Nalmefene for the management of alcohol dependence: review on its pharmacology, mechanism of action and meta-analysis on its clinical efficacy

Prazosin and cyproheptadine in combination in the treatment of alcohol use disorder: A randomized, double-blind, placebo-controlled trial

BACKGROUND AND AIMS

Pre-clinical studies suggest that the simultaneous blockade of the α1b and 5HT2A receptors may be effective in reducing alcohol consumption. This study aimed to assess the efficacy and safety of prazosin (α1b blocker) and cyproheptadine (5HT2A blocker) combination in decreasing total alcohol consumption (TAC) in alcohol use disorder (AUD).

DESIGN, SETTING AND PARTICIPANTS

This was a double-blind, parallel group, placebo-controlled, Phase 2, randomized clinical trial conducted in 32 addiction treatment centres in France. A total of 108 men and 46 women with severe AUD took part.

INTERVENTION

Participants were randomly assigned to one of the following 3-month treatments: (1) low-dose group (LDG) receiving 8 mg cyproheptadine and 5 mg prazosin extended-release (ER) formulation daily; (2) high-dose group (HDG) receiving 12 mg cyproheptadine and 10 mg prazosin ER daily; and (3) placebo group (PG) receiving placebo of cyproheptadine and prazosin ER. A total of 154 patients were randomized: 54 in the PG, 54 in the LDG and 46 in the HDG.

MEASUREMENTS

The primary outcome was TAC change from baseline to month 3.

FINDINGS

A significant main treatment effect in the change in TAC was found in the intent-to-treat population (P = 0.039). The HDG and LDG showed a benefit in the change in TAC from baseline to month 3 compared with PG: -23.6 g/day, P = 0.016, Cohen's d = -0.44; -18.4 g/day, P = 0.048 (Bonferroni correction P < 0.025), Cohen's d = -0.36. In a subgroup of very high-risk drinking-level participants (> 100 g/day of pure alcohol for men and > 60 g/day for women), the difference between the HDG and the PG in the primary outcome was -29.8 g/day (P = 0.031, Cohen's d = -0.51). The high and low doses were well-tolerated with a similar safety profile.

CONCLUSIONS

A randomized controlled trial of treatment of severe alcohol use disorder with a cyproheptadine-prazosin combination for 3 months reduced drinking by more than 23 g per day compared with placebo. A higher dose combination was associated with a larger magnitude of drinking reduction than a lower dose combination while showing similar safety profile.

Brief intervention for chronic liver disease patients with alcohol use disorder in a hepatology outpatient unit: Effects and limitations

AIM

It is not uncommon to encounter outpatients in the hepatology department with harmful alcohol habits. When treating such chronic liver disease (CLD) patients, an adequate intervention method for harm reduction of alcohol use, such as brief intervention (BI) or BI and nalmefene, should be considered. This study aimed to elucidate the clinical effectiveness of BI for CLD patients affected by harmful alcohol use.

METHODS

From June 2021 to 2023, 123 Japanese CLD outpatients (hepatitis B virus : hepatitis C virus : alcoholic liver disease : others = 32:18:42:31) with an Alcohol Use Disorders Identification Test (AUDIT) score of ≥8 at the initial interview and a repeat interview with AUDIT 9 months later were enrolled. Clinical features related to patient behavior following the initial AUDIT interview were retrospectively evaluated, and compared between patients without and with BI treatment.

RESULTS

For the non-BI and BI groups, baseline AUDIT score (median 10 [interquartile range (IQR) 9-13] vs. 12 [IQR 10-17], p = 0.016) and relative change in AUDIT score (median 0 [IQR -3 to 2] vs. -3 [IQR -7 to 0], p < 0.01) showed significant differences, whereas there was no significant difference between the groups for AUDIT score at the time of the second interview (p = 0.156). Following BI, significant improvements were observed for items 1, 2, 3, 4, 5, 8, and 10 of AUDIT (each p < 0.05).

CONCLUSION

Patients with an alcohol use disorder as well as those with alcohol dependency who received BI showed a significant decline in AUDIT score, although the score of the follow-up AUDIT indicated continued alcohol use disorder. In addition to BI, medication with nalmefene should be considered, based on individual factors.

AUD in perspective

Alcohol is a major cause of pre-mature death and individual suffering worldwide, and the importance of diagnosing and treating AUD cannot be overstated. Given the global burden and the high attributable factor of alcohol in a vast number of diseases, the need for additional interventions and the development of new medicines is considered a priority by the World Health Organization (WHO). As of today, AUD is severely under-treated with a treatment gap nearing 90%, strikingly higher than that for other psychiatric disorders. Patients often seek treatment late in the progress of the disease and even among those who seek treatment only a minority receive medication, mirroring the still-prevailing stigma of the disease, and a lack of access to effective treatments, as well as a reluctance to total abstinence. To increase adherence, treatment goals should focus not only on maintaining abstinence, but also on harm reduction and psychosocial functioning. A personalised approach to AUD treatment, with a holistic view, and tailored therapy has the potential to improve AUD treatment outcomes by targeting the heterogeneity in genetics and pathophysiology, as well as reason for, and reaction to drinking. Also, the psychiatric co-morbidity rates are high in AUD and dual diagnosis can worsen symptoms and influence treatment response and should be considered in the treatment strategies.

Repurposing drugs for treatment of alcohol use disorder

Repurposing drugs for the treatment of alcohol dependence involves the use of drugs that were initially developed for other conditions, but have shown promise in reducing alcohol use or preventing relapse. This approach can offer a more cost-effective and time-efficient alternative to developing new drugs from scratch. Currently approved medications for alcohol use disorder (AUD) include acamprosate, disulfiram, naltrexone, nalmefene, baclofen, and sodium oxybate. Acamprosate was developed specifically for AUD, while disulfiram's alcohol-deterrent effects were discovered incidentally. Naltrexone and nalmefene were originally approved for opioids but found secondary applications in AUD. Baclofen and sodium oxybate were repurposed from neurological conditions. Other drugs show promise. Topiramate and zonisamide, anticonvulsants, demonstrate efficacy in reducing alcohol consumption. Another anticonvulsant, gabapentin has been disappointing overall, except in cases involving alcohol withdrawal symptoms. Varenicline, a nicotinic receptor agonist, benefits individuals with less severe AUD or concurrent nicotine use. Ondansetron, a 5-HT3 antagonist, has potential for early-onset AUD, especially when combined with naltrexone. Antipsychotic drugs like aripiprazole and quetiapine have limited efficacy. Further investigation is needed for potential repurposing of α1 adrenergic receptor antagonists prazosin and doxazosin, glucocorticoid receptor antagonist mifepristone, the phosphodiesterase inhibitor Ibudilast, the cysteine prodrug N-acetylcysteine, and the OX1R and OX2R blocker Suvorexant. This review supports repurposing drugs as an effective strategy for expanding treatment options for AUD.

Economic evaluations of alcohol pharmacotherapy: Systematic review of economic evaluations of pharmacotherapy for the treatment of alcohol use disorder

OBJECTIVE

Alcohol use disorders confer a significant burden of disease and economic cost worldwide. However, the utilisation of pharmacotherapies to manage alcohol use disorder is poor. We aimed to conduct a systematic review of economic evaluation studies of alcohol use disorder pharmacotherapies.

METHODS

A search was conducted in Embase, Medline, CINAHL, PsychINFO and EconLit (August 2019, updated September 2022). Full economic evaluations using pharmacotherapy to treat alcohol use disorders were included. Included studies were stratified by medication and summarised descriptively. The Consensus on Health Economic Criteria list was used to assess the methodological quality.

RESULTS

A total of 1139 studies were retrieved, of which 15 met the inclusion criteria. All studies were conducted in high-income countries. Four studies analysed nalmefene, four studies assessed acamprosate, three for naltrexone and four for stand-alone and/or combinations of naltrexone and acamprosate. There were 21 interventions synthesised from 15 studies as some studies evaluated multiple interventions and comparators. More than half of the included studies (73%) reported pharmacotherapy as dominant (less costly and more effective than comparators). From healthcare payer perspectives, five studies found that pharmacotherapy added to psychosocial support was dominant or cost-effective, accruing additional benefits at a higher cost but under accepted willingness to pay thresholds. Three analyses from a societal perspective found pharmacotherapy added to psychosocial support was a dominant or cost-effective strategy. Quality scores ranged from 63% to 95%.

