Naloxegol versus Methylnaltrexone for Opioid-Induced Constipation in Critically Ill Patients

BACKGROUND

Constipation impacts 58% to 83% of critically ill patients and is associated with increased time on mechanical ventilation, delirium, and increased length of stay (LOS) in the intensive care unit (ICU).

OBJECTIVE

The purpose of this study was to evaluate the efficacy of enteral naloxegol (NGL) versus subcutaneous methylnaltrexone (MNTX) for the management of opioid-induced constipation (OIC) in critically ill patients.

METHODS

A retrospective analysis was conducted on adult patients admitted to the ICU who received a parenteral opioid infusion for at least 4 hours and experienced no bowel movement (BM) within the 48-hour period preceding the administration of NGL or MNTX. The primary outcome was time to first BM from the start of NGL or MNTX therapy. Secondary outcomes included number of BMs 72 hours following NGL or MNTX administration, ICU LOS, and cost-effectiveness.

RESULTS

After exclusion criteria were applied, 110 and 51 patients were included in the NGL and MNTX groups, respectively. With a 10% noninferiority margin, NGL was noninferior to MNTX (Wald statistic = 1.67; P = 0.047). Median time to first BM was 23.7 hours for NGL and 18.3 hours for MNTX patients. Median LOS was 14 days (NGL) and 12 days (MNTX), and the average number of BMs in 72 hours was 3.9 for NGL and 3.8 for MNTX. Using wholesale acquisition cost (WAC), the cost per BM for NGL and MNTX was $21.74 and $170.00, respectively.

CONCLUSION AND RELEVANCE

This study determined that NGL and MNTX had similar time to BM. NGL appears to be a safe and effective alternative with cost-saving potential in treating OIC in critically ill patients.

Effect of Preadministration of Nalmefene on Sufentanil-Induced Cough During Induction of General Anesthesia in Patients Undergoing Breast Surgery: A Double-Blind Randomized Controlled Trial

Purpose

This study was designed to investigate the effects of preadministration of nalmefene before general anesthesia induction on sufentanil-induced cough (SIC) in patients undergoing breast surgery.

Patients and Methods

A total of 105 patients scheduled for elective breast surgery under general anesthesia were selected and randomly assigned into three groups: normal saline (Group C), low-dose nalmefene 0.1 μg·kg-1 (Group LN), and high-dose nalmefene 0.25 μg·kg-1 (Group HN). Sufentanil 0.5 μg·kg-1 was injected intravenously within 2 s after 5 min of intervention. The count and severity of cough within 2 min after sufentanil injection, as well as the time to first cough, were recorded. In addition, we also collected intraoperative hemodynamic data, postoperative pain scores, the incidence of receiving rescue analgesics, and side effects up to 24 h after surgery.

Results

Compared to Group C, the incidence of SIC was significantly lower in Group LN and HN (64.7% vs 30.3% and 14.7%, respectively; P < 0.001), but no significant difference was observed between the two groups (P=0.126). Compared to Group C, the risk factors decreased by 53.4% (95% confidence interval [CI] =0.181-0.735, P=0.008) in Group LN and by 75.9% (95% CI=0.432-0.898, P=0.001) in Group HN. Of the patients with SIC, less frequent SIC within 2 min after induction and a lower proportion of severe coughs were observed than Group C (P < 0.05), and no difference was detected between Group LN and HN. Additionally, the onset time to the first SIC did not differ significantly between the groups. Intraoperative hemodynamic data, postoperative pain scores, and side effects in the first 24 h did not differ among the groups.

Conclusion

Preadministration of nalmefene prior to induction of general anesthesia effectively suppressed SIC in patients undergoing breast surgery, without affecting intraoperative hemodynamic fluctuation and postoperative pain intensity.

Low-dose naltrexone for post-COVID fatigue syndrome: a study protocol for a double-blind, randomised trial in British Columbia

INTRODUCTION

A significant proportion of individuals suffering from post COVID-19 condition (PCC, also known as long COVID) can present with persistent, disabling fatigue similar to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-viral fatigue syndromes. There remains no clear pharmacological therapy for patients with this subtype of PCC, which can be referred to as post-COVID fatigue syndrome (PCFS). A low dose of the opioid antagonist naltrexone (ie, low-dose naltrexone (LDN)) has emerged as an off-label treatment for treating fatigue and other symptoms in PCC. However, only small, non-controlled studies have assessed LDN in PCC, so randomised trials are urgently required.

