Estimating the impact of stimulant use on initiation of buprenorphine and extended-release naltrexone in two clinical trials and real-world populations

A cross-sectional study of differences in medication for opioid use disorder receipt among pregnant people enrolled in Medicaid in Oregon, United States

BACKGROUND AND AIMS

Medication is the gold standard to support a healthy pregnancy for pregnant people with opioid use disorder (OUD). This study measured inequities and differences in OUD medication treatment among pregnant people in Oregon, USA.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

Our study population consisted of Medicaid enrollees across the US state of Oregon who had at least one live hospital birth between 2012 and 2020 and one diagnosis of OUD prenatally (n = 4363). We measured differences in demographic characteristics (age, race, ethnicity, location) among those with and without medication for OUD in the prenatal through 3-months postpartum period (any medication use, and by type), and compared exclusive methadone versus buprenorphine receipt. We report unadjusted and adjusted odds ratios.

FINDINGS

Adjusted odds ratios for medication for OUD were lower among American Indian/Alaska Native pregnant people compared with White pregnant people [adjusted odds ratio (aOR) 0.59 (95% confidence interval [CI] = 0.42, 0.83)], younger pregnant people compared with those aged 30-34 years [aOR, ages 15-19: 0.1 (95 CI = 0.06, 0.18); aOR, ages 20-24: 0.58 (95 CI = 0.49, 0.69)] and rural pregnant people compared with those in urban communities [aOR 0.58 (95 CI = 0.5-0.67)]. Rural pregnant people with OUD also had lower odds of methadone receipt [aOR 0.23 (95 CI = 0.17, 0.3)] and higher odds of buprenorphine receipt [aOR 3.99 (95 CI = 2.97, 5.35)] than other people in this study. Among those who received medication, Black pregnant people had increased odds of receiving methadone compared with buprenorphine [aOR 2.09 (95 CI = 1.1-3.97)].

CONCLUSIONS

In Oregon, USA, inequities in receipt of any medication for opioid use disorder were observed among pregnant people who identified as American Indian or Alaska Native, younger than 25, and living in rural communities. Black pregnant people in Oregon, USA, were more likely to receive methadone than buprenorphine.

Longitudinal patterns and predictors of opioid and stimulant use initiation and cessation among female sex workers living with HIV in South Africa

Female sex workers (FSW) are disproportionately impacted by HIV and substance use. Substance use has been linked to poor HIV treatment outcomes, necessitating exploration of substance use patterns - including polysubstance use - and predictors among FSW living with HIV. Data were obtained for 777 FSW living with HIV who were not virally suppressed and previously randomized to Siyaphambili, a trial of HIV treatment support strategies implemented through TB HIV Care in eThekwini, South Africa. FSW were asked about recent marijuana, opioid, stimulant, and hazardous alcohol use at enrollment and semi-annually for 18 months from June 2018-January 2022. We estimated incidence of substance use initiation/cessation post-enrollment and used Kaplan-Meier plots and lasagna plots to visualize trends. Cox proportional hazards models assessed baseline predictors of substance use initiation/cessation. Overall, 454 FSW (58.4 %) reported any opioid and/or stimulant use. Prior visit hazardous alcohol use (aHR: 0.20, 95 % CI 0.09-0.41) and prior-visit stimulant use (aHR: 2.80, 95 % CI 1.23-6.37) were negatively and positively associated with opioid initiation, respectively. Prior visit marijuana use (aHR: 1.75, 95 % CI 1.11-2.75) and opioid use (aHR: 5.31, 95 % CI 3.32-8.51) were positively associated with stimulant initiation. We found a high prevalence of substance use among FSW living with HIV that was dynamic over time, including a shared relationship between opioid and stimulant use that suggests intertwined substance use. Further investigation into the impact of polysubstance use patterns on success of HIV support strategies is needed to inform HIV treatment and harm reduction programming.

Systematic review of applied transportability and generalizability analyses: A landscape analysis

Transportability and generalizability analysis are novel causal inference methods that quantitatively assess external validity. Currently, it is unclear how these analyses are applied in practice. To characterize applications and methods, we conducted a landscape analysis of applied transportability and generalizability analyses using a systematic literature search of PubMed, CINAHL and Embase supplemented with hand-searches. We identified 68 publications describing transportability and generalizability analyses conducted with 83 unique source-target dataset pairs and reporting 99 distinct analyses. The majority of source and target datasets were collected in the US (n = 63/83, 75.9 %; and n = 59/83, 71.1 %, respectively). These methods were most often applied to transport RCT findings to observational studies (n = 38/83; 45.8 %), or to another RCT (n = 20/83; 24.1 %). Several studies used transportability analysis outside the standard application, for example to identify effect modifiers or calibrate measurements within an RCT. Methods that used weights and individual-level patient data were most common (n = 56/99, 56.5 %; n = 80/83, 96.4 %, respectively). Reporting quality varied across studies. Transportability analysis has a wide range of applications including supporting decision-making by improving evidence relevance and improving trial design by identifying contextual effect modifiers and calibrating outcome measurements. Efforts are needed to standardize analysis and reporting of these methods to improve transparency and uptake.

