A systematic review of the effectiveness of naltrexone in the maintenance treatment of opioid and alcohol dependence

Evidence of subgroup differences in meta-analyses evaluating medications for alcohol use disorder: An umbrella review

Randomized controlled trials (RCTs) evaluating medications for alcohol use disorder (AUD) often examine heterogeneity of treatment effects through subgroup analyses that contrast effect estimates in groups of patients across individual demographic, clinical, and study design-related characteristics. However, these analyses are often not prespecified or adequately powered, highlighting the potential role of subgroup analyses in meta-analysis. Here, we conducted an umbrella review (i.e., a systematic review of meta-analyses) to determine the range and characteristics of reported subgroup analyses in meta-analyses of AUD medications. We searched PubMed to identify meta-analyses of RCTs evaluating medications for the management of AUD, alcohol abuse, or alcohol dependence in adults. We sought studies that measured drinking-related outcomes; quality of life, function, and rates of mortality; adverse events; and dropout. We considered meta-analyses that reported the results from formal subgroup analyses (comparing the summary effects across subgroup levels); summary effect estimates stratified across subgroup levels; and meta-regression, regression, or correlation-based subgroup analyses. We analyzed nine meta-analyses that included 61 formal subgroup analyses (median = 6 per meta-analysis), of which 33 (54%) were based on baseline participant-level and 28 (46%) were based on trial-level characteristics. Of the 58 subgroup analyses with either a p-value from a subgroup test or a statement by the authors that the subgroup analyses were not statistically significant, eight (14%) were statistically significant at the p < 0.05 level. Twelve meta-analyses reported the results of 102 meta-regression analyses, of which 25 (25%) identified statistically significant predictors of the relevant outcome of interest; nine (9%) were based on baseline participant-level and 93 (91%) were based on trial characteristics. Subgroup analyses across meta-analyses of AUD medications often focus on study-level characteristics, which may not be as clinically informative as subgroup analyses based on participant-level characteristics. Opportunities exist for future meta-analyses to standardize their subgroup methodology, focus on more clinically informative participant-level characteristics, and use predictive approaches to account for multiple relevant variables.

Molecular mechanisms of alcohol's effects on the human body: A review and update

Alcohol consumption has been linked to numerous negative health outcomes although it has some beneficial effects on moderate dosages, the most severe of which being alcohol-induced hepatitis. The number of people dying from this liver illness has been shown to climb steadily over time, and its prevalence has been increasing. Researchers have found that alcohol consumption primarily affects the brain, leading to a wide range of neurological and psychological diseases. High-alcohol-consumption addicts not only experienced seizures, but also ataxia, aggression, social anxiety, and variceal hemorrhage that ultimately resulted in death, ascites, and schizophrenia. Drugs treating this liver condition are limited and can cause serious side effects like depression. Serine-threonine kinases, cAMP protein kinases, protein kinase C, ERK, RACK 1, Homer 2, and more have all been observed to have their signaling pathways disrupted by alcohol, and alcohol has also been linked to epigenetic changes. In addition, alcohol consumption induces dysbiosis by changing the composition of the microbiome found in the gastrointestinal tract. Although more studies are needed, those that have been done suggest that probiotics aid in keeping the various microbiota concentrations stable. It has been argued that reducing one's alcohol intake may seem less harmful because excessive drinking is a lifestyle disorder.

Common strategies in empirically supported psychological interventions for alcohol use disorders: A meta-review

ISSUES

Despite the large number of effective psychological interventions for alcohol use disorders (AUD), there is still a lack of clarity concerning the strategies that make these interventions effective.

APPROACH

The overall goal of this review was to identify, examine and synthesise the information about common strategies from evidence-based psychological interventions for AUDs by conducting a review of systematic reviews, that is, a meta-review. We isolated the relevant primary studies from eligible systematic reviews and extracted information about the interventions from these studies to understand the strategies used. Analysis was restricted to narrative summaries.

KEY FINDINGS

Thirteen reviews were eligible for inclusion in our meta-review. Of these, eight demonstrated the effectiveness of a range of psychological interventions-behavioural couples therapy, cognitive behaviour therapy combined with motivational interviewing, brief interventions, contingency management, psychotherapy plus brief interventions, Alcoholics Anonymous and 12-step treatment programs, family-therapy or family-involved treatment, and community reinforcement approach. The most commonly used component strategies in effective interventions for AUDs included assessment, personalised feedback, motivational interviewing, goal setting, setting and review of homework, problem solving skills and relapse prevention/management.

IMPLICATIONS

Evidence about commonly used strategies in evidence-based psychological interventions for AUDs offer the possibility of creating menu-driven interventions that can be tailored to respond to individual client needs and preferences in different contexts.

Can we enhance the clinical efficacy of cognitive and psychological approaches to treat substance use disorders through understanding their neurobiological mechanisms?

Despite decades of research in the field of addiction, relapse rates for substance use disorders remain high. Consequently, there has been growing focus on providing evidence-based treatments for substance use disorders, resulting in the increased development and use of cognitive and psychological interventions. Such treatment approaches, including contingency management, community-reinforcement approach, and cognitive bias modification, have shown promising clinical efficacy in reducing substance use and promoting abstinence during treatment. However, these interventions are still somewhat limited in achieving sustained periods of abstinence post-treatment. The neurobiological mechanisms underpinning these treatment approaches remain largely unknown and under-studied, in part, due to a lack of translational animal models. The adoption of a reverse translational approach may assist in development of more representative models that can facilitate elucidation of the mechanisms behind these clinically relevant interventions. This review examines our current understanding of addiction neurobiology from clinical, preclinical research and existing animal models, and considers how the efficacy of such behavioral-oriented interventions alone, or in combination with pharmacotherapy, may be enhanced to improve treatment outcomes.

The Added Value of Pharmacotherapy to Cognitive Behavior Therapy And Vice Versa in the Treatment of Alcohol Use Disorders: A Systematic Review

AIM

To explore whether combined interventions i.e. psychotherapeutic plus psychosocial interventions are more effective than monotherapies in the treatment of alcohol use disorders.

METHODS

Systematic review of the results of randomized controlled trials that compared combined therapies with monotherapies (either pharmacotherapy or psychotherapy).

RESULTS

The search resulted in 28 eligible studies. Data from these RCTs showed that 10 out of 19 RCTs (53%) demonstrated an added value of combined therapy (psychotherapy + pharmacotherapy) compared to psychotherapy only, whereas only three out of nine RCTs (33%) comparing combined therapy with pharmacotherapy showed a possible added value for combined therapy.

CONCLUSIONS

Pharmacotherapy is effective to treat AUD with or without psychotherapy and that psychotherapy can best be offered in combination with pharmacotherapy.

Efficacy of Extended-Release Injectable Naltrexone on Alcohol Use Disorder Treatment: A Systematic Review

Alcohol use disorder (AUD) is a serious public health problem. Over 3.3 million people worldwide die each year due to alcohol-related causes, which is almost 5.3% of all deaths. This systematic review examines the effectiveness of injectable naltrexone treatment for people with AUD based on randomized clinical trial studies conducted between January 2004 and December 2019. Following PRISMA-P, this review searched PubMed, PsycINFO, CINAHL, Cochrane Library, and Web of Science for relevant studies. The inclusion criteria were AUD treatment, injectable naltrexone, and randomized clinical trials. Only articles written in English, involving human participants, and published in peer-reviewed journals were considered for this review. A total of 11 studies met the inclusion criteria. Ten out of the 11 studies assessed the impact of injectable naltrexone in a 3- to 6-month follow-up period, with one study having a year follow-up. This systematic review indicates that overall, injectable naltrexone therapy produced positive AUD treatment outcomes, including reduced mean time to first drinking day and/or heavy drinking day, decreased number of drinking and/or heavy drinking days, and increased abstinence, frequently at a statistically significant level in the larger studies. However, in all studies, less than half of the participants were completely abstinent after receiving injectable naltrexone. Injectable naltrexone treatment along with psychosocial therapy holds promise for addressing AUD.

