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

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.

Case Series of Individuals Treated With Naltrexone During Pregnancy for Opioid and/or Alcohol Use Disorder

OBJECTIVE

There is a lack of knowledge about the relative safety and efficacy of naltrexone for the treatment of pregnant individuals with opioid and/or alcohol use disorder, including the range of outcomes, in both the pregnant individual and the infant, over the course of peripartum period. Our objective was to describe these outcomes in a cohort of pregnant individuals on naltrexone.

METHODS

In this prospective case series, 7 pregnant individuals with opioid use disorder (OUD) or alcohol use disorder (AUD) treated with naltrexone were followed from pregnancy through 12 months after delivery. Clinical treatment protocols and outcomes related to safety and efficacy during pregnancy, delivery, and the postpartum period are described.

RESULTS

There were 4 pregnant individuals with OUD and 3 with AUD, of which 3 were managed with oral and 4 with extended-release naltrexone. The mean gestational age at study enrollment was 21.7 (SD, 12) weeks. Of the 7 participants, there was no return to nonprescribed opioid use and 2 who experienced a return to alcohol use over the course of the study. All individuals delivered vaginally at a mean of 37 weeks gestation without any peripartum pain difficulties. Five of the individuals (71.4%) remained on naltrexone 12 months after delivery. There were no reported fetal anomalies and one preterm delivery. None of the infants developed neonatal opioid withdrawal syndrome.

CONCLUSIONS

For pregnant individuals with OUD or AUD treated with naltrexone, there were low rates of return to nonprescribed use and reassuring pregnant person and infant outcomes to 12 months postpartum.

Naltrexone Compared With Buprenorphine or Methadone in Pregnancy: A Systematic Review

OBJECTIVE

Although naltrexone is an evidence-based medication for opioid use disorder (MOUD), few data are available with use in pregnancy. Our objective was to assess outcomes of pregnant individuals with opioid use disorder (OUD) taking naltrexone compared with those taking methadone or buprenorphine.

DATA SOURCES

We undertook a systematic review using electronic database search (PubMed, CINAHL, EMBASE, PsycInfo), conference proceedings, and trial registries including ClinicalTrials.gov .

METHODS OF STUDY SELECTION

We conducted an electronic search of research articles through May 2023 for randomized controlled trials, prospective cohort, and retrospective cohort studies of naltrexone (oral, implant, or extended release) compared with methadone or buprenorphine (sublingual or extended release) among pregnant individuals with OUD. After double review of all articles, we abstracted obstetric (primary outcome: gestational age at delivery), neonatal (primary outcome: neonatal abstinence syndrome [NAS]), and substance use outcomes.

TABULATION, INTEGRATION, AND RESULTS

Five studies met eligibility criteria; four were retrospective cohort studies, and one was a prospective cohort study. Four studies included data on gestational age at delivery (weeks) with no difference detected between the two groups in any study (mean difference ranging -0.20, 95% CI, -1.49-1.09 to 0.8, 95% CI, -0.15 to 1.75). Three studies included data on NAS with all studies detecting a lower risk in the naltrexone group compared with methadone or buprenorphine (relative risk ranging from 0.08, 95% CI, 0.01-1.16 to 0.15, 95% CI, 0.06-0.36). Most studies (four of five) had a moderate or high potential for selection bias primarily driven by small sample size and lack of controlling for confounders.

CONCLUSION

Although the evidence base is limited, available data suggest that naltrexone use in pregnancy is a reasonable MOUD option with reassuring perinatal outcomes. To enhance confidence in this conclusion and to assess substance use outcomes, further comparative studies of pregnant people with OUD taking naltrexone and other MOUD types are needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, 42017074249.