CONCLUSION

Pharmacotherapy added to psychosocial support was cost-effective from both healthcare and societal perspectives, emphasising an increased role for pharmacotherapy to reduce the burden of alcohol use disorders.

Pharmacological Treatment of Alcohol use Disorder in Patients with Psychotic Disorders: A Systematic Review

BACKGROUND

Patients with psychotic disorders (PD) often have comorbid alcohol use disorder (AUD), which is typically treated pharmacologically. Up till now, no systematic review has examined the effectiveness and safety of AUD treatment in PD patients.

OBJECTIVES

This study aimed to systematically review the literature on (1) the effects of pharmacological treatments for AUD on drinking outcomes, (2) the side effects of the drugs, and (3) the effects of polypharmacy in patients with comorbid AUD and PD.

METHODS

Bibliographic searches were conducted in MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and PsycINFO. At least two reviewers extracted the data, assessed the risk of bias, and performed the qualitative synthesis of the collected evidence.

RESULTS

Twelve eligible studies were identified, half being randomized controlled trials (RCTs). Three studies examined disulfiram, nine naltrexone, two acamprosate, and one nalmefene by comparing the effects of treatment to placebo, baseline, or pharmacological agents. Disulfiram and naltrexone were shown to reduce alcohol intake. Regarding acamprosate, the findings were mixed. Nalmefene decreased alcohol intake. All pharmacological agents appeared safe to use as AUD monotherapy, but cardiac events were reported when combining naltrexone and disulfiram. Nine studies had a high risk of bias, and three had some other concerns.

CONCLUSION

The studies provide tentative support for the use of naltrexone and disulfiram in this population, although combinations of pharmacological AUD treatments and other polypharmacy remain unexplored. The studies had high adherence rates that are hardly replicable in real-world settings. Thus, the findings should be confirmed in larger high quality efficacy and effectiveness RCTs with longer follow-ups.

Management of Patients After Treatment of Severe Alcohol-associated Hepatitis

Alcohol-associated liver disease is the leading indication for hospitalization among patients with chronic liver disease. Rates of hospitalization for alcohol-associated hepatitis have been rising over the last 2 decades. Patients with alcohol-associated hepatitis carry significant morbidity and mortality, but there is a lack of standardized postdischarge management strategies to care for this challenging group of patients. Patients warrant management of not only their liver disease but also their alcohol use disorder. In this review, we will discuss outpatient management strategies for patients who were recently hospitalized and discharged for alcohol-associated hepatitis. We will discuss short management of their liver disease, long-term follow-up, and review-available treatment options for alcohol use disorder and challenges associated with pursuing treatment for alcohol use disorder.

Low-dose nalmefene pretreatment reduces etomidate-induced myoclonus: A randomized, double-blind controlled trial

BACKGROUND

This study compared the effectiveness of nalmefene and fentanyl in reducing the incidence and severity of etomidate-induced myoclonus.

METHODS

One hundred fifty patients were randomized to receive 0.25ug/kg of nalmefene, 1ug/kg of fentanyl, or the same volume of normal saline 3 minutes prior to etomidate-induced anesthesia. The primary observational indexes were the severity level and incidence of etomidate-induced myoclonus, and the secondary observational index included blood pressure, heart rate, and the incidence of adverse effects from anesthesia induction to resuscitation, such as cough, chest wall rigidity, dizziness, nausea, pain after awakening, and intraoperative awareness.

RESULTS

The incidence of myoclonus was significantly lower in the nalmefene group (8.0%) than in the fentanyl group (32.0%) (P = .003) and in the normal saline group (72.0%) (P = .000). The severity level of myoclonus in the nalmefene group was significantly lower than the fentanyl group (P = .001) and normal saline group (P = .000). Meanwhile, the incidences of cough and chest wall rigidity during anesthesia induction were significantly lower in the nalmefene group compared with the fentanyl group (P = .003, P = .027). There were no statistically significant differences in heart rate and mean arterial pressure among the 3 gruops (P > .05). There was no difference in the incidence of adverse effects among the 3 groups during recovery from anesthesia (P > .05).

CONCLUSION

Intravenous injection of 0.25ug/kg of nalmefene 3 minutes prior to etomidate is more effective in preventing etomidate-induced myoclonus during general anesthesia than 1ug/kg of fentanyl.

Nalmefene combined noninvasive positive-pressure ventilation in Chinese patients with chronic obstructive pulmonary disease coupled with type II respiratory failure: A meta-analysis

BACKGROUND

Nalmefene is an opioid system modulator with antagonist activity at the μ and δ receptors and partial agonist activity at the κ receptor. Previous studies have suggested that nalmefene could improve respiratory function in patients with chronic obstructive pulmonary disease (COPD). However, there is no comprehensive systematic review published regarding the clinical efficacy of nalmefene.

METHODS

We explored the following electronic bibliographic databases: EMBASE, Web of Science, PubMed, Wanfang, and Chinese national knowledge infrastructure. To collect data from randomized controlled trials on the therapy of COPD coupled with type II respiratory failure and nalmefene + noninvasive ventilator treatment. The retrieved articles were screened to determine the final inclusion criteria and to extract relevant data, such as the clinical efficacy rate, pulmonary function, blood gas analysis, and adverse reactions. In our study, we used relative risk and weighted mean deviation, as well as a 95% confidence interval for describing nalmefene effectiveness and safety while treating COPD with type II respiratory failure.

RESULTS

The outcomes of the meta-analysis demonstrated that the clinical efficacy rate of the nalmefene + noninvasive ventilation group was higher than that of the naloxone + noninvasive ventilation and noninvasive ventilation groups. Moreover, the improvement indices of pH value, partial pressure and saturation of blood oxygen, partial pressure of carbon dioxide, and pulmonary function of the nalmefene + noninvasive ventilation group were better than those of the noninvasive ventilation group, and there was no increase in the occurrence of adverse drug reactions.

CONCLUSION

Nalmefene combined with noninvasive ventilation can significantly improve the blood gas index and lung function in patients with COPD combined with type II respiratory failure.

Sodium Oxybate for Alcohol Dependence: A Network Meta-Regression Analysis Considering Population Severity at Baseline and Treatment Duration

AIMS

The estimated effect of sodium oxybate (SMO) in the treatment of alcohol dependence is heterogeneous. Population severity and treatment duration have been identified as potential effect modifiers. Population severity distinguishes heavy drinking patients with <14 days of abstinence before treatment initiation (high-severity population) from other patients (mild-severity population). Treatment duration reflects the planned treatment duration. This study aimed to systematically investigate the effect of these potential effect moderators on SMO efficacy in alcohol-dependent patients.

METHODS

Network meta-regression allows for testing potential effect modifiers. It was selected to investigate the effect of the above factors on SMO efficacy defined as continuous abstinence (abstinence rate) and the percentage of days abstinent (PDA). Randomized controlled trials for alcohol dependence with at least one SMO group conducted in high-severity and mild-severity populations were assigned to a high-severity and mild-severity group of studies, respectively.

RESULTS

Eight studies (1082 patients) were retained: four in the high-severity group and four in the mild-severity group. The high-severity group was associated with larger SMO effect sizes than the mild-severity group: abstinence rate risk ratio (RR) 3.16, P = 0.004; PDA +26.9%, P < 0.001. For PDA, longer treatment duration was associated with larger SMO effect size: +11.3% per extra month, P < 0.001. In the high-severity group, SMO showed benefit: abstinence rate RR 2.91, P = 0.03; PDA +16.9%, P < 0.001. In the mild-severity group, SMO showed benefit only in PDA for longer treatment duration: +23.9%, P < 0.001.

CONCLUSIONS

In the retained studies with alcohol-dependent patients, high-severity population and longer treatment duration were associated with larger SMO effect sizes.

