A 6-month controlled naltrexone study: combined effect with cognitive behavioral therapy in outpatient treatment of alcohol dependence

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Treating posttraumatic stress disorder and alcohol use disorder comorbidity: Current pharmacological therapies and the future of MDMA-integrated psychotherapy

Posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) frequently co-occur in patients who have experienced trauma. This comorbidity leads to a vicious cycle where PTSD symptoms beget heavy drinking and vice versa. There are no FDA-approved medications to treat PTSD-AUD; therefore, individuals suffering from this comorbidity are treated with medication approved to treat the disorders separately or with off-label pharmacological interventions. However, these medications are limited in their efficacy for treating PTSD-AUD comorbidity. Emerging research on the nonclassical psychedelic drug 3,4-methylenedioxymethamphetamine (MDMA) suggests that it may be an effective drug used in conjunction with psychotherapy. The following reviews the current research for clinical pharmacotherapies, as well as MDMA-integrative psychotherapy as they pertain to PTSD and AUD in isolation and co-occurrence. Future directions for the role of psychedelic-integrative therapy for the treatment of this comorbidity are discussed.

Pharmacotherapy for Alcohol Use Disorder: A Systematic Review and Meta-Analysis

Importance

Alcohol use disorder affects more than 28.3 million people in the United States and is associated with increased rates of morbidity and mortality.

Objective

To compare efficacy and comparative efficacy of therapies for alcohol use disorder.

Data Sources

PubMed, the Cochrane Library, the Cochrane Central Trials Registry, PsycINFO, CINAHL, and EMBASE were searched from November 2012 to September 9, 2022 Literature was subsequently systematically monitored to identify relevant articles up to August 14, 2023, and the PubMed search was updated on August 14, 2023.

Study Selection

For efficacy outcomes, randomized clinical trials of at least 12 weeks' duration were included. For adverse effects, randomized clinical trials and prospective cohort studies that compared drug therapies and reported health outcomes or harms were included.

Data Extraction and Synthesis

Two reviewers evaluated each study, assessed risk of bias, and graded strength of evidence. Meta-analyses used random-effects models. Numbers needed to treat were calculated for medications with at least moderate strength of evidence for benefit.

Main Outcomes and Measures

The primary outcome was alcohol consumption. Secondary outcomes were motor vehicle crashes, injuries, quality of life, function, mortality, and harms.

Results

Data from 118 clinical trials and 20 976 participants were included. The numbers needed to treat to prevent 1 person from returning to any drinking were 11 (95% CI, 1-32) for acamprosate and 18 (95% CI, 4-32) for oral naltrexone at a dose of 50 mg/d. Compared with placebo, oral naltrexone (50 mg/d) was associated with lower rates of return to heavy drinking, with a number needed to treat of 11 (95% CI, 5-41). Injectable naltrexone was associated with fewer drinking days over the 30-day treatment period (weighted mean difference, -4.99 days; 95% CI, -9.49 to -0.49 days) Adverse effects included higher gastrointestinal distress for acamprosate (diarrhea: risk ratio, 1.58; 95% CI, 1.27-1.97) and naltrexone (nausea: risk ratio, 1.73; 95% CI, 1.51-1.98; vomiting: risk ratio, 1.53; 95% CI, 1.23-1.91) compared with placebo.

Conclusions and Relevance

In conjunction with psychosocial interventions, these findings support the use of oral naltrexone at 50 mg/d and acamprosate as first-line pharmacotherapies for alcohol use disorder.

Pharmacological Treatment of Alcohol Cravings

(1) Background: The treatment of substance addiction is challenging and has persisted for decades, with only a few therapeutic options. Although there are some recommendations for specific treatments for Alcohol Use Disorder (AUD), there is no specific medication used to treat alcohol cravings, which could benefit millions of patients that are suffering from alcoholism. Cravings, or the urge to use drugs, refer to the desire to experience the effects of a previously experienced psychoactive substance. (2) Methods: We included original studies of alcohol abuse or dependence extracted from a controlled, blind, pharmacological treatment study which presented measures and outcomes related to alcohol cravings. (3) Results: Specific drugs used for the treatment of alcoholism, such as Naltrexone and Acamprosate, have had the best results in relieving craving symptoms, as well as promoting abstinence. Baclofen and anticonvulsants such as Gabapentin and Topiramate have shown good results in promoting abstinence and the cessation of cravings. (4) Conclusions: Specific drugs used for the treatment of alcoholism to obtain the best results can be considered the gold standard for promoting abstinence and relieving cravings. Anticonvulsants and Baclofen also had good results, with these medications being considered as second-line ones. Varenicline is an option for alcohol dependents who also concomitantly ingest tobacco.

The life and times of endogenous opioid peptides: Updated understanding of synthesis, spatiotemporal dynamics, and the clinical impact in alcohol use disorder

The opioid G-protein coupled receptors (GPCRs) strongly modulate many of the central nervous system structures that contribute to neurological and psychiatric disorders including pain, major depressive disorder, and substance use disorders. To better treat these and related diseases, it is essential to understand the signaling of their endogenous ligands. In this review, we focus on what is known and unknown about the regulation of the over two dozen endogenous peptides with high affinity for one or more of the opioid receptors. We briefly describe which peptides are produced, with a particular focus on the recently proposed possible synthesis pathways for the endomorphins. Next, we describe examples of endogenous opioid peptide expression organization in several neural circuits and how they appear to be released from specific neural compartments that vary across brain regions. We discuss current knowledge regarding the strength of neural activity required to drive endogenous opioid peptide release, clues about how far peptides diffuse from release sites, and their extracellular lifetime after release. Finally, as a translational example, we discuss the mechanisms of action of naltrexone (NTX), which is used clinically to treat alcohol use disorder. NTX is a synthetic morphine analog that non-specifically antagonizes the action of most endogenous opioid peptides developed in the 1960s and FDA approved in the 1980s. We review recent studies clarifying the precise endogenous activity that NTX prevents. Together, the works described here highlight the challenges and opportunities the complex opioid system presents as a therapeutic target.

Sodium oxybate for the maintenance of abstinence in alcohol-dependent patients: An international, multicenter, randomized, double-blind, placebo-controlled trial

BACKGROUND

Sodium oxybate (SMO) has been shown to be effective in the maintenance of abstinence (MoA) in alcohol-dependent patients in a series of small randomized controlled trials (RCTs). These results needed to be confirmed by a large trial investigating the treatment effect and its sustainability after medication discontinuation.

AIMS

To confirm the SMO effect on (sustained) MoA in detoxified alcohol-dependent patients.

METHODS

Large double-blind, randomized, placebo-controlled trial in detoxified adult alcohol-dependent outpatients (80% men) from 11 sites in four European countries. Patients were randomized to 6 months SMO (3.3-3.9 g/day) or placebo followed by a 6-month medication-free period. Primary outcome was the cumulative abstinence duration (CAD) during the 6-month treatment period defined as the number of days with no alcohol use. Secondary outcomes included CAD during the 12-month study period.

RESULTS

Of the 314 alcohol-dependent patients randomized, 154 received SMO and 160 received placebo. Based on the pre-specified fixed-effect two-way analysis of variance including the treatment-by-site interaction, SMO showed efficacy in CAD during the 6-month treatment period: mean difference +43.1 days, 95% confidence interval (17.6-68.5; p = 0.001). Since significant heterogeneity of effect across sites and unequal sample sizes among sites (n = 3-66) were identified, a site-level random meta-analysis was performed with results supporting the pre-specified analysis: mean difference +32.4 days, p = 0.014. The SMO effect was sustained during the medication-free follow-up period. SMO was well-tolerated.

CONCLUSIONS

Results of this large RCT in alcohol-dependent patients demonstrated a significant and clinically relevant sustained effect of SMO on CAD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04648423.

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.

