A preliminary double-blind, placebo-controlled randomized study of baclofen effects in alcoholic smokers

The use of baclofen to reduce alcohol-attributable hospitalizations and emergency department admissions

AIMS

The potential benefit of baclofen in reducing hospitalizations and emergency department (ED) admissions attributed to alcohol-related diagnoses has not been conclusively established. This study aimed to examine the relationship between baclofen use and the incidence of alcohol-attributable hospitalizations and ED admissions in the general population.

METHODS

We conducted a self-controlled case series study (SCCS) using data from the Taiwan National Health Insurance Research Database. 2904 patients who had at least one alcohol-attributable hospitalization or emergency department admission and were prescribed 28 or more days of baclofen unrelated to alcohol were included. Conditional Poisson regression was used to estimate the incidence rate ratio (IRR) and 95% confidence interval (CI) for the risk of alcohol-attributable hospitalizations and ED admissions during exposure to baclofen, as well as the pre- and post-exposure periods, relative to the baseline period. The contribution of concomitant psychotropic medication use was also assessed.

RESULTS

Baclofen was associated with a reduced incidence of alcohol-attributable hospitalizations (IRR = 0.64; 95% CI: 0.53∼0.77) and ED admissions (IRR = 0.56; 95% CI: 0.49∼0.65) in multivariate models. No statistically significant reduction was observed in any admission method in either the pre- or post-exposure period. A dose-dependent response in ED admissions was observed with baclofen, i.e. >60 mg/day associated with a greater decrease in the IRR (0.25, 95% CI: 0.10∼0.62) relative to doses of <30 (0.63, 95% CI: 0.53∼0.75) and 30-60 mg/day (IRR = 0.50, 95% CI: 0.40∼0.63).

CONCLUSIONS

These findings suggest a possible beneficial effect of baclofen in reducing the incidence of alcohol-attributable hospitalizations and ED admissions.

Effects of a novel GABA-B positive allosteric modulator, ASP8062, on alcohol cue-elicited craving and naturalistic alcohol consumption in a multisite randomized, double-blind, placebo-controlled trial

BACKGROUND

The γ-aminobutyric acid-B (GABAB) receptor is a promising target for the development of new medications to treat alcohol use disorder (AUD). The GABAB agonist baclofen has been reported to reduce alcohol consumption but is associated with some undesirable side effects, including sedation. ASP8062 is a novel compound that acts as a positive allosteric modulator at the GABAB receptor and may be more tolerable than baclofen. This proof-of-concept human laboratory clinical trial evaluated the safety profile of ASP8062 and tested its effects on cue-elicited alcohol craving and alcohol use among treatment-seeking individuals with AUD.

METHODS

This double-blind, randomized, multisite trial tested the effect of ASP8062 (25 mg once daily), relative to placebo, on alcohol cue-elicited craving in a laboratory setting and alcohol consumption, craving, mood, sleep, cigarette smoking, and alcohol-related consequences in the natural environment over a 6-week treatment period. Participants were 60 individuals (26 females and 34 males) with moderate or severe AUD.

RESULTS

ASP8062, relative to placebo, was well tolerated, and there were no adverse events (AEs) that significantly differed between treatment groups. Most AEs were mild/moderate, and there were no serious AEs among individuals treated with ASP8062. However, ASP8062 did not attenuate alcohol cue-elicited craving compared with placebo. Moreover, exploratory analyses indicated that ASP8062, relative to placebo, did not significantly affect alcohol consumption, naturalistic alcohol craving, mood, sleep, cigarette smoking, or alcohol-related negative consequences during the 6-week treatment period.

CONCLUSIONS

Although ASP8062 was well tolerated with no serious AEs, the novel compound did not significantly dampen alcohol cue-elicited craving or improve other AUD-related outcome measures. These data indicate positive allosteric modulation of the GABAB receptor at the dose evaluated here may not blunt alcohol cue-elicited craving, and preliminary drinking outcome data suggest it may not be an efficacious treatment strategy for AUD.

Efficacy of medications for the treatment of alcohol use disorder (AUD): A systematic review and meta-analysis considering baseline AUD severity

Baseline severity of alcohol use disorder (AUD) is an influencing factor in the response to medications recommended for the treatment of AUD. The scarce efficacy of AUD medications partly justifies their limited uses. We were interested in evaluating the efficacy of approved and recommended AUD medications using generic inverse-variance, an analysis facilitating comparison between medications and placebo both at the end of the study and, concomitantly, to baseline values for the same participants. We conducted a systematic review to include randomized controlled trials (RCTs) comparing any medication to placebo providing, both at baseline and end of treatment, percent heavy drinking days (%HDD), percent drinking days (%DD), and/or drinks per drinking day (DDD). We searched PubMed, Embase, PMC, and three CT registers from inception to April 2023. A total of 79 RCTs (11,737 AUD participants; 30 different medications) were included: 47 RCTs (8465 participants) used AUD medications, and 32 RCTs (3272 participants) used other medications. At baseline, participants consumed on average approximately 12 DDD, and experienced 70 % DD, and 61 % HDD. Placebo halved or reduced these values to a third. Compared to placebo, AUD medications further reduced these outcomes (moderate to high certainty evidence). Other medications reduced the DDD without modifying other alcohol outcomes. AUD medications increased the risk of developing adverse events (high-certainty evidence). Despite the large placebo effects, our results support the benefits of providing AUD medications to people with AUD, helping them reduce alcohol consumption.

Baclofen in the treatment of alcohol use disorder: tailored doses matter

AIMS

To address the question of tailored baclofen prescribing in alcohol use disorder (AUD) in relation to dose-dependent efficacy and the potential danger of high doses and to provide suggestions for the use of high doses of baclofen in the treatment of AUD. The context is the approvement in France of baclofen in the treatment of AUD without dose limitation, making French physicians, who usually prescribe baclofen in a tailored manner, often use high or very high doses.

