Methadone, Buprenorphine, and Naltrexone for the Treatment of Opioid Use Disorder in Pregnant Women

Opioid Maintenance Therapy: A Review of Methadone, Buprenorphine, and Naltrexone Treatments for Opioid Use Disorder

The rates of opioid use and opioid related deaths are escalating in the United States. Despite this, evidence-based treatments for Opioid Use Disorder are underutilized. There are three medications FDA approved for treatment of Opioid Use Disorder: Methadone, Buprenorphine, and Naltrexone. This article reviews the history, criteria, and mechanisms associated with Opioid Use Disorder. Pertinent pharmacology considerations, treatment strategies, efficacy, safety, and challenges of Methadone, Buprenorphine, and Naltrexone are outlined. Lastly, a practical decision making algorithm is discussed to address pertinent psychiatric and medical comorbidities when prescribing pharmacology for Opioid Use Disorder.

Neurobehavioral outcomes of infants exposed to buprenorphine-naloxone compared with naltrexone during pregnancy

BACKGROUND

Naltrexone is a medication used to treat both opioid and alcohol use disorder with limited experience in pregnant individuals, particularly in comparison to more commonly utilized treatments such as buprenorphine-naloxone. The long-term outcomes of infants exposed to naltrexone has not been previously examined.

AIMS

To compare the neurobehavioral outcomes of naltrexone versus buprenorphine-naloxone exposed infants.

STUDY DESIGN

Multi-centered prospective cohort study.

SUBJECTS

Pregnant people on prescribed buprenorphine-naloxone or naltrexone were enrolled during pregnancy and the dyad followed until 12 months after delivery.

OUTCOME MEASURES

Infants were evaluated at 4-6 weeks corrected gestational age (CGA) using the NICU Neonatal Neurobehavioral Scale (NNNS) and at the 12-month CGA visit using the Ages and Stages Questionnaire, Third Edition (ASQ-3).

RESULTS

There were 7 dyads in the naltrexone group and 34 in the buprenorphine-naloxone group. On the NNNS, infants exposed to naltrexone had higher median scores for arousal and excitability, and lower median scores for attention and regulation at 4-6 weeks CGA compared to the buprenorphine-naloxone group. None of the infants in the naltrexone group were monitored for NOWS and had shorter length of hospital stay compared with the buprenorphine-naloxone group. Although no statistically significant differences were observed, more infants in the buprenorphine-naloxone group were identified as at risk for development delays in the communication, problem solving, and personal social domains of the ASQ-3 at 12 months CGA. Results should be interpreted with caution given this study's small sample size and lack of a prospective comparison cohort.

CONCLUSIONS

In this small cohort, there are differences noted in infant neurobehavior by NNNS at 4-6 weeks of age when comparing the buprenorphine-naloxone and naltrexone groups. At 12 months, ASQ-3 scores were similar but with percentage differences in potential development delay risk observed between the two groups. Larger cohort studies are needed to determine the long-term child outcomes after naltrexone exposure in pregnancy.

Prevalence and predictors of medication for opioid use disorder among reproductive-aged women

Background

Women of reproductive age would benefit from treatment of opioid use disorder (OUD) prior to pregnancy to improve maternal and infant outcomes. In this study, we aimed to identify the prevalence of medication for OUD (MOUD) and characterize correlates of MOUD receipt among 12-49-year-old women with OUD seeking treatment in publicly funded substance use disorder treatment programs at the time of their first treatment episode.

Methods

This cross-sectional study explores the demographic and clinical characteristics of women of reproductive age with OUD receiving publicly funded substance use treatment services. We used data from the concatenated 2015-2021 Treatment Episode Data Set-Admissions (TEDS-A), which documents demographic and clinical characteristics of patient admissions to publicly funded substance use treatment services in the United States.

Results

In the sample of females aged 12-49 with no prior treatment admissions and primary OUD (n=325,512), 40.53% received MOUD (n=131,930), including 39.40% of non-pregnant women (n=115,315) and 52.79% of pregnant women (n=8423). Pregnant women had significantly higher odds of receiving MOUD (aOR = 2.42, 95%CI: 2.30, 2.54) compared to non-pregnant women. Non-white race, treatment setting, and treatment self-referral were also associated with higher levels of MOUD.

Conclusions

We identified a significant unmet need among both pregnant and non-pregnant women with OUD seeking care in publicly funded treatment clinics. While women who are pregnant are significantly more likely to receive evidence-based treatment with MOUD, still 47.21% of pregnant women did not receive MOUD. All reproductive-aged women with OUD should be offered evidence-based treatment options, including MOUD.

Access to Services for Pregnant People With Opioid Use Disorder in Jails in the United States

The aim of this study was to assess the availability of medications for opioid use disorder (MOUD) and other services for pregnant people in jails in counties heavily impacted by opioid overdose in the United States. Counties were selected based on absolute number and population rate of opioid-overdose fatalities. Structured interviews were completed with representatives from 174 jails that house pregnant women. Descriptive statistics examine MOUD availability and differences in service provision and community-level characteristics based on MOUD availability. Most jails in the study sample (84.5%) had MOUD available for pregnant people; however, less than half of these jails ensured continuity of care. Jails without MOUD available are more likely to provide non-MOUD substance use services. These jails are more often located in smaller, rural counties in the Midwest and have higher rates of White residents and lower rates of Hispanic and African American residents. Gaps in MOUD availability in jails and continuity of care violate medical guidelines for treatment of pregnant patients with opioid use disorder and increase their risk of overdose. In addition, there are disparities across communities in access to MOUD for pregnant people in jails.

A Pathway to Treatment for Pregnant Women With Opioid Use Disorder

BACKGROUND

Addiction to opioids, a well-known public health crisis, is now more prevalent in pregnant women as evidenced by the parallel rise with pregnant women in the epidemic with the general population. Evidence is now available that substantiates the need for global awareness to increase efforts in the treatment of pregnant women with opioid use disorder (OUD) as this vulnerable population lacks equal access to opioid abuse treatment across the United States.

AIM

The overarching aim and purpose of this quality improvement project was to increase access to treatment for pregnant women with OUD who are currently underserved in a community located in Florida.