Pharmacogenetics of Addiction Therapy

Drug addiction is a serious relapsing disease that has high costs to society and to the individual addicts. Treatment of these addictions is still in its nascency, with only a few examples of successful therapies. Therapeutic response depends upon genetic, biological, social, and environmental components. A role for genetic makeup in the response to treatment has been shown for several addiction pharmacotherapies with response to treatment based on individual genetic makeup. In this chapter, we will discuss the role of genetics in pharmacotherapies, specifically for cocaine, alcohol, and opioid dependences. The continued elucidation of the role of genetics should aid in the development of new treatments and increase the efficacy of existing treatments.

A systematic review of gene-by-intervention studies of alcohol and other substance use

Alcohol and other substance use problems are common, and the efficacy of current prevention and intervention programs is limited. Genetics may contribute to differential effectiveness of psychosocial prevention and intervention programs. This paper reviews gene-by-intervention (G×I) studies of alcohol and other substance use, and implications for integrating genetics into prevention science. Systematic review yielded 17 studies for inclusion. Most studies focused on youth substance prevention, alcohol was the most common outcome, and measures of genotype were heterogeneous. All studies reported at least one significant G×I interaction. We discuss these findings in the context of the history and current state of genetics, and provide recommendations for future G×I research. These include the integration of genome-wide polygenic scores into prevention studies, broad outcome measurement, recruitment of underrepresented populations, testing mediators of G×I effects, and addressing ethical implications. Integrating genetic research into prevention science, and training researchers to work fluidly across these fields, will enhance our ability to determine the best intervention for each individual across development. With growing public interest in obtaining personalized genetic information, we anticipate that the integration of genetics and prevention science will become increasingly important as we move into the era of precision medicine.

Effects of 5-HT2A receptor agonist 2,5-dimethoxy-4-iodoamphetamine on alcohol consumption in Long-Evans rats

The objectives of this study were to determine alcohol consumption after administration of (R)(-)-2,5-dimethoxy-4-iodoamphetamine (DOI) or naltrexone in Long-Evans rats, and to assess the effectiveness of these treatments based on individual differences in alcohol consumption. Adult male Long-Evans rats (N = 16) were given opportunities to orally self-administer a 20% (v/v) ethanol (EtOH) solution using an intermittent access, two-bottle (vs. tap water) choice procedure in their home cages. EtOH consumption and preference, total fluid consumption and food intake were measured. Last, we assessed the effects of naltrexone (1 mg/kg; subcutaneous) and (R)(-)-DOI (0.1-1 mg/kg; subcutaneous) on EtOH intake and preference using a quartile analysis. Rats showed stable EtOH (20%) intake and preference after 15 EtOH access sessions. Naltrexone produced a transient decrease in EtOH intake, but an inconsistent effect on EtOH preference, whereas DOI dose-dependently reduced EtOH intake and preference for at least 24 h. Subsequent quartile analyses revealed that rats with the highest EtOH intake during the first 60 min of access to EtOH showed greater reductions in EtOH intake and preference after DOI treatment. This is the first report to show that DOI-elicited reductions in EtOH intake and preference in rats depend on baseline EtOH intake, perhaps supporting a 'baseline dependency' hypothesis of effectiveness with phenethylamine psychedelics on EtOH consumption. If so, individuals with greater potential to develop severe AUDs may be particularly responsive to the positive motivational changes produced by treatment with psychedelics that target the 5-HT2 receptor family.

The Role of the Family in Alcohol Use Disorder Recovery for Adults

Alcohol use disorder (AUD) and family functioning are inextricably bound, and families are impacted negatively by AUD, but families show substantial improvements with AUD recovery. Family members can successfully motivate a person with AUD to initiate changes in drinking or to seek AUD treatment. During recovery, family members can provide active support for recovery. Several couple- or family-involved treatments for AUD have been developed and tested in rigorous efficacy trials. Efficacious treatments based in family systems theory or cognitive behavioral approaches focus on the concerned family member alone, or they engage the couple or family as a unit in the treatment. However, most treatments have been studied in fairly homogeneous, heterosexual, White, non-Hispanic populations, limiting the potential generalizability of these treatments. Substantial gaps remain in our understanding of family processes associated with the initiation and maintenance of AUD recovery among adults. This review outlines the existing literature and describes opportunities for future research to address knowledge gaps in understanding the mechanisms by which these treatments are efficacious, use of family-based treatments with diverse populations, integration of pharmacotherapies with family-involved treatment, role of families in recovery-oriented systems of care, and how to improve treatment development and dissemination.

The effect of desire thinking on facilitating beliefs in alcohol use disorder: An experimental investigation

Permissive beliefs relate to the acceptability of engaging in alcohol use in spite of obvious potential negative consequences. They are considered the most proximal and precipitating cognitive factor in the decision to use alcohol and/or the activation of strategies to obtain it. Recent research suggested that 'desire thinking' may be involved in the escalation of craving and addictive behaviours and can play a role in strengthening permissive beliefs. The current study tested whether the induction of desire thinking would have a stronger effect on rate of conviction in permissive beliefs compared to a control cognitive response in the form of neutral thinking and whether this effect would be specific for patients with alcohol use disorder (AUD). Thirty AUD patients and 30 social drinkers (SD) were randomly allocated to two thinking manipulation tasks (desire thinking and neutral thinking). Current permissive beliefs were measured before and after manipulation and after a resting phase. Findings showed that desire thinking increased the level of current permissive beliefs after manipulation relative to the neutral thinking condition for the AUD group but not for the SD group. This effect was not purely dependent on the concurrent level of perceived craving. This study supports a causal relationship between the induction of desire thinking and rate of conviction in permissive beliefs and highlights the relevance of targeting desire thinking in the treatment for AUD patients.

Combined Pharmacotherapy and Cognitive Behavioral Therapy for Adults With Alcohol or Substance Use Disorders: A Systematic Review and Meta-analysis

IMPORTANCE

Substance use disorders (SUDs) represent a pressing public health concern. Combined behavioral and pharmacological interventions are considered best practices for addiction. Cognitive behavioral therapy (CBT) is a first-line intervention, yet the superiority of CBT compared with other behavioral treatments when combined with pharmacotherapy remains unclear. An understanding of the effects of combined CBT and pharmacotherapy will inform best-practice guidelines for treatment of SUD.

OBJECTIVE

To conduct a meta-analysis of the published literature on combined CBT and pharmacotherapy for adult alcohol use disorder (AUD) or other SUDs.

DATA SOURCES

PubMed, Cochrane Register, MEDLINE, PsychINFO, and Embase databases from January 1, 1990, through July 31, 2019, were searched. Keywords were specified in 3 categories: treatment type, outcome type, and study design. Collected data were analyzed through September 30, 2019.

STUDY SELECTION

Two independent raters reviewed abstracts and full-text articles. English language articles describing randomized clinical trials examining CBT in combination with pharmacotherapy for AUD and SUD were included.

DATA EXTRACTION AND SYNTHESIS

Inverse-variance weighted, random-effects estimates of effect size were pooled into 3 clinically informative subgroups: (1) CBT plus pharmacotherapy compared with usual care plus pharmacotherapy, (2) CBT plus pharmacotherapy compared with another specific therapy plus pharmacotherapy, and (3) CBT added to usual care and pharmacotherapy compared with usual care and pharmacotherapy alone. Sensitivity analyses included assessment of study quality, pooled effect size heterogeneity, publication bias, and primary substance moderator effects.

MAIN OUTCOMES AND MEASURES

Substance use frequency and quantity outcomes after treatment and during follow-up were examined.

RESULTS

The sample included 62 effect sizes from 30 unique randomized clinical trials that examined CBT in combination with some form of pharmacotherapy for AUD and SUD. The primary substances targeted in the clinical trial sample were alcohol (15 [50%]), followed by cocaine (7 [23%]) and opioids (6 [20%]). The mean (SD) age of the patient sample was 39 (6) years, with a mean (SD) of 28% (12%) female participants per study. The following pharmacotherapies were used: naltrexone hydrochloride and/or acamprosate calcium (26 of 62 effect sizes [42%]), methadone hydrochloride or combined buprenorphine hydrochloride and naltrexone (11 of 62 [18%]), disulfiram (5 of 62 [8%]), and another pharmacotherapy or mixture of pharmacotherapies (20 of 62 [32%]). Random-effects pooled estimates showed a benefit associated with combined CBT and pharmacotherapy over usual care (g range, 0.18-0.28; k = 9). However, CBT did not perform better than another specific therapy, and evidence for the addition of CBT as an add-on to combined usual care and pharmacotherapy was mixed. Moderator analysis showed variability in effect direction and magnitude by primary drug target.