METHODS

A narrative review of the results of randomized controlled trials (RCTs) and observational studies that used tailored baclofen prescribing and of the severe adverse effects of baclofen that have been reported in the literature.

RESULTS

The results show that RCTs using tailored doses of baclofen in AUD are not completely demonstrative, though they are encouraging according to certain meta-analyses, while observational studies that used tailored doses constantly show a good effectiveness of baclofen treatment. The results suggest that many severe adverse effects of baclofen could be related to a nonrespect by physicians of prescription rules and appropriate treatment monitoring.

CONCLUSIONS

The use of tailored doses shows that the dose required to suppress cravings is highly variable, low or high, depending on each case. Analysis of the circumstances in which severe adverse effects occur suggest that a careful monitoring of baclofen prescribing might prevent a large majority of severe adverse effects. We propose that the education of the patients and the prescription skills, seriousness, and availability of the prescribing physicians are of major importance in the managing of tailored baclofen treatment of AUD.

Testing pharmacotherapies for alcohol use disorder with cue exposure paradigms: A systematic review and quantitative synthesis of human laboratory trial methodology

Alcohol cue exposure is a widely used experimental paradigm for screening pharmacotherapies for alcohol use disorder (AUD). Medication-related reductions in cue-reactivity signal early efficacy and inform medications development. Yet, across trials, the design of cue exposure, parameter testing, and outcome reporting is heterogeneous. This systematic review is a quantitative synthesis of trial methodologies and effect size estimation for AUD medication-related craving and psychophysiological outcomes under the cue exposure paradigm. A PubMed search was conducted on January 3, 2022 based on identified pharmacotherapies for peer-reviewed articles reported in English. Study-level characteristics, including sample descriptors, paradigm design, analytic approach, and Cochrane Risk of Bias, along with descriptive statistics for cue-exposure outcomes, were coded by two independent raters. Study-level effect sizes were estimated for craving and psychophysiological outcomes separately and sample-level effect sizes were calculated for each medication. Thirty-six trials, comprising 1640 participants and testing 19 different medications satisfied eligibility criteria. All studies reported on biological sex (71% male participants on average). The exposure paradigms implemented used in vivo (n = 26), visual (n = 8), and audio script (n = 2) cues. Some trials included means for craving by medication condition in text (k = 7) or figures (k = 18). The quantitative synthesis included 63 effect sizes (craving kes  = 47; psychophysiological kes  = 16) from 28 unique randomized trials testing 15 medications for effects on cue reactivity. For cue-induced craving, eight medications (kes range: 1-12) demonstrated small-to-medium effects (Cohen's d range: |0.24-0.64|) compared to placebo, with individuals randomized to receive medication reporting lower craving following cue exposure. Recommendations are provided to promote further consilience, so that the utility of cue exposure paradigms can be maximized in the development of effective AUD pharmacotherapies. Future work should explore the predictive utility of medication-related reductions in cue-reactivity on clinical outcomes.

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.

Incidence and Progression of Alcohol-Associated Liver Disease After Medical Therapy for Alcohol Use Disorder

IMPORTANCE

Alcohol-associated liver disease (ALD) is one of the most devastating complications of alcohol use disorder (AUD), an increasingly prevalent condition. Medical addiction therapy for AUD may play a role in protecting against the development and progression of ALD.

OBJECTIVE

To ascertain whether medical addiction therapy was associated with an altered risk of developing ALD in patients with AUD.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used the Mass General Brigham Biobank, an ongoing research initiative that had recruited 127 480 patients between its start in 2010 and August 17, 2021, when data for the present study were retrieved. The mean follow-up duration from AUD diagnosis was 9.2 years. International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnosis codes were used to identify ALD and AUD diagnoses.

EXPOSURES

Medical addiction therapy was defined as the documented use of disulfiram, acamprosate, naltrexone, gabapentin, topiramate, or baclofen. Patients were considered to be treated if they initiated medical addiction therapy before the relevant outcome.

MAIN OUTCOMES AND MEASURES

Adjusted odds ratios (aORs) for the development of ALD and hepatic decompensation were calculated and adjusted for multiple risk factors.

RESULTS

The cohort comprised 9635 patients with AUD, of whom 5821 were male individuals (60.4%), and the mean (SD) age was 54.8 (16.5) years. A total of 1135 patients (11.8%) had ALD and 3906 patients (40.5%) were treated with medical addiction therapy. In multivariable analyses, medical addiction therapy for AUD was associated with decreased incidence of ALD (aOR, 0.37; 95% CI, 0.31-0.43; P < .001). This association was evident for naltrexone (aOR, 0.67; 95% CI, 0.46-0.95; P = .03), gabapentin (aOR, 0.36; 95% CI, 0.30-0.43; P < .001), topiramate (aOR, 0.47; 95% CI, 0.32-0.66; P < .001), and baclofen (aOR, 0.57; 95% CI, 0.36-0.88; P = .01). In addition, pharmacotherapy for AUD was associated with lower incidence of hepatic decompensation in patients with cirrhosis (aOR, 0.35; 95% CI, 0.23-0.53, P < .001), including naltrexone (aOR, 0.27; 95% CI, 0.10-0.64; P = .005) and gabapentin (aOR, 0.36; 95% CI, 0.23-0.56; P < .001). This association persisted even when medical addiction therapy was initiated only after the diagnosis of cirrhosis (aOR, 0.41; 95% CI, 0.23-0.71; P = .002).

CONCLUSIONS AND RELEVANCE

Results of this study showed that receipt of medical addiction therapy for AUD was associated with reduced incidence and progression of ALD. The associations of individual pharmacotherapy with the outcomes of ALD and hepatic decompensation varied widely.