Inhibitory Effects of a Novel μ-Opioid Receptor Nonpeptide Antagonist, UD-030, on Morphine-Induced Conditioned Place Preference

Although opioids are widely used to treat moderate to severe pain, opioid addiction and the opioid overdose epidemic are becoming more serious. Although opioid receptor antagonists/partial agonists, such as naltrexone and buprenorphine, have relatively low selectivity for the μ-opioid receptor (MOP), they have been used for the management of opioid use disorder. The utility of highly selective MOP antagonists remains to be evaluated. Here, we biologically and pharmacologically evaluated a novel nonpeptide ligand, UD-030, as a selective MOP antagonist. UD-030 had more than 100-fold higher binding affinity for the human MOP (K_i = 3.1 nM) than for δ-opioid, κ-opioid, and nociceptin receptors (K_i = 1800, 460, and 1800 nM, respectively) in competitive binding assays. The [³⁵S]-GTPγS binding assay showed that UD-030 acts as a selective MOP full antagonist. The oral administration of UD-030 dose-dependently suppressed the acquisition and expression of morphine-induced conditioned place preference in C57BL/6J mice, and its effects were comparable to naltrexone. These results indicate the UD-030 may be a new candidate for the treatment of opioid use disorder, with characteristics that differ from traditional medications that are in clinical use.

Clinical features of patients with chronic liver disease in Japan related to alcohol use: Nationwide examination using alcohol use disorders identification test

AIM

Patients often do not respond truthfully to physicians' interviews concerning alcohol. Few reports regarding the level of alcohol dependence in patients with chronic liver disease (CLD) have been presented. This study aimed to elucidate severity distribution in patients with CLD using the alcohol use disorders identification test (AUDIT).

METHODS

From March to June 2022, 2034 Japanese outpatients with CLD, including 415 cases associated with hepatitis C virus, 436 with hepatitis B virus, 173 with alcohol-related liver disease (ARLD), and 1010 with other factors, were interviewed using AUDIT. Clinical features related to alcohol use in these patients were then retrospectively evaluated.

RESULTS

In all patients, an AUDIT score 8-14 (harmful use) was noted in 5.8% of hepatitis C virus, 8.9% of hepatitis B virus, 24.3% of ARLD, and 4.4% of other groups, respectively (P < 0.001), while a score ≥15 (dependency) was noted in 3.4%, 3.0%, 27.7%, and 1.9%, respectively (P < 0.001). When the country was divided into regions, the percentages remained similar. Comparisons between patients with and without an AUDIT score ≥8 (n = 1412), performed after exclusion of those without related data (n = 622), showed no significant differences for hepatic reserve function, while those with harmful alcohol use were significantly younger (66 vs. 70 years, P = 0.006) and had a larger percentage of men (80.4% vs. 45.1%, P < 0.001).

CONCLUSION

Harmful alcohol and alcohol dependency were observed in approximately 10% of patients with viral or non-viral CLD, after excluding patients with ARLD. Assessment of alcohol intake by use of the AUDIT questionnaire as well as adequate intervention should be considered necessary.

Alcohol Use Disorder: Neurobiology and Therapeutics

Alcohol use disorder (AUD) encompasses the dysregulation of multiple brain circuits involved in executive function leading to excessive consumption of alcohol, despite negative health and social consequences and feelings of withdrawal when access to alcohol is prevented. Ethanol exerts its toxicity through changes to multiple neurotransmitter systems, including serotonin, dopamine, gamma-aminobutyric acid, glutamate, acetylcholine, and opioid systems. These neurotransmitter imbalances result in dysregulation of brain circuits responsible for reward, motivation, decision making, affect, and the stress response. Despite serious health and psychosocial consequences, this disorder still remains one of the leading causes of death globally. Treatment options include both psychological and pharmacological interventions, which are aimed at reducing alcohol consumption and/or promoting abstinence while also addressing dysfunctional behaviours and impaired functioning. However, stigma and social barriers to accessing care continue to impact many individuals. AUD treatment should focus not only on restoring the physiological and neurological impairment directly caused by alcohol toxicity but also on addressing psychosocial factors associated with AUD that often prevent access to treatment. This review summarizes the impact of alcohol toxicity on brain neurocircuitry in the context of AUD and discusses pharmacological and non-pharmacological therapies currently available to treat this addiction disorder.

Clinical moderators of response to nalmefene in a randomized-controlled trial for alcohol dependence: An exploratory analysis

BACKGROUND

Nalmefene is the only medication marketed to reduce the consumption of alcohol in patients with alcohol dependence, but it remains unclear which patients could most benefit from it. This study aimed to identify clinical moderators that affect treatment response to nalmefene in patients with alcohol dependence.

METHODS

In a multicenter, randomized, controlled, double-blind, phase 3 study of nalmefene on Japanese patients with alcohol dependence, the relationship between the reduction of heavy drinking days (HDD) and total alcohol consumption (TAC) at 12 and 24 weeks of treatment and baseline variables of the participants were analyzed in a linear regression and multiple adjusted analysis.

RESULTS

Age < 65, no family history of problem drinking, age at onset of problem drinking ≥ 25, and not currently smoking were possible positive moderators. Nalmefene showed a significant HDD reduction in patients with age < 65 or no family history of problem drinking, and a significant TAC reduction in patients with age at onset of problem drinking ≥ 25 or who were not currently smoking. After multiple adjusted analyses, age < 65 (p = .028), no family history of problem drinking (p = .047), and age at onset of problem drinking ≥ 25 (p = .030) were statistically significant. Not currently smoking (p = .071) was marginally significant. In combination, these moderators indicated synergistic effects.

CONCLUSIONS

Alcohol-dependent patients with favorable prognostic factors such as non-smoking status, no family history of problem drinking, and a late-onset of problem drinking selectively benefit from nalmefene. Further research is needed to validate these exploratory results.

Sex differences and the lack of effects of chemogenetic manipulation of pro-opiomelanocortin (POMC) neurons on alcohol consumption in male and female mice

The endogenous opioid system has been implicated in the rewarding and reinforcing effects of alcohol. Pro-opiomelanocortin (POMC) neurons located within the arcuate nucleus of the hypothalamus (ArcN) secrete multiple peptides associated with alcohol consumption, including β-endorphin (β-END), α-melanocyte stimulating hormone (α-MSH), and adrenocorticotropic hormone (ACTH). In this study, we utilized chemogenetics to bidirectionally modulate ArcN POMC neurons to determine their role in alcohol and saccharin consumption and regional levels of POMC-derived peptides. Male and female POMC-cre mice were infused with viral vectors designed for cre-dependent expression of either excitatory and inhibitory DREADDs or a control vector into the ArcN. Following recovery, animals were allowed to consume alcohol or saccharin using the drinking-in-the-dark (DID) paradigm of binge-like intake for 4 consecutive days. Prior to the final test session, animals were injected with clozapine-N-oxide (2.5 mg/kg, i.p.) for DREADD activation. Following the last DID session, animals were euthanized and the ArcN, VTA, amygdala and NAc were dissected and assessed for POMC peptide expression utilizing western blotting. We found that female mice consumed more alcohol than males during DID sessions 2-4, and that chemogenetic activation had no effect on alcohol or saccharin consumption in either sex. We found that β-END expression within the ArcN positively correlated with alcohol consumption. Given the molecular and functional heterogeneity of ArcN POMC neurons, future studies are needed to assess the effects of modulation of specific subpopulations of these neurons within the ArcN on consumption of rewarding substances such as alcohol and saccharin.

Peptide Kappa Opioid Receptor Ligands and Their Potential for Drug Development

Ligands for kappa opioid receptors (KOR) have potential uses as non-addictive analgesics and for the treatment of pruritus, mood disorders, and substance abuse. These areas continue to have major unmet medical needs. Significant advances have been made in recent years in the preclinical development of novel opioid peptides, notably ones with structural features that inherently impart stability to proteases. Following a brief discussion of the potential therapeutic applications of KOR agonists and antagonists, this review focuses on two series of novel opioid peptides, all-D-amino acid tetrapeptides as peripherally selective KOR agonists for the treatment of pain and pruritus without centrally mediated side effects, and macrocyclic tetrapeptides based on CJ-15,208 that can exhibit different opioid profiles with potential applications such as analgesics and treatments for substance abuse.

Alcohol and the Brain

Alcohol works on the brain to produce its desired effects, e.g., sociability and intoxication, and hence the brain is an important organ for exploring subsequent harms. These come in many different forms such as the consequences of damage during intoxication, e.g., from falls and fights, damage from withdrawal, damage from the toxicity of alcohol and its metabolites and altered brain structure and function with implications for behavioral processes such as craving and addiction. On top of that are peripheral factors that compound brain damage such as poor diet, vitamin deficiencies leading to Wernicke-Korsakoff syndrome. Prenatal alcohol exposure can also have a profound impact on brain development and lead to irremediable changes of fetal alcohol syndrome. This chapter briefly reviews aspects of these with a particular focus on recent brain imaging results. Cardiovascular effects of alcohol that lead to brain pathology are not covered as they are dealt with elsewhere in the volume.

