Search

Introduction: Recent policy changes in Washington State presented a unique opportunity to pair evidence-based interventions with first responder services to combat increasing opioid overdoses. However, little is known about how these interventions should be implemented. In partnership with the Research with Expert Advisors on Drug Use team, a group of academically trained and community-trained researchers with lived and living experience of substance use, we examined facilitators and barriers to adopting leave-behind naloxone, field-based buprenorphine initiation, and HIV and hepatitis C virus (HCV) testing for first responder programs.Methods: Our team completed semi-structured, qualitative interviews with 32 first responders, mobile integrated health staff, and emergency medical services (EMS) leaders in King County, Washington, from February–May 2022. Semi-structured interviews were recorded, transcribed, and coded using an integrated deductive and inductive thematic analysis approach grounded in community-engaged research principles. We collected data until saturation was achieved. Data collection and analysis were informed by the Consolidated Framework for Implementation Research. Two investigators coded independently until 100% consensus was reached.Results: Our thematic analysis revealed several perceived facilitators (ie, tension for change, relative advantage, and compatibility) and barriers (ie, limited adaptability, lack of evidence strength and quality, and prohibitive cost) to the adoption of these evidence-based clinical interventions for first responder systems. There was widespread support for the distribution of leave-behind naloxone, although funding was identified as a barrier. Many believed field-based initiation of buprenorphine treatment could provide a more effective response to overdose management, but there were significant concerns that this intervention could run counter to the rapid care model. Lastly, participants worried that HIV and HCV testing was inappropriate for first responders to conduct but recommended that this service be provided by mobile integrated health staff.Conclusion: These results have informed local EMS strategic planning, which will inform roll out of process improvements in King County, Washington. Future work should evaluate the impact of these interventions on the health of overdose survivors.

Introduction: Opioid use is an epidemic that plagues the United States. Patients frequently present to the emergency department (ED) after opioid toxicity, which can lead to respiratory failure, apnea, and death. Although there is an effective antidote, naloxone, the current guidelines surrounding post-naloxone administration monitoring are loosely defined.Case Report: We present a case in which an individual was administered naloxone after an intentional opioid overdose and was monitored for four hours, as is standard in our institution. He remained in the ED for additional workup following this observation period and subsequently experienced signs of severe respiratory depression, requiring bag-valve-mask ventilation, naloxone, and admission. Had he been discharged, as is typical after a four-hour observation period, the consequences could have been fatal. We present multiple theories as to why his opioid toxidrome may have presented in a delayed manner, including ingestion of fentanyl analogues and variability in metabolization of both opioids and naloxone. We also explore alternative overdose antidote products approved by the US Food and Drug Administration, which may impact post overdose care.Conclusion: This case suggests that the correct amount of time to monitor patients after naloxone administration may be longer than originally thought. Our aim in this article was to further the discussion regarding the most appropriate observation period in cases of opioid toxicity.

Introduction: To expand access to naloxone, the state of Illinois implemented a standing order allowing registered pharmacies to dispense the drug without an individual prescription. To participate under the standing order, pharmacies were required to opt in through a formal registration process. In our study we aimed to evaluate the availability and price of naloxone at registered pharmacies.Methods: This was a prospective, de-identified, cross-sectional telephone survey. Trained interviewers posed as potential customers and used a standardized script to determine the availability of naloxone between February–December, 2019. The primary outcome was defined as a pharmacy indicating it carried naloxone, currently had naloxone in stock, and was able to dispense it without anindividual prescription.Results: Of 948 registered pharmacies, 886 (93.5%) were successfully contacted. Of those, 792 (83.4%) carried naloxone, 659 (74.4%) had naloxone in stock, and 472 (53.3%) allowed purchase without a prescription. Naloxone nasal spray (86.4%) was the formulation most commonly stocked. Chain pharmacies were more likely to carry naloxone (adjusted odds ratio [aOR] 3.16, 95% confidence interval [CI] 1.97–5.01, P < 0.01) and have naloxone in stock (aOR 2.72, 95% CI 1.76–4.20, P < 0.01), but no more likely to dispense it without a prescription. Pharmacies in higher population areas (aOR 0.99, 95% CI 0.99–0.99, P < 0.05) and rural areas adjacent to metropolitan areas (aOR 0.5, 95% CI 025–0.98, P < 0.05) were less likely to have naloxone available without a prescription. Associations of naloxone availability based on other urbanicity designations, overdose count, and overdose rate were not significant.Conclusion: Among pharmacies in Illinois that formally registered to dispense naloxone without a prescription, the availability of naloxone remains limited. Additional interventions may be needed to maximize the potential impact of a statewide standing order.