Rapid and simple LC–MS/MS determination of urinary ethyl glucuronide, naltrexone, 6β-naltrexol, chlordiazepoxide, and norchlordiazepoxide for monitoring alcohol abuse

In this study, a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed to detect ethyl glucuronide (EtG), which is a biomarker for monitoring alcohol consumption, and naltrexone (NTX), 6β-naltrexol (6βNTX), chlordiazepoxide (CDP), and norchlordiazepoxide (norCDP), which are analyzed to confirm the presence of medications for alcohol dependence treatment. The protein precipitation method was conducted to rapidly prepare samples. LC–MS/MS analysis was performed in the multiple-reaction monitoring mode. The analytes were separated using a Scherzo SM-C18 (2.0 × 100 mm, 3 µm) column. The calibration ranges were 5–1000 ng/mL for EtG, 6βNTX, CDP, and norCDP, and 1–100 ng/mL for NTX, with the correlation coefficients (r) being ≥ 0.994, and the weighting factor being 1/x2. The lower limit of quantification was 1–5 ng/mL. The method was also validated for precision, accuracy, selectivity, dilution integrity, recovery, matrix effect, and stability. The developed method was successfully applied for the determination of EtG, NTX, 6βNTX, CDP, and norCDP in urine samples obtained from 49 probationers who received alcohol dependence treatment orders. The method developed herein can be used to monitor the drug-based treatment of alcohol abuse and alcohol consumption during the treatment of individuals under probation.

Naturalistic follow-up after a trial of medications for opioid use disorder: Medication status, opioid use, and relapse

AIM

This report examined naturalistic opioid use outcomes and utilization of medications for opioid use disorder (MOUD) 36 weeks post-randomization in the National Drug Abuse Treatment Clinical Trials Network (CTN) Extended-Release Naltrexone (XR-NTX) versus Buprenorphine-Naloxone (BUP-NX) for Opioid Treatment trial (CTN-0051, X:BOT).

DESIGN

X:BOT was a multisite, randomized, 24-week comparative effectiveness trial of BUP-NX (N = 287) and XR-NTX (N = 283). Study medications were discontinued following treatment completion, relapse, or dropout. Participants were encouraged to continue MOUD. This report examined opioid use outcomes in 428 (75%) of the 570 participants who attended the 36-week follow-up visit.

SETTING AND PARTICIPANTS

Adults with opioid use disorder recruited from 8 community treatment programs across the United States.

MEASUREMENTS

Outcomes included medication status (on/off MOUD), type of MOUD (BUP-NX, XR-NTX, or methadone), abstinence from non-prescribed opioids, opioid use days, relapse, and other substance use 30 days prior to the 36-week visit. Relapse was defined as opioid use for 4 consecutive weeks or 7 consecutive days in the past month. Baseline and clinical variables included opioid use severity, intravenous drug use, study medication assignment, and induction status.

FINDINGS

Of the 428 participants who completed the 36-week visit, 225 (53%) of participants were receiving MOUD and 203 (47%) were not. Compared to those off medication, participants on medication had fewer opioid use days (4.4 days (SD 9.0) versus 9.8 days (SD 12.1)), fewer met relapse criteria (37 (16.4%) versus 79 (38.9%)), and reported less stimulant use (34 (15.2%) versus 56 (27.7%)) and sedative use (14 (6.3%) versus 31 (15.3%)). There was no difference in abstinence rates between those on or off MOUD. A greater proportion of participants on XR-NTX (47 (53.4%) of 88 participants) were abstinent from non-prescribed opioids compared to those on buprenorphine (28 (23.3%) of 120 participants).

CONCLUSIONS

Naturalistic outcomes data showed that despite potential barriers to continuing treatment in the community, about half of individuals were on opioid use disorder pharmacotherapy at follow-up and those on medication generally had better outcomes. Future research should explore barriers and facilitators to treatment retention in community settings; and developing interventions tailored to improve treatment engagement and adherence.

A comprehensive review of prioritised interventions to improve the health and wellbeing of persons with lived experience of homelessness

Background

Homelessness has emerged as a public health priority, with growing numbers of vulnerable populations despite advances in social welfare. In February 2020, the United Nations passed a historic resolution, identifying the need to adopt social-protection systems and ensure access to safe and affordable housing for all. The establishment of housing stability is a critical outcome that intersects with other social inequities. Prior research has shown that in comparison to the general population, people experiencing homelessness have higher rates of infectious diseases, chronic illnesses, and mental-health disorders, along with disproportionately poorer outcomes. Hence, there is an urgent need to identify effective interventions to improve the lives of people living with homelessness.

Objectives

The objective of this systematic review is to identify, appraise, and synthesise the best available evidence on the benefits and cost-effectiveness of interventions to improve the health and social outcomes of people experiencing homelessness.

Search Methods

In consultation with an information scientist, we searched nine bibliographic databases, including Medline, EMBASE, and Cochrane CENTRAL, from database inception to February 10, 2020 using keywords and MeSH terms. We conducted a focused grey literature search and consulted experts for additional studies.

Selection Criteria

Teams of two reviewers independently screened studies against our inclusion criteria. We included randomised control trials (RCTs) and quasi-experimental studies conducted among populations experiencing homelessness in high-income countries. Eligible interventions included permanent supportive housing (PSH), income assistance, standard case management (SCM), peer support, mental health interventions such as assertive community treatment (ACT), intensive case management (ICM), critical time intervention (CTI) and injectable antipsychotics, and substance-use interventions, including supervised consumption facilities (SCFs), managed alcohol programmes and opioid agonist therapy. Outcomes of interest were housing stability, mental health, quality of life, substance use, hospitalisations, employment and income.

Data Collection and Analysis

Teams of two reviewers extracted data in duplicate and independently. We assessed risk of bias using the Cochrane Risk of Bias tool. We performed our statistical analyses using RevMan 5.3. For dichotomous data, we used odds ratios and risk ratios with 95% confidence intervals. For continuous data, we used the mean difference (MD) with a 95% CI if the outcomes were measured in the same way between trials. We used the standardised mean difference with a 95% CI to combine trials that measured the same outcome but used different methods of measurement. Whenever possible, we pooled effect estimates using a random-effects model.

