Changes in lipid profile and glucose metabolism following administration of bupropion alone or in combination with naltrexone: A systematic review and meta-regression analysis

BACKGROUND

Considering the conflicting effects of bupropion on parameters related to metabolic syndrome including glucose metabolism and lipid profile, in this meta-analysis study, we investigated the effects of this drug alone or in combination with naltrexone on glucose metabolism and lipid profile.

METHODS

Scopus, PubMed/Medline, Web of Science and Embase databases were searched using standard keywords to identify all controlled trials investigating effects of bupropion alone and combined with naltrexone on the glucose and lipid profile. Pooled weighted mean difference and 95% confidence intervals were achieved by random-effects model.

RESULTS

Twelve studies with 5152 participants' were included in this article. The pooled findings showed that bupropion alone or in combination with naltrexone would significantly reduce glucose (weighted mean difference (WMD): -2.25 mg/dL, 95% confidence interval (CI): -4.10, -0.40), insulin (WMD: -4.06 μU/mL, 95% CI: -6.09, -2.03), homeostatic model assessment for insulin resistance (HOMA-IR) (WMD: -0.58, 95% CI: -0.98, -0.19), triglyceride (TG) (WMD: -11.78 mg/dL, 95% CI: -14.48 to -9.08) and increase high-density lipoprotein (HDL) (WMD: 2.68 mg/dL, 95% CI: 2.13 to 3.24). A Greater reduction in glucose levels was observed with duration >26 weeks. Dose of bupropion intake ≤360 mg and intervention for more than 26 weeks decreased insulin level significantly. With regard to lipid profile, reduction of triglycerides is more significant with dose of bupropion greater than 360 mg and a shorter intervention length equal to 26 weeks.

CONCLUSIONS

The addition of combination therapies such as bupropion and naltrexone to lifestyle modification can significantly improve glucose metabolism and some lipid parameters.

Clinical Implications of the Relationship Between Naltrexone Plasma Levels and the Subjective Effects of Heroin in Humans

BACKGROUND

Extended-release naltrexone (NTX) is an opioid antagonist approved for relapse prevention after medical withdrawal. Its therapeutic effect is dependent on the NTX plasma level, and as it decreases, patients may lack protection against relapse and overdose. Therefore, identifying the minimally effective NTX level needed to block opioid-induced subjective effects has important clinical implications.

METHODS

This secondary, individual-level analysis of data collected in a human laboratory study was conducted to evaluate the relationship between NTX levels and subjective effects of an intravenously administered 25-mg challenge dose of heroin in non-treatment-seeking participants with opioid use disorder (N = 12). Subjective ratings of drug liking using a 100-mm visual analog scale (VAS) and NTX levels were measured across 6 weeks after participants received a single injection of either extended-release NTX 192 mg (N = 6) or 384 mg (N = 6). Cubic spline mixed-effects models were used to provide 95% prediction intervals for individual changes in liking scores as a function of NTX levels.

RESULTS

Naltrexone levels above 2 ng/mL blocked nearly all VAS ratings of drug liking after intravenous heroin administration. Participants with NTX levels ≥ 2 ng/mL had minimal (≤20 mm) changes from placebo in VAS ratings of drug liking based on 95% prediction intervals. In contrast, NTX levels < 2 ng/mL were associated with greater variability in individual-level subjective responses.

CONCLUSIONS

In clinical practice, a plasma level range of 1 to 2 ng/mL is considered to be therapeutic in providing heroin blockade. The current findings suggest that a higher level (>2 ng/mL) may be needed to produce a consistent blockade.

Preclinical Models of Attention Deficit Hyperactivity Disorder: Neurobiology, Drug Discovery, and Beyond

OBJECTIVE

We offer an overview of ADHD research using mouse models of nicotine exposure.

METHOD

Nicotine exposure of C57BL/6 or Swiss Webster mice occurred during prenatal period only or during the prenatal and the pre-weaning periods. Behavioral, neuroanatomical and neurotransmitter assays were used to investigate neurobiological mechanisms of ADHD and discover candidate ADHD medications.

RESULTS

Our studies show that norbinaltorphimine, a selective kappa opioid receptor antagonist is a candidate novel non-stimulant ADHD treatment and that a combination of methylphenidate and naltrexone has abuse deterrent potential with therapeutic benefits for ADHD. Other studies showed transgenerational transmission of ADHD-associated behavioral traits and demonstrated that interactions between untreated ADHD and repeated mild traumatic brain injury produced behavioral traits not associated with either condition alone.

CONCLUSION

Preclinical models contribute to novel insights into ADHD neurobiology and are valuable tools for drug discovery and translation to benefit humans with ADHD.

The effects of bupropion alone and combined with naltrexone on blood pressure and CRP concentration: A systematic review and meta-regression analysis of randomized controlled trials

BACKGROUND

Considering the conflicting effects of bupropion on parameters related to cardiovascular system including blood pressure and inflammation, in this meta-analysis study, we investigated the effects of this drug alone or in combination with naltrexone on systolic (SBP) and diastolic blood pressure (DBP) and C-reactive protein (CRP).

METHODS

Scopus, PubMed/Medline, Web of Science and Embase databases were searched using standard keywords to identify all controlled trials investigating effects of bupropion alone and combined with naltrexone on the BP and CRP. Pooled weighted mean difference and 95% confidence intervals (CIs) were achieved by random-effects model analysis for the best estimation of outcomes.

RESULTS

The pooled findings showed that that bupropion alone or in combination with naltrexone would significantly increase SBP (weighted mean difference (WMD): 1.34 mmHg, 95% CI: 0.38-2.29) and DBP (WMD: 0.93 mmHg, 95% CI 0.88-0.99) as well as decrease CRP (WMD: -0.89 mg/L, 95% CI -1.09 to -0.70). The findings of the subgroup also show the greater effect of bupropion on blood pressure (SBP and DBP) increase in a dose greater than 360 mg and a duration of intervention less equal to 26 weeks. In addition, the subgroup analysis showed that changes in SBP after receiving bupropion together with naltrexone were more compared to bupropion alone.

CONCLUSIONS

The addition of combination therapies such as bupropion and naltrexone can significantly improve CRP levels. However, its effect on blood pressure requires proper management of this drug.

Efficacy and Safety of Low Dose Naltrexone for Chronic Pain

Naltrexone is a mu-opioid receptor antagonist increasingly used as an analgesic for chronic pain at low doses. This retrospective, observational cohort study was conducted at an academic medical center to evaluate low-dose naltrexone (LDN) efficacy and describe its use in routine clinical practice. Adults receiving LDN, doses <10 mg for ≥1 month, seen at an outpatient pain clinic from January 1, 2014 to April 1, 2022 were included. The primary outcome was change in the Pain, Enjoyment of Life, and General Activity (PEG) score after LDN. Thirty-one patients were included. Median age was 50 years and 71% were female. Median duration of pain at baseline was 5 years. Mean PEG scores were 7.27 ± 1.39 and 6.62 ± 2.04 at baseline and follow-up, respectively. Mean difference was 0.66 (95% CI [0.10-1.21], p = 0.022). Eighty-seven percent (27) of patients discontinued LDN, 52% (16) for lack of benefit, 23% (7) for loss of benefit, 10% (3) for side effects, and 3% (1) for other reasons. Seven (23%) reported side effects. LDN was associated with a statistically significant reduction in PEG in adult chronic pain patients, however the clinical significance is unclear as over 75% of patients discontinued LDN due to lack of benefit.

Low-Dose Naltrexone for Excoriation Disorder

Excoriation (skin-picking) disorder (ED) is a condition characterized by the repeated compulsion to pick at the skin, causing physical trauma and psychiatric distress. Patients often desire to cease skin-picking behavior but are unable to do so. Multiple treatment modalities are effective for ED, including naltrexone. Previous reports of naltrexone for ED were at a high dose of 50 mg. The efficacy of low-dose naltrexone (LDN) at 4.5 mg in managing ED has not been reported. We present a case of a 51-year-old female with ED who was evaluated in the pain clinic for fibromyalgia management. Her medications included gabapentin 600 mg PO TID and a history of opioid prescription for diffuse pain. She was started on naltrexone 4.5 mg PO QD for the management of fibromyalgia. Three months later, the patient reported improvement in her skin-picking disorder, with a lessened compulsion to itch at her skin and improved healing of existing lesions. When the naltrexone was temporarily interrupted for an elective procedure, her lesions worsened. Her lesions improved after she resumed the medication. Thereby, this patient experienced a therapeutic benefit from naltrexone for her skin-picking disorder, as demonstrated by the temporal changes in her symptoms. To our knowledge, this is the first reported case of ED improving with LDN, as other cases utilized 50 mg. Though few clinical trials or systematic reviews recommend the use of naltrexone for EDs, our case supports trialing LDN in the appropriate context.

