Pharmacotherapy of binge-eating disorder: a review

An experimental protocol for a double-blind placebo-controlled evaluation of the effectiveness of oral naltrexone in management of adolescent eating disorders

BACKGROUND

This double-blind, placebo-controlled study evaluates the effectiveness of oral naltrexone in adolescents and young adults with eating disorders (EDs) characterized by purging with or without binge-eating behaviors. We hypothesize that participants receiving oral naltrexone will demonstrate greater improvements in body mass index in underweight participants and self-reported ED symptomatology compared to placebo.

METHODS

Thirty individuals receiving treatment in a partial hospitalization program for EDs with diagnoses of anorexia nervosa binge-eating/purging type, bulimia nervosa, or purging disorder will receive six weeks of either placebo or oral naltrexone. Participants will complete a battery of self-report measures and laboratory safety monitoring every three weeks in addition to standard of medical care for treatment environment.

RESULTS

Analysis will compare outcomes at weeks three and six, and follow-up at nine weeks and six-months across the oral naltrexone and placebo groups. Main effects for time will examine improvements over the course of treatment for all participants, while group × time interactions will examine differences in the rate of change over time between study arms.

CONCLUSIONS

We hypothesize that participants receiving oral naltrexone will experience more rapid improvements in symptom severity and weight restoration compared to placebo across study time points. There are very few medications with high-quality data demonstrating both safety and efficacy in the treatment of eating disorders. The authors theorize this study will demonstrate a clinically significant effect of oral naltrexone on impulsive-type EDs and support its use as an effective option for treatment augmentation.

Brain serotonin deficiency and fluoxetine lead to sex-specific effects on binge-like food consumption in mice

RATIONALE

Although pharmacotherapies are often effective in reducing binge eating in conditions such as bulimia nervosa and binge eating disorder, subsets of patients do not benefit sufficiently from existing treatments, and the reasons for treatment failure remain unclear.

OBJECTIVES

This study aimed to evaluate whether genetic reductions in brain serotonin influence binge eating and/or the ability of fluoxetine, a selective serotonin reuptake inhibitor, to reduce binge eating in mice.

METHODS

This study used a validated model of binge-like consumption of high-fat diet to compare binge-like food intake in control and fluoxetine-treated wild-type and serotonin-deficient mice from the tryptophan hydroxylase 2 (R439H) knock-in line. In addition, real-time PCR was used to evaluate potential genotype and sex differences in the effects of fluoxetine on gene expression in the raphe nucleus.

RESULTS

The results reveal that brain serotonin deficiency is sufficient to increase binge eating in males, but not females. However, while chronic fluoxetine reduced binge eating in both genotypes of males and in wild-type females, it failed to reduce binge eating in serotonin-deficient females. Transcriptional responses to chronic fluoxetine were also characterized by sex and genotype differences.

CONCLUSIONS

Overall, this study revealed significant sex differences in the effects of fluoxetine and brain serotonin deficiency on binge-like food intake and suggests that low brain serotonin could impact eating disorders both by promoting binge eating and by limiting the efficacy of fluoxetine to reduce binge eating.

Lisdexamfetamine and binge-eating disorder: A systematic review and meta-analysis of the preclinical and clinical data with a focus on mechanism of drug action in treating the disorder

Binge-Eating Disorder (BED) is the most common eating disorder in the United States. Lisdexamfetamine (LDX) was approved in 2015 by the FDA for treatment of BED and is the only drug approved for treating the disorder. There has been no systematic evaluation of the published clinical and preclinical evidence for efficacy of LDX in treating BED and the mechanisms responsible for the therapeutic action of the drug. To address this gap, we conducted a systematic review and meta-analysis using PRISMA guidelines. Fourteen clinical and seven preclinical articles were included. There is consistent evidence from clinical studies that LDX is an effective treatment for BED and that the drug reduces the BED symptoms and body weight of patients with the disorder. There is also consistent evidence from preclinical studies that LDX reduces food intake but no consistent evidence for a preferential reduction of palatable food consumption by the drug in rodents. The evidence on mechanism of action is more limited and suggests LDX may reduce binge eating by a combination of effects on appetite/satiety, reward, and cognitive processes, including attention and impulsivity/inhibition, that are mediated by catecholamine and serotonin mechanisms in the brain. There is an urgent need for adequately powered, placebo-controlled, behavioural and neuroimaging studies with LDX (recruiting patients and/or individuals with subclinical BED symptoms) to further investigate the mechanism of action of the drug in treating BED. An improved understanding of the behavioural and neurochemical mechanisms of action of LDX could lead to the development of improved drug therapies to treat BED.

