Study protocol and rationale for a randomized double-blinded crossover trial of phentermine-topiramate ER versus placebo to treat binge eating disorder and bulimia nervosa

Efficacy of pharmacotherapies for bulimia nervosa: a systematic review and meta-analysis

OBJECTIVE

The main purpose was to evaluate the efficacy and tolerability of different medications used to treat bulimia nervosa (BN).

METHODS

Randomized controlled trials (RCTs) were identified from published sources through searches in PubMed, Cochrane Library, Web of Science, and Embase from inception to November 2022. Primary outcomes were changes in the frequency of binge eating episodes and vomiting episodes from baseline to endpoint. Secondary outcomes were differences in the improvement of scores in depressive symptoms, tolerability (dropout due to adverse events) and weight change.

RESULTS

The literature search ultimately included 11 drugs, 33 studies and 6 types of drugs, 8 trials with TCAs (imipramine, desipramine), 14 with SSRIs (fluoxetine, citalopram and fluvoxamine), 6 with MAOIs (phenelzine, moclobemide and brofaromine), 3 with antiepileptic drugs (topiramate), 1 with mood stabilizers (lithium), and 1 with amphetamine-type appetite suppressant (fenfluramine). The reduction in binge eating episodes was more likely due to these drugs than the placebo, and the SMD was -0.4 (95% CI -0.61 ~ -0.19); the changes in the frequency of vomiting episodes (SMD = -0.16, 95% CI -0.3 ~ -0.03); weight (WMD = -3.05, 95% CI -5.97 ~ -0.13); and depressive symptoms (SMD = -0.32, 95% CI -0.51 ~ -0.13). However, no significant difference was found in dropout due to adverse events (RR = 1.66, 95% CI 1.14 ~ 2.41).

CONCLUSIONS

This meta-analysis indicates that most pharmacotherapies decreased the frequency of binge-eating and vomiting episodes, body weight, and depressive symptoms in BN patients, but the efficacy was not significant. In each drug the efficacy is different, treating different aspects, different symptoms to improve the clinical performance of bulimia nervosa.

A randomized, placebo-controlled crossover trial of phentermine-topiramate ER in patients with binge-eating disorder and bulimia nervosa

OBJECTIVE

Open trials suggest phentermine/topiramate ER (PHEN/TPM-ER), food and drug administration (FDA) approved for obesity, has utility for binge eating. With no randomized controlled trials (RCTs) yet performed, this trial aimed to evaluate PHEN/TPM-ERs efficacy and safety in a crossover RCT for patients with binge-eating disorder (BED) or bulimia nervosa (BN).

METHOD

Participants were randomized to 12-weeks PHEN/TPM-ER (3.75 mg/23 mg-15 mg/92 mg) or placebo followed by 2-weeks drug washout, then 12-week crossover. Demographics, vitals, eating disorder behaviors, mood, and side effects were measured. Primary outcome was objective binge-eating (OBE) days/4-weeks; secondary outcomes included binge abstinence. Mixed-effect models estimated treatment effects, with fixed effects adjusting for treatment, study period, and diagnosis.

RESULTS

The 22 adults (BED = 18, BN = 4) were female (96%), Caucasian (55%), aged 42.9 (SD = 10.1) years with body mass index = 31.1 (SD = 6.2) kg/m2 . Baseline OBE days/4-weeks decreased from 16.2 (SD = 7.8) to 4.2 (SD = 8.4) after PHEN/TPM-ER versus 13.2 (SD = 9.1) after placebo (p < .0001), with abstinence rates = 63.6% on PHEN/TPM-ER versus 9.1% on placebo (p < .0001). Weight changes = -5.8 kg on PHEN/ TPM-ER versus +0.4 kg on placebo. Drop-out = 2 (9%) on PHEN/TPM-ER and 2 (9%) on placebo, with few side effects. Vital sign changes with PHEN/TPM-ER were minimal and similar to placebo. Responses were not significantly different for BED versus BN.

DISCUSSION

This first RCT to evaluate the efficacy and safety of PHEN/TPM-ER for BED/BN found this drug combination significantly more effective at reducing binge eating than placebo and well tolerated. However, with only four participants with BN, findings regarding the safety of PHEN/TPM-ER in patients with BN must be taken with caution.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT02553824 registered on 9/17/2015. https://clinicaltrials.gov/ct2/show/NCT02553824.

