Faculty Bibliography

Methadone is a highly effective treatment for opioid use disorder. However, its public health impact in the U.S. has long been constrained by strict regulations requiring dispensing through specialty opioid treatment programs (OTPs). In 2021, the U.S. Drug Enforcement Administration authorized mobile medication units (MMUs) to dispense methadone in community settings, raising hopes that mobile delivery could expand access for underserved populations. This commentary examines New York State's early experience implementing MMUs as a case study of both the opportunities and persistent challenges associated with this care delivery model in the U.S. We discuss how burdensome methadone requirements, high start-up and operating costs, complex staffing and logistical burdens, community opposition, and a continued emphasis on diversion control over patient access have limited the ability to effectively scale MMUs as a low-threshold treatment option. Although MMUs have and will continue to improve convenience and access for some patients, their potential to substantially improve geographic access, provide lower-threshold care, and deliver comprehensive OUD services is inhibited by the broader U.S. "methadone exceptionalism" framework, which silos methadone as a separate and more restrictive treatment modality requiring excessive vigilance and oversight . We argue that without greater regulatory clarity, flexibility, and alignment with patient-centered care goals, MMUs may likely remain a welcomed but modest, rather than transformative, innovation in addressing methadone gaps in the United States.

BACKGROUND:The illicit drug landscape in South America is going through a major shift. The appearance of Tusi (or "pink cocaine"), a mixture often containing ketamine and MDMA, along with the growing presence of synthetic opioids like fentanyl and nitazenes, signals a new chapter in the region's drug use, which has been traditionally dominated by alcohol, cannabis, and cocaine. MAIN BODY/METHODS:Drawing on data on seizures, forensic analyses, warning systems, and surveys from Brazil, Chile, and Colombia, this perspective highlights three movements of the drug supply: non-prescribed and synthetic opioids, ketamine, and Tusi. We also elaborate on their unique public health challenges. Brazil and Chile have seen an increase in non-prescribed opioid use, some of them diverted from healthcare, accompanied by seizures of illicit fentanyl and the discovery of nitazene production in Brazil in May 2025. Colombia, while historically experiencing low opioid use, has documented fentanyl analogs in ketamine and MDMA/Ecstasy samples, mixed with various other contaminants, thus increasing risks among people who use them. Concurrently, ketamine and Tusi use are expanding rapidly across all three countries, particularly among nightclub attendees and youth with criminal-legal involvement. Tusi's unpredictable composition poses heightened overdose risks, especially in settings lacking drug-checking and overdose-prevention education and programs. Furthermore, South America has minimal opioid agonist therapy coverage, limited naloxone access, and underdeveloped harm reduction systems. CONCLUSION/CONCLUSIONS:The emergence of synthetic opioids, ketamine, and Tusi signals a new synthetic drug phase in South America's supply. The convergence of traditional drugs with potent new substances poses important health-related harms. Strengthening regional surveillance, toxicological monitoring, and harm reduction services are urgently needed. Coordinated international research and public health responses will be essential to prevent a drug crisis.

BACKGROUND:Overdose prevention centers (OPCs) may reduce public drug use and, with it, policing of people who use drugs in the communities surrounding these sites. We applied an augmented synthetic control method to assess changes in pedestrian stops before and after the November 2021 opening of two OPCs (Washington Heights and East Harlem) in New York City (NYC). METHODS:We retrieved pedestrian stop information from the New York Police Department's (NYPD) Stop, Question, and Frisk, program from January 2017 to December 2024, and created bimonthly averages using five- and ten-minute walking buffers surrounding the OPCs and 57 donor sites (syringe service and opioid treatment programs) as outcomes. Covariates were derived from American Community Survey, NYPD Calls for Services, and SafeGraph pedestrian mobility estimates. RESULTS:The opening of the Washington Heights OPC was associated with a reduction of 2.8 bimonthly average pedestrian stops in the post-intervention period when using five-minute walking buffers, although results were compatible with increases and reductions (95%CI=-9.4, 4.0). For ten-minute walking buffers, results were compatible with a wide range of reductions (ATT=-9.2 [95%CI=-18.3, -1.3]). East Harlem OPC showed larger point estimates when examining both distances (ATT=-8.4 [95%CI=-12.2, -4.5] and ATT=-13.7 [95%CI=-22.1, -4.2] with five- and ten-minute walking buffers, respectively). For both sites, permutation tests suggested that these reductions fell within the range of possible donor-unit placebo effects. CONCLUSIONS:Our study shows limited evidence of an effect of NYC's first two OPCs on pedestrian stops in their immediate vicinity, with a potential decrease concentrated in the first two years at the East Harlem location.