Main Results

The search resulted in 15,889 citations. We included 86 studies (128 citations) that examined the effectiveness and/or cost-effectiveness of interventions for people with lived experience of homelessness. Studies were conducted in the United States (73), Canada (8), United Kingdom (2), the Netherlands (2) and Australia (1). The studies were of low to moderate certainty, with several concerns regarding the risk of bias. PSH was found to have significant benefits on housing stability as compared to usual care. These benefits impacted both high- and moderate-needs populations with significant cimorbid mental illness and substance-use disorders. PSH may also reduce emergency department visits and days spent hospitalised. Most studies found no significant benefit of PSH on mental-health or substance-use outcomes. The effect on quality of life was also mixed and unclear. In one study, PSH resulted in lower odds of obtaining employment. The effect on income showed no significant differences. Income assistance appeared to have some benefits in improving housing stability, particularly in the form of rental subsidies. Although short-term improvement in depression and perceived stress levels were reported, no evidence of the long-term effect on mental health measures was found. No consistent impact on the outcomes of quality of life, substance use, hospitalisations, employment status, or earned income could be detected when compared with usual services. SCM interventions may have a small beneficial effect on housing stability, though results were mixed. Results for peer support interventions were also mixed, though no benefit was noted in housing stability specifically. Mental health interventions (ICM, ACT, CTI) appeared to reduce the number of days homeless and had varied effects on psychiatric symptoms, quality of life, and substance use over time. Cost analyses of PSH interventions reported mixed results. Seven studies showed that PSH interventions were associated with increased cost to payers and that the cost of the interventions were only partially offset by savings in medical- and social-services costs. Six studies revealed that PSH interventions saved the payers money. Two studies focused on the cost-effectiveness of income-assistance interventions. For each additional day housed, clients who received income assistance incurred additional costs of US$45 (95% CI, -$19, -$108) from the societal perspective. In addition, the benefits gained from temporary financial assistance were found to outweigh the costs, with a net savings of US$20,548. The economic implications of case management interventions (SCM, ICM, ACT, CTI) was highly uncertain. SCM clients were found to incur higher costs than those receiving the usual care. For ICM, all included studies suggested that the intervention may be cost-offset or cost-effective. Regarding ACT, included studies consistently revealed that ACT saved payers money and improved health outcomes than usual care. Despite having comparable costs (US$52,574 vs. US$51,749), CTI led to greater nonhomeless nights (508 vs. 450 nights) compared to usual services.

Authors' Conclusions

PSH interventions improved housing stability for people living with homelessness. High-intensity case management and income-assistance interventions may also benefit housing stability. The majority of included interventions inconsistently detected benefits for mental health, quality of life, substance use, employment and income. These results have important implications for public health, social policy, and community programme implementation. The COVID-19 pandemic has highlighted the urgent need to tackle systemic inequality and address social determinants of health. Our review provides timely evidence on PSH, income assistance, and mental health interventions as a means of improving housing stability. PSH has major cost and policy implications and this approach could play a key role in ending homelessness. Evidence-based reviews like this one can guide practice and outcome research and contribute to advancing international networks committed to solving homelessness.

Predictive factors of long-term follow-up in treatment of Korean alcoholics with naltrexone or acamprosate

Medication is integral in treating alcohol use disorder. However, because of the small to medium effect size, much effort is being exerted to identify predicting factors for effective pharmacological treatment in alcohol abuse disorder. Rather than focusing on abstinence days, alcohol craving, or frequency of drinking, which has been the focus of previous studies. Recently, there have been several studies which focused on follow-up length as an indicator of pharmacological treatment effe ctiveness. The purpose of this study was to investigate the predicting factors of long-term follow-up in treating Korean alcoholics with naltrexone or acamprosate. A retrospective study was conducted. Medical records of all patients diagnosed from November 2008 to May 2017 with alcohol abuse or alcohol dependence at psychiatric clinics at PNUYH were reviewed. We examined total days of which naltrexone or acamprosate were prescribed, and investigated if there were predicting factors maintaining follow-up at least 180 days or more. With these data, logistic regression analysis was conducted. In naltrexone long group compared to naltrexone short group, factors of having medical comorbidities [odds ratio (OR) = 5.477, P = 0.012] showed higher OR. In acamprosate long group, factors of age (OR = 1.083, P = 0.030), and use of more than four psychotropic medications (OR = 7.107, P = 0.030), showed higher OR. In both medications, predicting factors were different from the other. Further study to investigate the reasons would provide us with a new insight.

The effectiveness of substance use interventions for homeless and vulnerably housed persons: A systematic review of systematic reviews on supervised consumption facilities, managed alcohol programs, and pharmacological agents for opioid use disorder

BACKGROUND

Substance use is disproportionately high among people who are homeless or vulnerably housed. We performed a systematic overview of reviews examining the effects of selected harm reduction and pharmacological interventions on the health and social well-being of people who use substances, with a focus on homeless populations.

METHODS AND FINDINGS

We searched MEDLINE, EMBASE, PsycINFO, Joanna Briggs Institute EBP, Cochrane Database of Systematic Reviews and DARE for systematic reviews from inception to August 2019. We conducted a grey literature search and hand searched reference lists. We selected reviews that synthesized evidence on supervised consumption facilities, managed alcohol programs and pharmacological interventions for opioid use disorders. We abstracted data specific to homeless or vulnerably housed populations. We assessed certainty of the evidence using the GRADE approach. Our search identified 483 citations and 30 systematic reviews met all inclusion criteria, capturing the results from 442 primary studies. This included three reviews on supervised consumption facilities, 24 on pharmacological interventions, and three on managed alcohol programs. Supervised consumption facilities decreased lethal overdoses and other high risk behaviours without any significant harm, and improved access to care. Pharmaceutical interventions reduced mortality, morbidity, and substance use, but the impact on retention in treatment, mental illness and access to care was variable. Managed alcohol programs reduced or stabilized alcohol consumption. Few studies on managed alcohol programs reported deaths.

CONCLUSIONS

Substance use is a common chronic condition impacting homeless populations. Supervised consumption facilities reduce overdose and improve access to care, while pharmacological interventions may play a role in reducing harms and addressing other morbidity. High quality evidence on managed alcohol programs is limited.

Medication-Assisted Treatment for Opioid-Use Disorder

The United States is in the midst of a national opioid epidemic. Physicians are encouraged both to prevent and treat opioid-use disorders (OUDs). Although there are 3 Food and Drug Administration-approved medications to treat OUD (methadone, buprenorphine, and naltrexone) and there is ample evidence of their efficacy, they are not used as often as they should. We provide a brief review of the 3 primary medications used in the treatment of OUD. Using data from available medical literature, we synthesize existing knowledge and provide a framework for how to determine the optimal approach for outpatient management of OUD with medication-assisted treatments.

Pharmacological Treatment of Youth Substance Use Disorders

While the majority of youth who experiment with alcohol and drugs do not develop problematic levels of use, 5% of adolescents and 15% of young adults meet criteria for a substance use disorder (SUD). Pharmacotherapy, in combination with behavioral interventions, has the potential to increase the likelihood of successful treatment for youth struggling with SUD; however, the literature in this area is limited. To date, there are no Food and Drug Administration (FDA)-approved medications for adolescent SUD, other than buprenorphine, which has been approved down to 16 years of age for opioid use disorder. Despite alcohol and cannabis being the most commonly used substances during adolescence, only three medications have been tested among this demographic, and only two have warranted further study (i.e., naltrexone for alcohol and N-acetylcysteine for cannabis use disorder). Although less common in adolescents and young adults, the most promising pharmacological findings for this age group are for opioid (buprenorphine) and tobacco (bupropion and varenicline) use disorders. In addition, despite the recent marked increases in electronic nicotine delivery systems (i.e., vaping) among youth, treatment strategies are still in their infancy and no recommendation exists for how to promote cessation for youth vaping. Current findings are limited by: small, demographically homogeneous samples; few trials, including a substantial number of youth younger than 18; low retention; medication adherence rates; and minimal information on effective dosing levels and long-term outcomes. Overall, pharmacotherapy may be a potentially effective strategy to increase treatment effects; however, more rigorous research trials are warranted before FDA approval would be granted for any of the potential adjunctive medications in this age group.

