Novel Therapeutic and Program-Based Approaches to Opioid Use Disorders.

Opioid use disorder continues to drive overdose deaths in many countries, including the United States. Illicit fentanyl and its analogues have emerged as key contributors to the complications and mortality associated with opioid use disorder. Medications for opioid use disorder treatment, such as methadone and buprenorphine, are safe and substantially reduce opioid use, infectious complications, and mortality risk, but remain underutilized. Polysubstance use and emerging substances such as xylazine and designer benzodiazepines create additional treatment challenges. Recent clinical and policy innovations in treatment delivery, including telemedicine, bridge clinics, and expanded models for accessing methadone have the potential to increase access to life-saving care for people living with opioid use disorder.

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.).

Unique pharmacodynamic properties and low abuse liability of the µ-opioid receptor ligand (S)-methadone.

(R,S)-methadone ((R,S)-MTD) is a µ-opioid receptor (MOR) agonist comprised of (R)-MTD and (S)-MTD enantiomers. (S)-MTD is being developed as an antidepressant and is considered an N-methyl-D-aspartate receptor (NMDAR) antagonist. We compared the pharmacology of (R)-MTD and (S)-MTD and found they bind to MORs, but not NMDARs, and induce full analgesia. Unlike (R)-MTD, (S)-MTD was a weak reinforcer that failed to affect extracellular dopamine or induce locomotor stimulation. Furthermore, (S)-MTD antagonized motor and dopamine releasing effects of (R)-MTD. (S)-MTD acted as a partial agonist at MOR, with complete loss of efficacy at the MOR-galanin Gal1 receptor (Gal1R) heteromer, a key mediator of the dopaminergic effects of opioids. In sum, we report novel and unique pharmacodynamic properties of (S)-MTD that are relevant to its potential mechanism of action and therapeutic use. One-sentence summary: (S)-MTD, like (R)-MTD, binds to and activates MORs in vitro, but (S)-MTD antagonizes the MOR-Gal1R heteromer, decreasing its abuse liability.

Exploring substance misuse in a prison in Wales: a cross-sectional analysis.

BACKGROUND: Since 2015, the risks of dying due to drug-related causes are higher in prison than in the general population, with opiates and psychoactive substances being the most common substances recorded on death certificates in prison. Many individuals use drugs before entering the prison environment, it is not clear which individuals continue to use drugs while in prison. This study is a first step towards identifying characteristics of those who use drugs in prison, while exploring substances commonly used. METHODS: This retrospective cross-sectional analysis was performed on 299 men (mean age 38 years [SD 11]) in a long-stay UK prison in South Wales who participated in a research study exploring cardiometabolic risk in prison, in which substance misuse was included as a risk variable. All men aged 25 years or older with no previous diagnosis of cardiometabolic illness were eligible to participate. Data were collected between Oct 7 and Oct 23, 2019. Participants were asked details about their substance use before and since entering the prison. Mental wellbeing was assessed using the short Warwick Edinburgh Mental Wellbeing Score and low mental wellbeing calculated as 1 SD below the population mean score. To examine associations between characteristics (age groups, mental wellbeing, exposure to prison environment) and drug use, we used binary logistic regression (adjusted for characteristics such as age group, mental wellbeing, and exposure to prison environment ). FINDINGS: Overall, 195 (65%) of 299 participants reported a history of drug use before entering prison. Since entering prison 49 (16%) participants reported using drugs including methadone, and 24 (8%) reported using drugs excluding methadone. The next leading substances used in prison were spice (11 [4%] participants) and cannabis (six [2%] participants). All those who used drugs in prison had a history of drug use. Individuals more likely to continue using drugs in prison were aged 39 years and younger (adjusted odds ratio [aOR] 4·72, 95% CI 1·88-11·89; p=0·0009), with reported low mental wellbeing (3·38, 1·54-7·41; p=0·002), and had spent collectively more than 2·5 years in the prison environment (4·77, 2·09-10·91; p=0·0002). INTERPRETATION: This study, from a limited sample, describes the characteristics of those who use drugs in prison. Harm reduction interventions targeted to these individuals could reduce the risk of prison drug-related deaths. These findings should be interpreted with some caution, as this is a single site and may not reflect the wider UK prison environment. FUNDING: Public Health Wales.