Pregnancy Rates Among Women Treated with Medication for Opioid Use Disorder

BACKGROUND

Treatment-seeking people with opioid use disorder (OUD) who are capable of pregnancy need accurate information about the potential impact of medication to treat OUD (MOUD) on fertility to make informed choices about treatment that are consistent with their reproductive wishes. There is a dearth of research on fertility associated with MOUD receipt in birthing people with OUD.

OBJECTIVE

To estimate the association between treatment with MOUD and odds of conception among birthing people using national administrative claims.

DESIGN

Retrospective case-crossover study using multi-state US administrative data (2006-2016). Dates of conception were estimated from delivery dates and served as "case" days for which MOUD exposures were compared to those on all other ("control") days of insurance enrollment.

PARTICIPANTS

Treatment-seeking people with OUD with a delivery during the observation period.

MAIN MEASURES

Odds ratios for conception from within-person fixed effects models were modeled as a function of exposure to MOUD (buprenorphine, methadone, extended-release depot naltrexone, or oral naltrexone) using conditional logistic regression.

KEY RESULTS

A total of 21,928 births among 19,133 people with OUD were identified. In the sample, 5873 people received buprenorphine, 1825 methadone, 486 extended-release naltrexone, and 714 oral naltrexone. Participants could receive more than one type of MOUD. Mean age was 28.2 years (SD = 2.2; range = 16-45), with 76.2% having Medicaid. vs. commercial insurance. Compared to no MOUD, periods of methadone (aOR = 0.55 [95% CI = 0.48-0.63]) or buprenorphine receipt (aOR = 0.84 [0.77-0.91]) were associated with fewer conceptions. Treatment periods with extended-release depot naltrexone compared to no medication were associated with higher odds of conception (aOR = 1.75 [1.22-2.50]) and there was no significant difference in conception with oral naltrexone (aOR = 1.02 [0.67-1.54]).

CONCLUSIONS

The association between MOUD and odds of conception among birthing people varied by type of MOUD, with extended-release naltrexone associated with higher odds of conceiving compared to no treatment. Clinical studies are urgently needed to investigate these findings further.

Multimodal Acute Pain Management in the Parturient with Opioid Use Disorder: A Review

The opioid epidemic in the United States has led to an increasing number of pregnant patients with opioid use disorder (OUD) presenting to obstetric units. Caring for this complex patient population requires an interdisciplinary approach involving obstetricians, anesthesiologists, addiction medicine physicians, psychiatrists, and social workers. The management of acute pain in the parturient with OUD can be challenging due to several factors, including respiratory depression, opioid tolerance, and opioid-induced hyperalgesia. Patients with a history of OUD can present in one of three categories: 1) those with untreated OUD; 2) those who are currently abstinent from opioids; 3) those being treated with medications to prevent withdrawal. A patient-centered, multimodal approach is essential for optimal peripartum pain relief and prevention of adverse maternal and neonatal outcomes. Medications for opioid use disorder (MOUD), previously referred to as medication-assisted therapy (MAT), include opioids like methadone, buprenorphine, and naltrexone. These are prescribed for pregnant patients with OUD, but appropriate dosing and administration of these medications are critical to avoid withdrawal in the mother. Non-opioid analgesics such as acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) can be used in a stepwise approach, and regional techniques like neuraxial anesthesia and truncal blocks offer opioid-sparing options. Other medications like ketamine, clonidine, dexmedetomidine, nitrous oxide, and gabapentinoids show promise for pain management but require further research. Overall, a comprehensive pain management strategy is essential to ensure the well-being of both the mother and the fetus in pregnant patients with OUD.

Implementation and analysis of a multifaceted intervention for alcohol use disorder from a single academic urban emergency department

BACKGROUND

From 2006 to 2014, alcohol-related visits to the emergency department (ED) increased by 76% in the United States, highlighting the need for improved ED-driven interventions addressing alcohol use disorder (AUD). Naltrexone is an FDA-approved medication for AUD shown to decrease craving and self-administration of alcohol. While oral naltrexone and extended-release naltrexone have been long utilized in primary care and inpatient hospital settings, the use of naltrexone in the ED is limited.

METHODS

This study implemented and analyzed a multifaceted intervention regarding ED naltrexone prescribing at a large safety net, academic, urban hospital. A baseline assessment of preintervention conditions and perspectives on naltrexone prescribing was conducted through a chart review and standardized interviews with ED providers, respectively. The interview results guided design of interventions that addressed identified barriers. These included provider education, prescribing aids, and zero-cost naltrexone tablets supplied by the ED pharmacy to patients upon discharge.

RESULTS

Between September 1, 2019, and August 31, 2020, of 753 unique patients who had a primary diagnosis or chief complaint containing the word "alcohol," only five (0.66%) were prescribed naltrexone. ED providers identified lack of training regarding naltrexone, lack of a prescribing protocol, and limited patient and provider education materials as barriers to prescribing naltrexone. Following the intervention, among 278 eligible patients, 11 oral naltrexone prescriptions were written (3.96%) between April 13, 2021, and August 1, 2021. This represents a sixfold increase over the preintervention period.

CONCLUSIONS

An intervention to increase ED oral naltrexone prescriptions for AUD was successfully implemented, addressing lack of provider education, lack of prescribing resources, and patient barriers to accessing prescribed medications. Longer-term follow-up is needed to assess the efficacy and sustainability of these interventions. Nevertheless, ED clinicians are well positioned to initiate naltrexone prescriptions for patients presenting with AUD.

Pharmacist-Driven Alcohol Use Disorder Screening May Increase Inpatient Utilization of Extended-Release Naltrexone: A Single Center Pilot Study

Individuals with mental illness have a high incidence of comorbid substance use, with one of the most prevalent being alcohol use disorder (AUD). Naltrexone, FDA-approved for AUD, decreases reward associated with alcohol-related social cues. This study aimed to determine if a pharmacist-driven screening tool would increase the use of extended-release naltrexone (XR-NTX) in patients with AUD and a comorbid psychiatric condition. Pharmacists screened and recommended XR-NTX for adults admitted to the inpatient psychiatric unit, who had a DSM-5 diagnosis of AUD, a negative urine drug screen for opioids, and were hospitalized for at least 1 day. Endpoints evaluated included the number of XR-NTX doses administered during the screening period to the prescreening period, 30-day readmission rates, recommendation acceptance rates, and reasons for not administering XR-NTX. Pharmacists identified 66 of 641 screened patients who met the inclusion criteria and were candidates for XR-NTX. Compared to the preintervention period, more patients received XR-NTX for AUD (2 vs. 8). Readmission rates were similar between those with AUD who received XR-NTX and those who did not. Pharmacist-driven screening for AUD led to greater administration of XR-NTX when compared to the same 4-month period the year prior to initiating the study.

Management of Critically Ill Patients Receiving Medications for Opioid Use Disorder

TOPIC IMPORTANCE

Critical care clinicians are likely to see an increasing number of patients admitted to the ICU who are receiving US Food and Drug Administration-approved medications for opioid use disorder (MOUDs) given the well-documented benefits of these agents. Oral methadone, multiple formulations of buprenorphine, and extended-release naltrexone are the three types of MOUD most likely to be encountered by ICU clinicians; however, these drugs vary with respect to formulations, pharmacokinetics, and adverse effects.

REVIEW FINDINGS

No published clinical practice guidelines or consensus statements are available to guide decision-making in patients admitted to the ICU setting who are receiving MOUDs before admission. Additionally, no randomized trials and limited observational studies have evaluated issues related to MOUD use in the ICU. Therefore, ICU clinicians caring for patients admitted who are taking MOUDs must base their decision-making on data extrapolation from pharmacokinetic, pharmacologic, and clinical studies performed in non-ICU settings.

SUMMARY

Despite the challenges in administering MOUDs in critically ill patients, extrapolation of data from other hospital settings suggests that the benefits of continuing MOUD therapy outweigh the risks in patients able to continue therapy. This article provides guidance for critical care clinicians caring for patients admitted to the ICU already receiving methadone, buprenorphine, or extended-release naltrexone. The guidance includes algorithms to aid clinicians in the clinical decision-making process, recognizing the inherent limitations of the existing evidence on which the algorithms are based and the need to account for patient-specific considerations.

The Medications for Opioid Use Disorder Study: Methods and Initial Outcomes From an 18-Month Study of Patients in Treatment for Opioid Use Disorder

OBJECTIVE

Opioid use disorder (OUD) affects approximately 5.6 million people in the United States annually, yet rates of the use of effective medication for OUD (MOUD) treatment are low. We conducted an observational cohort study from August 2017 through May 2021, the MOUD Study, to better understand treatment engagement and factors that may influence treatment experiences and outcomes. In this article, we describe the study design, data collected, and treatment outcomes.

METHODS

We recruited adult patients receiving OUD treatment at US outpatient facilities for the MOUD Study. We collected patient-level data at 5 time points (baseline to 18 months) via self-administered questionnaires and health record data. We collected facility-level data via questionnaires administered to facility directors at 2 time points. Across 16 states, 62 OUD treatment facilities participated, and 1974 patients enrolled in the study. We summarized descriptive data on the characteristics of patients and OUD treatment facilities and selected treatment outcomes.

