Buprenorphine versus Methadone for Opioid Use Disorder in Pregnancy.

BACKGROUND: Opioid agonist therapy is strongly recommended for pregnant persons with opioid use disorder. Buprenorphine may be associated with more favorable neonatal and maternal outcomes than methadone, but existing data are limited. METHODS: We conducted a cohort study involving pregnant persons who were enrolled in public insurance programs in the United States during the period from 2000 through 2018 in which we examined outcomes among those who received buprenorphine as compared with those who received methadone. Exposure to the two medications was assessed in early pregnancy (through gestational week 19), late pregnancy (gestational week 20 through the day before delivery), and the 30 days before delivery. Risk ratios for neonatal and maternal outcomes were adjusted for confounders with the use of propensity-score overlap weights. RESULTS: The data source for the study consisted of 2,548,372 pregnancies that ended in live births. In early pregnancy, 10,704 pregnant persons were exposed to buprenorphine and 4387 to methadone. In late pregnancy, 11,272 were exposed to buprenorphine and 5056 to methadone (9976 and 4597, respectively, in the 30 days before delivery). Neonatal abstinence syndrome occurred in 52.0% of the infants who were exposed to buprenorphine in the 30 days before delivery as compared with 69.2% of those exposed to methadone (adjusted relative risk, 0.73; 95% confidence interval [CI], 0.71 to 0.75). Preterm birth occurred in 14.4% of infants exposed to buprenorphine in early pregnancy and in 24.9% of those exposed to methadone (adjusted relative risk, 0.58; 95% CI, 0.53 to 0.62); small size for gestational age in 12.1% and 15.3%, respectively (adjusted relative risk, 0.72; 95% CI, 0.66 to 0.80); and low birth weight in 8.3% and 14.9% (adjusted relative risk, 0.56; 95% CI, 0.50 to 0.63). Delivery by cesarean section occurred in 33.6% of pregnant persons exposed to buprenorphine in early pregnancy and 33.1% of those exposed to methadone (adjusted relative risk, 1.02; 95% CI, 0.97 to 1.08), and severe maternal complications developed in 3.3% and 3.5%, respectively (adjusted relative risk, 0.91; 95% CI, 0.74 to 1.13). Results of exposure in late pregnancy were consistent with results of exposure in early pregnancy. CONCLUSIONS: The use of buprenorphine in pregnancy was associated with a lower risk of adverse neonatal outcomes than methadone use; however, the risk of adverse maternal outcomes was similar among persons who received buprenorphine and those who received methadone. (Funded by the National Institute on Drug Abuse.).

Children had increased risks of impaired motor and visual-motor skills after prenatal exposure to opioid maintenance therapy.

AIM: Preschool children prenatally exposed to opioid maintenance therapy (OMT) have an increased risk of neurodevelopmental impairments. We aimed to investigate long-term motor and visual-motor integration outcome in children aged 5-13 Years, born to mothers in OMT. METHODS: From January 2018 to June 2021, 63 children prenatally exposed to OMT and 63 comparison children matched for age and gender, were examined at two Norwegian hospitals. Motor skills were assessed by the Movement-ABC test and visual-motor integration by the Beery VMI test. A motor function neurological assessment test was used to examine neuromotor soft signs. RESULTS: In the OMT-exposed group, 16% had motor impairment, 35% had motor problems and 19% had visual-motor integration problems. Forty-three percent of the exposed children had neuromotor soft signs. Strabismus had some influence on motor and visual-motor outcomes but could not explain the group differences. CONCLUSION: Children prenatally exposed to opioid maintenance therapy have an increased risk of long-term motor impairment and visual-motor problems. In addition, they exhibit significantly more neuromotor soft signs, which may affect general well-being, leisure activities and school performance.

Intrauterine exposure to maternal opioid maintenance treatment and associated risk factors may impair child growth.