Efficacy and tolerability of baclofen in a U.S. community population with alcohol use disorder: a dose-response, randomized, controlled trial

Identification of new medications for alcohol use disorder (AUD) is important for improving treatment options. Baclofen, a GABA_B agonist, has been identified as a potential pharmacotherapy for AUD. In a 16-week double-blind, randomized, placebo-controlled trial, we investigated 30 and 90 mg/day of baclofen compared to placebo and examined effects of dose, sex, and level of pretreatment drinking. One hundred and twenty participants with DSM-IV alcohol dependence (age 46.1 (sd = 10.1) years, 51.7% male) were randomized after exclusion for unstable medical/psychiatric illness and/or dependence on drugs other than nicotine. Seventy-three participants completed the trial. A main effect of baclofen was found [%HDD (F(2,112) = 4.16, p = 0.018, d = 0.51 95%CI (0.06-0.95), 13.6 fewer HDD) and %ABST (F(2,112) = 3.68, p = 0.028, d = 0.49 95%CI (0.04-0.93), 12.9 more abstinent days)] and was driven by the 90 mg/day dose. A sex × dose interaction effect was present for both %HDD (F(2,110) = 5.48, p = 0.005) and %ABST (F(2,110) = 3.19, p = 0.045). Men showed a marginally positive effect for 90 mg/day compared to PBO (%HDD t(110) = 1.88, p = 0.063, d = 0.36 95%CI (-0.09-0.80), 15.8 fewer HDD days; %ABST t(110) = 1.68 (p = 0.096, d = 0.32 95%CI (-0.12-0.76), 15.7 more ABST)) with no effect for 30 mg/day. Women showed a positive effect for 30 mg/day (%HDD, t(110) = 3.19, p = 0.002, d = 0.61 95%CI (0.16-1.05), 26.3 fewer HDD days; %ABST t(110) = 2.73, p = 0.007, d = 0.52 95%CI (0.07-0.96), 25.4 more ABST days) with marginal effects for 90 mg/day on %ABST (p = 0.06) with drop-outs/dose reduction from sedative side-effects of 59% in women at 90 mg/day compared to 5% for men. These findings support the hypothesis that baclofen has efficacy in AUD and suggest that dose and sex be further explored as potential moderators of baclofen response and tolerability.

Alcohol-related changes in behaviors and characteristics from the baseline to the randomization session for treatment and non-treatment seeking participants with alcohol use disorder

BACKGROUND

Participants who are enrolled in randomized controlled trials (RCTs) may be more motivated to change their behaviors after being enrolled in a study and that motivation may vary by treatment status.

OBJECTIVES

The objectives of this secondary analysis were to investigate if changes in alcohol-related behaviors/characteristics from the baseline to the randomization session differed overall and to assess those differences between non-treatment and treatment seeking individuals with alcohol use disorder (AUD).

METHODS

Our sample included participants from eight RCTs conducted at Brown University (N = 281, 34% female). To assess differences across alcohol-related behaviors/characteristics, we investigated changes in craving (obsessive compulsive drinking scale) and alcohol drinking (percent abstinent days, drinks per week (DPW) and percent heavy drinking days (HDD)) overall and between treatment status.

RESULTS

Results showed that there were baseline differences, such as increased AUD severity and craving for alcohol in treatment seeking participants (p's < .05) in the overall sample. Next, we showed that craving, DPW and HDD decreased and percent abstinent days increased from baseline to randomization (p's < .05). When controlling for treatment status and sociodemographic characteristics, treatment seeking, compared to non-treatment seeking participants, had a greater reduction in alcohol craving (p < .001) and a greater increase in percentage of drinking days (p < .01).

CONCLUSIONS

These findings demonstrated that alcohol-related behaviors and characteristics changed after enrollment. Severity, craving and drinking behaviors also differed between treatment-seeking status, which can potentially impact medication development stages for AUD such as clinical trial eligibility, enrollment and study outcomes.

A deeper insight into how GABA-B receptor agonism via baclofen may affect alcohol seeking and consumption: lessons learned from a human laboratory investigation

Previous studies suggest that GABA-B receptor agonism may represent an effective pharmacological approach to treat addictive disorders. Baclofen is a selective GABA-B receptor agonist which has been investigated as a potential treatment for alcohol use disorder. However, research is needed to understand the biobehavioral mechanisms underlying baclofen's effect on alcohol use. In the present randomized, double-blind, placebo-controlled study, thirty-four alcohol-dependent individuals were randomized to receive baclofen (30 mg/d) or placebo for a week, and then participated in a laboratory experiment consisting of three procedures: alcohol cue-reactivity, priming, and self-administration. During the experiment, craving and other subjective responses to alcohol were assessed, and blood samples were collected for pharmacokinetic measurements. The effects of baclofen on the relationships between different alcohol-related laboratory parameters were investigated. Baclofen pharmacokinetic parameters and their correlations with behavioral measures were also examined. Results showed that baclofen disrupted the link between alcohol priming and self-administration, as indicated by significant interaction effects between drug condition (baclofen vs. placebo) and some of the priming variables (alcohol craving: F3,9 = 6.03, p = 0.01; alcohol sedation: F3,6 = 7.16, p = 0.01) on the total amount of alcohol self-administered. Considerable interindividual variability in baclofen pharmacokinetic parameters was observed. Maximum plasma concentrations of baclofen negatively correlated with cue-induced alcohol craving (r = -0.57, p = 0.03) and priming-induced ratings of 'like more' (r = -0.59, p = 0.02). In conclusion, baclofen may work by dissociating the link between an initial drink (priming) and subsequent alcohol consumption (self-administration). Considerable pharmacokinetic variability is an important factor to take into account when employing baclofen as a treatment for alcohol use disorder.

Brief Report: Relationship Between Cotinine Levels and Peripheral Endogenous Concentrations of Oxytocin, β-Endorphin, and Orexin in Individuals With Both Alcohol and Nicotine Use Disorders

BACKGROUND AND OBJECTIVES

In this secondary analysis of a pilot clinical trial with individuals with alcohol and nicotine use disorders, we investigate the relationship between serum concentrations of oxytocin, β-endorphin, melatonin, α-melanocyte-stimulating hormone, substance P, and orexin, with objective biomarkers (salivary cotinine and serum γ-glutamyl transferase [GGT]) as well as with self-reported smoking and alcohol drinking.