RESULTS

Approximately half of the 62 facilities were private, nonprofit organizations; 62% focused primarily on substance use treatment; and 20% also offered mental health services. Most participants were receiving methadone (61%) or buprenorphine (32%) and were predominately non-Hispanic White (68%), aged 25-44 years (62%), and female (54%). Compared with patient-reported estimates at baseline, 18-month estimates suggested that rates of abstinence increased (55% to 77%), and rates of opioid-related overdoses (7% to 2%), emergency department visits (9% to 4%), and arrests (15% to 7%) decreased.

CONCLUSIONS

Our results demonstrated the benefits of treatment retention not only on abstinence from opioid use but also on other quality-of-life metrics, with data collected during an extended period. The MOUD Study produced rich, multilevel data that can lay the foundation for an evidence base to inform OUD treatment and support improvement of care and patient outcomes.

Weight loss medication prescription prevalence in the active component, 2018-2023

The U.S. military has witnessed rising obesity among active component service members. The Department of Defense authorized coverage of weight loss medications in 2018, but no study has evaluated prescription prevalence within the active component. This descriptive retrospective cohort study analyzed data from active component U.S. military service members from January 2018 through June 2023. The study used data from the Defense Medical Surveillance System to determine prescription period prevalence of weight loss medication. Data on demographics, body mass index, and history of diabetes were considered. The study revealed a 100-fold increase in the prescription period prevalence of weight loss agents in the active component from their initial authorization date. Demographics associated with higher prescription period prevalence were non-Hispanic Black race and ethnicity, female sex, and older age. Service members in the health care occupations and the Navy had higher prevalence compared to other service branches and occupations. The findings indicate a significant rise in the period prevalence of weight loss prescriptions over time. Further research is recommended to assess the effectiveness, safety, and use in austere military environments.

Patterns of publicly funded naltrexone use among patients diagnosed with alcohol use disorder in Ontario

AIMS

Naltrexone is recommended first-line to manage alcohol use disorder (AUD). With previous studies indicating poor retention on naltrexone, we determined duration of naltrexone use and assessed the association between prescription setting and time to discontinuation in Ontario.

METHODS

We conducted a retrospective population-based cohort study among Ontario public drug beneficiaries diagnosed with AUD who initiated publicly funded naltrexone from June 2018 to September 2019. The primary outcome was time to naltrexone discontinuation, with a secondary analysis assessing receipt of at least one prescription refill. We used Cox proportional hazards models and logistic regression to test the association between prescription setting and each medication persistence outcome.

RESULTS

Among 2531 new naltrexone patients with AUD, the median duration of naltrexone use was 31 days and 394 (15.6%) continued naltrexone for 6 months or longer. There was no association between setting of initiation and duration of naltrexone use; however, those initiating naltrexone following an acute inpatient hospital stay were more likely to fill a second prescription (aOR 1.43, 95% CI 0.96-2.14), while those initiating after an ED visit were less likely to be dispensed a second prescription (aOR = 0.69, 95% CI 0.52-0.90) compared to those starting in a physician's office.

CONCLUSION

Persistence on naltrexone to treat an AUD is low, regardless of the setting of initiation. Further research is needed to elucidate the barriers encountered by patients with AUD that lead to poor treatment persistence in order to develop interventions that facilitate patient-centered access to evidence-based treatment for AUD in the province.

Influence of sleep quality on lapse to alcohol use during a quit attempt

AIMS

Sleep problems are common among individuals with alcohol use disorder (AUD) and is often associated with a heightened relapse risk. The present study examines the relationship between sleep and alcohol use among individuals with current AUD during a 6-day quit attempt as part of a medication study.

METHODS

The current study is a secondary analysis of a medication trial for individuals with AUD. Individuals with AUD (N = 53, 26 females) were randomized to active medication or matched placebo. Randomized participants completed a week-long medication titration (Days 1-7). Following the titration period, participants attended an in-person visit (Day 8) to begin a 6-day quit attempt. During the quit attempt, participants completed daily diary assessments to report on previous day alcohol consumption, sleep quality, and alcohol craving. In the present study, medication condition was controlled for in all models.

RESULTS

Baseline global sleep quality was not a significant predictor of drinks per drinking day (P = 0.72) or percent days abstinent (P = 0.16) during the 6-day practice quit attempt. Daily diary analyses found that greater sleep quality was associated with higher next-day drinks per drinking day (b = 0.198, P = 0.029). In contrast, participants reported worse sleep quality following nights of greater alcohol intake, albeit at a trend-level (b = -0.12, P = 0.053).

CONCLUSIONS

These results suggest that better sleep quality was a risk factor for drinking during the 6-day quit period, such that better sleep may be associated with increased craving for alcohol and alcohol use the next day. These findings are limited to the early abstinence period and should be considered in studies exploring longer periods of abstinence.

Unraveling the neuroprotective mechanisms of naltrexone against aluminum-induced neurotoxicity

Aluminum (Al) is a known neurotoxic trace element linked to Alzheimer's disease (AD). Naltrexone, an opioid antagonist, has shown promising effects in reducing neuroinflammation at lower doses than those prescribed for addiction. This study aimed to determine the neuroprotective effects of naltrexone on Al-induced neurotoxicity in an in vitro AD model. The SH-SY5Y cells were first cultivated in a standard growth medium. Subsequently, the cells were induced to differentiate by decreasing the concentration of fetal bovine serum and introducing retinoic acid (RA) into the culture media. Subsequently, the inclusion of brain-derived neurotrophic factor (BDNF) was implemented in conjunction with RA. The process of differentiation was concluded on the seventh day. Study groups (n = 3) were designed as the control group, naltrexone group, Al group, Al-Nal group, Alzheimer' model (AD) group, Alzheimer model + Al-exposed group (AD-Al), Alzheimer model + Nal applied group (AD-Nal) and Alzheimer model + Al-exposed + Nal applied group (AD-Al-Nal). Hyperphosphorylated Tau protein as the specific marker of AD was measured in all groups. Glycogen synthase kinase-3 (GSK-3)β, Protein phosphatase 2A (PP2A), Akt and Wnt signaling pathways were analyzed comparatively. In addition, oxidative stress parameters (total antioxidant capacity, lipid peroxidase, protein carbonyl and reactive oxygen species) were measured comparatively in the study groups. The results showed that naltrexone reduced hyperphosphorylated tau protein levels by regulating GSK-3β, PP2A, Akt and Wnt signaling. Also, exposure to naltrexone decreased oxidative stress parameters. Based on these results, naltrexone shows promise as a potential therapy for AD, subject to additional clinical assessments.

Simultaneous Determination of Levo-tetrahydropalmatine and Naltrexone in Rat Plasma by LC-MS/MS and its Application in a Pharmacokinetic Study

BACKGROUND

Levo-tetrahydropalmatine and low-dose naltrexone are used in association with reducing cocaine-related cravings, but there are no analytical methods for the quantitative simultaneous analysis of this drug combination.

OBJECTIVE

A highly selective and sensitive LC-MS/MS assay was developed and validated to simultaneously quantify l-THP and naltrexone. The analytical method for l-THP offers improved sensitivity compared to previously published methods.

METHODS

The product ion transitions of l-THP and naltrexone were 357.0→193.0 and 342.2→324.1, respectively. Chromatographic separations were performed using a BEH-C18 column by an isocratic elution mode with acetonitrile and 0.1% formic acid in water containing 3 mM ammonium acetate. L-THP and naltrexone were extracted from rat plasma using a liquidliquid extraction method.

RESULTS

For l-THP and naltrexone, the assay displayed good linear response over a concentration range of 0.5-1000 ng/mL and 0.25-500 ng/mL, respectively. The intra-day accuracy of the method for l-THP and naltrexone was 93.8-101% with a precision (%CV) of 2.43-8.15% and 93.4-108% with a precision of 3.47-8.22%. The inter-day accuracy for l-THP and naltrexone was 91.2-102% with a CV of 2.46-8.06% and 91.5-97.8% with a CV of 3.29-8.92%, respectively.

CONCLUSION

The assay has been used for pharmacokinetic studies of l-THP and naltrexone in the rat.

Disulfiram for the treatment of cocaine dependence

BACKGROUND

Cocaine is a psychostimulant used by approximately 0.4% of the general population worldwide. Cocaine dependence is a chronic mental disorder characterised by the inability to control cocaine use and a host of severe medical and psychosocial complications. There is current no approved pharmacological treatment for cocaine dependence. Some researchers have proposed disulfiram, a medication approved to treat alcohol use disorder. This is an update of a Cochrane review first published in 2010.

OBJECTIVES

To evaluate the efficacy and safety of disulfiram for the treatment of cocaine dependence.

