distressing symptoms, including pain and pruritus that negatively impact quality of life. Early involvement of palliative care can provide relief of symptoms and address multifaceted distress. This case highlights the complex management of cutaneous T cell lymphoma pain and associated symptoms, including existential and psychosocial distress. Our patient required frequent titration and rotation of high-dose opioids and adjuvant analgesics, ultimately requiring transfer to the intensive care unit for analgosedation. Total skin loss and disease complications led to his death after a compassionate withdrawal of life support. Cutaneous T cell lymphoma pain can be successfully managed with an interdisciplinary approach, early palliative care, and aggressive pain management. Complications from advanced disease, superinfection, and multidimensional distress complicate the efficacy of a multimodal analgesic approach. Further research is needed to deepen our understanding of how to optimally alleviate suffering within this vulnerable population.

Methadone pharmacogenetics in vitro and in vivo: Metabolism by CYP2B6 polymorphic variants and genetic variability in paediatric disposition

AIMS

Methadone metabolism and clearance are determined principally by polymorphic cytochrome P4502B6 (CYP2B6). Some CYP2B6 allelic variants affect methadone metabolism in vitro and disposition in vivo. We assessed methadone metabolism by CYP2B6 minor variants in vitro. We also assessed the influence of CYP2B6 variants, and P450 oxidoreductase (POR) and CYP2C19 variants, on methadone clearance in surgical patients in vivo.

METHODS

CYP2B6 and P450 oxidoreductase variants were coexpressed with cytochrome b5 . The metabolism of methadone racemate and enantiomers was measured at therapeutic concentrations and intrinsic clearances were determined. Adolescents receiving methadone for surgery were genotyped for CYP2B6, CYP2C19 and POR, and methadone clearance and metabolite formation clearance were determined.

RESULTS

In vitro, CYP2B6.4 was more active than wild-type CYP2B6.1. CYPs 2B6.5, 2B6.6, 2B6.7, 2B6.9, 2B6.17, 2B6.19 and 2B6.26 were less active. CYPs 2B6.16 and 2B6.18 were inactive. CYP2B6.1 expressed with POR variants POR.28, POR.5 and P228L had lower rates of methadone metabolism than wild-type reductase. In vivo, methadone clinical clearance decreased linearly with the number of CYP2B6 slow metabolizer alleles, but was not different in CYP2C19 slow or rapid metabolizer phenotypes, or in carriers of the POR*28 allele.

CONCLUSIONS

Several CYP2B6 and POR variants were slow metabolizers of methadone in vitro. Polymorphisms in CYP2B6, but not CYP2C19 or P450 reductase, affected methadone clearance in vivo. CYP2B6 polymorphisms 516G>T and 983T>C code for canonical loss of function variants and should be assessed when considering genetic influences on clinical methadone disposition. These complementary translational in vitro and in vivo results inform on pharmacogenetic variability affecting methadone disposition in patients.

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.

Scheduled methadone reduces overall opioid requirements after pediatric posterior spinal fusion: A single center retrospective case series

BACKGROUND

Posterior spinal fusion to correct adolescent idiopathic scoliosis is associated with significant postoperative pain. Different modalities have been reported as part of a multimodal analgesic plan. Intravenous methadone acts as a mu-opioid agonist and N-Methyl-D-aspartate (NMDA) antagonist and has been shown to have opioid-sparing effects. Our multimodal approach has included hydromorphone patient-controlled analgesia (PCA) with and without preincisional methadone, and recently postoperative methadone without a PCA.

AIMS

We hypothesized that a protocol including scheduled postoperative methadone doses would reduce opioid usage compared to PCA-based strategy.

METHODS

A retrospective chart review of patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis between 2015 and 2020 was performed. There were three patient groups: Group PCA received a hydromorphone PCA without methadone; Group PCA + Methadone received preincisional methadone and a hydromorphone PCA; Group Methadone received preincisional methadone, scheduled postoperative methadone, and no PCA. The primary outcome was postoperative opioid use over 72 h. Secondary outcomes included pain scores, sedation scores, and length of stay.

RESULTS

Group PCA (n = 26) consumed 0.33 mg/kg (95% CI [0.28, 0.38]) total hydromorphone equivalents, Group PCA + methadone (n = 39) 0.30 mg/kg (95% CI [0.25, 0.36]) total hydromorphone equivalents, and Group methadone (n = 22) 0.18 mg/kg (95% CI [0.15, 0.21]) total hydromorphone equivalents (p = .00096). There were no statistically significant differences between the groups for secondary outcomes.

CONCLUSION

A protocol with intraoperative and scheduled postoperative methadone doses resulted in a 45% reduction in opioid usage compared to a PCA-based protocol with similar analgesia after pediatric posterior spinal fusion.

Impact of fentanyl use on initiation and discontinuation of methadone and buprenorphine/naloxone among people with prescription-type opioid use disorder: secondary analysis of a Canadian treatment trial

BACKGROUND AND AIMS

Fentanyl is primarily responsible for the current phase of the overdose epidemic in North America. Despite the benefits of treatment with medications for opioid use disorder (MOUD), there are limited data on the association between fentanyl, MOUD type and treatment engagement. The objectives of this analysis were to measure the impact of baseline fentanyl exposure on initiation and discontinuation of MOUD among individuals with prescription-type opioid use disorder (POUD).

DESIGN, SETTING AND PARTICIPANTS

Secondary analysis of a Canadian multi-site randomized pragmatic trial conducted between 2017 and 2020. Of the 269 randomized participants, 65.4% were male, 67.3% self-identified as white and 55.4% had a positive fentanyl urine drug test (UDT) at baseline. Fentanyl-exposed participants were more likely to be younger, to self-identify as non-white, to be unemployed or homeless and to be currently using stimulants than non-fentanyl-exposed participants.

INTERVENTIONS

Flexible take-home dosing buprenorphine/naloxone or supervised methadone models of care for 24 weeks.

MEASUREMENTS

Outcomes were (1) MOUD initiation and (2) time to (a) assigned and (b) overall MOUD discontinuation. Independent variables were baseline fentanyl UDT (predictor) and assigned MOUD (effect modifier).