Benefits and challenges experienced by participants on long-term methadone maintenance treatment in China: a qualitative study.

BACKGROUND: Methadone maintenance treatment (MMT) has been implemented in China for nearly two decades, with a significant decrease in the number of participants in recent years. However, there is a lack of comprehensive research focusing on the long-term effectiveness in the context of this decline, especially from the perspectives of MMT participants themselves. This study aims to address this gap by examining the benefits and challenges experienced by long-term MMT participants in China, to uncover potential causes of the decrease in participant numbers and to improve the effectiveness of the program. METHODS: We conducted semi-structured interviews with 21 long-term MMT participants (treatment duration ≥ 5 years) recruited through purposive sampling from 6 MMT clinics in the Guangdong Province, China, between December 2021 and August 2022. Thematic analysis was employed to analyze the transcribed interviews. Two analysts independently coded the data, and a third researcher double-coded 20% of transcripts to ensure intercoder reliability. RESULTS: Overall, participants corroborated the notable decline in MMT participants during their long-term MMT, citing death, arrest, and self-perceived abstinence from heroin, as their perceived driving factors. They reported positive changes in their health, family relationships, and social functioning. However, they identified economic hardship as their greatest challenge associated with MMT, further exacerbated by other barriers including the conflict of clinic opening hours and working schedules, discrimination from employers, and COVID-19-related restrictions. Additionally, participants identified issues with dose adjustment and emergency treatment continuation. CONCLUSIONS: This study outlines the overall improvement in the quality of life of long-term MMT participants. However, it highlights the need for official guidelines for dose adjustment and emergency treatment continuation as well as the provision of health education, job referrals, and flexibility of clinic opening times to facilitate the return to society receiving participants. Establishing a follow-up mechanism for those receiving MMT is also recommended to prevent relapses to heroin and other illicit substances.

Variation in Use of Medications for Opioid Use Disorder in Critically Ill Patients Across the United States.

OBJECTIVES: To describe practice patterns surrounding the use of medications to treat opioid use disorder (MOUD) in critically ill patients. DESIGN: Retrospective, multicenter, observational study using the Premier AI Healthcare Database. SETTING: The study was conducted in U.S. ICUs. PATIENTS: Adult (≥ 18 yr old) patients with a history of opioid use disorder (OUD) admitted to an ICU between 2016 and 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 108,189 ICU patients (658 hospitals) with a history of OUD, 20,508 patients (19.0%) received MOUD. Of patients receiving MOUD, 13,745 (67.0%) received methadone, 2,950 (14.4%) received buprenorphine, and 4,227 (20.6%) received buprenorphine/naloxone. MOUD use occurred in 37.9% of patients who received invasive mechanical ventilation. The median day of MOUD initiation was hospital day 2 (interquartile range [IQR] 1-3) and the median duration of MOUD use was 4 days (IQR 2-8). MOUD use per hospital was highly variable (median 16.0%; IQR 10-24; range, 0-70.0%); admitting hospital explained 8.9% of variation in MOUD use. A primary admitting diagnosis of unintentional poisoning (aOR 0.41; 95% CI, 0.38-0.45), presence of an additional substance use disorder (aOR 0.66; 95% CI, 0.64-0.68), and factors indicating greater severity of illness were associated with reduced odds of receiving MOUD in the ICU. CONCLUSIONS: In a large multicenter, retrospective study, there was large variation in the use of MOUD among ICU patients with a history of OUD. These results inform future studies seeking to optimize the approach to MOUD use during critical illness.

Sexually transmitted and blood-borne infection risk reduction with methadone and buprenorphine/naloxone among people with prescription-type opioid use disorder: Findings from a Canadian pragmatic randomized trial.