AIM: How maternal opioid maintenance treatment (OMT) affects children is under-researched. This population-based registry study investigated child growth and somatic health following intrauterine exposure to this treatment. METHODS: Children born between 1 March 2011 and 30 May 2021 to mothers who used buprenorphine, buprenorphine-naloxone, or methadone throughout their pregnancies were followed for 2 years at the Helsinki University Hospital, Finland. Appropriate statistical tests were used to compare the treatment groups. RESULTS: Of the 67 neonates, 52% were male, 96% were born full-term and 63% were treated for neonatal opioid withdrawal syndrome. Otherwise, the children were predominantly healthy, although relatively small: 22% were small for gestational age, the methadone group children being the smallest. Foetal exposure to maternal methadone treatment, illicit drugs, hepatitis C and smoking were associated with small for gestational age; the former two were also associated with later slower growth, especially head growth and weight gain (p < 0.001). However, 29% were overweight at 2 years. CONCLUSION: Using child growth as the outcome, we found that buprenorphine-naloxone and buprenorphine-monotherapy had equal effects as forms of maternal OMT. Exposure to multiple risk factors may harm foetal and subsequent growth. We recommend long-term follow-up of children exposed to maternal OMT.

Associations of methadone and buprenorphine-naloxone doses with unregulated opioid use, treatment retention, and adverse events in prescription-type opioid use disorders: Exploratory analyses of the OPTIMA study.

BACKGROUND AND OBJECTIVES: Buprenorphine/naloxone (BUP-NX) and methadone are used to treat opioid use disorder (OUD), yet there is insufficient evidence on the impact of doses on interventions' effectiveness and safety when treating OUD attributable to other opioids than heroin. METHODS: We explored associations between methadone and BUP-NX doses and treatment outcomes using data from OPTIMA, a 24-week, pragmatic, open-label, multicenter, pan-Canadian, randomized controlled, two-arm parallel trial with participants (N = 272) with OUD who primarily use opioids other than heroin. Participants were randomized to receive flexible take-home BUP-NX (n = 138) or standard supervised methadone treatment (n = 134). We examined associations between highest BUP-NX and methadone doses, and (1) percentage of opioid-positive urine drug screens (UDS); (2) retention in the assigned treatment; and (3) adverse events (AEs). RESULTS: The mean (SD) highest BUP-NX and methadone dose were 17.31 mg/day (8.59) and 67.70 mg/day (34.70). BUP-NX and methadone doses were not associated with opioid-positive UDS percentages or AEs. Methadone dose was associated with higher retention in treatment (odds ratio [OR]: 1.025; 95% confidence interval [CI]: 1.010; 1.041), while BUP-NX dose was not (OR: 1.055; 95% CI: 0.990; 1.124). Higher methadone doses (70-110 mg/day) offered higher odds of treatment retention. DISCUSSION AND CONCLUSION: Methadone dose was associated with higher retention, which may be related to its full µ-opioid receptor agonism. Future research should notably ascertain the effect of pace of titration on a wide range of outcomes. SCIENTIFIC SIGNIFICANCE: Our results extend previous findings of high doses of methadone increasing retention to be applied in our population using opioids other than heroin, including highly potent opioids.

Systematic review on the clinical management of chronic pain and comorbid opioid use disorder. / Revisión sistemática sobre el manejo clínico del dolor crónico y el trastorno por uso de opioides simultáneo.

The crisis caused by prescribed opioids and their related side effects are a public health problem worldwide. Most of these are prescribed for coping with chronic pain. The coexistence of opioid use disorder (OUD) in patients with chronic pain represents a complex challenge due to the need for managing both pain and OUD. The aim of this systematic review is to evaluate the efficacy of feasible treatments for this population with OUD and comorbid chronic pain for both conditions. A systematic database search has been performed using Cochrane Library, MEDLINE, PsycINFO and ClinicalTrials.gov in compliance with PRISMA guidelines. Eligible articles addressed the outcomes in chronic pain patients with comorbid opioid use disorder after treatment interventions were applied. Of 593 identified articles, nine were eligible for qualitative review (n = 7 pharmacological interventions; n = 2 psychological interventions). Methadone, buprenorphine, cognitive-behavioral and mindfulness showed promising results, but data were inconclusive (<2 RCT with low risk of bias). It is unclear whether the opioid agonist treatment should be maintained or tapered and which drug should be prescribed for the opioid substitution therapy (methadone or buprenorphine/naloxone). Mindfulness and cognitive behavioral therapy have a discrete effect on improving negative affect but not pain. The therapeutic approach might be individualized under a shared decision-making basis.