Treating alcohol dependence with an abuse and misuse deterrent formulation of sodium oxybate: Results of a randomised, double-blind, placebo-controlled study

Sodium oxybate (SMO) has been approved in Italy and Austria for the maintenance of abstinence in alcohol dependent (AD) patients. Although SMO is well tolerated in AD patients, cases of abuse and misuse have been reported outside the therapeutic setting. Here we report on a phase IIb double-blind, randomized, placebo-controlled trial for the maintenance of abstinence in AD patients with a new abuse and misuse deterrent formulation of SMO. A total of 509 AD patients were randomized to 12 weeks of placebo or one of four SMO doses (0.75, 1.25, 1.75 or 2.25 g t.i.d.) followed by a one-week medication-free period. The primary endpoint was the percentage of days abstinent (PDA) at end of treatment. An unexpectedly high placebo response (mean 73%, median 92%) was observed. This probably compromised the demonstration of efficacy in the PDA, but several secondary endpoints showed statistically significant improvements. A post-hoc subgroup analysis based on baseline severity showed no improvements in the mild group, but statistically significant improvements in the severe group: PDA: mean difference +15%, Cohen's d = 0.42; abstinence: risk difference +18%, risk ratio = 2.22. No safety concerns were reported. Although the primary endpoint was not significant in the overall population, several secondary endpoints were significant in the intent-to-treat population and post-hoc results showed that treatment with SMO was associated with a significant improvement in severe AD patients which is consistent with previous findings. New trials are warranted that take baseline severity into consideration.

Baseline severity and the prediction of placebo response in clinical trials for alcohol dependence: A meta-regression analysis to develop an enrichment strategy

BACKGROUND

There is considerable unexplained variability in alcohol abstinence rates (AR) in the placebo groups of randomized controlled trials (RCTs) for alcohol dependence (AD). This is of particular interest because placebo responses correlate negatively with treatment effect size. Recent evidence suggests that the placebo response is lower in very heavy drinkers who show no "spontaneous improvement" prior to treatment initiation (high-severity population) than in a mild-severity population and in studies with longer treatment duration. We systematically investigated the relationship between population severity, treatment duration, and the placebo response in AR to inform a strategy aimed at reducing the placebo response and thereby increasing assay sensitivity in RCTs for AD.

METHODS

We conducted a systematic literature review on placebo-controlled RCTs for AD.We assigned retained RCTs to high- or mild-severity groups of studies based on baseline drinking risk levels and abstinence duration before treatment initiation. We tested the effects of population severity and treatment duration on the placebo response in AR using meta-regression analysis.

RESULTS

Among the 19 retained RCTs (comprising 1996 placebo-treated patients), 11 trials were high-severity and 8 were mild-severity RCTs. The between-study variability in AR was lower in the high-severity than in the mild-severity studies (interquartile range: 7.4% vs. 20.9%). The AR in placebo groups was dependent on population severity (p = 0.004) and treatment duration (p = 0.017) and was lower in the high-severity studies (16.8% at 3 months) than the mild-severity studies (36.7% at 3 months).

CONCLUSIONS

Pharmacological RCTs for AD should select high-severity patients to decrease the magnitude and variability in the placebo effect and and improve the efficiency of drug development efforts for AD.

Systematische Literaturübersicht der Wirksamkeit von Acamprosat, Naltrexon, Disulfiram und Nalmefen zur Trinkmengenreduktion und Aufrechterhaltung der Abstinenz bei Alkoholabhängigkeit

Das Ziel der vorliegenden Übersichtsarbeit ist die systematische Darstellung der aktuellen Evidenz zur Wirksamkeit von Acamprosat, Naltrexon, Disulfiram und Nalmefen für die Aufrechterhaltung der Abstinenz oder Trinkmengenreduktion bei alkoholabhängigen Patient:innen. Bezogen auf den Zeitraum 2005 bis 2020 wurden insgesamt 27 Studien identifiziert, die alle Einschlusskriterien (u. a. RCT, mind. 8 Wochen Behandlungsdauer) erfüllten. Es wurden überwiegend Hinweise zur Wirksamkeit von Nalmefen gefunden. Acamprosat war nicht (zusätzlich) wirksam. Naltrexon trug in kombinierten Interventionen einen zusätzlichen Nutzen bei, dies galt jedoch nicht für die Mehrzahl der Studien. Disulfiram war nicht wirksam darin, einen zusätzlichen Nutzen zur Erhaltung der Abstinenz beizutragen, im Vergleich zu Topiramat, einem Antikonvulsivum, jedoch effektiver. Die Ergebnisse stehen nicht im Einklang mit dem bisher bekannten Forschungsstand, der Acamprosat, Naltrexon und Nalmefen als überwiegend effektiv und sicher einstuft und Disulfiram als mäßig wirksam. Der pharmakologische Interventionsbedarf sollte bei Bestehen alkoholbezogener Probleme exploriert und ggf. erwogen werden, damit diesbezüglich Vorbehalte abgebaut und ein umfassendes und zugleich individuelles Behandlungsangebot geschaffen wird. Hinsichtlich der Trinkmengenreduktion sollten Aspekte der Schadensminderung als Behandlungsziel berücksichtigt werden.

Nalmefene attenuates neural alcohol cue-reactivity in the ventral striatum and subjective alcohol craving in patients with alcohol use disorder

RATIONALE

Alcohol use disorder is a common and devastating mental illness for which satisfactory treatments are still lacking. Nalmefene, as an opioid receptor modulator, could pharmacologically support the reduction of drinking by reducing the (anticipated) rewarding effects of alcohol and expanding the range of treatment options. It has been hypothesized that nalmefene acts via an indirect modulation of the mesolimbic reward system. So far, only a few imaging findings on the neuronal response to nalmefene are available.

OBJECTIVES

We tested the effect of a single dose of 18 mg nalmefene on neuronal cue-reactivity in the ventral and dorsal striatum and subjective craving.

METHODS

Eighteen non-treatment-seeking participants with alcohol use disorder (67% male, M = 50.3 ± 13.9 years) with a current high-risk drinking level (M = 76.9 ± 52 g of pure alcohol per day) were investigated using a cue-reactivity task during functional magnetic resonance imaging (fMRI) in a double-blind, placebo-controlled, cross-over study/design. In addition, self-reported craving was assessed before and after exposure to alcohol cues.

RESULTS

An a priori defined region of interest (ROI) analysis of fMRI data from 15 participants revealed that nalmefene reduced alcohol cue-reactivity in the ventral, but not the dorsal striatum. Additionally, the subjective craving was significantly reduced after the cue-reactivity task under nalmefene compared to placebo.

CONCLUSION

In the present study, reduced craving and cue-reactivity to alcohol stimuli in the ventral striatum by nalmefene indicates a potential anti-craving effect of this drug via attenuation of neural alcohol cue-reactivity.

Association of the OPRM1 A118G polymorphism and Pavlovian-to-instrumental transfer: Clinical relevance for alcohol dependence

BACKGROUND

Pavlovian-to-instrumental transfer (PIT) quantifies the extent to which a stimulus that has been associated with reward or punishment alters operant behaviour. In alcohol dependence (AD), the PIT effect serves as a paradigmatic model of cue-induced relapse. Preclinical studies have suggested a critical role of the opioid system in modulating Pavlovian-instrumental interactions. The A118G polymorphism of the OPRM1 gene affects opioid receptor availability and function. Furthermore, this polymorphism interacts with cue-induced approach behaviour and is a potential biomarker for pharmacological treatment response in AD. In this study, we tested whether the OPRM1 polymorphism is associated with the PIT effect and relapse in AD.

METHODS

Using a PIT task, we examined three independent samples: young healthy subjects (N = 161), detoxified alcohol-dependent patients (N = 186) and age-matched healthy controls (N = 105). We used data from a larger study designed to assess the role of learning mechanisms in the development and maintenance of AD. Subjects were genotyped for the A118G (rs1799971) polymorphism of the OPRM1 gene. Relapse was assessed after three months.