FINDINGS

Overall, 209 participants (77.7%) initiated MOUD. In unadjusted analyses, fentanyl exposure was associated with reduced likelihood of treatment initiation [odds ratio (OR) = 0.18, 95% confidence interval (CI) = 0.08-0.36] and shorter median times in assigned [20 versus 168 days, hazard ratio (HR) = 3.61, 95% CI = 2.52-5.17] and any MOUD (27 versus 168 days, HR = 3.32, 95% CI = 2.30-4.80). The negative effects were no longer statistically significant in adjusted models, and no interaction between fentanyl and MOUD was observed for any of the outcomes (all P > 0.05).

CONCLUSIONS

Both buprenorphine/naloxone and methadone may be appropriate treatment options for people with prescription-type opioid use disorder regardless of fentanyl exposure. Other characteristics of fentanyl-exposed individuals appear to be driving the association with poorer treatment outcomes.

Intraoperative Methadone and Short Stay Spine Surgery: Possible Barriers to Implementation and Future Opportunities

The frequency of shorter stay spine surgery is increasing. Acute pain is a common barrier to discharge following spine surgery. Long-acting opioid medications like methadone have the potential to provide sustained analgesia when given intraoperatively. Methadone has been effectively used in complex spine surgery, cardiac surgery, and more recently applied to ambulatory procedures. In this article, we summarize the pertinent available literature on the use of intraoperative methadone for spine surgery as well as the recent data on intraoperative methadone for ambulatory surgery. The aim of this perspectives article is to describe the potential opportunities for applying intraoperative methadone to shorter stay spine surgery as well as barriers to more widespread use. While there are currently no trials that have specifically studied methadone for shorter stay spine surgery specifically to date, it is a promising area for future research.

Management of opioid use disorder, opioid withdrawal, and opioid overdose prevention in hospitalized adults: A systematic review of existing guidelines

BACKGROUND

Hospitalizations related to the consequences of opioid use are rising. National guidelines directing in-hospital opioid use disorder (OUD) management do not exist. OUD treatment guidelines intended for other treatment settings could inform in-hospital OUD management.

OBJECTIVE

Evaluate the quality and content of existing guidelines for OUD treatment and management.

DATA SOURCES

OVID MEDLINE, PubMed, Ovid PsychINFO, EBSCOhost CINHAL, ERCI Guidelines Trust, websites of relevant societies and advocacy organizations, and selected international search engines.

STUDY SELECTION

Guidelines published between January 2010 to June 2020 addressing OUD treatment, opioid withdrawal management, opioid overdose prevention, and care transitions among adults.

DATA EXTRACTION

We assessed quality using the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument.

DATA SYNTHESIS

Nineteen guidelines met the selection criteria. Most recommendations were based on observational studies or expert consensus. Guidelines recommended the use of nonstigmatizing language among patients with OUD; to assess patients with unhealthy opioid use for OUD using the Diagnostic Statistical Manual of Diseases-5th Edition criteria; use of methadone or buprenorphine to treat OUD and opioid withdrawal; use of multimodal, nonopioid therapy, and when needed, short-acting opioid analgesics in addition to buprenorphine or methadone, for acute pain management; ensuring linkage to ongoing methadone or buprenorphine treatment; referring patients to psychosocial treatment; and ensuring access to naloxone for opioid overdose reversal.

CONCLUSIONS

Included guidelines were informed by studies with various levels of rigor and quality. Future research should systematically study buprenorphine and methadone initiation and titration among people using fentanyl and people with pain, especially during hospitalization.

Management of opioid use disorder and associated conditions among hospitalized adults: A Consensus Statement from the Society of Hospital Medicine

Hospital-based clinicians frequently care for patients with opioid withdrawal or opioid use disorder (OUD) and are well-positioned to identify and initiate treatment for these patients. With rising numbers of hospitalizations related to opioid use and opioid-related overdose, the Society of Hospital Medicine convened a working group to develop a Consensus Statement on the management of OUD and associated conditions among hospitalized adults. The guidance statement is intended for clinicians practicing medicine in the inpatient setting (e.g., hospitalists, primary care physicians, family physicians, advanced practice nurses, and physician assistants) and is intended to apply to hospitalized adults at risk for, or diagnosed with, OUD. To develop the Consensus Statement, the working group conducted a systematic review of relevant guidelines and composed a draft statement based on extracted recommendations. Next, the working group obtained feedback on the draft statement from external experts in addiction medicine, SHM members, professional societies, harm reduction organizations and advocacy groups, and peer reviewers. The iterative development process resulted in a final Consensus Statement consisting of 18 recommendations covering the following topics: (1) identification and treatment of OUD and opioid withdrawal, (2) perioperative and acute pain management in patients with OUD, and (3) methods to optimize care transitions at hospital discharge for patients with OUD. Most recommendations in the Consensus Statement were derived from guidelines based on observational studies and expert consensus. Due to the lack of rigorous evidence supporting key aspects of OUD-related care, the working group identified important issues necessitating future research and exploration.

Opioid agonist treatment improves progression through the HIV cascade of care among people living with HIV who use unregulated opioids

OBJECTIVES

Opioid agonist treatment (OAT) has been shown to improve certain HIV-related treatment measures among people with HIV (PHIV) with opioid use disorder (OUD). However, there is limited data on the impacts of OAT along the whole HIV cascade of care.

DESIGN AND METHODS

Using data from an ongoing cohort of PHIV who use drugs in Vancouver, Canada, we used cumulative link mixed-effects models to estimate the independent effect of OAT on achieving progressive steps in the HIV cascade among participants using unregulated opioids daily, after adjusting for confounders.

RESULTS

Between 2005 and 2017, we recruited 639 PHIV regularly using opioids (median age 42 years, 59% male, 56% White), of whom 70% were on OAT at their baseline visit. Engagement in OAT showed a nonsignificant trend with higher linkage to HIV care (adjusted partial proportional odds ratio [APPO] = 1.75, 95% confidence interval [CI]: 0.83-3.69), and significantly higher cumulative odds of successfully achieving subsequent HIV cascade steps: on ART (APPO = 3.85, 95% CI: 2.33-6.37); adherent to ART (APPO = 3.15, 95% CI: 2.15-4.62); and HIV viral suppression (APPO = 2.18, 95% CI: 1.51-3.14).

CONCLUSIONS

This study found a high level of OAT engagement among PHIV using unregulated opioids and that OAT engagement resulted in significantly increased progression through some of the higher steps of the HIV cascade. While these findings are encouraging, they highlight the need to reach populations off OAT to maximize the clinical and community-level benefits of ART.