Use of transportability methods for real-world evidence generation: a review of current applications

Aim: To evaluate how transportability methods are currently used for real-world evidence (RWE) generation to inform good practices and support adoption and acceptance of these methods in the RWE context. Methods: We conducted a targeted literature review to identify studies that transported an effect estimate of the clinical effectiveness or safety of a biomedical exposure to a target real-world population. Records were identified from PubMed-indexed articles published any time before 25 July 2023 (inclusive). Two reviewers screened abstracts/titles and reviewed the full text of candidate studies to identify the final set of articles. Data on the therapeutic area, exposure(s), outcome(s), original and target populations and details of the transportability analysis (e.g., analytic method used, estimate transported, stated assumptions) were abstracted from each article. Results: Of 458 unique records identified, six were retained in the final review. Articles were published during 2021-2023, focused on the US/Canada context, and covered a range of therapeutic areas. Four studies transported an RCT effect estimate, while two transported effect estimates derived from real-world data. Almost all articles used weighting methods to transport estimates. Two studies discussed all transportability assumptions, and one evaluated the likelihood of meeting all assumptions and the impact of potential violations. Conclusion: The use of transportability methods for RWE generation is an emerging and promising area of research to address evidence gaps in settings with limited data and infrastructure. More transparent and rigorous reporting of methods, assumptions and limitations may increase the use and acceptability of transportability for producing robust evidence on treatment effectiveness and safety.

Respiratory Depression Associated with Opioids: A Narrative Review

OPINION

All opioids have a risk of causing respiratory depression and reduced cerebral circulation. Fentanyl has the greatest risk of causing both. This is particularly a concern when combined with illicit opioids such as diamorphine (also known as heroin). Fentanyl should not be used as a frontline potent opioid due its significant risks. Buprenorphine, a schedule III opioid, morphine, or hydromorphone is preferred, followed by oxycodone, which has a significant risk of abuse relative to buprenorphine and morphine. Although all opioids were equally effective in producing analgesia, the relative safety of each opioid is no longer a secondary concern when prescribing. In the face of an international opioid epidemic, clinicians need to choose opioid analgesics safely, wisely, and carefully.

Endogenous opiates and behavior: 2023

This paper is the forty-sixth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2023 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug and alcohol abuse (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Reconsidering the usefulness of long-term high-dose buprenorphine

Buprenorphine has been successfully used for decades in the treatment of opioid use disorder, yet there are complexities to its use that warrant attention to maximize its utility. While the package insert of the combination product buprenorphine\naloxone continues to recommend a maximum dose of 16 mg daily for maintenance, the emergence of fentanyl and synthetic analogs in the current drug supply may be limiting the effectiveness of this standard dose. Many practitioners have embraced and appropriately implemented novel practices to mitigate the sequelae of our current crisis. It has become common clinical practice to stabilize patients with 24 - 32 mg of buprenorphine daily at treatment initiation. Many of these patients, however, are maintained on these high doses (>16 mg/d) indefinitely, even after prolonged stability. Although this may be a necessary strategy in the short term, there is little evidence to support its safety and efficacy, and these high doses may be exposing patients to more complications and side effects than standard doses. Commonly known side effects of buprenorphine that are likely dose-related include hyperhidrosis, sedation, decreased libido, constipation, and hypogonadism. There are also complications related to the active metabolite of buprenorphine (norbuprenorphine) which is a full agonist at the mu opioid receptor and does not have a ceiling on respiratory suppression. Such side effects can lead to medical morbidity as well as decreased medication adherence, and we, therefore, recommend that after a period of stabilization, practitioners consider a trial of decreasing the dose of buprenorphine toward standard dose recommendations. Some patients' path of recovery may never reach this stabilization phase (i.e., several months of adherence to medications, opioid abstinence, and other clinical indicators of stability). Side effects of buprenorphine may not have much salience when patients are struggling for survival and safety, but for those who are fortunate enough to advance in their recovery, the side effects become more problematic and can limit quality of life and adherence.

Stimulant Drugs and Stimulant Use Disorder

The authors aim to summarize several key points of stimulant drugs and stimulant use disorder, including their indications, short-term and long-term adverse effects, current treatment strategies, and association with opioid medications. The global prevalence of stimulant use has seen annual increase in the last decade. Multiple studies have shown that stimulant use and stimulant use disorder are associated with a range of individual and public health issues. Stimulant misuse has led to a significant increase of overdose deaths in the United States.

Risks of returning to opioid use at treatment entry and early in opioid use disorder treatment: Role of non-opioid substances

OBJECTIVE

Patients in treatment with medications for opioid use disorder (MOUD) often report use of other substances in addition to opioids. Few studies exist that examine the relationship between use at treatment entry and early non-opioid use in opioid treatment outcome.

METHODOLOGY

We combined and harmonized three randomized, controlled MOUD clinical trials from the National Institutes of Drug Abuse (NIDA) Clinical Trials Network (CTN) (N=2197) and investigated the association of non-opioid substance use at treatment entry and during early treatment with a return to opioid use. The trials compared MOUD treatment (buprenorphine, methadone, extended-release naltrexone) in populations with opioid use disorder (OUD). Non-opioid substances were identified through harmonizing self-reported use. The primary outcomes were markers of return to opioid use by 12 weeks.

RESULTS

When treatment cohorts were adjusted, no association between self-reported treatment entry use of non-opioid substances and week-12 opioid use was detected. During the first month of treatment, higher use of cocaine (OR 1.41 [1.18-1.69]) and amphetamine (OR 1.70 [1.27-2.26]) was found to be associated with higher likelihood of illicit opioid use by week 12. Exploratory analyses of potential treatment cohort-by-predictor interactions showed that those with heavier cocaine use had a lower rate of returning to opioid use in the extended-release naltrexone group than in the methadone group.

CONCLUSION

Substance use other than opioids at treatment entry is not associated with relapse. Use of cocaine or amphetamines during the first few weeks of MOUD treatment may signal a worse outcome, suggesting a need for additional interventions.