INTRODUCTION: People who use drugs are disproportionally affected by sexually transmitted and blood-borne infections (STBBIs). While the benefits of methadone in reducing injecting-risk behaviours are well documented, less is known on its impacts on sexual-related risks, as well as its comparative effectiveness to buprenorphine/naloxone, particularly in the context of highly potent opioids. The aim of this study was to estimate the relative effects of buprenorphine/naloxone and methadone on injecting and STBBI risks among people with prescription-type opioid use disorder (POUD). METHODS: Secondary analysis of a pan-Canadian pragmatic 24-week randomized clinical trial comparing methadone and buprenorphine/naloxone models of care among 272 people with POUD (including licit or illicit opioid analgesics, fentanyl). The Risk Behaviour Survey was used to collect injecting and sexual risks at baseline, and weeks 12 and 24. RESULTS: In total, 210 participants initiated treatment (103 buprenorphine/naloxone and 107 methadone). At baseline, 113/205 (55.1%) participants reported recently injecting drugs, 37/209 (17.7%) unsafe injection practices and 67/162 (41.4%) high-risk sex. Both methadone and buprenorphine/naloxone were associated with reductions in the prevalence of injection drug use and high-risk sex at weeks 12 and 24 with no interactions between treatment arm and time. CONCLUSION: Methadone and buprenorphine/naloxone were similarly effective in reducing injecting and sexual risk behaviours among people with POUD. CLINICAL TRIALS REGISTRATION: clinicaltrials.gov NCT03033732.

Comparative Analysis of Instrumental Variables on the Assignment of Buprenorphine/Naloxone or Methadone for the Treatment of Opioid Use Disorder.

BACKGROUND: Instrumental variable (IV) analysis provides an alternative set of identification assumptions in the presence of uncontrolled confounding when attempting to estimate causal effects. Our objective was to evaluate the suitability of measures of prescriber preference and calendar time as potential IVs to evaluate the comparative effectiveness of buprenorphine/naloxone versus methadone for treatment of opioid use disorder (OUD). METHODS: Using linked population-level health administrative data, we constructed five IVs: prescribing preference at the individual, facility, and region levels (continuous and categorical variables), calendar time, and a binary prescriber's preference IV in analyzing the treatment assignment-treatment discontinuation association using both incident-user and prevalent-new-user designs. Using published guidelines, we assessed and compared each IV according to the four assumptions for IVs, employing both empirical assessment and content expertise. We evaluated the robustness of results using sensitivity analyses. RESULTS: The study sample included 35,904 incident users (43.3% on buprenorphine/naloxone) initiated on opioid agonist treatment by 1585 prescribers during the study period. While all candidate IVs were strong (A1) according to conventional criteria, by expert opinion, we found no evidence against assumptions of exclusion (A2), independence (A3), monotonicity (A4a), and homogeneity (A4b) for prescribing preference-based IV. Some criteria were violated for the calendar time-based IV. We determined that preference in provider-level prescribing, measured on a continuous scale, was the most suitable IV for comparative effectiveness of buprenorphine/naloxone and methadone for the treatment of OUD. CONCLUSIONS: Our results suggest that prescriber's preference measures are suitable IVs in comparative effectiveness studies of treatment for OUD.

Medications for Opioid Use Disorder and Mortality and Hospitalization Among People With Opioid Use-related Infections.