OBJECTIVES/OBJECTIVE:Policy reforms are being considered to increase methadone treatment (MT) access for opioid use disorder in the United States. Proponents of more structured MT reference risks of diversion, including non-prescribed use or redistribution of methadone, and overdose as arguments for limiting access to specialty settings. However, the scientific evidence behind these claims has not been thoroughly reviewed. METHODS:We conducted a narrative review of studies on methadone diversion, diverted methadone-involved overdoses, and how these compare in countries with specialty-care-only policies (methadone dispensed only through regulated treatment programs) versus general physician-prescribing policies (physicians prescribe methadone in office-based settings). A narrative approach was chosen, given substantial heterogeneity in study designs, diversion definitions, outcome measures, and data sources. We synthesize and discuss findings from international papers published before October 2025. RESULTS:We identified 29 articles studying methadone diversion or diverted methadone-involved overdoses in 7 countries. Lifetime methadone diversion occurrence varied between 6% and 68%, and using diverted methadone occurrence varied between 22% and 88%. Diverting methadone was most often done to help sick friends/partners. Common reasons for using diverted methadone were preventing withdrawal and avoiding opioid use. Three studies found no association between self-reported diverted methadone use and increased individual-level risk of overdose. CONCLUSIONS:The link between specialty-care-only policies and lower diversion and overdose risk is not supported by the reviewed literature. Policymakers should weigh diversion risks against benefits of lives saved through expanded MT access. Further research is needed to better understand the circumstances related to diverted methadone and inform policy-making that appropriately mitigates risks.

BACKGROUND/UNASSIGNED:The opioid overdose crisis remains a public health emergency in the United States. Evidence-based practices-including medications for opioid use disorder (MOUD) and naloxone distribution-can reduce harms, but their community-level cost-effectiveness is uncertain and may vary locally. We aimed to evaluate the cost-effectiveness of enhanced community-level implementation of evidence-based practices for opioid use disorder (OUD). METHODS/UNASSIGNED:We used a validated microsimulation model of OUD, calibrated with data from the HEALing Communities Study across 26 highly impacted communities in Massachusetts, New York, and Ohio. Six intervention scenarios for 2025-2030: maintaining 2024 evidence-based practice levels (status quo); improved naloxone distribution; improved MOUD retention; improved MOUD initiation; combined initiation and retention; and combined initiation, retention, and naloxone distribution. Outcomes included opioid overdose deaths (OODs), non-overdose opioid-related deaths, quality-adjusted life years (QALYs), costs (healthcare and societal), and incremental cost-effectiveness ratios (ICERs). FINDINGS/UNASSIGNED:Maintaining 2024 evidence-based practice levels was projected to yield OODs of 39-468 per 100,000 and non-overdose deaths of 238-3018 per 100,000 across communities. Enhancing MOUD initiation, retention, and naloxone distribution reduced OODs by 15-40% and non-overdose deaths by 7-24%, producing the largest QALY gains (1006-38,292). From the healthcare perspective, improved initiation plus retention was cost-effective in all communities (ICER US$11,765-US$91,058 per QALY); from the societal perspective, all enhanced scenarios were cost-saving (US$121 million-US$4.74 billion net savings). INTERPRETATION/UNASSIGNED:Community-level enhancement of MOUD initiation and retention, and for some communities also enhancing naloxone distribution, can substantially reduce opioid-related-overdose and non-overdose-deaths. These strategies are cost-effective from a healthcare perspective and cost-saving from a societal perspective, supporting investment in comprehensive, community-tailored interventions. FUNDING/UNASSIGNED:NIH HEAL Initiative.