METHODS

Between January and April 2022, the 4Ps (parents, partners, past, and pregnancy), a validated screening tool, was implemented in an organization that accepts individuals with substance abuse. Each positive screen was referred for assessment for buprenorphine induction and medication-assisted treatment follow-up. Descriptive statistics were collected counting the number of screens completed, the number of positive screens, the number of referrals, and the number of patients remaining in treatment for 30 and 60 days.

RESULTS

Twenty-two screens were completed. The results yielded an increase in referrals, a 75% increase in treatment of pregnant women, and an average of 83% of participants remained in treatment.

CONCLUSION

The implementation of a validated screening tool assisted in increasing access to treatment for pregnant women with OUD. Once implemented, the screening tool forges a pathway for referrals and evidence-based treatment for pregnant women with OUD.

Comparisons of stress-related neuronal activation induced by restraint in adult male rat offspring with prenatal exposure to buprenorphine, methadone, or morphine

Prenatal opioid exposure may impede the development of adaptive responses to environmental stimuli by altering the stress-sensitive brain circuitry located at the paraventricular nucleus of the hypothalamus (PVH) and locus coeruleus (LC). Corticotropin-releasing factor (CRF) released from neurons in the PVH has emerged as a key molecule to initiate and integrate the stress response. Methadone (Meth) and buprenorphine (Bu) are two major types of synthetic opioid agonists for first-line medication-assisted treatment of opioid (e.g., morphine, Mor) use disorder in pregnant women. No studies have compared the detrimental effects of prenatal exposure to Meth versus Bu on the stress response of their offspring upon reaching adulthood. In this study, we aimed to compare stress-related neuronal activation in the PVH and LC induced by restraint (RST) stress in adult male rat offspring with prenatal exposure to the vehicle (Veh), Bu, Meth, or Mor. CFos-immunoreactive cells were used as an indicator for neuronal activation. We found that RST induced less neuronal activation in the Meth or Mor exposure groups compared with that in the Bu or Veh groups; no significant difference was detected between the Bu and Veh exposure groups. RST-induced neuronal activation was completely prevented by central administration of a CRF receptor antagonist (α-helical CRF_9-41, 10 μg/3 μL) in all exposure groups, suggesting the crucial role of CRF in this stress response. In offspring without RST, central administration of CRF (0.5 μg/3 μL)-induced neuronal activation in the PVH and LC. CRF-induced neuronal activation was lessened in the Meth or Mor exposure groups compared with that in the Bu or Veh groups; no significant difference was detected between the Bu and Veh exposure groups. Moreover, RST- or CRF-induced neuronal activation in the Meth exposure group was comparable with that in the Mor exposure group. Further immunohistochemical analysis revealed that the Meth and Mor exposure groups displayed less CRF neurons in the PVH of offspring with or without RST compared with the Bu or Veh groups. Thus, stress-induced neuronal activation in the PVH and LC was well preserved in adult male rat offspring with prenatal exposure to Bu, but it was substantially lessened in those with prenatal exposure to Meth or Mor. Lowered neuronal activation found in the Meth or Mor exposure groups may be, at least in part, due to the reduction in the density of CRF neurons in the PVH.

Opioid Use in Pregnancy: A Review

Importance

The use and misuse of opioids in pregnancy have been increasing and are a major public health issue. Opioid use in pregnancy and during lactation has been associated with increased maternal and neonatal morbidity and mortality.

Objective

This review aims to summarize the existing literature and current recommendations for opioid use while pregnant or lactating.

Evidence Acquisition

A PubMed, Cochrane Library, and Google Scholar literature search using the following terms was performed to gather relevant data: "opioids," "opioid maintenance therapy," "opioid use disorder," "suboxone," "buprenorphine," "methadone," "medication for opioid use disorder," "fetal outcomes," "perinatal outcomes," "pregnancy," "lactation," and "neonatal abstinence syndrome."

Results

Available studies on opioid use in pregnancy and during lactation were reviewed and support association with increased odds of maternal death, placental insufficiency, cardiac arrest, preterm birth, neonatal intensive care unit admission, low birth weight, and small for gestational age infants. Studies were also reviewed on pharmacotherapy options in pregnancy and promising prenatal care models.

Conclusion and Relevance

There is a critical need for research on the effects of opioid use and related pharmacotherapy options in pregnancy. Once the adverse perinatal effects of opioid exposure are identified and well-characterized, patient education, intervention, and antenatal surveillance can be developed to predict and mitigate its impact on maternal and fetal health.

Effects of prenatal opioid exposure on synaptic adaptations and behaviors across development

In this review, we focus on prenatal opioid exposure (POE) given the significant concern for the mental health outcomes of children with parents affected by opioid use disorder (OUD) in the view of the current opioid crisis. We highlight some of the less explored interactions between developmental age and sex on synaptic plasticity and associated behavioral outcomes in preclinical POE research. We begin with an overview of the rich literature on hippocampal related behaviors and plasticity across POE exposure paradigms. We then discuss recent work on reward circuit dysregulation following POE. Additional risk factors such as early life stress (ELS) could further influence synaptic and behavioral outcomes of POE. Therefore, we include an overview on the use of preclinical ELS models where ELS exposure during key critical developmental periods confers considerable vulnerability to addiction and stress psychopathology. Here, we hope to highlight the similarity between POE and ELS on development and maintenance of opioid-induced plasticity and altered opioid-related behaviors where similar enduring plasticity in reward circuits may occur. We conclude the review with some of the limitations that should be considered in future investigations. This article is part of the Special Issue on 'Opioid-induced addiction'.