Cost-Effectiveness Analysis of Genotype-Guided Treatment Allocation in Patients with Alcohol Use Disorders Using Naltrexone or Acamprosate, Using a Modeling Approach

Alcohol use disorders (AUD) are a major contributor to the global burden of disease, and have huge societal impact. Some studies show that AUD patients carrying the G-allele of the OPRM1 variant c.118A>G respond better to naltrexone, resulting in reduced relapse rates compared to carriers of the AA genotype. Genotype-guided treatment allocation of these patients carrying a G-allele to naltrexone could potentially improve the treatment outcome. However, cost-effectiveness of this strategy should be investigated before considering clinical implementation. We, therefore, evaluated costs and Quality-Adjusted Life-Years (QALYs), using a modelling approach, from an European perspective, of genotype-guided treatment allocation (G-allele carriers receiving naltrexone; AA homozygotes acamprosate or naltrexone) compared to standard care (random treatment allocation to acamprosate or naltrexone), by using a Markov model. Genotype-guided treatment allocation resulted in incremental costs of EUR 66 (95% CI -28 to 149) and incremental effects of 0.005 QALYs (95% CI 0.000-0.011) per patient (incremental cost-effectiveness ratio of EUR 13,350 per QALY). Sensitivity analyses showed that the risk ratio to relapse after treatment allocation had the largest impact on the cost-effectiveness. Depending on the willingness to pay for a gain of one QALY, probabilities that the intervention is cost-effective varies between 6 and 79%. In conclusion, pharmacogenetic treatment allocation of AUD patients to naltrexone, based on OPRM1 genotype, can be a cost-effective strategy, and could have potential individual and societal benefits. However, more evidence on the impact of genotype-guided treatment allocation on relapse is needed to substantiate these conclusions, as there is contradictory evidence about the effectiveness of OPRM1 genotyping.

The safety of pharmacologic treatment for pediatric obesity

INTRODUCTION

Pediatric obesity is a serious public health concern. Five medications have been approved by the Food and Drug Administration (FDA) for chronic weight management in adults with obesity, when used as an adjunct to lifestyle modification. Orlistat is the only FDA-approved medication for pediatric patients aged 12 years and above.

AREAS COVERED

This paper summarizes safety and efficacy data from clinical trials of weight loss medications conducted among pediatric samples. Relevant studies were identified through searches in PubMed.

EXPERT OPINION

Orlistat, as an adjunct to lifestyle modification, results in modest weight losses and may be beneficial for some pediatric patients with obesity. However, gastrointestinal side effects are common and may limit use. In adults taking orlistat, rare but severe adverse events, including liver and renal events, have been reported. Recent pediatric pharmacokinetic studies of liraglutide have demonstrated similar safety and tolerability profiles as found in adults, with gastrointestinal disorders being the most common adverse events. Clinical trials are needed of liraglutide, as well as other medications for obesity, that systematically evaluate their risks and benefits in pediatric patients.

Predictors for retention in treatment with a UK community-based naltrexone programme for opioid dependence

Aims and method

To evaluate the efficacy of naltrexone maintenance therapy in a community-based programme for opioid-dependent patients and to identify predictors for longer-term retention in treatment. A retrospective case-note study was conducted in 142 people dependent on opioids who had undergone detoxification and maintained adherence to naltrexone treatment for a minimum of 4 weeks. Social and clinical demographic factors during treatment were recorded using a standardised naltrexone monitoring scale. Efficacy was measured as retention in treatment, and potential predictors were examined using regression analysis.

Results

Although there was overall low retention of patients in treatment, 55.6% of the patients remained in treatment for 4–8 weeks, and 29.6% of the patients remained in treatment for 17 weeks or more. Enhanced long-term retention in treatment was associated with Asian or other minority ethnic status, employment, parental supervision of naltrexone administration, less boredom, short duration of addiction, younger age, low alcohol intake and no cannabis use in univariate analyses. Short duration of opioid dependence syndrome (3 years) and low alcohol intake (<10 units/week) were significant independent predictors for longer-term retention in treatment in subsequent multivariate analysis.

Clinical implications

Low alcohol intake and shorter duration of addiction were significant independent predictors for longer-term retention in treatment, but retention rates for naltrexone remain low overall. Additional psychosocial support may be needed to address these issues.

Treatment options for alcoholic and non-alcoholic fatty liver disease: A review

Alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) are serious health problems worldwide. These two diseases have similar pathological spectra, ranging from simple steatosis to hepatitis to cirrhosis and hepatocellular carcinoma. Although most people with excessive alcohol or calorie intake display abnormal fat accumulation in the liver (simple steatosis), a small percentage develops progressive liver disease. Despite extensive research on understanding the pathophysiology of both these diseases there are still no targeted therapies available. The treatment for ALD remains as it was 50 years ago: abstinence, nutritional support and corticosteroids (or pentoxifylline as an alternative if steroids are contraindicated). As for NAFLD, the treatment modality is mainly directed toward weight loss and co-morbidity management. Therefore, new pathophysiology directed therapies are urgently needed. However, the involvement of several inter-related pathways in the pathogenesis of these diseases suggests that a single therapeutic agent is unlikely to be an effective treatment strategy. Hence, a combination therapy towards multiple targets would eventually be required. In this review, we delineate the treatment options in ALD and NAFLD, including various new targeted therapies that are currently under investigation. We hope that soon we will be having an effective multi-therapeutic regimen for each disease.

Crystal structure of naltrexone chloride solvates with ethanol, propan-2-ol, and 2-methyl-propan-2-ol

Naltrexone [systematic name: 17-(cyclo-propyl-meth-yl)-3,14-di-hydroxy-4,5α-epoxymorphinan-6-one] is an opioid receptor competitive antagonist that has been widely used to prevent relapse in opioid- and alcohol-dependent subjects. Its chloride salt forms non-isomorphic solvates with ethanol (C20H24NO4+·Cl-·C2H5OH) (I), propan-2-ol (C20H24NO4+·Cl-·C3H7OH) (II), and 2-methyl-propan-2-ol (C20H24NO4+·Cl-·C4H9OH) (III). The naltrexone cation can be described as a T-shape made out of two ring systems, a tetra-hydro-2H-naphtho-[1,8-bc]furan system and a deca-hydro-isoquinolinium subunit, that are nearly perpendicular to one another. The flexible cyclo-propyl-methyl group can adopt various different conformations in response to its surroundings: an increase of available space around cyclo-propyl-methyl group may allow it to adopt a more favorable conformation. In all these structures, the alcohol mol-ecules occupy infinite solvent-filled channels. All three compounds described are attractive crystalline forms for unambiguous identification of naltrexone chloride after isolation from a pharmaceutical form. Compound (III) was refined as a two-component twin.

Extended-release naltrexone reduces alcohol consumption among released prisoners with HIV disease as they transition to the community

BACKGROUND

Alcohol use disorders (AUDs) are highly prevalent among persons living with HIV (PLH) within the criminal justice system (CJS). Extended-release naltrexone (XR-NTX) has not been previously evaluated among CJS-involved PLH with AUDs.

METHODS

A randomized, double-blind, placebo-controlled trial was conducted among 100 HIV+ prisoners with AUDs. Participants were randomized 2:1 to receive 6 monthly injections of XR-NTX or placebo starting one week prior to release. Using multiple imputation strategies for data missing completely at random, data were analyzed for the 6-month post-incarceration period. Main outcomes included: time to first heavy drinking day; number of standardized drinks/drinking day; percent of heavy drinking days; pre- to post-incarceration change in average drinks/day; total number of drinking days; and a composite alcohol improvement score comprised of all 5 parameters.

RESULTS

There was no statistically significant difference overall between treatment arms for time-to-heavy-drinking day. However, participants aged 20-29 years who received XR-NTX had a longer time to first heavy drinking day compared to the placebo group (24.1 vs. 9.5days; p<0.001). There were no statistically significant differences between groups for other individual drinking outcomes. A sub-analysis, however, found participants who received ≥4 XR-NTX were more likely (p<0.005) to have improved composite alcohol scores than the placebo group. Post-hoc power analysis revealed that despite the study being powered for HIV outcomes, sufficient power (0.94) was available to distinguish the observed differences.