METHODS

Biomarkers for a total of N = 19 participants were analyzed using multiplexed, competitive format immune-assay (peptides) and enzyme competitive immunoassay (saliva). A regression analysis using Pearson's correlation coefficient was utilized to determine correlations. We controlled for multiple comparisons, checked for collinearities, and ran two-sided statistical tests.

RESULTS

We found significant positive correlations for cotinine and oxytocin (P = .002), β-endorphin (P = .008), and orexin (P < .001), but not for either GGT or self-reported smoking or alcohol drinking.

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

These preliminary results suggest a relationship between cotinine and oxytocin, β-endorphin, and orexin, which opens up new potential hypotheses on the potential role of these endocrine pathways in tobacco smokers. (Am J Addict 2021;30:88-91).

Baclofen-induced Changes in the Resting Brain Modulate Smoking Cue Reactivity: A Double-blind Placebo-controlled Functional Magnetic Resonance Imaging Study in Cigarette Smokers

Objective

Smoking cue-(SC) elicited craving can lead to relapse in SC-vulnerable individuals. Thus, identifying treatments that target SC-elicited craving is a top research priority. Reduced drug cue neural activity is associated with recovery and is marked by a profile of greater tonic (resting) activation in executive control regions, and increased connectivity between executive and salience regions. Evidence suggests the GABA-B agonist baclofen can reduce drug cue-elicited neural activity, potentially through its actions on the resting brain. Based on the literature, we hypothesize that baclofen’s effects in the resting brain can predict its effects during SC exposure.

Methods

In this longitudinal, double blind, placebo-controlled neuropharmacological study 43 non-abstinent, sated treatment-seeking cigarette smokers (63% male) participated in an fMRI resting-state scan and a SC-reactivity task prior to (T1) and 3 weeks following randomization (T2; baclofen: 80 mg/day; n = 21). Subjective craving reports were acquired before and after SC exposure to explicitly examine SC-induced craving.

Results

Whole-brain full-factorial analysis revealed a group-by-time interaction with greater resting brain activation of the right dorsolateral prefrontal cortex (dlPFC) at T2 in the baclofen group (BAC) (p_FWEcorr = 0.02), which was associated with reduced neural responses to SCs in key cue-reactive brain regions; the anterior ventral insula and ventromedial prefrontal cortex (p_FWEcorr < 0.01). BAC, but not the placebo group reported decreased SC-elicited craving (p = 0.02).

Conclusion

Results suggest that baclofen mitigates the reward response to SCs through an increase in tonic activation of the dlPFC, an executive control region. Through these mechanisms, baclofen may offer SC-vulnerable smokers protection from SC-induced relapse.

The novel ghrelin receptor inverse agonist PF-5190457 administered with alcohol: preclinical safety experiments and a phase 1b human laboratory study

Rodent studies indicate that ghrelin receptor blockade reduces alcohol consumption. However, no ghrelin receptor blockers have been administered to heavy alcohol drinking individuals. Therefore, we evaluated the safety, tolerability, pharmacokinetic (PK), pharmacodynamic (PD) and behavioral effects of a novel ghrelin receptor inverse agonist, PF-5190457, when co-administered with alcohol. We tested the effects of PF-5190457 combined with alcohol on locomotor activity, loss-of-righting reflex (a measure of alcohol sedative actions), and on blood PF-5190457 concentrations in rats. Then, we performed a single-blind, placebo-controlled, within-subject human study with PF-5190457 (placebo/0 mg b.i.d., 50 mg b.i.d., 100 mg b.i.d.). Twelve heavy drinkers during three identical visits completed an alcohol administration session, subjective assessments, and an alcohol cue-reactivity procedure, and gave blood samples for PK/PD testing. In rats, PF-5190457 did not interact with the effects of alcohol on locomotor activity or loss-of-righting reflex. Alcohol did not affect blood PF-5190457 concentrations. In humans, all adverse events were mild or moderate and did not require discontinuation or dose reductions. Drug dose did not alter alcohol concentration or elimination, alcohol-induced stimulation or sedation, or mood during alcohol administration. Potential PD markers of PF-5190457 were acyl-to-total ghrelin ratio and insulin-like growth factor-1. PF-5190457 (100 mg b.i.d.) reduced alcohol craving during the cue-reactivity procedure. This study provides the first translational evidence of safety and tolerability of the ghrelin receptor inverse agonist PF-5190457 when co-administered with alcohol. PK/PD/behavioral findings support continued research of PF-5190457 as a potential pharmacological agent to treat alcohol use disorder.

Opioid Craving in Human Laboratory Settings: a Review of the Challenges and Limitations

There are many factors that need to be taken into consideration when measuring craving in a human laboratory study. This review summarizes and discusses some of the major challenges researchers are faced with when assessing opioid craving in clinical research. First, there are wide range of available assessments that have been developed for measuring craving and depending on the research questions or the underlying constructs targeted, some may be more appropriate than others. In addition to establishing the methodological point of departure for designing a study with craving, there are also different participant conditions and characteristics that need to be evaluated when selecting among the large selection of assessments available. Participant conditions/characteristics can influence the degree or frequency of opioid craving experienced. Lastly, there can be contextual conditions that affect opioid cravings such as a stressful environment that may alter cue saliency. It is recommended that researchers carefully consider the different constituents that contribute to opioid craving and to ensure a comprehensive evaluation when assessing each participant. A more thorough consideration of these challenges can help us to understand the optimal ways to measure one important and complex component of addiction.