SEARCH METHODS

We updated our searches of the following databases to August 2022: the Cochrane Drugs and Alcohol Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and PsycINFO. We also searched for ongoing and unpublished studies via two trials registries. We handsearched the references of topic-related systematic reviews and included studies. The searches had no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials that evaluated disulfiram alone or associated with psychosocial interventions versus placebo, no intervention, other pharmacological interventions, or any psychosocial intervention for the treatment of cocaine dependence.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

Thirteen studies (1191 participants) met our inclusion criteria. Disulfiram versus placebo or no treatment Disulfiram compared to placebo may increase the number of people who are abstinent at the end of treatment (point abstinence; risk ratio (RR) 1.58, 95% confidence interval (CI) 1.05 to 2.36; 3 datasets, 142 participants; low-certainty evidence). However, compared to placebo or no pharmacological treatment, disulfiram may have little or no effect on frequency of cocaine use (standardised mean difference (SMD) -0.11 standard deviations (SDs), 95% CI -0.39 to 0.17; 13 datasets, 818 participants), amount of cocaine use (SMD -0.00 SDs, 95% CI -0.30 to 0.30; 7 datasets, 376 participants), continuous abstinence (RR 1.23, 95% CI 0.80 to 1.91; 6 datasets, 386 participants), and dropout for any reason (RR 1.20, 95% CI 0.92 to 1.55; 14 datasets, 841 participants). The certainty of the evidence was low for all these outcomes. We are unsure about the effects of disulfiram versus placebo on dropout due to adverse events (RR 12.97, 95% CI 0.77 to 218.37; 1 study, 67 participants) and on the occurrence of adverse events (RR 3.00, 95% CI 0.35 to 25.98), because the certainty of the evidence was very low for these outcomes. Disulfiram versus naltrexone Disulfiram compared with naltrexone may reduce the frequency of cocaine use (mean difference (MD) -1.90 days, 95% CI -3.37 to -0.43; 2 datasets, 123 participants; low-certainty evidence) and may have little or no effect on amount of cocaine use (SMD 0.12 SDs, 95% CI -0.27 to 0.51, 2 datasets, 123 participants; low-certainty evidence). We are unsure about the effect of disulfiram versus naltrexone on dropout for any reason (RR 0.86, 95% CI 0.56 to 1.32, 3 datasets, 131 participants) and dropout due to adverse events (RR 0.50, 95% CI 0.07 to 3.55; 1 dataset, 8 participants), because the certainty of the evidence was very low for these outcomes.

AUTHORS' CONCLUSIONS

Our results show that disulfiram compared to placebo may increase point abstinence. However, disulfiram compared to placebo or no pharmacological treatment may have little or no effect on frequency of cocaine use, amount of cocaine use, continued abstinence, and dropout for any reason. We are unsure if disulfiram has any adverse effects in this population. Caution is required when transferring our results to clinical practice.

The impact of cannabis on non-medical opioid use among individuals receiving pharmacotherapies for opioid use disorder: a systematic review and meta-analysis of longitudinal studies

Background: The relationship between cannabis use and the risk of returning to using opioids non-medically during treatment for opioid use disorder (OUD) remains unclear.Objective: We sought to quantify the impact of cannabis use on the risk of non-medical opioid use among people receiving pharmacotherapies for OUD.Methods: A comprehensive search was performed using multiple databases from March 1 to April 5 of 2023. Eligible studies longitudinally assessed the association between cannabis use and non-medical opioid use among people with OUD receiving treatment with buprenorphine, methadone, or naltrexone. We utilized a random-effects model employing the restricted maximum likelihood method. A sensitivity analysis was conducted to understand potential differences between each OUD treatment modality.Results: A total of 10 studies were included in the final meta-analysis. There were 8,367 participants (38% female). The average follow-up time across these studies was 9.7 months (SD = 3.77), ranging from 4 to 15 months. The pharmacotherapies involved were methadone (76.3%) buprenorphine (21.3%), and naltrexone (2.4%). The pooled odds ratio did not indicate that cannabis use significantly influenced non-medical opioid use (OR: 1.00, 95% CI: 0.97-1.04, p = .98). There is evidence of moderate heterogeneity and publication bias.Conclusion: There was no significant association between cannabis use and non-medical opioid use among patients receiving pharmacotherapies for OUD. These findings neither confirm concerns about cannabis increasing non-medical opioid use during MOUD, nor do they endorse its efficacy in decreasing non-medical opioid use with MOUD. This indicates a need for individualized approaches for cannabis use and challenges the requirement of cannabis abstinence to maintain OUD pharmacotherapies.

Effects of naltrexone on amphetamine choice in rhesus monkeys and rats

Clinical amphetamine use is constrained by high abuse potential, and amphetamine use disorder is a persistent clinical problem with no approved medications for its treatment. The opioid antagonist naltrexone has been reported to reduce some abuse-related effects of amphetamine. This study used an amphetamine-versus-food choice procedure in rhesus monkeys and rats to test the hypothesis that naltrexone might serve as either (a) a maintenance medication for amphetamine use disorder treatment or (b) an "abuse-deterrent" adjunct to clinical amphetamine formulations. Male rhesus monkeys and male and female rats were trained to choose between increasing unit doses of intravenous amphetamine and an alternative food reinforcer during daily behavioral sessions. Experiment 1 evaluated effectiveness of continuous naltrexone maintenance to reduce amphetamine-versus-food choice in both monkeys and rats. Experiment 2 combined naltrexone with amphetamine in fixed-proportion amphetamine + naltrexone mixtures to evaluate the effectiveness of naltrexone in both species to reduce mixture choice relative to amphetamine-alone choice. Amphetamine maintained a dose-dependent increase in amphetamine choice in both monkeys and rats. Naltrexone maintenance did not significantly decrease amphetamine choice in either species. Addition of naltrexone to amphetamine reduced amphetamine choices per session in monkeys, but behavior was not reallocated to food choice, and in rats, the addition of naltrexone only decreased food choice without significantly affecting amphetamine choice. These results argue against the use of naltrexone as either (a) a maintenance medication for treatment of amphetamine use disorder or (b) an "abuse-deterrent" adjunct to amphetamine for clinical applications. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Prior authorization restrictions on medications for opioid use disorder: trends in state laws from 2005 to 2019

RESEARCH OBJECTIVE

Medications for opioid use disorder (MOUDs) - including methadone, buprenorphine, and naltrexone - are the most effective treatments for opioid use disorder (OUD). Historically, insurers have required prior authorization for MOUD, but prior authorization is often reported as a key barrier to MOUD prescribing. Some states have passed laws prohibiting MOUD prior authorization requirements. We sought to identify the frequency of MOUD prior authorization prohibitions in state laws and to categorize types of prohibitions.

METHODS

We searched for regulations and statutes present in all U.S. states and Washington DC between 2005 and 2019 using MOUD-related terms in Westlaw legal software. In qualitative software, we coded laws discussing MOUD prior authorization using template analysis - a mixed deductive/inductive approach. Finally, we used coded laws to identify frequencies of states with prior authorization prohibitions, including changes over time.

RESULTS

No states had laws prohibiting MOUD prior authorization between 2005 and 2015, with the first prohibition appearing in 2016. By 2019, fifteen states had MOUD prior authorization prohibitions. States varied significantly in their approach to prohibiting MOUD prior authorization. In 2019, it was more common for states to have MOUD prior authorization prohibitions applying to all insurers (n = 10 states) than to only Medicaid (n = 7 states) or only non-Medicaid insurers (n = 1 state). In 2019, general prior authorization prohibitions (n = 10 states) were more common than prohibitions only applicable to medications on the formulary, prohibitions only applicable to medications on the preferred drug list, prohibitions only applicable during the first 5 days of treatment, and prohibitions only applicable during the first 30 days of treatment.

CONCLUSIONS

The number of states with an MOUD prior authorization law prohibition increased in recent years. Such laws could help expand access to life-saving OUD treatments by making it easier for clinicians to prescribe MOUD.KEY MESSAGESNo states had MOUD prior authorization prohibitions between 2005 and 2015 in state statutes or regulations, and only one state had such a prohibition in 2016.By 2019, fifteen states had an MOUD prior authorization prohibition law.States varied significantly in their approach to prohibiting MOUD prior authorization, including with respect to the insurer type, duration of the prohibition, and applicable medication.