A Systematic Scoping Review of Peridelivery Pain Management for Pregnant People With Opioid Use Disorder: From the Society for Obstetric Anesthesia and Perinatology and Society for Maternal Fetal Medicine

The prevalence of pregnant people with opioid use disorder (OUD), including those receiving medications for opioid use disorder (MOUD), is increasing. Challenges associated with pain management in people with OUD include tolerance, opioid-induced hyperalgesia, and risk for return to use. Yet, there are few evidence-based recommendations for pain management in the setting of pregnancy and the postpartum period, and many peripartum pain management studies exclude people with OUD. This scoping review summarized the available literature on peridelivery pain management in people with OUD, methodologies used, and identified specific areas of knowledge gaps. PubMed and Embase were comprehensively searched for publications in all languages on peripartum pain management among people with OUD, both treated with MOUD and untreated. Potential articles were screened by title, abstract, and full text. Data abstracted were descriptively analyzed to map available evidence and identify areas of limited or no evidence. A total of 994 publications were imported for screening on title, abstracts, and full text, yielding 84 publications identified for full review: 32 (38.1%) review articles, 14 (16.7%) retrospective studies, and 8 (9.5%) case reports. There were 5 randomized controlled trials. Most studies (64%) were published in perinatology (32; 38.1%) journals or anesthesiology (22; 26.2%) journals. Specific areas lacking trial or systematic review evidence include: (1) methods to optimize psychological and psychosocial comorbidities relevant to acute pain management around delivery; (2) alternative nonopioid and nonpharmacologic analgesia methods; (3) whether or not to use opioids for severe breakthrough pain and how best to prescribe and monitor its use after discharge; (4) monitoring for respiratory depression and sedation with coadministration of other analgesics; (5) optimal neuraxial analgesia dosing and adjuncts; and (6) benefits of abdominal wall blocks after cesarean delivery. No publications discussed naloxone coprescribing in the labor and delivery setting. We observed an increasing number of publications on peripartum pain management in pregnant people with OUD. However, existing published works are low on the pyramid of evidence (reviews, opinions, and retrospective studies), with a paucity of original research articles (<6%). Opinions are conflicting on the utility and disutility of various analgesic interventions. Studies generating high-quality evidence on this topic are needed to inform care for pregnant people with OUD. Specific research areas are identified, including utility and disutility of short-term opioid use for postpartum pain management, role of continuous wound infiltration and truncal nerve blocks, nonpharmacologic analgesia options, and the best methods to support psychosocial aspects of pain management.

Effects of prenatal opioid and alcohol exposures on immune and serotonin factors in human placenta

PURPOSE

Opioids and alcohol impact critical serotonin (5-HT) function in the developing placenta and fetus through the actions of immune proinflammatory factors. Yet, possible convergent effects of opioids and alcohol on human placental toll-like receptor 4 (TLR4) activation and subsequent 5-HT homeostasis remain entirely unknown. The purpose of this study was to examine the effect of prenatal exposure to opioids with or without prenatal alcohol exposure (PAE) on the expression of key placental immune and serotonin signaling factors in human placental tissue obtained from a well-characterized prospective cohort.

METHODS

Data were collected from a subset of participants enrolled in the prospective pre-birth Ethanol, Neurodevelopment, Infant, and Child Health (ENRICH-1) cohort. Women were recruited and classified into four study groups: 1) PAE (n = 20); 2) those taking medications for opioid use disorder (MOUD; n = 28), 3) concurrent PAE and MOUD (n = 20); and 4) controls (HC; n = 20) based on prospective, repeated self-report, and biomarker analysis. Placenta samples underwent tissue processing to identify mRNA for TLR4, nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), serotonin transporter (SERT), tryptophan hydroxylase (TPH1), indoleamine 2,3-Dioxygenase 1 (IDO) as well as protein concentrations of TLR4, IL-1β, TNF-α, SERT. To consider the association between study group and mRNA/protein expression of our targets, multivariable regression models were developed with inclusion of a priori selected covariates.

RESULTS

There was a significant negative association between PAE and SERT mRNA (β = -0.01; p < 0.01) and a positive association with TPH1 mRNA expression (β = 0.78; p < 0.05). In addition, there was a negative association between MOUD and TNF-α protein expression (β = -0.12; p < 0.05).

CONCLUSIONS

This study provides the first evidence that PAE may inhibit SERT expression while simultaneously promoting increased TPH1 protein expression in human placenta. This may result in increased 5-HT in fetal circulation known to affect neurodevelopment. Our data suggest that opioids and alcohol may disturb the bidirectional, dynamic interaction between the placental immune and serotonin system. Given the implication for brain development and health across the life-span further investigation of these critical mechanisms in well-defined cohorts is required.

Opioid exposure during pregnancy and the risk of congenital malformation: a meta-analysis of cohort studies

BACKGROUND

Opioid exposure during pregnancy has increased alarmingly in recent decades. However, the association between prenatal opioid exposure and congenital malformation risk has still been controversial. We aim to assess the association between opioid exposure during pregnancy and the risk of congenital malformations.

METHOD

PubMed, Embase, and Cochrane library of clinical trials were systematically searched to September 13th, 2021. Cohort studies reporting risk of congenital malformation after opioid exposure compared with non-exposure during pregnancy were included. Risk of studies was appraised with the ROBINS-I tool. Meta-analysis was conducted using the random-effects model. Subgroup analyses were conducted for the primary outcome based on indication, exposed period, whether adjusted data was used, and risk of bias assessment. Meta-regression was performed to evaluate the relation of publication year.

MAIN RESULTS

Eighteen cohort studies with 7,077,709 patients were included. The results showed a significant increase in the risk of overall congenital malformation (RR = 1.30, 95%CI: 1.11-1.53), major malformation (RR = 1.57, 95%CI:1.11-2.22), central nervous system malformation (RR = 1.36, 95% CI:1.19-1.55), and limb malformation (RR = 2.27, 95%CI:1.29-4.02) with opioid exposure during pregnancy. However, the predictive interval conveyed a different result on overall congenital malformation (95%PI: 0.82-2.09) and major malformation (95%PI: 0.82-2.09). No association between opioid exposure and overall congenital malformation in the first trimester (RR = 1.12, 95%CI:0.97-1.31) and prescribed for analgesic or antitussive treatment (RR = 1.03, 95%CI:0.94-1.13) were observed. In subgroups that study provided data adjusted for confounders (RR = 1.06, 95%CI:0.93-1.20) or identified moderate or serious risk of bias (RR = 1.00, 95%Cl: 0.85-1.16; RR = 1.21, 95%Cl: 1.60-2.68), no association was found.

