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.

Safety and tolerability of ALO-02 (oxycodone hydrochloride and sequestered naltrexone hydrochloride) extended-release capsules in older patients: a pooled analysis of two clinical trials

Objective: To assess the impact of age on the safety and tolerability of ALO-02, an abuse-deterrent opioid formulation consisting of oxycodone hydrochloride and sequestered naltrexone hydrochloride, in patients with chronic pain.Methods: Data from two clinical studies in patients with chronic low back pain or chronic non-cancer pain were analyzed. Patients aged ≥18 years who required continuous around-the-clock opioid analgesia for an extended period were grouped into ≥65 years and <65 years age groups. Treatment-emergent adverse events (TEAEs), use of concomitant medications, clinical laboratory measurements, and occurrences of opioid withdrawal using reported adverse events (AEs) and Clinical Opiate Withdrawal Scale (COWS) scores assessed safety. Data pooling was employed for the titration and maintenance phases of both studies.Results: Respectively 805 and 436 patients received ≥1 dose of ALO-02 in the titration and maintenance phases; 121 (15.0%) and 83 (14.6%) patients, respectively, were aged ≥65 years in the titration and maintenance phases. Average doses of ALO-02 were lower in the older patients in both phases. Incidences of TEAEs were comparable between age groups in both phases and generally lower in the maintenance phase. Concomitant medications were taken more often by patients aged ≥65 years. Incidences of potentially clinically significant laboratory results were low in both phases with no clinically important differences between age groups. There were few reports of opioid withdrawal events as assessed by reported AEs and COWS scores. One patient aged ≥65 years experienced an AE of opioid withdrawal.Conclusions: The safety and tolerability of ALO-02 is similar in those aged ≥65 years and those aged <65 years with chronic pain.ClinicalTrials.gov identifiers: NCT01571362, NCT01428583.

The lowdown on low-dose naltrexone

Low-dose naltrexone (LDN) has become a hot topic in many fields of medicine, including dermatology. It has gained popularity as an alternative, off-label treatment that works by targeting inflammation. Patients may ask you about LDN as a treatment option for a variety of inflammatory skin conditions, specifically in comparison to more traditional systemic treatments. It is important for dermatologists to know what LDN is, how it works, how to prescribe it, and what side effects should be monitored.

Optimising opioid substitution therapy in the prison environment

PURPOSE

The purpose of this paper is to examine the current provision of opioid substitution therapy (OST) during and immediately following release from detention in prisons in England and Wales.

DESIGN/METHODOLOGY/APPROACH

A group of experts was convened to comment on current practices and to make recommendations for improving OST management in prison. Current practices were previously assessed using an online survey and a focus group with experience of OST in prison (Webster, 2017).

FINDINGS

Disruption to the management of addiction and reduced treatment choice for OST adversely influences adequate provision of OST in prison. A key concern was the routine diversion of opiate substitutes to other prisoners. The new controlled drug formulations were considered a positive development to ensure streamlined and efficient OST administration. The following patient populations were identified as having concerns beyond their opioid use, and therefore require additional considerations in prison: older people with comorbidities and complex treatment needs; women who have experienced trauma and have childcare issues; and those with existing mental health needs requiring effective understanding and treatment in prison.

ORIGINALITY/VALUE

Integration of clinical and psychosocial services would enable a joint care plan to be tailored for each individual with opioid dependence and include options for detoxification or maintenance treatment. This would better enable those struggling with opioid use to make informed choices concerning their care during incarceration and for the period immediately following their release. Improvements in coordination of OST would facilitate inclusion of strategies to further streamline this process for the benefit of prisoners and prison staff.

Effects of Varenicline Alone and in Combination With Low-dose Naltrexone on Alcohol-primed Smoking in Heavy-drinking Tobacco Users: A Preliminary Laboratory Study

OBJECTIVES

Heavy-drinking tobacco users are less likely to successfully quit smoking than their moderate-drinking counterparts, even when they are prescribed smoking cessation medication. One strategy for improving treatment outcomes in this subgroup of tobacco users may be to combine medication therapies to target both alcohol and tobacco use simultaneously. Adding naltrexone to frontline smoking cessation treatments may improve treatment outcomes in this group.

METHOD

This double-blind, placebo-controlled human laboratory study examined the effects of varenicline (2 mg/d) and varenicline (2 mg/d), combined with a low dose of naltrexone (25 mg/d) on alcohol-primed smoking behavior in a laboratory model of smoking relapse in heavy-drinking tobacco users (n = 30). Participants attended a laboratory session and received an alcohol challenge (target breath alcohol concentration = 0.030 g/dL). They completed a smoking delay task that assessed their ability to resist smoking followed by an ad libitum smoking phase (primary outcomes). They also provided ratings of subjective drug effects and craving, and carbon monoxide levels were measured after smoking (secondary outcomes).

RESULTS

Participants receiving varenicline monotherapy delayed smoking longer and smoked fewer cigarettes than those on placebo. Participants receiving varenicline + low-dose naltrexone did not delay smoking longer than those receiving varenicline alone. Participants in both active medication arms smoked fewer cigarettes ad libitum than those receiving placebo.

CONCLUSIONS

Varenicline can improve smoking outcomes even after an alcohol prime, supporting its use in heavy drinkers who wish to quit smoking. Findings did not support increased efficacy of combined varenicline + low-dose naltrexone relative to varenicline monotherapy.

Opioid Use Disorder: Medical Treatment Options

Opioid use disorder is highly prevalent and can be fatal. At least 2.1 million Americans 12 years and older had opioid use disorder in 2016, and approximately 47,000 Americans died from opioid overdoses in 2017. Opioid use disorder is a chronic relapsing condition, the treatment of which falls within the scope of practice of family physicians. With appropriate medication-assisted treatment, patients are more likely to enter full recovery. Methadone and buprenorphine are opioid agonists that reduce mortality, opioid use, and HIV and hepatitis C virus transmission while increasing treatment retention. Intramuscular naltrexone is not as well studied and is harder to initiate than opioid agonists because of the need to abstain for approximately one week before the first dose. However, among those who start naltrexone, it can reduce opioid use and craving. Choosing the correct medication for a given patient depends on patient preference, local availability of opioid treatment programs, anticipated effectiveness, and adverse effects. Discontinuation of pharmacotherapy increases the risk of relapse; therefore, patients should be encouraged to continue treatment indefinitely. Many patients with opioid use disorder are treated in primary care, where effective addiction treatment can be provided. Family physicians are ideally positioned to diagnose opioid use disorder, provide evidence-based treatment with buprenorphine or naltrexone, refer patients for methadone as appropriate, and lead the response to the current opioid crisis.