Fentanyl-induced respiratory depression in rodents is inhibited by bioabsorbable, subcutaneous naltrexone implants at 3.5 months

The aim of this study is to determine if extended-release, bioabsorbable, subcutaneous naltrexone (NTX) implants inhibit respiratory depression after an IV injection of fentanyl. Bioabsorbable implants fabricated from two different release-controlling polymers, poly-D-L-lactide (PDLLA) and polycaprolactone (PCL), alone (placebo) or containing NTX, were subcutaneously implanted in Sprague Dawley rats. After 3.5 months of implantation, the rodents were administered an IV bolus of fentanyl through the tail vein. The placebo implant rats received a dose of 4 micrograms (mcg) - (10 mcg/kg/dose), while the NTX implanted animals received a dose of 8 mcg (20 mcg/kg/dose). The minimum active dose of fentanyl that caused a > 50 ± 2% depression in the respiration rate in the placebo implanted rodents was 4 mcg. The respiration rate of the placebo implanted rats dropped from 208 ± 14 breaths/minute at predose, to 84 ± 12 breaths/minute (p = 0.0003) at 2 min. In contrast, all NTX implanted animals easily tolerated twice the dose of 8 mcg of fentanyl without any significant reduction in respiration rate. The mean respiration rate = increased from 164 ± 22 breaths/minute at predose to 178 ± 17 breaths/minute (p = 0.24) at 2 min. The mean plasma concentrations of NTX, 3.5 months after implantation, ranged from 7.4 (±1.1) ng/mL to 80.3 (±37.5) ng/mL. Bioabsorbable implants containing NTX effectively blocked fentanyl-induced respiratory depression in rodents as compared with placebo implants, 3.5 months after implantation.

A Case of Chronic Eosinophilic Pneumonia Associated With the Use of Weight Loss Combination Medication Naltrexone-Bupropion

Chronic eosinophilic pneumonia (CEP) is not a commonly encountered pulmonary disease that presents with bilateral pulmonary infiltrates accompanied by peripheral and bronchoalveolar lavage (BAL) eosinophilia. Recovery is rapid with systemic steroids but has frequent recurrences. We present a case with the classic presentation of CEP that appears to be related to a weight loss medication called naltrexone-bupropion. This case is unique in that this drug combination does not appear to have an established link to CEP, though literature reveals possible association with its individual components. Understanding the mechanism underlying this link may help to better understand CEP as a disease process.

Extinction and reinstatement of methamphetamine-induced conditioned place preference in zebrafish

Conditioned place preference (CPP) paradigm in zebrafish has been used to measure drug reward, but there is limited research on CPP reinstatement to determine relapse vulnerability. The present study aimed to investigate extinction and reinstatement of methamphetamine (MA)-induced CPP in zebrafish and evaluate the model's predictive validity. Zebrafish received different doses of MA (0-60 mg/kg) during CPP training. The preferred dose of MA at 40 mg/kg was used for extinction via either confined or nonconfined procedures. The extinguished CPP was reinstated by administering a priming dose of MA (20 mg/kg) or various stressors. To assess persistent susceptibility to reinstatement, MA CPP and reinstatement were retested following 14 days of abstinence. In addition, the effects of SCH23390, naltrexone, and clonidine on MA CPP during acquisition, expression, or reinstatement phases were monitored. MA induced CPP in a dose-dependent manner. Both nonconfined and confined extinction procedures time-dependently reduced the time spent on the MA-paired side. A priming dose of MA, chasing stress, or yohimbine reinstated the extinguished CPP. After 14 days of abstinence, the MA CPP remained extinguished and was significantly reinstated by MA priming or chasing stress. Similar to the observations in rodents, SCH23390 suppressed the acquisition of MA CPP, naltrexone reduced the expression and MA priming-induced reinstatement, while clonidine prevented stress-induced reinstatement of MA CPP. This work expanded the zebrafish CPP paradigm to include extinction and reinstatement phases, demonstrating predictive validity and highlighting its potential as a valuable tool for exploring drug relapse.

National Provider Survey: Use of Naltrexone for Pregnant Individuals with Substance Use Disorders

OBJECTIVES

A national survey evaluated the availability of naltrexone as a treatment for alcohol use disorder and/or opioid use disorder for pregnant individuals. Provider perceptions of barriers to treatment with naltrexone during pregnancy were also examined.

METHODS

Sites were selected from a national registry of naltrexone prescribers (N = 5208). A 10% sampling of sites within 150 miles of each state's capital was selected (n = 2073). Survey of 11 questions included availability of naltrexone for pregnant individuals, standard practices for treating pregnant individuals already on naltrexone, and barriers to treatment. Survey responses were summarized to identify top barriers and national trends in service availability.

RESULTS

Of the 236 sites contacted, 78 (33.1%) completed the survey. There was significant geographic variation in number of available sites, with Northeast United States having the most sites. Of the 78 responding sites, only 23 (35.9%) offered naltrexone for pregnant individuals. The most common barriers to prescribing naltrexone included the following: sites without pregnant patients (15.6%), lack of national guidelines in using naltrexone for pregnant patients (14.1%), providers' discomfort with prescribing naltrexone during pregnancy due to safety concerns (9.4%), and providers' discomfort due to inexperience (4.7%).

CONCLUSIONS

Accessibility of naltrexone and related care for pregnant individuals with alcohol use disorder and opioid use disorder varies greatly across the United States with numerous barriers and educational gaps identified. Additional research and resources are needed to expand naltrexone treatment access for pregnant individuals.

The Impact of Post-Processing Temperature on PLGA Microparticle Properties

PURPOSE

Biodegradable poly(lactide-co-glycolide) (PLGA) microparticles loaded with either risperidone or naltrexone were prepared from an emulsification homogenization process. The objective of this study was to determine the impact the post-treatment temperature has on the properties and subsequent performance of the microparticles.

METHODS

The post-treatment temperature of an ethanolic solution was characterized from 10 ~ 35ºC for the naltrexone and risperidone micropartilces.

RESULTS

The wash temperature resulted in a typical triphasic in vitro release pattern at low wash temperatures or a biphasic pattern consisting of an elevated release rate at higher post-treatment temperatures. The post-treatment temperature largely influences the particle morphology, residual solvent levels, glass transition temperature, and drug loading and is molecule dependent, whereby these characteristics subsequently influence the drug release rate.

CONCLUSION

The study highlights the importance of both the post-treatment process and control during manufacturing to obtain a formulation within the desired product profile.

Using a cascade of care framework to identify gaps in access to medications for alcohol use disorder in British Columbia, Canada

BACKGROUND AND AIMS

Despite the significant burden of alcohol use disorder (AUD) and availability of safe and effective medications for AUD (MAUD), population-level estimates of access and engagement in AUD-related care are limited. The aims of this study were to generate a cascade of care for AUD in British Columbia (BC), Canada, and to estimate the impacts of MAUD on health outcomes.

DESIGN

This was a retrospective population-based cohort study using linked administrative health data.

SETTING

British Columbia, Canada, 2015-2019.

PARTICIPANTS

Using a 20% random sample of BC residents, we identified 7231 people with moderate-to-severe alcohol use disorder (PWAUD; overall prevalence = 0.7%).

MEASUREMENTS

We developed a six-stage AUD cascade (from diagnosis to ≥6 months retention in MAUD) among PWAUD. We evaluated trends over time and estimated the impacts of access to MAUD on AUD-related hospitalizations, emergency department visits and death.

FINDINGS

Between 2015 and 2019, linkage to AUD-related care decreased (from 80.4% to 46.5%). However, rates of MAUD initiation (11.4% to 24.1%) and retention for ≥1 (7.0% to 18.2%), ≥3 (1.2% to 4.3%) or ≥6 months (0.2% to 1.6%) increased significantly. In adjusted analyses, access to MAUD was associated with reduced odds of experiencing any AUD-related adverse outcomes, with longer retention in MAUD showing a trend to greater odds reduction: adjusted odds ratio (95% CI) ranging from 0.59 (0.48-0.71) for MAUD retention <1 month to 0.37 (0.21-0.67) for ≥6 months retention.

CONCLUSIONS

Access to medications for alcohol use disorder among people with moderate-to-severe alcohol use disorder in British Colombia, Canada increased between 2015 and 2019; however, initiation and retention remained low. There was a trend between longer retention in medications for alcohol use disorder and greater reductions in the odds of experiencing alcohol use disorder-related adverse outcomes.

Evaluation of the Use of Naltrexone for Cholestatic Pruritus

OBJECTIVE

Pruritus is a common symptom of liver disease, managed with various medications including opioid antagonists like naltrexone. Current literature surrounding the safety and efficacy of naltrexone for cholestatic pruritus is limited. Our objective was to describe naltrexone prescribing practices for cholestatic pruritus.

METHODS

We conducted a single-center, retrospective review of inpatients who received naltrexone for cholestatic pruritus. We gathered information on naltrexone dosing, frequency, dose adjustments, duration, elevations in liver function tests (LFTs), and use of additional antipruritic agents.

RESULTS

Thirty-nine patients and 122 dosing regimens were included for analysis. Most patients were male (56.4%) with a median age of 6.32 years (range, 0.63-18.89). The median weight-based doses of naltrexone were 1.45 mg/kg/dose (IQR, 0.84-2.81) and 1.86 mg/kg/day (IQR, 0.97-3.37). The median flat doses were 25 mg/dose (IQR, 12.25-50) and 50 mg/day (IQR, 25-50). The median number of additional antipruritic agents used before and after naltrexone initiation was 3 (IQR, 2-4) and 4 (IQR, 3-5), respectively (p < 0.001). The most common elevated LFTs were total bilirubin and alanine aminotransferase (ALT), occurring in 15% of patients.