CONCLUSION

Opioid exposed in the first trimester or prescribed for analgesic or antitussive treatment did not increase the risk of overall congenital malformation. The findings should be discussed in caution considering the situation of individual patients and weigh out its potential risk of congenital malformation.

TRIAL REGISTRATION

Registration number: CRD42021279445 .

The Potential of Methocinnamox as a Future Treatment for Opioid Use Disorder: A Narrative Review

The opioid epidemic is an ongoing public health crisis, and the United States health system is overwhelmed with increasing numbers of opioid-related overdoses. Methocinnamox (MCAM) is a novel mu opioid receptor antagonist with an extended duration of action. MCAM has potential to reduce the burden of the opioid epidemic by being used as an overdose rescue treatment and a long-term treatment for opioid use disorder (OUD). The currently available treatments for OUD include naloxone, naltrexone, and methadone. These treatments have certain limitations, which include short duration of action, patient non-compliance, and diversion. A narrative review was conducted using PubMed and Google Scholar databases covering the history of the opioid epidemic, pain receptors, current OUD treatments and the novel drug MCAM. MCAM could potentially be used as both a rescue and long-term treatment for opioid misuse. This is due to its pseudo-irreversible antagonism of the mu opioid receptor, abnormally long duration of action of nearly two weeks, and the possibility of using kappa or delta opioid receptor agonists for pain management during OUD treatment. MCAM’s novel pharmacokinetic and pharmacodynamic properties open a new avenue for treating opioid misuse.

Transport of Maternally Administered Pharmaceutical Agents Across the Placental Barrier In Vitro

To understand the transport of pharmaceutical agents and their effects on developing fetus, we have created a placental microsystem that mimics structural phenotypes and physiological characteristic of a placental barrier. We have shown the formation of a continuous network of epithelial adherens junctions and endothelial cell-cell junctions confirming the integrity of the placental barrier. More importantly, the formation of elongated microvilli under dynamic flow condition is demonstrated. Fluid shear stress acts as a mechanical cue triggering the microvilli formation. Pharmaceutical agents were administered to the maternal channel, and the concentration of pharmaceutical agents in fetal channel for coculture and control models were evaluated. In fetal channel, the coculture model exhibited about 2.5 and 2.2% of the maternal initial concentration for naltrexone and 6β-naltrexol, respectively. In acellular model, fetal channel showed about 10.5 and 10.3% of the maternal initial concentration for naltrexone and 6β-naltrexol, respectively. Gene expressions of epithelial cells after direct administration of naltrexone and 6β-naltrexol to the maternal channel and endothelial cells after exposure due to transport through placental barrier are also reported.

Disparities in opioid treatment access and retention among women based on pregnancy status from 2006 to 2017

Background:

The purpose of this study is to assess differences in wait time and retention in opioid use disorder (OUD) treatment among a sample of pregnant and non-pregnant women from low-income urban communities in Los Angeles, California.

Methods:

Data were collected in 9 waves consisting of consecutive years from 2006 to 2011, and then including 2013, 2015, and 2017. The sample consisted of 12,558 women, with 285 being pregnant and 12,273 being non-pregnant. We compared pregnant women with non-pregnant women at admission on key characteristics and relied on two multilevel negative binomial regressions analyses to examine factors related to access (days on the waiting list) and retention (days in treatment).

Results:

We detected disparities existed in access and retention. Pregnant women spent less time waiting to initate treatment than non-pregnant women and, once in treatment, had longer treatment episodes. Among pregnant women, clients identifying as Latina or Other waited longer to enter treatment compared to clients identifying as non-Latina White or Black. Women entering residential waited longer than those entering methadone or counseling services. Pregnant women were more likely to be in treatment longer if they had mental health issues, greater parenting responsibilities (number of children less than 18), and greater SUD severity (number of prior treatment episodes).

Conclusions:

Findings suggest pregnant women’s access and retention can be improved through Medicaid coverage and through the implementation of a standard of care that includes MOUD (methadone) along with ancillary health and social services.

Outcomes of Neonates Exposed to Buprenorphine versus Methadone in Utero: A Systematic Review and Meta-Analysis of Safety in the Fetus and Neonate

We assessed the prevalence of neonatal abstinence syndrome (NAS) and fetal growth outcomes in neonates exposed to methadone compared to buprenorphine in utero. Three authors assessed the titles and abstracts of all potentially eligible studies. The selection criteria were randomized controlled trials and observational cohort studies from January 2000 to January 2020 which indexed and reported original data for occurrence of NAS and fetal growth outcomes in pregnant people who received methadone vs. buprenorphine treatment. The quality and possible bias of each study was assessed using the Cochrane-risk-of-bias tool. Data were pooled to compare the occurrence of NAS and fetal growth restriction among women who received methadone vs. buprenorphine treatment. Of the 106 articles screened, 1 randomized controlled trial and 5 observational cohort studies including 2041 pregnancies fulfilled the inclusion criteria. Buprenorphine is associated with less NAS and improved growth outcomes compared to methadone. (OR = 0.515; p-value < 0.001). Compared to methadone, buprenorphine is associated with less adverse neonatal outcomes in terms of gestational age at birth, birthweight, and head circumference. With the prevalence of NAS continuing to rise, this study adds to the expanding academic research aimed at creating safer treatment protocols.

Underrepresentation of diverse populations and clinical characterization in opioid agonist treatment research: A systematic review of the neurocognitive effects of buprenorphine and methadone treatment

INTRODUCTION

The relative neurocognitive effects of the two most common opioid agonist treatments (OAT; buprenorphine and methadone) for opioid use disorder (OUD) are poorly understood. The aim of this systematic review is to examine the neurocognitive effects of OAT (buprenorphine and methadone) and the clinical and sociodemographic characteristics of study samples.

METHODS

The research team queried PubMed, PsycINFO and Cochrane Reviews for articles (01/1980-01/2020) with terms related to neurocognitive testing in adults (age ≥ 18) prescribed OAT. The team extracted neurocognitive data and grouped them by domain (e.g., executive functioning, learning/memory), and assessed study quality.