Treating opioid dependence with extended-release naltrexone (XR-NTX) in Ukraine: Feasibility and three-month outcomes

BACKGROUND

Although opioid agonist treatments (OAT) with methadone or buprenorphine are available to treat opioid use disorders (OUD) in Ukraine, OAT acceptability and coverage remains low. Extended-release naltrexone (XR-NTX) that recently became available as another treatment option provides new opportunities for treating OUDs in this region and we aimed to test its feasibility.

METHODS

Patients with OUD (N=135) and interested in treatment with XR-NTX were initiated on monthly XR-NTX injections and monitored for three months. Correlates of 3-month retention on XR-NTX and drug use at each time-point using self-reports and urine drug testing (UDT) were assessed.

RESULTS

Of the 134 participants initiated XR-NTX, 101 (75%) completed three months, defined as 4 consecutive XR-NTX injections. Independent factors negatively associated with retention in XR-NTX treatment included previous maintenance with OAT (aOR=0.3; 95%CI=0.1-0.9) and extrinsic help-seeking treatment motivation (aOR=0.7; 95%CI=0.5-0.9). Of these 101 participants completing three months of treatment, opioid use markedly reduced using self-report (67%% to 22%; p>0.001) and UDT (77% to 24%; p<0.001) outcomes over time. Alcohol, marijuana and stimulant use, however, remained unchanged. Craving for opioids and symptoms of depression also significantly decreased, while health-related quality of life scores improved over time. No adverse side effects were reported during the period of observation.

CONCLUSION

The first introduction of XR-NTX in Ukraine among persons with OUD resulted in high levels of retention, marked reductions in opioid use and improved quality of life. These descriptive results suggest that XR-NTX treatment is feasible and well-tolerated over a 3-month period in Ukraine.

Low-dose naltrexone: a novel adjunctive treatment in symptomatic alopecias?

Naltrexone is a competitive antagonist of μ, κ and γ opioid receptors, used for treatment of alcoholism and opioid addiction. Low-dose naltrexone (LDN) is defined as daily doses ranging from 1mg to 5mg. This is purported to have a paradoxical effect that leads to an increase in endogenous opioids, including beta-endorphins, which have anti-inflammatory properties. Theses mechanisms may also justify their possible role in the treatment of inflammatory conditions. The aim of this article is to discuss the use of LDN as an adjuvant therapeutic option in symptomatic alopecias presenting with trichodynia. Trichodynia is defined as scalp discomfort of variable intensity presenting as diffuse or localized dysesthesia and may be described by patients as pain, pruritus, or burning. These are common symptoms in patients with hair loss that negatively impacts quality of life. Scalp discomfort may be refractory to conventional therapies and does not yet have a specific therapeutic guideline. For these cases, LDN would be a possible alternative to be added to the therapeutic arsenal owing to its anti-inflammatory properties, analgesic potential, low cost, and few adverse effects described. Further studies are needed to standardize dosing, better understand its mechanism of action, and evaluate its potential therapeutic indications.

Cross-talk between Human Spinal Cord μ-opioid Receptor 1Y Isoform and Gastrin-releasing Peptide Receptor Mediates Opioid-induced Scratching Behavior

BACKGROUND

Although spinal opioids are safe and effective, pruritus is common and distressing. The authors previously demonstrated in mouse spinal cord that interactions between μ-opioid receptor isoform 1D and gastrin releasing peptide receptor mediate morphine-induced scratch. The C-terminal of 1D inhibits morphine-induced scratch without affecting analgesia. The authors hypothesize that human spinal cord also contains itch-specific μ-opioid receptor isoforms which interact with gastrin releasing peptide receptor.

METHODS

Reverse transcription polymerase chain reaction was performed on human spinal cord complimentary DNA from two human cadavers. Calcium responses to morphine (1 μM) were examined using calcium imaging microscopy on human cells (HEK293) coexpressing gastrin releasing peptide receptor and different human μ-opioid receptor isoforms. The authors assessed morphine-induced scratching behavior and thermal analgesia in mice following intrathecal injection of morphine (0.3 nmol) and a transactivator of transcription peptide designed from C-terminal sequences of 1Y isoform (0, 0.1, and 0.4 nmol).

RESULTS

The authors demonstrated 1Y expression in the spinal cord dorsal horn. Morphine administration evoked a calcium response (mean ± SD) (57 ± 13 nM) in cells coexpressing both gastrin releasing peptide receptor and the 1Y isomer. This was blocked by 10 μM naltrexone (0.7 ± 0.4 nM; P < 0.0001), 1 μM gastrin-releasing peptide receptor antagonist (3 ± 2 nM; P < 0.0001), or 200 μM 1Y-peptide (2 + 2 nM; P < 0.0001). In mice, 0.4 nmol 1Y-peptide significantly attenuated morphine-induced scratching behaviors (scratching bouts, vehicle vs. 1Y-peptide) (92 ± 31 vs. 38 ± 29; P = 0.011; n = 6 to 7 mice per group), without affecting morphine antinociception in warm water tail immersion test (% of maximum possible effect) (70 ± 21 vs. 67 ± 22; P = 0.80; n = 6 mice per group).

CONCLUSIONS

Human μ-opioid receptor 1Y isomer is a C-terminal splicing variant of Oprm1 gene identified in human spinal cord. Cross-talk between 1Y and gastrin releasing peptide receptor is required for mediating opioid-induced pruritus. Disrupting the cross talk may have implications for therapeutic uncoupling of desired analgesic effects from side effects of opioids.