Multisensory Environments to Measure Craving During Functional Magnetic Resonance Imaging

There are limited functional magnetic resonance imaging (fMRI) studies that measure alcohol craving with multisensory environments. Researchers are faced with a two-fold challenge: to recreate a naturalistic environment during an MRI scan and to produce paradigms that mimic real-life conditions involved with craving. Craving is a multifaceted psychological construct and techniques such as fMRI provide an alternative way to measure craving and to have a better understanding of its complexity. Most studies to date have implemented visual stimuli to measure craving and only a few studies have investigated gustation and olfaction. Moving forward, there needs to be greater attention on the ways in which we measure craving and the use of multisensory environments during fMRI. By going beyond examining subjective craving responses, and investigating neurobiological responses such as brain activity during fMRI, can potentially lead to better treatments for alcohol use disorder. Further, there needs to be additional consideration on standardizing how we measure craving, which will allow for a more unified approach amongst researchers.

Can the use of varenicline improve the efficacy of pharmacotherapy for nicotine addiction?

Introduction: Smoking is a huge medical and social problem in Poland, with as many as about 24% of Poles being addicted to nicotine. Approximately 6 million people worldwide die every year from conditions that are closely related to tobacco addiction, such as cancer and cardiovascular, metabolic or lung diseases. The difficulty in combatting nicotine dependence is largely due to the complex mechanism of this addiction. The motivation of a patient to quit smoking is of great importance in the difficult withdrawal process. Strengthening this motivation is one of the most important tasks of physicians and addiction therapists.

Overview of literature: Nicotine replacement therapy (NRT) has been the most widely known way to break away from smoking addiction for many years now. It involves delivering nicotine to the body in ways that are less harmful than through tobacco smoke. As a consequence, the cravings for nicotine are reduced, making it easier for the patient to break with the addiction. Clinical trials have shown that the use of NRT is associated with a 50-70% increased chance of maintaining abstinence from smoking compared to placebo. There are many NRT products, including nicotine chewing gum, nicotine patches, lozenges, dissolvable nicotine sticks, or inhalers. Bupropion is a selective dopamine–noradrenaline reuptake inhibitor. This drug is one of the most commonly used in the pharmacotherapy of depression in the United States. At the same time, it has been found to have a positive effect on people trying to break up with the habit of smoking cigarettes. The mechanism of action remains unknown in this case, but studies clearly indicate the efficacy of bupropion, which is comparable to the efficacy of NRT. Varenicline is a partial agonist selective for α4β2 nicotinic acetylcholine receptors. It has a higher affinity for these receptors than nicotine. By stimulating them, it causes an increase in dopamine secretion (but to a lesser extent than cigarette smoking), helping in this way ease withdrawal symptoms.

Conclusions: Varenicline has higher efficacy than bupropion and NRTs. Simultaneous use of two NRT forms increases the effectiveness of this method to a level comparable to varenicline. Contrary to previous reports, it seems that varenicline does not increase self-aggressive behaviour and the risk of suicide. The effectiveness of antinicotinic drugs depends on the sex of the patient. For both sexes, the most effective drug is varenicline. It is slightly more effective in women than in men. By contrast, NRT and bupropion show greater therapeutic potential in men.

Medication Development for Alcohol Use Disorder: A Focus on Clinical Studies

Compared to other medical disorders, including other brain diseases, the number of medications approved for alcohol use disorder (AUD) is very small. Disulfiram, naltrexone (oral and long-acting), and acamprosate are approved by the US Food and Drug Administration (FDA) to treat patients with AUD. These medications are also approved in other countries, including in Europe, where the European Medicines Agency (EMA) also approved nalmefene for AUD. Furthermore, baclofen was recently approved for AUD in France. These approved medications have small effect sizes, which are probably the consequence of the fact that they only work for some patients, yet a personalized approach to match the right medication with the right patient is still in its infancy. Therefore, research is needed to expand the armamentarium of medications that clinicians can use to treat their patients, as well as to better develop personalized approaches. This book chapter reviews other medications, beyond those approved by the FDA, that have shown efficacy in clinical trials, as well as medications which are still in the early stages of evaluation in human studies.

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.

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.

Efficacy, tolerability, and safety of low-dose and high-dose baclofen in the treatment of alcohol dependence: A systematic review and meta-analysis

A systematic review of the current literature on the efficacy of baclofen, particularly the effect of dosing, for the treatment of alcohol dependence (AD) is missing. We therefore conducted a systematic review and meta-analysis of currently available randomized placebo-controlled trials (RCTs). A systematic literature search for RCTs in AD patients comparing baclofen to placebo was performed in September 2017. The effect of baclofen treatment, and the moderating effects of baclofen dosing (low-dose (LDB) 30-60 mg versus high-dose (HDB) targeted as >60 mg/day), and the amount of alcohol consumption before inclusion were studied. Three treatment outcomes were assessed: time to lapse (TTL), percentage days abstinent (PDA), and percentage of patients abstinent at end point (PAE). 13 RCTs from 39 records were included. Baclofen was superior to placebo with significant increases in TTL (8 RCTs, 852 patients; SMD=0.42; 95% CI 0.19-0.64) and PAE (8 RCTs, 1244 patients; OR=1.93; 95% CI 1.17-3.17), and a non-significant increase in PDA (7 RCTs, 457 patients; SMD=0.21; 95% CI -0.24 to 0.66). Overall, studies with LDB showed better efficacy than studies with HDB. Furthermore, tolerability of HDB was low, but serious adverse events were rare. Meta-regression analysis showed that the effects of baclofen were stronger when daily alcohol consumption before inclusion was higher. Baclofen seems to be effective in the treatment of AD, especially among heavy drinkers. HDB is not necessarily more effective than LDB with low tolerability of HDB being an import limitation.