La crisis causada por los opioides recetados y sus efectos secundarios relacionados son un problema de salud pública en todo el mundo. La mayoría de estos medicamentos se recetan para el afrontamiento del dolor crónico. La coexistencia del trastorno por uso de opioides (TUO) en pacientes con dolor crónico representa un desafío complejo debido a la necesidad de controlar tanto el dolor como el TUO. El objetivo de esta revisión sistemática es evaluar la eficacia de los tratamientos posibles para dicha población con TUO y dolor crónico. Se ha realizado una revisión sistemática usando las bases de datos Cochrane Library, MEDLINE, PsycINFO y ClinicalTrials.gov, conforme a las pautas PRISMA. Los artículos elegibles abordaron los resultados en pacientes con dolor crónico y diagnóstico comórbido de TUO, después de aplicar una intervención. De 593 artículos identificados, nueve eran elegibles para la revisión cualitativa (n = 7 intervenciones farmacológicas; n = 2 intervenciones psicológicas). La metadona, la buprenorfina, la terapia cognitivo-conductual y el mindfulness mostraron resultados prometedores, pero los datos no eran concluyentes (<2 ECA con bajo riesgo de sesgo). No está claro si el tratamiento con agonistas opioides debe mantenerse o disminuirse y qué fármaco debe prescribirse para la terapia de sustitución de opioides (metadona o buprenorfina/naloxona). El mindfulness y la terapia cognitivo-conductual tienen un efecto discreto en la mejora del afecto negativo, pero no del dolor. El enfoque terapéutico podría individualizarse sobre la base de una toma de decisiones conjunta.

A genetic-based population PK/PD modeling of methadone in Chinese opiate dependence patients.

PURPOSE: The full potential of methadone maintenance treatment (MMT) is often limited by the large inter-individual variability in both pharmacokinetics (PK) and pharmacodynamics (PD), and by the risk of torsade de pointes, a severe adverse effect caused by QTc prolongation. The current study aims to quantitate the contribution of genetic polymorphisms and other variables in PK/PD variability, and their contribution to the QTc interval prolongation in Chinese MMT patients. METHODS: Population PK models were developed to fit (R)- and (S)-methadone PK data. Hierarchical models were tested to characterize the PK profile, the concentration-QTc relationship, and concentration-urinalysis illicit drug testing relationship, with demographics and genetic variants being included as covariates. Simulation based on the developed PK/PD models was performed to assess the effect of methadone dose and genetic variants on QTc interval prolongation. RESULTS: The PK data were best-fit by a one-compartment, first-order absorption model. Clearance of (R)- and (S)-methadone was both affected by the weighted activity score derived from genetic variants. A linear model was used to describe both the methadone concentration-urinalysis illicit drug testing relationship and the methadone concentration-QTc relationship. Concentration of (R)- and (S)-methadone exhibits a comparable effect on QTc prolongation. Simulation showed that the percentage of QTc higher than 450 ms was almost doubled in the lowest clearance group as compared the highest when methadone dose was greater than 120 mg. CONCLUSIONS: The large variability in PK/PD profiles can be partially explained by the genetic variants in an extent different from other population, which confirmed the necessity to conduct such a study in the specific Chinese patients.

A retrospective, observational study on medication for opioid use disorder during pregnancy and risk for neonatal abstinence syndrome.

