Notes from the Field: Overdose Deaths Involving Para-fluorofentanyl — United States, July 2020–June 2021

Fluorofentanyl and novel synthetic opioids in accidental overdose deaths

One of the quickest-growing subclasses of novel psychoactive substances is novel synthetic opioids (NSOs), which are categorized as fentanyl analogs (fentalogs) or nonfentanyl opioids that bind to the mu-opioid receptor. Increased detections of NSOs have been observed in the USA. However, limited information on their prevalence outside of the East Coast is available. This study details the prevalence of NSOs, specifically fluorofentanyl, in the biological and drug paraphernalia specimens of accidental overdose deaths in San Francisco in 2022. A recently developed and validated liquid chromatography with tandem mass spectrometry method was utilized for the analysis of >250 NSOs. Out of the 649 accidental overdose deaths in 2022, 617 cases were available for blood analysis, with at least 1 NSO detected in 48 cases (7.8%). Fentalogs were detected in all 48 cases, with fluorofentanyl being detected in 40 cases. In postmortem femoral blood, estimated concentrations of fluorofentanyl ranged from 0.1 to 8.9 ng/mL, and 0.05 to 85 ng/mL in urine. Polysubstance use with NSO was seen with fentanyl (89.6%), methamphetamine (70.8%), cocaine (33.3%), and heroin (18.8%). NSOs, mainly fluorofentanyl, were observed in matched drug paraphernalia. This report documents the migration of fluorofentanyl to the West Coast, specifically California.

The Detection of Xylazine in Tijuana, Mexico: Triangulating Drug Checking and Clinical Urine Testing Data

Introduction

Xylazine is a veterinary anesthetic increasingly present alongside illicit fentanyl in the US and Canada, presenting novel health risks. Although xylazine remains less common in the Western US, Mexican border cities serve as key trafficking hubs and may have higher prevalence of novel substances, but surveillance has been limited.

Methods

We examined deidentified records from the Prevencasa harm reduction clinic in Tijuana, describing urine and paraphernalia testing from patients reporting using illicit opioids within 24 hr. Xylazine (two types), fentanyl, opiate, methamphetamine, amphetamine, benzodiazepine, and nitazene test strips were used to test urine and paraphernalia samples. Paraphernalia samples were also analyzed with mass spectrometry.

Results

The study consisted of 23 participants that provided both urine and paraphernalia samples. Of the participants studied, 100 %, 91.3 %, and 69.6 % reported using China White/fentanyl, methamphetamine, and tar heroin, respectively. The mean age was 41.7 years, 95.7 % were male, 65.2 % were unhoused, and 30.4 % had skin wounds at the time of sample collection.Xylazine positivity in urine, for the two types used, was 82.6 % and 65.2 %. For paraphernalia testing, the xylazine positivity was 65.2 % and 47.8 %. Confirmatory testing of paraphernalia samples by mass spectrometry indicated a 52.2 % xylazine positivity. This testing also revealed positivity rates for fentanyl (73.9 %), fluorofentanyl (30.4 %), tramadol (30.4 %), and lidocaine (30.4 %).The mass spectrometry results suggest lidocaine triggered n = 3 and n = 0 false positives among the xylazine test strip types. A total of n = 0 and n = 1 false negatives were also observed.

Discussion

Xylazine is present on the U.S.-Mexico border, requiring public health intervention. High lidocaine positivity complicates the clinical detection of xylazine via testing strips. Xylazine was found to be more prevalent in urine than in paraphernalia samples. Confirmatory urine studies are needed to better understand possible complications of using test strips for toxicological testing.

National and regional trends in fentanyl seizures in the United States, 2017-2023

BACKGROUND

Rates of synthetic opioid-related deaths over time and across regions have been compared within the US, but other indicator data could help inform prevention and harm reduction as well. We compared regional trends in fentanyl seizures to examine potential shifts in illicit fentanyl availability.

METHODS

Annual trends in fentanyl seizures were examined using data from High Intensity Drug Trafficking Areas for the US overall and by region from 2017 through 2023. Multiple measures included the number of seizures, the number of powder seizures, the number of pill seizures, the total weight of seizures, the number of pills seized, and the percentage of the number of pill seizures relative to the number of total seizures.

RESULTS

The percentage of seizures in pill form in the US increased from 10.3 % in 2017 to 49.0 % in 2023 (adjusted annual percentage change [AAPC]=25.2, 95 % CI: 17.6, 33.2), with 115.6 million individual pills seized in 2023. Pill weight related to total seizure weight also increased from 0.4 % to 54.5 % (AAPC=112.6, 95 % CI: 78.6, 153.2). In 2023, the plurality of seizures was in the West, in seven out of eight of our measures, with 77.8 % of seizures in the West being in pill form. Although the Midwest had lower prevalence of seizures than the West, there were notable increases in the Midwest in the number of pill seizures (AAPC=142.2, 95 % CI: 91.9, 205.8) and number of pills seized (AAPC=421.0, 95 % CI: 272.7, 628.4). Total weight of fentanyl seized increased the most in the West (AAPC=84.6, 95 % CI: 72.3, 97.8).