METHODS AND ANALYSIS

A prospective, randomised, double-blind, parallel arm, placebo-controlled phase II trial will be performed to assess the efficacy of LDN for improving fatigue in PCFS. The trial will be decentralised and open to eligible individuals throughout the Canadian province of British Columbia (BC). Participants will be recruited through the province-wide Post-COVID-19 Interdisciplinary Clinical Care Network (PC-ICCN) and research volunteer platform (REACH BC). Eligible participants will be 19-69 years old, have had a confirmed or physician-suspected SARS-CoV-2 infection at least 3 months prior and meet clinical criteria for PCFS adapted from the Institute of Medicine ME/CFS criteria. Individuals who are taking opioid medications, have a history of ME/CFS prior to COVID-19 or history of significant liver disease will be excluded. Participants will be randomised to an LDN intervention arm (n=80) or placebo arm (n=80). Participants in each arm will be prescribed identical capsules starting at 1 mg daily and follow a prespecified schedule for up-titration to 4.5 mg daily or the maximum tolerated dose. The trial will be conducted over 16 weeks, with assessments at baseline, 6, 12 and 16 weeks. The primary outcome will be fatigue severity at 16 weeks evaluated by the Fatigue Severity Scale. Secondary outcomes will include pain Visual Analogue Scale score, overall symptom severity as measured by the Patient Phenotyping Questionnaire Short Form, 7-day step count and health-related quality of life measured by the EuroQol 5-Dimension questionnaire.

ETHICS AND DISSEMINATION

The trial has been authorised by Health Canada and approved by The University of British Columbia/Children's and Women's Health Centre of British Columbia Research Ethics Board. On completion, findings will be disseminated to patients, caregivers and clinicians through engagement activities within existing PCC and ME/CFS networks. Results will be published in academic journals and presented at conferences.

TRIAL REGISTRATION NUMBER

NCT05430152.

Rapid Initiation of Injection Naltrexone for Opioid Use Disorder: A Stepped-Wedge Cluster Randomized Clinical Trial

Importance

Injectable extended-release (XR)-naltrexone is an effective treatment option for opioid use disorder (OUD), but the need to withdraw patients from opioid treatment prior to initiation is a barrier to implementation.

Objective

To compare the effectiveness of the standard procedure (SP) with the rapid procedure (RP) for XR-naltrexone initiation.

Design, Setting, and Participants

The Surmounting Withdrawal to Initiate Fast Treatment with Naltrexone study was an optimized stepped-wedge cluster randomized trial conducted at 6 community-based inpatient addiction treatment units. Units using the SP were randomly assigned at 14-week intervals to implement the RP. Participants admitted with OUD received the procedure the unit was delivering at the time of their admission. Participant recruitment took place between March 16, 2021, and July 18, 2022. The last visit was September 21, 2022.

Interventions

Standard procedure, based on the XR-naltrexone package insert (approximately 5-day buprenorphine taper followed by a 7- to 10-day opioid-free period and RP, defined as 1 day of buprenorphine at minimum necessary dose, 1 opioid-free day, and ascending low doses of oral naltrexone and adjunctive medications (eg, clonidine, clonazepam, antiemetics) for opioid withdrawal.

Main Outcomes and Measures

Receipt of XR-naltrexone injection prior to inpatient discharge (primary outcome). Secondary outcomes included opioid withdrawal scores and targeted safety events and serious adverse events. All analyses were intention-to-treat.

Results

A total of 415 participants with OUD were enrolled (mean [SD] age, 33.6 [8.48] years; 205 [49.4%] identified sex as male); 54 [13.0%] individuals identified as Black, 91 [21.9%] as Hispanic, 290 [69.9%] as White, and 22 [5.3%] as multiracial. Rates of successful initiation of XR-naltrexone among the RP group (141 of 225 [62.7%]) were noninferior to those of the SP group (68 of 190 [35.8%]) (odds ratio [OR], 3.60; 95% CI, 2.12-6.10). Withdrawal did not differ significantly between conditions (proportion of days with a moderate or greater maximum Clinical Opiate Withdrawal Scale score (>12) for RP vs SP: OR, 1.25; 95% CI, 0.62-2.50). Targeted safety events (RP: 12 [5.3%]; SP: 4 [2.1%]) and serious adverse events (RP: 15 [6.7%]; SP: 3 [1.6%]) were infrequent but occurred more often with RP than SP.

Conclusions and Relevance

In this trial, the RP of XR-naltrexone initiation was noninferior to the standard approach and saved time, although it required more intensive medical management and safety monitoring. The results of this trial suggest that rapid initiation could make XR-naltrexone a more viable treatment for patients with OUD.

Trial Registration

ClinicalTrials.gov Identifier: NCT04762537.

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

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.