CONCLUSIONS AND RELEVANCE

The present study supports the efficacy of combined CBT and pharmacotherapy compared with usual care and pharmacotherapy. Cognitive behavioral therapy did not perform better than another evidence-based modality (eg, motivational enhancement therapy, contingency management) in this context or as an add-on to combined usual care and pharmacotherapy. These findings suggest that best practices in addiction treatment should include pharmacotherapy plus CBT or another evidence-based therapy, rather than usual clinical management or nonspecific counseling services.

Sigma receptor-induced heavy drinking in rats: Modulation by the opioid receptor system

Alcohol use disorder (AUD) is a major cause of morbidity and mortality worldwide, for which new efficacious treatments are necessary. The opioid receptor system is a mediator of the rewarding effects of alcohol; in particular, while activation of μ opioid receptors enhances ethanol intake in rodents, opioid-receptor antagonists, such as naloxone and naltrexone, reduce its pleasurable and reinforcing effects, thereby decreasing alcohol. Sigma receptors (Sig-Rs) have been proposed as modulators of the effects of alcohol and, therefore, as a potential new pharmacological target for AUD. Somewhat analogously to μ opioid ligands, SigR agonists increase, while SigR antagonists decrease alcohol intake in animal models of excessive alcohol drinking. However, a potential cross-talk between these two receptor systems in relation to alcohol consumption has so far not been investigated. Here, we addressed this question pharmacologically, by testing the effects of either activating or inhibiting opioid receptors on the heavy alcohol drinking induced by chronic stimulation of SigR in alcohol-preferring rats. We found that the opioid receptor agonist morphine, which per se increases ethanol intake, at a sub-threshold dose reduces the binge-like drinking induced by the repeated treatment with the SigR agonist 1,3-di-o-tolylguanidine (DTG); conversely, the opioid receptor antagonist naltrexone, which per se reduces ethanol intake, at a sub-threshold dose potentiates the DTG-induced binge-like drinking. Our data show a cross-talk between the opioid and SigR systems relevant to the modulation of alcohol drinking, which provides important insights into the neurobiology of AUD and may lead to the development of novel therapies, either standalone or in combination.

Vibration of effects from diverse inclusion/exclusion criteria and analytical choices: 9216 different ways to perform an indirect comparison meta-analysis

BACKGROUND

Different methodological choices such as inclusion/exclusion criteria and analytical models can yield different results and inferences when meta-analyses are performed. We explored the range of such differences, using several methodological choices for indirect comparison meta-analyses to compare nalmefene and naltrexone in the reduction of alcohol consumption as a case study.

METHODS

All double-blind randomized controlled trials (RCTs) comparing nalmefene to naltrexone or one of these compounds to a placebo in the treatment of alcohol dependence or alcohol use disorders were considered. Two reviewers searched for published and unpublished studies in MEDLINE (August 2017), the Cochrane Library, Embase, and ClinicalTrials.gov and contacted pharmaceutical companies, the European Medicines Agency, and the Food and Drug Administration. The indirect comparison meta-analyses were performed according to different inclusion/exclusion criteria (based on medical condition, abstinence of patients before inclusion, gender, somatic and psychiatric comorbidity, psychological support, treatment administered and dose, treatment duration, outcome reported, publication status, and risk of bias) and different analytical models (fixed and random effects). The primary outcome was the vibration of effects (VoE), i.e. the range of different results of the indirect comparison between nalmefene and naltrexone. The presence of a "Janus effect" was investigated, i.e. whether the 1st and 99th percentiles in the distribution of effect sizes were in opposite directions.

RESULTS

Nine nalmefene and 51 naltrexone RCTs were included. No study provided a direct comparison between the drugs. We performed 9216 meta-analyses for the indirect comparison with a median of 16 RCTs (interquartile range = 12-21) included in each meta-analysis. The standardized effect size was negative at the 1st percentile (- 0.29, favouring nalmefene) and positive at the 99th percentile (0.29, favouring naltrexone). A total of 7.1% (425/5961) of the meta-analyses with a negative effect size and 18.9% (616/3255) of those with a positive effect size were statistically significant (p < 0.05).

CONCLUSIONS

The choice of inclusion/exclusion criteria and analytical models for meta-analysis can result in entirely opposite results. VoE evaluations could be performed when overlapping meta-analyses on the same topic yield contradictory result.

TRIAL REGISTRATION

This study was registered on October 19, 2016, in the Open Science Framework (OSF, protocol available at https://osf.io/7bq4y/ ).

Design of a randomized controlled trial examining the efficacy of oxytocin to enhance alcohol behavioral couple therapy

Combining pharmacological interventions with evidence-based behavioral interventions may help optimize treatment outcomes for alcohol use disorder (AUD). While several effective behavioral interventions for AUD have been developed, the vast majority target individual patients, despite evidence that behavioral interventions for couples have the ability to outperform individual treatments for AUD. Alcohol Behavioral Couples Therapy (ABCT) is an evidence-based behavioral intervention for couples that has been shown to significantly reduce AUD severity as well as improve relationship functioning. Accumulating evidence suggests that the neuropeptide oxytocin has the ability to reduce alcohol craving and consumption, symptoms of tolerance and withdrawal, and ameliorate neurobiological deficits associated with AUD. Furthermore, oxytocin has demonstrated the ability to increase prosocial behavior and cognition, and restore sensitivity to natural rewards such as interpersonal relationships. No study to date has examined the ability of oxytocin to enhance ABCT. Thus, the primary objective of this Phase II study is to examine the effects of oxytocin versus placebo in combination with ABCT in reducing AUD severity and improving relationship functioning. We also will utilize neuroimaging techniques before and after treatment to investigate the underlying pathophysiology of AUD among couples and identify prognostic indicators of treatment outcome. The findings from this study might provide critical new information to help inform clinical practice and accelerate research on the pharmacological treatment of AUD.

Mu opioid receptors in GABAergic neurons of the forebrain promote alcohol reward and drinking

Mu opioid receptors (MORs) are widely distributed throughout brain reward circuits and their role in drug and social reward is well established. Substantial evidence has implicated MOR and the endogenous opioid system in alcohol reward, but circuit mechanisms of MOR-mediated alcohol reward and intake behavior remain elusive, and have not been investigated by genetic approaches. We recently created conditional knockout (KO) mice targeting the Oprm1 gene in GABAergic forebrain neurons. These mice (Dlx-MOR KO) show a major MOR deletion in the striatum, whereas receptors in midbrain (including the Ventral Tegmental Area or VTA) and hindbrain are intact. Here, we compared alcohol-drinking behavior and rewarding effects in total (MOR KO) and conditional KO mice. Concordant with our previous work, MOR KO mice drank less alcohol in continuous and intermittent two-bottle choice protocols. Remarkably, Dlx-MOR KO mice showed reduced drinking similar to MOR KO mice, demonstrating that MOR in the forebrain is responsible for the observed phenotype. Further, alcohol-induced conditioned place preference was detected in control but not MOR KO mice, indicating that MOR is essential for alcohol reward and again, Dlx-MOR KO recapitulated the MOR KO phenotype. Taste preference and blood alcohol levels were otherwise unchanged in mutant lines. Together, our data demonstrate that MOR expressed in forebrain GABAergic neurons is essential for alcohol reward-driven behaviors, including drinking and place conditioning. Challenging the prevailing VTA-centric hypothesis, this study reveals another mechanism of MOR-mediated alcohol reward and consumption, which does not necessarily require local VTA MORs but rather engages striatal MOR-dependent mechanisms.