Low-dose naltrexone: a unique treatment for amyopathic dermatomyositis

Gottron papules, a heliotrope rash, scalp and extremity erythema, pruritus, and fatigue are the characteristic signs and symptoms of amyopathic dermatomyositis (ADM). Amyopathic dermatomyositis is considered a distinct entity from dermatomyositis (DM) because the characteristic muscle weakness and muscle enzyme elevations of DM are absent in ADM. With respects to treatment, ADM treatments have traditionally included topical corticosteroids and/or systemic immunosuppressants and immunomodulators. Herein we present a patient with refractory ADM that was responsive to low-dose naltrexone therapy.

Effectiveness of medication assisted treatment for opioid use in prison and jail settings: A meta-analysis and systematic review

This study examined the state of the literature on the effectiveness of medication assisted treatment (MAT; methadone, buprenorphine, naltrexone) delivered in prisons and jails on community substance use treatment engagement, opioid use, recidivism, and health risk behaviors following release from incarceration. Randomized controlled trials (RCTs) and quasi-experimental studies published through December 2017 that examined induction to or maintenance on methadone (n = 18 studies), buprenorphine (n = 3 studies), or naltrexone (n = 3 studies) in correctional settings were identified from PsycINFO and PubMed databases. There were a sufficient number of methadone RCTs to meta-analyze; there were too few buprenorphine or naltrexone studies. All quasi-experimental studies were systematically reviewed. Data from RCTs involving 807 inmates (treatment n = 407, control n = 400) showed that methadone provided during incarceration increased community treatment engagement (n = 3 studies; OR = 8.69, 95% CI = 2.46; 30.75), reduced illicit opioid use (n = 4 studies; OR = 0.22, 95% CI = 0.15; 0.32) and injection drug use (n = 3 studies; OR = 0.26, 95% CI = 0.12; 0.56), but did not reduce recidivism (n = 4 studies; OR = 0.93, 95% CI = 0.51; 1.68). Data from observational studies of methadone showed consistent findings. Individual review of buprenorphine and naltrexone studies showed these medications were either superior to methadone or to placebo, or were as effective as methadone in reducing illicit opioid use post-release. Results provide the first meta-analytic summary of MATs delivered in correctional settings and support the use of MATs, especially with regard to community substance use treatment engagement and opioid use; additional work is needed to understand the reduction of recidivism and other health risk behaviors.

The Affordable Care Act In The Heart Of The Opioid Crisis: Evidence From West Virginia

West Virginia is at the epicenter of a national opioid crisis, with a 2016 fatal opioid overdose rate of 43.4 per 100,000 population-more than triple the US average. We used claims data for 2014-16 to examine trends in treatment for opioid use disorder (OUD) among people enrolled in the West Virginia Medicaid expansion program under the Affordable Care Act. Expanding Medicaid could provide services to populations that may previously have had limited access to OUD treatment. We thus sought to understand trends over time in OUD diagnosis and treatment, especially with medications. About 5.5 percent of all enrollees were diagnosed with OUD per year, and the monthly prevalence of OUD diagnoses nearly tripled during this three-year period. The ratio of people filling buprenorphine to the number diagnosed with OUD was around one-third in early 2014, increasing to more than 75 percent by late 2016. Mean annual duration of filled buprenorphine increased from 161 days in 2014 to 185 days in 2016, and most people filling buprenorphine also received counseling and drug testing during the study period. The growing use of medication treatment for OUD in the West Virginia Medicaid expansion population provides an opportunity to reduce overdose deaths.

Behavioral and Accumbal Responses During an Affective Go/No-Go Task Predict Adherence to Injectable Naltrexone Treatment in Opioid Use Disorder

Adherence is a major factor in the effectiveness of the injectable extended-release naltrexone as a relapse prevention treatment in opioid use disorder. We examined the value of a variant of the Go/No-go paradigm in predicting extended-release naltrexone adherence in 27 detoxified opioid use disorder patients who were offered up to 3 monthly extended-release naltrexone injections. Before extended-release naltrexone, participants performed a Go/No-go task that comprised positively valenced Go trials and negatively valenced No-go trials during a functional magnetic resonance imaging scan. Errors of commission and neural responses to the No-go vs Go trials were independent variables. Adherence, operationalized as the completion of all 3 extended-release naltrexone injections, was the outcome variable. Fewer errors of commission and greater left accumbal response during the No-go vs Go trials predicted better adherence. These findings support the clinical potential of the behavioral and neurophysiological correlates of response inhibition in the prediction of extended-release naltrexone treatment outcomes in opioid use disorder.

Low Dose Naltrexone in Dermatology

Low-dose naltrexone (LDN) has been successfully studied as an immunomodulatory and anti-inflammatory therapy in a wide range of conditions including Crohn’s disease, fibromyalgia, major depressive disorder, cancer, chronic regional pain syndrome, Charcot-Marie-Tooth, and multiple sclerosis.1-5 Recently, off label LDN has been shown to improve dermatologic conditions such as systemic sclerosis, Hailey-Hailey Disease, lichen planopilaris, and guttate psoriasis.6-9 In this article, we examine the existing evidence for use of LDN in skin disease and discuss its potential application in the treatment of atopic dermatitis (AD). J Drugs Dermatol. 2019;18(3):235-238.

Factors influencing recruitment to a randomised placebo-controlled trial of oral naltrexone and extended release implant naltrexone: Qualitative study

AIMS

To understand the influences on recruitment to the Naltrexone Enhanced Addiction Treatment (NEAT) study, a randomised placebo-controlled trial of extended-release naltrexone (XR-NTX) implants for opioid use disorder (OUD), to learn lessons for the design and conduct of similar future research.

METHODS

29 face-to-face, semi-structured qualitative interviews were conducted with patients recruited to NEAT (n = 6), patients not recruited (n = 11), researchers who designed the trial (n = 5), and staff who delivered the trial (n = 7). The social marketing mix was used as a framework to guide the data analyses.