CONCLUSIONS

Among CJS-involved PLH with AUDs transitioning to the community, XR-NTX lengthens the time to heavy drinking day for younger persons; reduces alcohol consumption when using a composite alcohol consumption score; and is not associated with any serious adverse events.

Review article: pharmacotherapy for alcohol dependence - the why, the what and the wherefore

BACKGROUND

The development of alcohol dependence is associated with significant morbidity and mortality. For the majority of affected people the most appropriate goal, in terms of drinking behaviour, is abstinence from alcohol. Psychosocial intervention is the mainstay of the treatment but adjuvant pharmacotherapy is also available and its use recommended.

AIM

To provide an updated analysis of current and potential pharmacotherapeutic options for the management of alcohol dependence. In addition, factors predictive of therapeutic outcome, including compliance and pharmacogenetics, and the current barriers to treatment, including doctors' unwillingness to prescribe these agents, will be explored.

METHODS

Relevant papers were selected for review following extensive, language- and date-unrestricted, electronic and manual searches of the literature.

RESULTS

Acamprosate and naltrexone have a substantial evidence base for overall efficacy, safety and cost-effectiveness while the risks associated with the use of disulfiram are well-known and can be minimised with appropriate patient selection and supervision. Acamprosate can be used safely in patients with liver disease and in those with comorbid mental health issues and co-occurring drug-related problems. A number of other agents are being investigated for potential use for this indication including: baclofen, topiramate and metadoxine.

CONCLUSION

Pharmacotherapy for alcohol dependence has been shown to be moderately efficacious with few safety concerns, but it is substantially underutilised. Concerted efforts must be made to remove the barriers to treatment in order to optimise the management of people with this condition.

Ethical and clinical safety considerations in the design of an effectiveness trial: A comparison of buprenorphine versus naltrexone treatment for opioid dependence

We examine ethical challenges encountered in the design of an effectiveness trial (CTN-0051; X:BOT), comparing sublingual buprenorphine-naloxone (BUP-NX), an established treatment for opioid dependence, to the newer extended-release injectable naltrexone (XR-NTX). Ethical issues surrounded: 1) known poor effectiveness of one possible, commonly used treatment as usual control condition-detoxification followed by counseling without medication; 2) the role of patients' preferences for treatments, given that treatments were clinically approved and available to the population; 3) differences between the optimal "usual treatment" clinical settings for different treatments making it challenging to design a fair comparison; 4) vested interest groups favoring different treatments exerting potential influence on the design process; 5) potentially vulnerable populations of substance users and prisoners; 6) potential therapeutic misconception in the implementation of safety procedures; and 7) high cost of a large trial limiting questions that could be addressed. We examine how the design features underlying these ethical issues are characteristic of effectiveness trials, which are often large trials that compare treatments with varying degrees of existing effectiveness data and familiarity to patients and clinicians, in community-based treatment settings, with minimal exclusion criteria that could involve vulnerable populations. Hence, investigators designing effectiveness trials may wish to remain alert to the possibility of similar ethical issues.

The Role of Pharmacotherapy in the Treatment of Adolescent Substance Use Disorders

Adolescent substance use disorders (SUDs) are a significant public health issue due to the associated morbidity, mortality, and societal cost. While effective for some adolescents, psychosocial interventions generally produce small-to-moderate reductions in substance use. Most youth relapse within 12 months of treatment. One approach to improve outcomes is through adjunctive pharmacotherapy. Medication assisted treatments have been shown to improve adult SUD treatment outcomes, and preliminary studies in adolescents suggest that combining medication with psychosocial interventions may also enhance SUD outcomes for youth. This article presents a comprehensive review and grading of the evidence from studies conducted in adolescents with SUDs.

A Perspective on Opioid Pharmacotherapy: Where We Are and How We Got Here

Four decades of concerted pharmacotherapy research has netted us three medications approved for the treatment of opioid addiction. The clinical pharmacology, safety, efficacy, and clinical use of these medications are familiar to most clinical researchers and clinicians in addiction medicine. Less common is an understanding of the social and political forces behind the choice of these particular agents for their development and how these forces continue to influence how clinicians interact with patients who have opioid use disorder. This review brings into focus those forces and puts into context how we came to have these particular medications. What we know determines our views of the world we live in, including our patients and ourselves, as well as those to whom we give power to govern us. The issues are raised by the author, who does not provide resolutions; answers to the questions of how to address the issues must come from the reader.

Alcoholic liver disease: Treatment

The excess consumption of alcohol is associated with alcoholic liver diseases (ALD). ALD is a major healthcare problem, personal and social burden, and significant reason for economic loss worldwide. The ALD spectrum includes alcoholic fatty liver, alcoholic hepatitis, cirrhosis, and the development of hepatocellular carcinoma. The diagnosis of ALD is based on a combination of clinical features, including a history of significant alcohol intake, evidence of liver disease, and laboratory findings. Abstinence is the most important treatment for ALD and the treatment plan varies according to the stage of the disease. Various treatments including abstinence, nutritional therapy, pharmacological therapy, psychotherapy, and surgery are currently available. For severe alcoholic hepatitis, corticosteroid or pentoxifylline are recommended based on the guidelines. In addition, new therapeutic targets are being under investigation.

Potent inhibition of alcohol self-administration in alcohol-preferring rats by a κ-opioid receptor antagonist

A substituted aryl amide derivative of 6-naltrexamine--17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-[(4'-trimethylfluoro)benzamido]morphinan-hydrochloride--(compound 5), previously shown to be a potent κ-opioid receptor antagonist, was used to characterize the physicochemical properties and efficacy to decrease alcohol self-administration in alcohol-preferring rats (P-rats) and binge-like P-rats. Previous studies showed that compounds closely related to compound 5 possessed favorable properties regarding penetration of the blood-brain barrier. Pharmacokinetic studies showed that compound 5 had acceptable bioavailability. In contrast to other κ-receptor antagonists, in particular norbinaltorphimine, compound 5 showed favorable drug-like properties. Based on these findings, further studies were done. Safety studies showed that compound 5 was not hepatotoxic at doses 200-fold greater than an efficacious dose. The effects of compound 5 or naltrexone on the hepatotoxicity of thiobenzamide were investigated. In contrast to naltrexone, which exacerbated thiobenzamide-mediated hepatotoxicity, compound 5 was observed to be hepatoprotective. Based on the physicochemical properties of compound 5, the compound was examined in rat animal models of alcohol self-administration. The inhibition of ethanol self-administration by compound 5 in alcohol-dependent and alcohol-nondependent P-rats trained to self-administer a 10% (w/v) ethanol solution, using operant techniques, showed very potent efficacy (i.e., estimated ED50 values of 4-5 μg/kg). In a binge-like P-rat animal model, inhibition of alcohol self-administration by compound 5 had an estimated ED50 value of 8 μg/kg. The results suggest that compound 5 is a potent drug-like κ-opioid receptor antagonist of utility in alcohol cessation medications development.

Naltrexone (50 mg) plus psychotherapy in alcohol-dependent patients: a meta-analysis of randomized controlled trials

BACKGROUND

Alcoholism is a chronic and potentially fatal disease. One of the therapeutic options is pharmacotherapy with the opioid antagonist naltrexone in combination with psychotherapy.

OBJECTIVES

The objective of this review was to compare the clinical effectiveness of naltrexone (50 mg/day) versus that of a placebo in alcohol-dependent patients receiving psychotherapy.

METHODS

The clinical effectiveness of the treatment was assessed in accordance with the principles of systematic review, as outlined in the Cochrane Collaboration guidelines (Cochrane Reviewer's Handbook) and the guidelines of the Polish Agency for Health Technology Assessment (AHTAPol).