CONCLUSIONS

The number and size of fentanyl seizures is increasing in the US, with the majority of seizures, especially in pill form, in the West. Continued monitoring of regional shifts in the fentanyl supply can help inform targeted prevention and public health response.

Adulterants present in the San Diego county fentanyl supply: a laboratory analysis of seized law enforcement samples

BACKGROUND

The opioid overdose crisis is one of the worst public health crises ever to face the US and emerging evidence suggests its effects are compounded by the presence of drug adulterants. Here we report our efforts to characterize the adulterants present within the local fentanyl supply of San Diego County, obtained from undifferentiated drug samples seized by local law enforcement over the calendar year 2021.

METHODS

Thirty-two participating local law enforcement agencies across San Diego submitted 4838 unknown individual illicit drug samples (total of 312 kg) to the San Diego County Sheriff's Department Regional Crime Laboratory for identification.

RESULTS

Qualitative analysis of these samples via FTIR and GC-MS identified methamphetamine (38.7%), fentanyl (20.8%), diacetylmorphine (heroin) (10.2%), codeine (5.8%) and alprazolam (4.3%) as the most common illicit substances and the presence of 52 unique adulterants. The most common adulterants included 4-methylaminoantipyrine (4-MAAP) (10.9%), mannitol (9%), acetaminophen (8.5%), methamphetamine (4.2%), diacetylmorphine (heroin) (3.6%), tramadol (1.9%), and xylazine (1.7%). Several additional pharmacologically active adulterants and contaminants of interest were also identified.

CONCLUSION

This analysis is vital for public health use and harm reduction efforts at the level of the individual consumer. Continued direct surveillance of the drug supply is necessary for the detection of potentially harmful adulterants that may pose serious threats to the public.

"I Don't Go Overboard": Perceptions of Overdose Risk and Risk Reduction Strategies among People Who Use Drugs in Rhode Island

Background: North America experiencing an unprecedented overdose epidemic, with data estimating almost 110,000 overdose deaths occurring in 2022 in the United States (US). To address fatal overdoses in the US, community organizations and local health departments in some jurisdictions have expanded community distribution of naloxone, and increased overdose prevention education, and other harm reduction supplies and services (e.g., fentanyl test strips, drug checking programs) to reduce harm for people who use drugs (PWUD). Objectives: Understanding how PWUD manage overdose risk within the context of these expanded services is important for ensuring public health services are meeting their needs. Semi-structured qualitative interviews were conducted with 25 PWUD who were accessing harm reduction services in Rhode Island. Data were imported into NVivo where they were coded and analyzed thematically. Results: Our findings demonstrate the complexity of managing overdose risk in the context of a fentanyl drug supply. While most participants were concerned about overdosing, they sought to manage overdose risk through their own harm reduction practices (e.g., testing their drugs, going slow) and drug purchasing dynamics, even when using alone. Conclusions: Study findings point to the need to implement and scale-up community-level interventions to better support PWUD within the context of the current US overdose crisis.

Trends in Self-Reported Fentanyl and Other Illicit Substance Use in South Carolina Emergency Department Patients, 2020-2022

BACKGROUND

Opioid-involved deaths are continuing to increase across the United States, exceeding 100,000 for the first time in 2021. Contamination with, and intentional use of, synthetic opioids such as fentanyl are a major driver of this increase. Utilizing self-report substance use data of patients being treated in the emergency department (ED) can be useful to determine which substances patients are intentionally seeking.

OBJECTIVES

1) Examine changes in self-reported illicit substance use (including fentanyl) over time; 2) Examine changes in the co-occurrence of self-reported fentanyl with other illicit substance use over time.

METHODS

All patients presenting to the study EDs that answered anything other than "never" on the National Institute on Drug Abuse Quick Screen and were seen by a peer recovery specialist in the ED between July 1, 2020 and December 31, 2022 were included for analysis. The substance of use as reported by each patient was recorded by the peer recovery specialist. Differences in substance use by type over time were examined using chi-squared tests of proportions.

RESULTS

There were 7568 patients that met inclusion criteria. Self-reported fentanyl (1760%; p < 0.0001) and cocaine (82%; p = 0.034) use increased, whereas heroin use (16%; p < 0.0001) decreased.

CONCLUSIONS

Self-reported fentanyl and cocaine use has increased significantly in South Carolina ED patients between 2020 and 2022. Given the high morbidity and mortality associated with fentanyl and fentanyl analog use, further measures to identify these patients and provide harm reduction and treatment from the ED setting are warranted.