RESULTS

Dimensions of the 7Ps of the social marketing mix - product, price, place, promotion, physical environment, people, and processes all influenced recruitment to the NEAT trial. Among other things, the potential to receive a naltrexone implant (product); the provision of transport passes and shopping vouchers (price); clear verbal explanations (promotion); familiarity of the trial setting (physical environment); and approachable, friendly and informative trial delivery staff (people) positively influenced recruitment. Whereas, wanting a less medical approach to recovery (product); the perceived time, physical, and psychological costs of taking part (price); service ideological opposition to naltrexone in recovery (place); inaccessible written information (promotion); the location and nature of the trial setting (physical environment); a lack of knowledge about implants (people); and the blind allocation and potential of placebo (processes) deterred people from joining the trial.

CONCLUSIONS

Qualitative research informed by the social marketing mix as an analytical framework yielded detailed insights into understanding the factors and circumstances that influenced recruitment to the NEAT trial. Our findings have implications for the planning and implementation of future addiction trials, especially trials of extended-release formulations.

Serious adverse events reported in placebo randomised controlled trials of oral naltrexone: a systematic review and meta-analysis

BACKGROUND

Naltrexone is an opioid antagonist used in many different conditions, both licensed and unlicensed. It is used at widely varying doses from 3 to 250 mg. The aim of this review was to extensively evaluate the safety of oral naltrexone by examining the risk of serious adverse events and adverse events in randomised controlled trials of naltrexone compared to placebo.

METHODS

A systematic search of the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, other databases and clinical trials registries was undertaken up to May 2018. Parallel placebo-controlled randomised controlled trials longer than 4 weeks published after 1 January 2001 of oral naltrexone at any dose were selected. Any condition or age group was included, excluding only studies in opioid or ex-opioid users owing to possible opioid/opioid antagonist interactions. The systematic review used the guidance of the Cochrane Handbook and Preferred Reporting Items for Systematic Reviews and Meta-analyses harms checklist throughout. Numerical data were independently extracted by two people and cross-checked. Risk of bias was assessed with the Cochrane risk-of-bias tool. Meta-analyses were performed in R using random effects models throughout.

RESULTS

Eighty-nine randomised controlled trials with 11,194 participants were found, studying alcohol use disorders (n = 38), various psychiatric disorders (n = 13), impulse control disorders (n = 9), other addictions including smoking (n = 18), obesity or eating disorders (n = 6), Crohn's disease (n = 2), fibromyalgia (n = 1) and cancers (n = 2). Twenty-six studies (4,960 participants) recorded serious adverse events occurring by arm of study. There was no evidence of increased risk of serious adverse events for naltrexone compared to placebo (risk ratio 0.84, 95% confidence interval 0.66-1.06). Sensitivity analyses pooling risk differences supported this conclusion (risk difference -0.01, 95% confidence interval -0.02-0.00) and subgroup analyses showed that results were consistent across different doses and disease groups. Secondary analysis revealed only six marginally significant adverse events for naltrexone compared to placebo, which were of mild severity.

CONCLUSIONS

Naltrexone does not appear to increase the risk of serious adverse events over placebo. These findings confirm the safety of oral naltrexone when used in licensed indications and encourage investments to undertake efficacy studies in unlicensed indications.

TRIAL REGISTRATION

PROSPERO 2017 CRD42017054421 .

Neuroprotective effects of lipopolysaccharide and naltrexone co‑preconditioning in the photothrombotic model of unilateral selective hippocampal ischemia in rat

Preconditioning with lipopolysaccharide (LPS) or opioid antagonists has a neuroprotective effect in ischemic insults. However, the co‑preconditioning effect of toll‑like receptor ligands and opioid antagonists has not been investigated. In this study we examined the neuroprotective effect of LPS and naltrexone (NTX) preconditioning and co‑preconditioning in unilateral selective hippocampal ischemia in rats to assess for possible synergistic protective effects. LPS and NTX were injected unilaterally into the left cerebral ventricle of male rats. Forty‑eight hours after LPS and twenty‑four hours after NTX injection, ipsilateral selective hippocampal ischemia was induced using a modified version of the photothrombotic method. Protective effects for LPS and NTX were assessed by evaluating infarct volume (using 2,3,5‑triphenyltetrazolium chloride staining), and cognitive function (using radial arm water maze and passive avoidance tests). Animals in the ischemic group had an infarct lesion and considerable cognitive impairment, compared with the sham group. LPS or NTX preconditioning significantly reduced the infarct size and improved cognitive function. Moreover, co‑preconditioning with LPS and NTX increased the protective effect compared with preconditioning with LPS or NTX alone. Our data showed that LPS and NTX preconditioning resulted in a neuroprotective effect in hippocampal ischemia. Furthermore, co‑preconditioning with LPS and NTX resulted in a synergistic protective effect.

Facility-level changes in receipt of pharmacotherapy for opioid use disorder: Implications for implementation science

BACKGROUND

The U.S. is facing an opioid epidemic, but despite mandates for pharmacotherapy for opioid use disorder to be available at Veterans Health Administration (VHA) facilities, the majority of veterans with opioid use disorder do not receive these medications. In implementation research, facilities are often targeted for qualitative inquiry or quality improvement efforts based on quality measure performance during a one-year period. However, sites that experience quality performance changes from one year to the next may be highly informative because mechanisms that impact facility change may be more discoverable. The current study examined changes in receipt of pharmacotherapy for opioid use disorder in a national healthcare system to determine the extent to which sites fluctuated in performance over a two-year period and illustrate how changes in quality measures over time may be useful for implementation research and healthcare surveillance of quality measures.

METHODS

Using national VHA data from Fiscal Years (FY) 2016 and 2017, we calculated quality measure performance as the number of patients who received pharmacotherapy for opioid use disorder (i.e., methadone, buprenorphine, and naltrexone) divided by the number of patients with a current non-remitted opioid use disorder diagnosis for each FY at each facility (n = 129) and examined change from FY16 to FY17.