Case Series of Individuals Treated With Naltrexone During Pregnancy for Opioid and/or Alcohol Use Disorder

OBJECTIVE

There is a lack of knowledge about the relative safety and efficacy of naltrexone for the treatment of pregnant individuals with opioid and/or alcohol use disorder, including the range of outcomes, in both the pregnant individual and the infant, over the course of peripartum period. Our objective was to describe these outcomes in a cohort of pregnant individuals on naltrexone.

METHODS

In this prospective case series, 7 pregnant individuals with opioid use disorder (OUD) or alcohol use disorder (AUD) treated with naltrexone were followed from pregnancy through 12 months after delivery. Clinical treatment protocols and outcomes related to safety and efficacy during pregnancy, delivery, and the postpartum period are described.

RESULTS

There were 4 pregnant individuals with OUD and 3 with AUD, of which 3 were managed with oral and 4 with extended-release naltrexone. The mean gestational age at study enrollment was 21.7 (SD, 12) weeks. Of the 7 participants, there was no return to nonprescribed opioid use and 2 who experienced a return to alcohol use over the course of the study. All individuals delivered vaginally at a mean of 37 weeks gestation without any peripartum pain difficulties. Five of the individuals (71.4%) remained on naltrexone 12 months after delivery. There were no reported fetal anomalies and one preterm delivery. None of the infants developed neonatal opioid withdrawal syndrome.

CONCLUSIONS

For pregnant individuals with OUD or AUD treated with naltrexone, there were low rates of return to nonprescribed use and reassuring pregnant person and infant outcomes to 12 months postpartum.

Efficacy and safety of low-dose naltrexone in painful diabetic neuropathy: A randomized, double-blind, active-control, crossover clinical trial

BACKGROUND

There is a need for newer therapies for chronic painful diabetic neuropathy as the existing drugs have their own limitations. Clinical trials on low-dose naltrexone (1-5 mg/d) showed efficacy and safety in certain chronic painful conditions, but not in painful diabetic neuropathy. Hence the present study was planned.

METHODS

Sixty-seven participants with painful diabetic neuropathy were randomized to receive either 2 mg naltrexone or 10 mg amitriptyline daily following a 2-week run-in period. The participants were followed up every 2 weeks for a total of 6 weeks. Up-titration was done (to 4 mg naltrexone or 25/50 mg amitriptyline) if the pain reduction was less than 20% on the visual analog scale (VAS) during the next follow-up visit. Efficacy was assessed using the change in VAS score at the end of 6 weeks from baseline. Safety was evaluated at each follow-up visit. After 2 weeks of washout period, the participants were crossed over to receive the comparator drug for another 6 weeks with similar evaluations.

RESULTS

The difference (confidence interval) in the change in VAS score between groups from baseline was 1.64 (-0.92 to 4.20) in per-protocol analysis and 1.5 (-1.11 to 4.13) in intention-to-treat analysis. Eight and fifty-two adverse events were reported in the naltrexone and amitriptyline groups, respectively (P < .001). The most common adverse events were mild diarrhea with naltrexone and somnolence with amitriptyline.

CONCLUSIONS

Low-dose naltrexone exhibited similar efficacy and a superior safety profile compared with amitriptyline in painful diabetic neuropathy.

Sublingual Buprenorphine-Naloxone Compared With Injection Naltrexone for Opioid Use Disorder: Potential Utility of Patient Characteristics in Guiding Choice of Treatment

OBJECTIVE

Sublingual buprenorphine-naloxone and extended-release injection naltrexone are effective treatments, with distinct mechanisms, for opioid use disorder. The authors examined whether patients' demographic and clinical characteristics were associated with better response to one medication or the other.

METHODS

In a multisite 24-week randomized comparative-effectiveness trial of assignment to buprenorphine-naloxone (N=287) compared with extended-release naltrexone (N=283) comprising inpatients planning to initiate medication treatment for opioid use disorder, 50 demographic and clinical characteristics were examined as moderators of the effect of medication assignment on relapse to regular opioid use and failure to initiate medication. Moderator-by-medication interactions were estimated using logistic regression with correction for multiple testing.

RESULTS

In the intent-to-treat sample, patients who reported being homeless had a lower relapse rate if they were assigned to receive extended-release naltrexone (51.6%) compared with buprenorphine-naloxone (70.4%) (odds ratio=0.45, 95% CI=0.22, 0.90); patients who were not homeless had a higher relapse rate if they were assigned to extended-release naltrexone (70.9%) compared with buprenorphine-naloxone (53.1%) (odds ratio=2.15, 95% CI=1.44, 3.21). In the subsample of patients who initiated medication, the interaction was not significant, with a similar pattern of lower relapse with extended-release naltrexone (41.4%) compared with buprenorphine (68.6%) among homeless patients (odds ratio=0.32, 95% CI=0.15, 0.68) but less difference among those not homeless (extended-release naltrexone, 57.2%; buprenorphine, 52.0%; odds ratio=1.24, 95% CI=0.80, 1.90). For failure to initiate medication, moderators were stated preference for medication (failure was less likely if the patient was assigned to the medication preferred), parole and probation status (fewer failures with extended-release naltrexone for those on parole or probation), and presence of pain and timing of randomization (more failure with extended-release naltrexone for patients endorsing moderate to severe pain and randomized early while still undergoing medically managed withdrawal).

