Baclofen administration for the treatment of affective disorders in alcoholic patients

Chronic ethanol exposure in mice evokes pre- and postsynaptic deficits in GABAergic transmission in ventral tegmental area GABA neurons

BACKGROUND AND PURPOSE

GABAergic neurons in mouse ventral tegmental area (VTA) exhibit elevated activity during withdrawal following chronic ethanol exposure. While increased glutamatergic input and decreased GABAA receptor sensitivity have been implicated, the impact of inhibitory signaling in VTA GABA neurons has not been fully addressed.

EXPERIMENTAL APPROACH

We used electrophysiological and ultrastructural approaches to assess the impact of chronic intermittent ethanol vapour exposure in mice on GABAergic transmission in VTA GABA neurons during withdrawal. We used CRISPR/Cas9 ablation to mimic a somatodendritic adaptation involving the GABAB receptor (GABABR) in ethanol-naïve mice to investigate its impact on anxiety-related behaviour.

KEY RESULTS

The frequency of spontaneous inhibitory postsynaptic currents was reduced in VTA GABA neurons following chronic ethanol treatment and this was reversed by GABABR inhibition, suggesting chronic ethanol strengthens the GABABR-dependent suppression of GABAergic input to VTA GABA neurons. Similarly, paired-pulse depression of GABAA receptor-dependent responses evoked by optogenetic stimulation of nucleus accumbens inputs from ethanol-treated mice was reversed by GABABR inhibition. Somatodendritic currents evoked in VTA GABA neurons by GABABR activation were reduced following ethanol exposure, attributable to the suppression of GIRK (Kir3) channel activity. Mimicking this adaptation enhanced anxiety-related behaviour in ethanol-naïve mice.

CONCLUSIONS AND IMPLICATIONS

Chronic ethanol weakens the GABAergic regulation of VTA GABA neurons in mice via pre- and postsynaptic mechanisms, likely contributing to their elevated activity during withdrawal and expression of anxiety-related behaviour. As anxiety can promote relapse during abstinence, interventions targeting VTA GABA neuron excitability could represent new therapeutic strategies for treatment of alcohol use disorder.

Astrocytic GABAergic Regulation in Alcohol Use and Major Depressive Disorders

Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system (CNS). Most GABAergic neurons synthesize GABA from glutamate and release it in the synaptic cleft in the CNS. However, astrocytes can also synthesize and release GABA, activating GABA receptors in the neighboring neurons in physiological and pathological conditions. As the primary homeostatic glial cells in the brain, astrocytes play a crucial role in regulating GABA homeostasis and synaptic neurotransmission. Accumulating evidence demonstrates that astrocytic GABA dysregulation is implicated in psychiatric disorders, including alcohol use disorder (AUD) and major depressive disorder (MDD), the most prevalent co-occurring psychiatric disorders. Several current medications and emerging pharmacological agents targeting GABA levels are in clinical trials for treating AUD and MDD. This review offers a concise summary of the role of astrocytic GABA regulation in AUD and MDD. We also provide an overview of the current understanding and areas of debate regarding the mechanisms by which astrocytes regulate GABA in the CNS and their potential significance in the molecular basis of AUD and MDD, paving the way toward future research directions and potential therapeutic target areas within this field.

Baclofen for alcohol use disorder

BACKGROUND

Alcohol use disorder (AUD) is one of the most widespread psychiatric disorders leading to detrimental consequences to people with this disorder and others. Worldwide, the prevalence of heavy episodic drinking (30-day prevalence of at least one occasion of 60 g of pure alcohol intake among current drinkers) is estimated at 20% and the prevalence of AUD at 5% of the adult general population, with highest prevalence in Europe and North America. Therapeutic approaches, including pharmacotherapy, play an important role in treating people with AUD. This is an update of a Cochrane Review first published in 2018.

OBJECTIVES

To evaluate the benefits and harms of baclofen on achieving and maintaining abstinence or reducing alcohol consumption in people with AUD compared to placebo, no treatment or any other pharmacological relapse prevention treatment.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was 22 November 2021.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of at least four weeks' treatment duration and 12 weeks' overall study duration comparing baclofen for AUD treatment with placebo, no treatment or other treatments.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. relapse, 2. frequency of use, 3. amount of use, 4. adverse events, 5. dropouts from treatment and 6. dropouts from treatment due to adverse events. Our secondary outcomes were 7. craving, 8. anxiety, 9. depression and 10. frequency of most relevant adverse events.

MAIN RESULTS

We included 17 RCTs (1818 participants) with a diagnosis of alcohol dependence according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition or International Classification of Diseases 10th edition criteria. Mean age was 46.5 years and 70% were men. Ten studies compared baclofen to placebo or another medication; seven compared two baclofen doses to placebo or another medication. Globally, 15 studies compared baclofen to placebo, two baclofen to acamprosate and two baclofen to naltrexone. In 16 studies, participants received psychosocial treatments. We judged most studies at low risk of selection, performance, detection (subjective outcome), attrition and reporting bias. Ten studies detoxified participants before treatment; in seven studies, participants were still drinking at the beginning of treatment. Treatment duration was 12 weeks for 15 RCTs and longer in two studies. Baclofen daily dose was 30 mg to 300 mg: 10 RCTs used low doses (30 mg or less); eight RCTs medium doses (above 30 and 100 mg or less) and four RCTs high doses (above 100 mg). Compared to placebo, moderate-certainty evidence found that baclofen probably decreases the risk to relapse (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.77 to 0.99; 12 studies, 1057 participants). This result was confirmed among detoxified participants but not among other subgroups of participants. High-certainty evidence found that baclofen increases the percentage of days abstinent (mean difference (MD) 9.07, 95% CI 3.30 to 14.85; 16 studies, 1273 participants). This result was confirmed among all subgroups of participants except non-detoxified or those who received medium doses. There was no difference between baclofen and placebo in the other primary outcomes: heavy drinking days (standardised mean difference (SMD) -0.18, 95% CI -0.48 to 0.11; 13 studies, 840 participants; moderate-certainty evidence); number of drinks per drinking days (MD -0.45, 95% CI -1.20 to 0.30; 9 studies, 392 participants; moderate-certainty evidence); number of participants with at least one adverse event (RR 1.05, 95% CI 0.99 to 1.11; 10 studies, 738 participants; high-certainty evidence); dropouts (RR 0.88, 95% CI 0.74 to 1.03; 17 studies, 1563 participants; high-certainty evidence); dropouts due to adverse events (RR 1.39, 95% CI 0.89 to 2.18; 16 studies, 1499 participants; high-certainty evidence). These results were confirmed by subgroup analyses except than for the dropouts that resulted lower among participants who received high doses of baclofen and studies longer than 12 weeks. Compared to placebo, there was no difference in craving (SMD -0.16, 95% CI -0.37 to 0.04; 17 studies, 1275 participants), anxiety (MD -0.01, 95% CI -0.14 to 0.11; 15 studies, 1123 participants) and depression (SMD 0.07, 95% CI -0.12 to 0.27; 11 studies, 1029 participants). Concerning the specific adverse events, baclofen increases fatigue, dizziness, somnolence/sedation, dry mouth, paraesthesia and muscle spasms/rigidity. There was no difference in the other adverse events. Compared to acamprosate, one study (60 participants) found no differences in any outcomes but the evidence was very uncertain: relapse (RR 1.25, 95% CI 0.71 to 2.20; very low-certainty evidence); number of participants with at least one adverse event (RR 0.63, 95% CI 0.23 to 1.69; very low-certainty evidence); dropouts (RR 0.56, 95% CI 0.21 to 1.46; very low-certainty evidence); dropouts due to adverse events (RR 0.33, 95% CI 0.01 to 7.87; very low-certainty evidence) and craving (MD 5.80, 95% CI -11.84 to 23.44); and all the adverse events evaluated. Compared to naltrexone, baclofen may increase the risk of relapse (RR 2.50, 95% CI 1.12 to 5.56; 1 study, 60 participants; very low-certainty evidence) and decrease the number of participants with at least one adverse event (RR 0.35, 95% CI 0.15 to 0.80; 2 studies, 80 participants; very low-certainty evidence) but the evidence is very uncertain. One study (60 participants) found no difference between baclofen and naltrexone in the dropouts at the end of treatment (RR 1.00, 95% CI 0.32 to 3.10; very low-certainty evidence), craving (MD 2.08, 95% CI -3.71 to 7.87), and all the adverse events evaluated.

AUTHORS' CONCLUSIONS

Baclofen likely reduces the risk of relapse to any drinking and increases the percentage of abstinent days, mainly among detoxified participants. It does not increase the number of participants with at least one adverse event, those who dropout for any reason or due to adverse events. It probably does not reduce number of heavy drinking days and the number of drinks per drinking days. Current evidence suggests that baclofen may help people with AUD in maintaining abstinence. The results of comparisons of baclofen with acamprosate and naltrexone were mainly based on only one study.