RESULTS

The mean rate of receipt of pharmacotherapy for opioid use disorder was 38% (facility range = 3% to 74%) in FY16 and 41% (facility range = 2% to 76%) in FY17. The average facility-level change in performance was 3% and ranged from -19% to 26%. There were 32 facilities that decreased in provision of pharmacotherapy, 12 facilities with no change, and 85 facilities that increased.

CONCLUSIONS

For facilities with average or high performance, it was difficult to maintain their performance over time. Identifying and learning from facilities with recent fluctuations may be more informative to guide the design of future quality improvement efforts than studying facilities with stable high or low performance.

Risk of hospitalisation and death related to baclofen for alcohol use disorders: Comparison with nalmefene, acamprosate, and naltrexone in a cohort study of 165 334 patients between 2009 and 2015 in France

PURPOSE

Baclofen is widely used off-label for alcohol use disorders (AUD) in France, despite its uncertain efficacy and safety, particularly at high doses. This study was designed to evaluate the safety of this off-label use compared to the main approved drugs for AUD (acamprosate, naltrexone, nalmefene).

METHODS

This cohort study from the French Health Insurance claims database included patients, aged 18 to 70 years, with no serious comorbidity (assessed by the Charlson score) initiating baclofen or approved drugs for AUD between 2009 and 2015. The risk of hospitalisation or death associated with baclofen, at variable doses over time (from low doses <30 mg/day to high doses ≥180 mg/day), compared to approved drugs, was evaluated by a Cox model adjusted to sociodemographic and medical characteristics.

RESULTS

The cohort included 165 334 patients, 47 614 of whom were exposed to baclofen. Patients exposed to baclofen differed from those treated with approved drugs in terms of sociodemographic and medical characteristics (more females, higher socioeconomic status, fewer hospitalisations for alcohol-related problems), but these differences tended to fade at higher doses of baclofen. Baclofen exposure was significantly associated with hospitalisation (hazard ratio [HR] = 1.13 [95%CI: 1.09-1.17]) and death (HR = 1.31 [95%CI: 1.08-1.60]). The risk increased with dose, reaching 1.46 [1.28-1.65] for hospitalisation and 2.27 [1.27-4.07] for death at high doses. Similar results were in patients with a history of hospitalisation for alcohol-related problems.

CONCLUSIONS

This study raises concerns about the safety of baclofen for AUD, particularly at high doses, with higher risks of hospitalisation and mortality than approved drugs.

Accounting for the uncounted: Physical and affective distress in individuals dropping out of oral naltrexone treatment for opioid use disorder

BACKGROUND

The theoretical benefits of naltrexone as a treatment for opioid use disorder (e.g., safety, non-addictive, low risk of diversion) stand in sharp contrast to its disappointing record on retention in most samples. The relationship of uncomfortable physical and dysphoric symptoms to retention on naltrexone is a controversial and under-studied issue.

METHODS

Using data from a randomized controlled trial of voucher-based contingency management and support from a significant other to enhance retention on oral naltrexone, we compared self-reported somatic and dysphoric symptoms, measured weekly, for individuals who were retained on naltrexone through the 12-week trial (n = 50) versus those who dropped out (n = 70).

RESULTS

There were no differences between participants who completed treatment and those who dropped out on multiple baseline characteristics, including somatic or affective symptoms prior to treatment. However, whether analyzed cross-sectionally or over time, participants who dropped out consistently reported higher rates of somatic symptoms, particularly difficulty sleeping, as well as affective symptoms, including multiple indicators of depression, anxiety, and anhedonia.

CONCLUSIONS

Although the smaller group of participants who were retained on oral naltrexone for 12 weeks reported decreasing physical and affective discomfort over time, there was substantial evidence that those who dropped out experienced continued and significant levels of distress. Individuals who report physical or affective distress while taking naltrexone may be at higher risk of dropout.

Clinical utility of the cold pressor test: evaluation of pain patients, treatment of opioid-induced hyperalgesia and fibromyalgia with low dose naltrexone

BACKGROUND

The cold pressor test (CPT) has been used in experimental paradigms to measure pain tolerance. It is used clinically to evaluate for opioid-induced hyperalgesia (OIH), as part of the clinical evaluation of fibromyalgia, to document reversal of OIH by low dose naltrexone (LDN), and to document the clinical response of fibromyalgia to LDN.

METHODS

We reviewed charts of 254 outpatients admitted to addiction medicine with chronic opioid treatment for pain, opioid addiction, or fibromyalgia. Controls were 46 non-addicted support persons. We invented the term "morphine years," a year at 60 mg/day, to estimate opioid exposure.

RESULTS

The mean age of patients was 41.4 years and controls 51.5. Age was not significantly correlated with CPT within each group. Female patients' mean CPT score (in seconds) was 35.0, male patients' 56.1, female controls' 110.8, male controls' 114.3. More morphine years correlated with younger age, more depression, higher prevalence of borderline personality disorder and attention deficit hyperactivity disorder, and low CPT. LDN increased CPT and reduced pain symptoms for both opioid users and fibromyalgia patients, with the increase being significantly higher for opioid users.

CONCLUSIONS

CPT is an objective complement to the subjective FACES pain scale. It gives an objective measure of changes in pain sensitivity accompanying administration of LDN. Limitations of a case series report are noted.

SIGNIFICANCE

CPT is shown to be an objective test of pain tolerance with clinical applications: evaluation of OIH, evaluation of fibromyalgia, reversal of OIH, protracted withdrawal with LDN, and amelioration of fibromyalgia with LDN.