Opioid Use Disorder Treatment Initiation and Continuation: a Qualitative Study of Patients Who Received Addiction Consultation and Hospital-Based Providers

BACKGROUND

Hospitalizations related to opioid use disorder (OUD) are rising. Addiction consultation services (ACS) increasingly provide OUD treatment to hospitalized patients, but barriers to initiating and continuing medications for OUD remain. We examined facilitators and barriers to hospital-based OUD treatment initiation and continuation from the perspective of patients and healthcare workers in the context of an ACS.

METHODS

In this qualitative study, we sought input using key informant interviews and focus groups from patients who received care from an ACS during their hospitalization and from hospitalists, pharmacists, social workers, and nurses who work in the hospital setting. A multidisciplinary team coded and analyzed transcripts using a directed content analysis.

FINDINGS

We conducted 20 key informant interviews with patients, nine of whom were interviewed following hospital discharge and 12 of whom were interviewed during a rehospitalization. We completed six focus groups and eight key informant interviews with hospitalists and hospital-based medical staff (n = 62). Emergent themes related to hospital-based OUD treatment included the following: the benefit of an ACS to facilitate OUD treatment engagement; expanded use of methadone or buprenorphine to treat opioid withdrawal; the triad of hospitalization, self-efficacy, and easily accessible, patient-centered treatment motivates change in opioid use; adequate pain control and stabilization of mental health conditions among patients with OUD contributed to opioid agonist therapy (OAT) continuation; and stable housing and social support are prerequisites for OAT uptake and continuation.

CONCLUSION

Modifiable factors which facilitate hospital-based OUD treatment initiation and continuation include availability of in-hospital addiction expertise to offer easily accessible, patient-centered treatment and the use of methadone or buprenorphine to manage opioid withdrawal. Further research and public policy efforts are urgently needed to address reported barriers to hospital-based OUD treatment initiation and continuation which include unstable housing, poorly controlled chronic medical and mental illness, and lack of social support.

Management of opioid withdrawal and initiation of medications for opioid use disorder in the hospital setting

Opioid use disorder (OUD) has become increasingly prevalent among hospitalized patients in the United States and globally. As its prevalence increases, this provides a valuable opportunity for clinicians in the hospital setting to engage and initiate management and treatment of OUD. This article aims to provide hospitalists and other clinicians working in the hospital with a narrative review of the management of opioid withdrawal and the initiation of medications for opioid use disorder (MOUD) in the hospital and provide an update on a novel low dose approach to buprenorphine induction (also commonly referred to as the "microinduction" method). Management can initially include treating withdrawal symptoms with opioids as well as with a combination of non-opioid medications such as alpha 2 agonists, benzodiazepines, and/or antiemetics as needed. Besides simply managing withdrawal symptoms, clinicians can further improve the care of patients with OUD through initiating maintenance treatment with MOUD, ideally with opioids used in the initial management of withdrawal. Opioid detoxification is an inferior method of primary treatment and is associated with relapse and poor outcomes. In contrast, treatment with MOUD using methadone or buprenorphine is associated with superior treatment outcomes and reduced relapse compared to detoxification alone. Treatment with MOUD using methadone or buprenorphine can be successfully used in the hospital setting. A novel low dose approach to buprenorphine induction may be useful in minimizing precipitated withdrawals in patients who have recently used or received opioids, which makes this an attractive option in the hospital where patients are frequently on opioids for acutely painful conditions. The hospital setting also provides a valuable opportunity for clinicians to address harm reduction in patients with OUD. Finally, clinicians can improve the long-term outcomes of patients with OUD by ensuring a smooth discharge with adequate and timely follow-up.

Laws for expanding access to medications for opioid use disorder: a legal analysis of 16 states & Washington D.C

Background: Medications for opioid use disorder (MOUDs) are the gold standard for OUD treatment but are underused. To our knowledge, no published study has systematically identified and categorized state policy innovations for expanding MOUD utilization.Objective: We sought to identify and categorize state MOUD policy innovations.Methods: Within a stratified random sample of 16 U.S. states and Washington D.C. we searched for 2019 state statutes and regulations related to MOUD in Westlaw legal database. We then identified laws that appeared designed to increase MOUD utilization and categorized them using a template analysis approach.Results: We found 82 laws with one or more MOUD expansion policies. We identified six high-level MOUD expansion policy categories: 1) policies expanding the availability of waivered buprenorphine providers; 2) needs assessments and policies increasing public MOUD awareness; 3) criminal justice system policies; 4) Substance use disorder (SUD) treatment and sober living facility policies; 5) insurance policies; and 6) hospital policies. SUD treatment and housing facility policies, as well as insurance policies, were most common.Conclusions: Multipronged approaches are being pursued by several states to increase MOUD access. Our results can inform policymakers of MOUD expansion approaches in other jurisdictions. Policy categories can serve as the basis for policy variables for future analyses of policy effects.

HIV clinic-based extended-release naltrexone versus treatment as usual for people with HIV and opioid use disorder: a non-blinded, randomized non-inferiority trial

BACKGROUND AND AIM

Opioid agonist medications for treatment of opioid use disorder (OUD) can improve human immunodeficiency virus (HIV) outcomes and reduce opioid use. We tested whether outpatient antagonist treatment with naltrexone could achieve similar results.

DESIGN

Open-label, non-inferiority randomized trial.

SETTING

Six US HIV primary care clinics.

PARTICIPANTS

A total of 114 participants with untreated HIV and OUD (62% male; 56% black, 12% Hispanic; positive for fentanyl (62%), other opioids (47%) and cocaine (60%) at baseline). Enrollment halted early due to slow recruitment.

INTERVENTION

HIV clinic-based extended-release naltrexone (XR-NTX; n = 55) versus treatment as usual (TAU) with buprenorphine or methadone (TAU; n = 59).

MEASUREMENTS

Treatment group differences were compared for the primary outcome of viral suppression (HIV RNA ≤ 200 copies/ml) at 24 weeks and secondary outcomes included past 30-day use of opioids at 24 weeks.

