(77) Increased Healthcare Utilization and Acuity Associated With Medetomidine

Background & Introduction: The illicit opioid supply continues to evolve, with increasing sedative adulteration complicating overdose, withdrawal, and acute care utilization. In Allegheny County, Pennsylvania, 2023 drug checking data showed fentanyl was commonly adulterated with xylazine (56%) but not medetomidine. By 2025, medetomidine was detected in 67% of samples, while xylazine prevalence remained similar (54%). Medetomidine, a potent α2-adrenergic agonist, has been increasingly associated with severe toxicity and withdrawal syndromes.
Recent MMWR reports from Pittsburgh and Philadelphia, along with subsequent multicenter studies, describe a severe medetomidine withdrawal syndrome characterized by refractory agitation, autonomic instability, and frequent need for intensive care unit (ICU) admission. These findings suggest that medetomidine adulteration may substantially increase emergency department (ED) utilization and hospitalization among patients with opioid use disorder (OUD).
The objective of this study is to compare ED visit volume, hospital admission rates, and ICU admissions for patients presenting with primary diagnoses of untreated OUD or opioid withdrawal to an urban Pittsburgh ED in 2025 versus 2023. We hypothesize that ED utilization increased in 2025 and that a higher proportion of patients required hospital and ICU admission following the emergence of medetomidine in the local drug supply.

Methods: We conducted a retrospective, observational pre–post analysis comparing ED utilization and hospitalization outcomes at UPMC Mercy Hospital, an urban tertiary care hospital with an on-site hospital-based withdrawal management unit in Pittsburgh, Pennsylvania, during calendar years 2023 and 2025. Data were obtained from the ED operations dashboard maintained by the UPMC Department of Emergency Medicine, which captures encounter-level information including primary ED diagnosis and disposition.
The primary analysis evaluated ED encounters with a primary diagnosis of untreated opioid use disorder (OUD) or opioid withdrawal to assess overall changes in ED volume, hospital admission, and Intensive Care Unit (ICU) utilization among patients presenting with OUD-related conditions.
A secondary analysis examined the subset of encounters with a primary diagnosis of opioid withdrawal alone to better characterize the specific contribution of withdrawal to outcomes observed in the broader OUD cohort.
Descriptive analyses measured the total number of ED encounters, the proportion resulting in hospital admission, and the percentage admitted to the ICU from the ED in both 2023 and 2025, as well as the percent change across this period.

Results: Between 2023 and 2025, substantial increases were observed in ED utilization, hospital admissions, and ICU admissions among patients presenting with primary diagnoses of untreated opioid use disorder (OUD) and/or opioid withdrawal. These findings align with the study objective of evaluating changes in healthcare utilization following shifts in the local illicit opioid supply.
For the combined cohort of ED encounters with a primary diagnosis of untreated OUD or opioid withdrawal, total visits increased from 412 in 2023 to 747 in 2025, representing an 81.3% increase. The proportion of encounters resulting in hospital admission more than doubled, rising from 11.4% (47/412) in 2023 to 26.2% (196/747) in 2025, a 129.8% relative increase. Among admitted patients, ICU utilization increased markedly: ICU admissions rose from 3 patients (6.4% of admitted) in 2023 to 52 patients (26.5% of admitted) in 2025, corresponding to a 314.1% relative increase in the proportion of admitted patients requiring ICU-level care.
More pronounced changes were observed in the opioid withdrawal–only cohort. ED visits for opioid withdrawal increased from 85 encounters in 2023 to 214 encounters in 2025, a 151.8% increase. Hospital admission rates rose from 10.6% (9/85) in 2023 to 34.1% (73/214) in 2025, representing a 221.7% relative increase. Notably, no ICU admissions occurred among opioid withdrawal encounters in 2023, whereas in 2025, 29 admitted patients required ICU care, accounting for 39.2% of admissions.
Across both diagnostic cohorts, increases were observed not only in absolute ED visit volume but also in the proportion of patients requiring hospital admission and ICU care, indicating a marked rise in clinical acuity. The consistent pattern of increased utilization and severity in 2025 supports the hypothesis that patients presenting with OUD and opioid withdrawal required higher levels of care during this period, temporally coinciding with the emergence of medetomidine in the local illicit opioid supply.

Conclusion & Discussion: This retrospective analysis demonstrated significant increases in ED encounters, hospital admissions, and ICU utilization for patients presenting with primary diagnoses of OUD and opioid withdrawal in 2025 compared with 2023. ED visit volume and admission rates increased approximately 2-3-fold, and a much higher proportion of admitted patients required ICU-level care, indicating substantially increased acuity of OUD-related presentations.
Although these changes cannot be causally attributed to medetomidine given the lack of specific diagnostic codes and inability to link encounters to toxicology testing data, the temporal association with marked changes in the local drug supply is compelling. The emergence of medetomidine in fentanyl samples combined with published reports and clinical experience describing severe medetomidine withdrawal supports an association between medetomidine adulteration and increased healthcare utilization.
These findings have important implications for emergency, inpatient, and addiction treatment systems. Rising hospitalization and ICU needs may strain hospital capacity and challenge community-based and residential treatment programs that cannot provide high-acuity care. Limitations include observational design, reliance on administrative diagnoses, and lack of direct exposure confirmation. Further research is needed to define the direct impact of medetomidine, develop treatments deployable outside hospital settings, and improve tools to identify patients at highest risk for requiring hospital-based care.

References: 1. Allegheny County Health Department. (2025, August). Medetomidine: An adulterant of the illicit drug supply [Drug checking report]. University of North Carolina Street Drug Analysis Lab; Allegheny County Health Department. https://www.med.unc.edu/fammed/nctac/wp-content/uploads/sites/1256/2025/08/ACHD-Medetomidine-Brief-August-2025.pdf
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