Metacognitive Therapy for Alcohol Use Disorder: A Systematic Case Series

Alcohol Use Disorder (AUD) is a debilitating condition with serious adverse effects on health and psycho-social functioning. The most effective psychological treatments for AUD show moderate efficacy and return to dysregulated alcohol use after treatment is still common. The aim of the present study was to evaluate Metacognitive Therapy (MCT) as applied to AUD. Five patients were treated using a non-concurrent multiple baseline design with follow-up at 3- and 6-months time points. Each patient received 12 one-hour sessions of MCT. Following MCT all patients demonstrated large and clinically meaningful reductions in weekly alcohol use and number of binge drinking episodes that were upheld at follow-up in almost all cases. Metacognitive beliefs, as secondary outcome, also changed substantially. The findings from this study offer preliminary evidence of positive effects associated with MCT in AUD and support the need for a definitive trial of MCT in addictive behaviors.

Association between alcoholic interventions and abstinence rates for alcohol use disorders: A meta-analysis

OBJECTIVE

The aim of present study is to quantitatively evaluate the association between different interventions and abstinence rates based on network meta-analysis.

METHOD

Following PRISMA guidelines, randomized clinical trials that compared different alcoholic interventions for alcohol use disorders associated with abstinence rates in treatment sessions or/and follow-up sessions were recruited. Main data synthesis was performed by Bayesian random-effects network meta-analyses, and the relative ranking of interventions was estimated by cumulative probability P values (SUCRA). Funnel plot symmetry was used to detect publication bias. Moreover, pair-wised comparison was also conducted to determine the statistical difference and forest plots were generated to calculate the differences between the groups. The Grades of Recommendations Assessment, Development and Evaluation (GRADE) criteria were utilized for the recommendations of evidence from pairwise direct comparisons.

RESULTS

A total of 137 RCTs containing 27,282 participants and 8 variations of psychotherapy, pharmacotherapy, contingency management, and brief intervention used as treatment interventions were included. In summary, contingency management plus psychotherapy was demonstrated to be effective and possessed the best rank of achieving the highest abstinence rate in treatment sessions (SUCRA, 0.61). Pharmacotherapy plus psychotherapy also revealed its efficacy and was associated with the highest abstinence rate in follow-up sessions (SUCRA, 0.40). More importantly, psychotherapy alone was demonstrated not to be associated with higher abstinence rates in both treatment (OR, 1.052; 95% CI, 0.907-1.220) and follow-up sessions (OR, 0.967; 95% CI, 0.552-1.693), yet pharmacotherapy seemed to be the only intervention associated with higher abstinence rates compared to controls in both sessions (treatment session: OR, 1.074; 95% CI, 1.002-1.152) (follow-up session: OR, 1.442; 95% CI, 1.094-1.900).

CONCLUSIONS

Contingency management plus psychotherapy and pharmacotherapy plus psychotherapy were demonstrated to be associated with the highest abstinence rates in treatment sessions and follow-up sessions, respectively. However, contingency management and pharmacotherapy seemed to be the substantial crucial factors allowing for the maintenance of the highest abstinence rates in respective sessions, although we need more evidence for further validation.

Adding Psychotherapy to the Naltrexone Treatment of Alcohol Use Disorder: Meta-analytic Review

Background

It remains unclear if naltrexone combined with psychotherapy is superior to naltrexone alone in treating alcohol use disorders (AUD). The current meta-analysis examined the hypothesis that psychotherapy is a significant moderator that influences AUD-related outcomes and that naltrexone combined with psychotherapy is associated with significantly better AUD-related outcomes than naltrexone alone.

Methods

A total of 30 studies (N_naltrexone = 2317; N_placebo = 2056) were included. Random effects model meta-analyses were carried out for each of the studied outcomes. Subsequently, the random effects model pooled estimates from studies with and without psychotherapy were compared using a Wald test. A mixed-effect model, incorporating psychotherapy as a moderator, was used to examine the impact of psychotherapy on treatment outcomes.

Results

Naltrexone had a significant treatment effect on abstinence relapse and Gamma-Glutamyl Transferase levels, but not cravings. The pooled estimates for studies with and without psychotherapy were not significantly different for any of the studied outcomes. Psychotherapy was not a significant moderator in the mixed effects models for any of the studied outcomes.

Conclusions

Naltrexone treatment is efficacious in reducing alcohol consumption, but not reducing cravings. Adding psychotherapy on top naltrexone did not result in any significant additional benefit for AUD patients.

Duration of therapy - Does it matter?: A systematic review and meta-regression of the duration of psychosocial treatments for alcohol use disorder

BACKGROUND

The recommendations in clinical guidelines for duration of therapy for alcohol use disorder (AUD) are based on consensus decisions. In reality, we do not know the optimal duration of an alcohol treatment course.

METHODS

A systematic review and meta-regression of randomized controlled trials of psychosocial treatment in alcohol outpatient treatment centers. The population consisted of adults suffering from AUD, treated in an outpatient facility with at least two sessions of therapy. Meta-regression analysis was performed with treatment outcome as a function of duration of therapy across studies. Treatment outcome was defined as long-term alcohol use measured in percentage of days abstinent (PDA), percentage of heavy days drinking (PHD), and/or proportion of participants abstinent (ABS).

RESULTS

48 studies encompassing 8984 participants. Mean planned duration of therapy: 18 (8-82) weeks and 14 (2-36) sessions. Mean actual attended sessions: 9 (1-26). Mean follow-up time: 43 (8-104) weeks with a mean of 6 (2-18) research assessments. Neither planned weeks, duration of sessions, frequency of sessions per week, nor actual attended sessions were associated with long-term alcohol use outcomes. However, frequency of research assessments was positively associated with PDA and PHD.

CONCLUSION

No associations between long-term alcohol use outcomes and planned or actual attended duration of psychosocial treatment in outpatient care. Research assessments and, accordingly, the research project in itself may influence outcome in studies of psychosocial treatment for alcohol use disorder.

Medications development for the treatment of alcohol use disorder: insights into the predictive value of animal and human laboratory models

Development of effective treatments for alcohol use disorder (AUD) represents an important public health goal. This review provides a summary of completed preclinical and clinical studies testing pharmacotherapies for the treatment of AUD. We discuss opportunities for improving the translation from preclinical findings to clinical trial outcomes, focusing on the validity and predictive value of animal and human laboratory models of AUD. Specifically, while preclinical studies of medications development have offered important insights into the neurobiology of the disorder and alcohol's molecular targets, limitations include the lack of standardized methods and streamlined processes whereby animal studies can readily inform human studies. Behavioral pharmacology studies provide a less expensive and valuable opportunity to assess the feasibility of a pharmacotherapy prior to initiating larger scale clinical trials by providing insights into the mechanism of the drug, which can then inform recruitment, analyses, and assessments. Summary tables are provided to illustrate the wide range of preclinical, human laboratory, and clinical studies of medications development for alcoholism. Taken together, this review highlights the challenges associated with animal paradigms, human laboratory studies, and clinical trials with the overarching goal of advancing treatment development and highlighting opportunities to bridge the gap between preclinical and clinical research.

Ethnic differences in the effectiveness of cognitive behavioral therapy combined with medication: Comparing Asian American and white psychiatric patients

Several meta-analyses have demonstrated the effectiveness of treatment utilizing cognitive behavioral therapy (CBT) combined with medication. There is, however, a paucity of research comparing the effectiveness of this combined treatment with psychiatric patients from different ethnic backgrounds. This study is the first of its kind to compare the effectiveness of CBT combined with medication for Asian American and White patients' psychiatric symptom severity levels of depression, anxiety, psychological well-being, and quality of life. The study examined the effects of CBT combined with medication for 43 Asian American and 43 White Non-Hispanic patients at an acute psychiatric partial hospital. A 2×2 between-within repeated measures analysis of variance was used. Results indicated significant improvement after treatment in all symptom categories assessed for the Asian American and White patients. The findings displayed trends over the course of treatment toward a greater decrease in anxiety symptoms among Asian patients but a larger increase in functioning level among White patients. In conclusion, the findings from this study provide preliminary cross-cultural support for CBT combined with medication as a treatment in partial hospital settings and suggest that the effectiveness of such treatments is similar across cultural groups.