Introduction: People who use drugs in community settings are at risk of a fatal overdose, which can be mitigated by naloxone administered via bystanders. In this study we sought to investigate methods of estimating and tracking opioid overdose reversals by community members with take-home naloxone (THN) to coalesce possible ways of characterizing THN reach with a metric that is useful for guiding both distribution of naloxone and advocacy of its benefits.Methods: We conducted a scoping review of published literature on PubMed on August 15, 2022, using PRISMA-ScR protocol, for articles discussing methods to estimate THN reversals in the community. The following search terms were used: naloxone AND (“take home” OR kit OR “community distribution” OR “naloxone distribution”). We used backwards citation searching to potentially find additional studies. Overdose education and naloxone distribution program-based studies that analyzed only single programs were excluded.Results: The database search captured 614 studies, of which 14 studies were relevant. Backwards citation searching of 765 references did not reveal additional relevant studies. Of the 14 relevant studies, 11 were mathematical models. Ten used Markov models, and one used a system dynamics model. Of the remaining three articles, one was a meta-analysis, and two used spatial analysis. Studies ranged in year of publication from 2013–2022 with mathematical modeling increasing in use over time. Only spatial analysis was used with a focus on characterizing local naloxone use at the level of a specific city.Conclusion: Of existing methods to estimate bystander administration of THN, mathematical models are most common, particularly Markov models. System dynamics modeling, meta-analysis, and spatial analysis have also been used. All methods are heavily dependent upon overdose education and naloxone distribution program data published in the literature or available as ongoing surveillance data. Overall, there is a paucity of literature describing methods of estimation and even fewer with methods applied to a local focus that would allow for more targeted distribution of naloxone.

Introduction: Bystander provision of naloxone is a key modality to reduce opioid overdose-related death. Naloxone training courses are available, but no standardized program exists. As part of a bystander empowerment course, we created and evaluated a brief naloxone training module.Methods: This was a retrospective evaluation of a naloxone training course, which was paired with Stop the Bleed training for hemorrhage control and was offered to administrative staff in an office building. Participants worked in an organization related to healthcare, but none were clinicians. The curriculum included the following topics: 1) background about the opioid epidemic; 2) how to recognize the signs of an opioid overdose; 3) actions not to take when encountering an overdose victim; 4) the correct steps to take when encountering an overdose victim; 5) an overview of naloxone products; and 6) Good Samaritan protection laws. The 20-minute didactic section was followed by a hands-on session with nasal naloxone kits and a simulation mannequin. The course was evaluated with the Opioid Overdose Knowledge (OOKS) and Opioid Overdose Attitudes (OOAS) scales for take-home naloxone training evaluation. We used the paired Wilcoxon signed-rank test to compare scores pre- and post-course.Results: Twenty-eight participants completed the course. The OOKS, measuring objective knowledge about opioid overdose and naloxone, had improved scores from a median of 73.2% (interquartile range [IQR] 68.3%–79.9%) to 91.5% (IQR 85.4%–95.1%), P < 0.001. The three domains on the OOAS score also showed statistically significant results. Competency to manage an overdose improved on a five-point scale from a median of 2.5 (IQR 2.4–2.9) to a median of 3.7 (IQR 3.5–4.1), P < 0.001. Concerns about managing an overdose decreased (improved) from a median of 2.3 (IQR 1.9–2.6) to median 1.8 (IQR 1.5–2.1), P < 0.001. Readiness to intervene in an opioid overdose improved from a median of 4 (IQR 3.8–4.2) to a median of 4.2 (IQR 4–4.2), P < 0.001.Conclusion: A brief course designed to teach bystanders about opioid overdose and naloxone was feasible and effective. We encourage hospitals and other organizations to use and promulgate this model. Furthermore, we suggest the convening of a national consortium to achieve consensus on program content and delivery.