RESULTS

The search retrieved 2341 abstracts, the team reviewed 278 full articles, and 32 met inclusion criteria. Of these, 31 were observational designs and one was an experimental design. Healthy controls performed better across neurocognitive domains than OAT-treated persons (buprenorphine or methadone). Compared to those with active OUD, OAT-treated persons had better neurocognition in various domains. However, in seven studies comparing buprenorphine- and methadone-treated persons, buprenorphine was associated with better neurocognition than was methadone, with moderate to large effect sizes in executive functioning, attention/working memory, and learning/memory. Additionally, OAT research underreports clinical characteristics and underrepresents Black and Latinx adults, as well as women.

CONCLUSIONS

Findings suggest that compared to active opioid use, both buprenorphine and methadone treatment are associated with better neurocognitive functioning, but buprenorphine is associated with better executive functioning, attention/working memory, and learning/memory. These findings should be interpreted with caution given widespread methodological heterogeneity, and limited representation of ethnoracially diverse adults and women. Rigorous longitudinal comparisons with more diverse, better characterized samples will help to inform treatment and policy recommendations for persons with OUD.

Understanding ED Buprenorphine Initiation for Opioid Use Disorder: A Guide for Emergency Nurses

Opioid use disorder is a critical public health problem that continues to broaden in scope, adversely affecting millions of people worldwide. Significant efforts have been made to expand access to medication therapy for opioid use disorder, in particular buprenorphine. As the emergency department is a critical point of access for many patients with opioid use disorder, the initiation of buprenorphine therapy in the emergency department is increasing, and emergency nurses should be familiar with the care of these vulnerable patients. The purpose of this article is to provide a clinical review of opioid use disorder and opioid withdrawal syndrome, medication treatments for opioid use disorder, best clinical practices for ED-initiated buprenorphine therapy, assessment of withdrawal symptoms, discharge considerations, and concerns for special populations. With expanded understanding of opioid use disorder, withdrawal, and available treatments, emergency nurses will be better prepared to deliver and support life-saving treatments for patients and families suffering from this disease. In addition, emergency nurses are well positioned to play an important role in public health advocacy around opioid use disorder, providing critical support for destigmatization and expanded access to safe and efficacious treatments.

Executive Summary of the Focused Update of the ASAM National Practice Guideline for the Treatment of Opioid Use Disorder

: A Focused Update of the ASAM National Practice Guideline for the Treatment of Opioid Use Disorder is published in the current issue of the Journal of Addiction Medicine. The focused update included a search of Medline's PubMed database from January 1, 2014 to September 27, 2018, as well as a search of the grey literature (archives of the Clinical Guideline Clearinghouse, and key agency and society websites) for new practice guidelines and relevant systematic reviews addressing the use of medications and psychosocial treatments in the treatment of opioid use disorder, including within special populations. The search identified 11 practice guidelines and 35 systematic reviews that informed the subsequent RAND/UCLA Appropriateness Method (RAM) process employed to facilitate the focused update by a National Guideline Committee of addiction experts. New and updated recommendations were included if they were considered: (a) clinically meaningful and applicable to a broad range of clinicians treating addiction involving opioid use; and (b) urgently needed to ensure the Practice Guideline reflects the current state of the science for the existing recommendations, aligns with other relevant practice guidelines, and reflects newly approved medications and formulations.

Therapeutic Approaches to Opioid Use Disorder: What is the Current Standard of Care?

Opioid use disorder is a frequent cause of suffering to communities worldwide. Therapeutic approaches to opioid use disorder include screening, appropriate assessment and diagnosis, consideration of level of care, acute management of overdose or withdrawal, treatment with medications, psychotherapeutic approaches, and community support. People who struggle with addiction to opioids often suffer deeply from direct and indirect consequences of use. Subsequently, it is critical that all medical providers understand the appropriate treatment options for opioid use disorder. This paper provides a comprehensive overview of the therapeutic options available for treatment of this chronic disease.

Affective decision-making in children prenatally exposed to opioids

Although opioid maintenance therapy (OMT) is currently recommended for pregnant opioid-dependent women, potential effects on children's long-term development are still largely unknown. The current study assessed the long-term cognitive development of children born to women in OMT. Particularly, children's decision-making performance was assessed with a child-friendly version of the Iowa Gambling Task. Using a prospective longitudinal design, a cohort of children was followed from birth to middle childhood. Data were collected in Norway between 2005 and 2017. Participants included 41 children (aged 9-11 years), 20 of whom had histories of prenatal methadone or buprenorphine exposure. Background data were collected from personal interviews and medical records in 2005-2006. Children's affective decision-making was assessed in 2016-2017. Results showed no main effect of group on the net scores in the gambling task, F(1, 39) = 1.44, p = 0.24, η² = 0.04, demonstrating no group differences in decision-making performance. A main effect of group was found on sensitivity to punishment, with children in the control group choosing the doors with the infrequent, but high punishment more often compared to children in the OMT group, F(1, 39) = 4.90, p = 0.03, η²  = 0.11. No main effect of group on decision-making speed was found, although results showed a significant interaction effect between group and gain, F(1, 8,194) = 4.09, p = 0.04, η²  = 0.001. Children prenatally exposed to opioids were found to have normal decision-making performance on an affective decision-making task and were able to consider future consequences when making decisions.

Bulleyaconitine A Inhibits Morphine-Induced Withdrawal Symptoms, Conditioned Place Preference, and Locomotor Sensitization Via Microglial Dynorphin A Expression

Bulleyaconitine A (BAA), a C19-diterpenoid alkaloid, has been prescribed as a nonnarcotic analgesic to treat chronic pain over four decades in China. The present study investigated its inhibition in morphine-induced withdrawal symptoms, conditioned place preference (CPP) and locomotor sensitization, and then explored the underlying mechanisms of actions. Multiple daily injections of morphine but not BAA up to 300 μg/kg/day into mice evoked naloxone-induced withdrawal symptoms (i.e., shakes, jumps, genital licks, fecal excretion and body weight loss), CPP expression, and locomotor sensitization. Single subcutaneous BAA injection (30–300 μg/kg) dose-dependently and completely attenuated morphine-induced withdrawal symptoms, with ED₅₀ values of 74.4 and 105.8 μg/kg in shakes and body weight loss, respectively. Subcutaneous BAA (300 μg/kg) also totally alleviated morphine-induced CPP acquisition and expression and locomotor sensitization. Furthermore, subcutaneous BAA injection also specifically stimulated dynorphin A expression in microglia but not astrocytes or neurons in nucleus accumbens (NAc) and hippocampal, measured for gene and protein expression and double immunofluorescence staining. In addition, subcutaneous BAA-inhibited morphine-induced withdrawal symptoms and CPP expression were totally blocked by the microglial metabolic inhibitor minocycline, dynorphin A antiserum, or specific KOR antagonist GNTI, given intracerebroventricularly. These results, for the first time, illustrate that BAA attenuates morphine-induced withdrawal symptoms, CPP expression, and locomotor sensitization by stimulation of microglial dynorphin A expression in the brain, suggesting that BAA may be a potential candidate for treatment of opioids-induced physical dependence and addiction.