RESULTS

Statistical significances in favor of the treatment modality were found in both the percentage of patients maintaining total abstinence and the percentage of relapsed patients.

CONCLUSION

The analysis herein demonstrates that for short (12-16 weeks) period of treatment, a combination of naltrexone administration and psychotherapy results in high clinical efficacy with a safety profile comparable to that of the placebo in the treatment of alcohol-dependent patients. The side effects of naltrexone treatment are usually mild and transient.

Maintenance of reinforcement to address the chronic nature of drug addiction

BACKGROUND

Drug addiction can be a chronic problem. Abstinence reinforcement can initiate drug abstinence, but as with other treatments many patients relapse after the intervention ends. Abstinence reinforcement can be maintained to promote long-term drug abstinence, but practical means of implementing long-term abstinence reinforcement are needed.

METHODS

We reviewed 8 clinical trials conducted in Baltimore, MD from 1996 through 2010 that evaluated the therapeutic workplace as a vehicle for maintaining reinforcement for the treatment of drug addiction. The therapeutic workplace uses employment-based reinforcement in which employees must provide objective evidence of drug abstinence or medication adherence to work and earn wages.

RESULTS

Employment-based reinforcement can initiate (3 of 4 studies) and maintain (2 studies) cocaine abstinence in methadone patients, although relapse can occur even after long-term exposure to abstinence reinforcement (1 study). Employment-based reinforcement can also promote abstinence from alcohol in homeless alcohol dependent adults (1 study), and maintain adherence to extended-release naltrexone in opioid dependent adults (2 studies).

CONCLUSION

Treatments should seek to promote life-long effects in patients. Therapeutic reinforcement may need to be maintained indefinitely to prevent relapse. Workplaces could be effective vehicles for the maintenance of therapeutic reinforcement contingencies for drug abstinence and adherence to addiction medications.

Agonist treatment in opioid use: advances and controversy

Opioid dependence is a chronic relapsing condition which requires comprehensive care; pharmacological agents form the mainstay of its long term treatment. The two most popular approaches are the harm reduction method using agonists and the complete abstinence method using antagonists. Currently, particularly from the harm minimization perspective and the low feasibility of an abstinence based approach, there is an increasing trend toward agonist treatment. The use of buprenorphine has gained popularity in view of its safety profile and the availability of the buprenorphine-naloxone combination has made it popular as a take-home treatment. This review outlines the pharmacological advances and controversies in this area.

Design and synthesis of a bivalent ligand to explore the putative heterodimerization of the mu opioid receptor and the chemokine receptor CCR5

The bivalent ligand approach has been utilized not only to study the underlying mechanism of G protein-coupled receptors dimerization and/or oligomerization, but also to enhance ligand affinity and/or selectivity for potential treatment of a variety of diseases by targeting this process. Substance abuse and addiction have made both the prevention and the treatment of human immunodeficiency virus (HIV) infection more difficult to tackle. Morphine, a mu opioid receptor (MOR) agonist, can accelerate HIV infection through up-regulating the expression of the chemokine receptor CCR5, a well-known co-receptor for HIV invasion to the host cells and this has been extensively studied. Meanwhile, two research groups have described the putative MOR-CCR5 heterodimers in their independent studies. The purpose of this paper is to report the design and synthesis of a bivalent ligand to explore the biological and pharmacological process of the putative MOR-CCR5 dimerization phenomenon. The developed bivalent ligand thus contains two distinct pharmacophores linked through a spacer; ideally one of which will interact with the MOR and the other with the CCR5. Naltrexone and Maraviroc were selected as the pharmacophores to generate such a bivalent probe. The overall reaction route to prepare this bivalent ligand was convergent and efficient, and involved sixteen steps with moderate to good yields. The preliminary biological characterization showed that the bivalent compound 1 retained the pharmacological characteristics of both pharmacophores towards the MOR and the CCR5 respectively with relatively lower binding affinity, which tentatively validated our original molecular design.

Structure selectivity relationship studies of 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-[(4'-pyridyl)carboxamido]morphinan derivatives toward the development of the mu opioid receptor antagonists

Mu opioid receptor antagonists have been applied to target a variety of diseases clinically. The current study is designed to explore the structure selectivity relationship (SSR) of 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-[(4'-pyridyl)carboxamido]morphinan (NAP), a lead compound identified as a selective mu opioid receptor antagonist based on the previous study. Among a series of NAP derivatives synthesized, compounds 6 (NMP) and 9 (NGP) maintained comparable binding affinity, selectivity and efficacy to the lead compound. Particularly, the mu opioid receptor selectivity over kappa opioid receptor of NGP was considerably enhanced compared to that of NAP. Overall, the preliminary SSR supported our original hypothesis that an alternate 'address' domain may exist in the mu opioid receptor, which favors the ligands carrying a hydrogen bond acceptor and an aromatic system to selectively recognize the mu opioid receptor.

Opioid antagonists for alcohol dependence

BACKGROUND

Alcohol dependence belongs to the globally leading health risk factors. Therapeutic success of psychosocial programs for relapse prevention is moderate and could be increased by an adjuvant treatment with the opioid antagonists naltrexone and nalmefene.

OBJECTIVES

To determine the effectiveness and tolerability of opioid antagonists in the treatment of alcohol dependence.

SEARCH STRATEGY

We searched the Cochrane Drugs and Alcohol Group (CDAG) Specialized Register, PubMed, EMBASE and CINAHL in January 2010 and inquired manufacturers and researchers for unpublished trials.

SELECTION CRITERIA

All double-blind randomised controlled trials (RCTs) which compare the effects of naltrexone or nalmefene with placebo or active control on drinking-related outcomes.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted outcome data. Trial quality was assessed by one author and cross-checked by a second author.

MAIN RESULTS

Based on a total of 50 RCTs with 7793 patients, naltrexone reduced the risk of heavy drinking to 83% of the risk in the placebo group RR 0.83 (95% CI 0.76 to 0.90) and decreased drinking days by about 4%, MD -3.89 (95% CI -5.75 to -2.04). Significant effects were also demonstrated for the secondary outcomes of the review including heavy drinking days, MD - 3.25 (95% CI -5.51 to -0.99), consumed amount of alcohol, MD - 10.83 (95% CI -19.69 to -1.97) and gamma-glutamyltransferase, MD - 10.37 (95% CI -18.99 to -1.75), while effects on return to any drinking, RR 0.96 (95 CI 0.92 to 1.00) missed statistical significance. Side effects of naltrexone were mainly gastrointestinal problems (e.g. nausea: RD 0.10; 95% CI 0.07 to 0.13) and sedative effects (e.g. daytime sleepiness: RD 0.09; 95% CI 0.05 to 0.14). Based on a limited study sample, effects of injectable naltrexone and nalmefene missed statistical significance. Effects of industry-sponsored studies, RR 0.90 (95% CI 0.78 to 1.05) did not significantly differ from those of non-profit funded trials, RR 0.84 (95% CI 0.77 to 0.91) and the linear regression test did not indicate publication bias (P = 0.765).

AUTHORS' CONCLUSIONS

Naltrexone appears to be an effective and safe strategy in alcoholism treatment. Even though the sizes of treatment effects might appear moderate in their magnitudes, these should be valued against the background of the relapsing nature of alcoholism and the limited therapeutic options currently available for its treatment.