CONCLUSIONS

Among patients with opioid use disorder admitted to inpatient treatment, homelessness, parole and probation status, medication preference, and factors likely to influence tolerability of medication initiation may be important in matching patients to buprenorphine or extended-release naltrexone.

Pharmacotherapies for the Treatment of Alcohol Use Disorders During Pregnancy: Time to Reconsider?

It is generally recommended that medications only be used in pregnancy where the potential harms to both the mother and foetus are outweighed by the potential benefits. Despite the known harms associated with alcohol consumption during pregnancy, the use of medication for the treatment of pregnant women with an alcohol use disorder (AUD) appears to be rare. This is likely due to the lack of available data regarding the safety of these medications in pregnancy. We reviewed the literature and weighed up the harms associated with alcohol use and AUD during pregnancy with the potential benefits of medications for AUD in pregnancy, including acamprosate, naltrexone and disulfiram. There is little published evidence to support the safety of medications for AUD in pregnancy. However, from the research available it is likely that only disulfiram has the potential to cause serious foetal harm. While further research is required, acamprosate and naltrexone do not appear to be associated with substantial risks of congenital malformations or other serious consequences. Given the potential risks associated with alcohol consumption during pregnancy, the use of acamprosate and naltrexone should be considered for the treatment of pregnant women with AUD based on the current evidence base, although more research is warranted.

Trends in Urine Drug Monitoring Among Persons Receiving Long-Term Opioids and Persons with Opioid Use Disorder in the United States

BACKGROUND

Practice guidelines recommend urine drug monitoring (UDM) at least annually in the setting of chronic opioid therapy as an objective assessment of substance use. However, empirical evidence on who gets tested and how often testing occurs is lacking.

OBJECTIVES

This study investigates 10-year UDM trends in the United States based on 2 factors: (1) the duration of prescription opioid treatment, and (2) having an opioid use disorder (OUD) diagnosis and medications for opioid use disorder (MOUD) prescriptions.

STUDY DESIGN

Observational cross-sectional study.

SETTING

Research was conducted using administrative claims data from Optum's deidentified Clinformatics Data Mart Database for the period 2007 to 2016. The dataset contained information on the plan enrollment and health care claims from 50 states and the District of Columbia.

METHODS

To examine trends in UDM based on the duration of prescription opioid treatment, persons receiving prescription opioid analgesics were categorized into 4 groups based on the number of days covered: (a) less than 90 days, (b) 90 to 179 days, (c) 180 to 269 days, and (d) at least 270 days. To examine trends based on an OUD diagnosis and MOUD prescriptions, persons diagnosed with OUD were identified and categorized based on the presence of MOUD prescriptions as follows: (a) OUD with buprenorphine (BPN) and naltrexone (NTX) in the same year; (b) OUD with BPN only; (c) OUD with NTX only; (d) OUD with chronic prescription opioid analgesics (>= 90 days); (e) OUD without prescription opioid analgesics, BPN, or NTX; and (f) chronic prescription opioid analgesics (>= 90 days) without an OUD diagnosis. For analysis, the percent receiving UDM was estimated per group per year. Then the data were restricted to those receiving at least one UDM to estimate the average number of UDM per person.

RESULTS

Data included an average of 364,485 persons per year receiving prescription opioid analgesics for chronic use, and 10,277 per year receiving an OUD diagnosis. Among those receiving prescription opioid analgesics, less than 50% received UDM. For those receiving at least one UDM, one additional UDM was performed per person as the duration of opioids increased by 90 days. Among persons with OUD, the percent receiving UDM was the highest for those receiving both BPN and NTX (87%), followed by those receiving BPN only (80%), chronic opioids (79%), NTX only (72%), and those not receiving any MOUD/opioids (54%).

LIMITATIONS

Methadone dispensing for OUD treatments was not captured in administrative claims data.

CONCLUSIONS

Although recommended for patients with chronic pain, UDM is provided less than half of the time for these patients. However, once patients received at least one UDM, they would continue to receive it on a fairly regular basis. Compared with those with chronic pain, persons diagnosed with OUD are more likely to receive UDM at a more frequent interval.

Bupropion and Naltrexone in Methamphetamine Use Disorder

BACKGROUND

The use of naltrexone plus bupropion to treat methamphetamine use disorder has not been well studied.