FORWARDS-1: an adaptive, single-blind, placebo-controlled ascending dose study of acute baclofen on safety parameters in opioid dependence during methadone-maintenance treatment-a pharmacokinetic-pharmacodynamic study

Background

Treatment of opiate addiction with opiate substitution treatment (e.g. methadone) is beneficial. However, some individuals desire or would benefit from abstinence but there are limited options to attenuate problems with opiate withdrawal. Preclinical and preliminary clinical evidence suggests that the GABA-B agonist, baclofen, has the desired properties to facilitate opiate detoxification and prevent relapse. This study aims to understand whether there are any safety issues in administering baclofen to opioid-dependent individuals receiving methadone.

Methods

Opiate-dependent individuals (DSM-5 severe opioid use disorder) maintained on methadone will be recruited from addiction services in northwest London (NHS and third sector providers). Participants will be medically healthy with no severe chronic obstructive pulmonary disease or type 2 respiratory failure, no current dependence on other substances (excluding nicotine), no current severe DSM-5 psychiatric disorders, and no contraindications for baclofen or 4800 IU vitamin D (placebo). Eligible participants will be randomised in a 3:1 ratio to receive baclofen or placebo in an adaptive, single-blind, ascending dose design. A Bayesian dose-escalation model will inform the baclofen dose (10, 30, 60, or 90 mg) based on the incidence of ‘dose-limiting toxicity’ (DLT) events and participant-specific methadone dose. A range of respiratory, cardiovascular, and sedative measures including the National Early Warning Score (NEWS2) and Glasgow Coma Scale will determine DLT. On the experimental day, participants will consume their usual daily dose of methadone followed by an acute dose of baclofen or placebo (vitamin D3) ~ 1 h later. Measures including oxygen saturation, transcutaneous CO₂, respiratory rate, QTc interval, subjective effects (sedation, drug liking, craving), plasma levels (baclofen, methadone), and adverse events will be obtained using validated questionnaires and examinations periodically for 5 h after dosing.

Discussion

Study outcomes will determine what dose of baclofen is safe to prescribe to those receiving methadone, to inform a subsequent proof-of-concept trial of the efficacy baclofen to facilitate opiate detoxification. To proceed, the minimum acceptable dose is 30 mg of baclofen in patients receiving ≤ 60 mg/day methadone based on the clinical experience of baclofen’s use in alcoholism and guidelines for the management of opiate dependence.

Trial registration

Clinicaltrials.gov NCT05161351. Registered on 16 December 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06821-9.

The influence of anxiety symptoms on clinical outcomes during baclofen treatment of alcohol use disorder: A systematic review and meta-analysis

Given the high coexistence of anxiety symptoms in people with alcohol use disorder (AUD), we aimed to determine the influence of anxiety symptoms on outcomes in patients with AUD treated with the GABA_B receptor agonist baclofen. A meta-analysis of 13 comparisons (published 2010-2020) including baseline and outcome data on alcohol consumption and anxiety after 12 weeks was undertaken. There were significantly higher rates of abstinent days in patients treated with baclofen compared to placebo (p = 0.004; high certainty evidence); specifically in those with higher baseline anxiety levels (p < 0.00001; high certainty evidence) compared to those with lower baseline anxiety levels (p = 0.20; moderate certainty evidence). The change in anxiety ratings over 12 weeks did not differ between those treated with baclofen or placebo (p = 0.84; moderate certainty evidence). This may be due to different anxiety constructs being measured by scales not validated in this patient group, or that anxiety is not a biobehavioral mechanism by which baclofen may reduce alcohol drinking. Given the prevalence of anxiety symptoms in AUD all these factors warrant further research.

Efficacy of pharmacotherapeutics for patients comorbid with alcohol use disorders and depressive symptoms-A bayesian network meta-analysis

Background

We aimed to compare and rank the efficacy of different pharmacotherapeutics for patients comorbid with alcohol use disorders and depressive symptoms.

Method

Bayesian network meta‐analysis was performed for three different outcome parameters: alcohol use disorders (AUD) remission rate, percent abstinent days, and scores of depression scales. The surface under the cumulative ranking curves (SUCRA) was used for ranking the efficacy of interventions. Sensitivity analysis and direct pairwise analysis were conducted to validate the main results.

Results

A total of 68 RCTs consisting of 5890 patients were included. Disulfiram could significantly increase the AUD remission rates (OR 5.02, 1.97‐12.95) and the percent abstinent days (MD 17.08, 3.48‐30.93). Disulfiram was associated with the best efficacy in achieving remission (SUCRA 95.1%) and increasing abstinent days (SUCRA 87.6%). Noradrenaline reuptake inhibitor was significantly more efficacious than controls (SMD −2.44, −3.53 to −1.36) and have the first rank (SUCRA 99.0%) in reducing the scores of depression scales. Antiepileptics have relatively higher ranks in efficacy for both AUD and depressive symptoms.

Conclusions

Disulfiram was associated with the best efficacy in achieving abstinence for comorbidity patients. Noradrenaline reuptake inhibitor was demonstrated to be associated with the best efficacy in reducing scores of depression scales. Antiepileptics might be beneficial to both alcohol‐related and depressive symptoms.

Baclofen for alcohol withdrawal

BACKGROUND

Alcohol withdrawal syndrome (AWS) is a distressing and life-threatening condition that usually affects people who are alcohol dependent when they discontinue or decrease their alcohol consumption. Baclofen shows potential for rapidly reducing symptoms of severe AWS in people with alcoholism. Treatment with baclofen is easy to manage and rarely produces euphoria or other pleasant effects, or craving for the drug. This is an updated version of the original Cochrane Review first published in 2011 and last updated in 2017.

OBJECTIVES

To assess the efficacy and safety of baclofen for people with AWS.

SEARCH METHODS

We updated our searches of the following databases to June 2019: the Cochrane Drugs and Alcohol Group Specialised Register, CENTRAL, PubMed, Embase, and CINAHL. We also searched registers of ongoing trials. We handsearched the references quoted in the identified trials, and sought information from researchers, pharmaceutical companies, and relevant trial authors about unpublished or uncompleted trials. We placed no restrictions on language.

SELECTION CRITERIA

We included all randomised controlled clinical trials (RCTs) evaluating baclofen versus placebo or any other treatment for people with AWS. We excluded uncontrolled, non-randomised, or quasi-randomised trials. We included both parallel group and cross-over studies.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included four RCTs with 189 randomised participants (one RCT new for this update). None of the included studies reported the primary outcomes of alcohol withdrawal seizures, alcohol withdrawal delirium, or craving. For the comparison of baclofen and placebo (1 study, 31 participants), there was no evidence of a difference in Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised (CIWA-Ar) scores in eight-hour periods from days one to five (very low-quality evidence). For the comparison of baclofen and diazepam (2 studies, 85 participants), there was no evidence of a difference in change from baseline to days 10 to 15 on CIWA-Ar scores (very low-quality evidence, meta-analysis was not performed due to insufficient data). In one study (37 participants), there was no evidence of a difference in participants with at least one adverse event (risk difference (RD) 0.00, 95% confidence interval (CI) -0.10 to 0.10; very low-quality evidence), dropouts (RD 0.00, 95% CI -0.10 to 0.10; very low-quality evidence), and dropouts due to adverse events (RD 0.00, 95% CI -0.10 to 0.10; very low-quality evidence). For the comparison of baclofen and chlordiazepoxide (1 study, 60 participants), there was no evidence of a difference in difference from baseline to nine-day decremental fixed-dose intervention: CIWA-Ar scores (mean difference (MD) 1.00, 95% CI 0.70 to 1.30; very low-quality evidence), global improvement (MD 0.10, 95% CI -0.03 to 0.23; very low-quality evidence), 14/60 participants with adverse events (RD 2.50, 95% CI 0.88 to 7.10; very low-quality of evidence), dropouts (RD 0.00, 95% CI -0.06 to 0.06; very low-quality evidence), and dropouts due to adverse events (RD 0.00, 95% CI -0.06 to 0.06; very low-quality evidence). None of the RCTs provided information on random sequence generation or allocation concealment, therefore, we assessed them at unclear risk of bias. Two RCTs were not of double-blind design and had a high risk of bias in blinding (Addolorato 2006; Girish 2016). One RCT had more than 5% dropouts with high risk of attrition bias (Lyon 2011). We could not assess reporting bias as none of the prepublished protocols were available.

AUTHORS' CONCLUSIONS

No conclusions can be drawn about the efficacy and safety of baclofen for the management of alcohol withdrawal because we found insufficient and very low-quality evidence.

Baclofen for alcohol use disorder

BACKGROUND

Alcohol use disorder (AUD) and alcohol-related impairments belong to the most widespread psychiatric disorders leading to specific psychophysical, affective and cognitive symptoms and consequences for psychosocial well-being and health. Alcohol consumption is increasingly becoming a problem in many developing regions and AUD prevalence is estimated at 4.1% worldwide, with highest prevalence in European countries (7.5%), and the North America (6.0%). Therapeutic approaches, including pharmacotherapy, play an important role in treating patients with AUD.

OBJECTIVES

To assess the efficacy and safety of baclofen for treating people with AUD, who are currently drinking, with the aim of achieving and maintaining abstinence or reducing alcohol consumption.