CONCLUSIONS

Naltrexone dosing ranged between 1 and 2 mg/kg/dose once or twice daily, with larger weight-based doses prescribed in younger and lower-weight patients. Naltrexone was commonly added as a fourth-line agent and did not lead to discontinuation of other antipruritic therapies. Larger, prospective, controlled studies are needed to assess the safety and efficacy of naltrexone for cholestatic pruritus.

Treatment of dissociative symptoms with opioid antagonists: a systematic review

BACKGROUND

The clinical guidelines for the treatment of dissociation focus primarily on psychotherapy. However, different psychoactive drugs are used in clinical practice. The use of opioid antagonists has been proposed as a therapeutic option based on the theory that dissociation might be a phenomenon mediated by dysregulation of the endogenous opioid system.

OBJECTIVE

To review and meta-analyse the available evidence on the efficacy of the opioid antagonists naltrexone, naloxone, and nalmefene as treatments for dissociative symptoms and disorders.

METHOD

The PRISMA guidelines were followed, and this review was registered in Prospero with reference number CRD42021280976. The search was performed in the PubMed, Scopus, Web of Science, EMBASE, PsycINFO, and PubPsych databases.

RESULTS

1,798 citations were obtained. After removing duplicates and applying inclusion and exclusion criteria, we included 5 comparative studies with 9 dissociation measures that had included a total of 154 participants, of whom 134 had been treated with an opioid antagonist. The results of the meta-analysis showed a treatment effect for dissociation when using opioid antagonists [pooled d = 1.46 (95% CI: 0.62-2.31)]. However, the studies we included were very heterogeneous [Q = 66.89 (p < .001)] and there may have been publication bias.

CONCLUSIONS

Although more research is needed and the results must be interpreted with caution because of the limited amount of data and heterogeneity in the studies and their methodological qualities, opioid antagonists (particularly naltrexone) are promising candidates for the treatment of dissociative symptoms and showed a moderate - large effect size in reducing these symptoms.

Does treating pain with alcohol affect drinking reduction among women with HIV enrolled in a clinical trial of naltrexone?

BACKGROUND

Many women living with HIV (WLWH) experience pain. Alcohol use with the intent to treat pain could lead to hazardous drinking and difficulty in reducing drinking. Naltrexone acts on opioid receptors important for pain regulation and is an approved treatment for alcohol use disorder. In this secondary analysis of a randomized double-blind placebo-controlled naltrexone clinical trial, the goals were to (1) compare alcohol reduction between women who drank to treat pain and those who did not and (2) examine differences in alcohol reduction by both drinking intention and treatment arm.

METHODS

Women living with HIV (N = 194, mean age 48.3 years, 83% non-Hispanic Black, 11% Hispanic) with hazardous drinking (>7 drinks/week) were randomized to receive daily treatment with naltrexone 50 mg or placebo for 4 months. Study visits occurred at baseline and 2, 4, and 7 months (posttreatment). The number of drinks/week was measured using the Timeline Follow Back. Use of alcohol to treat pain was self-reported. Participants were categorized as using alcohol to treat pain or not and in the naltrexone or placebo group. Chi-square, t-test, MANOVA, and sequential mixed effects models were used to determine group differences in demographic factors, mean/drinks per week, and percent change in mean drinks/week at baseline and each follow-up visit.

RESULTS

There was a consistent decrease in drinking throughout the study. There was not a significant difference in mean drinks/week at any point in the study between women who used alcohol to treat pain and those who did not. When considering treatment arm, at 2 months only those who did not use alcohol to treat pain in the naltrexone group had a significantly lower mean drinks/week than the other groups (p = 0.007); all groups had similar decreases in drinking from 4 months onward.

CONCLUSION

In the naltrexone group, WLWH who drank to treat pain reduced their alcohol consumption more slowly than WLWH who did not drink to treat pain. Replication of these findings would suggest that alcohol treatment guidelines should address pain as a factor in drinking outcomes.

Anti-craving medications for alcohol use disorder treatment in the emergency department: A systematic review of direct evidence for SAEM GRACE

OBJECTIVES

Alcohol-related concerns commonly present to the emergency department (ED), with a subset of individuals experiencing the symptoms of an alcohol use disorder (AUD). As such, examining the efficacy of pharmacological anti-craving treatment for AUD in the ED is of increasing interest. The objective of this systematic review was to evaluate the direct evidence assessing the efficacy of providing anti-craving medications for AUD treatment in the ED.

METHODS

A systematic search was conducted according to the patient-intervention-control-outcome question: (P) adults (≥18 years old) presenting to the ED with an AUD (including suspected AUD); (I) anti-craving medications (i.e., naltrexone, acamprosate, gabapentin); (C) no prescription or placebo; (O) reduction of repeat ED visits, engagement in addiction services, reductions in heavy drinking days, reductions in any drinking and amount consumed (or abstinence), and in relapse. Two reviewers independently assessed articles for inclusion and conducted risk of bias assessments for included studies.

RESULTS

From 143 potentially relevant articles, 6 met inclusion criteria: 3 clinical trials, and 3 case studies. The clinical trials identified evaluated oral versus extended-release naltrexone, monthly extended-release naltrexone injections, and disulfiram. Both oral and extended-release naltrexone resulted in decreased alcohol consumption. Monthly extended-release naltrexone injections resulted in significant improvements in drinking and quality of life. Although out of scope, the disulfiram studies identified did not result in an improvement in drinking in comparison to no medication.

CONCLUSIONS

Overall, there are few studies directly examining the efficacy of anti-craving medications for AUD in the ED, although the limited evidence that exists is supportive of naltrexone pharmacotherapy, particularly extended-release injection formulation. Additional randomized controlled trials are necessary for substantive direct evidence on anti-craving medication initiation in the ED.

Comparison table: Some drugs for maintenance treatment of opioid use disorder

Some Drugs for Maintenance Treatment of Opioid Use Disorder

Open label trial of lofexidine-assisted non-opioid induction onto naltrexone extended-release injection for opioid use disorder

Background: Opioid use disorder (OUD) continues to be major public health problem in the US and innovative medication strategies are needed. The extended-release injectable formulation of naltrexone (ER-NTX), an opioid receptor antagonist, is an effective treatment for OUD, but the need for an opioid-free period during the induction phase of treatment is a barrier to treatment success, particularly in the outpatient setting. Lofexidine, an alpha-2-adrenergic agonist, is an effective treatment for opioid withdrawal.Objectives: To evaluate the feasibility, safety, and tolerability of lofexidine for facilitating induction onto ER-NTX in the management of OUD.Methods: In an open-label, uncontrolled, 10-week outpatient clinical trial, 20 adults (four women) with OUD were treated with a fixed-flexible dosing strategy (maximum 0.54 mg 4×/daily) of lofexidine for up to 10 days to manage opioid withdrawal prior to receiving ER-NTX. The COVID-19 pandemic resulted in a modification of the study methods after enrolling 10 participants who attended all visits in person. The second group of 10 participants attended most induction period visits remotely.Results: Overall, 10 of the 20 participants (50%) achieved the primary outcome by receiving the first ER-NTX injection. Rates of induction success did not differ by the presence of fentanyl or remote visit attendance, although the small sample size provided limited statistical power. Six out of 20 participants (30%) initiated on lofexidine required dose adjustments. There were no study-related serious adverse events.Conclusions: This study provides preliminary evidence supporting the feasibility of inducting individuals with OUD onto ER-NTX using lofexidine.

Safety study of topical naltrexone therapy for diabetic skin wounds is confirmed in Göttingen mini-pigs

This study was conducted to determine the safety of topical naltrexone treatment in Göttingen swine. Efficacy of topical naltrexone was performed previously in Sprague-Dawley rats. In this study, 25 male and female mini-pigs received topical naltrexone once daily for 30 days. The gel at doses of 1%, 2%, and 10% naltrexone was applied at a dose volume of 0.01 ml/cm2 to an area of unbroken skin encompassing 10% of the animal's surface. Body and food consumption, skin and organ morphology, and clinical signs, including blood analyses were taken periodically. Naltrexone levels in serum were measured at the time of death. No adverse observations were made in the cutaneous skin, autopsied organs, or biochemical parameters. The no-observed adverse effect level (NOAEL) was considered to be 2% topical application daily. The conclusions from the veterinarians and researchers are that topical naltrexone at 1% or 2% can be used safely in clinical efficacy studies.

Management of Concurrent Bipolar I Disorder and Compulsive Sexual Behavior Disorder: A Case Report

Pornography addiction is not currently recognized in the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-V), but it can be broadly classified under compulsive sexual behavior disorder (CSBD) in the International Classification for Diseases (ICD). An increased incidence of CSBD has been reported in patients with bipolar I disorder (BPI) as an independent compulsion, not secondary to mania. Due to the ambiguity of identifying pornography addiction in the DSM-V, approved treatment for patients with a concurrent diagnosis of CSBD in the context of BPI is limited. We report the case of a patient with CSBD with concurrent BPI and investigate the treatment strategy taken in an inpatient setting. Though there are no FDA-approved treatment strategies currently approved for patients with concurrent CSBD and BPI, selective serotonin reuptake inhibitors, mood stabilizers, naltrexone, and cognitive behavioral therapy can be used in combination for maximal benefit.