Comparative toxicology of syringe exchange and postmortem blood samples in the District of Columbia: Trends and affinity analysis

This cross-sectional analysis aimed to understand the similarities and differences between drugs detected in syringes collected from syringe service providers in the District of Columbia and fatal overdose deaths captured by the State Unintentional Drug Overdose Reporting System. Substance exposures for these fatal and non-fatal drug use outcomes have not been previously compared. Substance distributions were examined and a paired significance test was used to compare changes over time. Affinity analysis was employed to reveal substance co-occurrences. Between September 2020 and September 2022, 1,118 postmortem blood samples (PBSs) and 3,646 syringes exchange samples (SESs) were processed, with fatal overdoses increasing 24.1%. Polysubstance use was more commonly found in postmortem blood (82.5%) than in syringe samples (48.6%). Of samples containing opioids, 94.8% of blood samples and 86.3% of syringes contained fentanyl, fentanyl analogs or fentanyl precursors/metabolites. PBSs had double the frequency of co-occurring stimulants and opioids (43.9%) as SESs (21.8%). Major changes in occurrence frequency over time were found for opioid and stimulant exposure in both groups, especially in the increased occurrence of fluorofentanyl (>400%), methamphetamine (>90%) and xylazine (>60%), while the incidence of fentanyl, heroin and metabolite morphine declined. These results indicate that while fatal use and syringe exchange populations have distinct substance exposures, which may contribute to differences in mortality rate, their substance distributions have similar change magnitudes. This study highlights the utility of using multiple data sources to provide a comprehensive description of drug use patterns and discusses the limitations in reporting data from each source.

Fentanyl analog structure-activity relationships demonstrate determinants of diverging potencies for antinociception and respiratory depression

Opioid overdoses, particularly those involving fentanyl-related substances (FRS), present a significant public health challenge in the United States. This structure-activity relationship (SAR) study evaluated the relationship between the chemical structure of seventeen FRS and their in vivo mu-opioid-receptor (MOR) mediated effects. SAR evaluations included fluorine substitutions on the aniline or phenethyl ring and variations in N-acyl chain length. Adult male Swiss Webster mice were administered fluorinated regioisomers of fentanyl, butyrylfentantyl and valerylfentanyl, and compared to MOR standards including morphine, buprenorphine, and fentanyl to determine if they would elicit prototypical opioid-like effects including hyperlocomotion (open-field test), antinociception (warm-water tail-withdrawal test), and hypoventilation (whole-body plethysmography test). To determine if the MOR was the pharmacological mechanism responsible for these effects, naltrexone or naloxone pretreatments were administered to evaluate their actions on FRS-induced antinociception and hypoventilation. There were three main findings. First, FRS elicited hyperlocomotion, antinociception, and hypoventilation in mice to varying degrees, similar to prototypical MOR standards. Second, the rank order of potencies for hypoventilatory effects of FRS were different for each series including FRS with increasing N-acyl chain length (i.e., acetylfentanyl, fentanyl, butyrylfentanyl, valerylfentanyl, hexanoylfentanyl), phenethyl-fluorinated regioisomers (e.g., 2'-fluorofentanyl, 3'-fluorofentanyl, 4'-fluorofentanyl), and aniline-fluorinated regioisomers (e.g., ortho-fluorofentanyl, meta-fluorofentanyl, para-fluorofentanyl). Third, the degree of separation in potencies observed for the antinociceptive and hypoventilatory effects of these drugs did not always follow that which was observed for their antinociceptive and hyperlocomotor effects. This study clarifies the in vivo activities for these FRS and elucidates a SAR for MOR-mediated effects among structural isomers.

Land-System Changes and Migration Amidst the Opium Poppy Collapse in the Southern Highlands of Oaxaca, Mexico (2016-2020)

For decades, Mexico has been one of the major illegal opium poppy cultivation countries in the world. In 2017-2018 the price of the opium gum dropped abruptly to a historical low, causing a sudden collapse of production. We analyze the dynamics of rural land systems amid this price collapse through a multi-site approach in three neighboring municipalities in the Southern Highlands of the state of Oaxaca, Mexico. We use medium-scale spatial resolution satellite imagery for a quantitative assessment in a five-year period (2016-2020), complemented by secondary data and structured/semi-structured interviews with poppy growers and other key informants. Findings show that all three municipalities experienced pronounced declines in the areas of overall cultivated agricultural land immediately after the poppy price collapsed (2017-2018). However, there is a clear contrast among municipalities in how these areas recovered the following years (2019-2020). We identify three differentiating factors that explain this contrast in land-system trajectories: different levels of extreme poverty, livelihood diversification, and geographic isolation associated to (trans)national migration networks. These findings contribute to the analysis of the dynamic relationships among rural land systems, local resource management (including agrobiodiversity), and economic globalization involving illegal crop-commodity cultivation and migration, particularly in Latin America.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10745-022-00388-4.