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Specialised Register, CENTRAL, MEDLINE, Embase, two further databases and two clinical trials registries, conference proceedings, and the reference lists of retrieved articles. The date of the most recent search was 30 January 2018.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of at least four weeks' treatment duration and 12 weeks' overall study duration comparing baclofen for relapse prevention of AUD with placebo, no treatment or other treatments.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 12 RCTs (1128 participants). All studies but three recruited fewer than 100 participants. Participants had a diagnosis of alcohol dependence according the Diagnostic and Statistical Manual of Mental Disorders (DSM) IV or the International Classification of Diseases (ICD)-10 criteria who were currently drinking. The mean age of participants was 48 years, and there were more men (69%), than women. All studies compared baclofen to placebo, except for one study that evaluated baclofen versus acamprosate. The included studies considered baclofen at different doses (range 10 mg a day to 150 mg a day). In all but one of the studies, participants in both the baclofen and placebo groups received psychosocial treatment or counselling of various intensity.We judged most of the studies at low risk of selection, performance, detection (subjective outcome), attrition and reporting bias.We did not find any difference between baclofen and placebo for the primary outcomes: relapse-return to any drinking (RR 0.88, 95% CI 0.74 to 1.04; 5 studies, 781 participants, moderate certainty evidence); frequency of use by percentage of days abstinent (MD 0.39, 95% CI -11.51 to 12.29; 6 studies, 465 participants, low certainty evidence) and frequency of use by percentage of heavy drinking days at the end of treatment (MD 0.25, 95% CI -1.25 to 1.76; 3 studies, 186 participants, moderate certainty evidence); number of participants with at least one adverse event (RR 1.04, 95% CI 0.99 to 1.10; 4 studies, 430 participants, high certainty evidence); the dropout rate at the end of treatment (RR 0.98, 95% CI 0.77 to 1.26, 8 studies, 977 participants, high certainty evidence) and dropout due to adverse events (RR 1.11, 95% CI 0.59 to 2.07; 7 studies, 913 participants, high certainty evidence).We found evidence that baclofen increases amount of use (drink per drinking days), (MD 1.55, 95% CI 1.32 to 1.77; 2 studies, 72 participants, low certainty evidence).Among secondary outcomes, there was no difference on craving (MD 1.38, 95% CI -1.28 to 4.03, 5 studies, 469 participants), and anxiety (SMD 0.07, 95% CI -0.14 to 0.28; 5 trials, 509 participants). We found that baclofen increased depression (SMD 0.27, 95% CI 0.05 to 0.48; 3 studies, 387 participants).Concerning the specific adverse events we found that baclofen increased: vertigo (RR 2.16, 95% CI 1.24 to 3.74; 7 studies, 858 participants), somnolence/sedation (RR 1.48, 95%CI 1.11 to 1.96; 8 studies, 946 participants), paraesthesia (RR 4.28, 95% CI 2.11 to 8.67; 4 studies, 593 participants), and muscle spasms/rigidity (RR 1.94, 95%CI 1.08 to 3.48; 3 studies, 551 participants). For all the other adverse events we did not find significant differences between baclofen and placebo.For the comparison baclofen versus acamprosate, we were only able to extract data for one outcome, craving. For this outcome, we found that baclofen increased craving compared with acamprosate (MD 14.62, 95% CI 12.72 to 16.52; 1 study, 49 participants).

AUTHORS' CONCLUSIONS

None of the primary or secondary outcomes of the review showed evidence of a difference between baclofen and placebo. The high heterogeneity among primary studies results limits the interpretation of the summary estimate, the identification of moderators and mediators of baclofen's effects on alcohol use remains a challenge for further research. Even though some results from RCTs are promising, current evidence remains uncertain regarding the use of baclofen as a first-line treatment for people with AUDs.

Baclofen in the Treatment of Patients With Alcohol Use Disorder and Other Mental Health Disorders

A limited number of medications are approved to treat Alcohol Use Disorder (AUD). Furthermore, the magnitude of their therapeutic effect is relatively modest, suggesting the potential for subtypes of patients who respond to a specific medication. The use of these medications is also limited in clinical practice by a series of contraindications such as medical comorbidities and/or concurrent use of other medications. In recent years, animal and human studies have been conducted to evaluate the efficacy of baclofen, a GABAB receptor agonist approved for clinical use as a muscle relaxant, in the treatment of AUD. However, these studies have yielded contrasting results. Despite this discrepancy, baclofen is often used off-label to treat AUD, especially in some European countries and Australia. Recently, several factors have been considered to try to shed light on the potential reasons and mechanisms underlying the inconsistent results obtained until now. The presence of a psychiatric comorbidity may be amongst the abovementioned factors playing a role in explaining different responses to baclofen treatment in terms of alcohol drinking outcomes. Therefore, the aim here was to conduct a narrative review of the scientific literature related to the use of baclofen in AUD, both in patients with and without concomitant psychiatric disorders. All clinical studies (randomized and controlled, open-label, retrospective, human laboratory studies, and case reports) were analyzed and discussed, bearing in mind other potential factors that may have influenced baclofen response, including dose administered, severity of AUD, use of other psychosocial therapies, and the presence of physical disorders. This review indicates that the most frequent psychiatric comorbidities in patients affected by AUD undergoing baclofen treatment are anxiety and mood disorders. Unfortunately, no definitive conclusions can be drawn due to the lack of specific analyses on whether baclofen efficacy is different in AUD patients with comorbid psychiatric disorders vs. those without. Therefore, it will be critical that psychiatric comorbidities are considered in the planning of future studies and in the analysis of the data, with the ultimate goal of understanding whether subtypes of AUD patients may respond best to baclofen.

Baclofen for alcohol use disorder-a systematic meta-analysis

OBJECTIVE

To evaluate the efficacy and tolerability of baclofen vs. placebo for long-term treatment of alcohol use disorder.

METHOD

Systematic review and meta-analysis following methods of the Cochrane Collaboration Handbook (PROSPERO registration: CRD42017073663). Primary outcome was the random-effects summary estimate of all standardized mean differences (SMDs), as calculated from the primary outcomes of each study.

RESULTS

Fourteen double-blind RCTs (1522 patients) were included. Heterogeneity was substantial for most analyses (I² about 75%). Baclofen showed a small, but not statistically significant superiority over placebo: SMD = 0.22 ([95% CI: -0.03; 0.47], P = 0.09). This result was supported by a leave-one-out-analysis, and Orwin's fail-safe N, by predefined secondary analyses (on abstinence rates and amount of drinking), and by a post hoc-analysis of high-dose studies (>80 mg/day). An analysis of low risk of bias studies (SMD = 0.10 [-0.20; 0.41], P = 0.51, I²  = 43.3%) found no effect. Exclusion of four studies focusing on patients with comorbidity yielded a small positive effect. Drop-out rates were similar.

CONCLUSION

Our results question baclofen's utility in the long-term treatment of alcohol use disorder at both normal and high doses. While the confidence intervals indicate that marginally harmful or moderately beneficial effects of baclofen remain a possibility, the most likely effect size is slightly above placebo effects.

Can baclofen change alcohol-related cognitive biases and what is the role of anxiety herein?

BACKGROUND

Baclofen has shown promise in the treatment of alcohol dependence. However, its precise (neuro-) psychological working mechanism is still under debate.

AIMS

This study aimed to get a better understanding of baclofen's working mechanism by examining the effect of baclofen on cognitive biases. It was hypothesized that baclofen, compared to placebo, would lead to weaker cognitive biases. Furthermore, given a suggested anxiolytic effect of baclofen, we expected that anxiety would moderate this effect.

METHODS

From a larger randomized clinical trial (RCT) with 151 participants, a subset of 143 detoxified alcohol-dependent patients, either taking baclofen or placebo, was examined. Attentional bias for alcohol (500 and 1500 ms), alcohol approach tendencies, implicit alcohol-relaxation associations and trait anxiety were assessed before the administration of baclofen or placebo. Four weeks later, 94 patients were still abstinent (53 in the baclofen and 41 in the placebo condition) and cognitive biases were assessed again.

RESULTS

At baseline, patients showed a vigilance-avoidance pattern for the attentional bias (at 500 and 1500 ms, respectively) and alcohol-negative associations. After 4 weeks, an indication for an attentional bias away from alcohol at 500 ms was found only in the baclofen group; however, cognitive biases did not differ significantly between treatment groups. No moderating role of anxiety on cognitive biases was found.

CONCLUSIONS

Baclofen did not lead to a differential change in cognitive biases compared with placebo, and trait anxiety levels did not moderate this. A better understanding of the working mechanism of baclofen and predictors of treatment success would allow prescribing of baclofen in a more targeted manner.

Baclofen: its effectiveness in reducing harmful drinking, craving, and negative mood. A meta-analysis

BACKGROUND AND AIMS

There are a limited number of pharmacotherapies licensed for alcohol use disorders (AUDs). Baclofen is a γ-aminobutyric acid B (GABA-B) agonist which is used increasingly as an off-label treatment. A meta-analysis of randomized controlled trials (RCTs) was conducted to determine the efficacy of baclofen in reducing drinking behaviour, craving, depression and anxiety compared with placebo.