OBJECTIVES: The prevalence of opioid use disorder (OUD) among pregnant women is increasing. Research consistently demonstrates the efficacy of medications for OUD (MOUD); however, researchers have called for additional studies evaluating the safety of MOUD during pregnancy, particularly the relative safety of two commonly used MOUD medications-methadone and buprenorphine. This study aimed to evaluate the consequences of MOUD exposure during pregnancy on risk for neonatal abstinence syndrome (NAS). METHODS: In a clinical sample of infants born to women with OUD, we evaluated the risk of NAS among those exposed to (i) methadone and (ii) buprenorphine compared with those unexposed to MOUD, as well as the risk of NAS among those exposed to (i) methadone compared with those exposed to (ii) buprenorphine. RESULTS: Compared with buprenorphine-exposed infants (n = 37), methadone-exposed infants (n = 27) were at increased risk for NAS (odds ratio [OR] = 4.67, 95% confidence interval [CI]: 1.03, 21.17). Compared with unexposed infants (n = 43), buprenorphine-exposed infants were at decreased risk for NAS (OR = 0.45, 95% CI: 0.14, 1.39) and methadone-exposed infants were at increased risk for NAS (OR = 2.64, 95% CI: 0.79, 8.76), though these associations were not statistically significant. CONCLUSIONS: Our study suggests that when methadone and buprenorphine are equally appropriate options for the treatment of OUD in pregnant women, buprenorphine may add the additional benefit of reduced risk of newborn NAS.

Medications for opioid use disorder (MOUD), such as buprenorphine and methadone, are effective in reducing the significant harms associated with untreated opioid use disorder (OUD) in nonpregnant and pregnant adults. While previous research clearly documents that the risks of MOUD in pregnancy are less than the risks of untreated OUD in pregnancy, researchers have called for additional studies evaluating the safety of MOUD during pregnancy, particularly the relative safety of methadone and buprenorphine. In a clinical sample of infants born to women with OUD, we showed that buprenorphine-exposed infants were at significantly reduced risk for neonatal abstinence syndrome compared with methadone-exposed infants. Our study adds to the growing body of evidence supporting the use of buprenorphine over methadone for the treatment of OUD among pregnant women.

Prenatal methadone exposure and child developmental outcomes in 2-year-old children.

AIM: To examine the developmental outcomes of children born to opioid-dependent females enrolled in methadone maintenance and identify pre- and postnatal factors that place these children at developmental risk. METHOD: Ninety-nine methadone-maintained females and their 100 infants (42 females, 58 males, mean gestational age 38.8wks) were recruited during pregnancy/at birth and studied to age 2 years alongside a regionally representative comparison group of 108 non-methadone-maintained females and their 110 infants (62 females, 48 males, mean gestational age 39.2wks). Information about perinatal exposure was collected from medical records, maternal urine and infant meconium toxicological analysis, maternal interviews (at birth and at 18mo), and a home visit (at 18mo). At age 2 years, child neuromotor function, cognition, language, and emotional/behavioral dysregulation were assessed. RESULTS: Opioid-exposed children achieved lower motor, cognitive, and language scores and had poorer self, emotional, eating/feeding, and sensory processing regulation than unexposed children. After adjustment for maternal education and other substance use in pregnancy, between-group differences in child motor, cognitive, and overall dysregulation remained. Postnatal parental and family factors explained a further 40% to 52% of between-group differences in child outcomes. INTERPRETATION: These children and families are extremely high-risk and need antenatal and postnatal support. Children exposed to opioids during pregnancy have pervasive developmental difficulties by age 2 years. These challenges are largely explained by adverse pregnancy and socio-environmental exposures, emphasizing the importance of specialist prenatal care and postnatal intervention support. What this paper adds Children born to opioid-dependent females are at high risk of pervasive developmental problems. These problems span a range of functional domains, including motor, cognitive, language, and behavioral/emotional dysregulation. Contributing factors include other adverse pregnancy exposures, postnatal environmental factors, and the direct effects of prenatal opioid exposure.

Thrombosis of the Renal Vein and Inferior Vena Cava Associated With Placental Fetal Vascular Malperfusion in a Neonate Exposed to Methadone Maintenance Therapy In Utero.

Methadone, an opioid agonist, is the recommended treatment for pregnant women with opioid use disorder (OUD). Fetal/neonatal autopsy findings as well as placental changes in the setting of maternal OUD or methadone maintenance therapy (MMT) are not well-characterized. Here we present a case of a neonate who had exposure to MMT while in utero and died shortly after birth and was subsequently found to have multifocal calcified renal vein thrombosis, a recent inferior vena cava thrombus, and placental features of fetal vascular malperfusion at autopsy.

Treatments of Sexual Dysfunction in Opioid Substitution Therapy Patients: A Systematic Review and Meta-Analysis.