Evaluation in alcohol use disorders - insights from the nalmefene experience

Nalmefene was the first treatment approved by the European Medicines Agency for reducing alcohol consumption in adult patients with alcohol dependence. It is often presented as a paradigm shift in therapeutics, but major issues limit the interpretation of the evidence supporting its use. The randomised trials submitted provided no evidence of harm reduction, the differences on consumption outcomes were of questionable clinical relevance, the target population was defined a posteriori and the drug was compared to a placebo although naltrexone was already used off-label. No post-approval randomised study is currently designed to clearly address these issues. In addition, nalmefene trials have been uncritically cited, even in guidelines. This experience reveals weaknesses in drug evaluations in alcohol dependence, which call for changes. We propose to dispense with alcohol consumption as a surrogate outcome, to consider comparative effectiveness issues, and to recommend randomised post-approval studies in case of controversial approval.

Mechanisms of symptom reduction in a combined treatment for comorbid posttraumatic stress disorder and alcohol dependence

OBJECTIVE

To examine the mechanisms of prolonged exposure (PE) and naltrexone (NAL) that underlie symptom reduction among individuals with comorbid posttraumatic stress disorder (PTSD) and alcohol dependence (AD). We hypothesized that (a) reduction in negative cognitions mediates PTSD improvement during PE; (b) reduction in alcohol craving mediates reduction in drinking frequency during NAL treatment; and (c) PTSD improvement mediates reduction in craving and alcohol use during PE.

METHOD

Participants were 159 individuals meeting the DSM-IV diagnosis of PTSD and AD randomly assigned to 1 of 4 conditions: PE + NAL, PE + placebo (PBO), supportive counseling (SC) + NAL; and SC + PBO. All participants received supportive counseling.

RESULTS

Lagged multilevel mediational analyses indicated that (a) a reciprocal relationship between cognitive change and PTSD improvement was observed in PE + NAL, PE + PBO, and SC + NAL, but not in SC + PBO; (b) reduction in craving significantly mediated subsequent decrease in alcohol use in PE + NAL and SC + PBO, but not in PE + PBO and SC + NAL; and (c) PTSD improvement significantly mediated subsequent reduction of craving in PE + PBO, and mediated decrease in alcohol use in PE + NAL.

CONCLUSIONS

The efficacy of combining PE and NAL for reducing alcohol use among those with comorbid PTSD/AD seems to be through reduction in both PTSD symptoms and craving. These findings shed light on the mechanism of PE and highlight the central role of PTSD in the maintenance of alcohol craving and use in patients with comorbid PTSD/AD.

The opioid receptors as targets for drug abuse medication

The endogenous opioid system is largely expressed in the brain, and both endogenous opioid peptides and receptors are present in areas associated with reward and motivation. It is well known that this endogenous system plays a key role in many aspects of addictive behaviours. The present review summarizes the modifications of the opioid system induced by chronic treatment with drugs of abuse reported in preclinical and clinical studies, as well as the action of opioid antagonists and agonists on the reinforcing effects of drugs of abuse, with therapeutic perspectives. We have focused on the effects of chronic psychostimulants, alcohol and nicotine exposure. Taken together, the changes in both opioid peptides and opioid receptors in different brain structures following acute or chronic exposure to these drugs of abuse clearly identify the opioid system as a potential target for the development of effective pharmacotherapy for the treatment of addiction and the prevention of relapse.

The efficacy of acamprosate and naltrexone in the treatment of alcohol dependence, Europe versus the rest of the world: a meta-analysis

AIMS

To determine the efficacy of acamprosate and naltrexone in the treatment of those who are alcohol-dependent in reducing lapse/relapse to alcohol consumption and treatment discontinuation, and to examine whether a proportion of the variance in study outcome can be explained by the country in which the trials have taken place.

METHOD

A systematic review and meta-analysis of randomized controlled trials published before September 2013 was conducted. The primary outcome measures were the efficacy of acamprosate or naltrexone in reducing lapse/relapse compared to placebo in the treatment of alcohol dependence and treatment discontinuation. Twenty-two randomized controlled trials (RCTs) of the efficacy of acamprosate met inclusion criteria for the meta-analysis, with a total of 2649 participants in the acamprosate group and 2587 in the placebo group. Twenty-seven RCTs of the efficacy of naltrexone met inclusion criteria for the meta-analysis, with a total of 2253 participants in the naltrexone group and 1946 in the placebo group. A random-effects model using a Mantel-Haenszel method was applied to conduct the meta-analysis. Variance in study outcomes was explored using subgroup analysis of Europe versus the rest of the world (ROW).

RESULTS

The risk of returning to any drinking at 6 months was significantly lower for acamprosate [risk ratio (RR) = 0.83, 95% confidence interval (CI) = 0.78-0.89]. There was little difference in the risk of participants discontinuing treatment for any reason (RR = 0.91, 95% CI = 0.83-1.00) or due to adverse events (RR = 1.30, 95% CI = 0.96-1.75) for the acamprosate compared to placebo groups. The risk of individuals returning to any drinking at approximately 3 months was reduced significantly for the naltrexone group (RR = 0.92, 95% CI = 0.86-1.00), as was the risk of individuals relapsing to heavy drinking at 3 months (RR = 0.85, 95% CI = 0.78-0.93). There was no significant difference between naltrexone and placebo for the risk of individuals discontinuing treatment for any reason (RR = 0.94, 95% CI = 0.84-1.05). There was a significantly greater risk of participants in the naltrexone group discontinuing treatment due to adverse events compared to placebo (RR = 1.72, 95% CI = 1.10-2.70). Subgroup analysis by country (Europe versus ROW) revealed no difference in risk between acamprosate and placebo for the outcomes returning to any drinking at 6 months and discontinuing treatment due to adverse events. For the outcome discontinuation of treatment for any reason, there was a significant difference in RR between Europe and the ROW (χ(2)  = 11.65, P <0.001) for acamprosate. Acamprosate was associated with a reduction in risk of discontinuing treatment for Europe (RR = 0.86, 95% CI = 0.79-0.95), but an increase in risk of discontinuing treatment for ROW (RR = 1.23, 95% CI = 1.03-1.48).

CONCLUSIONS

Both acamprosate and naltrexone appear to reduce the risk of individuals returning to drinking alcohol in those who are alcohol-dependent. The country in which a randomized control trial (RCT) for the efficacy of acamprosate and naltrexone is completed does not appear to explain the variance in trial outcomes for returning to drinking alcohol or discontinuing drinking due to adverse effects. However, the country in which the RCT of acamprosate are completed may be important for explaining the variance between studies for the outcome 'discontinuing treatment for any reason'.

Sex differences in the effects of adolescent social deprivation on alcohol consumption in μ-opioid receptor knockout mice

RATIONALE

Evidence based on clinical and experimental animal studies indicates that adolescent social deprivation influences alcohol consumption in a sex-dependent manner, perhaps by influencing stress responses. However, the mechanisms underlying the interaction between these phenomena remain to be elucidated. Since the μ-opioid receptor (MOP) has been reported to have key roles in social stress responses as well as the reinforcing/addictive effects of ethanol, MOP is a candidate molecule that may link adolescent social deprivation and subsequent alterations in alcohol consumption.

OBJECTIVES

To evaluate the involvement of MOP and social isolation-induced changes in alcohol consumption, as well as the effect of sex differences on responses to social isolation, alcohol consumption was assessed using a two-bottle home-cage consumption procedure (8 % ethanol vs. water) in MOP knockout (MOP-KO) and wild type (WT) mice of both sexes exposed to adolescent social deprivation or reared socially.

RESULTS

Isolation rearing had no effects upon alcohol consumption of WT mice, whereas it significantly altered alcohol consumption in both male and female MOP-KO mice. Interestingly, social isolation affected ethanol consumption differently in male and female mice. Ethanol consumption was increased in male MOP-KO mice, but decreased in female MOP-KO mice, by isolation rearing.