METHODS

Random-effects meta-analyses were computed on outcome data from 12 RCTs comparing baclofen with placebo. Included RCTs provided data on at least one of the primary outcome measures (drinking-related: heavy drinking days, abstinent days, abstinence rates) or secondary outcome measures (craving, anxiety, depression).

RESULTS

Baclofen had a significant effect on abstinence rates when using intention-to-treat analysis [total n baclofen = 307, total n control = 283: odds ratio (OR) = 2.67, 95% confidence interval (CI) = 1.03, 6.93; Z = 2.01, P = 0.04, I²  = 76%, number needed to treat = 8]. No other significant effects of treatment efficacy [e.g. heavy drinking days: standardized mean differences (SMD) = -0.26, 95% CI = -0.68, 0.15; Z = 1.24, P = 0.21, I²  = 95%] or mechanism of action (e.g. craving: SMD = -0.13, 95% CI = -0.36, 0.09; Z = 1.18, P = 0.24, I²  = 87%) were observed. There was substantial heterogeneity in effect sizes across each analysis.

CONCLUSIONS

As a treatment for alcohol use disorders, baclofen is associated with higher rates of abstinence than placebo. However, there is no superior effect of baclofen on increasing number of abstinent days, or decreasing heavy drinking, craving, anxiety or depression. These results suggest that the current increasing use of baclofen as a treatment for alcohol use disorders is premature.

Antidepressants for the treatment of people with co-occurring depression and alcohol dependence

BACKGROUND

Alcohol dependence is a major public health problem characterized by recidivism, and medical and psychosocial complications. The co-occurrence of major depression in people entering treatment for alcohol dependence is common, and represents a risk factor for morbidity and mortality, which negatively influences treatment outcomes.

OBJECTIVES

To assess the benefits and risks of antidepressants for the treatment of people with co-occurring depression and alcohol dependence.

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Group Specialised Register (via CRSLive), Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from inception to July 2017. We also searched for ongoing and unpublished studies via ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (apps.who.int/trialsearch/).All searches included non-English language literature. We handsearched references of topic-related systematic reviews and the included studies.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials comparing antidepressants alone or in association with other drugs or psychosocial interventions (or both) versus placebo, no treatment, and other pharmacological or psychosocial interventions.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane.

MAIN RESULTS

We included 33 studies in the review (2242 participants). Antidepressants were compared to placebo (22 studies), psychotherapy (two studies), other medications (four studies), or other antidepressants (five studies). The mean duration of the trials was 9.9 weeks (range 3 to 26 weeks). Eighteen studies took place in the USA, 12 in Europe, two in Turkey, and one in Australia. The antidepressant included in most of the trials was sertraline; other medications were amitriptyline, citalopram, desipramine, doxepin, escitalopram, fluoxetine, fluvoxamine, imipramine, mianserin, mirtazepine, nefazodone, paroxetine, tianeptine, venlafaxine, and viloxazine. Eighteen studies were conducted in an outpatient setting, nine in an inpatient setting, and six in both settings. Psychosocial treatment was provided in 18 studies. There was high heterogeneity in the selection of outcomes and the rating systems used for diagnosis and outcome assessment.Comparing antidepressants to placebo, low-quality evidence suggested that antidepressants reduced the severity of depression evaluated with interviewer-rated scales at the end of trial (14 studies, 1074 participants, standardized mean difference (SMD) -0.27, 95% confidence interval (CI) -0.49 to -0.04). However, the difference became non-significant after the exclusion of studies with a high risk of bias (SMD -0.17, 95% CI -0.39 to 0.04). In addition, very low-quality evidence supported the efficacy of antidepressants in increasing the response to the treatment (10 studies, 805 participants, risk ratio (RR) 1.40, 95% Cl 1.08 to 1.82). This result became non-significant after the exclusion of studies at high risk of bias (RR 1.27, 95% CI 0.96 to 1.68). There was no difference for other relevant outcomes such as the difference between baseline and final score, evaluated using interviewer-rated scales (5 studies, 447 participants, SMD 0.15, 95% CI -0.12 to 0.42).Moderate-quality evidence found that antidepressants increased the number of participants abstinent from alcohol during the trial (7 studies, 424 participants, RR 1.71, 95% Cl 1.22 to 2.39) and reduced the number of drinks per drinking days (7 studies, 451 participants, mean difference (MD) -1.13 drinks per drinking days, 95% Cl -1.79 to -0.46). After the exclusion of studies with high risk of bias, the number of abstinent remained higher (RR 1.69, 95% CI 1.18 to 2.43) and the number of drinks per drinking days lower (MD -1.21 number of drinks per drinking days, 95% CI -1.91 to -0.51) among participants who received antidepressants compared to those who received placebo. However, other outcomes such as the rate of abstinent days did not differ between antidepressants and placebo (9 studies, 821 participants, MD 1.34, 95% Cl -1.66 to 4.34; low-quality evidence).Low-quality evidence suggested no differences between antidepressants and placebo in the number of dropouts (17 studies, 1159 participants, RR 0.98, 95% Cl 0.79 to 1.22) and adverse events as withdrawal for medical reasons (10 studies, 947 participants, RR 1.15, 95% Cl 0.65 to 2.04).There were few studies comparing one antidepressant versus another antidepressant or antidepressants versus other interventions, and these had a small sample size and were heterogeneous in terms of the types of interventions that were compared, yielding results that were not informative.

AUTHORS' CONCLUSIONS

We found low-quality evidence supporting the clinical use of antidepressants in the treatment of people with co-occurring depression and alcohol dependence. Antidepressants had positive effects on certain relevant outcomes related to depression and alcohol use but not on other relevant outcomes. Moreover, most of these positive effects were no longer significant when studies with high risk of bias were excluded. Results were limited by the large number of studies showing high or unclear risk of bias and the low number of studies comparing one antidepressant to another or antidepressants to other medication. In people with co-occurring depression and alcohol dependence, the risk of developing adverse effects appeared to be minimal, especially for the newer classes of antidepressants (such as selective serotonin reuptake inhibitors). According to these results, in people with co-occurring depression and alcohol dependence, antidepressants may be useful for the treatment of depression, alcohol dependence, or both, although the clinical relevance may be modest.

A Review of the Potential Mechanisms of Action of Baclofen in Alcohol Use Disorder

Baclofen, a GABA-B receptor agonist, is a promising treatment for alcohol use disorder (AUD). Its mechanism of action in this condition is unknown. GABA-B receptors interact with many biological systems potentially involved in AUD, including transduction pathways and neurotransmitter systems. Preclinical studies have shown that GABA-B receptors are involved in memory storage and retrieval, reward, motivation, mood and anxiety; neuroimaging studies in humans show that baclofen produces region-specific alterations in cerebral activity; GABA-B receptor activation may have neuroprotective effects; baclofen also has anti-inflammatory properties that may be of interest in the context of addiction. However, none of these biological effects fully explain the mechanism of action of baclofen in AUD. Data from clinical studies have provided a certain number of elements which may be useful for the comprehension of its mechanism of action: baclofen typically induces a state of indifference toward alcohol; the effective dose of baclofen in AUD is extremely variable from one patient to another; higher treatment doses correlate with the severity of the addiction; many of the side effects of baclofen resemble those of alcohol, raising the possibility that baclofen acts as a substitution drug; usually, however, there is no tolerance to the effects of baclofen during long-term AUD treatment. In the present article, the biological effects of baclofen are reviewed in the light of its clinical effects in AUD, assuming that, in many instances, clinical effects can be reliable indicators of underlying biological processes. In conclusion, it is proposed that baclofen may suppress the Pavlovian association between cues and rewards through an action in a critical part of the dopaminergic network (the amygdala), thereby normalizing the functional connectivity in the reward network. It is also proposed that this action of baclofen is made possible by the fact that baclofen and alcohol act on similar brain systems in certain regions of the brain.

The Use of Baclofen as a Treatment for Alcohol Use Disorder: A Clinical Practice Perspective

Alcohol use disorder (AUD) is a brain disorder associated with high rates of mortality and morbidity worldwide. Baclofen, a selective gamma-aminobutyric acid-B (GABA-B) receptor agonist, has emerged as a promising drug for AUD. The use of this drug remains controversial, in part due to uncertainty regarding dosing and efficacy, alongside concerns about safety. To date there have been 15 randomized controlled trials (RCTs) investigating the use of baclofen in AUD; three using doses over 100 mg/day. Two additional RCTs have been completed but have not yet been published. Most trials used fixed dosing of 30-80 mg/day. The other approach involved titration until the desired clinical effect was achieved, or unwanted effects emerged. The maintenance dose varies widely from 30 to more than 300 mg/day. Baclofen may be particularly advantageous in those with liver disease, due to its limited hepatic metabolism and safe profile in this population. Patients should be informed that the use of baclofen for AUD is as an "off-label" prescription, that no optimal fixed dose has been established, and that existing clinical evidence on efficacy is inconsistent. Baclofen therapy requires careful medical monitoring due to safety considerations, particularly at higher doses and in those with comorbid physical and/or psychiatric conditions. Baclofen is mostly used in some European countries and Australia, and in particular, for patients who have not benefitted from the currently used and approved medications for AUD.