METHODS

We conducted this multisite, double-blind, two-stage, placebo-controlled trial with the use of a sequential parallel comparison design to evaluate the efficacy and safety of extended-release injectable naltrexone (380 mg every 3 weeks) plus oral extended-release bupropion (450 mg per day) in adults with moderate or severe methamphetamine use disorder. In the first stage of the trial, participants were randomly assigned in a 0.26:0.74 ratio to receive naltrexone-bupropion or matching injectable and oral placebo for 6 weeks. Those in the placebo group who did not have a response in stage 1 underwent rerandomization in stage 2 and were assigned in a 1:1 ratio to receive naltrexone-bupropion or placebo for an additional 6 weeks. Urine samples were obtained from participants twice weekly. The primary outcome was a response, defined as at least three methamphetamine-negative urine samples out of four samples obtained at the end of stage 1 or stage 2, and the weighted average of the responses in the two stages is reported. The treatment effect was defined as the between-group difference in the overall weighted responses.

RESULTS

A total of 403 participants were enrolled in stage 1, and 225 in stage 2. In the first stage, 18 of 109 participants (16.5%) in the naltrexone-bupropion group and 10 of 294 (3.4%) in the placebo group had a response. In the second stage, 13 of 114 (11.4%) in the naltrexone-bupropion group and 2 of 111 (1.8%) in the placebo group had a response. The weighted average response across the two stages was 13.6% with naltrexone-bupropion and 2.5% with placebo, for an overall treatment effect of 11.1 percentage points (Wald z-test statistic, 4.53; P<0.001). Adverse events with naltrexone-bupropion included gastrointestinal disorders, tremor, malaise, hyperhidrosis, and anorexia. Serious adverse events occurred in 8 of 223 participants (3.6%) who received naltrexone-bupropion during the trial.

CONCLUSIONS

Among adults with methamphetamine use disorder, the response over a period of 12 weeks among participants who received extended-release injectable naltrexone plus oral extended-release bupropion was low but was higher than that among participants who received placebo. (Funded by the National Institute on Drug Abuse and others; ADAPT-2 ClinicalTrials.gov number, NCT03078075.).

Naltrexone attenuates methamphetamine-induced behavioral sensitization and conditioned place preference in mice

Methamphetamine addiction causes serious public health problems worldwide. However, there is no effective medication licensed for methamphetamine addiction. The endogenous opioid system is considered to be a common substrate in drug addiction due to its regulation of dopamine release. In recent clinical trials, (-)-naltrexone, an opioid receptors and Toll-like receptor 4 antagonist, has exhibited encouraging findings for treating methamphetamine addiction; however, the understanding of its pharmacological mechanisms remains insufficient. By using mice models of behavioral sensitization and conditioned place preference (CPP), the present study was performed to investigate the effects of naltrexone on the methamphetamine-associated properties of incentive salience and reward-related memory, the two crucial factors for the development of addictive process and relapse. We found that naltrexone reduced single methamphetamine-induced hyperlocomotion in mice. In the paradigm of methamphetamine-induced behavioral sensitization paired with contextual cues in mice, naltrexone suppressed the development and expression of locomotor sensitization, suggesting the decrease in incentive salience to methamphetamine and context. In the methamphetamine-induced CPP paradigm in mice, naltrexone attenuated both the expression and methamphetamine-priming reinstatement of CPP response, suggesting the impairment of either contextual cue- or drug-induced retrieval of methamphetamine-associated memory. After the establishment of methamphetamine-induced CPP in mice, naltrexone treatment during the extinction training produced conditioned place adverse response, suggesting that naltrexone facilitated negative affection-associated extinction learning. Taken together, these findings demonstrate that naltrexone could intervene in the properties of incentive salience and reward-related memory in methamphetamine addiction, which may contribute to its therapeutic effects on methamphetamine addicts in clinical studies.

Dopaminergic and opioidergic regulation during anticipation and consumption of social and nonsocial rewards

The observation of animal orofacial and behavioral reactions has played a fundamental role in research on reward but is seldom assessed in humans. Healthy volunteers (N = 131) received 400 mg of the dopaminergic antagonist amisulpride, 50 mg of the opioidergic antagonist naltrexone, or placebo. Subjective ratings, physical effort, and facial reactions to matched primary social (affective touch) and nonsocial (food) rewards were assessed. Both drugs resulted in lower physical effort and greater negative facial reactions during reward anticipation, especially of food rewards. Only opioidergic manipulation through naltrexone led to a reduction in positive facial reactions to liked rewards during reward consumption. Subjective ratings of wanting and liking were not modulated by either drug. Results suggest that facial reactions during anticipated and experienced pleasure rely on partly different neurochemical systems, and also that the neurochemical bases for food and touch rewards are not identical.