Stigma Surrounding the Use of Medically Assisted Treatment for Opioid Use Disorder

This study sought to determine whether certain factors influenced public stigma toward the use of medication to treat opioid use disorders (MOUD). Method: In a series of 3 studies using between-subjects designs, hypothetical MOUD patients matched in age and educational status with the participants were varied in systematic ways to determine whether certain factors influenced stigmatizing views of the patients. Results: Study 1 (n = 142) determined that stigma levels were elevated for hypothetical patients receiving agonist medication for OUD compared to other medications or no medication at all. Study 2 (n = 144) found that hypothetical patients receiving opioid agonist medication for either heroin or pain pills were equally stigmatized and stigmatized more than hypothetical patients on nicotine agonist medication. Study 3 (n = 151) showed that stigmatizing attitudes did not change as a result of enhanced treatment services for hypothetical MOUD patients (i.e. therapy as a supplement to medication). Conclusions/Importance: Results indicate that patients receiving agonist medication for an OUD may be the target of public stigma. Public education on the efficacy of agonist medications for OUD is urgently needed to help reduce such stigma, which may facilitate treatment delivery, treatment adherence, and treatment success.

Methadone interrupts neural growth and function in human cortical organoids

Prenatal opioids exposure can lead to both neonatal abstinence syndrome in newborns and neurological deficits later in life. Although opioids have been well studied in general, the cellular and molecular mechanisms by which opioids affect human fetal brain development has not been well understood. In this work, we have taken advantage of a human 3D-brain cortical organoid (hCO) that facilitated enormously the investigation of early human brain development. Using imaging, immunofluorescence, multi-electrode array (MEA) and patch clamp recording techniques, we have investigated the effect of methadone, a frequently used opioid during pregnancy, on early neural development, including neuronal growth, neural network activity and synaptic transmission in hCOs. Our results demonstrated that methadone dose-dependently halted the growth of hCOs and induced organoid disintegration after a prolonged exposure. In addition, methadone dose-dependently suppressed the firing of spontaneous action potentials in hCOs and this suppression could be reversed upon methadone withdrawal in hCOs treated with lower dosages. Further investigation using patch clamp whole cell configuration revealed that, at clinically relevant concentrations, methadone decreased the frequency and amplitude of excitatory postsynaptic currents in neurons, indicating a critical role of methadone in weakening synaptic transmission in neural networks in hCOs. In addition, methadone significantly attenuated the voltage-dependent Na⁺ current in hCOs. We conclude that methadone interrupts neural growth and function in early brain development.

The antagonistic activity profile of naloxone in μ-opioid receptor agonist-induced psychological dependence

Naloxone is a μ-opioid receptor antagonist that has been used to prevent overdose-related respiratory depression and deaths by the illicit use of opioids. Naloxone can also deter the abuse potential of opioids, but little has been reported regarding its antagonistic activity profile against opioid-induced psychological dependence. This study aimed to confirm the antagonistic activity profile of naloxone against several μ-opioid receptor agonists and investigate whether naloxone could affect the psychological dependence induced by widely used μ-opioid receptor agonist, oxycodone. In the Guanosine-5'-o-(3-thio) triphosphate (GTPγS) binding assay, naloxone (30-30,000 nM) inhibited the GTPγS binding induced by oxycodone, hydrocodone, morphine, and fentanyl. It elicited parallel rightward shifts in the concentration-response curves, indicating that naloxone possessed a competitive antagonistic activity profile against these μ-opioid receptor agonists. In the conditioned place preference test, oxycodone (0.01-1 mg/kg, i.v.) produced dose-dependent increases in place preference. The increased place preference induced by oxycodone (1 mg/kg) was significantly attenuated by co-administration of naloxone at a dose of 0.5 mg/kg but not 0.01 mg/kg. Naloxone (0.5 mg/kg, i.v.) also blocked oxycodone (1 mg/kg)-induced dopamine release in nucleus accumbens; however, at a lower dose (0.01 mg/kg), it did not affect the intrinsic dopamine release by oxycodone. These results indicate that the psychological dependence of oxycodone could be antagonized by naloxone, depending on the dose. This characterization might lead to a better understanding of the competitive antagonistic activity profile of naloxone for μ-opioid receptor in the brain.

Continuous Epidural Hydromorphone Infusion for Post-Cesarean Delivery Analgesia in a Patient on Methadone Maintenance Therapy: A Case Report

The prevalence of opioid use disorder (OUD) in the United States has more than quadrupled over the past two decades. This patient population presents a number of challenges to clinicians, including difficult pain management after surgical procedures due to the development of opioid tolerance. Significantly greater opioid consumption and pain scores after cesarean delivery have been reported in patients with OUD compared to other obstetric patients. A multi-modal analgesic regimen is generally recommended, but there are few well-established pain management strategies after cesarean delivery specific to patients with OUD. We present the case of a patient with OUD maintained on daily methadone that received a continuous epidural hydromorphone infusion for post-cesarean analgesia, a technique not previously reported in obstetric patients and only rarely described for patients undergoing other surgical procedures. The patient received epidural anesthesia for cesarean delivery, and after surgery, the epidural catheter was left in place for the epidural hydromorphone infusion, initiated at 140 mcg/hr and continued for approximately 40 hrs. This strategy reduced her average daily oral opioid consumption by 97%, reduced self-reported pain scores, shortened the length of hospitalization and improved ability to ambulate compared to her previous cesarean delivery. The use of continuous epidural hydromorphone infusion was effective in this case, and this analgesic technique may also be applicable to other types of surgical procedures with the potential for significant post-operative pain, particularly in patients with OUD.