Objectives. To describe the current financial health of syringe services programs (SSPs) in the United States and to assess the predictors of SSP budget levels and associations with delivery of public health interventions. Methods. We surveyed all known SSPs operating in the United States from February to June 2022 (n = 456), of which 68% responded (n = 311). We used general estimating equations to assess factors influencing SSP budget size and estimated the effects of budget size on multiple measures of SSP services. Results. The median SSP annual budget was $100 000 (interquartile range = $20 159‒$290 000). SSPs operating in urban counties and counties with higher levels of opioid overdose mortality had significantly higher budget levels, while SSPs located in counties with higher levels of Republican voting in 2020 had significantly lower budget levels. SSP budget levels were significantly and positively associated with syringe and naloxone distribution coverage. Conclusions. Current SSP funding levels do not meet minimum benchmarks. Increased funding would help SSPs meet community health needs. Public Health Implications. Federal, state, and local initiatives should prioritize sustained SSP funding to optimize their potential in addressing multiple public health crises. (Am J Public Health. 2024;114(4):435-443. https://doi.org/10.2105/AJPH.2024.307583).

ImportanceThe incidence of opioid-associated out-of-hospital cardiac arrest (OA-OHCA) has grown from less than 1% of OHCA in 2000 to between 7% and 14% of OHCA in recent years; American Heart Association (AHA) protocols suggest that emergency medical service (EMS) clinicians consider naloxone in OA-OHCA. However, it is unknown whether naloxone improves survival in these patients or in patients with undifferentiated OHCA.ObjectiveTo evaluate the association of naloxone with clinical outcomes in patients with undifferentiated OHCA.Design, setting, and participantsRetrospective cohort study of EMS-treated patients aged 18 or older who received EMS treatment for nontraumatic OHCA in 3 Northern California counties between 2015 and 2023. Data were analyzed using propensity score-based models from February to April 2024.ExposureEMS administration of naloxone.Main outcomes and measuresThe primary outcome was survival to hospital discharge; the secondary outcome was sustained return of spontaneous circulation (ROSC). Covariates included patient and cardiac arrest characteristics (eg, age, sex, nonshockable rhythm, any comorbidity, unwitnessed arrest, and EMS agency) and EMS clinician determination of OHCA cause as presumed drug-related.ResultsAmong 8195 patients (median [IQR] age, 65 [51-78] years; 5540 male [67.6%]; 1304 Asian, Native Hawaiian, or Pacific Islander [15.9%]; 1119 Black [13.7%]; 2538 White [31.0%]) with OHCA treated by 5 EMS agencies from 2015 to 2023, 715 (8.7%) were believed by treating clinicians to have drug-related OHCA. Naloxone was administered to 1165 patients (14.2%) and was associated with increased ROSC using both nearest neighbor propensity matching (absolute risk difference [ARD], 15.2%; 95% CI, 9.9%-20.6%) and inverse propensity-weighted regression adjustment (ARD, 11.8%; 95% CI, 7.3%-16.4%). Naloxone was also associated with increased survival to hospital discharge using both nearest neighbor propensity matching (ARD, 6.2%; 95% CI, 2.3%-10.0%) and inverse propensity-weighted regression adjustment (ARD, 3.9%; 95% CI, 1.1%-6.7%). The number needed to treat with naloxone was 9 for ROSC and 26 for survival to hospital discharge. In a regression model that assessed effect modification between naloxone and presumed drug-related OHCA, naloxone was associated with improved survival to hospital discharge in both the presumed drug-related OHCA (odds ratio [OR], 2.48; 95% CI, 1.34-4.58) and non-drug-related OHCA groups (OR, 1.35; 95% CI, 1.04-1.77).Conclusions and relevanceIn this retrospective cohort study, naloxone administration as part of EMS management of OHCA was associated with increased rates of ROSC and increased survival to hospital discharge when evaluated using propensity score-based models. Given the lack of clinical practice data on the efficacy of naloxone in OA-OHCA and OHCA in general, these findings support further evaluation of naloxone as part of cardiac arrest care.