Sexual dysfunction is a common condition in the opioid substitution therapy (OST) population. We aimed to determine the efficacy and safety of treatment for sexual dysfunction in the OST population. We searched for interventional studies from Medline, PubMed, and Scopus. Three independent authors conducted a risk-of-bias assessment (RoB 2). A total of seven studies (five randomized-controlled trials, two quasi-experimental), including 473 patients with sexual dysfunction, were identified. Among these, three bupropion (n=207), one trazodone (n=75), two rosa Damascena (n=100), and one ginseng (n=91) studies had reported significantly improve various sexual functioning domains in both genders. In a meta-analysis, bupropion significantly increased male sexual function with standardized mean difference of 0.53; 95% confidence interval of 0.19-0.88; P < 0.01; I2=0. The adverse effects were minor for all agents, and no significant difference between treatment and placebo groups in randomized-controlled trials. These agents have a promising future as therapy for sexual dysfunction in the OST population. However, given the limited sample size and number of studies, further studies should be conducted to confirm the use of these agents.

Factors Associated with Low Bone Density in Opioid Substitution Therapy Patients: A Systematic Review.

Background: Long-term opioid therapy is a risk factor for low bone mineral density (BMD). However, other factors may also contribute to low BMD. Several studies have examined the variables that might contribute to low BMD in patients receiving opioid replacement therapy (OST). However, to our knowledge, there was no systemic review conducted to address this particular issue. Thus, we reviewed the articles on the factors associated with low BMD in the population of opioid use disorder receiving substitution therapy. Methods: The articles that examined correlates or risk factors of low BMD in OST population were retrieved from OVID, SCOPUS, and PUBMED from inception until July 2020 by two independent investigators. Results: A total of 429 articles from three databases were retrieved initially. After screening based on eligibility criteria, five articles were included in the final analysis. The risk factors or correlates found to be significantly associated with low BMD in the OST population include male gender, low body mass index, low testosterone level, methadone or heroin use, and longer duration of heavy alcohol use. The review limitations include small sample sizes and inconsistent definition of variables. Conclusion: OST patients should be screened for BMD and its associated factors. Guidelines and training of practitioners involving in the OST service should be provided to increase the detection of low BMD in the OST population.

Salivary cortisol levels relate to cognitive performance in children prenatally exposed to methadone or buprenorphine.

Opioid maintenance therapy (OMT) is generally recommended for pregnant opioid-dependent women. However, much is still unknown about the potential long-term effects of prenatal methadone and buprenorphine exposure. This study explored the long-term effects of prenatal methadone and buprenorphine exposure in a cohort (n = 41) of children, aged 9-11 years, using the Wechsler Abbreviated Scale of Intelligence (WASI) to measure cognitive development and salivary cortisol samples to measure HPA-axis activity. Prenatally exposed children scored significantly lower on all four subtests of WASI (vocabulary, similarities, block design, and matrix reasoning), compared to a comparison group (all p < .05). No group differences were found for salivary cortisol levels or cortisol reactivity levels (all p > .05). Cortisol levels significantly predicted matrix reasoning scores for the OMT group, ß = -65.58, t(20) = 15.70, p = .02. Findings suggest that prenatal exposure to methadone or buprenorphine does not have long-term effects on children's HPA-axis functioning. However, since children of women in OMT scored significantly lower on tasks of cognitive function, careful follow-up throughout the school years and across adolescence is recommended.

Fetal Outcomes with Detoxification from Opioid Drugs during Pregnancy: A Systematic Review.