The effect of naltrexone as a carboplatin chemotherapy-associated drug on the immune response, quality of life and survival of dogs with mammary carcinoma

The objective of this study was to evaluate the effect of low-dose naltrexone (LDN) as a carboplatin chemotherapy-associated drug in female dogs with mammary carcinoma in benign mixed tumors (MC-BMT) after mastectomy and to assess its association with quality of life and survival rates. Sixty female dogs were included in this study, all of which had histopathological diagnosis of MC-BMT and were divided into three groups: G1 (control), consisting of animals submitted only to mastectomy with or without regional metastasis; G2, composed of treated animals that did not present with metastasis; and G3, treated dogs that presented with metastasis. G2 and G3 were also subdivided according to the treatment administered: chemotherapy alone (MC-BMT(-) C/MC-BMT(+) C) or LDN and chemotherapy (MC-BMT(-) C+LDN/MC-BMT(+) C+LDN). All animals were subjected to clinical evaluation, mastectomy, peripheral blood lymphocyte immunophenotyping, beta-endorphin and met-enkephalin quantification, and evaluation of survival rates and quality of life scores. The results showed higher serum concentrations of beta-endorphin and met-enkephalin, fewer chemotherapy-related side effects, and better quality of life and survival rates in the LDN-treated groups than in LDN-untreated groups (P < 0.05). Evaluation of clinical and pathological parameters indicated a significant association between the use of LDN and both prolonged survival and enhanced quality of life. These results indicate that LDN is a viable chemotherapy-associated treatment in female dogs with MC-BMT, maintaining their quality of life and prolonging survival rates.

Pharmacotherapy for opioid addiction in community corrections

Pharmacotherapy for opioid addiction with methadone, buprenorphine, and naltrexone has proven efficacy in reducing illicit opioid use. These treatments are under-utilized among opioid-addicted individuals on parole, probation, or in drug courts. This paper examines the peer-reviewed literature on the effectiveness of pharmacotherapy for opioid addiction of adults under community-based criminal justice supervision in the US. Compared to general populations, there are relatively few papers addressing the separate impact of pharmacotherapy on individuals under community supervision. Tentative conclusions can be drawn from the extant literature. Reasonable evidence exists that illicit opioid use and self-reported criminal behaviour decline after treatment entry, and that these outcomes are as favourable among individuals under criminal justice supervision as the general treatment population. Surprisingly, there is no conclusive evidence regarding the extent to which pharmacotherapy impacts the likelihood of arrest and incarceration among individuals under supervision. However, given the proven efficacy of these three medications in reducing illicit opioid use and the evidence that, in the general population, methadone and buprenorphine treatment are associated with reduction in overdose mortality, the use of all three pharmacotherapies among patients under criminal justice supervision should be expanded while more data are collected on their impact on arrest and incarceration.

Naltrexone/bupropion for obesity

Naltrexone/bupropion (Mysimba - Orexigen Therapeutics Ireland Limited) is a fixed-dose combination product for the treatment of adults who are obese or overweight with at least one weight-related comorbidity, as an adjunct to diet and lifestyle modifications. Originally licensed by the European Medicines Agency (EMA) in 2015, it has recently been launched in the UK. Here, we review the evidence for its efficacy and safety and consider its place in therapy.

Patient predictors of substance use disorder treatment initiation in primary care

INTRODUCTION

Primary care clinics are opportune settings in which to deliver substance use disorder (SUD) treatment, but little is known about which patients initiate treatment in these settings.

METHODS

Using secondary data from a RCT that aimed to integrate SUD treatment into a federally qualified health center (FQHC) using an organizational readiness and collaborative care (CC) intervention, we examined patient-level predictors of initiation of evidence-based practices for opioid and/or alcohol use disorders (OAUDs): a brief behavioral treatment (BT) based on motivational interviewing and cognitive behavioral therapy and medication-assisted treatment (MAT) (extended-release injectable naltrexone (XR-NTX) for patients with an alcohol use disorder or opioid use disorder and buprenorphine/naloxone (BUP/NX) for patients with an opioid use disorder). Using the Andersen model of health care access, we tested bivariate and multivariate logistic regression models to assess associations between patient factors and initiation of BT and MAT.

RESULTS

Twenty-three percent of all participants (N = 392) received BT and 13% received MAT. In the multivariate model examining factors associated with initiation of BT, being of "other" or "multiple" races compared with being White (OR = 0.45, CI = 0.22, 0.92), being homeless (OR = 0.45, CI = 0.21, 0.97) and having been arrested within 90 days of baseline (OR = 0.21 CI = 0.63, 0.69) were associated with significantly lower odds of initiating BT. Greater self-stigma (OR = 1.60, CI = 1.06, 2.42), receiving MAT (OR = 5.52, CI = 2.34, 12.98), and having received the CC study intervention (OR = 12.95, CI = 5.91, 28.37) were associated with higher odds of initiating BT. In the multivariate model examining patient factors associated with initiating MAT, older age (OR = 1.07, CI = 1.03, 1.11), female gender (OR = 3.05, CI = 1.25, 7.46), having a diagnosis of heroin abuse or dependence (with or without alcohol abuse or dependence compared with have a diagnosis of alcohol dependence only (OR = 3.03, CI = 1.17, 7.86), and having received at least one session of BT (OR = 6.42, CI = 2.59, 15.94), were associated with higher odds of initiating MAT.

CONCLUSIONS

Individuals who initiate BT for OAUDs in a FQHC are less likely to be homeless and more likely to have greater self-stigma. Those who receive MAT are more likely to be of older age, female, and to have a diagnosis of heroin abuse or dependence, with or without concomitant alcohol abuse or dependence, rather than alcohol abuse or dependence alone. Receiving collaborative care (e.g., a warm handoff, and follow-up by a care coordinator) may be critical to initiating BT. Receiving at least one session of BT is associated with higher odds of receiving MAT, and receiving MAT is associated with higher odds of receiving BT. The Andersen model of health care access provides some insight into who initiates BT and MAT for OAUD treatment in FQHC-based primary care; further research is needed to explore system-level factors that may also influence treatment initiation.