Opioid use disorder in pregnancy

The number of pregnant people affected by the opioid epidemic in the United States continues to rise. The following key aspects of opioid use disorder in pregnancy are explored through the progression of a pregnancy via a patient case: treatment options, treatment decisions, substance use screening, dosing modifications, and other aspects of peripartum care. Many factors affect opioid use disorder treatment choices during pregnancy; however, when a pregnant person is medically eligible for a therapy and multiple options are available locally, the ultimate decision regarding treatment selection should be left up to the patient and strong support services provided. This approach to treatment results in optimal maternal and neonatal outcomes and long-term maternal engagement and retention in care.

Opioid Use in Pregnancy

PURPOSE OF REVIEW

Perinatal opioid use is a major public health problem and is associated with a number of deleterious maternal and fetal effects. We review recent evidence of perinatal outcomes and treatment of opioid use disorder (OUD) during pregnancy.

RECENT FINDINGS

Opioid exposure in pregnancy is associated with multiple obstetric and neonatal adverse outcomes, with the most common being neonatal opioid withdrawal syndrome (NOWS). Treatment with buprenorphine or methadone is associated with NOWS, but neither medication appears to have significant adverse effects on early childhood development. Buprenorphine appears to be superior to methadone in terms of incidence and severity of NOWS in exposed infants. The long-term effects of opioid exposure in utero have been inconclusive, but recent longitudinal studies point to potential differences in brain morphology that may increase vulnerability to future stressors. Maintenance therapy with methadone or buprenorphine remains the standard of care for pregnant women with OUD given its consistent superiority to placebo in terms of rates of illicit drug use and pregnancy outcomes. New non-pharmacologic management options for NOWS appear promising. Future research is needed to further evaluate the effects of opioid exposure in utero and determine the optimal delivery model for maintenance therapy.

Risk Factors Associated with the Occurrence of Neonatal Opioid Withdrawal Syndrome: A Review

In a number of countries, the prevalence of neonatal opioid withdrawal syndrome (NOWS) is increasing. While NOWS is ultimately the result of opioid exposure in utero, a wide range of risk factors have been associated with the prevalence of NOWS, extending beyond just drug exposure. This article reviews the available literature on factors associated with the incidence of NOWS in opioid-exposed neonates. A range of risk factors have been associated with NOWS, including features of neonatal drug exposure, maternal and neonatal characteristics, aspects of labor and delivery, and genetics. Increased length of gestation and higher birth weight were consistently associated with an increased risk of NOWS, while breast feeding and 'rooming-in' were associated with a reduced risk of NOWS. Additionally, several genetic factors have also been associated with NOWS severity. There is conflicting evidence on the association between NOWS and other risk factors including opioid dose, neonate sex, and the use of some medications during pregnancy. This may be in part attributable to differences in how NOWS is diagnosed and the variety of methodologies across studies. While a large number of risk factors associated with NOWS are non-modifiable, encouraging pregnant women to reduce other drug use (including smoking), breast feed their child, and the judicious use of medications during pregnancy may help reduce the prevalence of NOWS. The presence or absence of NOWS in an opioid-exposed neonate is associated with a wide range of factors. Some of these modifiable risk factors may be potential targets for the primary prevention of NOWS.

Medication-Assisted Treatment for Opioid-Use Disorder

The United States is in the midst of a national opioid epidemic. Physicians are encouraged both to prevent and treat opioid-use disorders (OUDs). Although there are 3 Food and Drug Administration-approved medications to treat OUD (methadone, buprenorphine, and naltrexone) and there is ample evidence of their efficacy, they are not used as often as they should. We provide a brief review of the 3 primary medications used in the treatment of OUD. Using data from available medical literature, we synthesize existing knowledge and provide a framework for how to determine the optimal approach for outpatient management of OUD with medication-assisted treatments.

Naltrexone Treatment for Pregnant Women With Opioid Use Disorder Compared With Matched Buprenorphine Control Subjects

PURPOSE

The use of the opioid antagonist naltrexone (NTX) for pregnant women with opioid use disorder (OUD) remains understudied. The purpose of this pilot study was to examine pregnancy and neonatal outcomes in a cohort of NTX-treated women.

METHODS

This single-center, retrospective cohort study included 6 mother-infant dyads taking NTX compared with 13 taking buprenorphine (BUP) between 2017 and 2019. Maternal demographic characteristics, any unprescribed or illicit opioid use per urine toxicology or provider report during the pregnancy or 6 months' postdelivery, delivery outcomes, gestational age, birth weight, Apgar scores, neonatal intensive care unit admission, and neonatal abstinence syndrome (NAS) outcomes (NAS diagnosis, pharmacologic treatment, and total hospital length of stay) were compared.

FINDINGS

Maternal and infant demographic characteristics were similar between the 2 groups, with the exception of cigarette smoking in the BUP group being more common (92% vs 33%; P = 0.02). None of the women on NTX versus 23% of the women on BUP had documented opioid misuse (P = 0.52). No infants in the NTX group had a NAS diagnosis versus 92% in the BUP group (P < 0.001). Forty-six percent of the BUP-exposed infants were treated for NAS versus 0% in the NTX group (P < 0.001). NTX-exposed infants had a shorter length of stay (mean [SD], 3.2 [1.6] vs 10.9 [8.2] days; P = 0.008).

IMPLICATIONS

Maintaining women on NTX during pregnancy was associated with favorable outcomes. These results support the need for larger multicenter studies sufficiently powered to detect possible differences between the medications on long-term maternal and child safety and efficacy outcomes.

Safety of Psychotropic Medications During Pregnancy

Risks, benefits, alternatives, and appropriateness of psychotropic medications, including risks of no treatment, are discussed for antidepressants, mood-stabilizing medications, anxiolytic/sedative hypnotic medications, stimulants, and medication-assisted treatment of substance use disorders. Early screening, diagnosis, and intervention prior to and/or during pregnancy often reduce morbidity and mortality of mental health disorders for mothers and infants.