BACKGROUND: Severe skin and soft tissue infections related to injection drug use have increased in concordance with a shift to heroin and illicitly manufactured fentanyl. Opioid agonist therapy medications (methadone and buprenorphine) may improve long-term outcomes by reducing injection drug use. We aimed to examine the association of medication use with mortality among people with opioid use-related skin or soft tissue infections. METHODS: An observational cohort study of Medicaid enrollees aged 18 years or older following their first documented medical encounters for opioid use-related skin or soft tissue infections during 2007-2018 in North Carolina. The exposure was documented medication use (methadone or buprenorphine claim) in the first 30 days following initial infection compared with no medication claim. Using Kaplan-Meier estimators, we examined the difference in 3-year incidence of mortality by medication use, weighted for year, age, comorbidities, and length of hospital stay. RESULTS: In this sample, there were 13,286 people with opioid use-related skin or soft tissue infections. The median age was 37 years, 68% were women, and 78% were white. In Kaplan-Meier curves for the total study population, 12 of every 100 patients died during the first 3 years. In weighted models, for every 100 people who used medications, there were four fewer deaths over 3 years (95% confidence interval = 2, 6). CONCLUSION: In this study, people with opioid use-related skin and soft tissue infections had a high risk of mortality following their initial healthcare visit for infections. Methadone or buprenorphine use was associated with reductions in mortality.

Continuous Wound Irrigation and Intraoperative Methadone Decreases Opioid Use and Shortens Length of Stay After CRS/HIPEC.

BACKGROUND: Epidural analgesia is resource and labor intense and may limit postoperative management options and delay discharge. This study compared postoperative outcomes after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) with epidural analgesia versus continuous wound infusion system (CWIS) with/without intraoperative methadone. METHODS: A single-institution, retrospective chart review was performed including all patients undergoing open CRS/HIPEC from 2018 to 2021. Patient demographics, surgical characteristics, length of stay, and in-hospital analgesic use were reviewed. In-hospital opioid exposure in morphine milligram equivalents (MME) was calculated. Multivariate analysis (MVA) for mean total and daily opioid exposure was conducted. RESULTS: A total of 157 patients were included. Fifty-three (34%) had epidural analgesia, 96 (61%) had CWIS, and 79 (50%) received methadone. Length of stay was significantly shorter with CWIS + methadone versus epidural (7 vs. 8 days, p < 0.01). MVA showed significantly lower mean total and daily opioid exposure with CWIS+methadone versus epidural (total: 252.8 ± 17.7 MME vs. 486.8 ± 86.6 MME; odds ratio [OR] 0.72, 95% confidence interval [CI] 0.52-0.98, p = 0.04; Daily: 32.8 ± 2.0 MME vs. 51.9 ± 5.7 MME, OR 0.72, 95% CI 0.52-0.99, p ≤ 0.05). The CWIS-only group (n = 17) had a significantly lower median oral opioid exposure versus epidural (135 MME vs. 7.5 MME, p < 0.001) and longer length of stay versus CWIS + methadone (9 vs. 7 days, p = 0.04), There were no CWIS or methadone-associated complications and one epidural abscess. CONCLUSIONS: CWIS + methadone safely offers better pain control with less in-hospital opioid use, shorter length of stay, and decreased resource utilization compared with epidural analgesia in patients undergoing CRS-HIPEC.

Natural Products Inhibition of Cytochrome P450 2B6 Activity and Methadone Metabolism.