CONCLUSION

These results indicate that disturbances of MOP function influence the effects of isolation rearing on ethanol consumption in a sex-dependent manner. Consequently, this suggests the possibility that genetic variation that influences MOP function may have differential roles in alcoholism in men and women, and alcoholism treatments that target MOP function may be differentially effective in males and females.

Pharmacological Options for Smoking Cessation in Heavy-Drinking Smokers

There is a high prevalence of comorbid tobacco use and alcohol use disorder (AUD), affecting more than 6 million people in the US. Globally, tobacco and alcohol use rank fourth and fifth, respectively, for disability-adjusted life-years lost. Levels of alcohol use are higher in smokers than nonsmokers, and the prevalence of smoking is higher in heavy drinkers compared with nondrinkers. This relationship is driven by many different factors, including genetics, neurobiological mechanisms, conditioning processes, and psychosocial influences. Although this unique population tends to experience more negative health consequences, more severe AUD, and poorer response to treatment than those with either AUD or tobacco use disorder alone, there are currently no available treatment protocols tailored to this comorbid condition. In this review, we provide a comprehensive review of ongoing clinical research into smoking cessation options for heavy-drinking smokers (HDS) through an evaluation of the effect of promising novel pharmacotherapies as well as combination therapies, including varenicline, naltrexone, the combination of varenicline and naltrexone, and the combination of naltrexone and nicotine replacement therapy (NRT). These treatments are considered in light of the standard of care for smoking cessation, and seek to improve upon the available guidelines for this sizeable subgroup of smokers, namely those smokers who drink heavily.

Posttraumatic stress disorder and alcohol dependence: does order of onset make a difference?

Posttraumatic stress disorder (PTSD) and alcohol dependence (AD) are frequently comorbid and the order in which they develop may affect the clinical presentation and response to treatment. This study compared 73 treatment-seeking participants who developed PTSD prior to developing AD ("PTSD-first") with 64 participants who developed AD prior to developing PTSD ("AD-first") on demographics, clinical presentation, and response to treatment for PTSD and AD. All participants received BRENDA, a medication management and motivational enhancement intervention and were randomly assigned to either prolonged exposure (PE) for PTSD plus BRENDA or BRENDA alone and to either naltrexone (NAL) for AD or placebo (PBO). Results showed that participants with AD-first were more likely to report low income, meet criteria for antisocial or borderline personality disorder, report an index trauma of physical assault, compared to those with PTSD-first. Conversely, participants with PTSD-first were more likely to report an index trauma of sexual assault or a combat experience. Notably, no group differences were observed in treatment outcome despite some differences in clinical presentation.

Varenicline, low dose naltrexone, and their combination for heavy-drinking smokers: human laboratory findings

RATIONALE

Heavy-drinking smokers constitute a sizeable and hard-to-treat subgroup of smokers, for whom tailored smoking cessation therapies are not yet available.

OBJECTIVES

The present study used a double-blind, randomized, 2 × 2 medication design, testing varenicline alone (VAR; 1 mg twice daily), low dose naltrexone alone (L-NTX; 25 mg once daily), varenicline plus naltrexone, and placebo for effects on cigarette craving and subjective response to alcohol and cigarettes in a sample (n = 130) of heavy-drinking daily smokers (≥10 cigarettes/day).

METHODS

All participants were tested after a 9-day titration period designed to reach a steady state on the target medication. Testing was completed at 12 h of nicotine abstinence, after consuming a standard dose of alcohol (target breath alcohol concentration = 0.06 g/dl) and after smoking the first cigarette of the day.

RESULTS

The combination of VAR + L-NTX was superior to placebo, and at times superior to monotherapy, in attenuating cigarette craving, cigarette and alcohol "high," and in reducing ad-lib consumption of both cigarettes and alcohol during the 9-day medication titration period.

CONCLUSIONS

These preliminary findings indicate that clinical studies of the combination of VAR + L-NTX for heavy drinkers trying to quit smoking are warranted and may ultimately improve clinical care for this sizeable and treatment-resistant subgroup of smokers.

Pharmacogenetics of addiction therapy

Drug addiction is a serious relapsing disease that has high costs to society and to the individual addicts. Treatment of these addictions is still in its nascency, with only a few examples of successful therapies. Therapeutic response depends upon genetic, biological, social, and environmental components. A role for genetic makeup in the response to treatment has been shown for several addiction pharmacotherapies. For several addiction pharmacotherapies, response to treatment varies based on individual genetic makeup. In this chapter, we discuss the role of genetics in pharmacotherapies, specifically for cocaine, alcohol, and opioid dependences. The elucidation of the role of genetics should aid in the development of new treatments and increase the efficacy of existing treatments.

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.

Placebo group improvement in trials of pharmacotherapies for alcohol use disorders: a multivariate meta-analysis examining change over time

OBJECTIVE

Placebo group improvement in pharmacotherapy trials has been increasing over time across several pharmacological treatment areas. However, it is unknown to what degree increasing improvement has occurred in pharmacotherapy trials for alcohol use disorders or what factors may account for placebo group improvement. This meta-analysis of 47 alcohol pharmacotherapy trials evaluated (1) the magnitude of placebo group improvement, (2) the extent to which placebo group improvement has been increasing over time, and (3) several potential moderators that might account for variation in placebo group improvement.

METHOD

Random-effects univariate and multivariate analyses were conducted that examined the magnitude of placebo group improvement in the 47 studies and several potential moderators of improvement: (a) publication year, (b) country in which the study was conducted, (c) outcome data source/type, (d) number of placebo administrations, (e) overall severity of study participants, and (f) additional psychosocial treatment.

RESULTS

Substantial placebo group improvement was found overall and improvement was larger in more recent studies. Greater improvement was found on moderately subjective outcomes, with more frequent administrations of the placebo, and in studies with greater participant severity of illness. However, even after controlling for these moderators, placebo group improvement remained significant, as did placebo group improvement over time.

CONCLUSIONS

Similar to previous pharmacotherapy placebo research, substantial pretest to posttest placebo group improvement has occurred in alcohol pharmacotherapy trials, an effect that has been increasing over time. However, several plausible moderator variables were not able to explain why placebo group improvement has been increasing over time.

The placebo effect in clinical trials for alcohol dependence: an exploratory analysis of 51 naltrexone and acamprosate studies

BACKGROUND

The placebo effect often undermines efforts to determine treatment effectiveness in clinical trials. A significant placebo response occurs in alcohol trials, but it is not well understood. The purpose of this study was to characterize the placebo response across multiple naltrexone and acamprosate studies.

METHODS

Fifty-one trials, 3 with a naltrexone and an acamprosate arm, 31 with at least 1 naltrexone arm, and 17 with at least 1 acamprosate arm, were identified from Cochrane reviews and PubMed search. To be included in this study, patients had to be at least 18 years old, abstinent from alcohol before randomization, and meet a diagnosis of alcohol dependence. Pearson correlation coefficients (rp ) and simple linear regression were used to describe the strength of linear relationships between placebo response and treatment effect size. Spearman's rank correlation coefficients (rs ) were used to examine the strength of associations between study characteristics and placebo response.

RESULTS

For the end point measures of percent days abstinent and total abstinence, a negative relationship was evident between placebo response and treatment effect size in the naltrexone trials (rp  = -0.55, p < 0.01 and rp  = -0.20, p = 0.35, respectively) as well as in the acamprosate trials (rp  = -0.45, p = 0.09 and rp  = -0.56, p = 0.01, respectively). The placebo response for percent days abstinent was negatively correlated with mean age of participants (rs  = -0.42, p = 0.05) across naltrexone trials and positively correlated with publication year (rs  = 0.57, p = 0.03) across acamprosate trials. However, these 2 study characteristics were not significantly correlated with treatment effect size.

