"NYC engaged in a series of discussions with local, state, and federal stakeholders to gauge the viability of opening OPCs in the absence of clear authorization. Strong political engagement of local stakeholders—including the New York City Police Department (NYPD), district attorneys, and local elected officials—was critical to not only mitigate risks of local enforcement against OPC operations but also to ensure successful service provision. Education and engagement of city agencies and elected officials have been ongoing since the release of the feasibility report in 2018.

"In 2021, NY State and the USA elected executive branch leaders who publicly supported harm reduction as a public health approach to reducing overdose deaths. In April 2021, the Biden administration explicitly listed “enhancing evidence-based harm reduction efforts” as a drug policy priority for its first year in office, which NYC interpreted as potentially aligned with the concept of OPCs.

"A xylazine-associated death was defined as a positive postmortem xylazine serum toxicology test result in an unintentional, undetermined, or pending intent substance-related death during January 2017–October 2021. Routine postmortem tests were conducted for other substances including fentanyl, fentanyl analogs, cocaine, and naloxone. Xylazine testing is standard in Cook County for suspected drug overdose deaths.

"Xylazine, an alpha-2 receptor agonist, is used in veterinary medicine as a sedative and muscle relaxant; it is not approved for use in humans. However, reports of adulteration of illicit opioids with xylazine have been increasing in the United States (1–3). In humans, xylazine can cause respiratory depression, bradycardia, and hypotension (4).

"In June 2020, the presence of xylazine, a veterinary sedative, was first detected as an active cut in heroin/fentanyl MADDS samples but in very low or trace quantities from 2 sites. By fall 2020, the ratio of xylazine to other active drugs had increased, and by the end of the year, xylazine was identified in 6.3% of MADDS samples (13.4% of fentanyl, 22.2% of heroin) and detected at all sites. At the close of 2020, some samples were found to contain more xylazine than fentanyl (eg, https://DrugsData.org/9661).

"Globally, community drug checking programs (CDCPs) allow people to submit drug samples for chemical analysis.

"The Massachusetts Drug Supply Data Stream (MADDS) is the country's first statewide community drug checking program. Founded on public health-public safety partnerships, MADDS collects remnant drug packaging and paraphernalia with residue from people who use drugs and noncriminal samples from partnering police departments. MADDS tests samples using simultaneous immunoassay fentanyl test strips, Fourier-transform infrared spectrometry (FTIR), and off-site laboratory testing by gas chromatography-mass spectrometry (GC/MS).

"Xylazine is currently not a scheduled substance under the United States Controlled Substances Act, though some efforts are underway to change this (Drug Enforcement Administration, 2021; Murphy, n.d.).

"We summarize longitudinal, recent, and geographically specific evidence describing how xylazine is increasingly implicated in overdose deaths in jurisdictions spanning all major US regions and link it to detailed ethnographic observations of its use in Philadelphia open-air narcotics markets. Xylazine presence in overdose deaths grew exponentially during the observed period, rising nearly 20-fold between 2015 and 2020.

"In overdose data from 10 jurisdictions – representing all four major US census regions – xylazine was found to be increasingly present in overdose mortality (Fig. 1). The highest prevalence was observed in Philadelphia, (with xylazine present in 25.8% of overdose deaths in 2020), followed by Maryland (19.3% in 2021) and Connecticut (10.2% in 2020). In 2021, xylazine prevalence also grew substantially in Jefferson County, Alabama, reaching 8.4% of overdose fatalities.