Methadone is cleared predominately by hepatic cytochrome P450 (CYP) 2B6-catalyzed metabolism to inactive metabolites. CYP2B6 also catalyzes the metabolism of several other drugs. Methadone and CYP2B6 are susceptible to pharmacokinetic drug-drug interactions. Use of natural products such as herbals and other botanicals is substantial and growing, and concomitant use of prescription medicines and non-prescription herbals is common and may result in interactions, often precipitated by CYP inhibition. Little is known about herbal product effects on CYP2B6 activity, and CYP2B6-catalyzed methadone metabolism. We screened a family of natural product compounds used in traditional medicines, herbal teas, and synthetic analogs of compounds found in plants, including kavalactones, flavokavains, chalcones and gambogic acid, for inhibition of expressed CYP2B6 activity and specifically inhibition of CYP2B6-mediated methadone metabolism. An initial screen evaluated inhibition of CYP2B6-catalyzed 7-ethoxy-4-(trifluoromethyl) coumarin O-deethylation. Hits were further evaluated for inhibition of racemic methadone metabolism, including mechanism of inhibition and kinetic constants. In order of decreasing potency, the most effective inhibitors of methadone metabolism were dihydromethysticin (competitive, K i 0.074 µM), gambogic acid (noncompetitive, K i 6 µM), and 2,2'-dihydroxychalcone (noncompetitive, K i 16 µM). Molecular modeling of CYP2B6-methadone and inhibitor binding showed substrate and inhibitor binding position and orientation and their interactions with CYP2B6 residues. These results show that CYP2B6 and CYP2B6-catalyzed methadone metabolism are inhibited by certain natural products, at concentrations which may be clinically relevant. SIGNIFICANCE STATEMENT: This investigation identified several natural product constituents which inhibit in vitro human recombinant CYP2B6 and CYP2B6-catalyzed N-demethylation of the opioid methadone. The most potent inhibitors (K i) were dihydromethysticin (0.074 µM), gambogic acid (6 µM) and 2,2'-dihydroxychalcone (16 µM). Molecular modeling of ligand interactions with CYP2B6 found that dihydromethysticin and 2,2'-dihydroxychalcone bound at the active site, while gambogic acid interacted with an allosteric site on the CYP2B6 surface. Natural product constituents may inhibit CYP2B6 and methadone metabolism at clinically relevant concentrations.

In-Hospital Methadone Enrollment: a Novel Program to Facilitate Linkage from the Hospital to the Opioid Treatment Program for Vulnerable Patients with Opioid Use Disorder.

INTRODUCTION: Methadone ameliorates opioid withdrawal among hospitalized patients with opioid use disorder (OUD). To continue methadone after hospital discharge, patients must enroll in an opioid treatment program (OTP) per federal regulations. Uncontrolled opioid withdrawal is a barrier to linkage from hospital to OTP. AIM: Describe a federally compliant In-Hospital Methadone Enrollment Team (IN-MEET) that enrolls hospitalized patients with OUD into an OTP with facilitated hospital to OTP linkage. SETTING: Seven hundred-bed university hospital in Aurora, CO. PROGRAM DESCRIPTION: A physician dually affiliated with a hospital's addiction consultation service and a community OTP completes an in-hospital, face-to-face medical assessment required by federal law and titrates methadone to comfort. An OTP-affiliated nurse with hospital privileges completes a psychosocial evaluation and provides case management by arranging transportation and providing weekly telephone check-ins. PROGRAM EVALUATION METRICS: IN-MEET enrollments completed, hospital to OTP linkage, and descriptive characteristics of patients who completed IN-MEET enrollments compared to patients who completed community OTP enrollments. RESULTS: Between April 2019 and April 2023, our team completed 165 IN-MEET enrollments. Among a subset of 73 IN-MEET patients, 56 (76.7%) presented to the OTP following hospital discharge. Compared to community OTP enrolled patients (n = 1687), a higher percentage of IN-MEET patients were older (39.7 years, standard deviation [SD] 11.2 years vs. 36.1 years, SD 10.6 years) and were unhoused (n = 43, 58.9% vs. n = 199, 11.8%). Compared to community OTP enrolled patients, a higher percentage of IN-MEET patients reported heroin or fentanyl as their primary substance (n = 53, 72.6% vs. n = 677, 40.1%), reported methamphetamine as their secondary substance (n = 27, 37.0% vs. n = 380, 22.5%), and reported they injected their primary substance (n = 46, 63.0% vs. n = 478, 28.3%). CONCLUSION: IN-MEET facilitates hospital to OTP linkage among a vulnerable population. This model has the potential to improve methadone access for hospitalized patients who may not otherwise seek out treatment.

Pregnancy Rates Among Women Treated with Medication for Opioid Use Disorder.