RESULTS

In all three samples, participants with the minor OPRM1 G-Allele (G+ carriers) showed increased expression of the PIT effect in the absence of learning differences. Relapse was not associated with the OPRM1 polymorphism. Instead, G+ carriers displaying increased PIT effects were particularly prone to relapse.

CONCLUSION

These results support a role for the opioid system in incentive salience motivation. Furthermore, they inform a mechanistic model of aberrant salience processing and are in line with the pharmacological potential of opioid receptor targets in the treatment of AD.

Nalmefene alleviates the neuroimmune response to repeated binge-like ethanol exposure: A TSPO PET imaging study in adolescent rats

A large body of preclinical research has shown that neuroimmunity plays a key role in the deleterious effects of alcohol (ethanol) to the brain. Translational imaging techniques are needed to monitor the efficacy of strategies to prevent or mitigate neuroinflammation and alleviate ethanol-induced neurotoxicity. Opioid receptor antagonists such as nalmefene are antagonists of the toll-like receptor 4, which may block the proinflammatory signaling cascade induced by ethanol at this specific target. Male adolescent rats received a validated protocol of ethanol injection (i.p, 3 g/kg daily for two consecutive days followed by two resting days) during 14 days. Positron emission tomography (PET) imaging with the translocator protein 18 kDa (TSPO) radioligand [¹⁸ F]DPA-714 was performed at day-15. Toxicity induced by repeated binge-like ethanol exposure (71% mortality) was drastically reduced by nalmefene pretreatment (0.4 mg/kg, 14% mortality). No mortality was observed in animals that received vehicle (control) or nalmefene alone. Compared with control animals (n = 10), a significant 2.8-fold to 4.6-fold increase in the volume of distribution (V_T ) of [¹⁸ F]DPA-714 was observed among brain regions in animals exposed to ethanol only (n = 9). Pretreatment with nalmefene significantly alleviated the neuroimmune response to ethanol exposure in all brain regions (1.2-fold to 2.5-fold increase in V_T ; n = 5). Nalmefene alone (n = 6) did not impact [¹⁸ F]DPA-714 V_T compared with the control group. Nalmefene may protect against the neuroinflammatory response and overall toxicity associated with binge drinking. [¹⁸ F]DPA-714 PET imaging can be used to noninvasively address the neuroimmune impact of ethanol exposure and its modulation by pharmacological strategies in vivo, with translational perspectives.

New approved and emerging pharmacological approaches to alcohol use disorder: a review of clinical studies

introduction: The number of medications approved for AUD is small and they generally have limited efficacy. We need new pharmacotherapies for the management of AUD.Areas covered: In this review, the authors aim to synthesise literature for new approved and emerging pharmacotherapies for AUD. Recently approved medications include nalmefene, which was approved in Europe and Australia for the purposes of controlled drinking. Baclofen has also been approved in France but not in other countries. Off label medications including topiramate and gabapentin have received significant attention with multiple RCTs and meta-analyses and have widespread use in several countries including the USA. Several novel medications have emerged over the last decade but further work is required to determine their efficacy and safety for the widespread management of AUD.Expert opinion: Despite significant advances in our understanding of the neurobiological basis of factors that contribute to the development and maintenance of AUD, there have been few new AUD medications approved for almost 20 years. There are many challenges to the development and introduction of new pharmacotherapies for AUD. Strategies for improving the translational pipeline include drug repurposing and utilisation of human acute laboratory models.

Is R(+)-Baclofen the best option for the future of Baclofen in alcohol dependence pharmacotherapy? Insights from the preclinical side

For several decades, studies conducted to evaluate the efficacy of RS(±)-Baclofen in the treatment of alcohol dependence yielded contrasting results. Human and animal studies recently questioned the use of the racemic drug in patients since a potential important role of the different enantiomers has been revealed with an efficacy thought to reside with the active R(+)-enantiomer. Here we conducted experiments in the postdependent rat model of alcohol dependence to compare the efficacy of R(+)-Baclofen or S(-)-Baclofen to that of RS(±)-Baclofen on ethanol intake, seeking, and relapse. R(+)-Baclofen was more effective than RS(±)-Baclofen in reducing ethanol intake and seeking during acute withdrawal and during relapse after abstinence. We also used an original population approach in order to identify drug responders. We found a significant proportion of responders to S(-)-Baclofen and RS(±)-Baclofen, displaying an increase in ethanol intake, and this increasing effect on alcohol intake was not seen in the R(+)-Baclofen group. At an intermediate dose of R(+)-Baclofen, devoid of any motor side effects, we identified a very large proportion of responders (75%) with a large decrease in ethanol intake (90% decrease). Finally, the response to RS(±)-Baclofen on ethanol intake was correlated to plasma level of Baclofen. R(+)-Baclofen and RS(±)-Baclofen were effective in reducing sucrose intake. Our study has important clinical implication since it suggests that the wide variability in the therapeutic responses of patients to RS(±)-Baclofen may come from the sensitivity to the R(+)-Baclofen but also to the one of the S(-)-Baclofen that can promote an increase in ethanol intake.

Reduced drinking and harm reduction in the treatment of alcohol use disorders

Purpose

The purpose of this paper is to give an overview of the scientific evidence for reduced drinking in alcohol use disorders. While the aim of alcohol use disorders (AUD) treatment usually focuses on abstinence, only a minority of individuals with AUD enter treatment. Lack of alternative treatment goals, including reduced drinking instead of abstinence, have been identified as a potential barrier for treatment entry. Epidemiological and treatment outcome studies reveal that a large proportion of individuals with AUD are able to substantially reduce their alcohol intake for a prolonged duration of time.

Design/methodology/approach

A narrative review of the literature on prevalence rates and health effects as well as evidence-based approaches fostering reduced drinking in individuals with AUD is presented.

Findings

Reduced drinking is associated with improvements in both morbidity and mortality. Research has identified evidence-based psychosocial and pharmacological treatment approaches; however, implementation is still scarce.

Originality/value

Target groups for interventions fostering drinking reduction instead of abstinence are defined and desiderata for further research are outlined.

Long-term safety and efficacy of nalmefene in Japanese patients with alcohol dependence

AIM

The safety and efficacy of nalmefene in Japanese patients with high or very high World Health Organization drinking risk level of alcohol dependence were assessed in a multicenter, randomized, double-blind, placebo-controlled, phase 3 (lead-in) study. Here, the long-term safety and efficacy of nalmefene in an open-label extension of the lead-in study are presented.

METHODS

Patients who completed the 24-week lead-in study were eligible for the extension study, where they were treated with nalmefene 20 mg as needed for 24 weeks. The long-term safety and efficacy of nalmefene 20 mg during the total 48-week period were evaluated. Treatment-emergent adverse events during the study period were recorded and change from baseline in the number of heavy drinking days and total alcohol consumption were calculated.

RESULTS

Overall, long-term nalmefene 20 mg was well tolerated; the main treatment-emergent adverse events reported in ≥5% of patients included nasopharyngitis (37.2%), nausea (36.5%), somnolence (21.2%), dizziness (16.8%), malaise (14.6%), and vomiting (12.4%). The number of heavy drinking days and total alcohol consumption decreased from baseline to 48 weeks (mixed model for repeated measures, least squares mean ± standard error, -15.09 ± 0.77 days/month and -53.20 ± 2.29 g/day, respectively) during the study.

CONCLUSION

This long-term evaluation in Japanese patients with high or very high drinking risk levels of alcohol dependence indicated that nalmefene was safe, well tolerated, and efficacious.

GluN2A-selective positive allosteric modulator-nalmefene-flumazenil reverses ketamine-fentanyl-dexmedetomidine-induced anesthesia and analgesia in rats

Anesthetics are used to produce hypnosis and analgesic effects during surgery, but anesthesia for a long time after the operation is not conducive to the recovery of animals or patients. Therefore, finding appropriate treatments to counter the effects of anesthetics could enhance postoperative recovery. In the current study, we discovered the novel role of a GluN2A-selective positive allosteric modulator (PAM) in ketamine-induced anesthesia and investigated the effects of the PAM combined with nalmefene and flumazenil (PNF) in reversing the actions of an anesthetic combination (ketamine-fentanyl-dexmedetomidine, KFD). PAM treatment dose-dependently decreased the duration of the ketamine-induced loss of righting reflex (LORR). Compared with those in the KFD group, the duration of LORR and the analgesic effect of the KFD + PNF group were obviously decreased. Meanwhile, successive administration of PNF and KFD had no adverse effects on the cardiovascular and respiratory systems. Both the KFD group and the KFD + PNF group showed no changes in hepatic and renal function or cognitive function in rats. Moreover, the recovery of motor coordination of the KFD + PNF group was faster than that of the KFD group. In summary, our results suggest the potential application of the PNF combination as an antagonistic treatment strategy for anesthesia.