Differences in Sociodemographic and Alcohol-Related Clinical Characteristics Between Treatment Seekers and Nontreatment Seekers and Their Role in Predicting Outcomes in the COMBINE Study for Alcohol Use Disorder

BACKGROUND

One of the challenges in early-stage clinical research aimed at developing novel treatments for alcohol use disorder (AUD) is that the enrolled participants are heavy drinkers, but do not seek treatment for AUD.

AIMS

To compare nontreatment seekers with alcohol dependence (AD) from 4 human laboratory studies conducted at Brown University (N = 240; 65.4% male) to treatment seekers with AD from the multisite COMBINE study (N = 1,383; 69.1% male) across sociodemographic and alcohol-related clinical variables and to evaluate whether the variables that significantly differentiate the 2 samples predict the 3 main COMBINE clinical outcomes: time to relapse, percent days abstinent (PDA), and good clinical outcome.

METHODS

Sample characteristics were assessed by parametric and nonparametric testing. Three regression models measured the association between the differing variables and the 3 main COMBINE clinical outcomes.

RESULTS

The nontreatment seekers, compared to the treatment seekers, were more ethnically diverse, less educated, single, and working part-time or unemployed (p's < 0.05); they met fewer DSM-IV AD criteria and had significantly lower scores on alcohol-related scales (p's < 0.05); they were less likely to have a father with alcohol problems (p < 0.0001) and had a significantly earlier age of onset and longer duration of AD (p's < 0.05); they also had significantly more total drinks, drinks per drinking day, heavy drinking days (HDD), and lower PDA in the 30 days prior to baseline (p's < 0.0001 to <0.05). Having more HDD in the 30 days prior to baseline predicted all of the 3 COMBINE clinical outcomes. All the other characteristics mentioned above that differed significantly between the 2 groups predicted at least 1 of the 3 COMBINE clinical outcomes, except for level of education, age of onset, and duration of AD.

CONCLUSIONS

The observed differences between groups should be considered in efforts across participant recruitment at different stages of the development of new treatments for AUD.

No change in the consumption of thyroid hormones after starting low dose naltrexone (LDN): a quasi-experimental before-after study

BACKGROUND

Low dose naltrexone (LDN) is reported to have beneficial effects in several autoimmune diseases. The purpose of this study was to examine whether starting LDN was followed by changes in the dispensing of thyroid hormones to patients with hypothyroidism.

METHODS

We performed a quasi-experimental before-after study based on the Norwegian Prescription Database. Study participants were identified by using reimbursement codes for hypothyroidism. Cumulative dispensed Defined Daily Doses and the number of users of triiodothyronine (T3) and levothyroxine (LT4) 1 year before and after the first LDN prescription was compared in three groups based on LDN exposure.

RESULTS

We identified 898 patients that met the inclusion criteria. There was no association between starting LDN and the subsequent dispensing of thyroid hormones. If anything, there was a tendency towards increasing LT4 consumption with increasing LDN exposure.

CONCLUSION

The results of this study do not support claims of efficacy of LDN in hypothyroidism.

Mobile van delivery of extended-release buprenorphine and extended-release naltrexone for youth with OUD: An adaptation to the COVID-19 emergency

The Youth Opioid Recovery Support (YORS) intervention is a novel treatment for young adults with opioid use disorder (OUD) that uses developmentally informed strategies to reduce barriers to treatment engagement. YORS strategies, such as home delivery of extended-release buprenorphine and extended-release naltrexone for OUD, are designed to increase engagement in treatment, but with the COVID-19 pandemic these strategies increase risk of virus exposure and spread to patients and staff entering homes. We present mobile van service delivery as a potential solution to continuing to provide low-barrier care for young adults with OUD while reducing risk associated with COVID-19. Initial feedback from patients and staff is positive and lays the groundwork to test feasibility and acceptability of this intervention rigorously in future work. Mobile van delivery of extended-release medications for OUD may be a promising treatment modification for mitigating risk of COVID-19, as well as a useful option for ongoing enhancement of care.

Evidence-Based Pharmacotherapies for Alcohol Use Disorder: Clinical Pearls

Pathologic alcohol use affects more than 2 billion people and accounts for nearly 6% of all deaths worldwide. There are three medications approved for the treatment of alcohol use disorder by the US Food and Drug Administration (FDA): disulfiram, naltrexone (oral and long-acting injectable), and acamprosate. Of growing interest is the use of anticonvulsants for the treatment of alcohol use disorder, although currently none are FDA approved for this indication. Baclofen, a γ-aminobutyric acid B receptor agonist used for spasticity and pain, received temporary approval for alcohol use disorder in France. Despite effective pharmacotherapies, less than 9% of patients who undergo any form of alcohol use disorder treatment receive pharmacotherapies. Current evidence does not support the use of pharmacogenetic testing for treatment individualization. The objective of this review is to provide knowledge on practice parameters for evidenced-based pharmacologic treatment approaches in patients with alcohol use disorder.