Multimodal Acute Pain Management in the Parturient with Opioid Use Disorder: A Review

The opioid epidemic in the United States has led to an increasing number of pregnant patients with opioid use disorder (OUD) presenting to obstetric units. Caring for this complex patient population requires an interdisciplinary approach involving obstetricians, anesthesiologists, addiction medicine physicians, psychiatrists, and social workers. The management of acute pain in the parturient with OUD can be challenging due to several factors, including respiratory depression, opioid tolerance, and opioid-induced hyperalgesia. Patients with a history of OUD can present in one of three categories: 1) those with untreated OUD; 2) those who are currently abstinent from opioids; 3) those being treated with medications to prevent withdrawal. A patient-centered, multimodal approach is essential for optimal peripartum pain relief and prevention of adverse maternal and neonatal outcomes. Medications for opioid use disorder (MOUD), previously referred to as medication-assisted therapy (MAT), include opioids like methadone, buprenorphine, and naltrexone. These are prescribed for pregnant patients with OUD, but appropriate dosing and administration of these medications are critical to avoid withdrawal in the mother. Non-opioid analgesics such as acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) can be used in a stepwise approach, and regional techniques like neuraxial anesthesia and truncal blocks offer opioid-sparing options. Other medications like ketamine, clonidine, dexmedetomidine, nitrous oxide, and gabapentinoids show promise for pain management but require further research. Overall, a comprehensive pain management strategy is essential to ensure the well-being of both the mother and the fetus in pregnant patients with OUD.

National Provider Survey: Use of Naltrexone for Pregnant Individuals with Substance Use Disorders

OBJECTIVES

A national survey evaluated the availability of naltrexone as a treatment for alcohol use disorder and/or opioid use disorder for pregnant individuals. Provider perceptions of barriers to treatment with naltrexone during pregnancy were also examined.

METHODS

Sites were selected from a national registry of naltrexone prescribers (N = 5208). A 10% sampling of sites within 150 miles of each state's capital was selected (n = 2073). Survey of 11 questions included availability of naltrexone for pregnant individuals, standard practices for treating pregnant individuals already on naltrexone, and barriers to treatment. Survey responses were summarized to identify top barriers and national trends in service availability.

RESULTS

Of the 236 sites contacted, 78 (33.1%) completed the survey. There was significant geographic variation in number of available sites, with Northeast United States having the most sites. Of the 78 responding sites, only 23 (35.9%) offered naltrexone for pregnant individuals. The most common barriers to prescribing naltrexone included the following: sites without pregnant patients (15.6%), lack of national guidelines in using naltrexone for pregnant patients (14.1%), providers' discomfort with prescribing naltrexone during pregnancy due to safety concerns (9.4%), and providers' discomfort due to inexperience (4.7%).

CONCLUSIONS

Accessibility of naltrexone and related care for pregnant individuals with alcohol use disorder and opioid use disorder varies greatly across the United States with numerous barriers and educational gaps identified. Additional research and resources are needed to expand naltrexone treatment access for pregnant individuals.

Guideline No. 443b: Opioid Use Throughout Women's Lifespan: Opioid Use in Pregnancy and Breastfeeding

OBJECTIVE

To provide health care providers the best evidence on opioid use and women's health. Areas of focus include pregnancy and postpartum care.

TARGET POPULATION

The target population includes all women currently using or contemplating using opioids.

OUTCOMES

Open, evidence-informed dialogue about opioid use will improve patient care.

BENEFITS, HARMS, AND COSTS

Exploring opioid use through a trauma-informed approach provides the health care provider and patient with an opportunity to build a strong, collaborative, and therapeutic alliance. This alliance empowers women to make informed choices about their own care. It also allows for the diagnosis and possible treatment of opioid use disorders. Opioid use should not be stigmatized, as stigma leads to poor "partnered care" (i.e., the partnership between the patient and care provider). Health care providers need to understand the effect opioids can have on pregnant women and support them to make knowledgeable decisions about their health.

EVIDENCE

A literature search was designed and carried out in PubMed and the Cochrane Library databases from August 2018 until March 2023 using following MeSH terms and keywords (and variants): opioids, opioid agonist therapy, illicit drugs, fertility, pregnancy, fetal development, neonatal abstinence syndrome, and breastfeeding.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

All health care providers who care for pregnant and/or post-partum women and their newborns.

TWEETABLE ABSTRACT

Opioid use during pregnancy often co-occurs with mental health issues and is associated with adverse maternal, fetal, and neonatal outcomes; treatment of opioid use disorder with agonist therapy for pregnant women can be safe during pregnancy where the risks outnumber the benefits.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Directive clinique no 443b : Opioïdes aux différentes étapes de la vie des femmes : Grossesse et allaitement

OBJECTIF

Présenter aux professionnels de la santé les données probantes concernant l'utilisation des opioïdes et la santé des femmes. Les domaines d'intérêt sont la grossesse et les soins post-partum.