Cognitive effects of labeled addictolytic medications

INTRODUCTION

Alcohol, tobacco, and illegal drug usage is pervasive throughout the world, and abuse of these substances is a major contributor to the global disease burden. Many pharmacotherapies have been developed over the last 50years to target addictive disorders. While the efficacy of these pharmacotherapies is largely recognized, their cognitive impact is less known. However, all substance abuse disorders are known to promote cognitive disorders like executive dysfunction and memory impairment. These impairments are critical for the maintenance of addictive behaviors and impede cognitive behavioral therapies that are regularly administered in association with pharmacotherapies. It is also unknown if addictolytic medications have an impact on preexisting cognitive disorders, and if this impact is modulated by the indication of prescription, i.e. abstinence, reduction or substitution, or by the specific action of the medication.

METHOD

We reviewed the cognitive effects of labeled medications for tobacco addiction (varenicline, bupropion, nicotine patch and nicotine gums), alcohol addiction (naltrexone, nalmefene, baclofen, disulfiram, sodium oxybate, acamprosate), and opioid addiction (methadone, buprenorphine) in human studies. Studies were selected following MOOSE guidelines for systematic reviews of observational studies, using the keywords [Cognition] and [Cognitive disorders] and [treatment] for each medication.

RESULTS

971 articles were screened and 77 studies met the inclusion criteria and were reported in this review (for alcohol abuse, n=21, for tobacco n=22, for opioid n=34. However, very few comparative clinical trials have explored the chronic effects of addictolytic medications on cognition in addictive behaviors, and there are no clinical trials on the cognitive impact of nalmefene in patients suffering from alcohol use disorders.

DISCUSSION

Although some medications seem to enhance cognition in patients suffering from cognitive disorders, others could promote cognitive impairments, and our work highlights a lack of literature on this subject. In conclusion, more comparative clinical trials are needed to better understand the cognitive impact of addictolytic medications.

Advances in Pharmacotherapy Development: Human Clinical Studies

For more than 25 years, researchers have made advances in developing medications to treat alcohol use disorder (AUD), highlighted by the US Food and Drug Administration's (FDA's) approval of disulfiram, naltrexone (oral and long-acting), and acamprosate. These medications are also approved in Europe, where the European Medicines Agency (EMA) recently added a fourth medication, nalmefene, for AUD. Despite these advances, today's medications have a small effect size, showing efficacy for only a limited number of individuals with AUD. However, a host of new medications, which act on variety of pharmacologic targets, are in the pipeline and have been evaluated in numerous human studies. This article reviews the efficacy and safety of medications currently being tested in human trials and looks at ongoing efforts to identify candidate compounds in human studies. As mentioned in the National Institute on Alcohol Abuse and Alcoholism's Strategic Plan 2017-2021 ( https://www.niaaa.nih.gov/sites/default/files/StrategicPlan_NIAAA_optimized_2017-2020.pdf ), medications development remains a high priority. By developing more effective and safe medications, and identifying those patients who will benefit the most from these treatments, we can provide clinicians with the tools they need to treat this devastating disorder, providing relief for patients and their families and markedly improving public health and safety.

Advancing Pharmacotherapy Development from Preclinical Animal Studies

Animal models provide rapid, inexpensive assessments of an investigational drug's therapeutic potential. Ideally, they support the plausibility of therapeutic efficacy and provide a rationale for further investigation. Here, I discuss how the absence of clear effective-ineffective categories for alcohol use disorder (AUD) medications and biases in the clinical and preclinical literature affect the development of predictive preclinical alcohol dependence (AD) models. Invoking the analogical argument concept from the philosophy of science field, I discuss how models of excessive alcohol drinking support the plausibility of clinical pharmacotherapy effects. Even though these models are not likely be completely discriminative, they are sensitive to clinically effective medications and have revealed dozens of novel medication targets. In that context, I discuss recent preclinical work on GLP-1 receptor agonists, phosphodiesterase inhibitors, glucocorticoid receptor antagonists, nociception agonists and antagonists, and CRF1 antagonists. Clinically approved medications are available for each of these drug classes. I conclude by advocating a translational approach in which drugs are evaluated highly congruent preclinical models and human laboratory studies. Once translation is established, I suggest the burden is to develop hypothesis-based therapeutic interventions maximizing the impact of the confirmed pharmacotherapeutic effects in the context of additional variables falling outside the model.

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.

Systematic review: Baclofen dosing protocols for alcohol use disorders used in observational studies

The popularity of baclofen as an anti-craving agent in the treatment of alcohol use disorders (AUDs) has increased, especially in patients with established liver disease. However, evidence-based guidelines to inform practice are lacking. The aim of this systematic review is explore the prescribing practices of baclofen in AUD treatment. Electronic databases were searched for relevant articles from 2002. Assessment of eligibility criteria for inclusion was performed independently by two investigators. The main outcomes of interest were maximum dose, starting dose, titration regimen, effectiveness, and tolerability. Twenty-five studies reporting outcomes in 613 patients treated with baclofen for an AUD were identified. Starting doses ranged between 5 and 50mg/d. Titration was study-dependent, and doses were increased until either therapeutic target (abstinence or study-defined low risk drinking) was achieved or adverse events resulted in a dose reduction or discontinuation. The maximum dose for individual patients ranged between 20 and 630mg/d. Seven studies reported at least one patient using >300mg/d. In studies with 10 or more patients, we found a negative correlation between dose and proportion of patients achieving the therapeutic goal. However, this was skewed by one study. A range of serious adverse events were reported. Most were reported at doses over 100mg/d, but others presented at lower doses. Baclofen is a promising therapeutic in this area. Evidence is required, however, to support practitioners in prescribing doses that optimise outcomes and reduce adverse events.

Baclofen and naltrexone effects on alcohol self-administration: Comparison of treatment initiated during abstinence or ongoing alcohol access in baboons

BACKGROUND

Baclofen, a GABA_B receptor agonist, is under investigation as a pharmacotherapy for alcohol use disorder. Treatment with a pharmacotherapeutic can be initiated during alcohol abstinence or active drinking, which may influence treatment outcomes. This study examined whether baclofen treatment initiated and maintained during alcohol abstinence would reduce alcohol seeking and self-administration upon return to alcohol access, and whether effects differed from treatment initiated and maintained during ongoing alcohol access. Naltrexone was tested under similar conditions for comparison.