The Human Laboratory and Drug Development in Alcohol Use Disorder: Recent Updates

Despite a number of approved medications for alcohol use disorder (AUD), this chronic relapsing disease still produces a considerable global burden, with both health-related and financial consequences. While clinical trials are a critical step in drug development, human laboratory studies provide the field with means of screening pharmacotherapy for more nuanced aspects of AUD. Specifically, studies employing alcohol administration techniques (e.g., alcohol challenge and self-administration) are able to investigate potential drugs with respect to their ability to alter various responses to alcohol administration or alter alcohol consumption in laboratory settings. This chapter reviews methodological designs and provides updates from alcohol administration studies used to screen for potential AUD pharmacotherapy over the past decade. These recent studies have supported the efficacy of approved drugs, identified some promising novel drugs, and investigated other drugs that appear ineffective in AUD treatment. Yet, few drugs are explored using the different variants of alcohol administration methods, and using the different methods has provided inconsistent results for the same drug. Future research would aid advancement in the field by testing medication with various methodologies and refining recently developed techniques.

Safety of nalmefene for the treatment of alcohol use disorder: an update

Introduction: Reduced drinking has been debated as a treatment goal for heavy drinking alcohol-dependent patients, in whom treatment based on abstinence is not always an option. Nalmefene was the first drug approved by the European Medicines Agency (2013) with the indication of reduced drinking in high drinking risk level alcohol-dependent patients. Six years after its introduction in Europe, data from clinical experience can be compared with those from preclinical studies and pivotal registration studies to evaluate what nalmefene has added to the treatment of AUD.Areas covered: Systematic review of efficacy and safety data of nalmefene use in humans from preclinical, phase III and phase IV studies, including systematic reviews, meta-analyses, cost-effectiveness analyses, and other secondary analyses.Expert opinion: Nalmefene introduces a paradigm change in the treatment of AUD that makes it appealing to patients that are reluctant to embrace abstinence, and facilitate patient-centered care in heavy users. However, information regarding safety data in special populations (e.g., patients with alcohol-related diseases, pregnancy, psychiatric disease), and direct comparisons with other potential drugs for alcohol reduction are further needed. Despite the promising role of nalmefene, there are still some factors that limit its wide prescription further than in specialized settings.

The effects of nalmefene on emotion processing in alcohol use disorder - A randomized, controlled fMRI study

Nalmefene is a µ- and δ-opioid receptor antagonist and a partial κ-opioid receptor agonist. The drug is suggested to reduce the craving for, and the consumption of alcohol effectively, also alleviating anxiety and anhedonia. The present fMRI study is the first to investigate the processing of emotions as a possible mechanism of action of nalmefene in humans. Fifteen non-treatment-seeking participants suffering from alcohol use disorder (AUD) (24-66 years; 5 females) finished this randomized, placebo controlled, double blind study. Following a cross over design, participants received either a single dose nalmefene or a placebo, with an interval of one week between sessions. Using fMRI, we investigated neural reactivity during the presentation of emotional faces picture sets. Additionally, we performed a visual dot-probe task to detect nalmefene's effects on attentional bias. We detected an increase in the response to emotional faces in the supramarginal gyrus, the angular gyrus as well as the putamen in the nalmefene vs. placebo condition. However, contradictory to our initial hypotheses, amygdala activation was not altered significantly in the placebo condition - a limitation, which might be associated with a lack of activation in the placebo condition maybe due to the small sample size. Attentional bias analyses revealed an interaction effect by trend, which was driven by a significant effect in a sub-analysis showing increased attentional shift towards happy compared to fearful facial expressions under nalmefene. Nalmefene increased brain activation in areas responsible for empathy, social cognition and behavior, which might help alleviating the reinforcing properties of alcohol.

Nalmefene in alcohol-dependent patients with a high drinking risk: Randomized controlled trial

AIMS

Reducing alcohol consumption is one treatment approach for alcohol-dependent patients. This study compared nalmefene 20 mg and 10 mg with placebo, combined with psychosocial support, in alcohol-dependent Japanese patients with a high or very high drinking risk level (DRL).

METHODS

This was a multicenter, randomized, double-blind, phase 3 study conducted in alcohol-dependent patients with a high or very high DRL. Patients were randomized to 24 weeks of treatment with as-needed nalmefene 20 mg, 10 mg, or placebo with psychosocial support. The primary endpoint was change in heavy drinking days (HDD) from baseline to week 12. A key secondary endpoint was the change in total alcohol consumption (TAC) from baseline to week 12.

RESULTS

At week 12, 234, 206, and 154 patients who received placebo, nalmefene 20 mg, and 10 mg were included in the primary endpoint analysis. Compared with placebo, nalmefene was associated with significant reductions in HDD at week 12 (difference in 20 mg group, -4.34 days/month; 95% confidence interval [CI]: -6.05 to -2.62; P < 0.0001; difference in 10 mg group, -4.18 days/month; 95%CI: -6.05 to -2.32; P < 0.0001), as well as a significant reduction in TAC at week 12 (P < 0.0001). The incidence of treatment-emergent adverse events was 87.9%, 84.8%, and 79.2% in the groups receiving nalmefene 20 mg, 10 mg, and placebo, respectively. These events were mostly of mild or moderate severity.

CONCLUSIONS

Nalmefene 20 mg or 10 mg effectively reduced alcohol consumption and was well tolerated in alcohol-dependent patients with a high or very high DRL.

Mild Effect of Nalmefene on Alcoholic Cue-Induced Response Invigoration in Alcohol Use Disorder Without Accompanying Changes in Electrophysiological Signatures of Early Visual Processing and Executive Control

Nalmefene is approved for as-needed pharmacological treatment in alcohol use disorder (AUD) by the European Medicines Agency. While the cellular effects of nalmefene have been thoroughly investigated, data are very limited on how this agent influences neural signals associated with inhibitory control and the visual analysis of environmental cues. This double-blind crossover study assessed the behavioral and neural effects of acute nalmefene administration in patients diagnosed with AUD. In experiment 1, we validated our experimental paradigm (electroencephalography combined with a modified Go/NoGo task using images of alcoholic and nonalcoholic drinks as prime stimuli) in 20 healthy adults to ensure that our protocol is suitable for assessing the behavioral and neural aspects of executive control. In experiment 2, we recruited 19 patients with AUD, and in a double-blind crossover design, we investigated the effects of nalmefene versus placebo on task performance (response accuracy, the sensitivity index, and reaction times), visual responses to appetitive cues (occipital P1, N1, and P2 components), and electrophysiological markers of conflict detection and response inhibition (frontal N2 and P3 waveforms). Under placebo, patients produced faster reaction times to alcohol-primed Go stimuli, an effect that was weak despite being statistically significant. However, the effect of alcoholic cues on the speed of response initiation disappeared after receiving nalmefene. We found no placebo versus nalmefene difference regarding our patients’ ability to accurately inhibit responses to NoGo stimuli or for occipital and frontal event-related potentials. Our results suggest that nalmefene might be potent in reducing the vigor to act upon alcoholic cues in AUD patients, but this effect is most probably mediated via subcortical (rather than cortical) neural circuits.

Advances in the science and treatment of alcohol use disorder

Alcohol is a major contributor to global disease and a leading cause of preventable death, causing approximately 88,000 deaths annually in the United States alone. Alcohol use disorder is one of the most common psychiatric disorders, with nearly one-third of U.S. adults experiencing alcohol use disorder at some point during their lives. Alcohol use disorder also has economic consequences, costing the United States at least $249 billion annually. Current pharmaceutical and behavioral treatments may assist patients in reducing alcohol use or facilitating alcohol abstinence. Although recent research has expanded understanding of alcohol use disorder, more research is needed to identify the neurobiological, genetic and epigenetic, psychological, social, and environmental factors most critical in the etiology and treatment of this disease. Implementation of this knowledge in clinical practice and training of health care providers is also needed to ensure appropriate diagnosis and treatment of individuals suffering from alcohol use disorder.