Baclofen for alcohol withdrawal

BACKGROUND

Baclofen shows potential for rapidly reducing symptoms of severe alcohol withdrawal syndrome (AWS) in people with alcoholism. Treatment with baclofen is easy to manage and rarely produces euphoria or other pleasant effects, or craving for the drug. This is an updated version of the original Cochrane Review published in 2015, Issue 4.

OBJECTIVES

To assess the efficacy and safety of baclofen for people with AWS.

SEARCH METHODS

We updated our searches of the following databases to March 2017: the Cochrane Drugs and Alcohol Group Specialised Register, CENTRAL, PubMed, Embase, and CINAHL. We also searched registers of ongoing trials. We handsearched the references quoted in the identified trials, and sought information from researchers, pharmaceutical companies, and relevant trial authors about unpublished or uncompleted trials. We placed no restrictions on language.

SELECTION CRITERIA

We included all randomised controlled clinical trials (RCTs) evaluating baclofen versus placebo or any other treatment for people with AWS. We excluded uncontrolled, non-randomised, or quasi-randomised trials. We included both parallel group and cross-over studies.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included three RCTs with 141 randomised participants. We did not perform meta-analyses due to the different control interventions. For the comparison of baclofen and placebo (1 study, 31 participants), there was no significant difference in Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised (CIWA-Ar) scores (very low quality evidence). For the comparison of baclofen and diazepam (1 study, 37 participants), there was no significant difference in CIWA-Ar scores (very low quality evidence), adverse events (risk difference (RD) 0.00, 95% confidence interval (CI) -0.10 to 0.10; very low quality evidence), dropouts (RD 0.00, 95% CI -0.10 to 0.10; very low quality evidence), and dropouts due to adverse events (RD 0.00, 95% CI -0.10 to 0.10; very low quality evidence). For the comparison of baclofen and chlordiazepoxide (1 study, 60 participants), there was no significant difference in CIWA-Ar scores (mean difference (MD) 1.00, 95% CI 0.70 to 1.30; very low quality evidence), global improvement (MD 0.10, 95% CI -0.03 to 0.23; very low quality evidence), adverse events (RD 2.50, 95% CI 0.88 to 7.10; very low quality of evidence), dropouts (RD 0.00, 95% CI -0.06 to 0.06; very low quality evidence), and dropouts due to adverse events (RD 0.00, 95% CI -0.06 to 0.06; very low quality evidence).

AUTHORS' CONCLUSIONS

No conclusions can be drawn about the efficacy and safety of baclofen for the management of alcohol withdrawal because we found insufficient and very low quality evidence.

Biobehavioral effects of baclofen in anxious alcohol-dependent individuals: a randomized, double-blind, placebo-controlled, laboratory study

Baclofen has been suggested as a potential pharmacotherapy for alcohol use disorder, but the clinical data are conflicting. Here we investigated the biobehavioral effects of baclofen in a sample of anxious alcohol-dependent individuals. This was a randomized, double-blind, placebo-controlled, human laboratory study in non-treatment seeking alcohol-dependent individuals with high trait anxiety (N=34). Participants received baclofen (30 mg per day) or placebo for at least 8 days, then performed an experimental session consisting of alcohol cue-reactivity followed by alcohol administration procedure (alcohol priming, then alcohol self-administration). Total amount of alcohol self-administered was the primary outcome; alcohol craving, subjective/physiological responses and mood/anxiety symptoms were also evaluated. There was no significant medication effect on the total amount of alcohol consumed during the alcohol self-administration (P=0.76). Baclofen blunted the positive association between maximum breath alcohol concentration during priming and the amount of alcohol consumption (significant interaction, P=0.03). Ratings of feeling intoxicated were significantly higher in the baclofen group after consuming the priming drink (P=0.006). During the self-administration session, baclofen significantly increased ratings of feeling high (P=0.01) and intoxicated (P=0.01). A significant reduction in heart rate (P<0.001) and a trend-level increase in diastolic blood pressure (P=0.06) were also detected in the baclofen group during the alcohol laboratory session. In conclusion, baclofen was shown to affect subjective and physiological responses to alcohol drinking in anxious alcohol-dependent individuals. These results do not support an anti-craving or anti-reinforcing effect of baclofen, but rather suggest that baclofen may act as a substitution medication for alcohol use disorder.

Baclofen as relapse prevention in the treatment of Gamma- Hydroxybutyrate (GHB) dependence: an open label study

BACKGROUND

GHB dependence is a growing health problem in several western countries, especially the Netherlands. Attempts to stop using GHB are often followed by relapse shortly after successful detoxification. Craving for GHB use and co-morbid psychiatric symptom levels are thought to be the major factors contributing to the high relapse rates. Given its pharmacological profile, baclofen might prove an effective anti-craving agent for patients with GHB dependence. The aim of the current study is to assess the potential of baclofen as an anti-craving agent relapse prevention intervention in GHB dependent patients.

METHODS/DESIGN

In an open label non-randomized trial treatment with baclofen to a maximum of 60 mg/day will be compared with treatment as usual (TAU) in recently detoxified GHB dependent patients (n = 80). The primary outcome measure will be the level of GHB use. Secondary outcome measures are craving levels, psychiatric symptom levels and quality of life. Questionnaires will be administered during 12 weeks of baclofen treatment and at follow-up (six months after the start of treatment).

DISCUSSION

It is hypothesized that baclofen treatment compared to TAU will be associated with significantly reduced GHB use. In addition, we hypothesize that baclofen treatment will be associated with decreased craving and anxiety levels, and higher quality of life. If results are in line with our hypotheses, further studies on the efficacy of baclofen using placebo controlled designs and long term follow-up are warranted.

TRIAL REGISTRATION

The Netherlands Trial Register with number NTR4528 . Registered 19 April 2014.

Baclofen for alcohol withdrawal

BACKGROUND

The treatment baclofen shows potential for rapidly reducing symptoms of severe alcohol withdrawal syndrome (AWS) in people with alcoholism. Treatment with baclofen is easy to manage and rarely produces euphoria or other pleasant effects, or craving for the drug. This is an updated version of the original Cochrane review published in Issue 2, 2013.

OBJECTIVES

To assess the efficacy and safety of baclofen for people with AWS.

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Group Specialised Register (searched 13 January 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 1), MEDLINE (1966 to January 2015), EMBASE (1980 to January 2015), and CINAHL (1982 to January 2015). We also searched registers of ongoing trials, including ClinicalTrials.gov, the ISRCTN registry, and the European Clinical Trials Database. At the same time, we handsearched the references quoted in the identified trials, and sought information from researchers, pharmaceutical companies, and relevant trial authors about unpublished or uncompleted trials. We placed no restrictions on language.

SELECTION CRITERIA

We included all randomised controlled clinical trials (RCTs) evaluating baclofen versus placebo or any other treatment for people with AWS. We excluded uncontrolled, non-randomised, or quasi-randomised trials. We included both parallel group and cross-over studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed references retrieved for possible inclusion. Any disagreements were resolved by an independent party. We contacted study authors for additional information where needed. We collected adverse effects information from the trials.

MAIN RESULTS

Two RCTs with a total of 81 participants were eligible according to the inclusion criteria. One study suggested that both baclofen and diazepam significantly decreased the Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised (CIWA-Ar) score, without any significant difference between the two interventions. The other study showed no significant difference in CIWA-Ar score between baclofen and placebo, but a significantly decreased dependence on high-dose benzodiazepines with baclofen compared to placebo. Only one study reported on the safety of baclofen, without any side effects.

AUTHORS' CONCLUSIONS

The evidence for recommending baclofen for AWS is insufficient. We therefore need more well-designed RCTs to prove its efficacy and safety.

Pharmacotherapy for anxiety and comorbid alcohol use disorders

BACKGROUND

Anxiety disorders are a potentially disabling group of disorders that frequently co-occur with alcohol use disorders. Comorbid anxiety and alcohol use disorders are associated with poorer outcomes, and are difficult to treat with standard psychosocial interventions. In addition, improved understanding of the biological basis of the conditions has contributed to a growing interest in the use of medications for the treatment of people with both diagnoses.

OBJECTIVES

To assess the effects of pharmacotherapy for treating anxiety in people with comorbid alcohol use disorders, specifically: to provide an estimate of the overall effects of medication in improving treatment response and reducing symptom severity in the treatment of anxiety disorders in people with comorbid alcohol use disorders; to determine whether specific medications are more effective and tolerable than other medications in the treatment of particular anxiety disorders; and to identify which factors (clinical, methodological) predict response to pharmacotherapy for anxiety disorders.

SEARCH METHODS

Review authors searched the specialized registers of The Cochrane Collaboration Depression, Anxiety and Neurosis Review Group (CCDANCTR, to January 2014) and the Cochrane Drugs and Alcohol Group (CDAG, to March 2013) for eligible trials. These registers contain reports of relevant randomized controlled trials (RCT) from: the Cochrane Central Register of Controlled Trials (CENTRAL, all years), MEDLINE (1950 to date), EMBASE (1974 to date) and PsycINFO (1967 to date). Review authors ran complementary searches on EMBASE, PubMed, PsycINFO and the Alcohol and Alcohol Problems Science Database (ETOH) (to August 2013). We located unpublished trials through the National Institutes of Health (NIH) RePORTER service and the World Health Organization (WHO) International Clinical Trials Registry Platform (to August 2013). We screened reference lists of retrieved articles for additional studies.