A double-blind, placebo-controlled study of vortioxetine in the treatment of binge-eating disorder

BACKGROUND

Binge-eating disorder (BED) is associated with impaired quality of life and has a number of untoward public health associations. There are few established pharmacological treatments for BED, and available options are not suitable for all individuals. Vortioxetine is a recently developed pharmacological agent with effects on the serotonergic but also other neurochemical systems, which has yet to be evaluated in this context.

METHOD

Eighty adults with BED were recruited for a double-blind, placebo-controlled study. Participants received 12-week treatment with vortioxetine (10 mg/day for 1 week, then increasing to 20 mg/day) or placebo in a parallel design. The primary efficacy outcome measures were binge-eating frequency and weight. Safety data were collected. Effects of active versus placebo treatment were characterized using linear repeated measures models.

RESULTS

Both vortioxetine and placebo treatment were associated with significant reductions in binge-eating frequency. Vortioxetine did not differentiate significantly from placebo on any efficacy measure. Frequency of adverse events did not differ between groups.

DISCUSSION

Vortioxetine was not more effective than placebo in the treatment of BED. The ability to detect pharmacological treatment benefit may have been hindered by the relatively high placebo response and drop out. Future work should seek to better understand and predict placebo response in BED, with a view to more targeted treatment interventions and, potentially, sample enrichment.

Binge-Eating Disorder in Adults: A Systematic Review and Meta-analysis

BACKGROUND

The best treatment options for binge-eating disorder are unclear.

PURPOSE

To summarize evidence about the benefits and harms of psychological and pharmacologic therapies for adults with binge-eating disorder.

DATA SOURCES

English-language publications in EMBASE, the Cochrane Library, Academic OneFile, CINAHL, and ClinicalTrials.gov through 18 November 2015, and in MEDLINE through 12 May 2016.

STUDY SELECTION

9 waitlist-controlled psychological trials and 25 placebo-controlled trials that evaluated pharmacologic (n = 19) or combination (n = 6) treatment. All were randomized trials with low or medium risk of bias.

DATA EXTRACTION

2 reviewers independently extracted trial data, assessed risk of bias, and graded strength of evidence.

DATA SYNTHESIS

Therapist-led cognitive behavioral therapy, lisdexamfetamine, and second-generation antidepressants (SGAs) decreased binge-eating frequency and increased binge-eating abstinence (relative risk, 4.95 [95% CI, 3.06 to 8.00], 2.61 [CI, 2.04 to 3.33], and 1.67 [CI, 1.24 to 2.26], respectively). Lisdexamfetamine (mean difference [MD], -6.50 [CI, -8.82 to -4.18]) and SGAs (MD, -3.84 [CI, -6.55 to -1.13]) reduced binge-eating-related obsessions and compulsions, and SGAs reduced symptoms of depression (MD, -1.97 [CI, -3.67 to -0.28]). Headache, gastrointestinal upset, sleep disturbance, and sympathetic nervous system arousal occurred more frequently with lisdexamfetamine than placebo (relative risk range, 1.63 to 4.28). Other forms of cognitive behavioral therapy and topiramate also increased abstinence and reduced binge-eating frequency and related psychopathology. Topiramate reduced weight and increased sympathetic nervous system arousal, and lisdexamfetamine reduced weight and appetite.

LIMITATIONS

Most study participants were overweight or obese white women aged 20 to 40 years. Many treatments were examined only in single studies. Outcomes were measured inconsistently across trials and rarely assessed beyond end of treatment.

CONCLUSION

Cognitive behavioral therapy, lisdexamfetamine, SGAs, and topiramate reduced binge eating and related psychopathology, and lisdexamfetamine and topiramate reduced weight in adults with binge-eating disorder.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.