BACKGROUND: Treatment-seeking people with opioid use disorder (OUD) who are capable of pregnancy need accurate information about the potential impact of medication to treat OUD (MOUD) on fertility to make informed choices about treatment that are consistent with their reproductive wishes. There is a dearth of research on fertility associated with MOUD receipt in birthing people with OUD. OBJECTIVE: To estimate the association between treatment with MOUD and odds of conception among birthing people using national administrative claims. DESIGN: Retrospective case-crossover study using multi-state US administrative data (2006-2016). Dates of conception were estimated from delivery dates and served as "case" days for which MOUD exposures were compared to those on all other ("control") days of insurance enrollment. PARTICIPANTS: Treatment-seeking people with OUD with a delivery during the observation period. MAIN MEASURES: Odds ratios for conception from within-person fixed effects models were modeled as a function of exposure to MOUD (buprenorphine, methadone, extended-release depot naltrexone, or oral naltrexone) using conditional logistic regression. KEY RESULTS: A total of 21,928 births among 19,133 people with OUD were identified. In the sample, 5873 people received buprenorphine, 1825 methadone, 486 extended-release naltrexone, and 714 oral naltrexone. Participants could receive more than one type of MOUD. Mean age was 28.2 years (SD = 2.2; range = 16-45), with 76.2% having Medicaid. vs. commercial insurance. Compared to no MOUD, periods of methadone (aOR = 0.55 [95% CI = 0.48-0.63]) or buprenorphine receipt (aOR = 0.84 [0.77-0.91]) were associated with fewer conceptions. Treatment periods with extended-release depot naltrexone compared to no medication were associated with higher odds of conception (aOR = 1.75 [1.22-2.50]) and there was no significant difference in conception with oral naltrexone (aOR = 1.02 [0.67-1.54]). CONCLUSIONS: The association between MOUD and odds of conception among birthing people varied by type of MOUD, with extended-release naltrexone associated with higher odds of conceiving compared to no treatment. Clinical studies are urgently needed to investigate these findings further.

Experiences of Aging with Opioid Use Disorder and Comorbidity in Opioid Treatment Programs: A Qualitative Analysis.

BACKGROUND: The number of older adults entering opioid treatment programs (OTPs) to treat opioid use disorder (OUD) is increasing. However, the lived experiences of aging in OTPs have not been examined. OBJECTIVE: To explore the aging experience with OUD and barriers to medical care for older adults who receive care in OTPs. DESIGN: From November 2021 to July 2022, we conducted 1-to-1, semi-structured qualitative interviews in English and Spanish, audio-recorded, transcribed, systematically coded, and analyzed to identify key themes regarding the challenges of aging with OUD and managing chronic diseases. PARTICIPANTS: Thirty-six adults aged ≥ 55 enrolled in OTPs in San Diego, California. APPROACH: A descriptive qualitative approach was used. Major themes and subthemes were identified through thematic analysis until thematic saturation was reached. KEY RESULTS: All participants were on methadone and had a mean age of 63.4 (SD 5.1) years; 11 (30.6%) identified as female, 14 (39%) as Hispanic/Latino, and 11 (36%) as Black, with a mean duration of methadone treatment of 5.6 years. Chronic diseases were common, with 21 (58.3%) reporting hypertension, 9 (25%) reporting untreated hepatitis C, and 32 (88.9%) having ≥ 2 chronic diseases. Three major themes emerged: (1) avoidance of medical care due to multiple intersectional stigmas, including those related to drug use, substance use disorder (SUD) treatment, ageism, and housing insecurity; (2) increasing isolation with aging and loss of family and peer groups; (3) the urgent need for integrating medical and aging-focused care with OUD treatment in the setting of increasing health and functional challenges. CONCLUSIONS: Older adults with OUD reported increasing social isolation and declining health while experiencing multilevel stigma and discrimination. The US healthcare system must transform to deliver age-friendly care that integrates evidence-based geriatric models of care incorporated with substance use disorder treatment and addresses the intersectional stigma this population has experienced in healthcare settings.

Treatment for Opioid Use Disorder: Population Estimates - United States, 2022.