Circulating levels of proglucagon-derived peptides are differentially regulated by the glucagon-like peptide-1 agonist liraglutide and the centrally acting naltrexone/bupropion and can predict future weight loss and metabolic improvements: A 6-month long interventional study

AIM

To investigate the changes of circulating levels of all proglucagon-derived peptides (PGDPs) in individuals with overweight or obesity receiving liraglutide (3 mg) or naltrexone/bupropion (32/360 mg), and to explore the association between induced changes in postprandial PGDP levels and body composition, as well as metabolic variables, after 3 and 6 months on treatment.

MATERIALS AND METHODS

Seventeen patients with obesity or with overweight and co-morbidities, but without diabetes, were assigned to receive once-daily oral naltrexone/bupropion 32/360 mg (n = 8) or once-daily subcutaneous liraglutide 3 mg (n = 9). Participants were assessed before treatment initiation and after 3 and 6 months on treatment. At the baseline and 3-month visits, participants underwent a 3-hour mixed meal tolerance test to measure fasting and postprandial levels of PGDPs, C-peptide, hunger and satiety. Clinical and biochemical indices of metabolic function, magnetic resonance-assessed liver steatosis and ultrasound-assessed liver stiffness were measured at each visit.

RESULTS

Both medications improved body weight and composition, carbohydrate and lipid metabolism, and liver fat and function. Naltrexone/bupropion produced a weight-independent increase in the levels of proglucagon (P < .001) and decreases in glucagon-like peptide-2 (GLP-2), glucagon and the major proglucagon fragment (P ≤ .01), whereas liraglutide markedly upregulated total glucagon-like peptide-1 (GLP-1) levels in a weight-independent manner (P = .04), and similarly downregulated the major proglucagon fragment, GLP-2 and glucagon (P < .01). PGDP levels at the 3-month visit were positively and independently correlated with improvements in fat mass, glycaemia, lipaemia and liver function, and negatively with reductions in fat-free mass, at both the 3- and 6-month visits.

CONCLUSIONS

PGDP levels in response to liraglutide and naltrexone/bupropion are associated with improvements in metabolism. Our study provides support for the administration of the downregulated members of the PGDP family as replacement therapy (e.g. glucagon), in addition to the medications currently in use that induced their downregulation (e.g. GLP-1), and future studies should explore whether the addition of other PGDPs (e.g. GLP-2) could offer additional benefits.

Comorbid alcohol use disorder and posttraumatic stress disorder: A proof-of-concept randomized placebo-controlled trial of buprenorphine and naltrexone combination treatment

BACKGROUND

Effective pharmacologic treatments for comorbid alcohol use disorder (AUD) and posttraumatic stress disorder (PTSD) are lacking. Kappa (κ) opioid receptor antagonists may address this unmet need. Buprenorphine is a κ-opioid antagonist and a partial agonist of mu (μ) opioid receptors. Whereas naltrexone blocks all μ-mediated effects combining it with buprenorphine yields a pharmacologic net effect of opioid receptor antagonism. Because no κ-opioid receptor antagonist it available for clinical use, we tested this combination in a proof-of-concept study.

METHODS

Consenting participants were enrolled in a Phase II, multisite, double-blind, randomized, placebo-controlled trial evaluating the effectiveness of sublingual (SL) buprenorphine combined with extended-release (XR) injectable naltrexone for the treatment of comorbid AUD and PTSD. Eligible participants (n = 75) were randomized (1:1:1) to receive either buprenorphine 2 mg/day plus naltrexone-XR (n = 35), buprenorphine 8 mg/day plus naltrexone-XR (n = 6) or SL plus injectable placebo (n = 34) for 12 weeks. The buprenorphine 8 mg/day plus naltrexone-XR arm was dropped early in the trial due to the negative impact of COVID-19 on enrollment. A binary primary outcome of response at week 8 was defined as a decrease from baseline of ≥10 points on the past week Clinician-Administered PTSD Scale (CAPS-5) and a reduction of ≥1 of past month alcohol risk level, as defined by the World Health Organization (WHO) and measured by the Timeline Follow-Back.

RESULTS

Based on the results of a futility analysis, enrollment was stopped prior to reaching the initial goal of 90 participants. At the week eight primary timepoint, there were no statistically significant differences between buprenorphine plus naltrexone-XR and placebo group for the primary composite outcome (OR = 0.63; p-value = 0.52), or the subcomponents of the PTSD outcome (OR = 0.76; p-value = 0.69) and AUD outcome (OR = 0.17; p-value = 0.08). The placebo arm had a significantly higher proportion of participants with ≥1 WHO risk level reduction than the buprenorphine plus naltrexone-XR arm (OR = 0.18, p value = 0.02).

CONCLUSIONS

This is the first study to evaluate the potential of κ-opioid receptor antagonism for the treatment of comorbid AUD and PTSD. The combination of buprenorphine and naltrexone-XR showed no significant improvement over placebo for the composite, PTSD, or alcohol measures.

Association of Medication-Assisted Therapy and Risk of Drug Overdose-Related Hospitalization or Emergency Room Visits in Patients With Opioid Use Disorder

Objective To examine the differential impacts of medication-assisted therapy (MAT) medications (naltrexone, methadone, and buprenorphine) on drug overdose-related hospitalizations or emergency room (ER) visits in patients with opioid use disorder (OUD). Patients and methods A retrospective cohort study was performed on patients 18 years or older diagnosed with OUD, using Optum's de-identified Clinformatics® Data Mart database. To ensure a new diagnosis of OUD from 2018 to 2019, each patient required one year of continuous enrollment before OUD diagnosis. The primary outcome was the incidence of drug overdose-related hospitalization or ER visits in the follow-up period. Patients were censored at loss of coverage or end of the study (9/30/2020). A multivariable Cox proportional hazard model was built to compare the outcomes across three MAT medications (buprenorphine, methadone, and naltrexone). Results Only 10.38% of the 145,317 OUD patients received MAT prescriptions in the 12 months after diagnosis. The majority of MAT users (77.8%) received buprenorphine. At one year of follow-up, the incidence of drug overdose-related hospitalization or ER visits varied by MAT drug type: naltrexone (14.26%), methadone (12.26%), and buprenorphine (10.23%). Compared to methadone drug users, buprenorphine users had a lower risk of negative outcomes (adjusted hazard ratio: 0.84; 95% confidence interval: 0.73-0.97). Conclusion Buprenorphine was associated with the lowest risk of drug overdose-related hospitalization or ER visits among the MAT drugs. However, only 10.38% of OUD patients received MAT. Increasing MAT availability to patients with OUD is a key step toward preventing relapse and reducing adverse health outcomes.

Potential biomarker of brain response to opioid antagonism in adolescents with eating disorders: a pilot study

Background

Eating Disorders (ED) affect up to 5% of youth and are associated with reward system alterations and compulsive behaviors. Naltrexone, an opioid antagonist, is used to treat ED behaviors such as binge eating and/or purging. The presumed mechanism of action is blockade of reward activation; however, not all patients respond, and the optimal dose is unknown. Developing a tool to detect objective drug response in the brain will facilitate drug development and therapeutic optimization. This pilot study evaluated neuroimaging as a pharmacodynamic biomarker of opioid antagonism in adolescents with ED.

Methods

Youth aged 13-21 with binge/purge ED completed functional magnetic resonance imaging (fMRI) pre- and post-oral naltrexone. fMRI detected blood oxygenation-level dependent (BOLD) signal at rest and during two reward probes (monetary incentive delay, MID, and passive food view, PFV) in predefined regions of interest associated with reward and inhibitory control. Effect sizes for Δ%BOLD (post-naltrexone vs. baseline) were estimated using linear mixed effects modeling.

Results

In 12 youth (16-21 years, 92% female), BOLD signal changes were detected following naltrexone in the nucleus accumbens during PFV (Δ%BOLD -0.08 ± 0.03; Cohen's d -1.06, p = 0.048) and anterior cingulate cortex during MID (Δ%BOLD 0.06 ± 0.03; Cohen's d 1.25, p = 0.086).

Conclusion

fMRI detected acute reward pathway modulation in this small sample of adolescents with binge/purge ED. If validated in future, larger trials, task-based Δ%BOLD detected by fMRI may serve as a pharmacodynamic biomarker of opioid antagonism to facilitate the development of novel therapeutics targeting the reward pathway, enable quantitative pharmacology trials, and inform drug dosing.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT04935931, NCT#04935931.