ObjectivesThe purpose of this study was to evaluate the impact of pharmacist-driven naloxone training of resident physicians as part of discharge prescribing from an inpatient psychiatric unit.MethodsThis is a prospective pilot study in which psychiatric resident physicians (N = 21) were educated on naloxone administration, prescribing, and counseling. A ten-question survey was designed and delivered immediately pre- and post-training to assess resident knowledge of and comfort with naloxone prescribing. Respondents were asked to rate ten statements on a scale from 1 to 5, with 1 corresponding to "strongly disagree" and 5 corresponding to "strongly agree." The primary objective was to evaluate the impact of training on prescriber knowledge and attitudes using the designed questionnaire. The secondary objective was to assess the difference in naloxone prescribing pre- and post-training implementation. Descriptive statistics and paired t-tests were conducted to assess statistical significance.ResultsPrior to training, 11 resident physicians (approximately 50%) agreed or strongly agreed that they felt knowledgeable about naloxone and approximately 70% (n = 15) felt confident identifying patients who would benefit from naloxone at discharge. Only 10% of resident physicians (n = 2) felt comfortable counseling patients on and administering naloxone during an overdose pre-training compared to 100% after training. Thirty-seven patients were discharged and counseled on naloxone use during the study period.ConclusionPharmacist-driven naloxone training significantly increased physician knowledge and comfort prescribing naloxone and resulted in an increase in naloxone prescriptions upon discharge from an inpatient psychiatric unit.

Background: The opioid crisis is a serious public health issue in Canada. There have been many surveillance programs and research studies on opioid-related emergency department (ED) visits at a national, provincial, regional or municipal level. However, no published studies have investigated the in-depth contexts surrounding opioid-related ED visits. In addition, few studies have examined injuries other than poisonings in those visits. The objective of this study is to investigate the contextual factors and co-occurrence of poisonings and injuries among the opioid-related ED visits in a Canadian sentinel surveillance system on injuries and poisonings from 2011 to 2022. Methods: This study used a mixed methods design. The data source was the Canadian Hospitals Injury Reporting and Prevention Program. We first selected all opioid-related ED visits during our study period and then identified the contextual factors through a content analysis of the combination of the narrative description and other variables in the patients' records. The contextual factors were organized into themes as opioid use context, social resource utilization, bystander involvement, and prior naloxone use. The opioid use context was used as a co-variable to examine the other themes and ED presentations (poisonings and other injuries). Quantitative descriptive approach was used to analyze all the contexts and ED presentations. Results: The most common opioid use context was non-prescribed opioid use without intention to cause harm, followed by self-poisoning, children's exposure, and medication error. Various rare contexts occurred. Paramedics participated in 27.9% of visits. Police and security guards were involved in 5.1% and 2.3% of visits, respectively. Child welfare or social workers were involved in 0.4% of visits. Bystanders initiated 18.9% of the ED visits. Naloxone use before arriving at the ED occurred in 23.4% of the visits with a variety of administrators. The majority of patients presented with poisoning effects, either with poisoning effects only or with other injuries or conditions. Conclusions: Our study has provided an in-depth analysis of contextual factors and co-occurrence of poisonings and injuries among opioid-related ED visits in Canada. This information is important for ED programming and opioid-related poisoning and injury intervention and prevention. [ABSTRACT FROM AUTHOR]