Benzodiazepine withdrawal in pregnant women with opioid use disorders: An observational study of current clinical practices at a tertiary obstetrical hospital

BACKGROUND

As more patients are admitted for medical complications related to opioid use disorders, physicians are called upon to manage withdrawal from co-occurring substance use disorders. We present an observational study of pregnant women with comorbid opioid and sedative-hypnotic use disorders hospitalized for benzodiazepine withdrawal.

OBJECTIVES

Our primary aims were to assess current practices in withdrawal management in the perinatal period in patients admitted to an antepartum unit at a tertiary care setting with comorbid opioid and sedative-hypnotic use disorders; specifically, to identify patterns of withdrawal management, including the type of withdrawal protocol utilized, the total dosage of benzodiazepine used during that protocol, to assess patient variables associated with higher dosing, and to analyze neonatal outcomes.

METHODS

A chart review of psychiatry consultations for benzodiazepine withdrawal in antepartum women was conducted for patients seen over a 3 year period with manual extraction of patient age, number of pregnancies, modality of benzodiazepine withdrawal management (symptom-triggered versus standing benzodiazepine taper), total amount of benzodiazepine used during the detoxification period, active methadone conversion versus stable methadone dose on admission, and average fetal heart tones during the withdrawal detoxification period.

RESULTS

The majority of patients (83%) were undergoing methadone conversion or were stable on methadone maintenance. The mean cumulative benzodiazepine dose used was 8.3 ± 10.5 mg in lorazepam equivalents. Women placed on a symptom-triggered protocol received lower mean benzodiazepine doses (2.4 ± 6.9 mg) compared to those on a benzodiazepine taper in conjunction with a symptom-triggered protocol (17.9 ± 20.6 mg; p < 0.001). Women who started methadone during admission tended to receive lower mean lorazepam doses (7.1 ± 10.4) compared to women admitted on stable outpatient doses of methadone (11.5 ± 10.6; p = 0.07). Using t-test and chi-square analyses on a subgroup of women (N = 50), no differences were found between women placed on a taper compared to a symptom-triggered scale alone in neonatal outcomes such as APGARS, NICU admissions, and preterm delivery with low rates of complications in both groups.

CONCLUSIONS

A symptom-triggered benzodiazepine withdrawal protocol was associated with significantly lower total benzodiazepine use compared to standing taper regimens. Women started on methadone during admission tended to receive lower lorazepam doses compared to women admitted on stable doses of methadone. Preliminary maternal/neonatal outcomes were similar between symptom-triggered and taper groups.

Impact of timing of methadone initiation on perinatal outcomes following delivery among pregnant women on methadone maintenance therapy in Ontario

BACKGROUND AND AIMS

Methadone maintenance therapy (MMT) is associated with improved outcomes for children exposed to maternal opioid dependence in utero. We examined Ontario's population of pregnant women on MMT and determined the impact of timing of MMT initiation on perinatal outcomes.

DESIGN

Cohort study.

SETTING

Ontario, Canada.

PARTICIPANTS

Women eligible for public drug benefits and on MMT during pregnancy between 2005 and 2015.

MEASUREMENTS

We stratified women based on their timing of MMT initiation: (1) stabilized prior to conception, (2) newly initiated prior to conception, (3) initiation in trimester 1, (4) initiation in trimester 2 or (5) initiation in trimester 3. The primary outcomes in the multivariable logistic regression analysis were key perinatal health indicators: small for gestational age, preterm birth, congenital anomalies, severe maternal morbidity, caesarean section and induced labor. Secondary outcomes were specific to maternal opioid dependence: neonatal abstinence syndrome (NAS), admission to a neonatal intensive care unit (NICU), NAS treatment, removal from mother's custody at hospital discharge and neonatal death.

FINDINGS

Among 1842 women on MMT during pregnancy, 87.6% (n = 1614) initiated MMT before conception. Almost a quarter of their infants (22.2%; n = 408) were born small for gestational age, 17.5% (n = 323) were preterm and 5.9% (n = 109) were born with a congenital anomaly. The odds of primary outcomes occurring did not differ based on timing of methadone initiation; however, infants of mothers who initiated methadone during pregnancy had up to a fourfold increase in the odds of social services removal at the hospital [adjusted odds ratio (aOR) range = 3.70-4.19] compared with those whose mothers were stabilized on MMT prior to conception.

CONCLUSIONS

Later initiation of methadone maintenance therapy among pregnant women in Ontario, Canada has not been found to be clearly related to most key perinatal adverse health outcomes.

Mechanisms and Clinical Features of Co-occurring Opioid and Nicotine Use

Purpose of review

To review the literature addressing shared pathophysiological and clinical features of opioid and nicotine use to inform etiology and treatment, and highlight areas for future research.

Recent findings

Opioid and nicotine use co-occur at an alarmingly high rate, and this may be driven in part by interactions between the opioid and cholinergic systems underlying drug reward and the transition to dependence. Pain, among other shared risk factors, is strongly implicated in both opioid and nicotine use and appears to play an important role in their co-occurrence. Additionally, there are important sex/gender considerations that require further study. Regarding treatment, smoking cessation can improve treatment outcomes in opioid use disorder, and pharmacological approaches that target the opioid and cholinergic systems may be effective for treating both classes of substance use disorders.

Summary

Understanding overlapping etiological and pathophysiological mechanisms of opioid and nicotine use can aid in understanding their co-occurrence and guiding their treatment.

Substance use in pregnancy: The medical challenge

Substance use contributes significantly to the global burden of disease. Growing numbers of women use nicotine, alcohol, and illicit substances. Women are the most vulnerable to problematic substance use in their reproductive years. The first 1000 days of life, starting at conception, have been established as a critical window of time for long-term health and development. Substance use in pregnancy is associated with negative pregnancy and child health outcomes. The impact of antenatal substance use on these outcomes needs to be considered within a challenging and complex context. This review provides an overview of the current literature on the impact of substances on pregnancy and child outcomes as well as the evidence and guidelines on screening and interventions for women using substances during pregnancy.