SELECTION CRITERIA

All true RCTs of pharmacotherapy for treating anxiety disorders with comorbid alcohol use disorders. Trials assessing drugs administered for the treatment of drinking behaviour, such as naltrexone, disulfiram and acomprosate were not eligible for inclusion in this systematic review.

DATA COLLECTION AND ANALYSIS

A systematic review is a standardised evaluation of all research studies that address a particular clinical issue.Two review authors independently assessed RCTs for inclusion in the review, collated trial data and assessed trial quality. We contacted investigators to obtain missing data. We calculated categorical and continuous treatment effect estimates and their 95% confidence intervals (CI) for treatment using a random-effects model with effect-size variability expressed using Chi(2) and I(2) heterogeneity statistics.

MAIN RESULTS

We included five placebo-controlled pharmacotherapy RCTs (with 290 participants) in the review. Most of the trials provided little information on how randomization was performed or on whether both participants and study personnel were blinded to the intervention. Two of the three trials reporting superiority of medication compared with placebo on anxiety symptom outcomes were industry funded. We regarded one trial as being at high risk of bias due to selective reporting.Study participants had Diagnostic and Statistical Manual (DSM) III- and DSM IV-diagnosed alcohol use disorders and post-traumatic stress disorder (two studies), social anxiety disorder (SAD; two studies) or generalized anxiety disorder (GAD; one study). Four trials assessed the efficacy of the selective serotonin re-uptake inhibitors (SSRIs: sertraline, paroxetine); one RCT investigated the efficacy of buspirone, a 5-hydroxytryptamine (5-HT) partial agonist. Treatment duration lasted between eight and 24 weeks. Overall, 70% of participants included in the review were male.There was very low quality evidence for an effect of paroxetine on global clinical response to treatment, as assessed by the Clinical Global Impressions - Improvement scale (CGI-I). Global clinical response was observed in more than twice as many participants with paroxetine than with placebo (57.7% with paroxetine versus 25.8% with placebo; risk ratio (RR) 2.23, 95% CI 1.13 to 4.41; 2 trials, 57 participants). However, there was substantial uncertainty regarding the size of the effect of paroxetine due to the small number of studies providing data on clinically diverse patient samples. The second primary outcome measure was reduction of anxiety symptom severity. Although study investigators reported that buspirone (one trial) was superior to placebo in reducing the severity of anxiety symptoms over 12 weeks, no evidence of efficacy was observed for paroxetine (mean difference (MD) -14.70, 95% CI -33.00 to 3.60, 2 trials, 44 participants) and sertraline (one trial). Paroxetine appeared to be equally effective in reducing the severity of post-traumatic stress disorder (PTSD) symptoms as the tricyclic antidepressant desipramine in one RCT. The maximal reduction in anxiety disorder symptom severity was achieved after six weeks with paroxetine (two RCTs) and 12 weeks with buspirone (one RCT), with maintenance of medication efficacy extending to 16 with paroxetine and 24 weeks with buspirone. There was no evidence of an effect for any of the medications tested on abstinence from alcohol use or depression symptoms. There was very low quality evidence that paroxetine was well tolerated, based on drop-out due to treatment-emergent adverse effects. Nevertheless, levels of treatment discontinuation were high, with 43.1% of the participants in the studies withdrawing from medication treatment. Certain adverse effects, such as sexual problems, were commonly reported after treatment with paroxetine and sertraline.

AUTHORS' CONCLUSIONS

The evidence-base for the effectiveness of medication in treating anxiety disorders and comorbid alcohol use disorders is currently inconclusive. There was a small amount of evidence for the efficacy of medication, but this was limited and of very low quality. The majority of the data for the efficacy and tolerability of medication were for SSRIs; there were insufficient data to establish differences in treatment efficacy between medication classes or patient subgroups. There was a small amount of very low quality evidence that medication was well tolerated. There was no evidence that alcohol use was responsive to medication.Large, rigorously conducted RCTs would help supplement the small evidence-base for the efficacy and tolerability of pharmacotherapy for anxiety and comorbid alcohol use disorders. Further research on patient subgroups who may benefit from pharmacological treatment, as well as novel pharmacological interventions, is warranted.

Baclofen for the Treatment of Alcohol Dependence and Possible Role of Comorbid Anxiety

AIM

To conduct a double-blind, placebo-controlled randomized clinical trial of baclofen in the treatment of alcohol dependence.

METHODS

Out of 69 participants consecutively screened, 42 alcohol-dependent patients were randomized to receive placebo, baclofen 30 mg/day or baclofen 60 mg/day for 12 weeks. All subjects were offered BRENDA, a structured psychosocial therapy for alcohol dependence that seeks to improve motivation for change, enhance strategies to prevent relapse and encourage compliance with treatment.

RESULTS

Intention-to-treat analyses revealed that alcohol consumption (heavy drinking days, drinks per drinking day) significantly reduced across all three groups during the treatment period. There were no statistically significant advantages to treatment on time to first heavy drinking day (relapse) (P = 0.08), nor time to first drink (lapse) (P = 0.18). A post hoc analysis stratifying according to whether there had been a comorbid anxiety disorder, revealed a beneficial effect of baclofen 30 mg/day versus placebo on time to lapse and relapse (P < 0.05). There was also a beneficial effect for baclofen 60 mg/day relative to placebo on time to relapse in this comorbid group (P < 0.05). Both doses of baclofen were well tolerated. There were no serious adverse events.

CONCLUSIONS

In spite of the small sample for a 3-arm clinical trial, this study suggests a specific role of baclofen in alcohol-dependent individuals with comorbid anxiety. Replication in larger, fully-powered studies is required.

GABAB receptor ligands for the treatment of alcohol use disorder: preclinical and clinical evidence

The present paper summarizes the preclinical and clinical studies conducted to define the "anti-alcohol" pharmacological profile of the prototypic GABAB receptor agonist, baclofen, and its therapeutic potential for treatment of alcohol use disorder (AUD). Numerous studies have reported baclofen-induced suppression of alcohol drinking (including relapse- and binge-like drinking) and alcohol reinforcing, motivational, stimulating, and rewarding properties in rodents and monkeys. The majority of clinical surveys conducted to date-including case reports, retrospective chart reviews, and randomized placebo-controlled studies-suggest the ability of baclofen to suppress alcohol consumption, craving for alcohol, and alcohol withdrawal symptomatology in alcohol-dependent patients. The recent identification of a positive allosteric modulatory binding site, together with the synthesis of in vivo effective ligands, represents a novel, and likely more favorable, option for pharmacological manipulations of the GABAB receptor. Accordingly, data collected to date suggest that positive allosteric modulators of the GABAB receptor reproduce several "anti-alcohol" effects of baclofen and display a higher therapeutic index (with larger separation-in terms of doses-between "anti-alcohol" effects and sedation).

The effectiveness of pharmacological approaches in the treatment of alcohol withdrawal syndrome (AWS): a literature review

Mortality statistics for excessive alcohol consumption show no signs of abatement, with a report published in 2011 from the World Health Organization (WHO) estimating that 2.5 million people worldwide died because of their alcohol consumption. Serious physiological, psychological, social and legal problems are thought to affect many more. Alcohol withdrawal syndrome (AWS) is a potentially life-threatening condition that often occurs in those individuals who significantly reduce or stop their intake after a prolonged and excessive period of drinking. Pharmacological treatment of the AWS has traditionally been undertaken by the use of the benzodiazepines, but recent years have witnessed the emergence of several alternatives. The aim of this paper was (1) to review the evidence base supporting the use of various pharmacological agents currently employed to treat AWS, and (2) to consider the efficacy and safety of the emerging alternatives to the benzodiazepines. The Cochrane Database of Systematic Reviews, CINAHL, Embase, PsycINFO, MEDLINE and BNI databases were extensively searched in order to retrieve the maximum number of relevant articles. Reference lists from relevant literature were also used to identify other potential studies for inclusion. All studies concerned with measuring the efficacy and safety of the various pharmacological treatment options for AWS were considered and a total of 63 trials were included in this review. Findings support the use of benzodiazepines as the recommended drug of choice for the treatment of AWS in the absence of adequate evidence to support the use of alternative agents. There is a lack of evidence of a superior pharmacological agent to the benzodiazepines for the treatment of AWS. There are several studies that have shown that there are pharmacological alternatives that could compete or act as an adjunct with the benzodiazepines in terms of high efficacy and safety in the treatment of AWS, but there is a need for further quality research to be carried out before definitive conclusions can be drawn.