Nicolau syndrome following intramuscular naltrexone injection

There are a variety of possible adverse drug reactions that can have differing presentations. Recognizing these presentations and the temporal relationship between drug intake and reaction is essential in preventing severe and potentially fatal results. We present a patient who had a sudden post-injection inflammatory response consistent with Nicolau syndrome after a 6 month course of repeated intramuscular naltrexone injections.

Safety of oral naltrexone in HIV-positive men who have sex with men and transgender women with alcohol use disorder and initiating antiretroviral therapy

HIV disproportionately affects men who have sex with men (MSM) and transgender women (TW). These populations use alcohol more heavily than the general population, and alcohol use disorders (AUDs) are more prevalent among them. Naltrexone (NTX) has documented efficacy and safety as a medication-assisted therapy for AUD. Its use has not been well-examined in persons with HIV (PWH) newly initiating antiretroviral therapy (ART) where the possibility of hepatotoxicity may be increased when initating multiple new medications. This study assessed the safety of oral NTX treatment (50 mg daily) initiated concomitantly with antiretroviral therapy (ART) in a double-blind randomized placebo-controlled trial of NTX in MSM/TW in Lima, Peru among MSM and TW with AUD (AUDIT score ≥ 8). We analyzed adverse event data from ART-naïve participants (N = 155) who were randomized (2:1) to initiate ART plus NTX (N = 103) or ART plus placebo (N = 52). Participants were monitored for 24 weeks while taking ART plus NTX/placebo, followed by 24 weeks receiving ART alone. Over 48 weeks, 135 grade 2 or 3 adverse events were reported, resulting in 1.3 clinical adverse events per participant equally represented in both treatment and placebo arms. Two serious adverse events occurred among two participants receiving NTX; neither was attributed to the study medication. No significant differences were found in the proportion of subjects reporting any adverse events between treatment arms across all time-points. These results suggest NTX is safe in MSM/TW PWH with AUD newly initiating ART, as no excess of clinical adverse events or transaminase elevation was associated with NTX use.

Low-dose Naltrexone Therapy for Psoriasis

Safe, inexpensive, and convenient psoriasis therapy is desirable. Two recent case reports suggested that low-dose naltrexone is effective. Cases from our practice are presented in order to further the evidence of efficacy and safety of low-dose naltrexone in the treatment of psoriasis. Patients included 13 females, 2 males; mean age 57 years; mean psoriasis duration 16 years. Of the patients, 8 had psoriatic arthritis. In the past, 5 had completely failed and 10 had partially responded to =1 topical therapies. Patients used a self-assessed Likert scale on the effect of low-dose naltrexone on their psoriasis: 1 - worse; 2 - unchanged; 3 - slightly improved; 4 - somewhat improved; 5 - marked improvement. The response to 4.5 mg of oral naltrexone was as follows: 8/15 marked improvement; 2/15 somewhat improved; and 5/15 unchanged. Three adverse events included insomnia, diarrhea, and self-limited headache. Marked improvement was seen by 53% of the 15 patients. Low-dose naltrexone regulates lymphocyte responses, reduces cytokine production, and likely reduces mast cell activity. Low-dose naltrexone is safe, inexpensive, and appears be effective in this open-label study.

Physiologically-Based Pharmacokinetic Modeling for Predicting Drug Interactions of a Combination of Olanzapine and Samidorphan

A combination of the antipsychotic olanzapine and the opioid receptor antagonist samidorphan (OLZ/SAM) is intended to provide the antipsychotic efficacy of olanzapine while mitigating olanzapine-associated weight gain. As cytochrome P450 (CYP) 1A2 and CYP3A4 are the major enzymes involved in metabolism of olanzapine and samidorphan, respectively, physiologically-based pharmacokinetic (PBPK) modeling was applied to predict any drug-drug interaction (DDI) potential between olanzapine and samidorphan or between OLZ/SAM and CYP3A4/CYP1A2 inhibitors/inducers. A PBPK model for OLZ/SAM was developed and validated by comparing model-simulated data with observed clinical study data. Based on model-based simulations, no DDI between olanzapine and samidorphan is expected when administered as OLZ/SAM. CYP3A4 inhibition is predicted to have a weak effect on samidorphan exposure and negligible effect on olanzapine exposure. CYP3A4 induction is predicted to reduce both samidorphan and olanzapine exposure. CYP1A2 inhibition or induction is predicted to increase or decrease, respectively, olanzapine exposure only.