Synthesis and pharmacological evaluation of 6-naltrexamine analogs for alcohol cessation

A series of substituted aryl amide derivatives of 6-naltrexamine, 3 designed to be metabolically stable were synthesized and used to characterize the structural requirements for their potency to binding and functional activity of human mu (mu), delta (delta) and kappa (kappa) opioid and nociceptin (NOP) receptors. Binding assays showed that 4-10 had subnanomolar K(i) values for mu and kappa opioid receptors. Functional assays for stimulation of [(35)S]GTPgammaS binding showed that several compounds acted as partial or inverse agonists and antagonists of the mu and delta, kappa opioid or NOP receptors. The compounds showed considerable stability in the presence of rat, mouse or human liver preparations and NADPH. The inhibitory activity on the functional activity of human cytochrome P450s was examined to determine any potential inhibition by 4-9. Only modest inhibition of CYP3A4, CYP2C9 and CYP2C19 was observed for a few of the analogs. As a representative example, radiolabeled 6 was examined in vivo and showed reasonable brain penetration. The inhibition of ethanol self-administration in rats trained to self-administer a 10% (w/v) ethanol solution, utilizing operant techniques showed 5-8 to have very potent efficacy (ED(50) values 19-50 microg/kg).

Predicting the effect of naltrexone and acamprosate in alcohol-dependent patients using genetic indicators

Acamprosate and naltrexone are effective medications in the treatment of alcoholism. However, effect sizes are modest. Pharmacogenomics may improve patient-treatment-matching and effect sizes. It is hypothesized that naltrexone exerts its effect through genetic characteristics associated with the dopaminergic/opioidergic positive reinforcement system, whereas acamprosate works through the glutamatergic/GABAergic negative reinforcement system. Alcohol-dependent subjects were randomly assigned to either acamprosate or naltrexone. Subjects participated in a cue-exposure experiment at the day before and at the last day of medication. Reductions in cue-induced craving and physiological cue reactivity were measured. Differential effects of naltrexone and acamprosate on these outcomes were tested for different polymorphisms of the opioid, dopamine, glutamate and GABA-receptors. Significant matching effects were found for polymorphisms at the DRD2, GABRA6 and GABRB2 gene. In addition, a trend was found for the OPRM1 polymorphism. This provides evidence for the matching potential of genotypes. It is expected that more effective treatments can be offered when genetic information is used in patient-treatment-matching.

Chronic ethanol intake-induced changes in open-field behavior and calcium/calmodulin-dependent protein kinase IV expression in nucleus accumbens of rats: naloxone reversal

AIM

To investigate the effects of chronic ethanol intake on the locomotor activity and the levels of calcium/calmodulin-dependent protein kinase IV (CaM kinase IV) in the nucleus accumbens (NAc) of rats. Simultaneously, the effects of nonselective opioid antagonist (naloxone) on the CaM kinase IV expression in the NAc and ethanol consumption of rats were also observed.

METHODS

Ethanol was administered in drinking water at the concentrations of 6% (v/v), for 28 d. The locomotor activity of rats was investigated in the open-field apparatus. CaM kinase IV levels in the NAc were analyzed using Western blotting.

RESULTS

Rats consuming ethanol solution exhibited a significant decrease of ambulation activity, accompanied by a reduced frequency of explorative rearing in an open-field task on d 7 and d 14 of chronic ethanol ingestion, whereas presumed adaptation to the neurological effects of ethanol was observed on d 28. Chronic ethanol intake elicited a significant decrease of the CaM kinase IV expression in the nuclei, but not in the cytoplasm of the NAc on d 28. Naloxone treatment significantly attenuated ethanol intake of rats and antagonized the decrease of CaM kinase IV in the nuclei of NAc neurons. The cytosolic CaM kinase IV protein levels of the NAc also increased in rats exposed to ethanol plus naloxone.

CONCLUSION

Chronic ethanol intake-induced changes in explorative behavior is mediated at least partly by changes in CaM kinase IV signaling in the nuclei of the NAc, and naloxone attenuates ethanol consumption through antagonizing the downregulation of CaM kinase IV in the NAc.

A microdialysis study of extracellular levels of acamprosate and naltrexone in the rat brain following acute and repeated administration

Acamprosate and naltrexone are widely used in the treatment of alcoholism. However, numerous studies in rodents have shown differential effects of these compounds on alcohol consumption and/or relapse-like behavior following acute versus repeated administration. In order to determine if these differential behavioral effects could be attributable to changes in extracellular levels of these compounds, we used in vivo microdialysis to monitor extracellular levels of acamprosate and naltrexone in the rat medial prefrontal cortex following acute and repeated intraperitoneal administration. For acute treatment, animals received a single administration of acamprosate (100 or 300 mg/kg) or naltrexone (1 or 3 mg/kg). For repeated treatment, animals received once daily treatment with saline, acamprosate (300 mg/kg) or naltrexone (3 mg/kg) for 10 days before a subsequent challenge with the compound according to their respective pretreatment group. Dialysate levels of acamprosate and naltrexone were analyzed by liquid chromatography-tandem mass spectrometry and high performance liquid chromatography, respectively. Following acute administration, peak dialysate concentrations of each compound were dose-dependent, observed within 1 hour of administration, and were found to be in the low micromolar range for acamprosate and in the low to mid-nanomolar range for naltrexone. Pretreatment with acamprosate, but not naltrexone, for 10 days resulted in higher dialysate concentrations of the compound relative to saline-pretreated controls. Thus, repeated administration of acamprosate, but not naltrexone, results in augmented extracellular levels of the compound in the brain relative to saline-pretreated controls, which may explain the need for repeated administration of acamprosate in order to observe effects on alcohol consumption and/or relapse.

Synthesis and biological evaluation of alpha- and beta-6-amido derivatives of 17-cyclopropylmethyl-3, 14beta-dihydroxy-4, 5alpha-epoxymorphinan: potential alcohol-cessation agents

Substituted aryl and aliphatic amide analogues of 6-naltrexamine were synthesized and used to characterize the binding to and functional activity of human mu-, delta-, and kappa-opioid receptors. Competition binding assays showed 11-25 and 27-31 bound to the mu (K(i) = 0.05-1.2 nM) and kappa (K(i) = 0.06-2.4 nM) opioid receptors. Compounds 11-18 possessed significant binding affinity for the delta receptor (K(i) = 0.8-12.4 nM). Functional assays showed several compounds acted as partial or full agonists of delta or kappa receptors while retaining an antagonist profile at the mu receptor. Structure-activity relationship for aryl amides showed that potent compounds possessed lipophilic groups or substituents capable of hydrogen bonding. Metabolic stability studies showed that 11, 12, and 14 possessed considerable stability in the presence of rat, mouse, or human liver preparations. The ED 50 of inhibition of 10% ethanol self-administration in trained rats, using operant techniques for 11, was 0.5 mg/kg.

Hepatic safety of once-monthly injectable extended-release naltrexone administered to actively drinking alcoholics

BACKGROUND

Hepatoxicity has been reported with oral naltrexone. Hepatic safety data were examined from a 6-month study evaluating the efficacy and safety of a now available extended-release formulation of naltrexone (XR-NTX) in patients with alcohol dependence.

METHODS

In all, 624 patients (68% male; median age of 44 years) were randomly assigned to XR-NTX 380 mg (n = 205), XR-NTX 190 mg (n = 210), or placebo (n = 209).

RESULTS

There were no significant differences in alanine aminotransferase, aspartate aminotransferase, or bilirubin levels between the study groups at study initiation or at subsequent assessments. Gamma-glutamyltransferase in the XR-NTX 380 mg group was lower compared with placebo at weeks 4, 8, 12, and 20. Both high (>3 times the upper limit of normal) liver chemistry tests (LCTs) and hepatic-related adverse events were infrequent in all study groups. In patients who were drinking heavily throughout the study, obese subjects, or those taking nonsteroidal anti-inflammatory drugs, there was no increase in frequency of high LCTs or hepatic-related adverse events in patients receiving XR-NTX (either dose) compared with placebo.