Clinical effectiveness of baclofen for the treatment of alcohol dependence: a review

Baclofen, an agonist at the B subunit of gaba-aminobutyric acid receptor, possesses pharmacologic properties that may confer utility for the treatment of alcohol dependence. Research suggests that not only can it be useful in promoting maintenance of alcohol abstinence but also it may play a key role in decreasing alcohol cravings and anxiety often associated with alcohol dependence. To assess the benefit of baclofen for alcohol dependence, a review of the literature was conducted to identify published data investigating this off-label treatment. Four randomized controlled trials to date have been published and were included in this review. Although primary outcomes differ between studies, patients randomized to baclofen experience higher rates of abstinence from alcohol than those taking placebo in two of the trials. Secondary analyses indicate that baclofen is safe in patients with alcohol dependence, including those with moderate to severe liver cirrhosis, and may provide beneficial anxiolytic effects. Despite some positive data, the largest available randomized controlled trial failed to find any differences between baclofen and placebo. In all studies, individuals with severe medical comorbidities, seizure disorders, and psychiatric disorders were excluded from trials, which may limit external validity. In summary, there may be beneficial effects from using baclofen for the treatment of alcohol dependence; however, limited conclusions can be drawn from the small number of studies currently available for review. Larger well-designed trials are needed to further define baclofen’s role for the treatment of alcohol dependence.

Baclofen for alcohol withdrawal

BACKGROUND

The treatment baclofen can rapidly reduce symptoms of severe alcohol withdrawal syndrome (AWS) in alcoholic patients, with a significant reduction in the cost. Baclofen is easy to manage, and rare euphoria, craving and other pleasant effects are reported by patients treated with baclofen.

OBJECTIVES

To assess the efficacy and safety of baclofen for patients with AWS.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (October 2012), MEDLINE (1966 to October 2012), EMBASE (1980 to October 2012) and CINAHL (1982 to October 2012). We also searched registers of ongoing trials, for example ClinicalTrials.gov, Controlled-trials.com, EUDRACT, etc. At the same time, we handsearched the references quoted in the identified trials, and contacted researchers, pharmaceutical companies and relevant trial authors seeking information about unpublished or uncompleted trials. All searches included the non-English language literature.

SELECTION CRITERIA

All randomized controlled clinical trials (RCTs) evaluating baclofen versus placebo or any other treatment for patients with AWS. Uncontrolled, non-randomized or quasi-randomized trials were excluded. Both parallel group and cross-over design were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed references retrieved for possible inclusion. All disagreements were resolved by an independent party. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

We identified a total of 113 references from all electronic databases searched excluding duplicates. After screening of titles and abstracts, full papers of 10 studies were obtained and assessed for eligibility. Finally, two RCTs with 81 participants were eligible according to the inclusion criteria. Regarding the efficacy, one study suggested that both baclofen and diazepam significantly decreased the Clinical Institute Withdrawal Assessment of Alcohol Scale Revised (CIWA-Ar) score, without any significant difference between the two interventions. The other study showed no significant difference in CIWA-Ar score between baclofen and placebo but a significantly decreased dependence on high-dose benzodiazepines with baclofen compared to placebo. Meanwhile, only one study reported the safety outcomes and there were no side effects in either the baclofen or diazepam groups.

AUTHORS' CONCLUSIONS

The evidence for recommending baclofen for AWS is insufficient. More well designed RCTs are needed to prove its efficacy and safety.

Efficacy and tolerability of baclofen in substance use disorders: a systematic review

BACKGROUND

It has been reported that baclofen, a drug used in the treatment of spasticity, reduces the severity of withdrawal symptoms and substance use disorders (SUDs) for some psychoactive drugs.

AIMS AND METHODS

To evaluate the effectiveness and safety of baclofen in the treatment of withdrawal syndrome and/or SUDs, providing (1) an outline of its pharmacological features; (2) a summary of studies that have suggested its possible effectiveness in the treatment of SUDs, and (3) a review of randomized, controlled trials (RCTs) on baclofen and SUDs.

RESULTS

Baclofen tolerability is generally considered to be good. Eleven RCTs investigated its effectiveness in the treatment of SUDs. Of these, 5 RCTs found that baclofen is effective, 5 RCTs found that it is ineffective and the results of 1 RCT were not appreciable because it did not achieve the preplanned level of participation.

CONCLUSIONS

The number of RCTs on baclofen and SUDs is still low, and their results are divergent. Further RCTs should be undertaken, particularly with higher doses of baclofen. Its administration may be suggested in patients who fail to respond to other approved drugs or who are affected by liver disease that prevents their administration, or in patients affected by SUDs for which no approved drugs are available. Treatment should be conducted under strict medical supervision.

Reconsidering GHB: orphan drug or new model antidepressant?

For six decades, the principal mode of action of antidepressant drugs is the inhibition of monoamine re-uptake from the synaptic cleft. Tricyclic antidepressants, selective serotonin re-uptake inhibitors (SSRIs) and the new generation of dual antidepressants all exert their antidepressant effects by this mechanism. In the early days of the monoaminergic era, other efforts have been made to ameliorate the symptoms of depression by pharmacological means. The gamma-aminobutyric acid (GABA) system was and possibly still is one of the main alternative drug targets. Gammahydroxybutyrate (GHB) was developed as an orally active GABA analogue. It was tested in animal models of depression and human studies. The effects on sleep, agitation, anhedonia and depression were promising. However, the rise of benzodiazepines and tricyclic antidepressants brought GHB out of the scope of possible treatment alternatives. GHB is a GABA(B) and GHB receptor agonist with a unique spectrum of behavioural, neuroendocrine and sleep effects, and improves daytime sleepiness in various disorders such as narcolepsy, Parkinson's disease and fibromyalgia. Although it was banned from the US market at the end of the 1990s because of its abuse and overdose potential, it later was approved for the treatment of narcolepsy. New research methods and an extended view on other neurotransmitter systems as possible treatment targets of antidepressant treatment brought GHB back to the scene. This article discusses the unique neurobiological effects of GHB, its misuse potential and possible role as a model substance for the development of novel pharmacological treatment strategies in depressive disorders.

Defining the role of baclofen for the treatment of alcohol dependence: a systematic review of the evidence

The pharmacological properties of baclofen, a GABA(B) receptor agonist, have led to investigation of its use for the off-label treatment of alcohol dependence. Literature examining the role of baclofen in alcohol dependence suggests that it may be a useful medication in the treatment armamentarium with an additional benefit of promoting abstinence and reducing alcohol-associated cravings and anxiety. We conducted a systematic review of prospective, randomized controlled trials comparing baclofen with placebo for the treatment of alcohol dependence. Four randomized controlled trials were identified but only three met criteria for inclusion. The excluded trial was a post hoc analysis of data collected from an original trial whose primary outcome did not fit our inclusion criteria and was terminated prior to completion. Compared with placebo, subjects randomized to baclofen experienced higher rates of abstinence and lower anxiety scores; the effect of baclofen was statistically significant in two trials assessing patients with more severe alcohol dependence and non-significant in a trial of outpatients receiving concomitant manualized psychotherapy. Baclofen appeared to be safe, well tolerated and to have low addiction liability even in the setting of moderate-to-severe liver cirrhosis, a known complication of alcohol dependence. Though baclofen may hold promise, the different outcomes and sample populations of the three studies highlight the need for more research to better understand the appropriate target patient population to benefit from this medication. Questions still remain about optimal dosing and duration. There is not enough evidence to support the use of baclofen as a first-line treatment option, except for those alcohol-dependent patients with moderate-to-severe liver cirrhosis in whom other pharmacological treatments are not safe or practical.

Efficacy and safety of baclofen for alcohol dependence: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Recent clinical trials and case-reports indicate that baclofen, a GABA(B) agonist, may have efficacy for alcohol dependence. Baclofen has been shown to enhance abstinence, to reduce drinking quantity, to reduce craving, and to reduce anxiety in alcohol-dependent individuals in 2 placebo-controlled trials in Italy. However, the clinical trial data with baclofen is limited. The purpose of the present study was to test the efficacy and tolerability of baclofen in alcohol dependence in the United States.

METHODS

The study was a double-blind, placebo-controlled, randomized study comparing 30 mg/d of baclofen to placebo over 12 weeks of treatment and utilizing 8 sessions of BRENDA, a low-intensity psychosocial intervention. One hundred and twenty-one subjects were screened to yield 80 randomized subjects (44 men) with randomization balanced for gender. Percent heavy drinking days was the primary outcome measure with other drinking outcomes, anxiety levels, and craving as secondary outcomes. Tolerability was examined.

RESULTS

Seventy-six percent of subjects completed the study. No difference by drug condition was seen in percentage of heavy drinking days where on-average rates were 25.5% (±23.6%) for placebo and 25.9% (±23.2%) for baclofen during treatment (t(73)=0.59, p=0.56). Similarly, no differences were seen by drug condition in percentage of days abstinent, time to first drink, or time to relapse to heavy drinking. Baclofen was associated with a significant reduction in state anxiety (F(1,73)= 5.39, p=0.02). Baclofen was well tolerated with only 2 individuals stopping baclofen because of adverse events. There were no serious adverse events.

CONCLUSIONS

Baclofen, a GABA(B) agonist, represents a possible new pharmacotherapeutic approach to alcohol dependence. Despite encouraging preclinical data and prior positive clinical trials with baclofen in Italy, the current trial did not find evidence that baclofen is superior to placebo in the treatment of alcohol dependence. Additional clinical trial work is necessary to establish whether baclofen does or does not have therapeutic efficacy in alcohol dependence and, if it does, what factors are predictive of response.