CONCLUSIONS

The placebo response varied considerably across trials and was negatively correlated with the treatment effect size. Additional studies are required to fully understand the complex nature of the placebo response and to evaluate approaches to minimize its effects.

The μ-opioid receptor and treatment response to naltrexone

AIMS

To evaluate the pharmacogenetic evidence relating to the use of opioid antagonists (in particular naltrexone) in treating patients with alcohol abuse problems.

METHODS

Narrative review of pre-clinical and clinical published research regarding genetic modulation of psychotropic effects produced by alcohol and the therapeutic effects of opioid antagonists.

RESULTS

Alcohol activates brain reward pathways, leading to positive reinforcement of alcohol seeking and consumption. Thus, the underlying biological mechanisms may be targets for treatment, particularly in the early stages of addiction development. Alcohol reward is in part mediated by endogenous opioids. A single-nucleotide polymorphism (SNP) within the OPRM1 gene, A118G, leading to an amino acid change (Asn40Asp) in the extracellular portion of the receptor, has been implicated in alcoholism as well as in drug addiction, pain sensitivity and stress response, and in animal and human studies relates to the alcohol-dependent phenotype as well as to the treatment response to the µ-opioid antagonist naltrexone.

CONCLUSION

The effect size reported in naltrexone clinical studies is often small, which may be due to heterogeneity among patients. Pharmacogenetic approaches may help guide us in the search for the appropriate treatment optimal for one patient's need.

Meta-analysis of naltrexone and acamprosate for treating alcohol use disorders: when are these medications most helpful?

AIMS

Although debates over the efficacy of oral naltrexone and acamprosate in treating alcohol use disorders tend to focus on their global efficacy relative to placebo or their efficacy relative to each other, the underlying reality may be more nuanced. This meta-analysis examined when naltrexone and acamprosate are most helpful by testing: (i) the relative efficacy of each medication given its presumed mechanism of action (reducing heavy drinking versus fostering abstinence) and (ii) whether different ways of implementing each medication (required abstinence before treatment, detoxification before treatment, goal of treatment, length of treatment, dosage) moderate its effects.

METHODS

A systematic literature search identified 64 randomized, placebo-controlled, English-language clinical trials completed between 1970 and 2009 focused on acamprosate or naltrexone.

RESULTS

Acamprosate had a significantly larger effect size than naltrexone on the maintenance of abstinence, and naltrexone had a larger effect size than acamprosate on the reduction of heavy drinking and craving. For naltrexone, requiring abstinence before the trial was associated with larger effect sizes for abstinence maintenance and reduced heavy drinking compared with placebo. For acamprosate, detoxification before medication administration was associated with better abstinence outcomes compared with placebo.

CONCLUSIONS

In treatment for alcohol use disorders, acamprosate has been found to be slightly more efficacious in promoting abstinence and naltrexone slightly more efficacious in reducing heavy drinking and craving. Detoxification before treatment or a longer period of required abstinence before treatment is associated with larger medication effects for acamprosate and naltrexone respectively.

Do manualized psychosocial interventions help reduce relapse among alcohol-dependent adults treated with naltrexone or placebo? A meta-analysis

BACKGROUND

 During the past decade, several novel medication treatments and psychosocial interventions have been tested. Overall, their impact on reducing alcohol use and preventing relapse has been modest. These outcomes have spurred researchers to investigate whether the addition of manualized psychosocial therapies with demonstrated efficacy to pharmacotherpy would have a synergistic effect.

OBJECTIVES

 We conducted a meta-analysis to test the hypothesis that the addition of manualized psychosocial therapies would reduce the frequency of relapse.

RESULTS

 This review analyzed data from six studies. Among studies that used random assignment to manually guided psychosocial interventions, the rates of relapse between the naltrexone plus a psychosocial intervention and naltrexone without a psychosocial intervention were very similar. Among patients allocated to placebo, similar rates of relapse were also found between Cognitive Behavioral Therapy (CBT) and non-CBT. In studies which used manualized psychotherapies as a platform, relapse rates were similar between naltrexone and placebo. In contrast, studies using Treatment As Usual psychotherapy as a platform demonstrated lower rates of relapse in the naltrexone group, compared to placebo group.

CONCLUSIONS

 We conclude that CBT does not appear to offer benefits beyond those derived from study medications.

SCIENTIFIC SIGNIFICANCE

 The benefit of the addition of CBT to medication in preventing relapse may be limited.

Delta and kappa opioid receptor polymorphisms influence the effects of naltrexone on subjective responses to alcohol

Naltrexone, one of four FDA-approved pharmacotherapies for alcohol dependence, has shown moderate efficacy in clinical trials. Pharmacogenetic effects have been reported such that allelic variation at the gene encoding the mu-opioid receptor (OPRM1, rs1799971) predicts naltrexone-induced blunting of the positively reinforcing effects of alcohol. However, naltrexone also binds, albeit to a lesser degree, to kappa and delta opioid receptors in the brain. This alternate binding presents the possibility that single nucleotide polymorphisms (SNPs) in the kappa and delta opioid receptor (OPRK1 and OPRD1) genes may contribute to naltrexone pharmacogenetics. Therefore, the goal of this exploratory study was to re-examine data from a double-blind placebo controlled laboratory trial of naltrexone for pharmacogenetic effects at kappa and delta opioid receptor tag SNPs. Participants were 40 heavy drinkers (12 female) who underwent an intravenous alcohol challenge paradigm after receiving naltrexone (50mg) or placebo in randomized and crossover fashion. Dependent variables were self-reported alcohol-induced stimulation, sedation, and craving. Multilevel models revealed a significant Naltrexone×OPRK1 Genotype (rs997917) interaction predicting alcohol-induced sedation, such that TT homozygotes reported lower naltrexone-induced alcohol sedation as compared to carriers of the C allele. Moreover, there was a significant Naltrexone×OPRD1 Genotype (rs4654327) interaction predicting alcohol-induced stimulation and craving, such that carriers of the A allele at this locus reported greater naltrexone-induced blunting of alcohol stimulation and alcohol craving compared to GG homozygotes. These findings suggest that additional pharmacogenetic effects in the opioid receptor system may account for individual differences in response to naltrexone in the human laboratory.

BAP updated guidelines: evidence-based guidelines for the pharmacological management of substance abuse, harmful use, addiction and comorbidity: recommendations from BAP

The British Association for Psychopharmacology guidelines for the treatment of substance abuse, harmful use, addiction and comorbidity with psychiatric disorders primarily focus on their pharmacological management. They are based explicitly on the available evidence and presented as recommendations to aid clinical decision making for practitioners alongside a detailed review of the evidence. A consensus meeting, involving experts in the treatment of these disorders, reviewed key areas and considered the strength of the evidence and clinical implications. The guidelines were drawn up after feedback from participants. The guidelines primarily cover the pharmacological management of withdrawal, short- and long-term substitution, maintenance of abstinence and prevention of complications, where appropriate, for substance abuse or harmful use or addiction as well management in pregnancy, comorbidity with psychiatric disorders and in younger and older people.

Understanding naltrexone mechanism of action and pharmacogenetics in Asian Americans via behavioral economics: a preliminary study

A behavioral economic approach to understanding the relative value of alcohol may be useful for advancing medication development for alcoholism. Naltrexone is a heavily researched and moderately effective treatment for alcohol dependence making it a good candidate for a proof-of-concept study of behavioral economics and alcoholism pharmacotherapy. This study examines naltrexone efficacy and pharmacogenetics in terms of the relative value of alcohol, assessed via demand curve analysis. Participants were 35 heavy drinking (AUDIT ≥8) Asian Americans. A within-subjects cross-over medication design was used along with an intravenous alcohol challenge completed after 4 days of both naltrexone and placebo. At baseline and BrAC = 0.06g/dl, participants completed an Alcohol Purchase Task, which assessed estimated alcohol consumption along escalating prices. Behavioral economic demand curve analysis yielded measures of intensity, elasticity, maximum expenditure (O(max)), proportionate price insensitivity (P(max)) and breakpoint. Compared to placebo, naltrexone significantly reduced intensity, O(max) and breakpoint. There were also trend-level medication effects on P(max). BrAC was associated with increases in P(max) and breakpoint. A significant naltrexone × OPRM1 genotype interaction was observed for intensity of demand. The present study extends the literature on naltrexone's mechanisms through the application of a novel behavioral economic paradigm. These results indicate that naltrexone reduces several indices of demand for alcohol. This preliminary report provides further evidence for the effectiveness of naltrexone and supports the utility of a behavioral economic approach to alcoholism pharmacotherapy development.