Clinically utilized kappa-opioid receptor agonist nalfurafine combined with low-dose naltrexone prevents alcohol relapse-like drinking in male and female mice

Alcohol relapse is a treatment goal for alcohol dependence and the target for medications' development. Clinically utilized nalfurafine (NFF) is a potent and selective kappa- opioid receptor (KOP-r) agonist, with fewer side effects (e.g., sedation or anhedonia) than classic KOP-r full agonists. We have recently found that NFF reduces excessive alcohol drinking in mice via a KOP-r-mediated mechanism. Here, we further investigated whether NFF alone (1-10 μg/kg) or in combination with naltrexone (NTX, mu-opioid receptor [MOP-r] antagonist) altered alcohol relapse-like drinking using a mouse alcohol deprivation effect (ADE) paradigm to mimic the relapse episodes in human alcoholics. Nalmefene (NMF, clinically utilized KOP-r partial agonist with MOP-r antagonism) was used as a reference compound for the effects on mouse ADE of new NFF + NTX combination. After exposed to 3-week intermittent- access alcohol drinking (two-bottle choice, 24-h access every other day), both male and female mice displayed excessive alcohol intake and then pronounced ADE after 1-week abstinence. NFF prevented the ADE in a dose-dependent manner in both male and female mice. A combination of NFF with NTX reduced the ADE without sex differences at doses lower than those individual effective ones, suggesting synergistic effects between the two compounds. NMF prevented the ADE in both sexes, while selective KOP-r antagonist nor-BNI had no effect. Our new study suggests that a combination of clinically-utilized, potent KOP-r agonist NFF with low-dose NTX has therapeutic potential in alcohol "relapse" treatment.

Therapeutic Prospects of Cannabidiol for Alcohol Use Disorder and Alcohol-Related Damages on the Liver and the Brain

Background: Cannabidiol (CBD) is a natural component of cannabis that possesses a widespread and complex immunomodulatory, antioxidant, anxiolytic, and antiepileptic properties. Much experimental data suggest that CBD could be used for various purposes in alcohol use disorder (AUD) and alcohol-related damage on the brain and the liver. Aim: To provide a rationale for using CBD to treat human subjects with AUD, based on the findings of experimental studies. Methods: Narrative review of studies pertaining to the assessment of CBD efficiency on drinking reduction, or on the improvement of any aspect of alcohol-related toxicity in AUD. Results: Experimental studies find that CBD reduces the overall level of alcohol drinking in animal models of AUD by reducing ethanol intake, motivation for ethanol, relapse, anxiety, and impulsivity. Moreover, CBD reduces alcohol-related steatosis and fibrosis in the liver by reducing lipid accumulation, stimulating autophagy, modulating inflammation, reducing oxidative stress, and by inducing death of activated hepatic stellate cells. Finally, CBD reduces alcohol-related brain damage, preventing neuronal loss by its antioxidant and immunomodulatory properties. Conclusions: CBD could directly reduce alcohol drinking in subjects with AUD. Any other applications warrant human trials in this population. By reducing alcohol-related steatosis processes in the liver, and alcohol-related brain damage, CBD could improve both hepatic and neurocognitive outcomes in subjects with AUD, regardless of the individual's drinking trajectory. This might pave the way for testing new harm reduction approaches in AUD, in order to protect the organs of subjects with an ongoing AUD.

Drinking Levels and Profiles of Alcohol Addicted Rats Predict Response to Nalmefene

Background: Pharmacotherapeutic options supporting the treatment of alcohol dependence are recommended and available but underutilized, partly due to questions about efficacy. Nalmefene, a μ-opioid receptor antagonist and partial kappa receptor agonist, is recommended for reduction of alcohol consumption, but evidence about its effectiveness has been equivocal; identifying factors which predict response will help optimize treatment.

Methods: The alcohol deprivation effect paradigm is a tightly controlled procedure comprising repeated deprivation and reintroduction phases, leading to increased preference for alcohol; reintroduction approximates relapse. Using a digital drinkometer system measuring high-resolution drinking behavior, we examined the effects of nalmefene on relapse drinking behavior in alcohol addicted rats. We also tested whether drinking behavior in the relapse phase prior to nalmefene administration predicted treatment response. We further examined whether longitudinal drinking behavior and locomotor activity predicted treatment response.

Results: Our results showed that nalmefene (0.3 mg/kg) reduced relapse-like consumption significantly (∼20%) compared to vehicle on the first 2 days of alcohol reintroduction. Examining the first 6 h of a preceded treatment-free relapse episode revealed drinking patterns clustering the rats into responders (reduction of >40%, n = 17) and non-responders (reduction of <40%, n = 7) to subsequent nalmefene treatment. During the first 6 h of the preceding relapse phase, responders consumed more alcohol than non-responders; the amount of alcohol consumed during each drinking approach was larger but frequency of drinking did not differ. Longitudinal drinking behavior and locomotor activity did not significantly predict response.

Conclusion: Our results suggest that nalmefene reduces alcohol intake during a relapse-like situation but effectiveness can differ greatly at the individual level. However, who responds may be informed by examining drinking profiles and rats that show high drinking levels prior to treatment are more likely to respond to nalmefene.

Psychotic Decompensation During Nalmefene Treatment in a Patient With Schizoaffective Disorder: A Case Report

Objective: Nalmefene is a kappa-opioid receptor agonist/antagonist which is currently prescribed to reduce heavy drinking days. Adverse events (AEs) have previously been described in trials, but these trials excluded patients with psychiatric comorbidities. This is important as psychiatric disorders are frequently associated with alcohol use disorders; therefore, the specific AEs in this population should be investigated. Methods: Here, we describe the case of a patient with diagnosed alcohol use disorder and schizoaffective disorder who received treatment with nalmefene. Results: The patient showed decompensation of psychotic symptoms after two doses of medication, consisting of auditory hallucinations, delusions, and ideas of persecution. The symptoms improved two days after treatment discontinuation. Conclusions: This case indicates that the AEs of nalmefene should be specifically investigated in patients with psychiatric disorders.

Bifunctional opioid receptor ligands as novel analgesics

Prolonged treatment of chronic severe pain with opioid analgesics is frought with problematic adverse effects including tolerance, dependence, and life-threatening respiratory depression. Though these effects are mediated predominately through preferential activation of μ opioid peptide (μOP) receptors, there is an emerging appreciation that actions at κOP and δOP receptors contribute to the observed pharmacologic and behavioral profile of μOP receptor agonists and may be targeted simultaneously to afford improved analgesic effects. Recent developments have also identified the related nociceptin opioid peptide (NOP) receptor as a key modulator of the effects of μOP receptor signaling. We review here the available literature describing OP neurotransmitter systems and highlight recent drug and probe design strategies.

State-of-the-art behavioral and pharmacological treatments for alcohol use disorder

BACKGROUND

Alcohol use disorder (AUD) and its associated consequences remain significant public health concerns. Given that AUD represents a spectrum of severity, treatment options represent a continuum of care, ranging from single-session brief interventions to more intensive, prolonged, and specialized treatment modalities.

OBJECTIVE

This qualitative literature review seeks to describe the best practices for AUD by placing a particular emphasis on identifying those practices which have received the most empirical support.

METHOD

This review summarizes psychological and pharmacological intervention options for AUD treatment, with a focus on the relapse prevention phase of recovery. Psychological and pharmacological treatments are summarized in terms of the empirical evidence favoring each approach and the level of AUD severity for which they are most indicated.

SCIENTIFIC SIGNIFICANCE

One of the broad assertions from this review is that while AUD is highly prevalent, seeking treatment for AUD is not. There are a myriad of behavioral and pharmacological treatments that have shown compelling evidence of efficacy for the treatment of AUD. In the behavioral treatment literature, cognitive behavioral therapy has received the most consistent support. Opioid antagonism (via naltrexone) has been the most widely studied pharmacotherapy and has produced moderate effect sizes. While none of the treatments reviewed herein represents a so-called silver bullet for AUD, they each have the potential to significantly improve the odds of recovery. Precision medicine, or the identification of best treatment matches for individual patients, looms as an important overarching goal for the field, although specific matches are not yet sufficiently reliable in their empirical evidence to warrant clinical dissemination.