The Use and Utility of Low-dose Naltrexone Capsules for Patients with Fibromyalgia

Fibromyalgia is a syndrome associated with chronic, widespread musculoskeletal pain, fatigue, depression, and cognitive dysfunction. With few U.S. Food and Drug Administration-approved treatment options, there is evidence that low-dose naltrexone, an opioid antagonist approved for opioid and alcohol dependence at high doses, may have efficacy in the treatment of fibromyalgia and chronic pain. At the doses required for fibromyalgia treatment, naltrexone needs to be compounded, and no data currently exists regarding the long-term stability of low-dose naltrexone capsules. This limits pharmacies to a maximum beyond-use date of 180 days. Our study examined the stability of compounded capsules of low-dose naltrexone in Avicel over 360 days. Naltrexone was extracted from compounded capsules and assessed using reversed-phase high-performance liquid chromatography validated to differentiate between the degraded and undegraded naltrexone. United States Pharmacopeia guidelines state that compounded medications must remain within 10% of the labeled potency at all times during the assigned expiration date for a preparation. Our results show that low-dose naltrexone is stable for 360 days when stored at room temperature and away from light remaining within 90% to 110% of the labeled potency throughout the study period. Based on our study results, the beyond-use date for compounded low-dose naltrexone formulations stored at room temperature and protected from light can be extended to 1 year. The longer beyond-use dating allows patients greater flexibility in using these capsules during the flare-ups associated with fibromyalgia without needing a refill immediately at the onset of symptoms. In addition, it may help compounding pharmacies reduce waste associated with small-batch preparation of these capsules.

Low dose naltrexone for induction of remission in Crohn's disease

BACKGROUND

Crohn's disease is a transmural, relapsing inflammatory condition afflicting the digestive tract. Opioid signalling, long known to affect secretion and motility in the gut, has been implicated in the inflammatory cascade of Crohn's disease. Low dose naltrexone, an opioid antagonist, has garnered interest as a potential therapy.

OBJECTIVES

The primary objective was to evaluate the efficacy and safety of low dose naltrexone for induction of remission in Crohn's disease.

SEARCH METHODS

A systematic search of MEDLINE, Embase, PubMed, CENTRAL, and the Cochrane IBD Group Specialized Register was performed from inception to 15 January 2018 to identify relevant studies. Abstracts from major gastroenterology conferences including Digestive Disease Week and United European Gastroenterology Week and reference lists from retrieved articles were also screened.

SELECTION CRITERIA

Randomized controlled trials of low dose naltrexone (LDN) for treatment of active Crohn's disease were included.

DATA COLLECTION AND ANALYSIS

Data were analyzed on an intention-to-treat basis using Review Manager (RevMan 5.3.5). The primary outcome was induction of clinical remission defined by a Crohn's disease activity index (CDAI) of < 150 or a pediatric Crohn's disease activity index (PCDAI) of < 10. Secondary outcomes included clinical response (70- or 100-point decrease in CDAI from baseline), endoscopic remission or response, quality of life, and adverse events as defined by the included studies. Risk ratios (RR) and 95% confidence intervals (CI) were calculated for dichotomous outcomes. The methodological quality of included studies was evaluated using the Cochrane risk of bias tool. The overall quality of the evidence supporting the primary outcome and selected secondary outcomes was assessed using the GRADE criteria.

MAIN RESULTS

Two studies were identified (46 participants). One study assessed the efficacy and safety of 12 weeks of LDN (4.5 mg/day) treatment compared to placebo in adult patients (N = 34). The other study assessed eight weeks of LDN (0.1 mg/kg, maximum 4.5 mg/day) treatment compared to placebo in pediatric patients (N = 12). The primary purpose of the pediatric study was to assess safety and tolerability. Both studies were rated as having a low risk of bias. The study in adult patients reported that 30% (5/18) of LDN treated patients achieved clinical remission at 12 weeks compared to 18% (3/16) of placebo patients, a difference that was not statistically significant (RR 1.48, 95% CI 0.42 to 5.24). The study in children reported that 25% of LDN treated patients achieved clinical remission (PCDAI < 10) compared to none of the patients in the placebo group, although it was unclear if this result was for the randomized placebo-controlled trial or for the open label extension study. In the adult study 70-point clinical response rates were significantly higher in those treated with LDN than placebo. Eighty-three per cent (15/18) of LDN patients had a 70-point clinical response at week 12 compared to 38% (6/16) of placebo patients (RR 2.22, 95% CI 1.14 to 4.32). The effect of LDN on the proportion of adult patients who achieved a 100-point clinical response was uncertain. Sixty-one per cent (11/18) of LDN patients achieved a 100-point clinical response compared to 31% (5/16) of placebo patients (RR 1.96, 95% CI 0.87 to 4.42). The proportion of patients who achieved endoscopic response (CDEIS decline > 5 from baseline) was significantly higher in the LDN group compared to placebo. Seventy-two per cent (13/18) of LDN patients achieved an endoscopic response compared to 25% (4/16) of placebo patients (RR 2.89; 95% CI 1.18 to 7.08). However, there was no statistically significant difference in the proportion of patients who achieved endoscopic remission. Endoscopic remission (CDEIS < 3) was achieved in 22% (4/18) of the LDN group compared to 0% (0/16) of the placebo group (RR 8.05; 95% CI 0.47 to 138.87). Pooled data from both studies show no statistically significant differences in withdrawals due to adverse events or specific adverse events including sleep disturbance, unusual dreams, headache, decreased appetite, nausea and fatigue. No serious adverse events were reported in either study. GRADE analyses rated the overall quality of the evidence for the primary and secondary outcomes (i.e. clinical remission, clinical response, endoscopic response, and adverse events) as low due to serious imprecision (sparse data).

AUTHORS' CONCLUSIONS

Currently, there is insufficient evidence to allow any firm conclusions regarding the efficacy and safety of LDN used to treat patients with active Crohn's disease. Data from one small study suggests that LDN may provide a benefit in terms of clinical and endoscopic response in adult patients with active Crohn's disease. Data from two small studies suggest that LDN does not increase the rate of specific adverse events relative to placebo. However, these results need to be interpreted with caution as they are based on very small numbers of patients and the overall quality of the evidence was rated as low due to serious imprecision. Further randomized controlled trials are required to assess the efficacy and safety of LDN therapy in active Crohn's disease in both adults and children.