In 2022, 81,806 opioid-involved overdose deaths were reported in the United States, more than in any previous year. Medications for opioid use disorder (OUD), particularly buprenorphine and methadone, substantially reduce overdose-related and overall mortality. However, only a small proportion of persons with OUD receive these medications. Data from the 2022 National Survey on Drug Use and Health were applied to a cascade of care framework to estimate and characterize U.S. adult populations who need OUD treatment, receive any OUD treatment, and receive medications for OUD. In 2022, 3.7% of U.S. adults aged ≥18 years needed OUD treatment. Among these, only 25.1% received medications for OUD. Most adults who needed OUD treatment either did not perceive that they needed it (42.7%) or received OUD treatment without medications for OUD (30.0%). Compared with non-Hispanic Black or African American and Hispanic or Latino adults, higher percentages of non-Hispanic White adults received any OUD treatment. Higher percentages of men and adults aged 35-49 years received medications for OUD than did women and younger or older adults. Expanded communication about the effectiveness of medications for OUD is needed. Increased efforts to engage persons with OUD in treatment that includes medications are essential. Clinicians and other treatment providers should offer or arrange evidence-based treatment, including medications, for patients with OUD. Pharmacists and payors can work to make these medications available without delays.

Opioid-related deaths and their counterpart by occurrence era, age group and coimplicated drugs: Scotland vs. England and Wales.

AIMS: Compare by occurrence era and age group how opioid-related deaths (ORDs) and their counterpart evolved in Scotland vs. England and Wales during 2006-2020. For Scotland, compare coimplication rates between ORDs and non-ORDs for any benzodiazepine, cocaine or gabapentin/pregabalin, and consider whether coimplication in ORDs depended on opioid-specificity. METHODS: Cross-tabulations of drug misuse deaths (DMDs) obtained by 3 yearly occurrence era (2006-2008 to 2018-2020) and age group (under 25, 25-34, 35-44, 45-54, 55+ years) for England and Wales and subdivided by whether at least 1 opiate was mentioned on death certificate (DMD-Os or not); and of Scotland's opioid-related deaths (ORDs vs. non-ORDs) together with (i) coimplication by any benzodiazepine, cocaine or gabapentin/pregabalin; and (ii) opioid-specificity of ORDs. ORD is defined by heroin/morphine, methadone or buprenorphine being implicated in DMD. RESULTS: Per era between 2012-2014 and 2018-2020, Scotland's ORDs increased by 54% and non-ORDs by 34%. Increase in DMD-Os in England and Wales was more modest. Cocaine was implicated in 83% of Scotland's 2690 non-ORDs during 2006-2020; and any benzodiazepine in 53% of 8409 ORDs. However, in 2018-2020, coimplication rates in 2926 ORDs (880 non-ORDs) were 81% (33%) for any benzodiazepine, 30% (74%) for cocaine and 38% (22%) for gabapentin/pregabalin. Coimplication rate in 2018-2020 for any benzodiazepine was lowest at 70% (616/877) for heroin/morphine ORDs; and, by age group, at 66% (160/241) for ORDs aged 55+ years. CONCLUSIONS: Drug testing to inform users, shared intelligence between police and public health for earlier detection of changes in supply and monitoring of prescribed daily-dose of methadone are urgent.

Gabapentinoids in Ireland 2010 to 2020: An observational study of trends in gabapentinoid prescribing, law enforcement drug seizures and postmortem toxicology.