Prevention and management of diarrhea associated with naldemedine among patients receiving opioids: a retrospective cohort study

BACKGROUND

Naldemedine, a novel peripherally-acting mu-opioid receptor antagonist, has improved opioid-induced constipation in randomized controlled trials. The most frequent adverse event of naldemedine is diarrhea, which can cause abdominal pain and often leads to treatment discontinuation. We aimed to identify risk factors and appropriate management strategies for key adverse events including diarrhea associated with naldemedine, since those have not been extensively studied.

METHODS

We conducted a multi-center retrospective cohort study. Eligible patients had cancer, had undergone palliative care at participating centers, had been prescribed regular opioids, and had taken at least one dose of naldemedine between June 2017 and March 2018. The primary endpoint was the incidence of diarrhea according to baseline characteristics. Secondary endpoints included the duration of naldemedine administration, daily defecation counts before and after starting naldemedine, duration and severity of diarrhea as an adverse event of naldemedine, other adverse events, and the incidence of constipation within 7 days after recovery from diarrhea. We defined patients who started naldemedine within three days of starting a regularly prescribed opioid as the early group, and the remainder as the late group.

RESULTS

Among 103 patients who received naldemedine, 98 fulfilled the eligibility criteria. The median age was 68 years and 48% of the patients were female. Median performance status was 3, and the median oral intake was 50%. The median duration of naldemedine administration and overall survival were 25 and 64 days, respectively. The incidence of diarrhea in the early group (n = 26) was significantly lower than in the late group (n = 72) (3.9% vs. 22.2%, p = 0.02). Daily defecation counts increased after late (median 0.43 to 0.88, p < 0.001), but remained stable after early naldemedine administration (median 1.00 to 1.00, p = 0.34). Constipation after the diarrhea was resolved was common (53%), especially among patients who stopped naldemedine (78%). The diarrhea was improved within three days in 92% of patients who stopped other laxatives.

CONCLUSIONS

The early administration of naldemedine is beneficial because it reduces adverse events including diarrhea. Diarrhea caused by naldemedine can be effectively managed by stopping other laxatives while continuing naldemedine.

The effect of low-dose naltrexone on solid Ehrlich carcinoma in mice: The role of OGFr, BCL2, and immune response

AIMS

Cancer is a major worldwide health problem. Cancer cells express opioid growth factor (OGF) which controls their growth. Naltrexone in low dose (LDN) blocks opioid receptors intermittently and controls the replication of cancer cells. The aim of this study was to investigate the effect of LDN and its chemotherapeutic additive effect on the growth of solid Ehrlich carcinoma in mice with focus on the OGFr and immune responses.

MAIN METHODS

Sixty female Swiss albino mice were assigned into 5 groups (n: 12 mice each): (i): normal control, (ii): Solid Ehrlich carcinoma (SEC), (iii): SEC treated with LDN, (iv): SEC treated with 5-fluorouracil (5-FU), (v): SEC treated with LDN + 5-FU. All drugs were started when the tumor became palpable on 9th day. At the end of the study animals were sacrificed, blood and tissue samples were collected. Tumor weight and volume were measured. Splenocytes and myeloid derived suppressor cells (MDSC) were counted. Tumor expression of opioid growth factor receptors (OGFr), serum level of IFN-γ, tumor histopathology (H&E) and immunohistochemistry staining of p21, p53, Bcl2 were assessed.

KEY FINDINGS

All drug-treated groups showed reduction in tumor weight and volume, significant increase of splenocyte with tendency to reduce MDSC cell counts. LDN led to significant increase in OGFr both in solo and in combination with 5FU. Serum IFN-γ is significantly increased by LDN but decreased by 5-FU. Also, LDN and 5FU increased immunehistochemical staining of p21 while decreased immunostaining of Bcl2. In animals treated with a combination of LDN and 5FU a maximal downregulation of the antiapoptotic mediator BCL2 was observed.

SIGNIFICANCE

The current study suggested that LDN may play a role in inhibiting cancer cell growth and highlights the possibility of promising combination with cancer chemotherapeutics, which guarantee further clinical studies for approval.

Medications for Opioid Use Disorder: A Guide for Physicians

The opioid crisis has shaped the national public health dialogue for some time now. A "call to action" is a strong and resounding cry from multiple disciplines. This piece intends to detail the nuts and bolts of prescribing medications used for the treatment of opioid use disorder. The underlying message here is that opioid use disorder is a chronic, treatable illness and physicians of all specialties have a responsibility to not turn a blind eye.