FINDINGS

Fewer XR-NTX participants initiated medication compared with TAU participants (47 versus 73%). The primary outcome of viral suppression was comparable for XR-NTX (52.7%) and TAU (49.2%) [risk ratio (RR) = 1.064; 95% confidence interval (CI) = 0.748, 1.514] at 24 weeks. Non-inferiority could not be demonstrated, as the lower confidence limit of the RR did not exceed the pre-specified margin of 0.75 in intention-to-treat (ITT) analysis. The main secondary outcome of past 30-day opioid use was comparable for XR-NTX versus TAU (11.7 versus 14.8 days; mean difference = -3.1; 95% CI = -8.7, 1.1) in ITT analysis. Among those initiating medication, XR-NTX resulted in fewer days of opioid use compared with TAU in the past 30 days (6.0 versus 13.6, mean difference = -7.6; 95% CI = -13.8, -0.2).

CONCLUSIONS

A randomized controlled trial found supportive, but not conclusive, evidence that human immunodeficiency virus clinic-based extended-release naltrexone is not inferior to treatment as usual for facilitating human immunodeficiency virus viral suppression. Participants who initiated extended-release naltrexone used fewer opioids than those who received treatment as usual.

Sedation quality of alfaxalone associated with butorphanol, methadone or pethidine in cats injected into the supraspinatus or the quadriceps muscle

OBJECTIVES

The aim of this study was to compare the quality of sedation with three different anaesthetic protocols (alfaxalone combined with butorphanol, methadone or pethidine) administered intramuscularly in cats, and to evaluate the influence of the injection site (between supraspinatus and quadriceps muscles) on the onset and quality of sedation.

METHODS

A total of 151 cats were selected for this study. Cats were sedated with alfaxalone (3 mg/kg) combined with either butorphanol (0.3 mg/kg; n = 50), methadone (0.3 mg/kg; n = 53) or pethidine (5 mg/kg; n = 48). The combination was injected intramuscularly into the supraspinatus (n = 79) or quadriceps muscle (n = 72). The data included a scoring system for the quality of sedation and physiological parameters, such as heart rate (HR), respiratory rate, body temperature and occurrence of mydriasis, monitored during the first 30 mins of anaesthesia.

RESULTS

The opioid associated with alfaxalone influenced the overall sedation score, the degree of myorelaxation, the occurrence of mydriasis and HR. The overall sedation score was poorer with butorphanol than with methadone (P = 0.008), and butorphanol induced a lower degree of myorelaxation than methadone (P = 0.013). The injection into the supraspinatus showed better qualitative results for sedation and a faster onset time (in about 3 mins) than that into the quadriceps (P <0.001). HR decreased from baseline (P <0.001) and over time (P <0.001), mainly in cats of the butorphanol-supraspinatus and pethidine-quadriceps groups (P = 0.004). The occurrence of mydriasis was lower after butorphanol than after methadone and pethidine (P = 0.025), while the incidence of side effects did not differ among groups.

CONCLUSIONS AND RELEVANCE

All three protocols provided a good quality of sedation and allowed performing the scheduled procedure. Moreover, the injection into the supraspinatus muscle showed superior results in all the qualitative scores of sedation and quicker onset time than that into the quadriceps muscle.

"You're Not Supposed to be on it Forever": Medications to Treat Opioid Use Disorder (MOUD) Related Stigma Among Drug Treatment Providers and People who Use Opioids

Opioid use disorder (OUD) through prescription opioid misuse, heroin, and illicitly manufactured fentanyl use has increased dramatically in the past 20 years. Medications to treat opioid use disorder (MOUD) is considered the gold standard for treating opioid use disorders but uptake remains low. Recently, Madden has argued that in addition to the stigma assigned to substance use and people with SUD, MOUDs also are stigmatized, a process she labels intervention stigma to distinguish it from condition stigma (ie, stigma of SUD) . In this paper, we examine MOUD related stigma from the perspective of people who use opioids (PWUO) and key informants who play some role in providing or referring people to drug treatment. Providers and PWOU often viewed MOUD as one drug replacing another which discouraged providers from recommending and PWUO from accepting MOUD. MOUD stigma was also expressed by providers' exaggerated fear of MOUD diversion. The extent to which MOUD was accepted as a legitimate treatment varied and influenced treatment providers' perceptions of the goals of drug treatment and the length of time that MOUD should be used with many feeling that MOUD should only be used as a temporary tool while PWOU work on other treatment goals. This led to tapering off of MOUD after some time in treatment. Some providers also expressed mistrust of MOUD stemming from their previous experiences with the over-prescription of opioids for pain which led to the current crisis. Results from this study suggest that the proportion of PWUO on MOUD is unlikely to increase without addressing MOUD stigma among drug treatment providers and PWUO seeking treatment.

Factors associated with patient perceived suboptimal dosing of in-hospital opioid agonist therapy among people who use illicit drugs in Vancouver, Canada

Optimal dosing of opioid agonist therapy (OAT) is essential for treatment success. However, initiation and maintenance of OAT in hospital settings can be challenging given differing levels of opioid tolerance, withdrawal, and intoxication among patients.

The objective of this study was to characterize the prevalence and factors associated with in-hospital patient perceived suboptimal OAT dosing among people who use illicit drugs (PWUD) in Vancouver, Canada.

Data were derived from three prospective cohorts of PWUD in Vancouver, Canada. Bivariable and multivariable logistic regression models were used to examine factors associated with patient perceived suboptimal in-hospital OAT dose.

273 study participants were prescribed OAT while in hospital: 83 (30.4%) participants perceived their OAT dose to be suboptimal. In a multivariable model, factors positively associated with a perceived suboptimal OAT dose included: homelessness (adjusted odds ratio [AOR] = 2.85; 95% CI: 1.53-5.28), daily stimulant use (AOR = 2.03; 95% CI: 1.14-3.63) and illicit drug use while in hospital (AOR = 2.33; 95% CI: 1.31-4.16).

Almost one third of participants perceived receiving a suboptimal OAT dose while in hospital. These observed correlations indicate that a patient's perception of suboptimal OAT dosing in hospital may be more prevalent for patients who are homeless, report polysubstance use with stimulants and opioids and who obtain illicit drugs while hospitalized. While cautious prescribing of OAT in patients experiencing hospitalization is important, these findings demonstrate a high prevalence of and apparent risk factors for perceived suboptimal OAT dosing.