POPULATION CIBLE

Toutes les femmes qui utilisent des opioïdes. RéSULTATS: Un dialogue ouvert et éclairé sur l'utilisation des opioïdes améliorera les soins aux patientes. BéNéFICES, RISQUES ET COûTS: L'exploration de l'utilisation d'opioïdes par une approche tenant compte des traumatismes antérieurs donne au professionnel de la santé et à la patiente l'occasion de bâtir une alliance solide, collaborative et thérapeutique. Cette alliance permet aux femmes de faire des choix éclairés. Elle favorise le diagnostic et le traitement possible du trouble lié à l'utilisation d'opioïdes. L'utilisation ne doit pas être stigmatisée, puisque la stigmatisation affaiblit le partenariat (le partenariat entre patiente et professionnel de la santé). Les professionnels de la santé ceus-ci doivent comprendre l'effet potentiel des opioïdes sur la santé les femmes enceintes et les aider à prendre des décisions éclairées sur leur santé. DONNéES PROBANTES: Une recherche a été conçue puis effectuée dans les bases de données PubMed et Cochrane Library pour la période d'août 2018 à mars 2023 des termes MeSH et mots clés suivants (et variantes) : opioids, opioid agonist therapy, illicit drugs, fertility, pregnancy, fetal development, neonatal abstinence syndrome et breastfeeding. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). PROFESSIONNELS CONCERNéS: Tous les professionnels de la santé qui prodiguent des soins aux femmes et aux nouveaux-nés. RéSUMé POUR TWITTER: La consommation d'opioïdes pendant la grossesse coïncide souvent avec des problèmes de santé mentale et est associée à des conséquences néfastes pour la mère, le fœtus et le nouveau-né ; le traitement des troubles liés à la consommation d'opioïdes par agonistes peut être sûr pendant la grossesse lorsque les risques sont plus nombreux que les avantages. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Interventions to Support Engagement in Addiction Care Postpartum: Principles and Pitfalls

There is a fundamental disconnect between the optimal management of addiction in general and care delivery in pregnancy and postpartum. Addiction is a chronic condition requiring some degree of management across the life course. Yet, in the US, reproductive care is episodic and centers more on pregnancy than at other stages of the reproductive life course. Pregnancy is prioritized in access to insurance as almost all pregnant people are Medicaid eligible but access ends at varying points postpartum. This results in a structural mismatch: the episodic management of the chronic condition of addiction only within gestational periods. Though people with substance use disorder (SUD) may access care in pregnancy, treatment attrition is common postpartum. Postpartum is a time of increased vulnerabilities where insurance churn and newborn caretaking responsibilities collide in a context of care withdrawal from the health system and health providers. In part in consequence, return to use, SUD recurrence, overdose, and overdose death are more common postpartum than in pregnancy, and drug deaths have become a leading cause of maternal deaths in the US. This review addresses interventions to support engagement in addiction care postpartum. We begin with a scoping review of model programs and evidence-informed interventions that have been shown to increase continuation of care postpartum. We then explore the realities of contemporary care through a review of clinical and ethical principles, with particular attention to harm reduction. We conclude with suggestions of strategies (clinical, research, and policy) to improve care postpartum and highlight potential pitfalls in the uptake of evidence-based and person-centered services.

Opioids and Opioid Use Disorder in Pregnancy

Overdose is a leading cause of pregnancy-associated morbidity and mortality in the United States. As such, all obstetric providers have a responsibility to provide evidence-based care for patients with opioid use disorder to mitigate adverse outcomes associated with substance use during pregnancy.

Pain Management After Cesarean Delivery Among Women with Opioid Use Disorder: Results from a Retrospective Pregnancy Cohort in a Rural Region of the Midwest

Background

Increasing numbers of pregnant women are being treated with buprenorphine for opioid use disorder (OUD), which can interfere with effectiveness of other opioids used for pain relief, making perioperative guidance for patients requiring cesarean delivery unclear.

Methods

Using a retrospective cohort design, we abstracted 8 years of medical records (2013-2020) from a hospital in rural Michigan. We compared analgesic use (as a proxy for pain) and hospital length of stay (LOS) between groups of women with OUD whose buprenorphine treatment was (1) discontinued before cesarean delivery (discontinuation) versus (2) continued throughout the perioperative period (maintenance). We used t-tests and Fisher's Exact tests for comparison of continuous and categorical variables, respectively.