OBJECTIVE: This study aimed to perform a systematic review of all studies reporting fetal outcomes following detoxification or tapering of opioid drugs during pregnancy. STUDY DESIGN: PubMed, Scopus, Medline, and Google Scholar were searched, and only manuscripts clearly reporting pregnancy/fetal outcomes involving tapering or detoxification from opioid drugs were included. Only pregnancies managed after 1980 were included (when antenatal fetal surveillance became more routine). Collected data included study design, location, years patients were managed, number of patients who were tapered or detoxified, method of tapering, and pregnancy outcome. RESULTS: A total of 14 publications met the criteria for review after evaluating more than 2,000 abstracts and 153 published manuscripts. In 1,097 pregnancies, based on mortality rate analyses and forest plots, no increased fetal risks due to tapering or detoxification from opioid drugs were identified. No increased risk of preterm delivery was found. CONCLUSION: Pregnant women with opioid use disorder who are stable in a medication-assisted treatment program with behavioral health can be informed that tapering or full detoxification from opioid drugs does not increase the fetal risk of poor pregnancy outcome. Future research needs to answer the questions on maternal and long-term newborn consequences of tapering or detoxification versus long-term newborn consequences of continued chronic in utero opioid exposure.

Prevention of Neonatal Abstinence Syndrome in an Outpatient Prenatal Buprenorphine Tapering Program.

OBJECTIVES: Many addicted pregnant patients receiving buprenorphine medication-assisted therapy (MAT) wish to discontinue this medication while pregnant. This study was undertaken to determine whether outpatient detoxification from buprenorphine during pregnancy is safe and effective when confirmed with postdetoxification urine drug screens (UDSs). METHODS: This case series reports the maternal and neonatal outcomes for 21 patients who ended MAT with buprenorphine while pregnant. A retrospective chart review of both maternal and newborn electronic medical records was performed to obtain results. Newborn neonatal abstinence syndrome (NAS) diagnosis, need for morphine, maternal safety and fetal/newborn complications were assessed. Maternal sobriety was documented with UDSs at the time of admission for delivery. Umbilical cord blood also was assessed for substances of abuse. An additional 182 pregnant women who lowered their buprenorphine doses but did not decide to end MAT were assessed via routine quality assurance methods. RESULTS: None of the women who stopped buprenorphine during their pregnancy as confirmed by UDSs and umbilical cord sampling delivered neonates who had NAS. Eleven patients ended MAT with medical assistance and 10 ended MAT without medical assistance. No overdoses were reported for the 182 additional pregnant patients who indicated an intention to taper buprenorphine dosage while pregnant but who did not decide to end MAT; the neonatal benefits were obtained without any identified maternal harm. CONCLUSIONS: The neonates of pregnant women enrolled in an outpatient buprenorphine MAT tapering program who are able to completely stop taking buprenorphine (as documented by negative urinary drug screen) are very unlikely to have NAS. Further research will be important.

Opioid-related treatment, interventions, and outcomes among incarcerated persons: A systematic review.

BACKGROUND: Worldwide opioid-related overdose has become a major public health crisis. People with opioid use disorder (OUD) are overrepresented in the criminal justice system and at higher risk for opioid-related mortality. However, correctional facilities frequently adopt an abstinence-only approach, seldom offering the gold standard opioid agonist treatment (OAT) to incarcerated persons with OUD. In an attempt to inform adequate management of OUD among incarcerated persons, we conducted a systematic review of opioid-related interventions delivered before, during, and after incarceration. METHODS AND FINDINGS: We systematically reviewed 8 electronic databases for original, peer-reviewed literature published between January 2008 and October 2019. Our review included studies conducted among adult participants with OUD who were incarcerated or recently released into the community (≤90 days post-incarceration). The search identified 2,356 articles, 46 of which met the inclusion criteria based on assessments by 2 independent reviewers. Thirty studies were conducted in North America, 9 in Europe, and 7 in Asia/Oceania. The systematic review included 22 randomized control trials (RCTs), 3 non-randomized clinical trials, and 21 observational studies. Eight observational studies utilized administrative data and included large sample sizes (median of 10,419 [range 2273-131,472] participants), and 13 observational studies utilized primary data, with a median of 140 (range 27-960) participants. RCTs and non-randomized clinical trials included a median of 198 (range 15-1,557) and 44 (range 27-382) participants, respectively. Twelve studies included only men, 1 study included only women, and in the remaining 33 studies, the percentage of women was below 30%. The majority of study participants were middle-aged adults (36-55 years). Participants treated at a correctional facility with methadone maintenance treatment (MMT) or buprenorphine (BPN)/naloxone (NLX) had lower rates of illicit opioid use, had higher adherence to OUD treatment, were less likely to be re-incarcerated, and were more likely to be working 1 year post-incarceration. Participants who received MMT or BPN/NLX while incarcerated had fewer nonfatal overdoses and lower mortality. The main limitation of our systematic review is the high heterogeneity of studies (different designs, settings, populations, treatments, and outcomes), precluding a meta-analysis. Other study limitations include the insufficient data about incarcerated women with OUD, and the lack of information about incarcerated populations with OUD who are not included in published research. CONCLUSIONS: In this carefully conducted systematic review, we found that correctional facilities should scale up OAT among incarcerated persons with OUD. The strategy is likely to decrease opioid-related overdose and mortality, reduce opioid use and other risky behaviors during and after incarceration, and improve retention in addiction treatment after prison release. Immediate OAT after prison release and additional preventive strategies such as the distribution of NLX kits to at-risk individuals upon release greatly decrease the occurrence of opioid-related overdose and mortality. In an effort to mitigate the impact of the opioid-related overdose crisis, it is crucial to scale up OAT and opioid-related overdose prevention strategies (e.g., NLX) within a continuum of treatment before, during, and after incarceration.