BACKGROUND:Individuals with opioid use disorder (OUD) may experience fewer barriers to treatment following incarceration if offered in-jail medications for OUD (MOUD). We aimed to identify care trajectories of community OUD treatment after incarceration and examine the association between receiving in-jail MOUD and experiencing specific community treatment trajectories. METHODS:This retrospective cohort study using matched New York City (NYC) health care administrative data included adults with OUD incarcerated on or after May 2011 and discharged during 2014-2017. We defined states of community OUD treatment at the weekly level over one year following index jail discharge and performed state sequence analysis (SSA) to identify trajectories of treatment after jail and assessed the influence of receiving in-jail MOUD on treatment trajectories. RESULTS:Of 14,923 eligible individuals, 26.2% received in-jail MOUD. SSA identified eight clusters of community care trajectories: continuous methadone treatment (9.7%), methadone treatment discontinuation (3.7%), methadone treatment and reincarceration (6.7%), methadone treatment initiation (4.8%), continuous reincarceration (3.5%), short reincarceration with little community treatment (20.3%), long reincarceration with little community treatment (7.0%), and no community OUD treatment or reincarceration (44.5%). Receiving in-jail MOUD was associated with belonging to the continuous methadone treatment cluster compared to the no community OUD treatment or reincarceration cluster (adjusted OR: 12.5, 95% CI: 9.9-15.7). CONCLUSION/CONCLUSIONS:We identified eight unique patterns of community OUD treatment after jail release. Receipt of in-jail MOUD was associated with belonging to the continuous methadone treatment cluster. These findings suggest that provision of in-jail MOUD could improve methadone uptake in the community.

INTRODUCTION/BACKGROUND:A 2021 federal rule permits opioid treatment programs (OTPs) to provide methadone through mobile medication units (MMUs), creating an opportunity to provide medication for people in residential care facilities. We used simulations to quantify the potential of MMUs to expand methadone access to people residing in residential substance use treatment facilities (RTF), skilled nursing facilities (SNF), and nursing facilities (NF) in New York State under different scenarios. METHODS:For each facility (RTF, SNF, and NF), a need score was created using three items: facility opioid use disorder (OUD) population, driving distance to nearest OTP, and county overdose mortality rate. We then demonstrated potential patient reach following the launch of 50 hypothetical MMUs making one stop per day to the highest need facilities. In refinements, we examined three additional scenarios involving more daily stops and prioritizing rural areas. RESULTS:Our sample included 3214 people with OUD estimated to be housed in 1052 facilities in New York, with the majority in RTFs (51.5%). The demonstrated percentage of OUD population served ranged from 23.5% to 35.8%, and the percentage of facilities served ranged from 23.8% to 37.4%. Each scenario reached a large percentage of rural facilities (73-76%). Prioritizing rural facilities decreased the proportion of OUD population served (10% reduction) but did not substantially increase driving time. Allowing multiple stops increased the proportion of OUD population served (32-36% vs. 24-26%). CONCLUSIONS:Using methods based on location information and spatial relationships, state officials can develop priorities and assess tradeoffs of MMU deployment and distribution strategies.

Despite robust evidence that medications for opioid use disorder (MOUD) reduce overdose and mortality, substantial care gaps remain following opioid-related hospital encounters. The opioid use disorder (OUD) Cascade of Care framework conceptualizes progression from identification to treatment initiation and retention, yet limited research has examined how real-world OUD treatment trajectories unfold, particularly across treatment episodes and multiple care settings. This paper describes an NIH-funded study protocol (1R01DA061367-01A1) to conduct a longitudinal observational study using linked administrative data across New York City to characterize OUD treatment trajectories following opioid-related hospital encounters. Using the OUD Cascade of Care framework, we will apply state sequence analysis to identify common patterns of OUD treatment engagement in the year following hospitalization, including transitions between treatment modalities and periods in and out of care. We will examine how care trajectories vary by individual and neighborhood characteristics, and assess associations between trajectories and key outcomes, including rehospitalization, overdose, and mortality. By applying novel data-driven longitudinal methods, this study will advance understanding of the complex, non-linear nature of OUD treatment engagement. Findings will inform health system and policy efforts to identify populations at elevated risk, hospital-based interventions, and opportunities to address gaps in care to reduce overdose-related harms.