Differences in the delivery of medications for opioid use disorder during hospitalization by racial categories: A retrospective cohort analysis

Background: As the drug-related overdose crisis and COVID-19 pandemic continue, communities need increased access to medications for opioid use disorder (MOUD) (i.e., buprenorphine and methadone). Disparities in the type of MOUD prescribed or administered by racial and ethnic categories are well described in the outpatient clinical environment. It is unknown, however, if these disparities persist when MOUD is provided in acute care hospitals. Methods: This study assessed differences in the delivery of buprenorphine versus methadone during acute medical or surgical hospitalizations for veterans with opioid use disorder (OUD) by racial categories (Black Non-Hispanic or Latino vs. White Non-Hispanic or Latino). Data were obtained retrospectively from the Veterans Health Administration (VHA) for federal fiscal year 2017. We built logistic regression models, adjusted for individual and hospital-related covariates, and calculated the predicted probabilities of MOUD delivery by racial categories. Results: The study cohort (n = 1,313 unique patients; N = 107 VHA hospitals) had a mean age of 57 (range 23 to 87 years), was predominantly male (96%), and composed entirely of Black (29%) or White (71%) patients. White patients were 11% more likely than Black patients to receive buprenorphine than methadone during hospitalization (p = 0.010; 95% CI: 2.7%, 20.0%). Among patients on MOUD prior to hospitalization, White patients were 21% more likely than Black patients to receive buprenorphine (p = 0.000; 95% CI: 9.8%, 31.5%). Among patients newly initiated on MOUD during hospitalization, there were no differences by racial categories. Conclusion: We observed disparities in the delivery of buprenorphine versus methadone during hospitalization by racial categories. The observed differences in hospital-based MOUD delivery may be influenced by MOUD received prior to hospitalization within the racialized outpatient addiction treatment system. The VHA and health systems more broadly must address all aspects of racism that contribute to inequitable MOUD access throughout all clinical contexts.

Methadone Blockade of Cardiac Inward Rectifier K+ Current Augments Membrane Instability and Amplifies U Waves on Surface ECGs: A Translational Study

Background Methadone is associated with a disproportionate risk of sudden death and ventricular tachyarrhythmia despite only modest inhibition of delayed rectifier K⁺ current (I_Kr)_, the principal mechanism of drug-associated arrhythmia. Congenital defects of inward rectifier K⁺ current (I_K1) have been linked to increased U-wave amplitude on ECG and fatal arrhythmia. We hypothesized that methadone may also be a potent inhibitor of I_K1, contributing to delayed repolarization and manifesting on surface ECGs as augmented U-wave integrals. Methods and Results Using a whole-cell voltage clamp, methadone inhibited both recombinant and native I_K1 with a half-maximal inhibitory concentration IC50) of 1.5 μmol/L, similar to that observed for I_Kr block (half-maximal inhibitory concentration of 2.9 μmol/L). Methadone modestly increased the action potential duration at 90% repolarization and slowed terminal repolarization at low concentrations. At higher concentrations, action potential duration at 90% repolarization lengthening was abolished, but its effect on terminal repolarization rose steadily and correlated with increased fluctuations of diastolic membrane potential. In parallel, patient ECGs were analyzed before and after methadone initiation, with 68% of patients having a markedly increased U-wave integral compared with premethadone (lead V3; mean +38%±15%, P=0.016), along with increased QT and T_Peak to T_End intervals, likely reflective of I_Kr block. Conclusions Methadone is a potent I_K1 inhibitor that causes augmentation of U waves on surface ECG. We propose that increased membrane instability resulting from I_K1 block may better explain methadone's arrhythmia risk beyond I_Kr inhibition alone. Drug-induced augmentation of U waves may represent evidence of blockade of multiple repolarizing ion channels, and evaluation of the effect of that agent on I_K1 may be warranted.

Real-world effectiveness of pharmacological treatments of opioid use disorder in a national cohort

AIM

To investigate the real-world effectiveness of pharmacological treatments (buprenorphine, methadone) of opioid use disorder (OUD).

DESIGN

A nation-wide, register-based cohort study.

SETTING

Sweden.

PARTICIPANTS

All residents aged 16-64 years living in Sweden using OUD medication from July 2005 to December 2016 (n = 5757, 71.8% men) were identified from registers of prescriptions, inpatient and specialized outpatient care, causes of death, sickness absence and disability pensions.

MEASUREMENTS

Main outcome: hospitalization due to OUD.

SECONDARY OUTCOMES

hospitalization due to any cause; death due to all, natural and external causes. Mortality was analyzed with between-individual multivariate-adjusted Cox hazards regression model. Recurrent outcomes, such as hospitalizations, were analyzed with within-individual analyses to eliminate selection bias. OUD medication use versus non-use was modelled with PRE2DUP (from prescription drug purchases to drug use periods) method.

FINDINGS

Buprenorphine [hazard ratio (HR) = 0.73, 95% confidence interval (CI) = 0.54-0.97] and methadone (HR = 0.74, 95% CI = 0.59-0.93) use were associated with significantly lower risk of OUD hospitalization, but not any-cause hospitalizations, compared with the time-periods when the same individual did not use OUD medication. The use of buprenorphine and methadone were both associated with significantly lower risk of all-cause mortality (HR = 0.45, 95% CI = 0.34-0.59; HR = 0.51, 95% CI = 0.41-0.63, respectively), compared with non-use of both medications. Similar results were found for risk of mortality due to external causes (HR = 0.39; 95% CI = 0.27-0.54; HR = 0.40; 95% CI = 0.29-0.53, respectively), but not for mortality due to natural causes. The risk of OUD hospitalization and all-cause mortality was decreased in all duration categories of studied medications (< 30, 31-180, 181-365 and >365 days), except for methadone use less than 30 days.

CONCLUSIONS

The use of buprenorphine and methadone are both associated with a significantly lower risk of hospitalization due to opioid use disorder and death due to all and external causes, when compared with non-use.