Methadone dosing strategies in preterm neonates can be simplified.

AIMS: A dramatic increase in newborn infants with neonatal abstinence syndrome has been observed and these neonates are frequently treated with complex methadone dosing schemes to control their withdrawal symptoms. Despite its abundant use, hardly any data on the pharmacokinetics (PK) of methadone is available in preterm neonates. Therefore we investigated developmental PK of methadone and evaluated current dosing strategies and possible simplification in this vulnerable population. METHODS: A single-centre open-label prospective study was performed to collect PK data after a single oral dose of methadone in preterm neonates. A population PK model was built to characterize developmental PK of (R)- and (S)-methadone. Model-based simulations were performed to identify a simplified dosing strategy to reach and maintain target methadone exposure. RESULTS: A total of 121 methadone concentrations were collected from 31 preterm neonates. A one-compartment model with first order absorption and elimination kinetics best described PK data for (R)- and (S)-methadone. Clearance increases with advancing gestational age and differs between R- and S-enantiomer, being slightly higher for the former (0.244 vs 0.167 L/h). Preterm neonates reached target exposure after 48 hours with currently used dosing schedules. Output from simulations revealed that target exposures can be achieved with a simplified dosing strategy during the first 4 days of treatment. CONCLUSION: Methadone clearance in preterm neonates increases with advancing gestational age and its disposition is influenced by its chirality. Simulations that account for developmental PK changes indicate a shorter methadone dosing strategy can maintain target exposure to control withdrawal symptoms.

Review article: Effective management of opioid withdrawal symptoms: A gateway to opioid dependence treatment.

BACKGROUND AND OBJECTIVES: The opioid crisis has taken an immense toll in the United States. On average, five lives are lost to an opioid overdose every hour of the day; estimated costs associated with opioid misuse exceed $500 billion annually. Illicit opioid discontinuation is the first step in the treatment of opioid use disorder (OUD), and transition to an opioid agonist may initiate treatment. However, discontinuation to abstinence from either OUD directly or following agonist treatment results in severely distressing opioid withdrawal symptoms (OWS). METHODS: This review evaluated studies on the etiology, burden, and management of OWS. RESULTS: Noradrenergic hyperactivity generates many OWS. These OWS can cause patients to relapse during early opioid discontinuation. While agonist therapies are generally first-line for moderate or severe OUD and reduce OWS, prescribing restrictions can limit their availability. DISCUSSION AND CONCLUSIONS: Non-opioid medications to treat OWS provides a gateway into long-term treatment with naltrexone or psychosocial therapies. For opioid dependent patients without OUD, non-opioid treatments like α-2 adrenergic agonists can facilitate opioid tapering. SCIENTIFIC SIGNIFICANCE: For the millions who are physically dependent on opioids, new treatments for OWS can enhance recovery from OUD and prevent relapse. (© 2019 The Authors. The American Journal on Addictions Published by Wiley Periodicals, Inc.;XX:1-8).

Methadone-Related Delirium: Prevalence, Causes, and Outcomes.