IMPORTANCE/UNASSIGNED:Syringe services programs (SSPs) are evidence-based interventions that reduce bloodborne infections and injection-related harms among people who inject drugs, yet access remains limited and geographically uneven across the US. OBJECTIVE/UNASSIGNED:To quantify the travel time, distance, and cost required to reach the nearest SSP from population-weighted census tracts nationwide and to examine differences by urbanicity, state, and SSP legality. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:This cross-sectional geospatial study linked all known SSP locations as of August 2024 to the population-weighted centroids of census tracts in the 50 US states and the District of Columbia. Analyses were conducted between December 2024 and February 2026. MAIN OUTCOMES AND MEASURES/UNASSIGNED:Population-weighted mean and median driving time, distance, and cost to access the nearest SSP, stratified by National Center for Health Statistics urban-rural county category and SSP legal status. Costs were estimated using 2024 Internal Revenue Service (IRS) medical mileage deduction rates and 2022 state-specific gasoline prices. RESULTS/UNASSIGNED:In 1338 SSPs across 83 780 census tracts, the population-weighted mean 1-way driving time to the nearest SSP was 46.1 minutes (95% CI, 45.7-46.5 minutes) and the median was 23.3 minutes (IQR, 12.2-58.5 minutes). Altogether, 23.1% of the population lived more than 60 minutes from an SSP and 12.6% lived over 120 minutes away. The mean 1-way driving distance was 41.8 miles (95% CI, 41.3-42.2 miles). The mean 1-way driving cost was $8.77 (95% CI, $8.68-$8.86) using the 2024 IRS mileage rate and $6.91 (95% CI, $6.84-$6.98) using state mean gasoline prices in 2022. In states where SSPs were legal, mean driving time was 30.1 minutes (95% CI, 29.8-30.4 minutes) and mean cost by IRS mileage rates was $4.94 (IQR, $4.88-$5.00), compared with 110.7 minutes (95% CI, 109.6-111.8 minutes) and $24.19 (IQR, $23.92-$24.46) in states where SSPs were illegal. CONCLUSIONS AND RELEVANCE/UNASSIGNED:This cross-sectional study of travel burden to SSPs found substantial geographic and financial barriers to accessing SSPs across the US, particularly in nonmetropolitan areas. Targeting new SSPs to areas with the greatest travel burden could improve utilization and reduce drug-related morbidity.

BACKGROUND:Overdose rates in the U.S. rose dramatically during the COVID-19 pandemic. Well-documented racial and sociodemographic inequities in the impact of the pandemic suggest the potential for similar inequities for overdose. Our objective was to identify subgroups of New York State Medicaid enrollees who experienced the greatest increases in non-fatal opioid overdose risk following onset of the COVID-19 pandemic. METHODS:Data are from a retrospective cohort of 1,021,889 people enrolled in New York State Medicaid from 2019-2020. To identify subgroups with the greatest increased risk of non-fatal overdose following onset of the COVID-19 pandemic, we used Heterogeneous Treatment Effect (HTE)-Scan, a novel machine learning method developed for accurate and computationally efficient discovery of heterogeneous treatment effects in complex data. RESULTS:In the total sample, risk of non-fatal opioid overdose increased 22% after onset of the pandemic. We also identified two subgroups with elevated risk relative to the total sample: subgroup 1 (Black and Hispanic males aged 45-64 years old with no baseline documentation of opioid use disorder (OUD); N = 53,065) and subgroup 2 (people aged 45-64 years old with documented aged/blind/disabled status and no baseline documentation of OUD; N = 73,694). These subgroups experienced a 54% and 57% increase in non-fatal overdose risk, respectively. CONCLUSIONS:We estimated heterogeneous effects of onset of the COVID-19 pandemic on non-fatal overdose, with elevated risks estimated for older working-aged, structurally disadvantaged adults without documented OUD. These findings illustrate the importance of structural factors in driving heterogeneous risk of overdose following complex social events.