Results

Maternal characteristics reflected the local population (87% non-Hispanic White; 9% American Indian). Of 12,179 mothers giving birth during the study timeframe, 87 met all inclusion criteria (2.4% with diagnosed OUD; 38% of those delivered by cesarean; 76% of those received prenatal buprenorphine treatment). Using the first 2 days of the hospital stay as the standard time window for comparison, there were no differences in perioperative opioid analgesic use (mean ± standard deviation [SD] = 141.6 ± 205.4 vs. 134.0 ± 136.3 morphine milligram equivalents, p = 0.89) or LOS (mean ± SD = 2.9 ± 0.9 vs. 3.3 ± 1.0 days, p = 0.14) between discontinuation (n = 17) versus maintenance (n = 70). There was a lower use of acetaminophen in the discontinuation group (mean ± SD = 3,842.6 ± 2,108.1 vs. 4,938.2 ± 2,008.4 mg, p = 0.0489).

Conclusion

This study provides empirical evidence supporting continued buprenorphine treatment for women with OUD throughout the perioperative period of a cesarean delivery in a rural setting, although replication with larger sample sizes would provide more confidence in the results.

Buprenorphine-naloxone versus Buprenorphine for Treatment of Opioid Use Disorder in Pregnancy

OBJECTIVES

Data regarding treatment outcomes with the use of buprenorphine-naloxone (BUP-NX) in pregnancy are scarce. The objective of this study is to examine the outcomes in a cohort of pregnancies treated with BUP-NX versus buprenorphine (BUP).

METHODS

This single-center, retrospective cohort study examined birthing person-infant dyads treated with BUP-NX versus BUP. The primary birthing person outcome was return to opioid use in pregnancy. The primary neonatal outcome was the need for pharmacologic treatment for neonatal opioid withdrawal syndrome (NOWS).

RESULTS

The BUP-NX and the BUP treatment groups included 33 and 73 dyads, respectively. Except for psychiatric medication use, all demographics were similar between groups. In the final regression models, neither the birthing person nor the neonatal outcomes differed. The adjusted odds ratio for return to use during pregnancy for the BUP-NX versus BUP groups was 1.93 (95% confidence interval, 0.78-4.76). The adjusted odds ratio for pharmacologic treatment of NOWS for the BUP-NX versus BUP groups was 0.65 (95% confidence interval, 0.27-1.54). Among a subgroup of persons who transitioned from BUP to BUP-NX mid-pregnancy, there was no proximate return to use or need for dose increase.

CONCLUSIONS

Compared with BUP, the use of BUP-NX in pregnancy is not associated with a higher risk of return to opioid use or a higher need for pharmacological treatment for NOWS.

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.

Medication for Addiction Treatment and Postpartum Health Care Utilization Among Pregnant Persons With Opioid Use Disorder

OBJECTIVE

To estimate treatment and postpartum health care utilization among pregnant persons with opioid use disorder (OUD) in Vermont and Maine.

METHODS

Vermont's and Maine's All Payer Claims Databases were used to identify deliveries 2010 to 2018 that were paid for, in part, by Medicaid. OUD was identified among pregnant persons if they had any claim with an OUD-diagnosis code (ICD-9/10) or medication for addiction treatment (MAT) code during the 5 months before delivery event. Consistent and inconsistent MAT were compared to no MAT on the rate of hospitalizations and emergency department (ED) visits in the first 12 months' postpartum using negative binomial regression.

RESULTS

From 2010 through 2018, 27,652 deliveries in Vermont and 43,480 deliveries in Maine were among persons insured by Medicaid. The prevalence of OUD among pregnant persons increased from 6.7% to 11.6% in Vermont and from 7.4% to 11.0% in Maine. Among pregnant persons with OUD in 2018, 57% had consistent MAT in Vermont and 50% had consistent MAT in Maine; approximately 32% and 27% were not in treatment in Vermont and Maine, respectively. In Maine, consistent MAT was associated with a 47% lower rate of hospitalization and 37% to 46% lower rates of ED visits when compared to those without MAT; in Vermont, those with consistent buprenorphine treatment had a 30% lower rate of ED visits.