The ability of morphine to decrease cysteine transport into neurons by inhibition of excitatory amino acid transporter 3 (EAA3) may be a key molecular mechanism underlying the acquisition of physical and psychological dependence to morphine. This study examined whether co-administration of the cell-penetrant antioxidant D-thiol ester, D-cysteine ethyl ester (D-CYSee), with morphine, would diminish the development of physical dependence to morphine in male Sprague Dawley rats. Systemic administration of the opioid receptor antagonist, naloxone (NLX), elicited pronounced withdrawal signs (e.g., wet-dog shakes, jumps, rears, circling) in rats that received a subcutaneous depot of morphine (150 mg/kg, SC) for 36 h and continuous intravenous infusion of vehicle (20 µL/h, IV). The NLX-precipitated withdrawal signs were reduced in rats that received an infusion of D-CYSee, but not D-cysteine, (both at 20.8 µmol/kg/h, IV) for the full 36 h. NLX elicited pronounced withdrawal signs in rats treated for 48 h with morphine (150 mg/kg, SC), plus continuous infusion of vehicle (20 µL/h, IV) that began at the 36 h timepoint of morphine treatment. The NLX-precipitated withdrawal signs were reduced in rats that received a 12 h infusion of D-CYSee, but not D-cysteine, (both at 20.8 µmol/kg/h, IV) that began at the 36 h timepoint of morphine treatment. These findings suggest that D-CYSee may attenuate the development of physical dependence to morphine and reverse established dependence to the opioid in male Sprague Dawley rats. Alternatively, D-CYSee may simply suppress the processes responsible for NLX-precipitated withdrawal. Nonetheless, D-CYSee and analogues may be novel therapeutics for the treatment of opioid use disorders. [ABSTRACT FROM AUTHOR]

Rationale and objective: Avoidance of opioid withdrawal plays a key role in human opioid addiction. Here, we present a procedure for studying operant negative reinforcement in rats that was inspired by primate procedures where opioid-dependent subjects lever-press to prevent naloxone infusions. Methods: In Experiment 1, we trained rats (n = 30, 15 females) to lever-press to escape and then avoid mild footshocks (0.13–0.27 mA) for 35 days (30 trials/d). Next, we catheterized them and implanted minipumps containing methadone (10 mg/kg/day) or saline. We then paired (4 times, single session) a light cue (20-s) with a naloxone infusion (20 µg/kg, i.v) that precipitated opioid withdrawal. Next, we trained the rats to escape naloxone injections for 10 days (30 trials/d). Each trial started with the onset of the opioid-withdrawal cue. After 20-s, the lever extended, and an infusion of naloxone (1 to 2.2 µg/kg/infusion) began; a lever-press during an 11-s window terminated the withdrawal-paired cue and the infusion. In Experiment 2, we trained rats (n = 34, 17 females) on the same procedure but decreased the footshock escape/avoidance training to 20 days. Results: All rats learned to lever-press to escape or avoid mild footshocks. In both experiments, a subset, 56% (10/18) and 33% (8/24) of methadone-dependent rats learned to lever-press to escape naloxone infusions. Conclusions: We introduce an operant negative reinforcement procedure where a subset of opioid-dependent rats learned to lever-press to escape withdrawal-inducing naloxone infusions. The procedure can be used to study mechanisms of individual differences in opioid negative reinforcement-related behaviors in opioid-dependent rats. [ABSTRACT FROM AUTHOR]