AIMS: We explored trends in gabapentinoid prescribing, drug seizures and postmortem toxicology using a national pharmacy claims database, law enforcement drug seizures data and a population-based postmortem toxicology database. METHODS: Gabapentinoid prescribing rates per 100 000 eligible population (2010-2020), annual number of drug seizures involving gabapentinoids (2012-2020) and gabapentinoid detection (positive) rates per 100 postmortem toxicology case (2013-2020) were calculated. Negative binomial regression models were used to evaluate longitudinal trends for gabapentin and pregabalin separately. RESULTS: Gabapentin (adjusted rate ratio [RR] 1.06, 95% confidence interval [CI] 1.05-1.06, P < .001) and pregabalin (adjusted RR 1.08, 95% CI 1.08-1.09, P < .001) prescribing increased annually, with higher rates of pregabalin (vs. gabapentin) observed every year. Drug seizures involving pregabalin also increased over time (RR 1.54 95% CI 1.25-1.90, P < .0001). Of the 26 317 postmortem toxicology cases, 0.92% tested positive for gabapentin, and 6.37% for pregabalin. Detection rates increased for both gabapentin (RR 1.28, 95% CI 1.11-1.48, P < .001) and pregabalin (RR 1.13, 95% CI 1.11-1.48, P < .001) between 2013 and 2020. A total of 1901 cases (7.2%) tested positive for heroin/methadone; this sub-group had a higher detection rate for pregabalin (n = 528, 27.8%) and gabapentin (n = 41, 2.2%) over the study period, with a high burden of codetections for pregabalin with benzodiazepines (peaking at 37.3% in 2018), and pregabalin with prescription opioids (peaking at 28.9% in 2020). CONCLUSION: This study raises concerns regarding the wide availability of pregabalin in Ireland, including a growing illicit supply, and the potential for serious harm arising from poly drug use involving pregabalin among people who use heroin or methadone.

Effects of prenatal opioid exposure on infant sympathetic and parasympathetic nervous system activity.

Prenatal opioid exposure has been associated with developmental problems, including autonomic nervous system dysregulation. However, little is known about the effects of prenatal opioid exposure on the autonomic nervous system beyond the first days of life, particularly across both the parasympathetic and sympathetic branches, and when accounting for exposure to other substances. The present study examined the effects of prenatal exposure to opioid agonist therapy (OAT, e.g., methadone) and other opioids on infant autonomic nervous system activity at rest and in response to a social stressor (the Still-Face Paradigm) at six months among 86 infants varying in prenatal opioid and other substance exposure. Results indicated that OAT and other opioids have unique effects on the developing autonomic nervous system that may further depend on subtype (i.e., methadone versus buprenorphine) and timing in gestation. Results are discussed in the context of theoretical models of the developing stress response system.

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.

DRD2 TaqIA polymorphism-related functional connectivity between anterior insula and dorsolateral prefrontal cortex predicts the retention time in heroin-dependent individuals under methadone maintenance treatment.

BACKGROUND: Dopamine receptor D2 (DRD2) TaqIA polymorphism has an influence on addiction treatment response and prognosis by mediating brain dopaminergic system efficacy. Insula is crucial for conscious urges to take drugs and maintain drug use. However, it remains unclear about the contribution of DRD2 TaqIA polymorphism to the regulation of insular on addiction behavioral and its relation with the therapeutic effect of methadone maintenance treatment (MMT). METHODS: 57 male former heroin dependents receiving stable MMT and 49 matched male healthy controls (HC) were enrolled. Salivary genotyping for DRD2 TaqA1 and A2 alleles, brain resting-state functional MRI scan and a 24-month follow-up for collecting illegal-drug-use information was conducted and followed by clustering of functional connectivity (FC) patterns of HC insula, insula subregion parcellation of MMT patients, comparing the whole brain FC maps between the A1 carriers and non-carriers and analyzing the correlation between the genotype-related FC of insula sub-regions with the retention time in MMT patients by Cox regression. RESULTS: Two insula subregions were identified: the anterior insula (AI) and the posterior insula (PI) subregion. The A1 carriers had a reduced FC between the left AI and the right dorsolateral prefrontal cortex (dlPFC) relative to no carriers. And this reduced FC was a poor prognostic factor for the retention time in MMT patients. CONCLUSION: DRD2 TaqIA polymorphism affects the retention time in heroin-dependent individuals under MMT by mediating the functional connectivity strength between left AI and right dlPFC, and the two brain regions are promising therapeutic targets for individualized treatment.