PPARα/CB1 receptor dual ligands as a novel therapy for alcohol use disorder: Evaluation of a novel oleic acid conjugate in preclinical rat models

Recent studies have demonstrated the utility of drugs modulating the endogenous cannabinoid system to control excessive alcohol intake. Among them, drugs interacting with acylethanolamide receptors including cannabinoid CB1 receptor antagonists/inverse agonists, peroxisome proliferator-activated receptor alpha (PPARα) agonists or peroxisome proliferator-activated receptor gamma (PPARγ) agonists have demonstrated utility in the reduction of alcohol intake in animal models. However, few studies have addressed the potential utility of combining these classes of drugs, especially because of expected safety problems. In the present work we took the advantage of the availability of two novel dual ligands for these receptors, to test the hypothesis that these types of drugs might reproduce and even improve the pharmacological profile of those drugs interacting with single targets. To this end we tested (R)-3-[(4-Benzyl-2-oxooxazolidin-3-yl)methyl]-N-[4-(dodecylcarbamoyl)phenyl]benzamide (NF 10-360), a dual PPARα/γ agonist, and N-[1-(3,4-dihydroxyphenyl)propan-2-yl]oleamide (OLHHA), a dual CB1 receptor antagonist/PPARα agonist, in animal models of alcohol consumption. Both drugs were effective in reducing alcohol intake and alcohol self-administration, being OLHHA a very potent alcohol intake inhibitor (EC₅₀ 0.2 mg/kg). OLHHA also reduced self-administration of the opioid oxycodone. OLHHA actions on alcohol self-administration were replicated in alcohol-preferring Marchigian-Sardinian msP rats. Repeated administration of OLHHA did result neither in tolerance nor in toxicological or deleterious metabolic changes in the liver of msP rats. These data support the feasibility of developing novel dual ligands interacting with cannabinoid targets to treat alcohol use disorder in humans.

Constraining Endomorphin-1 by β,α-Hybrid Dipeptide/Heterocycle Scaffolds: Identification of a Novel κ-Opioid Receptor Selective Partial Agonist

Herein we present the expedient synthesis of endomorphin-1 analogues containing stereoisomeric β²-homo-Freidinger lactam-like scaffolds ([Amo²]EM), and we discuss opioid receptor (OR) affinity, enzymatic stability, functional activity, in vivo antinociceptive effects, and conformational and molecular docking analysis. Hence, H-Tyr-Amo-Trp-PheNH₂ resulted to be a new chemotype of highly stable, selective, partial KOR agonist inducing analgesia, therefore displaying great potential interest as a painkiller possibly with reduced harmful side effects.

Efficacy and safety of sodium oxybate in alcohol-dependent patients with a very high drinking risk level

Medication development for alcohol relapse prevention or reduction of consumption is highly challenging due to methodological issues of pharmacotherapy trials. Existing approved medications are only modestly effective with many patients failing to benefit from these therapies. Therefore, there is a pressing need for other effective treatments with a different mechanism of action, especially for patients with very high (VH) drinking risk levels (DRL) because this is the most severely affected population of alcohol use disorder patients. Life expectancy of alcohol-dependent patients with a VH DRL is reduced by 22 years compared with the general population and approximately 90 000 alcohol-dependent subjects with a VH DRL die prematurely each year in the EU (Rehm et al. ). A promising new medication for this population is sodium oxybate, a compound that acts on GABA_B receptors and extrasynaptic GABA_A receptors resulting in alcohol-mimetic effects. In this article, a European expert group of alcohol researchers and clinicians summarizes data (a) from published trials, (b) from two new-as yet unpublished-large clinical trials (GATE 2 (n = 314) and SMO032 (n = 496), (c) from post hoc subgroup analyses of patients with different WHO-defined DRLs and (d) from multiple meta-analyses. These data provide convergent evidence that sodium oxybate is effective especially in a subgroup of alcohol-dependent patients with VH DRLs. Depending on the study, abstinence rates are increased up to 34 percent compared with placebo with risk ratios up to 6.8 in favor of sodium oxybate treatment. These convergent data are supported by the clinical use of sodium oxybate in Austria and Italy for more than 25 years. Sodium oxybate is the sodium salt of γ-hydroxybutyric acid that is also used as a recreational (street) drug suggestive of abuse potential. However, a pharmacovigilance database of more than 260 000 alcohol-dependent patients treated with sodium oxybate reported very few adverse side effects and only few cases of abuse. We therefore conclude that sodium oxybate is an effective, well-tolerated and safe treatment for withdrawal and relapse prevention treatment, especially in alcohol-dependent patients with VH DRL.

Defending psychiatry or defending the trivial effects of therapeutic interventions? A citation content analysis of an influential paper

AIMS

Leucht et al. in 2012 described an overview of meta-analyses of the efficacy of medication in psychiatry and general medicine, concluding that psychiatric drugs were not less efficacious than other drugs. Our goal was to explore the dissemination of this highly cited paper, which combined a thought provoking message with a series of caveats.

METHODS

We conducted a prospectively registered citation content analysis. All papers published before June 1st citing the target paper were independently rated by two investigators. The primary outcome coded dichotomously was whether the citation was used to justify a small or modest effect observed for a given treatment. Secondary outcomes regarded mentioning any caveats when citing the target paper, the point the citation was making (treatment effectiveness in psychiatry closely resembles that in general medicine, others), the type of condition (psychiatric, medical or both), specific disease, treatment category and specific type. We also extracted information about the type of citing paper, financial conflict of interest (COI) declared and any industry support. The primary analysis was descriptive by tabulating the extracted variables, with numbers and percentages where appropriate. Co-authorship networks were constructed to identify possible clusters of citing authors. An exploratory univariate logistic regression was used to explore the relationship between each of a subset of pre-specified secondary outcomes and the primary outcome.

RESULTS

We identified 135 records and retrieved and analysed 120. Sixty-three (53%) quoted Leucht et al.'s paper to justify a small or modest effect observed for a given therapy, and 113 (94%) did not mention any caveats. Seventy-two (60%) used the citation to claim that treatment effectiveness in psychiatry closely resembles that in general medicine; 110 (91%) paper were about psychiatric conditions. Forty-one (34%) papers quoted it without pointing towards any specific treatment category, 28 (23%) were about antidepressants, 18 (15%) about antipsychotics. Forty (33%) of the citing papers included data. COIs were reported in 55 papers (46%). Univariate and multivariate regressions showed an association between a quote justifying small or modest effects and the point that treatment effectiveness in psychiatry closely resembles that in general medicine.

CONCLUSIONS

Our evaluation revealed an overwhelmingly uncritical reception and seemed to indicate that beyond defending psychiatry as a discipline, the paper by Leucht et al. served to lend support and credibility to a therapeutic myth: trivial effects of mental health interventions, most often drugs, are to be expected and therefore accepted.Protocol registration: https://osf.io/9dqat/.

Polysubstance and Behavioral Addictions in a Patient with Bipolar Disorder: Role of Lifetime Subthreshold Autism Spectrum

This case report draws attention to the potential relevance of undetected autism spectrum symptoms in a bipolar patient with high work functioning showing a peculiar addictive profile with impulsive and antisocial behaviors. A 23-year-old man with a diagnosis of Bipolar Disorder (BD) and Substance Use Disorder (SUD) was hospitalized at the Psychiatric Clinic of the University of Pisa for diuretics and β-2 adrenergic agonist abuse in a remission phase of benzodiazepines and substance abuse. He reported a history of behavioral addictions in the framework of a global high work functioning with particular skills in computer science. When assessed for adult autism spectrum symptoms, despite not fulfilling a DSM-5 diagnosis of Autism Spectrum Disorder (ASD), he reported a score of 93/240 at the Ritvo Autism and Asperger Diagnostic Scale (RAADS-r) and of 88/160 at the Adult Autism Subthreshold Spectrum (AdAS Spectrum), both indicative of ASD. We argue the possible role of adult subthreshold autism spectrum features, generally disregarded in adult psychiatry, in the peculiar addictive profile developed by this patient with BD that may deserve appropriate treatment.