Perinatal methadone exposure attenuates myelination and induces oligodendrocyte apoptosis in neonatal rat brain

Methadone (MTD) is a commonly prescribed treatment for opioid use disorder in pregnancy, despite limited information on the effects of passive exposure on fetal brain development. Animal studies suggest a link between perinatal MTD exposure and impaired white matter development. In this study, we characterized the effect of perinatal MTD exposure through the evaluation of oligodendrocyte development and glial cell activation in the neonatal rat brain. Six pregnant Sprague Dawley rat dams were randomized to MTD (0.2 mL/L) or untreated drinking water from embryonic day 7. Pups were terminated at postnatal day 7 and tissue sections were harvested from six randomly selected pups (one male and one female per litter) of each experimental group for immunohistochemistry in areas of corpus callosum (CC), lateral CC, external capsule (EC), and cerebellar white matter. In the MTD-exposed rat pups, myelination was significantly decreased in the CC, lateral CC, EC, and arbor vitae compared with the controls. The increased density and percentage of oligodendrocyte precursor cells (OPCs) were observed in the CC and cerebellar white matter. The highly active proliferation of OPCs as well as decreased density and percentage of differentiated oligodendrocytes were found in the cerebellum but no differences in the cerebrum. Apoptotic activities of both differentiated oligodendrocytes and myelinating oligodendrocytes were significantly increased in all regions of the cerebrum and cerebellum after MTD exposure. There was no quantitative difference in astrocyte, however, cell density and/or morphologic difference consistent with activation were observed in microglia throughout MTD-exposed CC and cerebellum. Taken together, perinatal MTD exposure reveals global attenuation of myelination, accelerated apoptosis of both differentiated and myelinating oligodendrocytes, and microglia activation, supporting an association between antenatal MTD exposure and impaired myelination in the developing brain.

Association of a Common NOS1AP Variant with Attenuation of QTc Prolongation in Men with Heroin Dependence Undergoing Methadone Treatment

Background: The effects of methadone-induced severe prolongation of the corrected QT interval (QTc) and sudden cardiac death appear unpredictable and sex-dependent. Genetic polymorphisms in the nitric oxide synthase 1 adaptor protein (NOS1AP) have been implicated in QTc prolongation in general populations. We investigated whether common NOS1AP variants interact with methadone in relation to QTc prolongation in patients with heroin dependence. Methods: We genotyped 17 NOS1AP variants spanning the entire gene in heroin-dependent patients who received a 12-lead electrocardiography (ECG) examination both at baseline and during maintenance methadone treatment in Cohort 1 and only during maintenance methadone treatment in Cohort 2. The QT interval was measured automatically by the Marquette 12SL program, and was corrected for heart rate using Bazett’s formula. Results: Cohort 1 consisted of 122 patients (age: 37.65 ± 8.05 years, 84% male, methadone dosage: 42.54 ± 22.17 mg/day), and Cohort 2 comprised of 319 patients (age: 36.9 ± 7.86 years, 82% male, methadone dosage: 26.08 ± 15.84 mg/day), with complete genotyping data for analyses. Before methadone, the QTc intervals increased with increasing age (r = 0.3541, p < 0.001); the age-adjusted QTc showed dose-dependent prolongation in men (r = 0.6320, p < 0.001), but abbreviation in women (r = −0.5348, p = 0.018) in Cohort 1. The pooled genotype-specific analysis of the two cohorts revealed that the QTc interval was significantly shorter in male carriers of the rs164148 AA variant than in male carriers of the reference GG genotype (GG: n = 262, QTc = 423 ± 1.4 ms; AA: n = 10, QTc = 404.1 ± 7 ms, p = 0.009), according to univariate analysis. The QTc remained shorter in male carriers of the rs164148 AA variant compared to GG genotype (423 ± 1.4 ms vs. 405.9 ± 6.9 ms, p = 0.016) in multivariate analysis after adjusting for age and methadone dosage. A cut-off QTc interval of <410 ms identifies 100% of AA carriers compared to none of GG carriers when receiving a daily methadone dosage of 30.6 ± 19.3 mg. There was no significant gene-drug interaction in contributing to the adjusted QTc (p = 0.2164) in male carriers of the rs164148 variants. Conclusions: Carriers of a common NOS1AP rs164148 AA genotype variant were associated with a shorter QTc interval in men receiving maintenance methadone treatment. This genetic polymorphism attenuates the QTc-prolonging effect by methadone, and thus may explain at least in part the unpredictable and heterogeneous risks for severe QTc prolongation and sudden cardiac death in patients on methadone.

Erythroxylum cuneatum prevented cellular adaptation in morphine-induced neuroblastoma cells

BACKGROUND

Chronic morphine stimulates prolonged stimulation of opioid receptors, especially µ-opioid subtype (MOR), which in turn signals cellular adaptation. However, the sudden termination of morphine after chronic intake causes withdrawal syndrome.

OBJECTIVES

Hence, this study was designed to find an alternative treatment for the morphine withdrawal using the alkaloid leaf extract of Erythroxylum cuneatum (E. cuneatum), done on morphine-exposed neuroblastoma cell lines.

METHODS

SK-N-SH, a commercialised neuroblastoma cell line, was used in two separate study designs; the antagonistic and pre-treatment of morphine. The antagonistic treatment was conducted through concurrent exposure of the cells to morphine and E. cuneatum or morphine and methadone for 24 h. The pre-treatment design was carried out by exposing the cells to morphine for 24 h, followed by 24 h exposures to E. cuneatum or methadone. The cytosolic fraction was collected and run for protein expression involved in cellular adaptation; mitogen-activated protein (MAP)/extracellular signal-regulated (ERK) kinase 1/2 (MEK 1/2), extracellular signal-regulated kinase 2 (ERK 2), cAMP-dependent protein kinase (PKA) and protein kinases C (PKC).

RESULTS

The antagonistic treatment showed the normal level of MEK 1/2, ERK 2, PKA and PKC by the combination treatment of morphine and E. cuneatum, comparable to the combination of morphine and methadone. Neuroblastoma cells exposed to morphine pre-treatment expressed a high level of MEK 1/2, ERK 2, PKA and PKC, while the treatments with E. cuneatum and methadone normalised the expression of the cellular adaptation proteins.

CONCLUSION

E. cuneatum exerted anti-addiction properties by lowering the levels of cellular adaptation proteins, and its effects are comparable to that of methadone (an established anti-addiction drug).

The Risk of Ventricular Dysrhythmia or Sudden Death in Patients Receiving Serotonin Reuptake Inhibitors With Methadone: A Population-Based Study

Background: Methadone is associated with ventricular dysrhythmias and sudden death. Serotonin reuptake inhibitors (SRIs) may increase the risk of these events either by inhibiting metabolism of methadone’s proarrhythmic (S)-enantiomer, additive QT interval prolongation, or both. We sought to determine whether certain SRIs were associated with a higher risk of methadone-related ventricular dysrhythmias or sudden death.