Precision Medicine in Alcohol Dependence: A Controlled Trial Testing Pharmacotherapy Response Among Reward and Relief Drinking Phenotypes

Randomized trials of medications for alcohol dependence (AD) often report no differences between active medications. Few studies in AD have tested hypotheses regarding which medication will work best for which patients (ie, precision medicine). The PREDICT study tested acamprosate and naltrexone vs placebo in 426 randomly assigned AD patients in a 3-month treatment. PREDICT proposed individuals whose drinking was driven by positive reinforcement (ie, reward drinkers) would have a better treatment response to naltrexone, whereas individuals whose drinking was driven by negative reinforcement (ie, relief drinkers) would have a better treatment response to acamprosate. The goal of the current analysis was to test this precision medicine hypothesis of the PREDICT study via analyses of subgroups. Results indicated that four phenotypes could be derived using the Inventory of Drinking Situations, a 30-item self-report questionnaire. These were high reward/high relief, high reward/low relief, low reward/high relief, and low reward/low relief phenotypes. Construct validation analyses provided strong support for the validity of these phenotypes. The subgroup of individuals who were predominantly reward drinkers and received naltrexone vs placebo had an 83% reduction in the likelihood of any heavy drinking (large effect size). Cutoff analyses were done for clinical applicability: individuals are reward drinkers and respond to naltrexone if their reward score was higher than their relief score AND their reward score was between 12 and 31. Using naltrexone with individuals who are predominantly reward drinkers produces significantly higher effect sizes than prescribing the medication to a more heterogeneous sample.

Injectable naltrexone, oral naltrexone, and buprenorphine utilization and discontinuation among individuals treated for opioid use disorder in a United States commercially insured population

We investigated prescribing patterns for four opioid use disorder (OUD) medications: 1) injectable naltrexone, 2) oral naltrexone, 3) sublingual or oralmucosal buprenorphine/naloxone, and 4) sublingual buprenorphine as well as transdermal buprenorphine (which is approved for treating pain, but not OUD) in a nationally representative claims-based database (Truven Health MarketScan®) of commercially insured individuals in the United States. We calculated the prevalence of OUD in the database for each year from 2010 to 2014 and the proportion of diagnosed patient months on OUD medication. We compared characteristics of individuals diagnosed with OUD who did and did not receive these medications with bivariate descriptive statistics. Finally, we fit a Cox proportional hazards model of time to discontinuation of therapy as a function of therapy type, controlling for relevant confounders. From 2010 to 2014, the proportion of commercially insured individuals diagnosed with OUD grew by fourfold (0.12% to 0.48%), but the proportion of diagnosed patient-months on medication decreased from 25% in 2010 (0.05% injectable naltrexone, 0.4% oral naltrexone, 23.1% sublingual or oralmucosal buprenorphine/naloxone, 1.5% sublingual buprenorphine, and 0% transdermal buprenorphine) to 16% in 2014 (0.2% injectable naltrexone, 0.4% oral naltrexone, 13.8% sublingual or oralmucosal buprenorphine/naloxone, 1.4% sublingual buprenorphine, and 0.3% transdermal buprenorphine). Individuals who received medication therapy were more likely to be male, younger, and have an additional substance use disorder compared with those diagnosed with OUD who did not receive medication therapy. Those prescribed injectable naltrexone were more often male, younger, and diagnosed with additional substance use disorders compared with those prescribed other medications for opioid use disorder (MOUDs). At 30 days after initiation, 52% for individuals treated with injectable naltrexone, 70% for individuals treated with oral naltrexone, 31% for individuals treated with sublingual or oralmucosal buprenorphine/naloxone, 58% for individuals treated with sublingual buprenorphine, and 51% for individuals treated with transdermal buprenorphine discontinued treatment. In the Cox proportional hazard model, use of injectable naltrexone, oral naltrexone, sublingual buprenorphine, and transdermal buprenorphine were all associated with significantly greater hazard of discontinuing therapy beginning >30days after MOUD initiation (HR=2.17, 2.54, 1.15, and 2.21, respectively, 95% CIs 2.04-2.30, 2.45-2.64, 1.10-1.19, and 2.11-2.33), compared with the use of sublingual or oralmucosal buprenorphine/naloxone. This analysis demonstrates that the use of evidence-based medication therapies has not kept pace with increases in OUD diagnoses in commercially insured populations in the United States. Among those who have been treated, discontinuation rates >30days after initiation are high. The proportion treated with injectable naltrexone, oral naltrexone, and transdermal buprenorphine grew over time but remains small, and the discontinuation rates are higher among those treated with these medications compared with those treated with sublingual or oralmucosal buprenorphine/naloxone. In the face of the opioid overdose and addiction crisis, new efforts are needed at the provider, health system, and policy levels so that MOUD availability and uptake keep pace with new OUD diagnoses and OUD treatment discontinuation is minimized.

Oxytocin and Naltrexone Successfully Treat Hypothalamic Obesity in a Boy Post-Craniopharyngioma Resection

CONTEXT

Hypothalamic obesity, a treatment-resistant condition common to survivors of craniopharyngioma (CP), is strongly associated with a poor quality of life in this population. Oxytocin (OT), a hypothalamic neuropeptide, has been shown to play a role in the regulation of energy balance and to have anorexigenic effects in animal studies. Naltrexone (NAL), an opiate antagonist, has been shown to deter hedonic eating and to potentiate OT's effects.

DESIGN

In this parent-observed study, we tested the administration of intranasal OT for 10 weeks (phase 1), followed by a combination of intranasal OT and NAL for 38 weeks (phase 2) in a 13-year-old male with confirmed hypothalamic obesity and hyperphagia post-CP resection. Treatment resulted in 1) reduction in body mass index (BMI) z score from 1.77 to 1.49 over 10 weeks during phase 1; 2) reduction in BMI z score from 1.49 to 0.82 over 38 weeks during phase 2; 3) reduced hyperphagia during phases 1 and 2; 4) continued hedonic high-carbohydrate food-seeking in the absence of hunger during phases 1 and 2; and 5) sustained weight reduction during decreased parental monitoring and free access to unlocked food in the home during the last 10 weeks of phase 2.

CONCLUSION

This successful intervention of CP-related hypothalamic obesity and hyperphagia by OT alone and in combination with NAL is promising for conducting future studies of this treatment-recalcitrant form of obesity.