CONCLUSION

Extended-release formulation of naltrexone does not appear to be hepatotoxic when taken at the recommended clinical doses in actively drinking alcohol-dependent patients.

Herbal mixtures consisting of puerarin and either polyenylphosphatidylcholine or curcumin provide comprehensive protection against alcohol-related disorders in P rats receiving free choice water and 15% ethanol in pure water

Chronic alcohol drinking has been associated with the development of a number of abnormalities, including neuron-behavioral disorders, liver, pancreas, and heart-related diseases and inflammation and immune disorders. Because diverse mechanisms are involved in the development of these disorders, the commonly used receptor- or enzyme-specific drugs do not provide comprehensive protection against the adverse effects of alcoholism. This study describes possible therapeutic potency of puerarin (PU) from kudzu root, polyenylphosphatidylcholine from soy (SPCh), and curcumin (CU) from turmeric against alcohol's addiction-related and inflammatory-related abnormalities in alcohol-preferring P rats receiving free choice water and 15% ethanol in water. P-rats were fed once daily either the vehicle (for control) or different doses of PU, SPCh, CU, PU + SPCh, or PU + CU. The rats were divided in two groups: one received water alone, and the other free choice water and ethanol. Four rats from each group were fitted with electroencephalogram (EEG) electrodes for EEG recording. After 70 days of alcohol drinking, alcohol was withdrawn for 2 weeks, and the withdrawal symptoms were assessed. This study showed that alcohol drinking for 70 days (1) caused liver inflammation characterized by elevated tumor necrosis factor-alpha, interleukin-1beta, and matrix metalloproteinase-9 expression and (2) dysregulated lipopolysaccharide (LPS)-induced pleurisy. Alcohol withdrawal after 70 days of drinking generated severe withdrawal symptoms including seizure-type EEG activity. PU suppressed the addiction-mediated abnormalities but did not affect the inflammation-related abnormalities, while SPCh or CU suppressed only the inflammation-related abnormalities in alcohol-drinking rats subjected to LPS-induced pleurisy. A combination of PU with SPCh or CU suppressed both the addiction-related and inflammation-related abnormalities of alcohol drinking. Therefore, a mixture consisting of PU and either SPCh or CU may provide alternative therapy for alcohol-related disorders.

Structural characterization of anhydrous naloxone‐ and naltrexone hydrochloride by high resolution laboratory X‐ray powder diffraction and thermal analysis

The crystal structures of the analgesic compounds anhydrous naloxone and naltrexone hydrochloride were determined ab initio from high resolution laboratory X-ray powder diffraction data. Both compounds crystallize in the orthorhombic space group P2(1)2(1)2(1) with lattice parameters of a = 14.6588(10) A, b = 17.4363(9) A, c = 7.96200(22) A, and V = 2035.06(23) A(3) for naloxone hydrochloride and a = 15.4560(5) A, b = 14.9809(4) A, c = 7.84121(18) A, and V = 1815.58(11) A(3) for naltrexone hydrochloride. The crystal structure of anhydrous naloxone hydrochloride forms one-dimensional chains through hydrogen bonds. In the crystal structure of anhydrous naltrexone hydrochloride, two-dimensional sheets are formed by hydrogen bonds. The dehydration processes of naloxone hydrochloride dehydrate and naltrexone hydrochloride tetrahydrate was analyzed by DTA, DSC, TG, and MG.

Long-acting injectable naltrexone for the treatment of alcohol dependence

Combining pharmacotherapy with psychosocial and behavioral interventions has helped improve the treatment of alcohol dependence. However, the clinical use of effective medications, such as naltrexone, is limited by poor adherence to a daily oral regimen. Recently, a once monthly extended-release injectable formulation of naltrexone (Vivitrol, Alkermes, Inc.) became the first FDA-approved long-acting formulation of naltrexone for alcohol dependence. Compared with the oral preparation, extended-release naltrexone shows reduced peaks and minimal fluctuations in plasma levels that may possibly lead to a more benign adverse-event profile. The administration of long-acting naltrexone in conjunction with psychosocial support has been associated with significant improvement in drinking outcome measures, especially among patients who are abstinent entering treatment. Additional studies are warranted to increase the knowledge on the clinical applications of long-acting naltrexone in other addictive disorders and to compare extended-release naltrexone with other long-acting formulations that are in development. The clinical availability of extended-release naltrexone has the potential to enhance treatment outcomes for alcohol and other drug dependence disorders.

Naltrexone effect on physiological and subjective response to a cold pressor task

In this double-blind, cross-over study physiological (i.e. blood pressure, heart rate, plasma catecholamine concentrations, plasma cortisol concentrations) and subjective (i.e. McGill Pain Questionnaire, positive affect, distress) response to a cold pressor task was assessed in 19 subjects 1 h after the administration of 50 mg naltrexone and after placebo. Significant differences in plasma catecholamine concentrations were found. Plasma epinephrine concentrations increased during the 1 h period after naltrexone administration but remained largely unchanged after placebo administration. A significant treatment x period effect was also found for plasma norepinephrine concentrations. No significant differences were found for other measures assessed. Further research is necessary to determine the subpopulations in which these effects are of greatest magnitude and the long term safety implications of these effects.

The effect of naltrexone and acamprosate on cue-induced craving, autonomic nervous system and neuroendocrine reactions to alcohol-related cues in alcoholics

INTRODUCTION

Acamprosate and naltrexone have been shown to be effective in relapse prevention of alcoholism. It is hypothesized that naltrexone exerts its effects primarily on cue-induced craving and neuroendocrine cue reactivity, whereas acamprosate exerts its effect primarily on autonomic nervous system reactions to alcohol-related cues.

EXPERIMENTAL PROCEDURES

In a randomized double-blind experiment, 131 abstinent alcoholics received either acamprosate (n=56), naltrexone (n=52) or placebo (n=23) for three weeks and participated in two cue-exposure sessions: the first the day before and the second at the last day of medication.

RESULTS

Consistent with the hypotheses, naltrexone reduced craving more than acamprosate, and acamprosate reduced heart rate more than naltrexone. No medication effect was found on cue-induced cortisol.

DISCUSSION

The findings provide some evidence for differential effects of naltrexone and acamprosate: naltrexone may exert its effect, at least partly, by the reduction of cue-induced craving, whereas acamprosate may exert its effect, at least partly, by the reduction of autonomic nervous system reactions to alcohol-related cues.

Does naltrexone affect craving in abstinent opioid-dependent patients?

Naltrexone blocks the opioid receptors that modulate the release of dopamine in the brain reward system and therefore blocks the rewarding effects of heroin and alcohol. It is generally assumed that naltrexone leads to reduction of craving, but few studies have been performed to prove this. The purpose of the present study was to examine the effect of the administration of naltrexone on craving level after rapid opioid detoxification induced by naltrexone. A naturalistic study was carried out in which patients were followed during 10 months after rapid detoxification. Data about abstinence, relapse, and naltrexone use were collected by means of urine specimens. Craving was measured by the visual analogue scale craving, the Obsessive Compulsive Drug Use Scale, and the Desires for Drug Questionnaire. Results showed that patients who relapsed in opioid use experienced obviously more craving than abstinent people. Patients who took naltrexone did not experience significant less craving than those who did not. These results suggest that the use of opioids is associated with increased craving and that abstinence for opioids is associated with less craving, independent of the use of naltrexone. This is in contrast to the general opinion. Because of the naturalistic design of the study, no firm conclusions can be drawn, but the results grounded the needs of an experimental study.