A randomized clinical trial of naltrexone and behavioral therapy for problem drinking men who have sex with men

OBJECTIVE

This study tested the comparative effectiveness of modified behavioral self-control therapy (MBSCT) and naltrexone (NTX), as well as the added benefit of combining the 2, in problem drinking men who have sex with men (MSM) seeking to reduce but not quit drinking.

METHOD

Participants (N = 200) were recruited and urn randomized to 1 of 2 medication conditions, NTX or placebo (PBO), and either MSBCT or no behavioral intervention, yielding 4 conditions: PBO, NTX, MSBCT, and NTX + MSBCT. In addition, all participants received a brief medication compliance intervention. Participants were treated for 12 weeks and assessed 1 week after treatment completion. Two primary outcomes-sum of standard drinks and number of heavy drinking days-and 1 secondary outcome-percentage of those drinking in a nonhazardous manner (NoH)-were selected a priori.

RESULTS

There was a significant main effect for MBSCT (all ps < .01) but not NTX on all 3 outcomes. In addition, the combination of NTX and MBSCT was not more effective than either MSCBT or PBO. There was a significant interaction effect on NoH, such that NTX significantly increased the likelihood (odds ratio = 3.3) of achieving a nonhazardous drinking outcome relative to PBO. In addition, NTX was significantly more effective than PBO on a descriptive outcome: negative consequences of drinking.

CONCLUSIONS

There was no advantage to adding NTX to MBSCT. In addition, MBSCT showed stronger evidence of efficacy than NTX. At the same time, NTX delivered in the context of a minimal medication compliance intervention was significantly more effective than PBO on an important clinical indicator. Results provide new information to guide the treatment of problem drinking, including in primary care settings.

Pharmacogenetics of naltrexone in asian americans: a randomized placebo-controlled laboratory study

Recent clinical and laboratory studies have shown that the effects of naltrexone for alcoholism may be moderated by the Asn40Asp single-nucleotide polymorphism (SNP) of the μ-opioid receptor gene (OPRM1). Allele frequencies for this polymorphism, however, have been shown to vary substantially as a function of ethnic background, such that individuals of Asian descent are more likely to carry the minor (Asp40) allele. The objective of this study is to test the naltrexone pharmacogenetic effects of the Asn40Asp SNP in a sample of Asian Americans. This study consists of a double-blinded, randomized, placebo-controlled laboratory trial of naltrexone. Participants (n=35, 10 females; 13 Asn40Asn and 22 Asp40 carriers) were non-treatment-seeking heavy drinkers recruited from the community. After taking naltrexone or placebo, participants completed an intravenous alcohol administration session. The primary outcome measures were subjective intoxication and alcohol craving. Results suggested that Asp40 carriers experienced greater alcohol-induced sedation, subjective intoxication, and lower alcohol craving on naltrexone, as compared to placebo, and to Asn40 homozygotes. There results were maintained when controlling for ALDH2 (rs671) and ADH1B (rs1229984) markers and when examining the three levels of OPRM1 genotype, thereby supporting an OPRM1 gene dose response. These findings provide a much-needed extension of previous studies of naltrexone pharmacogenetics to individuals of Asian descent, an ethnic group more likely to express the minor allele putatively associated with improved biobehavioral and clinical response to this medication. These findings help further delineate the biobehavioral mechanisms of naltrexone and its pharmacogenetics.

Intramuscular extended-release naltrexone: current evidence

Extended-release naltrexone (XR-NTX; Vivitrol), developed to address poor adherence in addictive disorders, is approved for use in alcohol and opioid-dependence disorders. In alcohol-dependent adults with ≥ 4-day initial abstinence, XR-NTX increased initial and 6-month abstinence. An fMRI study found that XR-NTX attenuated the salience of alcohol visual and olfactory cues in the absence of alcohol, and post hoc analyses demonstrated efficacy even during high cue-exposure holiday periods. Safety and tolerability have generally been good, without adverse hepatic impact or intractable acute pain management. XR-NTX use appears feasible in primary care and public systems, and retrospective claims analyses have found cost savings and decreased intensive service utilization relative to oral agents. In opioid dependence, following detoxification, XR-NTX shows efficacy for maintaining abstinence, improving retention, decreasing craving, and preventing relapse. Trials are also exploring its use for the treatment of stimulant dependence. XR-NTX appears compatible with counseling and self-help attendance. While more research is needed, current findings suggest that a formulation of naltrexone that was sought beginning over three decades ago is fulfilling its promise as an extended-release pharmacotherapeutic.

Medical treatment of alcohol dependence: a systematic review

OBJECTIVE

To summarize published data on pharmacologic treatments for alcohol dependence alone and in combination with brief psychosocial therapies that may be feasible for primary care and specialty medical settings.

METHODS

We conducted electronic searches of published original research articles and reviews in MEDLINE, SCOPUS, CINAHL, Embase, and PsychINFO. In addition, hand searches of reference lists of review articles, supplemental searches of internet references and contacts with experts in the field were conducted. Randomized controlled studies published between January 1960 and August 2010 that met our inclusion/exclusion criteria were included.

RESULTS

A total of 85 studies, representing 18,937 subjects, met our criteria for inclusion. The evidence base for oral naltrexone (6% more days abstinent than placebo in the largest study) and topiramate (prescribed off-label) (e.g., 26.2% more days abstinent than placebo in a recent study) is positive but modest. Acamprosate shows modest efficacy with recently abstinent patients, with European studies showing better results than U.S. ones. The evidence-base for disulfiram is equivocal. Depot naltrexone shows efficacy (25% greater reduction in rate of heavy drinking vs. placebo, in one of the largest studies) in a limited number of studies. Some studies suggest that patients do better with extensive psychosocial treatments added to medications while others show that brief support can be equally effective.

CONCLUSIONS

Although treatment effects are modest, medications for alcohol dependence, in conjunction with either brief support or more extensive psychosocial therapy, can be effective in primary and specialty care medical settings.

HIV, alcohol dependence, and the criminal justice system: a review and call for evidence-based treatment for released prisoners

BACKGROUND

People with both HIV and alcohol use disorders (AUDs) are disproportionately concentrated within the U.S. criminal justice system; approximately one-quarter of all people with HIV cycle through the system each year. HIV-infected prisoners with AUDs face many obstacles as they transition back to the community. Specifically, although they have impressive HIV treatment outcomes during the period of incarceration while they are free from alcohol; upon [corrected] release, however, they face inordinate challenges including relapse to alcohol use resulting in significant morbidity and mortality.

OBJECTIVE

To review the existing literature regarding the relationship of HIV and treatment for AUDs within the criminal justice system in an effort to determine "best practices" that might effectively result in improved treatment of HIV and AUDs for released prisoners.

METHODS

PubMed, PsychInfo and Medline were queried for articles published in English from 1990 to 2009. Selected references from primary articles were also examined.

RESULTS

Randomized controlled trials affirm the role of pharmacotherapy using naltrexone (NTX) as the therapeutic option conferring the best treatment outcome for AUDs in community settings. Absent from these trials were inclusion of released prisoners or HIV-infected individuals. Relapse to alcohol abuse among HIV-infected prisoners is associated with reduced retention in care, poor adherence to antiretroviral therapy with consequential poor HIV treatment outcomes and higher levels of HIV risk behaviors.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Untreated alcohol dependence, particularly for released HIV-infected prisoners, has negative consequences both for the individual and society and requires a concentrated effort and rethinking of our existing approaches for this vulnerable population.

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.