CONCLUSIONS

Medicaid data from Vermont and Maine suggests that medication for addiction treatment for opioid use disorder during pregnancy reduces emergency health care utilization in the first year postpartum.

Low barrier perinatal psychiatric care for patients with substance use disorder: meeting patients across the perinatal continuum where they are

Pregnant and postpartum patients with substance use disorders (SUD) often have other co-occurring mental health disorders. Complications of substance use and mental health conditions, such as overdose and suicide, are a significant contributor to maternal morbidity and mortality. For individuals dually diagnosed with SUD and other mental health disorders, the perinatal period can be both a motivating and a vulnerable period for care. Barriers to optimal care include, but are not limited to, lack of screening, lack of referrals for care, a limited number of psychiatric providers available to care for pregnant patients, and stigma around mental health and addiction care in pregnancy. In this review, we discuss approaches to low-barrier perinatal psychiatric care for women with SUD to promote engagement in care. We review (1) appropriate psychiatric assessment and diagnostic work-up; (2) treatment planning incorporating shared-decision making, non-punitive and culturally sensitive patient-centred care, and principles of harm reduction with a focus on psychopharmacology, and (3) the benefits of an integrated and collaborative multidisciplinary care model for this subpopulation of vulnerable patients.

Endogenous opiates and behavior: 2019

This paper is the forty-second consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2019 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Integrated Review of the Assessment of Newborns With Neonatal Abstinence Syndrome

OBJECTIVE

To critically review and summarize current knowledge regarding the assessment of newborns with neonatal abstinence syndrome (NAS).

DATA SOURCES

We searched the following databases for articles on the assessment of newborns with NAS that were published in English between January 2014 and June 2020: PubMed, CINAHL, and PsycINFO. Keywords and Medical Subject Heading terms used to identify relevant research articles included neonatal abstinence syndrome; Finnegan Scale; eat, sleep, console; epigenetics; genetics; pharmacokinetics; and measurement. We independently reviewed articles for inclusion.

STUDY SELECTION

We retrieved 435 articles through database searches and 17 through manual reference searches; 31 articles are included in the final review. Excluded articles were duplicates, not relevant to NAS, qualitative studies, and/or of low quality.

DATA EXTRACTION

We used the methodology of Whittemore and Knafl to guide this integrative review. We extracted and organized data under the following headings: author, year and country, purpose, study design, participants, measurement, biomarker (if applicable), results, limitations, recommendations, and intervention.

DATA SYNTHESIS

The Finnegan Neonatal Abstinence Scale is the most widely used instrument to measure symptoms of NAS in newborns, although it is very subjective. Recently, there has been a transition from the Finnegan Neonatal Abstinence Scale to the eat, sleep, console method, which consists of structured assessment and intervention and has been shown to decrease length of hospital stay and total opioid treatment dose. Researchers examined biomarkers of NAS, including genetic markers and autonomic nervous system responses, on the variation in incidence and differential severity of NAS. In the included articles, women with opioid use disorder who were treated with naltrexone during pregnancy gave birth to newborns without NAS diagnoses. However, most women who were treated with buprenorphine gave birth to newborns with NAS diagnoses.

CONCLUSION

NAS negatively affects newborns in a multitude of ways, and the objective assessment and measurement of the newborn's response to withdrawal remains understudied and needs further investigation.

Pharmacotherapies for the Treatment of Alcohol Use Disorders During Pregnancy: Time to Reconsider?

It is generally recommended that medications only be used in pregnancy where the potential harms to both the mother and foetus are outweighed by the potential benefits. Despite the known harms associated with alcohol consumption during pregnancy, the use of medication for the treatment of pregnant women with an alcohol use disorder (AUD) appears to be rare. This is likely due to the lack of available data regarding the safety of these medications in pregnancy. We reviewed the literature and weighed up the harms associated with alcohol use and AUD during pregnancy with the potential benefits of medications for AUD in pregnancy, including acamprosate, naltrexone and disulfiram. There is little published evidence to support the safety of medications for AUD in pregnancy. However, from the research available it is likely that only disulfiram has the potential to cause serious foetal harm. While further research is required, acamprosate and naltrexone do not appear to be associated with substantial risks of congenital malformations or other serious consequences. Given the potential risks associated with alcohol consumption during pregnancy, the use of acamprosate and naltrexone should be considered for the treatment of pregnant women with AUD based on the current evidence base, although more research is warranted.