Goals consist of determining 5-year prevalence and recurrence of methadone-related delirium (MRD), along with causes, treatments, and outcomes. Sample comprised 81 patients in methadone maintenance treatment. Criteria for MRD encompassed delirium with high methadone serum levels plus alleviation of delirium upon lowering methadone serum levels. MRD occurred in 14 cases who had 25 episodes. MRD precipitants included physician prescribing (i.e., excessive methadone or medications slowing methadone metabolism), drug misuse, and renal-fluid alterations. Social affiliation (housing with family, intimate partner) reduced MRD; employment increased MRD. Recovery occurred in 23/25 episodes of MRD; two episodes progressed to dementia. Obtaining serum methadone levels fostered prompt recognition.

Intravenous Misuse of Methadone, Buprenorphine and Buprenorphine-Naloxone in Patients Under Opioid Maintenance Treatment: A Cross-Sectional Multicentre Study.

BACKGROUND: The act of intravenous misuse is common in patients under opioid maintenance treatment (OMT), but information on associated factors is still limited. OBJECTIVES: To explore factors associated with (a) intravenous OMT misuse, (b) repeated misuse, (c) emergency room (ER) admission, (d) misuse of different OMT types and (e) concurrent benzodiazepine misuse. METHODS: We recruited 3,620 patients in 27 addiction units in Italy and collected data on the self-reported rate of intravenous injection of methadone (MET), buprenorphine (BUP), BUP-naloxone (NLX), OMT dosage and type, experience of and reason for misuse, concurrent intravenous benzodiazepine misuse, pattern of -misuse in relation to admission to the addiction unit and ER -admissions because of misuse. According to inclusion/exclusion criteria, 2,585 patients were included. RESULTS: Intravenous misuse of OMT substances was found in 28% of patients with no difference between OMT types and was associated with gender, age, type of previous opioid abuse and intravenous benzodiazepine misuse. Repeated OMT misuse was reported by 20% (i.e., 71% of misusers) of patients and was associated with positive OMT misuse experience and intravenous benzodiazepine misuse. Admission to the ER because of misuse complications was reported by 34% of patients, this outcome being associated with gender, employment, type of previous opioid abuse and intravenous benzodiazepine misuse. OMT dosage was lower than the recommended maintenance dosage. CONCLUSIONS: We offered new information on factors associated with intravenous OMT misuse, repeated misuse and ER admission in Italian patients under OMT. Our data indicate that BUP-NLX misuse is not different from that of BUP or MET. Choosing the more expensive BUP-NLX over MET will likely not lead to the expected reduction of the risk of injection misuse of the OMT. Instead of prescribing new and expensive OMT formulations, addiction unit physicians and medical personnel should better focus on patient's features that are associated with a higher likelihood of misuse. Care should be paid to concurrent benzodiazepine and OMT misuse.

Magnetocardiographic identification of prolonged fetal corrected QT interval in women receiving treatment for opioid use disorder.

AIM: Pregnant women undergoing treatment for opioid use disorder (OUD) may be exposed to multiple QT prolonging agents. We used magnetocardiography to measure fetal QT intervals in mothers with OUD on buprenorphine therapy. METHODS: Fetal and maternal magnetocardiography was performed in pregnant women receiving buprenorphine-assisted treatment (Disorder group); these were matched by gestational age to pregnant women who were opiate naïve (Reference group). Corrected QT intervals were determined using Bazett's formula and compared between groups. RESULTS: A total of eight women in the Disorder group matched to eight in the Reference group. Seven of the mothers (88%) in the Disorder group were smokers; there were no smokers in the Reference group. The average fetal corrected QT was significantly longer (P = 0.022) in the Disorder group than that in the Reference group (505 milliseconds [ms] ± 68.6 [standard deviation] vs 383 ms ± 70.3 [standard deviation]). CONCLUSION: Novel data from this small sample demonstrate prolongation of fetal corrected QT in women with OUD participating in buprenorphine assisted therapy. Additional investigation from a larger sample is needed to clarify if fetal buprenorphine and/or tobacco exposure is associated with changes in fetal QT which would warrant further prenatal and postnatal testing.