METHODS

Five baboons self-administered alcohol under a three-component chained schedule of reinforcement that modeled periods of anticipation (Component 1), seeking (Component 2), and consumption (Component 3). Alcohol was only available in Component 3. In Experiment 1, baclofen (0.1-1.8mg/kg) or naltrexone (1.0-5.6mg/kg) was administered daily beginning on the first day of a 5-day abstinence period and treatment was continued for 5days of alcohol access. In Experiment 2, selected doses of both drugs were administered during ongoing alcohol access.

RESULTS

When treatment was initiated during alcohol abstinence, baclofen and naltrexone did not significantly reduce total alcohol intake (g/kg) or alcohol seeking. In comparison, when treatment was initiated during ongoing alcohol access, both baclofen (1.8mg/kg) and naltrexone (3.2 and 5.6mg/kg) significantly reduced total alcohol intake (g/kg). Naltrexone (5.6mg/kg), but not baclofen, significantly reduced alcohol seeking.

CONCLUSIONS

Initiation of baclofen treatment (or other alcohol use disorder treatments) during abstinence or active drinking may be an important factor in influencing efficacy and appropriate dose selection.

A prospective cohort study examining the effectiveness of baclofen in the maintenance of abstinence in alcohol use disorder patients attending a joint liver and alcohol treatment clinic

OBJECTIVE

Alcohol-related liver disease (ARLD) is the leading cause of alcohol-related mortality in the UK. Helping patients with ARLD to stop drinking is an important treatment goal. The aim of this study is to explore baclofen's utility in maintaining abstinence.

METHODS - A PROSPECTIVE COHORT STUDY

Patients with ARLD were commenced on baclofen; the dose was titrated according to tolerability and response up to 30 mg three times daily. Severity of physical dependence and biochemical markers of liver injury were assessed at baseline, 3 months, and 12 months.

RESULTS

Length of follow-up differed. Of 219 patients in the original cohort, 186 and 113 were evaluated at 3 months and 12 months, respectively. Loss to follow-up was due to death, baclofen non-adherence, and failure to attend appointments. Comparison of baseline and 1-year biochemical markers showed significant reductions in GGT (median change = 82.0; 95% CI = -149.0 to -40.0; p < 0.0005), ALT (-10.5; 95% CI = -16.5 to -5.0; p = 0.001), and bilirubin (-4.5; 95% CI = -7.0 to -2.0; p < 0.001). The proportion of eligible patients reporting complete abstinence at 3 and 12 months was 55% and 53%, respectively. A significant reduction in alcohol consumption and Severity of Alcohol Dependence Questionnaire score was observed at both follow-up time points.

CONCLUSION

Adherence to the baclofen was good, and it had a positive impact on measures of alcohol consumption. A limitation of our study is its observational nature. Further randomized studies alongside investigation of dosing strategies are required.

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.

Interventions for tobacco use cessation in people in treatment for or recovery from substance use disorders

BACKGROUND

Smoking rates in people with alcohol and other drug dependencies are two to four times those of the general population. Concurrent treatment of tobacco dependence has been limited due to concern that these interventions are not successful in this population or that recovery from other addictions could be compromised if tobacco cessation was combined with other drug dependency treatment.

OBJECTIVES

To evaluate whether interventions for tobacco cessation are associated with tobacco abstinence for people in concurrent treatment for or in recovery from alcohol and other drug dependence.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and clinicaltrials.gov databases, with the most recent search completed in August 2016. A grey literature search of conference abstracts from the Society on Nicotine Research and Treatment and the ProQuest database of digital dissertations yielded one additional study, which was excluded.

SELECTION CRITERIA

We included randomised controlled trials assessing tobacco cessation interventions among people in concurrent treatment for alcohol or other drug dependence or in outpatient recovery programmes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study risk of bias and extracted data. We resolved disagreements by consensus. The primary outcome was abstinence from tobacco use at the longest period of follow-up, and the secondary outcome was abstinence from alcohol or other drugs, or both. We reported the strictest definition of abstinence. We summarised effects as risk ratios and 95% confidence intervals (CI). Two clustered studies did not provide intraclass correlation coefficients, and were excluded from the sensitivity analysis. We used the I² statistic to assess heterogeneity.

MAIN RESULTS

Thirty-five randomised controlled trials, one ongoing, involving 5796 participants met the criteria for inclusion in this review. Included studies assessed the efficacy of tobacco cessation interventions, including counselling, and pharmacotherapy consisting of nicotine replacement therapy (NRT) or non-NRT, or the two combined, in both inpatient and outpatient settings for participants in treatment and in recovery. Most studies did not report information to assess the risk of allocation, selection, and attrition bias, and were classified as unclear.Analyses considered the nature of the intervention, whether participants were in treatment or recovery and the type of dependency. Of the 34 studies included in the meta-analysis, 11 assessed counselling, 11 assessed pharmacotherapy, and 12 assessed counselling in combination with pharmacotherapy, compared to usual care or no intervention. Tobacco cessation interventions were significantly associated with tobacco abstinence for two types of interventions. Pharmacotherapy appeared to increase tobacco abstinence (RR 1.60, 95% CI 1.22 to 2.12, 11 studies, 1808 participants, low quality evidence), as did combined counselling and pharmacotherapy (RR 1.74, 95% CI 1.39 to 2.18, 12 studies, 2229 participants, low quality evidence) at the period of longest follow-up, which ranged from six weeks to 18 months. There was moderate evidence of heterogeneity (I² = 56% with pharmacotherapy and 43% with counselling plus pharmacotherapy). Counselling interventions did not significantly increase tobacco abstinence (RR 1.33, 95% CI 0.90 to 1.95).Interventions were significantly associated with tobacco abstinence for both people in treatment (RR 1.99, 95% CI 1.59 to 2.50) and people in recovery (RR 1.33, 95% CI 1.06 to 1.67), and for people with alcohol dependence (RR 1.47, 95% CI 1.20 to 1.81) and people with other drug dependencies (RR 1.85, 95% CI 1.43 to 2.40).Offering tobacco cessation therapy to people in treatment or recovery for other drug dependence was not associated with a difference in abstinence rates from alcohol and other drugs (RR 0.97, 95% CI 0.91 to 1.03, 11 studies, 2231 participants, moderate evidence of heterogeneity (I² = 66%)).Data on adverse effect of the interventions were limited.