Neonatal Opioid Withdrawal Syndrome (NOWS): A Transgenerational Echo of the Opioid Crisis

The incidence of neonatal opioid withdrawal syndrome (NOWS) has increased substantially in the setting of the opioid epidemic, a major public health problem in the United States. At present, NOWS has commonly used assessment and treatment protocols, but new protocols have questioned old practices. However, because of limited access to opioid use disorder (OUD) treatment and socioeconomic factors, many pregnant (and postpartum) women with OUD do not receive treatment. The pathophysiology of NOWS is not completely understood, although limited research studies have been conducted in humans and animals to better understand its etiology. Moreover, there is evidence that epigenetic and genetic factors play a role in the development of NOWS, but further study is needed. Animal models have suggested that there are deleterious effects of in utero opioid exposure later in life. Clinical research has revealed the harmful long-term sequelae of NOWS, with respect to cognitive function and childhood development. Many psychiatric disorders begin during adolescence, so as infants born with NOWS approach adolescence, additional clinical and molecular studies are warranted to identify biologic and psychosocial risk factors and long-term effects of NOWS. Additionally, access to specialized OUD treatment for pregnant women must be more readily available in the United States, especially in rural areas.

The MATernaL and Infant NetworK to Understand Outcomes Associated with Treatment of Opioid Use Disorder During Pregnancy (MAT-LINK): Surveillance Opportunity

Pregnant women with opioid use disorder (OUD) are at risk of overdose, infectious diseases, and inadequate prenatal care. Additional risks include adverse pregnancy and infant outcomes, such as preterm birth and neonatal abstinence syndrome. Management and treatment of OUD during pregnancy are associated with improved maternal and infant outcomes. Professional organizations, including the American College of Obstetricians and Gynecologists, recommend offering opioid agonist pharmacotherapy (i.e., methadone or buprenorphine) combined with behavioral therapy as standard treatment for pregnant women with OUD. Other medications and herbal supplements have also been used by pregnant women for OUD. Determining which OUD treatments optimize maternal and infant outcomes is challenging given the host of potential factors that affect these outcomes. The Centers for Disease Control and Prevention initiated the MATernaL and Infant NetworK to Understand Outcomes Associated with Treatment of Opioid Use Disorder during Pregnancy (MAT-LINK) to monitor more than 2000 mothers and their infants, using data collected from geographically diverse clinical sites. Information learned from MAT-LINK will inform the future management and treatment of pregnant women with OUD.

Biased Opioid Antagonists as Modulators of Opioid Dependence: Opportunities to Improve Pain Therapy and Opioid Use Management

Opioid analgesics are effective pain therapeutics but they cause various adverse effects and addiction. For safer pain therapy, biased opioid agonists selectively target distinct μ opioid receptor (MOR) conformations, while the potential of biased opioid antagonists has been neglected. Agonists convert a dormant receptor form (MOR-μ) to a ligand-free active form (MOR-μ*), which mediates MOR signaling. Moreover, MOR-μ converts spontaneously to MOR-μ* (basal signaling). Persistent upregulation of MOR-μ* has been invoked as a hallmark of opioid dependence. Contrasting interactions with both MOR-μ and MOR-μ* can account for distinct pharmacological characteristics of inverse agonists (naltrexone), neutral antagonists (6β-naltrexol), and mixed opioid agonist-antagonists (buprenorphine). Upon binding to MOR-μ*, naltrexone but not 6β-naltrexol suppresses MOR-μ*signaling. Naltrexone blocks opioid analgesia non-competitively at MOR-μ*with high potency, whereas 6β-naltrexol must compete with agonists at MOR-μ, accounting for ~100-fold lower in vivo potency. Buprenorphine's bell-shaped dose-response curve may also result from opposing effects on MOR-μ and MOR-μ*. In contrast, we find that 6β-naltrexol potently prevents dependence, below doses affecting analgesia or causing withdrawal, possibly binding to MOR conformations relevant to opioid dependence. We propose that 6β-naltrexol is a biased opioid antagonist modulating opioid dependence at low doses, opening novel avenues for opioid pain therapy and use management.