Intranasal (IN) medications offer a safe non-invasive way to rapidly deliver drugs in situations where intravenous (IV) access and intramuscular (IM) administration is challenging or not feasible. In the prehospital setting, this can be an essential alternative in time critical situations including trauma management, seizures, and agitated patients. However, there is a paucity of evidence summarizing its efficacy in this environment. This systematic review aims to assess the current evidence supporting the use of IN medicine (midazolam, ketamine, fentanyl, morphine, glucagon, and naloxone) in the prehospital setting alone. A systematic literature search (PROSPERO CRD42023440713) of PubMed, Web of Science, OVID Medline, "Cochrane Central Register of Controlled Trials," Cochrane reviews and Embase was performed from inception to June 2023 to identify studies where IN medications were administered to patients in the prehospital setting. All randomized controlled trials, observational cohort studies, case series, and case reports were included. Papers not written in English, review articles, abstracts, and non-published data (including letters to the editor) were excluded. The methodological quality of the included studies was interpreted using the Cochrane risk of bias tool and rated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. No funding was received. From 4818 studies, 39 were included (seven for midazolam, five for ketamine, twelve for fentanyl, one for diamorphine, two for glucagon, and twelve for naloxone). A total of 24,097 patients were treated with IN medications across all the studies. There were five moderate quality, four low quality, and thirty very low quality studies. The potential efficacy of IN fentanyl and ketamine was demonstrated consistently throughout the studies with less clear evidence for midazolam, morphine, glucagon, and naloxone. This review was severely limited by the study quality, with most studies demonstrating "high concerns" for bias. Prehospital IN medication administration has wide-ranging potential, particularly for administering analgesia. There are likely to be certain populations, for example, pediatrics, that will benefit the most, although conclusions are limited by the quality of evidence currently available. We encourage additional research in this area, particularly with robust prospective double-blind RCTs. [ABSTRACT FROM AUTHOR]

Since April 2019, CA Bridge has worked with emergency departments (EDs) in diverse geographic and emergency care settings across California to scale up low-threshold buprenorphine access, patient navigation programs, harm reduction services, and take-home naloxone. Between April 2019 and June 2023, 268 (81.0%) of 331 acute care hospitals in California received funding and technical assistance from CA Bridge and completed data reporting. These hospitals provided navigation services during 279 025 patient encounters and gave patients buprenorphine in 89 549 ED visits. (Am J Public Health. 2024;114(9):874–878. https://doi.org/10.2105/AJPH.2024.307710) [ABSTRACT FROM AUTHOR]

Purpose: Mu-opioid receptors (MORs) are widely expressed in the central nervous system (CNS), peripheral organs, and immune system. This study measured the whole body distribution of MORs in rhesus macaques using the MOR selective radioligand [11C]carfentanil ([11C]CFN) on the PennPET Explorer. Both baseline and blocking studies were conducted using either naloxone or GSK1521498 to measure the effect of the antagonists on MOR binding in both CNS and peripheral organs. Methods: The PennPET Explorer was used for MOR total-body PET imaging in four rhesus macaques using [11C]CFN under baseline, naloxone pretreatment, and naloxone or GSK1521498 displacement conditions. Logan distribution volume ratio (DVR) was calculated by using a reference model to quantitate brain regions, and the standard uptake value ratios (SUVRs) were calculated for peripheral organs. The percent receptor occupancy (%RO) was calculated to establish the blocking effect of 0.14 mg/kg naloxone or GSK1521498. Results: The %RO in MOR-abundant brain regions was 75–90% for naloxone and 72–84% for GSK1521498 in blocking studies. A higher than 90% of %RO were observed in cervical spinal cord for both naloxone and GSK1521498. It took approximately 4–6 min for naloxone or GSK1521498 to distribute to CNS and displace [11C]CFN from the MOR. A smaller effect was observed in heart wall in the naloxone and GSK1521498 blocking studies. Conclusion: [11C]CFN total-body PET scans could be a useful approach for studying mechanism of action of MOR drugs used in the treatment of acute and chronic opioid use disorder and their effect on the biodistribution of synthetic opioids such as CFN. GSK1521498 could be a potential naloxone alternative to reverse opioid overdose. [ABSTRACT FROM AUTHOR]