Baclofen for alcohol withdrawal

BACKGROUND

The treatment of baclofen can rapidly reduce symptoms of severe alcohol withdrawal syndrome (AWS) in alcoholic patients, with a significant reduction in the cost. Baclofen is easily manageable, what's more, no patient treated with baclofen reported euphoria or other pleasant effects caused by the drug and no subject reported any degree of craving for the drug.

OBJECTIVES

To assess the efficacy and safety of baclofen for patients with alcohol withdrawal syndrome.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (September 2010), MEDLINE (1966 to September 2010), EMBASE (1980 to September 2010), and CINAHL (1982 to September 2010). We also searched the following registers of ongoing trials, e.g. Clinicaltrials.gov, Controlled trials.com, EUDRACT, etc. At the same time, we handsearched the references quoted in the identified trials, contact researchers, pharmaceutical companies and relevant trial authors seeking information about unpublished or incomplete trials. All searches included non-English language literature.

SELECTION CRITERIA

All randomised controlled clinical trials (RCTs) evaluating baclofen versus placebo or any other treatment for patients with AWS. Uncontrolled, non-randomised or quasi-randomised trials were excluded. Both parallel group and cross-over design were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed references retrieved for possible inclusion. All disagreements were resolved by an independent party. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

We identified a total of 82 references from all electronic databases searched excluding duplicate. After screening of titles and abstracts, full papers of 7 studies were obtained and assessed for eligibility. Finally, only one study met the inclusion criteria, with 37 participants.

AUTHORS' CONCLUSIONS

The evidence of recommending baclofen for AWS is insufficient. More well designed RCTs are demanded to further prove its efficacy and safety.

The GABAB receptor agonist baclofen administered into the median and dorsal raphe nuclei is rewarding as shown by intracranial self-administration and conditioned place preference in rats

RATIONALE

The midbrain raphe regions have long been implicated in affective processes and disorders. There is increasing evidence to suggest that the median (MR) and dorsal raphe nuclei (DR) tonically inhibit reward-related processes.

OBJECTIVES

Stimulation of GABAB receptors in the midbrain raphe nuclei is known to inhibit local neurons, especially serotonergic neurons. We sought to determine if injections of the GABAB receptor agonist baclofen into the MR or DR are rewarding, using intracranial self-administration and conditioned place preference.

RESULTS

Rats quickly learned to lever press for infusions of baclofen (0.1–2.5 mM) into the MR, but not the ventral tegmental area or central linear nucleus. Rats increased lever pressing associated with intra-DR baclofen infusions, but not readily. Baclofen self-administration into the MR or DR was attenuated by coadministration of the GABAB receptor antagonist SCH 50911 (1 mM) or systemic pretreatment with the dopamine receptor antagonist SCH 23390 (0.025 mg/kg, i.p.). In addition, intra-DR and intra-MR injections of baclofen induced conditioned place preference; injection into DR was more effective.

CONCLUSIONS

Baclofen injections into the midbrain raphe nuclei are rewarding. Baclofen was more readily self-administered into the MR than into the DR, while baclofen injections into the DR more readily induced conditioned place preference than those into the MR. These sites may be differentially involved in aspects of reward. These findings suggest that MR or DR neurons containing GABAB receptors are involved in tonic inhibitory control over reward processes.

Psychosocial findings in alcohol-dependent patients before and after three months of total alcohol abstinence

Alcohol use disorders (AUDs) may be associated with several psychological and affective disorders. It is controversial, however, if these symptoms are a cause or rather a consequence of alcohol dependence. There are few data testing simultaneously psychosocial and affective disorders before and after a period of alcohol abstinence. The aim of this study was to perform multiple psychometric evaluations in alcohol-dependent patients before and after 12 weeks of abstinence. Twenty-five alcohol-dependent patients were included in the study. The following psychometric tests were administered at baseline (T0) and after 12 weeks (T1): addiction severity index (ASI), brief psychiatric rating scale (BPRS), social behavior scale (SBS), Sheehan disability scale (DISS), aggression questionnaire (AQ). At T1, 16 (64%) patients were abstinent, 5 (20%) patients dropped out and 4 (16%) patients relapsed. Compared to T0, patients totally abstinent at T1 showed a significant reduction of the scores related to BPRS, BPRS-E and its subscales (except BPRS 5), ASI 1, ASI 2, ASI 3, ASI 6, ASI 7, BSM, AQ, DISS 1, DISS 2, DISS 3 (p < 0.05). No significant changes in ASI 4, ASI 5, DISS 4, and DISS 5, BPRS 5 scores were found at T1 compared to T0. The present study indicates that total alcohol abstinence improves psychometric features, such as alcohol addiction severity, psychiatric rating, social behavior, aggressiveness, and disability. Larger controlled studies are needed to confirm these findings.

Role of the GABA(B) receptor system in alcoholism and stress: focus on clinical studies and treatment perspectives

Alcoholism and stress share some common neurobiological circuits, including the GABAergic system. In particular, the GABA(B) receptor seems to play an important role. The GABA(B) receptor agonist baclofen has been studied as a treatment for alcohol-dependent subjects. Baclofen administration in alcohol-dependent patients was able to promote abstinence, inducing the remission of withdrawal symptoms, reducing alcohol craving, and reducing alcohol intake. Baclofen also reduced anxiety in alcohol-dependent subjects, probably acting on brain stress circuitry and/or on other neuroendocrine systems. Baclofen also showed excellent safety and tolerability, even in alcohol-dependent patients with advanced liver disease (i.e., cirrhosis). Future studies should investigate which alcoholic subtype may better benefit of the administration of baclofen in the treatment of alcohol dependence.

Complete suppression of craving in alcohol-dependent individuals: is it possible?

A recent preliminary, single-case report suggested that baclofen not only reduces but may completely suppress craving in alcohol-dependent individuals. The current article summarizes the neurobiological basis of drug craving, and the pharmacological targets that have been shown to be involved in modulating such craving. The potential usefulness of agents that suppress craving is discussed. However, beyond individual case reports, no evidence is available to indicate that targeting a single neurobiological pathway will be sufficient to completely suppress craving in unselected individuals. Nevertheless, subgroups that carry specific characteristics associated with single receptor dysfunction might benefit from a targeted treatment. Further research is needed to enable clinicians to detect these subgroups.

Management of co-morbid anxiety and alcohol disorders: parallel treatment of disorders

Co-morbid alcohol-related disorders and anxiety disorders have been found to occur in alcohol treatment populations, anxiety treatment populations and the general community. People suffering from co-occurring alcohol-related and anxiety disorders are more prone to relapse to alcohol abuse, and more likely to re-enter the treatment system for either disorder than sufferers of either disorder without a co-morbid disorder. To review the current state of the management of this disorder, evidence of the prevalence of this co-morbid condition in clinical and community populations is examined, then the theoretical mechanisms that might explain this connection are reviewed. A comparison of the few treatment studies of co-morbid alcohol and anxiety disorders shows a limited number of pharmacological treatment trials and no psychotherapy outcome trials. This review shows that it is no longer sustainable to conceptualize co-morbidity of alcohol and anxiety disorders as a unitary concept, i.e. lumping alcohol-related and anxiety disorders as one global condition, but as separate distinct combinations of particular anxiety disorders, e.g. alcohol dependence and panic disorder, alcohol dependence and generalize anxiety disorder. The recommended treatment approach, supported by the evidence, is to offer separate and parallel therapy for the alcohol-related and anxiety disorder, until empirical evidence from treatment outcome studies suggest otherwise. There is an urgent need to conduct treatment outcome research for the subtypes of co-morbid alcohol and anxiety disorders.

Acute interaction of baclofen in combination with alcohol in heavy social drinkers

BACKGROUND

There is growing evidence that gamma-amino butyric acid-B receptor agonists may be effective in the treatment of alcohol abuse or dependence. The primary goal of this study was to determine the safety of baclofen in combination with alcohol consumption in heavy drinkers. In addition, the effects of baclofen alone, and in combination with alcohol, on subjective effects, cognitive performance effects, as well as alcohol craving, were assessed.

METHODS

Eighteen non-treatment-seeking heavy social drinkers (mean of 28 drinks per week), who did not meet the criteria for alcohol dependence participated. All individuals were tested using a double-blind double-dummy design with six 2-day inpatient phases. Baclofen (0, 40, and 80 mg) was administered 2.5 hours before alcohol (1.5 g/l body water or approximately 0.75 g/kg) or placebo beverages, given in 4 divided doses every 20 minutes.

RESULTS

Baclofen, either alone or in combination with alcohol, produced only modest increases in heart rate and blood pressure and no adverse effects were reported. Baclofen did not increase positive subjective effects (e.g., Stimulant effects, Drug Liking) but did increase sedation and impair performance. Even though both baclofen and alcohol impaired performance, for the most part performance was not impaired to a greater extent when baclofen was combined with alcohol. Among this population of nondependent drinkers, baclofen did not alter alcohol craving or alcohol-induced positive subjective effects.

CONCLUSIONS

Baclofen alone has minimal abuse liability in heavy social drinkers, and baclofen is relatively well tolerated and safe when given in combination with intoxicating doses of alcohol.