Methods: We conducted a nested case-control study of Ontario residents receiving methadone between April 1, 1996 and December 31, 2017. Cases, defined as patients who died of sudden cardiac death or were hospitalized with a ventricular dysrhythmia while on methadone, were matched with up to four controls who also received methadone on age, sex, and a disease risk score. We determined the odds ratio (OR) and p-value functions for the association between methadone-related cardiotoxicity and treatment with SRIs known to inhibit metabolism of (S)-methadone (paroxetine, fluvoxamine, sertraline) or prolong the QT interval (citalopram and escitalopram). Patients who were not treated with an SRI served as the reference group.

Results: During the study period, we identified 626 cases and 2,299 matched controls. Following multivariable adjustment, we found that recent use of sertraline, fluvoxamine or paroxetine (adjusted OR 1.30; 95% confidence intervals [CI] 0.90–1.86) and citalopram and escitalopram (adjusted OR 1.26; 95% CI 0.97–1.63) were associated with small increases in the risk methadone-related cardiac toxicity, an assertion supported by the corresponding p-value functions.

Interpretation: Certain SRIs may be associated with a small increase in cardiac toxicity in methadone-treated patients.

Comorbid Affective and Substance Use Disorders of Medicaid/Medicare Beneficiaries at an Opioid Treatment Program Serving Small Urban and Rural Communities

Objectives

Identify rates and correlates of comorbid affective and substance use disorders among an understudied population, Medicaid/Medicare beneficiaries receiving care at an opioid treatment program serving patients from small urban and rural areas. Examine whether past-year non-medical opioid use status differentiates comorbidity status.

Methods

A cross-sectional, venue-based design was used to recruit a convenience sample of patients treated with methadone for opioid use disorder. Measures were assessed across three domains: (1) demographic characteristics, (2) opioid use characteristics, and (3) comorbid disorders. Brief validated screeners categorized probable comorbid disorders. Bivariate analyses examined correlates of comorbid disorders and determined variable selection for multivariable analyses.

Results

In this sample (N = 210; mean age = 38.5 years; female = 62.2%; Non-Hispanic White race/ethnicity = 86.1%), comorbid disorders were common. Rates were as follows: current anxiety (48.1%), depression (41.1%), and PTSD (33.7%), and past-year stimulant (27.6%), marijuana (19.0%), alcohol (14.9%), and sedative (7.6%). In bivariate analyses, past-year non-medical opioid use and a greater accumulation of opioid use consequences were associated with most disorders. When including demographic and opioid use characteristics in multivariable analyses, past-year non-medical opioid use was associated with anxiety, PTSD, stimulant use disorder, and sedative use disorder.

Conclusions

Few studies have investigated comorbid disorders among this understudied population. This analysis highlights a high burden, especially for affective disorders. Our findings demonstrate that routine, ongoing assessment of non-medical opioid use may be a promising and feasible strategy to detect patients needing integrated care. Future research should investigate whether changes to assessment protocols at opioid treatment programs in small urban and rural settings facilitate care coordination.

Opioid harm reduction: A scoping review of physician and system-level gaps in knowledge, education, and practice

Background: Harm reduction includes treatment and prevention approaches rather than abstinence, as a public health strategy for mitigating the opioid epidemic. Harm reduction is a new strategy for many healthcare professionals, and gaps in knowledge and practices may lead to barriers to optimal treatment. Our objective was to identify and describe gaps in physicians' knowledge, education, and practice in harm reduction strategies related to opioid overdose. Methods: We searched the PubMed, CINAHL, and Web of Science databases for articles published between 2015 and 2021, published in English, containing empirical evidence, addressing opioid harm reduction, and identifying gaps in physicians' knowledge, education, or practice. Results: Thirty-seven studies were included. Studies examined how physicians' perceptions or stigma influenced harm reduction efforts and addressed clinical knowledge gaps in overdose treatment and prevention and OUD treatment. Less than half of the studies addressed access issues at the system level, above the individual healthcare professional. Conclusion: Individual-level interventions should be addressed with professional continuing education and curricular-based changes through experiential and interprofessional education. System-level gaps can be remedied by increasing patient access to care, creating policies favorable to harm reduction, and extending resources to provide harm reduction strategies.

Rediscovery of Methadone to Improve Outcomes in Pain Management

Clinically, methadone is most known for its use in the treatment of opioid maintenance therapy. However, methadone's pharmacological profile makes it an excellent analgesic that can enhance acute and chronic pain management. It is a potent μ-receptor agonist with a longer elimination half-life than most clinically used opioids. In addition, methadone inhibits serotonin and norepinephrine uptake, and it is an N-methyl-D-aspartate antagonist. These distinct analgesic pathways mediate hyperalgesic, allodynic, and neuropathic pain. Its unique analgesic properties provide several essential benefits in perioperative use, neuropathic pain, cancer, and noncancer pain. Despite these proven clinical utilities, methadone has not been used widely to treat acute and chronic pain in opioid naïve patients. This article describes the unique pharmacology of methadone and provides emerging evidence to support its application in acute and chronic pain management. Pain management options and guidelines for surgical patients on methadone are discussed as well.

Progress in pretreatment of methadone: an update since 2015

Methadone, a µ-opioid receptor agonist, is widely used in pain-relieving and treating opioid dependence. If not strictly controlled, as an opioid substitute, it can lead to abuse and cause more severe withdrawal responses than heroin. Also, overdose or abuse of this drug in clinical use may provide severe side effects such as apnea, circulatory collapse, cardiac arrest, and even death. For these reasons, simple, rapid, and efficient methods have been developed for the pretreatment of methadone. This review presents a comprehensive conclusion of the pretreatment methods used for methadone in various sample matrices, focusing on the developments since 2015. Traditionally used pretreatment methods like solid-phase extraction and liquid-liquid extraction are discussed and newly developed methods like solid-phase microextraction and liquid-liquid microextraction along with new materials applied are focused.

Community based buprenorphine micro-induction in the context of methadone maintenance treatment and fentanyl - Case report

INTRODUCTION

The micro-induction method of initiating buprenorphine is becoming a popular method for initiating buprenorphine in patients with Opioid Use Disorder, who are on full opioid agonists, either prescribed or non-prescribed, in order to avoid precipitated withdrawal. Given the rising concerns around illicit fentanyl use, this method of initiating buprenorphine has become another tool for clinicians to help patients with Opioid Use Disorder, even when multiple full opioid agonists are involved. While the process for initiating buprenorphine through this process is well studied, the characteristics of patients who are able to tolerate this initiation method in an outpatient setting is not.