A gender-based secondary analysis of the ADAPT-2 combination naltrexone and bupropion treatment for methamphetamine use disorder trial

BACKGROUND AND AIMS

Socio-cultural (gender) and biological (sex)-based differences contribute to psychostimulant susceptibility, potentially affecting treatment responsiveness among women with methamphetamine use disorder (MUD). The aims were to measure (i) how women with MUD independently and compared with men respond to treatment versus placebo and (ii) among women, how the hormonal method of contraception (HMC) affects treatment responsiveness.

DESIGN

This was a secondary analysis of ADAPT-2, a randomized, double-blind, placebo-controlled, multicenter, two-stage sequential parallel comparison design trial.

SETTING

United States.

PARTICIPANTS

This study comprised 126 women (403 total participants); average age = 40.1 years (standard deviation = 9.6) with moderate to severe MUD.

INTERVENTIONS

Interventions were combination intramuscular naltrexone (380 mg/3 weeks) and oral bupropion (450 mg daily) versus placebo.

MEASUREMENTS

Treatment response was measured using a minimum of three of four negative methamphetamine urine drug tests during the last 2 weeks of each stage; treatment effect was the difference between weighted treatment responses of each stage.

FINDINGS

At baseline, women used methamphetamine intravenously fewer days than men [15.4 versus 23.1% days, P = 0.050, difference = -7.7, 95% confidence interval (CI) = -15.0 to -0.3] and more women than men had anxiety (59.5 versus 47.6%, P = 0.027, difference = 11.9%, 95% CI = 1.5 to 22.3%). Of 113 (89.7%) women capable of pregnancy, 31 (27.4%) used HMC. In Stage 1 29% and Stage 2 5.6% of women on treatment had a response compared with 3.2% and 0% on placebo, respectively. A treatment effect was found independently for females and males (P < 0.001); with no between-gender treatment effect (0.144 females versus 0.100 males; P = 0.363, difference = 0.044, 95% CI = -0.050 to 0.137). Treatment effect did not differ by HMC use (0.156 HMC versus 0.128 none; P = 0.769, difference = 0.028, 95% CI -0.157 to 0.212).

CONCLUSIONS

Women with methamphetamine use disorder receiving combined intramuscular naltrexone and oral bupropion treatment achieve greater treatment response than placebo. Treatment effect does not differ by HMC.

Use of the opioid receptor antagonist - naltrexone in the treatment of non-suicidal self-injury

AIM

The aim of the study was to review the existing research, conducted on animal and human models, regarding the possibility of using low doses of naltrexone (LDN) in treatment of non-suicidal self-injury (NSSI).

METHOD

The available Polish - and English-language literature on NSSI was reviewed. Relevant studies were identified through an electronic search of PubMed/MEDLINE and Google Scholar databases using the following keywords: non-suicidal self-injury, NSSI, naltrexone, LDN, self-injury, self-harm, and time descriptors 1982-2022. The review was based on information reported in original papers, review articles and case reports. The quality of the article was assessed using the six-point Scale for the Assessment of Narrative Review Articles (SANRA).

RESULTS

Studies conducted on animal models show that use of LDN can prevent habitual self-injury. As far as the possibility of clinical use of LDN in treatment of NSSI is concerned, results of a relatively small number of studies conducted so far confirm the efficacy of using naltrexone 25-50 mg/day to decrease or eliminate self-injurious behaviors in NSSI patients.

CONCLUSIONS

The use of LDN in treatment of NSSI seems to be a promising clinical option, whose efficacy, however, needs to be corroborated in a larger number of randomized placebo-controlled clinical trials.

Opiate Antagonists for Chronic Pain: A Review on the Benefits of Low-Dose Naltrexone in Arthritis versus Non-Arthritic Diseases

Chronic pain conditions create major financial and emotional burdens that can be devastating for individuals and society. One primary source of pain is arthritis, a common inflammatory disease of the joints that causes persistent pain in affected people. The main objective of pharmacological treatments for either rheumatoid arthritis (RA) or osteoarthritis (OA) is to reduce pain. Non-steroidal anti-inflammatory drugs, opioids, and opioid antagonists have each been considered in the management of chronic pain in arthritis patients. Naltrexone is an oral-activated opioid antagonist with biphasic dose-dependent pharmacodynamic effects. The molecule acts as a competitive inhibitor of opioid receptors at high doses. However, naltrexone at low doses has been shown to have hormetic effects and provides relief for chronic pain conditions such as fibromyalgia, multiple sclerosis (MS), and inflammatory bowel disorders. Current knowledge of naltrexone suggests that low-dose treatments may be effective in the treatment of pain perception in chronic inflammatory conditions observed in patients with either RA or OA. In this review, we evaluated the therapeutic benefits of low-dose naltrexone (LDN) on arthritis-related pain conditions.

Precipitated withdrawal with kratom use following naltrexone administration

Kratom is an herbal supplement with reports of use for natural pain relief or treatment of opioid withdrawal symptoms. Kratom has metabolites that bind to and agonize mu-opioid receptors similar to opiate medications. There have been reports of serious adverse reactions, with a potential for dependence with long-term use and withdrawal that may occur upon discontinuation. Naltrexone can result in abrupt withdrawal symptoms when used with opioids or opioid-like supplements such as kratom. This case report describes withdrawal precipitated by naltrexone administration in a patient with undisclosed chronic kratom use. This case highlights the importance of thorough assessment of all self-administered herbal and over-the-counter supplements as they may have serious interactions with other prescribed medications and affect therapeutic outcomes.

Optimally Choosing Medication Type for Patients With Opioid Use Disorder

Patients with opioid use disorder (OUD) tend to get assigned to one of 3 medications based on the treatment program to which the patient presents (e.g., opioid treatment programs tend to treat patients with methadone, while office-based practices tend to prescribe buprenorphine). It is possible that optimally matching patients with treatment type would reduce the risk of return to regular opioid use (RROU). We analyzed data from 3 comparative effectiveness trials from the US National Institute on Drug Abuse Clinical Trials Network (CTN0027, 2006-2010; CTN0030, 2006-2009; and CTN0051 2014-2017), in which patients with OUD (n = 1,459) were assigned to treatment with either injection extended-release naltrexone (XR-NTX), sublingual buprenorphine-naloxone (BUP-NX), or oral methadone. We learned an individualized rule by which to assign medication type such that risk of RROU during 12 weeks of treatment would be minimized, and then estimated the amount by which RROU risk could be reduced if the rule were applied. Applying our estimated treatment rule would reduce risk of RROU compared with treating everyone with methadone (relative risk (RR) = 0.79, 95% confidence interval (CI): 0.60, 0.97) or treating everyone with XR-NTX (RR = 0.71, 95% CI: 0.47, 0.96). Applying the estimated treatment rule would have resulted in a similar risk of RROU to that of with treating everyone with BUP-NX (RR = 0.92, 95% CI: 0.73, 1.11).

In brief: Over-the-counter Narcan nasal spray

The FDA has approved the over-the-counter (OTC) sale of Narcan (Emergent), a nasal spray that delivers 4 mg of the opioid antagonist naloxone. Narcan nasal spray has been available by prescription since 2015 for emergency treatment of opioid overdose. Generic formulations of Narcan have also been approved; the manufacturers of these products will be required to switch them to OTC status and amend their labeling accordingly.1 Kloxxado, an 8-mg naloxone nasal spray, remains available only by prescription.

Pilot Study of Low-Dose Naltrexone for the Treatment of Chronic Pain Due to Arthritis: A Randomized, Double-blind, Placebo-Controlled, Crossover Clinical Trial

PURPOSE

Low-dose naltrexone (LDN) is commonly used to control pain and other symptoms, especially in patients with autoimmune diseases, but with limited evidence. This study tests the efficacy of LDN in reducing chronic pain in patients with osteoarthritis (OA) and inflammatory arthritis (IA), where existing approaches often fail to adequately control pain.

METHODS

In this randomized, double-blind, placebo-controlled, crossover clinical trial, each patient received 4.5 mg LDN for 8 weeks and placebo for 8 weeks. Outcome measures were patient reported, using validated questionnaires. The primary outcome was differences in pain interference during the LDN and placebo periods, using the Brief Pain Inventory (scale, 0-70). Secondary outcomes included changes in mean pain severity, fatigue, depression, and multiple domains of health-related quality of life. The painDETECT questionnaire classified pain as nociceptive, neuropathic, or mixed. Data were analyzed using mixed-effects models.

FINDINGS

Seventeen patients with OA and 6 with IA completed the pilot study. Most patients described their pain as nociceptive (n = 9) or mixed (n = 8) rather than neuropathic (n = 3). There was no difference in change in pain interference after treatment with LDN (mean [SD], -23 [19.4]) versus placebo (mean [SD], -22 [19.2]; P = 0.90). No significant differences were seen in pain severity, fatigue, depression, or health-related quality of life.

IMPLICATIONS

In this small pilot study, findings do not support LDN being efficacious in reducing nociceptive pain due to arthritis. Too few patients were enrolled to rule out modest benefit or to assess inflammatory or neuropathic pain.

CLINICALTRIALS

gov identifier: NCT03008590.