Background: Opioids kill more people than any other class of drug. Naloxone is an opioid antagonist which can be distributed in kits for peer administration. We assessed the feasibility of implementing a Take-home Naloxone (THN) intervention in emergency settings, as part of designing a definitive randomised controlled trial (RCT). Methods: We undertook a clustered RCT on sites pairing UK Emergency Departments (ED) and ambulance services. At intervention sites, we recruited emergency healthcare practitioners to supply THN to patients presenting with opioid overdose or related condition, with recruitment across 2019–2021. We assessed feasibility of intervention implementation against four predetermined progression criteria covering site sign up and staff training; identification of eligible patients; issue of THN kits and Serious Adverse Events. Results: At two intervention sites, randomly selected from 4, 299/687 (43.5%) clinical staff were trained (ED1 = 107, AS1 = 121, ED2 = 25, AS2 = 46). Sixty THN kits were supplied to eligible patients (21.7%) (n: ED1 = 36, AS1 = 4, ED2 = 16, AS2 = 4). Across sites, kits were not issued to eligible patients on a further 164 occasions, with reasons reported including: staff forgot (n = 136), staff too busy (n = 15), and suspected intentional overdose (n = 3), no kit available (n = 2), already given by drugs nurse (n = 4), other (n = 4). Staff recorded 626 other patients as ineligible but considered for inclusion, with reasons listed as: patient admitted to hospital (n = 194), patient absconded (n = 161) already recruited (n = 64), uncooperative or abusive (n = 55), staff not trained (n = 43), reduced consciousness level (n = 41), lack of capacity (n = 35), patient in custody (n = 21), other (n = 12). No adverse events were reported. Conclusion: Staff and patient recruitment were low and varied widely by site. This feasibility study did not meet progression criteria; a fully powered RCT is not planned. Trial Registration: ISRCTN13232859 (Registered 16/02/2018). [ABSTRACT FROM AUTHOR]

Background: The United States' (US) opioid overdose epidemic has evolved into a combined stimulant/opioid epidemic, a pattern driven in part by mitigating opioid overdose risk, variable substance availability, and personal preferences. This study aimed to investigate the association between self-reported substance preference (heroin or methamphetamine) and behavioral/health outcomes among individuals who used both heroin and methamphetamine in the rural US. Methods: The Rural Opioid Initiative is a consortium of 8 research cohorts from 10 states and 65 rural counties that recruited individuals reporting past 30-day injection of any substance or opioid substance use by any route from 1/2018 to 3/2020. Analyses were restricted to participants ⩾18 years, who self-reported either heroin or methamphetamine as their preferred substance and past 30-day use of both heroin and methamphetamine. We examined cross-sectional associations between preferred substance (heroin versus methamphetamine) and behavioral and health outcomes using random effects meta-analysis with adjusted regression models. Results: Among 1239 participants, 61% (n = 752) reported heroin as their preferred substance. Adjusting for age, sex, and race/ethnicity, methamphetamine preference was associated with lower prevalence ratios for current naloxone possession (adjusted prevalence ratio [aPR] = 0.68; 95% Confidence Interval [95% CI] = 0.59-0.78; P -value ⩽.001), of ever being told they had the hepatitis C virus (HCV; aPR = 0.72; 95% CI: 0.61-0.85; P -value ⩽.001) and a personal history of overdose (aPR = 0.81; 95% CI = 0.73-0.90; P -value ⩽.001). Conclusion: In our study analyzing associations between preferred substance and various behavioral and health outcomes amongst people who use both heroin and methamphetamine, a majority of participants preferred heroin. Methamphetamine preference was associated with lower prevalence of naloxone possession, ever being told they had HCV, and prior history of an overdose. This study underscores the need for targeted harm reduction services for people who prefer methamphetamine in rural areas. [ABSTRACT FROM AUTHOR]