CASE(S)

We present the cases of two patients with Opioid Use Disorder in a community-based methadone maintenance program in whom micro-induction methods were used to initiate buprenorphine without lowering the methadone dose. Both patients successfully transitioned to buprenorphine without precipitated withdrawal. One of the patients was also using fentanyl at the time of induction and was able to abstain from fentanyl use following the induction process.

CONCLUSION

Initiating Buprenorphine using micro-induction strategies in a community based outpatient clinic in patients who are already on full opioid agonists is feasible, in these particular cases, the methadone dose or concurrent fentanyl use did not affect the outcome. We present the characteristics of the patient and the community clinic hoping that this helps more clinicians in replicating this induction strategy.

Prevalence of illicit drug consumption in a population of Hanoi: an estimation using wastewater-based epidemiology

Illicit drug use is a serious issue in Vietnam, but information about their prevalence is scarce, mainly based on seizure data. Wastewater-based epidemiology (WBE) is an alternative tool for obtaining such information, especially when stigma related to drug use can hinder survey approaches. The study aimed to apply WBE to assess the prevalence of use of a range of illicit drugs in an urban population of Vietnam. A total of 184 wastewater samples were collected at two different sites along a sewage canal, receiving sewage from over 400,000 people in Hanoi, Vietnam, in three different periods between 2018 and 2020. Illicit drugs and their metabolites were measured by direct injection using liquid chromatography-tandem mass spectrometry. The results were back-estimated, normalised to per capita daily consumption for assessement of consumption patterns and trends. Most drugs were detected in all the samples except cocaine, benzoylecgonine, amphetamine indicating a low prevalence of cocaine and amphetamine use. The estimated consumption level of methamphetamine was varied from 119.5 to 553.5 mg/d/1000 pp. The market of illicit drugs in Vietnam has changed from opiates to amphetamine-type simulants, and methamphetamine has replaced heroin as the No.1 drug, its use can be as much as 3 times more than heroin use. Moreover, we observed the considerable and potentially increasing level of ketamine consumption in Hanoi. No statistical difference was found in daily consumption per capita among days of the week for any drugs, both legal (codeine, methadone) and illegal (methamphetamine, MDMA, ketamine and heroin), suggesting the drugs were consumed mainly by regular users. This study provides important information related the illicit drug consumption in Vietnam, which will help to formulate appropriate drug control policies in this country.

Organ pathologies detected post-mortem in patients receiving opioid agonist treatment for opioid use disorder: a nation-wide 2-year cross-sectional study

AIMS

To document organ pathologies detected post-mortem in patients receiving opioid agonist treatment for opioid use disorder and estimate the extent to which individual characteristics are associated with pulmonary, cardiovascular, hepatic or renal pathologies.

DESIGN

Two-year cross-sectional nation-wide study.

SETTING

Norway.

PARTICIPANTS

Among all 200 patients who died during opioid agonist treatment between 1 January 2014 and 31 December 2015, 125 patients (63%) were autopsied. Among these, 122 patients (75% men) had available autopsy reports and were included. The mean age at the time of death was 48 years.

MEASUREMENTS

Information on pulmonary, cardiovascular, hepatic and renal pathologies were retrieved from forensic or medical autopsy reports, with no (0) and yes (1) as outcome variables and age, sex and body mass index as covariates in logistic regression analyses.

FINDINGS

Pathologies in several organs were common. Two-thirds (65%) of the decedents had more than two organ system diseases. The most common organ pathologies were chronic liver disease (84%), cardiovascular disease (68%) and pulmonary emphysema (41%). In bivariate analyses, only older age was associated with any pulmonary pathology [odds ratio (OR) = 1.06; 95% confidence interval (CI) = 1.01-1.10], cardiovascular pathology (OR = 1.11; 95% CI = 1.05-1.17) and renal pathology (OR = 1.05; 95% CI = 1.00-1.11). Older age remained independently associated with cardiovascular pathology (OR = 1.10; 95% CI = 1.04-1.16) and renal pathology (OR = 1.06; 95% CI = 1.01-1.12) adjusted for body mass index and sex.

CONCLUSIONS

Among autopsied Norwegians who died during opioid agonist treatment in 2014 and 2015, two-thirds had more than two organ system diseases, despite their mean age of 48 years at the time of death. Older age was independently associated with at least one cardiovascular or renal pathology after adjusting for sex and body mass index.

Sex-Dependent Synaptic Remodeling of the Somatosensory Cortex in Mice With Prenatal Methadone Exposure

Rising opioid use among pregnant women has led to a growing population of neonates exposed to opioids during the prenatal period, but how opioids affect the developing brain remains to be fully understood. Animal models of prenatal opioid exposure have discovered deficits in somatosensory behavioral development that persist into adolescence suggesting opioid exposure induces long lasting neuroadaptations on somatosensory circuitry such as the primary somatosensory cortex (S1). Using a mouse model of prenatal methadone exposure (PME) that displays delays in somatosensory milestone development, we performed an un-biased multi-omics analysis and investigated synaptic functioning in the primary somatosensory cortex (S1), where touch and pain sensory inputs are received in the brain, of early adolescent PME offspring. PME was associated with numerous changes in protein and phosphopeptide abundances that differed considerably between sexes in the S1. Although prominent sex effects were discovered in the multi-omics assessment, functional enrichment analyses revealed the protein and phosphopeptide differences were associated with synapse-related cellular components and synaptic signaling-related biological processes, regardless of sex. Immunohistochemical analysis identified diminished GABAergic synapses in both layer 2/3 and 4 of PME offspring. These immunohistochemical and proteomic alterations were associated with functional consequences as layer 2/3 pyramidal neurons revealed reduced amplitudes and a lengthened decay constant of inhibitory postsynaptic currents. Lastly, in addition to reduced cortical thickness of the S1, cell-type marker analysis revealed reduced microglia density in the upper layer of the S1 that was primarily driven by PME females. Taken together, our studies show the lasting changes on synaptic function and microglia in S1 cortex caused by PME in a sex-dependent manner.