Medications for the treatment of obesity in adolescents

While there are eight medications/combinations approved for the treatment of obesity in adults, the options for the treatment of obesity in adolescents remain limited. Evidence for obesity medication use in adolescents is limited due to the relatively small number of clinical trials that have been completed and the few adolescents that have been included in many of the trials. The goal of this review will be to present the current evidence for the medications approved for adolescents, medications not approved for adolescents but have adolescent data, and medications approved for adults with the prospect for use in adolescents. We will also discuss current limitations and next steps in the exploration of future treatment options.

Investigational drugs for the treatment of binge eating disorder (BED): an update

Introduction: Binge eating disorder (BED) is the most common eating disorder and is frequently associated with psychiatric and medical comorbidities and functional impairment. Although psychological treatments have been the cornerstones of BED treatment, pharmacologic interventions also play an important part of the multimodal management of this condition.Areas covered: This review examines investigational, approved and other pharmacological agents for the treatment of BED. We searched PubMed and clinicaltrials.gov to identify pharmacological interventions for the management of this condition.Expert opinion: BED pharmacological studies have incorporated new drug targets based on our enhanced understanding of the pathophysiology of BED. Neurobiological dysregulation in the reward center and impulse control circuitry and related disturbances in dopamine neurotransmission are among the neurobiological explanations that have been suggested for BED. These mechanisms serve as a pharmacodynamic foundation for the development of new compounds such as lisdexamfetamine (LDX) and dasotraline. Despite these advances, pharmacological trials in BED have numerous challenges that must be overcome. For most compounds studied, larger and more definitive trials is a high priority.

Clinical Considerations Regarding the Use of Obesity Pharmacotherapy in Adolescents with Obesity

A growing number of youth suffer from obesity and in particular severe obesity for which intensive lifestyle intervention does not adequately reduce excess adiposity. A treatment gap exists wherein effective treatment options for an adolescent with severe obesity include intensive lifestyle modification or metabolic and bariatric surgery while the application of obesity pharmacotherapy remains largely underutilized. These youth often present with numerous obesity-related comorbid diseases, including hypertension, dyslipidemia, prediabetes/type 2 diabetes, obstructive sleep apnea, nonalcoholic fatty liver disease, musculoskeletal problems, and psychosocial issues such as depression, anxiety, and social stigmatization. Current pediatric obesity treatment algorithms for pediatric primary care providers focus primarily on intensive lifestyle intervention with escalation of treatment intensity through four stages of intervention. Although a recent surge in the number of Food and Drug Administration-approved medications for obesity treatment has emerged in adults, pharmacotherapy options for youth remain limited. Recognizing treatment and knowledge gaps related to pharmacological agents and the urgent need for more effective treatment strategies in this population, discussed here are the efficacy, safety, and clinical application of obesity pharmacotherapy in youth with obesity based on current literature. Legal ramifications, informed consent regulations, and appropriate off-label use of these medications in pediatrics are included, focusing on prescribing practices and prescriber limits.

Progress in Developing Pharmacologic Agents to Treat Bulimia Nervosa

This paper reviews past and current progress in developing pharmacologic agents for the treatment of individuals with bulimia nervosa (BN). We searched the literature and clinical trial registries for compounds studied in BN, the related condition, binge eating disorder (BED), and preclinical models of binge-eating behavior. Drug classes evaluated included antidepressants, antiepileptic drugs, stimulants and other medications for attention-deficit/hyperactivity disorder, opioid antagonists, and weight loss agents, among others. The only available drugs with established efficacy in BN at this time include antidepressants (especially selective serotonin reuptake inhibitors [SSRIs]) and the antiepileptic topiramate, though the efficacy of these compounds is modest at best. The only medications we found currently receiving empirical study in people with BN were fluoxetine, other serotonergic antidepressants, intranasal naloxone, lisdexamfetamine dimesylate, phentermine-topiramate combination, the antiandrogenic oral contraceptive ethinyl estradiol plus drospirenone, and prazosin. Preclinical models suggest that nociceptin receptor antagonists, the selective serotonin 5-HT2C receptor agonist lorcaserin, monoamine stabilizers, and selective orexin-1 receptor antagonists might be helpful. We found no evidence of a drug developed specifically for the treatment of individuals with BN. Future areas for research in the pharmacotherapy of BN are suggested. Importantly, until drugs are developed specifically for eating disorders, drugs developed for other conditions that are centrally acting and associated with beneficial psychotropic effects and/or reduced appetite or weight loss might be considered for repurposing in BN.