AUTHORS' CONCLUSIONS

The studies included in this review suggest that providing tobacco cessation interventions targeted to smokers in treatment and recovery for alcohol and other drug dependencies increases tobacco abstinence. There was no evidence that providing interventions for tobacco cessation affected abstinence from alcohol and other drugs. The association between tobacco cessation interventions and tobacco abstinence was consistent for both pharmacotherapy and combined counselling and pharmacotherapy, for participants both in treatment and in recovery, and for people with alcohol dependency or other drug dependency. The evidence for the interventions was low quality due primarily to incomplete reporting of the risks of bias and clinical heterogeneity in the nature of treatment. Certain results were sensitive to the length of follow-up or the type of pharmacotherapy, suggesting that further research is warranted regarding whether tobacco cessation interventions are associated with tobacco abstinence for people in recovery, and the outcomes associated with NRT versus non-NRT or combined pharmacotherapy. Overall, the results suggest that tobacco cessation interventions incorporating pharmacotherapy should be incorporated into clinical practice to reduce tobacco addiction among people in treatment for or recovery from alcohol and other drug dependence.

New Pharmacological Agents to Aid Smoking Cessation and Tobacco Harm Reduction: What Has Been Investigated, and What Is in the Pipeline?

A wide range of support is available to help smokers to quit and to aid attempts at harm reduction, including three first-line smoking cessation medications: nicotine replacement therapy, varenicline and bupropion. Despite the efficacy of these, there is a continual need to diversify the range of medications so that the needs of tobacco users are met. This paper compares the first-line smoking cessation medications with (1) two variants of these existing products: new galenic formulations of varenicline and novel nicotine delivery devices; and (2) 24 alternative products: cytisine (novel outside Central and Eastern Europe), nortriptyline, other tricyclic antidepressants, electronic cigarettes, clonidine (an anxiolytic), other anxiolytics (e.g. buspirone), selective serotonin reuptake inhibitors, supplements (e.g. St John's wort), silver acetate, Nicobrevin, modafinil, venlafaxine, monoamine oxidase inhibitors (MAOIs), opioid antagonists, nicotinic acetylcholine receptor (nAChR) antagonists, glucose tablets, selective cannabinoid type 1 receptor antagonists, nicotine vaccines, drugs that affect gamma-aminobutyric acid (GABA) transmission, drugs that affect N-methyl-D-aspartate (NMDA) receptors, dopamine agonists (e.g. levodopa), pioglitazone (Actos; OMS405), noradrenaline reuptake inhibitors and the weight management drug lorcaserin. Six 'ESCUSE' criteria-relative efficacy, relative safety, relative cost, relative use (overall impact of effective medication use), relative scope (ability to serve new groups of patients) and relative ease of use-are used. Many of these products are in the early stages of clinical trials; however, cytisine looks most promising in having established efficacy and safety with low cost. Electronic cigarettes have become very popular, appear to be efficacious and are safer than smoking, but issues of continued dependence and possible harms need to be considered.

Developing a model of limited-access nicotine consumption in C57Bl/6J mice

Although United States smoking rates have been on the decline over the past few decades, cigarette smoking still poses a critical health and economic threat. Very few treatment options for smoking exist, and many of them do not lead to long-term abstinence. Preclinical models are necessary for understanding the effects of nicotine and developing treatments. Current self-administration models of nicotine intake may require surgical procedures and often result in low levels of intake. Further, they do not lend themselves to investigating treatments. The current study sought to develop a limited-access model of nicotine intake using the Drinking-in-the-Dark paradigm, which results in high levels of binge-like ethanol consumption that can be pharmacologically manipulated. The present study found that mice will consume nicotine under a range of parameters. Intakes under the preferred condition of 0.14mg/ml nicotine in 0.2% saccharin reached over 6mg/kg in two hours and were reduced by an injection of R(+)-baclofen. Mecamylamine did not significantly affect nicotine consumption. As nicotine and ethanol are often co-abused, nicotine intake was also tested in the presence of ethanol. When presented in the same bottle, mice altered nicotine intake under various concentrations to maintain consistent levels of ethanol intake. When nicotine and ethanol were presented in separate bottles, mice greatly reduced their nicotine intake while maintaining ethanol intake. In conclusion, these studies characterize a novel model of limited-access nicotine intake that can be pharmacologically manipulated.

Emerging Pharmacologic Treatments for Adolescent Substance Use: Challenges and New Directions

Adolescence is a key period in the development of substance use and misuse. Substance use typically begins during adolescence and prevalence rates for many substance use disorders peak before age 21 years. Yet, despite clinical demand, treatments for youth rely almost entirely on psychosocial interventions that yield only modest benefit. One potential way to improve treatment effects is to augment the best available psychosocial interventions with pharmacotherapy. Although pharmacotherapy research has advanced care for adults with substance use disorders, no medication is indicated for adolescents and controlled trials with teenagers are scant. Optimizing treatments for youth will require closing this important gap in medication development research. In this paper we review the paucity of pharmacotherapy research for adolescent substance misuse, and we discuss how we can leverage human laboratory paradigms and technology to advance our understanding regarding if and how medications may improve treatment options for youths.